DTU ELECTRICAL ENGINEERING in PROFILE 2013 Introduction

DTU Electrical Engineering in Profi l e 2013 DTU Electrical Engineering in Profi le 2013

Editorial function: Bettina Bork & Kristian Stubkjær

Coordination: Camilla Christiane Hermann

Photography: DTU Elektro, Jens Rosenfeldt, theresonance.com, Th orkild Amdi Christensen, Birgitte Røddik, Venture Cup, Danish Foundation for Entrepreneurship – Young Enterprise, Torben Klint, Eva Helena Andersen, Nils Nielsen, Asger Ladefoged, T. Kaare Smith, Torben Nielsen, Ulrik Jantzen, Sonja Iskov, Lars Bahl, Jørgen Rasmussen, Mickey P. Madsen, Mikkel Adsbøll, Joachim Rode, Evert J. Friberg-Jensen, Benny Johansen

Cover: Jens Rosenfeldt Reproduction and printing: Brande Bladet Design: Artcome

DTU Electrical Engineering Technical University of Denmark Ørsteds Plads, building 349 DK-2800 Kgs. Lyngby www.elektro.dtu.dk E-mail: [email protected]

ISBN 978-87-92465-54-2 Contents

Introduction ...... 2

Awards, honours and appointments ...... 3

Public outreach ...... 5

PhD projects ...... 10

Acoustic Technology ...... 10

Automation and Control ...... 14

Biomedical Engineering ...... 20

Center for Electric Power and Energy ...... 28

Electromagnetic Systems ...... 40

Electronics ...... 48

Hearing Systems ...... 56

Facts and fi gures ...... 62

Advisory board, Management, Publications and Links ...... 63

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Introduction

Welcome to our profi le magazine 2013 illustrating the wide range of activities at DTU Electrical Engineering. Our research is to a high extent refl ected in the more than 80 PhD programs which are currently carried out. Our profi le magazine is therefore organized in brief presentations of each of our seven groups followed by short outlines of the individual PhD programs.

Innovation is high on the agenda in recognition of society’s need for fresh ideas to sustain welfare and prosperity. Our PhD programs strongly support innovation, as many are carried out in fruitful collaboration with both Danish and international partners. Moreover, funding from competitive research grants is oft en obtained in collaboration with industry thereby securing an eﬃ cient exchange of knowledge. In 2012 we generated 11 patent ideas – many leading to new products. Other innovative ideas resulted in prizes and awards as detailed in the section on “Awards and Public Outreach”.

In 2012 our research was evaluated by an international expert panel. We are happy with the outcome showing that we have a competitive edge in many areas. In addition to our many ongoing projects, we have started a host of new research projects and initiatives. Some of these are large, long term eﬀ orts allowing cutting edge research. To mention just a few:

• Th e Danish Advanced Technology Foundation granted a platform project On demand diagnostic Ultrasound Imaging allowing continuation of the leading eff ort in ultrasound imaging • In collaboration with a consortium of companies we inaugurated PowerLabDK (Phase I). It represents one of the world’s most advanced facilities for research into future electric power systems • Our Centre for Applied Hearing Research has secured another four years of sponsorship from the Danish hearing aid industry and moreover – with support from the Oticon Foundation – our Hearing Systems group will establish the new Oticon Centre of Excellence for Hearing and Speech Sciences • Also supported by the Danish hearing aid industry we will set up a Center for Acoustic and Micro Mechanics. Th e center, which is the fi rst of its kind, is a joint eff ort with the DTU Department of Mechanical Engineering • We take part in the Human Brain project, which is one of the two EU Future and Emerging Technologies (FET) Flagship Projects that have obtained funding. We also participate in the Guardian Angels project which we hope will obtain similar funding in the future.

As can be seen in “Facts and fi gures”, we have considerable activities going on in teaching and training. Our study programs continue to be fi lled to capacity. It should be noted that our many student projects at Bachelor and Master levels represent a considerable innovation eff ort to the benefi t of collaborative partners and to society.

We hope you will enjoy reading about the innovative research we engage in, and we look forward to future contact and collaboration.

Professor Kristian Stubkjær Head of Department

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Awards, honours and appointments

Professor Ziolkowski for the Honorary Doctorate. Th e background for Professor Ziolkowski’s nomination is his research within electromagnetic metamaterials and the use hereof within antenna technology to establish the new ﬁ eld of Metamaterial- Inspired Antennas. Th is facilitates highly miniaturized antennas which are essential for modern wireless communication.

The Günther Laukien Prize Adjunct professor Jan Ardenkjær-Larsen was awarded the Günther Laukien Prize for his work in hyperpolarisation. Th e Günther Laukien Prize recognizes cutting-edge experimental Nuclear Magnetic Resonance (NMR) research with a high 2012 best DTU PhD Dissertation Award probability of enabling beneﬁ cial new applications. Jan At the DTU PhD celebration party in October 2012 our then Ardenkjær-Larsen’s research focuses on hyperpolarized MR PhD student Ziwei Ouyang was awarded for the “Best DTU imaging where a technique has been developed which improves PhD Dissertation” of the year. the MR signal by 10,000 - 100,000 times and makes it possible Th e dissertation on “Advances in planar and integrated to determine whether tumours respond to the treatment oﬀ ered. magnetics” was judged to be of a very high quality presenting a number of ground breaking solutions. Ziwei Ouyang is also the author of an impressive number of publications as well as two Honorary Doctor applications for patents during his PhD study.

European Acoustics Association Best Paper and Presentation Award 2012 PhD student Antoni Torras Rosell was honoured with the European Acoustics Association (EAA) Best Paper and Presentation Award 2012 at the International European conference on noise “Euronoise 2012”. Th e paper “A beam forming system based on the acousto-optic eﬀ ect” describes a beam forming system that locates sound sources based on the acousto-optic eﬀ ect, i.e. the interaction between sound and light. Professor Richard W. Ziolkowski, University of Arizona, DTU President Anders Bjarklev and Professor Olav Breinbjerg. Best paper award International Power Electronics In April 2012 professor Richard W. Ziolkowski from University and Motion Control Conference 2012 of Arizona, USA, was nominated Honorary Doctor by Industrial PostDoc Ziwei Ouyang and his DTU Elektro DTU President Anders Bjarklev. Professor Ziolkowski and colleagues received the IPEMC 2012 award for their paper DTU Elektro has a long common history in terms of a close “Decoupled power solution for dual-input isolated DC-DC collaboration with our Electromagnetic Systems group under the converters using four quadrants integrated transformers leadership of Professor Olav Breinbjerg who had recommended (FQIT)”.

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Th eir system makes the treatment easier, ensures better control, and furthermore has the advantage of a simpler installation of apparatus in the operation theatre. So far, the start-up company has spent two years improving the technology from its prototype stage till now.

Venture Cup Idea Competition Th e Venture Cup Idea Competition fi rst prize in the Electro Prize 2012 “Cleantech & Environment” category was given to Kristian David B. Bæk, PhD from DTU Elektro, received the Electro Lindberg-Poulsen for his work in “Ultra-high effi ciency Prize 2012, awarded by the Danish Society of Engineers converters for fuel cell applications”. Th e idea is to increase the (IDA). David B. Bæk was nominated because of his signifi cant effi ciency of the so called power converters to be used in fuel contributions to the electro technical area at a very young cells in vehicles. age. His activities include research in relation to medical Th rough his start-up company, CoolStep, Kristian Lindberg- ultrasound, bio impedance and innovation in relation to Poulsen has developed a strategy which will bring the developing commercial products as well as inspiration and technology closer to a commercial breakthrough. He and leadership. He has shown an exceptional ability to combine his DTU Elektro colleagues, Ziwei Ouyang and Michael theoretical and experimental work with practical engineering. Andersen, strive for a future where our cars run on hydrogen David B. Bæk is employed as Chief Technology Offi cer at Sense converted to electric power in fuel cells instead of on petrol. Th e A/S, a start-up company developing devices for cardiovascular fuel cell technology has been on its way for decades and much diagnostics. eff ort has been put into one of the main issues: an acceptable price level. CoolStep has recently developed a converter unit which can be used for fuel cells, and will make it less expensive to produce more environmentally friendly vehicles.

The ”E-kandidat” Prize Two DTU Elektro BEng students Kasper Fløng Pedersen and Niels Bo Hasselstrøm were each awarded the prestigious ”E-kandidat” prize 2012 as well as DKK 10.000 for their outstanding diploma works. Danish Foundation for Entrepreneurship – Young Th e prize was awarded by the Danish Society of Engineers Enterprise (IDA) in May 2012. Th e prize goes to young talented engineers Two former MSc students from our Biomedical Engineering who have delivered particularly outstanding projects with program were nominated “High Jumpers of the year 2012” signifi cant technical-scientifi c contents. by the Danish Foundation for Entrepreneurship – Young Kasper Fløng received the prize for his project “Sensory and Enterprise. electromyographic amplifi er for use with sub-dermal needle Mads Emil Matthiassen and Rune Paamand have since 2012 and surface electrodes”. Niels Bo Hasselstrøm received the been working on a catheter based system of diagnosis for prize for his project “Battery powered RF unit for measuring patients with heart rate disturbances in their own company, temperature, humidity and CO2”. WiMed.

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Public outreach

New audiological research centre Th anks to a generous donation from the Oticon Foundation, a new research centre ‘Oticon Centre of Excellence for Hearing and Speech Sciences’ has been founded. Professor Torsten Dau will be head of the new centre in parallel with Centre for Applied Hearing research (CAHR). Th e new research centre will have a special focus on cross- disciplinary basic research in the audiological disciplines and will employ a considerable number of scientists, visiting professors, postDocs and PhD students, who will work together on a number of carefully selected basic research projects in the ﬁ eld of audiology. In addition to internal cooperative partners and experts based at DTU, external experts from educational institutions such as Université Paris Descartes in France, University of California, Berkeley, in the USA and Danish Research Centre for Magnetic Resonance, Hvidovre Hospital, will be involved.

World’s most powerful ultrasound scanner Th e world’s most powerful ultrasound scanner, SARUS, is now up and running at our Center for Fast Ultrasound Imaging. Aft er 7 years of developing and constructing, the scanner is now able to conduct no less than 25,000 billion calculations per second and show 3D images of the blood ﬂ ow. SARUS acquires data simultaneously in 1024 channels at 70 MHz/12 bits sampling and generates up to 140 G-bytes of data per second. Th is corresponds to 70,000 HD TV channels. Th e system houses 320 large FPGAs for processing and can Th e central team of the new research centre: implement synthetic aperture imaging and other advanced From right assistant professor Bastian Epp: neural modelling of imaging modes. hearing, associate professor Ewen MacDonald: speech perception With this new epochal scanner, clinicians and researchers can and production, head of centre professor Torsten Dau, PostDoc see 3D images of what is going on inside the body, when it Sébastien Santurette: psychoacoustics, music perception and is actually taking place. Th is is one of the primary beneﬁ ts of functional imaging, and associate professor Tobias Andersen ultrasound: the images are shown in real-time. from Department of Mathematical Modelling: audio-visual integration.

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Martin Lidegaard, Minister for Climate, Energy and Building, Professor and Head of Center Jacob Østergaard and DTU President Anders Bjarklev.

Inauguration of PowerLabDK phase I within the future, sustainable electric power system. Th e main Th e oﬃ cial opening of PowerLabDK took place in March focus is to meet the ambitious goals of an energy system 2012 where the new test facilities for climate friendly energy primarily based on renewable energy. technology was inaugurated in the presence of Martin Lidegaard, Minister for Climate, Energy and Building, and Minister for Trade and Investment many other invited guests. In his speech Martin Lidegaard DTU Elektro received a prominent guest when Pia Olsen greeted PowerLabDK as an important step in the right direction Dyhr, Minister for Trade and Investment and representing to reach the government’s objective of making Denmark the Trade Council and Invest in Denmark, paid a visit to DTU. independent of fossil fuels by 2050. One of PowerLabDK’s Th e Minister has a great interest in DTU and its role in the main goals is the development of the future intelligent research and development of green technologies. DTU’s close electricity system that can handle the future expansion of and successful cooperation with Danish companies is essential renewable energy sources. for creating innovative technological solutions and products PowerLabDK is a world-class experimental platform for which support Danish export green growth and companies’ technology development, testing, demonstrations and training ability to stay competitive in a global market.

From left : DTU Elektro technician F.J. Petersen, Pia Olsen Dyhr, Minister for Trade and Investment, DTU Provost Henrik C. Wegener and Professor, Head of Center Jacob Østergaard.

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 High voltage cables for wind mill parks Real-time operated robots for the meat industry Dong Energy A/S is one of our fi rst customers in the newly A new consortium formed by Danish industrial companies, established PowerLabDK. Under the supervision of Joachim DTU and University of Copenhagen has been granted Holbøll, Deputy Head of Center, high voltage cables are being substantial funding by the Danish Council for Technology and tested for the future supply of the huge off shore wind farms. Innovation Th e results will enable DONG Energy to optimize the technical Our Automation and Control group is part of this consortium design and reliability of cable connections to the wind turbines. with a total budget of DKK 18.2m. Th e development of real-time operated robots will make the handling more cost effi cient and improve the working New dual degrees for MSc students environment at Danish slaughter houses. Th is may also In spring 2012 President of DTU, Anders Bjarklev, and help the Danish industry to sustain the global competitive President of KAIST University in South Korea, Nam Pyo Suh, position. Th e sensor and robot solutions demonstrated by the signed new cooperative agreements that allows students from consortium will be solutions which can be used to solve many the two universities to obtain a dual degree in the fi elds of similar problems, not only within the meat industry, but also in Electrical Engineering, Engineering Acoustics, Engineering work processes in general, where dynamic adjustments to each Design and Applied Mechanics. single work piece is a must. Associate Professors Ole Ravn and Finn Agerkvist visited KAIST in order to fi nalize the dual degree agreements for the master programs in Electrical Engineering and in Engineering Vice Minister Cao Jianlin Acoustics. In April 2012 Dr. Cao Jianlin, Vice Minister of China, Th e new agreement gives our students a unique opportunity visited DTU in order to discuss the perspectives of a future to get a degree from one of the leading technical universities cooperation between China and DTU. During his visit Dr. Cao in the world, and at the same time receive a valuable insight Jianlin visited PowerLabDK where researchers and industry into Asian culture. Th e goal of the dual degree agreement is can test and demonstrate the smart grid systems of the future. to make the students more attractive for Danish companies China faces energy challenges identical to the ones in other wishing to cooperate with Asia. parts of the industrialized world and conducts similar eff orts as to the development of the electric energy system capable of matching the future demand.

From left Maria Runering, DTU, Associate Professor Finn Agerkvist, Professor Jeong-Guon Ih, DTU Dean Martin Bendsøe, From left : Professor, Head of Center Jacob Østergaard, Dr. Cao Anne Mette Holt, DTU, Ann-Bettina Richelsen, DTU, Professor Jianlin, Vice Minister, Head of Department Kristian Stubkjær, Sung Jin Kim, Professor Youngjin Park, Professor Jun Ho Oh and and Vice Dean Hans Hvidtfeldt Larsen. Associate Professor Ole Ravn.

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 The anechoic room in use for musical purposes Toddlers don’t listen to their own voice like adults do Th e Danish pop duo “Hej Matematik” recorded a music video Research carried out by Associate Professor Ewen MacDonald in our anechoic room in January 2012. Th e recording of “Livet shows that when grown-ups and children speak, they listen to i plastik” was a huge success and a completely new experience the sound of their voice and make corrections based on that for the two musicians – the anechoic room being without echo auditory feedback. But new evidence shows that toddlers do and inside vibrations impossible. DTU Dean Martin Vigild not respond to their own voice in quite the same way. Th e welcomed this possibility where engineering competences ﬁ ndings published in “Current Biology” suggest that very meet both social and cultural aspects of our society. young children must have some other strategy to control their speech production. Ewen MacDonald says the results suggest a need to reconsider Portable intuitive ultrasound scanners assumptions about how children make use of auditory A substantial grant of DKK 75m from Th e Danish National feedback. It may be that two-year-olds depend on their parents Advanced Technology Foundation will enable researchers or other people to monitor their speech instead of relying on from our Center for Fast Ultrasound Imaging (CFU) to work their own voice. on the development of portable ultrasound scanners over the next 5 years. Th e project is a cooperation between research groups at DTU, International Conference on Research Infrastructures the companies BK Medical and Meggitt A/S, the Alexandra 2012 in Copenhagen Institute A/S and Copenhagen University Hospital. Th e International Conference on Research Infrastructure 2012 Professor Jørgen Arendt Jensen expects the project to was held under the auspices of the Danish Presidency of the radically improve the application possibilities of ultrasound European Council and co-organized by the Danish Ministry of by rethinking the technologies, so that doctors or nurses can Science, Innovation and Higher Education and the European carry the scanner with them in their pockets. Th e future, Commission. portable scanners will be able to show high solution 4 Over 700 ministers and civil servants from EU were gathered dimensional images of the organs and their functions without in Bella Center in March 2012 to discuss how international time consuming adjustments and training. cooperation on research infrastructures can be more eﬀ ective in the future. Our newest test facility, PowerLabDK, was presented as a state of the art research infrastructure and attracted the attention of ministers and commissioners.

Danish Academy of Technical Sciences seminar In March 2012 the Danish Academy of Technical Sciences (ATV) held a seminar on our premises “Electric power engineering as dynamo for a sustainable energy system”. Th e theme of the seminar was power production, with a special focus on how high voltage current technology can be used as a Professor Jørgen Arendt Jensen. dynamo for a renewable energy system.

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 No less than 65 participants from industry and public organisations took part in the seminar to discuss how to make the best use of the business potential in a power system based on renewable energy. Th e day ended with a panel discussion about the future development opportunities within the fi eld. Sofi e C. Nielsen, then MP, Lasse Emil Korff and Dean of Under- graduate Studies Martin Vigild. Nordic Electric Vehicle Interoperability Centre (Nevic) Minister for Climate, Energy and Building Martin Lidegaard, Lasse Emil Korff won fi rst prize for his project “Digital Control and the mayor of Roskilde, Joy Mogensen, visited our NEVIC in Piezotransformer-based Converters” in the category Course Centre at DTU Risø campus in June 2012. Head of programme Project Master Level. Th e results of Lasse Korff ’s project show Anders Troi introduced the NEVIC project to the visitors. that control of PT-based converters can be done using digital Th e aim of NEVIC is to ensure interoperability for electrical control with close equal performance. vehicles, so the owners can charge their cars at any charging Nikolaj Kammersgaard, Andreas Kastoft and Nicolai Bøegh posts regardless of car brand, type of charging post and EV won second prize for their project “Universal charging from infrastructure operator. PV” in the category Course Project Bachelor Level. Infrastructure operators Better Place, Clever and Clean Charge Th e aim of the project was to design a PV charging system that are all participants in the project. could be an alternative to diesel/gas generators in countries without central power supply.

Advanced Control and Diagnosis workshop Th e 10th European workshop on Advanced Control and Diagnosis hosted by DTU Elektro and AutomationDESIGN took place in November 2012. Th is workshop brought together academics and engineers from various fi elds of automation, and provided the opportunity for researchers and developers to present their Martin Lidegaard, Minister for Climate, Energy and Building, recent developments in control and diagnosis techniques, and Head of Programme Anders Troi, DTU President Anders to present practical applications or open problems. It was also Bjarklev and Mayor of Roskilde Joy Mortensen. a great opportunity for industrial partners to express their needs and priorities and to review the current activities in the H. C. Ørsted PostDoc fi eld of advanced control and diagnosis. In September 2012 Ick-Jae Yoon, PhD, joined our department thanks to a H. C. Ørsted PostDoc grant obtained. Ick-Jae’s research focuses on active wideband matching of electrically International Workshop on Functional Modelling small antennas and electromagnetic energy harvesting. Th is Th e International Workshop on Functional Modelling, IWFM, research constitutes an extension of recent year’s activities took place at DTU in November 2012 hosted by DTU Elektro in antenna miniaturization in our Electromagnetic Systems and visited by participants from all over the world. Functional group. Ick-Jae Yoon obtained his PhD from the University modelling is an exciting research fi eld which is highly relevant of Texas at Austin, USA, and he has worked for 3 years with for the engineering disciplines. It addresses basic questions Samsung Advanced Institute of Technology, South Korea. about the relations between means and ends or purposes and our understanding of complex physical artefacts like industrial systems and infrastructures “Grøn Dyst” student conference Understanding system purposes and functions are prerequisites Four students from DTU Elektro were among the winners of for modelling in engineering and may play a key role in the the 2012 DTU “Grøn Dyst” student competition which focuses integration of process and automation design, integration of on sustainability, climate technology and environment. system design and operation and in risk management.

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 ACOUSTIC TECHNOLOGY T Head of group: Associate Professor FinnJacobsen optic eff optic measurement principle on themodulation isbased sound fi All conventional microphones on asound based fi below. presented projects noise control complicated of sources. Examples such research of are given inthedescriptions thePhD of forming’; make it they to possible visualizesound fi fi sound fi of transmission paths. Developments electronic inmodern A noise reduction project with usually starts theidentifi irregular or disordered voice and study parameters. themodel unhealthy as aresearch moviesHigh-speed used of willbe tool to larynges improve for existing models vibrations, vocal pathological of models tissues. degradation and of including recovery of models fi speakers’ on comfort project PhD health, by co-funded Lund University, Sweden. Th At 2012we initiated PhD theendof project anew on damage modeling and healing processes for voice In thefollowing examples few our research of activities from 2012 have out. singled been University, China, isunderway. and Technology Science of (KAIST) and DTU wasestablished and asimilar arrangement with Harbin off audiblecourses on of practically sound. allaspects We educational program that includes fundamental aswell lecture asadvanced courses and project-oriented Together with our sister group Hearing Systems we off thedevelopment quantitative of human of perception models inperformance halls and perception in • thedevelopment improved of solutions for noise abatement indoors and out doors aswell asnoise of • thedevelopment improved of for technology recording and reproduction sound including of acoustic • threefold: electroacoustic industry, noise consultants, etc. theresearch general In of terms is very thepurpose perhaps slightly more fundamental and lessapplied, acoustics. Compared with many similar research groups throughout theworld theresearch is that accompany any sound fi the course of thisproject outthe course wassingled of by formingtechniques suchasbeam and acoustic holography. In thepapers published during 2012one of eld reconstruction methods based on suchtechniques are based knowneld reconstruction methods as ‘acoustic holography’ and ‘beam er similar educational programs. Recently adual hearing aids. hearing applications,connection with technical advanced e.g., inaudio coding, recognition and speech digital and vibration control invehicles and dwellings rooms of design and transducer technology, acoustic measurement techniques, room acoustics, and building he research at Acoustic Technology on isfocused ect, isdue which that air to thefact isaff therefraction index of eld to a certain extenteld to acertain and thus changes thequantity measured. to be Th elds at numerous positions at thesame timewith microphone arrays. Advanced sound eld. Moreover, technique hasapotential for this visualization advanced nanced bynanced source, the same involves investigating biomechanical Physics Today eproject, continues which aprevious quite successful eld exciting amembrane inevitably disturb the elds, isextremely important which with inconnection degree agreement with Korea Advanced Institute of a laser beam caused by acousto- beam alaser theso-called of but thegroup relations good hasvery with the engineering aspects of ac of engineering aspects er an MSc in er an MSc also cooperate also with international institutions that cation and noise ranking sources of and s have madeit realistic to measure properties as particularly promising. Engineering Acoustics ected byected thedensity fl is is not the case if the isnot if thecase oustics, electroacoustics , atwo-year uctuations Th ere are many similarities between measurements with arrays of microphones and generation of sound with arrays of loudspeakers. Th us a parallel development in sound reproduction technology based on arrays of loudspeakers has made it possible and realistic to control sound fi elds rather than just sound signals and, for example, generate “sound zones” with diff erent acoustic programmes that do not disturb each other in ordinary living rooms. Results from an ongoing postdoc project are very promising.

Damage and healing processes for voice health; high speed camera and biomechanical models

It is common to detect voice problems when repetitive high voice loads occur, since the vocal folds experience damage at high cumulative loads. The degradation that aff ects the vibrations of the vocal folds can sometimes be identifi ed by means of a high-speed camera; overloading of the vocal tract leads to abrasion of the tissue, and consequently, to superfi cial changes and modifi cation of the normal oscillatory pattern.

In this recently initiated project biomechanical models of pathological vocal vibrations, including models of degradation and recovery of tissues, are investigated. High-speed movies of unhealthy larynges will be used as a research tool to improve the existing models for irregular or disordered voice and study the model parameters.

The project is expected to generate objective clinical methods to analyze high-speed movies of vocal folds vibrations, in order to identify subjects with voice dysfunctions caused by prolonged overload voicing.

To be completed: 2015

Alba Granados Corsellas Project co-funded by Lund University, Sweden

New measurement techniques: Optical methods for characterizing sound fi elds

One of the fundamental problems in measuring the quantities that describe a sound fi eld is the infl uence of the transducer on the sound fi eld itself. Typically, this infl uence is assumed to be negligible when the size of the transducer is small compared with the wavelength of the sound wave or is rendered negligible by using a transducer-based correction that depends on the frequency. Either solution introduces additional uncertainties to the measurement process.

The use of optical techniques may help overcoming this problem because the sensing element is not a bulk transducer but a beam of light that does not infl uence the sound fi eld, thus giving the actual value of the acoustic quantities. The purpose of the project is to develop a set of methodologies for the application of optical, laser-based techniques to the measurement, characterization and visualization of sound fi elds.

The results are expected to demonstrate that optical-based measurements are possible with a precision similar to that of well-established classical measurement techniques.

Antoni Torras Rosell To be completed: 2013 Danish Fundamental Metrology, Industrial PhD

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Sound source identifi cation with new acoustic array technology

Near fi eld acoustic holography is a sound source identifi cation technique that makes it possible to visualize the acoustic fi eld close to a sound source. The technique makes use of transducer-array measurements in order to reconstruct the sound fi eld in a three-dimensional space. The resulting visualization provides valuable information about the source and how it radiates sound.

This project studies near-fi eld acoustic holography using novel arrays of acoustic transducers, namely pressure- velocity sensor arrays, double-layer arrays and spherical arrays. Such arrays make it possible to overcome some of the limitations of conventional measurement methods. It is of particular interest to investigate holography based on measurement of the particle velocity and the combined measurement of sound pressure and particle velocity.

The study of new array technology in acoustics is crucial for improving sound visualization techniques, which are an essential tool for diagnosing noise problems and studying complex sources of sound.

Completed: 2012 Efrén Fernández Grande DTU funding

Acoustic array methods for identifi cation of noise sources in vehicles

Signal processing techniques based on arrays of acoustic sensors for the localization of sound sources are a powerful tool for the automotive industry, and the industry is currently incorporating systems of arrays of acoustic sensors during the design of vehicles for localizing and identifying sources of noise. Such systems are used for measurements inside vehicles to characterize the noise sources and their eff ect on the comfort of the passengers. Besides, arrays are also used in measurements outside of vehicles for mapping environmental noise and for detection or prevention of structural failures. However, the complexity of these scenarios presents problems for the existing array techniques that need to be analyzed and overcome.

Thus the purpose of this PhD study is to examine array techniques such as delay-and-sum, eigenbeamforming, adaptive beamforming, and deconvolution methods, identify their limitations, and establish an effi cient methodology for integration of the various methods in a single device.

To be completed: 2014

Elisabet Tiana Roig DTU funding

Deconvolution of seismic transient signals using a model based approach

The blind seismic deconvolution problem involves solving for both source and ground data, but it may be assumed that the ground is a stratifi ed medium in which compressional waves and shear waves propagate. The signal model that relates the ground data and source to the seismic measurements is nonlinear and can be described by the elastic wave equations. The model can be simplifi ed and linearized if one assumes acoustic approximations. This leads to a linear model involving both the compressional wave speeds and source parameters.

The purpose of this PhD project is to examine the signal processing methods to solve the blind deconvolution problem by applying some assumptions about the signal model (linear model; nonlinear model). We shall investigate linear inversion methods that include the beam forming method, and nonlinear inversion methods such as Bayesian inversion, the nonlinear least squares, and identify their advantages and limitations when localizing underground seismic source from measurements made by geophones deployed on ground surface.

This investigation can yield an effi cient and more accurate methodology for seismic localization for integrating the signal model data into the localization problem. Geok Lian Oh To be completed: 2014

Project co-funded by DSO National Laboratories, Singapore

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Nonlinear balanced-armature receivers

Nonlinear distortion due to the loudspeaker in a hearing aid lowers the signal-to-noise ratio in the acoustic output and may degrade the hearing aid user’s ability to understand speech. The balanced-armature type loudspeakers predominantly used in hearing aids are inherently nonlinear devices, since any displacement of the loudspeaker diaphragm inevitably changes the magnetic and the electrical characteristics of the loudspeaker.

This project proposes to identify, model and control the key nonlinearities in miniature balanced-armature loudspeakers. An accurate model of the nonlinear behaviour of these loudspeakers will make it possible to design loudspeakers with less distortion and/or increased effi ciency. This may be achieved by improved design and/or by active nonlinear compensation applied to the signal before it enters the loudspeaker. The goal is thus to create balanced-armature loudspeakers with reduced distortion which may ultimately result in increased speech intelligibility for the hearing aid user.

To be completed: 2013

Joe Jensen Sonion A/S, Industrial PhD

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 AUTOMATION AND CONTROL T and theDTU research groups at Automation and and online operations. A joint cooperation University Beijing between Petroleum of Engineering automation processes, design systems for and confi knowledge-based and consulting projects for companies Danish leading within automation technologies. included Projects AutomationDESIGN hascontinued its activities throughout with theindustry 2012, including innovation Engineering and other DTU groups and centres. automationwith DTUwithinof design systems, AutomationDESIGN asagateway acts for and other theindustry external for partners collaboration Furthermore we exchange PhD students and MSc with numerous universities inEurope and USA. reactor project at Institute for Technology Energy inNorway, and Harbin Engineering University, China. groups at DTU. Internationally we have cooperation with NTNUTrondheim, Norway, theOECD Halden PhD projects and MSc aswell aswith Center for Power Electric (CEE)and and other Energy research Th collaboration with theMITMedia Lab. LEGO prototypes on play based studies and co-creation with children. Th Advanced Technology Foundation with LEGOand Advance A/S hasiteratively anumber developed of within the fi Centrethe for Playware, istoattract largest the strategy the companies research and best the laboratories play, in music, third World up sport, teaching, rehabilitation, etc.opportunities development, building In Th interactive may technology provide motivation for any citizen to perform diff In our research cross-disciplinary Centre for Playware, robotics and ison of thefocus how playful aspects the control sensor based essential knowledge of generic and soft knowledge of project RealRobot with applications in2012. inthemeat wasstarted which industry We contribute with surroundings. Sensor-based real-time control indu of in order to obtain safe and reliable behaviours faults inthepresence changes of or unexpected in Robots that operate innatural or changing environments to cope with need complexity and variety important information from previously unknown, complex systems. project isan excellentservice example how thesystems of approach to rapidly used can be extract Th research are generic by nature, and are they oft and to methods increase availability, reliability and safe is asystems approach toanalysis, and design synthesis on automated systems ison and theory focus the systems inautomationbased and decision-support systems for plant-wide diagnosis. Th dynamics, fault-tolerant control and diagnosis, sensor fusion, applications agents, of and knowledge- Th autonomous vehicles, industrial systems and processes, marine aswell vessels asplayware. Head of group: Associate Professor OleRavn egroup cooperates and with process theenergy indu ecombination artifi modern of e scrutiny of theIC4 escrutiny trains’ of braking system done for DSB –theDanish State Railways –asapublic ecompetences thegroup of include and modeling control systems with of discrete or continuous Mobotware Mobotware control and supervision of technical systems.control technical of and supervision At present application main areas of are robotics and he Automation and Control Group performs research and teaching and inmethods technologies for eld to collaboration. As an example, theModular Playware Technology project by funded the soft ware platform conceived by thegroup. cial intelligence, modular robotics and entertainment provide will novel en applicable towiderareas than pure ones. technical and promotes collaboration DTUElectrical between Control and CAPECinthearea online hazard of strial robots theinnovation isthemain themeof ty of industrial systemsty of and processes. Results of stries and thetransport through sector industrial guration automation of systems eproject to aclose led hasalso ware frameworks like ROS and erent interaction. kindsof eapproach taken risk monitoring has been initiated. An international workshop IWFM on functional modeling was hosted with participation of researchers from Japan, China, Finland, Sweden, Norway and Denmark.

On the educational side activities in robotics at DTU have been concentrated in our group enabling a new and restructured set of basic and high-level courses being developed and executed in cooperation with other departments at DTU. Th is makes a very strong technological basis and in combination with the facilities at the Centre for Playware have given synergies in terms of both research and education for Automation and Control.

Situation assessment for mobile robots

In scientifi c and popular literature, the emergence of intelligent service robots outside of laboratories has been predicted repeatedly for the last 10 years. Yet we still do not see intelligent service robots in our homes, in our workplace or at the shopping malls. The reason is that reliable operation in dynamic and indeterministic environments is a huge challenge, not only for the navigation systems but also for handling unplanned and even unexpected events.

In cooperation with the Danish Technological Institute, the project aims at developing methods and techniques for situation assessment for mobile robot systems in general. By understanding the situation of a robot, unexpected errors can be resolved or even avoided. Based on signal processing, sensor fusion and artifi cial intelligence (AI), the project will investigate how a general situation modelling framework and architecture can be developed and applied.

Commercial success of service robots relies on handling of errors in a new general sense. This project will contribute with methodology to make a robotic future one step closer.

To be completed: 2013

Anders Billesø Beck Danish Technological Institute, Industrial PhD

Wide-Area emergency control in power transmission

Visions for a society with minimal dependency on fossil fuels require a large share of electric power production from sustainable energy sources. A power production that is subject to prevailing weather conditions can introduce rapid changes in the system operating conditions, resulting in the need of fast coordination of control actions using wide- area system measurements for security assessment and control.

This PhD project will study the dynamic behaviour and identify the needed control actions of the transmission system when close to, or already into, emergency conditions, where a blackout is the likely consequence if no immediate action is taken. The considered types of control actions to be applied are e.g., new set points for system states or, in worst case, a wide-area load or generation shedding action.

Algorithms that in real time identify emergency control actions that avoid an emerging system blackout during critical operating conditions will contribute to the development of a sustainable electric power production.

To be completed: 2015 Andreas Søndergaard Pedersen Project co-funded by Energinet.dk and Siemens

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Robust and reliable robot operation in semi-structured environments

The fi eld of robotics is currently very mature for operation in structured environments, such as an assembly line. However, a much wider range of applications require the ability to cope with semi-structured environments, where not everything is controllable or known. This occurs when there are living beings in the environment, or the environment itself is too large or complex to model accurately.

This project aims at using advanced sensors with recent artifi cial intelligence methods to enable robust and reliable robot operation in semi-structured environments. Robot localization, recognition of task-related objects and environment mapping, main challenges of this fi eld, are in focus. Robot vision is central to the approach due to its large information content and relatively lower cost, but other sensors will also be used to support it.

The results are expected to benefi t the society through enabling the use of robots for many tasks that require human labour today.

To be completed: 2013 Enis Bayramo lu ğ Project co-funded by the Ministry for Science, Innovation and Higher Education

Playware for welfare technology

Care products are of increasing interest to both society and private companies as the technology is developing new ways to cope with the growing need for health prevention and rehabilitation. Playware, which is intelligent hardware and software aiming at creating play and playful experiences amongst the users, off ers a unique motivational charac- ter for the welfare technology products.

Being part of the Patient@Home project, where the main goal is to develop technology that supports rehabilitation in homes, this project studies the eff ects of care technology in both institutionalized and non-institutionalized settings to develop a deeper understanding of the similarities and diff erences between these. The research methodology is partly actions research and partly large-scale quantitative testing, and will include randomized controlled trials for playware welfare technology.

Building on play and playware it is possible to create better welfare technology. This project will create the needed knowledge to design the playware welfare technology and the needed methodology to do large-scale quantitative testing. Jari Due Jessen To be completed: 2015

Co-funded by the Danish Agency for Science, Technology and Innovation

Nonlinear, adaptive and fault-tolerant control for electro hydraulic servo systems

This project examines the combination of fault diagnosis with robust control for nonlinear hydraulic-mechanical (NHM) systems. Focus is on fault-tolerant control for NHM systems with applications focused on off shore equipment. The research is also relevant to machining plants, in robotics and for fatigue testing systems. Another objective is to integrate the control issues in the design of a hydraulic-mechanical system.

The project will investigate the usefulness of control methods in this specialised application, including passivity techniques in nonlinear control, adaptive back stepping or H-infi nity controllers and fault-tolerant control. The interaction between controls, hydraulic system design and optimisation techniques will also be considered. The project aims at advancing the theory in nonlinear and fault-tolerant control, as well as validating the theory with experiments.

The results are anticipated to have a large impact on control performance and the reliability of hydraulic-mechanical systems.

Martin Choux Completed: 2012 Project co-funded by the University of Agder

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Off shore wind park control assessment methodologies to assure robustness and fault-tolerance

With recent years’ development in wind energy capture and an increasing demand for renewable power, the amount of wind turbines deployed in each wind park(WP) has increased. More wind turbines equal more power, but not without new challenges. Traditional load-fl ow and transient analysis is done, but an in-depth analysis of the interaction between control systems and their robustness is not completed.

The project seeks to generate specifi cations for control systems and models to assess the quality of the system supplied. An increase in complexity results in more untested control system interaction. WPs are tested for grid code compliance, but statistical testing methods could be included as well. Challenges include determining the level of detail for the assessment and generic modelling of components.

The perspective is to complement the normally used harmonic analysis with theory from the fi eld of robust control and gain a more secure platform for expansion of WPs.

Mikkel Peter Sidoroff Gryning To be completed: 2015 Dong Energy, Industrial PhD

Modular robotic playware

The current modular robot fi eld has still many control engineering challenges to face. This is why this project will implement adaptive control theory on a modular robotic system. This will allow us to regulate the system regardless of its confi guration, shape or weight (e.g., static stability, dynamic stability, steady speed output); it will focus as well on the inclusion of interactive technologies and on the development of its mechanical design.

During the project, an interdisciplinary approach will be utilized during the working method which will start off from mechanical design engineering in combination with control engineering, coupled with an understanding of play dynamics and human motivation.

The PhD project will provide novel insights on controller implementations in modular systems. The results are expected to aff ect concept developments for future products on the global market, which exploit modular playware technology.

To be completed: 2015

Moises Pacheco Co-funded by the Danish Advanced Technology Foundation

Modular platform for commercial mobile robots

Developing a robot application for sale on the commercial market creates a lot of new challenges. Such a robot is a very complex system, and yet it must be cost-effi cient to develop and produce, and reliable and safe enough for people to actually use. Mobile robots already exist as successful commercial products, like lawnmowers, vacuum cleaners and for transportation. But the potential is much higher.

By using higher level models to describe the robot system, the project strives to improve the ability to reuse functionality across diff erent robot systems and avoid having to invent everything from scratch every time. Additionally, the project focuses on developing methods for automatic calibration, optimization and supervision of the parameters for the robot to improve reliability and safety.

The vision of the project is to close the gap between what is possible to do with robots in a research lab, and what a company like Prevas A/S can develop for the commercial market.

To be completed: 2013

Morten Kjærgaard Prevas A/S, Industrial PhD

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Performance monitoring, diagnosis and advanced control of bio-refi nery Bioethanol is thought to become one of the primary liquid fuels, and extensive endeavours have been conducted to make the production process feasible on a large scale. In this context, DONG Energy has built a large second generation bio-refi nery in Kalundborg, Denmark, also known as the Inbicon demonstration plant. The bio-refi nery converts agricultural wastes into bioethanol utilizing only steam and enzymes, therefore categorizing the technology as a green process. First, the biomass is pretreated in a pressurized thermal reactor in order to expose the cellulose. After- wards, an enzymatic liquefaction process occurs and the fi bres are prepared for fermentation. Bioethanol is produced during fermentation and is recovered with the help of distillation columns. Two other by-products are produced, i.e. C5 molasses, a syrup used to feed farm animals, and bio-pallets, which are burnt in a power plant.

The fi rst objective of the PhD project is to model a large scale second generation bio-refi nery. Afterwards, monitoring and fault-diagnosis tools will be developed by investigating each individual unit of the process. Special performance cost functions will be derived for each sub process and also for the overall bio-refi nery. The last goal involves L1 adaptive control, which represents the latest novelty in control theory. Controlling the bio-refi nery with L1 adaptive controllers has never been attempted before, and this issue will be investigated in the end. Remus Mihail Prunescu To be completed: 2015

Dong Energy, Industrial PhD

Interactive modular playware and play dynamics

When playing we enter a special, therapeutical and enjoyable mental state that draws us away from our ordinary lives. Entertainment products have become better and better at getting its users to effi ciently enter into this state both mentally and physically. The project will continue this development and focus on understanding how to move users into a state of play through interaction with tangible products.

This project will work towards creating such an understanding through the development of the modular playware technology project, which, together with LEGO and Advance, uses intelligent hardware and software that stimulate playful activities in order to develop the intelligent LEGO brick of the future.

It will be the objective of this project to explore and implement a variety of game mechanics in the modular playware platform in a way that allows the player(s) to interact and manipulate with the game-play and customize it to their individual play-scenario. In addition, the project will work towards creating a new design methodology for evaluating user studies with regard to how well the product gets its player(s) into the state of play. This should be an important contribution to the research fi eld of entertainment products, as no such evaluation method exists today. Rune Fogh To be completed: 2015

Co-funded by the Danish Advanced Technology Foundation

Fault diagnosis and fault Handling for autonomous airplanes

Small unmanned aerial vehicles have a great potential in many diff erent applications. However the relative simple components and control methods often used on this type of aircraft can be the cause of dangerous crashes. Safety and reliability considerations used on piloted airplanes cannot directly be used on smaller unmanned airplanes because of weight and space limitations, and therefore other methods must be considered.

This project investigates diagnosis of sensor and actuator faults for unmanned aerial vehicles. The goal is to create a system that is able to diagnose faults by analysing telemetry data while in the air. The airplane operator is notifi ed when a fault is discovered, and depending on the severity of the fault, appropriate actions are taken autonomously or suggested to the operator to bring down the plane in a safe manner and avoid hazardous situations.

Adding diagnosis systems to small unmanned aerial vehicles will make them able to complete their mission in a safer and more effi cient way and thereby enhancing their usability.

Completed: 2012

Søren Hansen Project co-funded by the Royal Danish Navy

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Sensor-Based real-time control of robots

While robots are being used extensively in production of uniform objects, they are hardly present when it comes to handling products with varying size and form like vegetables and animal products. The variation makes offl ine planning of the handling procedure impossible, and so far it has not been possible to use robots without compromising speed and robustness, thus making an automated solution infeasible compared to human workers.

This project aims to overcome this obstacle by combining input from several diff erent sensors to get fast and dependable control of a robot arm. Development of generic sensor-based methods for seamless switches between free cruising, approach towards, and contact with the object will be part of the project. In addition, the feedback from the sensors will be used to verify correct operation to ensure robustness.

The results are expected to benefi t production companies by making it possible to utilise robots for handling varying products and small batches.

Thomas Timm Andersen To be completed: 2015 Co-funded by the Ministry for Science, Innovation and Higher Education

Performance assessment and system monitoring for refrigeration systems

Supermarket refrigeration plants consume a large amount of energy. Consequently, it is benefi cial to operate the systems in the best possible way. However, optimal operation of a refrigeration plant is also dependent on other costs such as the replacement of components due to excessive wear. Thus, assessing the performance of the refrigeration plant is important to ensure optimal operation with respect to the total cost of ownership.

This project examines the possibility of establishing a performance measure for refrigeration systems including the control system. The development of algorithms to actively assess the performance of a distributed control system will be part of the project. In addition, automatic accommodation for the cause of the performance degradation of a control system by means of online retuning and/or redesign will be addressed.

The project focuses on the development of methods and tools for active performance assessment of refrigeration systems and algorithms for accommodation of performance degradation.

Completed: 2012

Torben Green Danfoss A/S, industrial PhD

Consequence reasoning in multilevel fl ow modelling and its applications

Prognostics or consequence analysis are essential to industries for evaluation of system conditions during operation. It focuses on predicting future events when anomaly happens and the system will no longer perform its intended function to fulfi ll its design goals. The result of consequence analysis must be meaningful, reliable, and actionable to make sense and communicate with operators. With modern engineering system and industry infrastructures, complex automation systems are adopted, and quantitative dynamic models are explored to describe system behaviour. However, on top of that, consequence analysis is also a highly functional-oriented task. Analyse the consequence propagation on the goal-function level is therefore a useful approach to help the operator interpret the system behaviour.

The aim of this project is to develop principles for consequence reasoning for a functional modelling methodology, namely Multilevel Flow Modelling (MFM). Design of a dynamic consequence analysis tool based on MFM is also part of the project scope. This tool should be able to facilitate the operation supervision system as risk monitor, and provides meaningful prediction of the system behaviour.

Xinxin Zhang To be completed: 2015

Co-funded by the Institute for Energy Technology, Halden, Norway

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Head of group: Professor Jens E. Wilhjelm

he group is responsible for the BSc and MSc programs in Medicine and Technology and conducts Tresearch within diagnostic ultrasound imaging, magnetic resonance imaging (MRI), hyperpolarization in MRI, biomedical signal processing, cellular signalling, neural stimulation, biomechanics and educational soft ware.

Th e educational programs in Medicine & Technology are jointly oﬀ ered by DTU and Faculty of Health Sciences, University of Copenhagen (KU), in close collaboration with the Department of Clinical Physiology and Nuclear Medicine and PET at Copenhagen University Hospital (Rigshospitalet).

In 2012, the BSc program attracted the highest number of total applicants at DTU and had the highest admission grade among engineering educations in Denmark. More than 350 students attend the two programs ensuring a high number of qualiﬁ ed students for PhD projects (about 25 PhD projects are currently under way) and a high innovation potential.

A particularly proud moment was when Th e Gunther Laukien Prize 2012 was awarded to Jan Henrik Ardenkjær-Larsen, Adjunct Professor, for his seminal contribution to hyperpolarized magnetic resonance. Moreover, among international experts our eﬀ orts in diagnostic ultrasound are characterized as being daringly ambitious and a considerable success.

Our Center for Fast Ultrasound Imaging (CFU) maintains its leading position in creating new ultrasound imaging methods for improved diagnostic eﬃ cacy and expanded clinical use. Th e research spans from development of novel transducer architectures to pre-clinical trials and includes e.g. development of the research system SARUS, devising new synthetic aperture imaging schemes and optimizing the methods for clinical use.

CFU has developed the transverse oscillation vector velocity blood ﬂ ow imaging technique, now implemented by our collaborator BK Medical and FDA approved for sale in early 2012, thus being the ﬁ rst on the world market. Th e approach has also been further developed for three-dimensional estimation. BIOMEDICAL ENGINEERING BIOMEDICAL

In December 2012 we received a grant from the Danish Advanced Technology Foundation of 75m DKK for the development of new intuitive ultrasound scanners. Th e project will radically improve the application possibilities of ultrasound by rethinking the technologies. Th e project has a combined budget of 152m DKK including our partners BK Medical, DTU Nanotech, Rigshospitalet, Meggitt A/S and the Alexandra Institute.

Our Magnetic Resonance (MR) group is expanding and broadening its focus. Th is includes fundamental research on the hyperpolarisation of biologically relevant molecules. When combined with MR imaging, the >10.000-fold signal enhancement provided by the hyperpolarisation process may allow doctors to non- invasively follow biochemical pathways involved in e.g. cancer, diabetes and cardiovascular diseases. Th ere is close collaboration with GE Healthcare, the Danish Research Centre for Magnetic Resonance at Hvidovre hospital (DRCMR), Rigshospitalet and Skejby Hospital on the medical applications of the method.

In another new research area – Integrative Neuroimaging – MR imaging has proven very successful in the diagnosis of neurological diseases and in brain research. To counteract some intrinsic weaknesses, the new research ﬁ eld will complement MRI with techniques such as electroencephalography or transcranial magnetic stimulation (TMS) to combine their mutual strengths. Th e research is carried out in collaboration with DRCMR, Max- Planck-Institute for Biological Cybernetics (Germany) and others.

Within Biomedical Signal Processing we specialize in multimodal recording of signals from humans for monitoring and detection of epileptic seizures, heart diseases and early detection of neurodegenerative diseases (Parkinson, narcolepsy, Alzheimer, dementia, schizophrenia). Th e main collaboration partners are Rigshospitalet, Glostrup University Hospital, the Epilepsy Hospital Filadelﬁ a, Svendborg Hospital, KU, HypoSafe A/S, Lundbeck A/S and DELTA. We also conduct research on wearable biomedical systems and brain-computer interface (BCI) technology for old-aged and disabled people.

Other research activities are carried out in orthopaedic and cardiovascular biomechanics in collaboration with DTU Mechanics and Hvidovre Hospital.

In Cellular Information Processing the objective is to uncover the basis of selected cellular signalling processes and use this knowledge to understand and control collective cellular behaviour. Th is involves describing the molecular basis for protein signalling, binding and aggregation, which is at the heart of bacterial bioﬁ lm formation and protein misfolding diseases. Th e work is done in collaboration with Cambridge University, KU and DTU.

Experimental and theorectical investigation of signaling in quorum sensing of pseudomonas aeruginosa

The main focus of this PhD project is on the detection of signal molecules used by bacteria to regulate collective behaviour and on the binding of these molecules to regulator proteins. When a threshold value for the signal molecule concentration is reached the bacterial cells change from harmless individual behaviour to collective behaviour which can be fatal to the host organism.

So far, research has demonstrated that it is possible to detect these important signal molecules using Surface Enhanced Raman Scattering (SERS) at nano-molar concentrations and physiological conditions. Further, a bioassay using a fl uorescence technique has been carried out and the order of the regulator activation process established. These important results fuel the design of inhibitors of the collective behaviour and of cures of infections that are tolerant to antibiotics.

To be completed: 2013

Anetta Clausen Project co-funded by Radiometer

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Optimal low power microelectronic implementation for single-use ECG arrhythmia detection device

The development of new single-use wireless devices for home based physiological monitoring is expected to signifi cantly improve diagnostics and treatment of diff erent potential life-threatening heart disorders. This can be accomplished by developing a robust device platform with an ability to record and automatically analyze and classify the electrical signals from the heart.

The aim of this research project is to investigate new robust and power effi cient algorithms for automatic detection of heart beats and classifi cation of each beat into diff erent critical arrhythmias and normal beats. The developed signal processing algorithms will be implemented in microelectronics that can be integrated with the wireless ePatch ECG sensor system developed by DELTA.

The project will result in the development of a research prototype of a single-use ECG arrhythmia detection device that can automatically distinguish between normal and abnormal heart rhythms.

Dorthe Bodholt Saadi To be completed: 2014 Project co-funded by DELTA

A novel MR contrast agent for angiography and perfusion: Hyperpolarized water

Magnetic Resonance Imaging (MRI) is the preferred imaging technique for a number of medical conditions. However, the present technology has its limitations in resolution and signal-to-noise ratio (SNR). Furthermore, the applied contrast agents incorporate substances with potentially severe side eff ects. Hyperpolarized compounds have proven to enhance the MR signal by several orders of magnitude.

The aim of this project is to demonstrate that hyperpolarized water can be applied as a contrast agent, and to develop and optimize the procedures involved. Challenges include maximizing polarization, quenching of the radical in the dissolution of the solid sample into an injectable formulation and optimizing the imaging sequences to exploit the hyperpolarized signal for best possible contrast and SNR.

The increased MR signal obtained with hyperpolarized water enables coronary angiography within a single cardiac cycle; something which is not currently possible with MR.

To be completed: 2015

Hans Kasper Wigh Lipsø Project co-funded by The Danish Agency for Science, Technology and Innovation

Detection of epileptic seizures with automatic signal processing based on movement based data

Today 25% of the patients suff ering from epilepsy cannot get free of seizures. The unawareness of when the next seizure sets in makes the patient very insecure. As the seizures mostly appear without premonition, the patients are unable to bring themselves to safety. An alarm system able to detect epileptic seizures would therefore be of great help. Whenever a seizure sets in, the patient could immediately get help from family or hospital staff .

The objective is to design medical signal processing algorithms that are able to distinguish between epileptic seizures and normal movements. These algorithms should be developed based on movement data (e.g. from Electromyography (EMG)). The alarm system is thereby proposed to be a system based on recordings of movement data making the seizure detection more reliable and comfortable for the patients.

The fi nal algorithm is to be implemented in a small EMG device and tested in the clinics. Secondarily the study may provide new information on the diff erent seizure types.

Isa Conradsen Completed: 2012

Project co-funded by the Danish Epilepsy Centre and the Peter & Jytte Wolf Foundation for Epilepsy

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Imaging of in-vivo pressure using ultrasound

Mapping pressure fi elds in hemodynamic fl ow patterns will help physicians in the process of managing a wide range of cardiovascular diseases, e.g. atherosclerosis.

Today, pressure fi elds are mapped by means of catheters inserted into the blood vessel. This procedure, however, requires that the patient will be exposed to ionizing radiation for the positioning of the catheter. Furthermore, the catheter itself causes inconvenient disturbances to the actual pressure fi eld, which the physician is trying to map. Being able to map pressure fi elds without having to insert catheters into the blood vessel or using ionizing radiation would have great clinical value.

The purpose of this project is therefore to develop a technique for mapping the pressure fi elds inside the blood vessel, non-invasive. This can hopefully be achieved by non-invasive studies on the behaviour of fl uid fl ow, which is obtainable through modern ultrasound scanners.

The perspective is to provide a non-invasive tool for the physician that can map the hemodynamic pressure fi elds, Jacob Bjerring Olsen leaving no reason for exposing the patients to ionizing radiation. To be completed: 2015

Project co-funded by the Danish Advanced Technology Foundation and Radiometer

Early diagnosis of neurodegenerative diseases

Research has provided a unique insight into mechanisms, which regulate sleep and wakefulness, including the neurotransmitters. Certain diseases related to sleep express the early manifestations of other more serious diseases and establish a window for understanding fundamental disease processes. REM sleep behaviour syndrome is an early manifestation of developing severe neurodegenerative diseases. In Parkinsonism and similar diseases, there is a destruction of the brain’s basic structures years before actual disease manifestations are evident. Once the disease is manifested, the possibility of treatment is limited. Early disease recognition is important as it allows an early intervention.

This project addresses some of the earliest disease manifestations in the brain stem and hypothalamus focusing on Parkinsonism and dementia. The project’s aim is to achieve better diagnosis and early disease insights into the mechanisms leading to destruction of the brain’s basic functions.

Design of methods for automatic signal description and signal interpretation of the micro-and macro-structural changes occurring in waking and sleep electroencephalogram will form a basis for increased understanding and will Jacob Kempfner provide the opportunity for earlier intervention.

To be completed: 2013

Project co-funded by Glostrup Hospital & Radiometer

Synthetic aperture compound imaging

Medical ultrasound imaging is used for many purposes, e.g. for localizing and classifying cysts and tumors. A major drawback of ultrasound imaging is the low contrast due to the presence of speckle artifacts. A successful approach to remedy this is spatial compounding, where images are acquired from diff erent directions and combined. The resulting images have a reduced speckle appearance, but at the cost of a reduced frame rate.

This project develops methods to perform spatial compounding using synthetic aperture data acquired with the experimental ultrasound scanner SARUS. It is investigated how to obtain a reduction in speckle appearance without a reduction in frame rate. The methods are evaluated through phantom studies and in pre-clinical trials.

The perspective is that synthetic aperture compounding will be able to obtain high contrast images allowing for an early detection of cysts and tumors.

To be completed: 2012

Project co-funded by the Danish Advanced Technology Foundation and BK Medical Jens Munk Hansen

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Non-linear synthetic aperture imaging

In contrast to regular ultrasound B-mode imaging where resolution varies with image depth, synthetic aperture ultrasound imaging allows for images with high resolution throughout the entire image. While imaging of small objects especially in the regions around the rib cage can be diffi cult using regular ultrasound imaging, non-linear imaging can benefi t from a narrower beam width and produce images with high resolution and contrast.

The objective is to create an improved ultrasound imaging method by combining synthetic aperture imaging with nonlinear ultrasound imaging to provide images with high resolution and high contrast without losing frame rate by exploiting the advantages in both techniques.

This new imaging method will be implemented on the Synthetic Aperture Real Time Ultrasound Scanner (SARUS) and on commercially available ultrasound systems for pre-clinical trials conducted in cooperation with medical doctors from Copenhagen University Hospital, Rigshospitalet.

To be completed: 2013

Joachim Rasmussen Project co-funded by BK Medical and the Danish Advanced Technology Foundation

Prediction and detection of epileptic seizures

Of the world’s population, 1% suff ers from epilepsy. Most of these patients can be treated out of their reoccurring seizures with existing medication or epilepsy surgery, but approximately 25% will continue to have epileptic attacks. These unforeseen seizures stigmatizes the patients and cause considerable demoralization, frustration and anxiety for themselves as well as family and friends.

Using the electrical signals from the brain, we look at the possibility of detecting, and perhaps even predicting, seizures. Instead of measuring at a hospital, we have developed a small portable device following the patient in daily life. The challenge is now to develop a dedicated seizure detection algorithm that can automatically detect the seizures so that the doctors do not have to spend hours on manual evaluation of the recordings.

In 2011 the fi rst ambulant trials with absence epilepsy started. Design and test of an algorithm for this patient group is followed by additional work related to other patient groups.

Completed: 2012

Jonas Duun-Henriksen HypoSafe A/S, Industrial PhD

Characterization of early and mature electrophysiological biomarkers for Alzheimer’s disease and Parkinson’s disease

Neurodegenerative diseases are highly debilitating with serious detrimental impact on work, social and family life. The progressive loss of neurons leads to severe morbidity and even death. Most of the diseases have no cure, and the goal of treatment is to improve symptoms, relieve pain and increase mobility. The discovery of early markers can present opportunities for earlier intervention, and hence, have a signifi cant impact on the patient outcome.

Employing appropriate biomedical signal analysis algorithms, early disease identifi cation is in this project aimed to rely on analysis of electrical signals from the brain (EEG).

Associated and simultaneously recorded electrophysiological modalities will be included in the analyses to characterize patients with Parkinson’s disease and Alzheimer’s disease at early and mature stages of disease progression relative to healthy volunteers.

By characterizing and combining diff erent electrophysiological biomarkers refl ecting diff erent aspects of the brain, it Julie Anja Engelhard Christensen is expected to improve the precision, sensitivity and specifi city of the early disease identifi cation.

To be completed: 2014

Project co-funded by Glostrup Hospital and H. Lundbeck A/S

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Motion-insensitive magnetic resonance imaging

Medical magnetic resonance imaging and spectroscopy (MRI, MRS) are clinical scanning techniques widely used for visualisation of soft tissue. MRI and MRS are hampered by severe motion sensitivity, which causes ineffi cient scanning, errors in images, and safety concerns at high magnetic fi eld. The problem has been partially solved using new motion tracking techniques to make the imaging slices follow the patient.

The accompanying electromagnetic fi eld changes have not been compensated, however, which is the aim of the current project. Motion will be tracked during scanning (e.g. video-based), and the scanner settings will be optimized real-time for every new position. The project is of signifi cant value for ultra-high fi eld imaging and will therefore be implemented on the new national 7T MR scanner, which will be located at Hvidovre Hospital.

Reduced motion sensitivity can improve clinical MRI, especially for patient groups that often cannot lay still, e.g. children, patients in pain, and confused patients.

To be completed: 2015

Mads Andersen Project co-funded by Hvidovre Hospital, Radiometer Medical and the Danish Agency for Science, Technology and Innovation, Industrial PhD

A brain-computer interface (BCI) system for neuro-rehabilitation of ADHD children

Attention-Defi cit/Hyperactivity Disorder (ADHD) is one of the most common psychiatric disorders in children. Conventional treatments, however, off er only incomplete symptom relief for over 33% of ADHD cases. EEG biofeedback has been introduced as a sophisticated basis for highly applicable system known as the brain-computer interface (BCI). BCI bears great potentials for rehabilitation, such as augmenting human cognitive or motor functions.

The objective of this project is to train a BCI model by using EEG data recorded during subject’s training so as to achieve a good attention performance. This will include the optimization of the BCI scheme and testing its feasibility in healthy controls and children with ADHD. The subject modulates his/her own brain activities to make the BCI system classify the EEG signals based on neuro feedback principle during the training.

An effi cient BCI scheme not only would be a promising way to improve the life of ADHD subjects, but also could be extended in treatment of other types of mental disabilities.

To be completed: 2015

Mehdi Ordikhani-Seyedlar Project co-funded by Hvidovre Hospital, Radiometer and the Lundbeck Foundation

Micromachined integrated transducers for ultrasound imaging

Currently ultrasound images are made using 1D or 2D arrays of piezoelectric transducers. The geometry is dictated by the frequency and the dimensions for the transducer elements are on the order of 250x250 μm or smaller. With the increasing demand for higher frequencies the dimensions become smaller and the elements become more diffi cult to fabricate. This results in reduced image quality when the arrays cannot be made large enough.

The aim of this project is to use standard cleanroom technology to fabricate the new capacitive micromachined ultrasonic transducers (CMUT). CMUT elements can be fabricated very small and connected into large arrays in any kind of confi guration, making high quality ultrasound imaging possible also in 3D. The CMUTs fabricated in this project should be interfaced to the SARUS scanner for real-time experimentation.

Using microfabrication to fabricate capacitive transducers in large 2D arrays will make it possible to produce high quality 3D ultrasound images for medical diagnosis.

To be completed: 2014 Mette Funding la Cour Project co-funded by Radiometer A/S and Department for Micro and Nanotechnology, DTU

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 3D vector fl ow imaging

Medical ultrasound imaging is widely used for studying blood fl ow dynamics in the human circulatory system. However, blood velocity estimates using conventional techniques are angle dependent. This strongly limits the possibility of visualizing complicated fl ow patterns and obtaining the true velocity. This problem has been remedied by methods developed at Center for Fast Ultrasound Imaging (CFU) at DTU Elektro for 2D velocity estimation.

The aim of this project is to develop a method for full 3D vector velocity imaging to correctly show the velocity vector. Methods for acquiring data and estimating the velocity are developed based on 2D techniques already developed at CFU with main focus on the transverse oscillation method. The methods will then be implemented on the experimental ultrasound scanner SARUS at CFU and evaluated on fl ow phantoms and human volunteers.

With 3D vector fl ow imaging, complex fl ow patterns can be visualized and, potentially, pathological fl ow patterns around occlusions, valves, and bifurcations can be identifi ed.

Completed: 2012

Michael Johannes Pihl Project co-funded by the Danish Advanced Technology Foundation

Two stage beam forming methods for 3D imaging

In conventional ultrasound imaging, sound is emitted in one direction at a time. That implies sequential image acquisition limited by the speed of sound. This makes it very diffi cult to acquire 3D images fast and makes it impossible to acquire a full volume of data for blood fl ow in the heart. A radical break within this area has been synthetic aperture imaging (SAI), where ultrasound is emitted in all directions and the volume of data is reconstructed through focusing afterwards.

The aim of this project is fi rst to show that SA 3D imaging can be done, and to compare it with conventional ultrasound imaging. However, because of the vast amount of calculations and data throughput, SAI has very high hardware requirements.

The end goal of this project is to utilize the 2D two stage beamforming technique and apply it to 3D imaging. Subsequently, it has to be investigated whether two stage beamforming is the optimal way of doing 3D imaging, or if there are other clever ways to image a 3D volume.

Morten Fischer Rasmussen To be completed: 2014 Project co-funded by the Danish Advanced Technology Foundation and BK Medical

Pre-clinical and clinical studies of synthetic aperture and vector fl ow imaging

Description

The purpose of this research project is to do pre-clinical and clinical studies of new digital techniques to improve image quality and frame-rate in ultrasound scanning.

The recorded pictures are evaluated in terms of resolution, contrast, depth, noise, frame-rate and artefacts.

Other clinical studies will investigate techniques for 3D imaging of blood fl ow and improving the visualization of blood fl ow in e.g. arteriosclerotic blood vessels.

To be completed: 2014

Project funded by Rigshospitalet, Copenhagen University Hospital

Peter Møller Hansen

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Long timescale simulations of proteins

Many proteins are highly dynamic and adopt diff erent states under physiological conditions. These conformational isomers hold the key to understand important biological processes (enzymatic catalysis, signal transduction, regulation and protein misfolding).

The overall aim of the project is to develop a general computational method to elucidate the molecular mechanism of conformational switches. At the heart of the project is the use of a novel probabilistic method, developed in our group, that overcomes some of the defi ciencies of current methodologies to protein dynamics. Our results were corroborated against Nuclear Magnetic Resonance data, and discrepancies used to refi ne the force fi eld.

The method will be applied to understand fundamental mechanisms in enzymatic catalysis, and to identify the conformational states that trigger the protein aggregation process associated with misfolding diseases, such as Alzheimers, Parkinsons and type II diabetes.

Completed: 2012

Sandro Bottaro Project co-funded by Radiometer

Diagnosis of heel pad injuries

The project seeks to gain in-depth understanding of the mechanical changes that arise in mechanically damaged heel pad tissue. Heel pad injuries, caused by fall accidents, marathon running, falanga torture etc., may cause the destruction of the heel pad intricate septation, a severe condition where the shock absorbing feature of the heel is lost, causing great pain for the patient, when trying to walk.

The objective of the project is to develop quantitative methods for diagnosing such injuries and to gather information on the complete deformation of the heel pad tissue. The heel pad modeling will be based on MRI, ultrasound and clinical measurements on the mechanical properties of heel pad tissue.

The quantitative validated mechanical examination methods will constitute pre-requisites for diagnosis and cure of heel pad diseases as well as medico-legal assessment for falanga torture.

Completed: 2012

Project co-funded by Radiometer Sara Matteoli

Synthetic aperture fl ow imaging using a dual beamformer approach

Blood fl ow imaging using synthetic aperture (SA) has many advantages compared to conventional ultrasound imaging as data can be acquired continuously for the full imaging region. The accuracy of estimates can therefore be very high and the frame rate can be increased because of the continuous data acquisition. It is also possible to fi nd the velocity in all directions and map out complex fl ow phenomena.

However, SA fl ow imaging requires a large number of calculations to be performed, which is a challenge for the current system. The aim of this project is to develop a computationally effi cient method for synthetic aperture velocity estimation based on a dual beamformer approach. The challenge is to lower the number of emissions and still maintain the quality suffi cient for fl ow estimation.

Commercial implementation of a full SA ultrasound scanner capable of both anatomic and fl ow imaging, thus increasing the diagnostic value of ultrasound imaging by a higher accuracy and frame rate of velocity estimation systems.

Completed: 2012 Ye Li Project co-funded by the Danish Advanced Technology Foundation and BK Medical

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Head of Center: Professor Jacob Østergaard Deputy Head of Center: Associate Professor Joachim Holbøll

he Center for Electric Power and Energy (CEE) was established 15 August 2012 as a merger of the Tformer Center for Electric Technology (CET) and the group Intelligent Energy System (IES). Th e IES group originates from the former Risø National Laboratory of Sustainable Energy.

Th e center is located at both Risø and Lyngby Campus and has a staﬀ of approximately 85 including PhD students and is thereby one of Europe’s largest groups within its ﬁ eld. Th e center will act as a central collaboration interface for the energy industry.

Th e center is involved in research, education and innovation with competences within and focus on technical solutions enabling transformation of the electric energy system into a sustainable, economic and reliable system, which includes: • Electric Components: analyses, modeling, design and development of electric components • Energy Resources: distributed energy resource technologies and their properties, mutual coordination, grid integration and services • Energy Systems, Operation and Management: analyses, modeling and development of solutions for management and operation of future active power distribution systems • Electric Power Systems: power system engineering and impact from large scale integration of renewable energy sources on power system stability, security and reliability • Electricity Markets: design of electricity markets and socio-economic optimization methods for market analysis and design

Examples of cutting edge research results in 2012 include: • CEE leads the largest Danish smart grid project, iPower, which bring together 32 academic and industrial partners. Research results regarding intelligent control of decentralized power consumption and production are transformed into new innovative solutions, which enable management of millions of ﬂ exible consumption units in a smart grid. • Research in electricity markets with a high share of stochastic power production and demand response based on a smart grid infrastructure. Th ese research endeavors make the best use of state- of-the-art mathematical programming techniques such as stochastic programming, hierarchical optimization and robust optimization, the results of which have been published in top journals. One of the developed concepts, control-by-markets, has been the basis for one of the largest EU-funded projects to date focusing on a single Smart Grid concept development (EcoGrid EU). • Research in methods for fast real-time stability and security assessment utilizing PMU-measurements. Based on an element-wise assessment approaches into a normalized injection impedance plane, innovative aperiodic small signal instability detection and blackout early-warning methods have been developed. Use of state-of-the-art sparse matrix LU-factorization algorithms and graph-reduction algorithms contribute to a very fast detection (milliseconds). Several of the research results are now published, patented and under further development in collaboration with ETH Zurich, Siemens and others. • Research in autonomous voltage and frequency services from demand, which has led to development, implementation and large-scale demonstration of demand technologies supplying frequency controlled reserve with a strong business potential. Th e European transmission system operators have in a newly released draft grid code just adopted the developed technology and thereby opened a path for deployment. CENTER FOR ELECTRIC POWER AND ENERGY AND ENERGY POWER ELECTRIC FOR CENTER • Research and development in superconducting wind turbine generators with possible application in future very large wind turbines (≥10 MW) and superconducting electrical machines in general. Th e research is based on strong competences within electric machines and extensive experiences with superconductivity. • Research in ancillary services from wind power plants. Research results within frequency control and power system oscillation damping have recently been published, patented and adapted by two world-leading wind turbine manufactures, Siemens and Vestas.

Our center plays a major role in PowerLabDK, our new experimental platform for electric power and energy. Th e platform includes world-class laboratory facilities at DTUs Lyngby -, Risø - and Ballerup Campus and the Bornholm power system owned by Bornholm’s energy supplier, Østkraft . First phase of PowerLabDK has been completed and the platform was inaugurated in March 2012. PowerLabDK is implemented in close collaboration companies and organizations. Since the inauguration the laboratories has attracted a lot of attention from governments, industries and academia world-wide. Th e experimental facilities in PowerLabDK have been the basis for many collaboration activities, external users as well as empiric based research.

For instance new research results have been obtained utilizing the real-time digital simulator (RTDS) facility at Lyngby Campus and proof-of-concept has been obtained for several diﬀ erent technologies in the SYSLAB and PowerFlexHouse facilities at Risø Campus. Results based on the hardware-in-loop simulations in the RTDS includes development of active distribution grid controllers, directional overcurrent protection for wind farms and VSC HVDC connection of oﬀ shore wind power plants.

In 2012 more than 1,000 households on Bornholm were enrolled in the large-scale experiment of the future smart grid in the EcoGrid EU project. By means of ﬂ exible consumption, the project will show how Europe’s electricity system can manage over 50 % wind power and other ﬂ uctuating and less predictable renewable sources. DTU Elektro leads the development of the architecture and market-based solutions in the project. In 2012 the project was awarded as the world’s best sustainable IT-project by the Sustainia organization.

Our results, which in 2012 have been reported in approximately 100 scientiﬁ c publications, have been obtained in close collaboration with the many academic and industrial partners of CEE and within the frames of CEE’s strategic partnerships with Energinet.dk, DONG Energy and Siemens Wind Power.

CEE is represented in a number of international forums, including International Smart Grid Action Network of the International Energy Agency (IEA ISGAN), Association of European Distributed Energy Resources Laboratories (DERlab) and IEEE Power and Energy Society. In 2012 the Danish Smart Grid research network has made a roadmap under leadership of DTU Elektro.

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Energy storage and energy system integration

Energy storage plays a key role when penetration of fl uctuating renewable electricity reaches a high level. The benefi ts associated with energy storage in such a scenario reside in its ability to act as energy buff er. Energy storage can accommodate excess renewable production and store it for a later use, ensuring a continuous supply of renewable electricity.

This PhD project aims to investigate diff erent options for coupling the power generation system with other components of the energy system, in order to exploit their energy storage capabilities and associated benefi ts. Energy storage applications embrace a large variety of fi elds among which: the electrifi cation of the heating systems, the integration of electric vehicles in the electric grid, and operation of energy systems under variable electricity prices.

A better understanding of energy storage and its interaction with energy systems are crucial for fostering renewable energy technologies.

To be completed: 2014

Alessandro Pensini Project co-funded by EcoGridEU

Electric vehicle integration in a real-time market

As opposed to the hourly spot-price market of today, the proposed real-time market of the EcoGrid EU project will see price updates as often as every couple of minutes. To allow the individual resources to react to these changes independently, so called “smart controllers” are needed. In order for this market to work, however, the proper ICT platform has to be developed.

The focus of this PhD project is on the ICT platform required for successful EV integration, not only into the existing market platforms but with special emphasis on the proposed real-time markets of the future. As the move is made towards even more distributed energy resources, existing standards will have to be refi ned and new ones developed, in order to allow electric vehicles to participate directly in these markets.

Results obtained during the PhD project, will contribute to EDISON project, as well as carry those experiences further to the EcoGrid EU project, where the main focus will be.

To be completed: 2014

Anders Bro Pedersen Project co-funded by EcoGridEU and the Trane Foundation

Methods for enabling utilisation of the potential fl exibility in power production and consumption of entities connected in the low voltage network in a virtual power plants framework

With an increasing penetration of wind power in the Danish national grid means of generation control is gradually reduced. Thus if we want to keep stability in the power system methods for fl exible consumption have to be developed. This project investigates means of local energy management in households, using the thermal mass of a building as unidirectional energy storage. Thereby power consumption for electrical heating can be postponed or precipitated on an hourly timescale if needed. Also other types of units, e.g. solar generation and EV charging, will be considered. The units will be aggregated to form a single unit in Power Hub, an implementation of a virtual power plant developed by DONG Energy.

In the future households should be active players in the coming smart grid and use fl exible power consumption to maintain stability in a power system with a high share of volatile production.

To be completed: 2013 Anders Thavlov Project co-funded by DONG Energy

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Compatibility of electrical main components in wind turbines

An electric network is a complex system of interconnected components. Following a specifi c occurrence in the network the result of interaction between the components may be harmful to them and thus to the entire system. The interaction of such components as transformers, cables and breakers subjected to electromagnetic transients is an important subject of ongoing studies.

The objective of the project is to defi ne the concept of electrical compatibility by defi ning the proper interactions of electric components for all feasible situations in a wind farm’s operation. In order to identify risky combinations of components, a large number of simulations have to be conducted under systematic parameter variation. This is only possible with comparable short calculation times, which means that an important part of the project must be the defi nition of a necessary and suffi cient level of details in the component specifi cations.

Finally, the project will be concluded by presenting guidelines and recommendations for electrical components for wind turbines according to developed compatibility rules. In this way, the risk of critical component combination can be reduced already at an early stage of a wind farm design. Andrzej Holdyk To be completed: 2013

Project co-funded by ForskEl and Energinet.dk

Lightning protection of fl ap system for wind turbine blades

Wind turbines are especially vulnerable to lightning strikes due to their height and location in open spaces, and the blades are the most exposed components. It has been experienced that on average wind turbine blades receive several lightning strikes during their life time, even if they are made purely of insulating materials, and the damages can be severe. The tendency of more sensoring and control equipment inside the blade contributes to the need of reliable lightning protection systems to be provided.

The aim of this PhD project is to investigate the direct and indirect eff ects of lightning discharges in connection with Controllable Rubber Trailing Edge Flaps (CRTEF) of wind turbine blades. The study comprises the analysis of the discharge attachment and the current transmission, as well as the eff ects of the induced electromagnetic fi elds, plus the effi ciency of possible protection systems to be applied. The main tools for this analysis are the simulation by the fi nite elements method and testing in the high voltage laboratory.

The results of both simulation and testing will be the base to design an eff ective and reliable lightning protection for the CRTEF and related systems. Anna Candela Garolera To be completed: 2014

Project co-funded by EUDP/Danish Energy Agency

Market design and network planning for active distribution grid

The common use of demand response, electric storage and an increment penetration of distributed generation (DG) based on renewable energy resources into existing distribution network brings high complexity of system operation and network planning. It also leads to many issues regarding new market design, regulation, congestion, reliability and etc. The conventional passive network management is not suitable in the new environment, which need to be changed into active network management. Active management of distribution network enables the distribution system operator (DSO) to dispatch network in an integrated effi cient manner. The objective of the PhD project is to propose a DSO market design for active distribution grid, which can motivate the effi cient utilization of demand response and DG and reduce electricity price for end customers. The objective also includes the development of incentive market mechanism, which can mitigate the daily peak load and motivate grid upgrade for ensuring suffi cient capacity.

The results of this project will contribute to develop a robust market design for active distribution grid, which will be the basic frame of normal operation. Moreover the necessary emergency functionalities needed in situations where Chunyu Zhang operation is no longer normal must be developed for maintaining the reliable system operation. To be completed: 2015

Project co-funded by the Danish Agency for Science, Technology and Innovation

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Validation of control services in future sustainable power systems

Electricity in sustainable energy systems is more complex than in conventional systems. Instead of the conventional centrally coordinated control and passive distribution systems, a massive deployment of parallel and distributed control algorithms is envisioned. This new control system will supply the grid with suffi cient control capabilities and resources to balance the uncontrollable in feed of renewable energy.

This project focuses on assessing and developing control algorithms that will be needed in sustainable power systems. Control algorithms for local and aggregated control, based on today’s advanced control strategies including model-predictive and stochastic optimizing control, direct and indirect control concepts will be simulated and tested in PowerLabDK.

The results of this project will contribute to the modernization of the current power system and help paving the way for the sustainable production and consumption of energy.

To be completed: 2015

Daniel Esteban Morales Bondy Project co-funded by the Danish Strategic Platform for Innovation and Research

Policy-based communication for control of distributed power systems

Future power systems will look very diff erent from todays - the most signifi cant change is the increasing number of actively controlled units in the system. The main challenges are scalability, reliability and the fl exibility to include new components and new ways to control these components. Control communication is usually still based on the concepts of measurement and set point; however, communication based on more high-level concepts could bring many benefi ts.

The aim of the project is to investigate the usage of better concepts for communicating, especially the idea of policy based communication, a concept that splits communication up into two separate tasks: The negotiation of future behaviour based on trigger signals, and the activation of the negotiated behaviour with those trigger signals.

Policy based communication could solve a number of problems for Smart Grids, such as the need to deal with unreliable communication, and the need to fl exibly defi ne behaviour.

To be completed: 2013

Daniel Kullmann Project co-funded by Energinet.dk

Electricity market design for distributed energy resources and fl exible demand

Industrialized countries are marching forward to aggressive renewable energy targets, to reduce CO2 emissions and to reduce dependence on imported fossil fuels. The current market framework may not allow these ambitious targets to be met. One aspect in particular, electricity demand, is too rigid for system operators to compensate for fast variations in wind and solar production.

The EcoGrid EU project aims to design a new real-time electricity market and implement it on the Danish island of Bornholm. Electricity prices will be sent to customers every fi ve minutes, allowing them to change their demand and reduce their electricity bill. New market rules, control methods and physical infrastructure will be needed, as well as further understanding of price optimization and system reliability.

Countries will be able to meet their commitments of higher renewable energy integration, while transmission system operators will be able to maintain reliability.

To be completed: 2014

Emil Mahler Larsen Project co-funded by EcoGrid EU

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Early prevention methods for system instability

To provide higher power capacitance, transmission systems should be operated closer to the stability limits. At the same time reliable and uninterruptable power supply should be provided. To meet these requirements there is a need of new real-time stability monitoring methods. Furthermore eff ective method for the instability prevention is required.

This project is aimed on the development of the early prevention method which should help to maintain system stability in real-time utilizing as input data wide area measurements, provided by Phasor Measurement Units (PMU). Early Prevention method is focusing on the fast identifi cation of the most effi cient countermeasure allowing avoiding emerging instability. Specifi cally, application of countermeasures to the load nodes in the grid is considered.

Developed methods will help control room personnel to manage power system safely under stressed operational conditions.

To be completed: 2013

Project co-funded by Energinet.dk Evgeniya Dmitrova

Methods for enabling the exploitation of DERs in supplying power system services

In future parts of or the entire power system ancillary services might be supplied by making use of the potential fl exibility that exists in the consumption of electricity due to inherent energy storage. These so-called Demand Side Resources, DSRs, are electric loads whose power consumption can be shifted without having a big impact on the primary services they are supplying.

The aim of this PhD project is to investigate the capability of the DSR’s, and in general of Distribuited Energy Resources, with respect to moving electric power usage and how they should be controlled by means of a price signal to provide the variation in the aggregate power consumption for supplying regulating power to the electric grid. The project comprises the development of control algorithms for DSRs and defi nition of the setup for simulations and experiments. The proposed setup and control algorithms will be tested and validated in the DTU SYSLAB facility using real electric components such as storage technologies, electric loads and generation units.

To be completed: 2013 Fabrizio Sossan Project co-funded by PSO/ForskEl

Electric vehicles in the electric power system with high penetration of wind power – charge/discharge infrastructure

The recent interest on electric vehicles (EVs) is due to a number of reasons: EVs can provide a unique opportunity to

reduce CO2 emissions; at the same time, EVs can play a major role in energy storage which may facilitate an increased penetration of renewable energies, such as wind power. However, a widespread use of EVs poses new technical challenges concerning their charge/discharge infrastructure.

The objective of the project is to design, develop and test a solution for charging/discharging Electric Vehicles (EVs), with the purpose of smoothing out the eff ect of wind power fl uctuations in the power system. The focus is on the implementation of an effi cient charging architecture for EVs. Furthermore the project will access and develop a vehicle-to-grid concept which can be used for grid power balancing purposes.

An intelligent design of charge/discharge infrastructure is crucial for a widespread utilization of electric vehicles, and

can improve the overall effi ciency of the grid, while reducing CO2.

Francesco Marra To be completed: 2013 Project co-funded by ForskEl and the Edison Consortium

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Demand side optimization via direct load control in smart grids

The change from centralized energy production in large power plants to energy systems with an increasing share of distributed energy resources and asynchronous production requires technologies for implementing responsive demand to network contingencies. In this context, users’ adaptation in future energy systems is a promising technology which this research project is focused on.

This project strives at investigating strategies for direct control of devices at customer side, via probabilistic approaches, dynamic optimization, game theory and run-time scheduling. The design of a system for smart home energy management includes the defi nition of models for appliances, tenants’ behavior and quality of service. The integration and harmonization of diff erent control policies within the same framework are among the most interesting theoretical challenges related to this project.

The available setup in SYSLAB and Power FlexHouses allows implementing and testing controllers for residential Demand/Response, including interfaces for smart appliances.

Giuseppe Tommaso Costanzo To be completed: 2015 Project co funded by the Danish Strategic Platform for Innovation and Research

Coordinated control of wind power plants and energy storage systems

Wind power is one of the most popular renewable energy solutions for the future. Because of its stochastic characteristics, wind power is constantly fl uctuating and this can result in power system instability if large amounts of wind power are directly integrated into the grid. Instead of solely relying on storage mediums, an alternative coordinated control approach is proposed, which can either be adopted as a standalone solution or complementing energy storage to form a more robust and cost-eff ective solution.

The proposed approach recognizes the growing expansion of renewable energy with a number of large-scale WPPs expected to be dispersed throughout the grid. Coordinated control between them to make appropriate usages of their individual merits, attributed by their technical characteristic features as well as geographical and climatic conditions, is therefore a possibility that currently has not been addressed thoroughly, and is now recommended for investigation.

The object of this control framework is to coordinate the operation of WPPs and energy storage systems to reduce the fl uctuation of wind power production and utilize the reactive power capabilities of wind power plants to improve the stability of the whole system. Haoran Zhao To be completed: 2014

DTU funding

Overvoltages and protection in off shore wind power grids

The failure rate of components in off shore wind power plants is unpredictable. Consequently, there is a need to produce guidelines regarding the modeling of electrical equipment and methods to assess the transient and temporary over voltages correctly, known to appear in the collection grid of large off shore wind farms.

A core subject will be the analysis of available measurements in off shore wind farms with the aim to create digital models of the main electrical components in the collection grid. Once the simulation results and measurements (model validation) are in agreement, transient and temporary overvoltage studies will be carried out to estimate the potential risks correctly.

Based on these models and studies, protection schemes and systems can be evaluated to create the best technical solution to ensure a more reliable wind power plant.

Completed: 2012

Dong Energy DK, Industrial PhD Iván Arana Aristi

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Integrating control strategies for intelligent power distribution systems

In the near future, there will be a large amount of fl uctuating renewable electricity production units such as microCHP, wind power, photovoltaic’s as well as a large scale of new consumptions, e.g. electric vehicles and heat pumps. It is expected the maximize value of fl uctuating renewable electricity production can be utilized by activation of fl exible consumer demand, e.g. electric vehicles, heat pumps; however, the emerging of new electric devices will introduce new extra load to the distribution system, which may cause unexpected overloading problem.

The goal of this project is to develop and integrate control policies for the maximal utilization of the renewable energy resource while reducing the congestion problem caused by the large penetration of electric vehicles etc. The control policies range from decentralized control by price signals to centralized control in the form of virtual power plant. These control polices will be simulated on a power system model. It is expected that benefi ts can lie on the fact that the intelligent control can reduce the operation cost of integrating such large amounts of renewable electricity production and consumption and the need for reinforcements in the distributions.

To be completed: 2014 Junjie Hu Project co-funded by the Edison Consortium, the Ministry of Research, Innovation and Higher Education and the China Scholarship Council

Wind turbine generators with reduced need for rare earth metals

Securing a stable supply of rare earth permanent magnets (RE PM) has become a major issue, due to the increased worldwide demand and the concentration of resources in China. Modern wind turbines are heavily dependent on RE PM, which make them vulnerable to fl uctuations in the RE market. To minimise the dependence on RE materials, competitive alternatives to RE PM wind turbine generators will be developed.

The performance of the alternative generators, such as non-traditional induction, synchronous and reluctance generators will be compared based on overall drive-train cost, effi ciency and reliability. The comparison will be carried out by optimal design methods, usage of fi nite element analysis and aided by down-scaled prototypes that will be constructed as part of the assessment.

The project off ers an interesting challenge in machine design, and the results will benefi t designers and users of electrical machines in both industry and academia.

To be completed: 2014

Matthew Henriksen Project co-funded by: DONG Energy

Superconducting wind turbine generators

The energy need of the world’s growing population is forcing restrictive measures as to the effi ciency of today’s energy production and ‘green’ energy. More effi cient electrical machines in the wind industry will lead to better

exploitation of green energy and a decrease in CO2 emission. Another important attribute in the wind industry is the power density, especially in the off shore sector, where the size of the turbine is expected to approach 10 MW.

The objective is to investigate the benefi ts of superconductors (SC) in electrical machines focusing on wind generators. Carrying DC current at cryogenic temperatures without energy loss, SC coils can generate magnetic fi elds up to 10 T. Consequently, SC machines have higher power density and are smaller and lighter. Increase in effi ciency, better stability, smoother operation and a better dynamic performance are other expected attributes.

Light weight and more effi cient, direct driven wind generators in the power range of 10 MW are necessary to allow the advancement of the off shore wind industry. SC machines can deliver that.

Completed: 2012

Nenad Mijatović DTU Funding

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Electric vehicle integration using the virtual power plant concept: communication and optimization

The purpose of a virtual power plant (VPP) is to actively integrate distributed energy resources (DERs), such as electric vehicles (EVs), in the power system and market. This is done by introducing an aggregated system where multiple DERs are partly or fully controlled by a single coordinating entity.

The PhD project covers both the ICT standards and protocols that will facilitate communication between EVs, VPP ag- gregators, and end-users, as well as the control and logic necessary to optimize the operation of such an aggregator. Relevant topics such as security, reliability, interoperability, and performance will be evaluated as well as mathematical prediction and decision methods.

The ultimate goal of the PhD study is to investigate how the above technologies and methods can minimize the adverse eff ects of introducing EVs into the power system and to maximize the value to the EV owner, the power system, and society as a whole. The project is tightly coupled to the EDISON and VPP projects in which IBM and Centre for Electric Technology participate. Peter Bach Andersen To be completed: 2013

Project co-funded by EC Power A/S

Integrated ICT and electric power distribution system design

Information and Communication Technologies (ICT) enable new applications in the electric power system such as the coordination of distributed energy resources, and remote sensing. Despite falling costs for ICT resources, they still represent a signifi cant investment, and an economically effi cient power system must target their use to the services with the highest value.

The purpose of the project is to develop and evaluate a methodology for optimizing the planning of electric power distribution systems and telecommunication systems as an integrated entity. The project will identify the tradeoff s that exist when allocating resources between the two sub-systems. Software tools to assist the planning and integrated design will be implemented to demonstrate the utility of the proposed design paradigm.

Power systems designers will then have tools which allow them to expand their system boundaries to include ICT resources.

To be completed: 2013

Philip Douglass Project co-funded by EcoGridEU

Dynamic load optimization in a cable based transmission grid

The future cable based transmission grid in Denmark generates a number of challenges, the one of which is the optimization of the loadability of the underground cables, taken into consideration the actual conditions. The safety margins included in all cable installations cover all, also unknown, internal and external conditions. However favourable conditions allow for harder loading of cables than under the often assumed worst case situation. Hence, the standard way of dimensioning can be considered as being conservative.

In the project, all criteria used in dimensioning transmission cables have to be investigated. Thermoelectric models have to be developed and optimised for enhancement of real-time loadability estimation of cable systems. Together with actual information from the grid operator, the models form the base for real-time loadability prognoses. The infl uence of optimized operation characteristics on the lifetime of cable and accessories has to be investigated, including reliability analyses for point-to-point cable systems.

The outcome of the project enables transmission system operators to increase utilisation of transmission cables, estimate fault probabilities and remaining lifetimes in the “Future Denmark” transmission grid. Rasmus Schmidt Olsen To be completed: 2013

Energinet.dk, Industrial PhD

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Real-time analysis of an active distribution network – coordinated frequency control for islanding operation

The increasing penetration of distributed generation and distributed energy resources, and the consequential requirement to accommodate and integrate them within distribution networks brings both challenges and opportunities to the system operator. The presence of DERs within the networks makes it possible to operate the networks independently, which is called islanding operation. However, it is a challenge to ensure reliable operation of the islanded system due to a number of reasons, e.g. low inertia, intermittency of the DERs, etc.

The goal of this PhD project is to develop eff ective frequency control strategies for the islanding operation of active distribution networks. During the islanding transition, the frequency is regulated by the fast-acting primary control of the BESS, while other dispatchable DGs act as a supplementary to maintain the frequency constant.

A fuzzy logic/agent-based secondary frequency control strategy for the islanding operation of ADN is proposed. Simulation indicates that the frequency performance is highly improved.

Seung Tae Cha Completed: 2012 Project co-funded by Energinet.dk

Modern electricity distribution grids with high share of solar energy

Photovoltaic (PV) systems are among the fastest developing generation technologies in the current world. It is anticipated that the majority of the coming installations are interfaced with the distribution electric grids. Despite the benefi ts of PVs, there are challenges associated which give rise to the security and quality issues of power delivered at the distribution systems.

The project will investigate the main operational barriers of increasing the PV penetration at the distribution grids, by applying the state-of-the-art inverter technology to support the system security and control. The eff ects of new SmartGrid functionalities and ancillary services incorporated into the PV system will also be examined.

The project will provide technical solutions to facilitate the high PV integration into the network with less reinforcement of the current power grid.

To be completed: 2015

Project co-funded by Energinet.dk Seyedmostafa Hashemi Toghroljerdi

Reducing dependency of critical materials in rotating electrical machines by designing for recyclability and reusability

Rare-earth metals are increasingly being used in rotating electrical machines due to their superior magnetic properties that can have an increasing eff ect on the torque-density of machines. Rare-earth metals are associated with uncertainty in supply and price which have spurred research in reducing the volume of material needed in a machine. New machine designs could help reducing the amount of rare-earth materials in electrical machines

In this PhD project the possibilities of designing rotating electrical machines, in which the volume of rare-earth metals is reduced, and where the design facilitates easy dismantling and reuse or recycling of these, will be researched.

It will consist of a literature review of the current state-of-the-art, describing existing methods of reducing critical materials in electrical machines, and outlining the current construction methods. Design investigation of one or more machines e.g. a wind turbine generator and/or a pump motor, with focus on developing new methods that ease recycling of the critical materials will follow. Modeling, simulation, and evaluation of new designs is then investigated. Prototypes will be developed based on earlier fi ndings, and experimental performance testing of these as well as Stig Högberg practical assessment of their recyclability is the concluding part of the project.

To be completed: 2015

Project co-funded by the Danish Agency for Science, Technology and Innovation

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Fast dynamic evaluation of N-1 criteria

The further increasing fraction of electric energy generated from renewable energy technologies, will make today’s tools for stability assessment insuffi cient. This is due to the fact that today’s tools use non-controllable and on forecast accuracy depending energy sources such as wind and solar radiation depending on extensive off -line computations. Phasor measurement units (PMU), which provide synchronized measurements, enable wide-area monitoring in power systems.

The PhD project is part of the SOSPO project and its objective is to develop a method, which utilizes those synchronized measurements to dynamically evaluate the stability of the power system in case of facing a severe perturbation, e.g. a loss of a generation unit. The method analyses the ability of the power system to survive the transient system response as well as its capability to reach a new stable steady-state operating point.

The project outcome will improve the system state awareness of the system operator and may provide supporting information to identify effi cient control actions to improve the stability condition.

Tilman Weckesser To be completed: 2014 Project co-funded by the Danish Council for Strategic Research

Impact of wind power on power system small signal stability and wind turbine small signal stability models

In recent years power systems around the world have experienced and are experiencing an immense growth of installed capacity of wind power. And as such, wind power is playing an ever larger role in the balancing and the stability of electrical power systems. From a system perspective this increases the requirements to the wind turbines, as they are expected to support stable operation of the power system.

Here only the implication of wind power on dynamic stability of power systems is investigated. The project seeks to establish how the wind farms should be effi ciently modeled for the analysis, which eff ects the wind farms have on the dynamic stability, and whether the wind farms can contribute positively to the stability.

Insight into the interaction of wind power and dynamic stability will enable further expansion with wind power in power systems suff ering from dynamic stability issues.

Completed in 2012

Thyge Knüppel Siemens Wind Power A/S, Industrial PhD

Modeling of demand response and its impact on a distribution grid using fi eld trail data of household appliance control at multiple consumers

One of the challenges for the reliable and economical operation of a power system with a high penetration of renewable energy is the availability of energy resources which can participate in balancing supply and demand on a short-term basis. For example, by infl uencing the operation of electrical loads at customer premises the demand can be adjusted to balance with supply. The uncertainty in this situation is the degree of interest and cooperation from customers.

The aim of this PhD study is to analyze the impact of demand response activations on the distribution grid. A model of demand response activation’s impact on the grid will be developed, allowing for up-scaling and describing aggregated behavior by involving a large fi eld experiment with a few hundred to thousand consumers.

The fi eld experiment will be conducted on the distribution grid of a project partner and with the support from a hardware control and power measurement device manufacturer. The analysis and modeling will be done by using the data recorded from the energy meters and the power measured from the device controlling the refrigerators. Venkatachalam Lakshmanan To be completed: 2015

Project co-funded by the Danish Agency for Science, Technology and Innovation

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Transient conditions and protection in HVDC off shore grids

Transients in HVDC grids diff er mainly from transients in HVAC grids in relation to the diff erent components involved. In HVAC grids, transformer – breaker – cable confi gurations usually are in focus under diff erent operational situations. In HVDC transmission systems and grids the situation is dominated by converter – fi lter – breaker – cable confi gurations. In order to give a thorough picture of all relevant transients, the infl uence of switching events on the AC-side coupled to the converters is included as well. The fi ndings apply mainly to off shore point-to-point and multi terminal transmission systems but are relevant to other possible future confi gurations as well, like HVDC collection grids. Initially, general relations concerning switching operations and fault conditions in a HVDC system will be investigated, in particular with respect to component exposure, interaction with the system and protection. These fi ndings will mainly apply to HVDC connections between wind farm collection grids and transmission grids. The considerations of such point to point transmission systems will be followed by studies of other possible future confi gurations with more than two terminals. In order to assess current and voltage related transient conditions, numerical methods will be used for time domain simulations. Broad band component models, developed at DTU in Walid Ziad El-Khatib earlier projects have to be included in order to achieve results with satisfying temporal resolutions.

To be completed: 2015

Project co-funded by Energinet.dk

Distribution grid with embedded generation – impact, control, and design

The deployment of renewables, in particular solar with intermittent features, is dramatically increased recently. Meanwhile, with conversion of other resources into electricity, new load patterns, such as electric vehicles and heat pumps, are introduced into the electricity grid. Thus, it is essential to study the impacts of these DERs and furthermore to design the control strategies to coordinate and to make the optimal use of them from a system level.

This project is focused on the behavior of diff erent kinds of DER facilities from the grid side, and moreover on proposing control strategies and methods to accommodate DERs by utilizing the fl exibility of DER themselves and energy storage to a maximal extent. The project is part of iPower Project WP3, on distribution grid operation to identify the network constraints when facing a large amount of DERs in the system.

With the models and methods proposed in the project, it is possible to mitigate the negative impacts of DERs, and instead the integration of DERs could contribute to the grid operation.

To be completed: 2015

Xue Han Project co-funded by the Danish Strategic Platform for Innovation and Research

Optimal operation of distribution networks with electrifi cation of transport and heating sectors in nordic region

The Nordic region has suffi cient renewable energy source (RES) potential to develop a fully carbon neutral electricity system. Under further utilization of RES, the electrifi cation of the transport sector and partly of the heating sector by large scale deployment of electric vehicles (EVs) and heat pumps (HP) can off er possibilities for balancing and storage of electricity to cope with variability in load and RES production.

The project is to investigate the impact and potential of electrifi cation of transport and part of the heating sector in Nordic region. The constraints of transport sector, heating sector and the power grid will be analyzed. The feasibility of combining the schedule management and ancillary service provision will be investigated by using the prognosis of ancillary service prices.

The project will provide knowledge and understanding to decision makers and actors in the power industry about the possible carbon neutral future for an integrated Nordic power system in 2050.

Zhaoxi Liu To be completed: 2015 Project co-funded by Nordic Energy Research

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 ELECTROMAGNETIC SYSTEMS T Finally, theproject • • Th • Th In 2012we successfully completed 3major ESAprojects launched in2009, and theESAsatellite BIOMASS currentl (ESA); among many projects are theDanish Ørsted satellite launched in1999, theESAsatellite SMOS is heavily involved through inspacetechnology extensive cooperation with theEuropean Space Agency performance requirements –and thus isamajor driver for research inelectromagnetic systems. EMS application challenging Space isavery area for te theresearch thewidespan of of activitiesoverview carried out by PhD students. research and innovation. All our PhD projects inthefollowing are described pages provide which agood at more basicresearch. activities Both are essential and we intend to maintain aproper balance between eff very a constitute A/S, Ticra and Weibel Scientifi cooperation with theDanish companies GNResound A/S, MTIRadiocomp, Terma A/S, Th As inprevious years EMSwasengaged PhD number projects inahigh were of in2012; which in 6of public organizations or theprivate industry. Most our research of isconducted inclose cooperation with Danish or foreign from partners academia, region –300MHz to 300GHz –with applications incommunication, imaging, measurement, and sensing. research. Ourmajor research activities dealwith antennas, components and circuits within themicrowave courses at BEng, BSc, MSc, and PhD courses level aswell and asspecial thesisprojects closely linked to our with computational techniques testing inhigh-quality and laboratories. experimental We off Head of group: Professor Olav Breinbjerg planned for thismission. of near-fiof cooperation with Ticra, Th Facility. refltraditional PhDstudent,industrial resulted innovel asfor analysis techniques that accuracy allow high asimilar with ESA. Spherical Near-Field Antenna Test Facility islocated which at DTU and operated by EMSincooperation near-fi high-accuracy e e project e project ranging from –combining to basicelectrostatics technology advanced terahertz theoretical analysis he Electromagnetic Systems (EMS)group conducts research and teaching inareas electromagnetics of eld measurements that enable theverifi Advanced Refl HONFP –Higher-Order Near-Field Probes ector antennas; wasverifi thisaccuracy ective frameworkective for researchbased innovation PhD projects theDTU while based aim BIOMASS P-Band Antenna Performance Verifi eld measurements satellite of antennas in ales Alenia Space, Italy and DMO, Th ectarray ectarray Antennas c 7wereA/S while in-house projects. Th , conducted incooperation with Ticra and involving one chnical science sinceit presents science chnical extremely stringent cation of the very largecation thevery 15mrefl of ed byed extensive measurements at theDTU-ESA resulted in a new type of probe antennas resulted of type inanew for y inphase ExplorerA within theEarth program. eNetherlands, resulted type inanew support of the activities of the DTU-ESA theDTU-ESA theactivities support of of cation Methodology e industry supported PhD projects eindustry ector antenna system , conducted in in , conducted rane &Th er regular rane rane In parallel, we continue several other ESA projects; e.g. the operation of the DTU-ESA Facility and the strong engagement in the BIOMASS mission through cooperation with Th ales Alenia Space, Italy SELEX, Italy and TNO, the Netherlands. Furthermore, several other EMS projects supported by the EU, the Danish National Advanced Technology Foundation and others, concern antenna and microwave components/circuits for space applications.

In 2012, EMS’s agelong cooperation with Professor Richard W. Ziolkowski, University of Arizona (UoA), USA within the areas of antenna miniaturization and metamaterials was not only continued, but also celebrated when Professor Ziolkowski received DTU’s highest academic degree, the Honorary Doctor degree Doctor Technices Honoris Causa at the annual Commemoration of DTU in April 2012. Professor Ziolkowski has been a close collaborator of DTU for several years and the degree was awarded in recognition of “outstanding and seminal contributions to metamaterial-inspired antennas”. Since 2005 our collaboration has involved several mutual visits between UoA and DTU and resulted in more than 20 joint publications.

Overall, 2012 was another productive year for EMS where we initiated 2 new PhD projects, started 5 new externally funded projects, and reached a total of 43 publications in international journals and conferences.

Electromagnetic Systems Group – September 2012 Back: Oleksly Kim, Olav Breinbjerg, Jens Vidkjær, Tonny Rubæk, Martin Nielsen, Sergey Pivnenko, Kaj Bjarne Jakobsen, Jan Normann Mortensen, Rasmus Schandorph Michaelsen Midle: Jeppe Majlund Nielsen, Johan Jacob Mohr, Vitally Zhurbenko, Ick-Jae Yoon, Peter Damsgaard Jensen, Niels Christian Jerichau Clausen, Samel Arslanagic, Th omas Gunst Smith Not present: Søren Helstrup Kvist, Sævar Tor Jónasson, Carlos Cilla Hernández.

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Advanced techniques for EMI control and EMC optimization in miniaturized devices

One of the well-established trends in electronics is miniaturization: this assumes a whole new perspective when it is considered that radio, digital, and audio sub-systems must coexist on a physically- and electrically-small PCB, as it is today in the hearing aids. The overall quality of the system can be easily degraded by overlooking the interactions of these electronics subsystems.

The lack of freedom in both the electrical and mechanical design forbids traditional, space-demanding EMC techniques, whereas the advent of modern multi-physics and co-simulation tools is paving the way to the analysis of the dynamics underlying self-jamming. The project is based on a full electromagnetic modeling approach (i.e., the use of Maxwell’s Equations) to ease the understanding at system level.

Ideally, the project will provide enhanced understanding of the physics interactions within complex, miniaturized environments and develop techniques for EMC optimization.

To be completed: 2015

Andrea Ruaro GN ReSound A/S and the Danish Agency for Science, Technology and Innovation, Industrial PhD

Wireless communication for hearing aid systems

The objective is to develop key technologies enabling very small autonomous devices – like e.g. hearing aids – to be incorporated in wireless networks. A key bottleneck as regards the practical realization is the size and effi ciency of the antennas and the supply and consumption of energy of the devices. Specifi c focus will be on antennas, encapsulation and packaging, and wireless transfer of power.

The project comprises three major areas of investigation – ear-to-ear communication, propagation measurements and magneto-dielectric antennas. Wireless coupling between hearing aids will be characterized based on theoretical simulation and practical measurements during the fi rst half of the project. The second part will be concerned with the minimization of antennas using materials that have a high permittivity and permeability.

Most studies of wireless communication concern far-fi eld communication, while this project is focused on communication in the reactive region of antennas.

Completed: 2012

Baqer Nour Project co-funded by the Danish Advanced Technology Foundation and the Danish Technological Institute

Microwave instrument for vital signs detection and monitoring The fi rst experimental results of using microwave instruments, e.g. radar and radiometers etc. for detection and monitoring of human vital signs like heartbeat and respiratory activity was published in the 1970s. Since then, numerous publications have treated this subject in order to establish the fundamental theory and to test the viability of such a non-contact vital signs instrument.

The human respiratory and heartbeat movements are relatively slow, thus they occupy frequencies close to any radar transmitted signal. Therefore they are often cluttered by the inherent phase noise of the transceiver. The purpose of the PhD project is to design, implement and verify compact, low-power radar components for vital signs radar (VSR) use in a modern, commercially available SiGe:C technology. The ideal outcome is a complete radar chip for VSR.

The applications are many. One example is to use the instrument for monitoring patients at hospitals for increasing patient mobility and ease the use of such instruments for staff .

Completed: 2012 Brian Sveistrup Jensen DTU funding

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Development of high power amplifi ers for radar applications

Advanced radar systems have received considerable attention due to the increased demand in remote sensing and imaging applications both for terrestrial and space systems. One of the key elements in this system is the high power amplifi er, which has experienced a renewed interest due to the enormous progress in solid-state technology and devices. An emerging technology particularly promising for high power amplifi er realization is GaN device technology.

The scope of the PhD project lies in the development of design methodologies, nonlinear modeling, manufacturing, packaging and effi cient testing of solid state high power amplifi er modules. A further goal is to develop a high power amplifi er for X-band frequencies with capabilities to replace the vacuum tubes currently used in commercial radar systems.

Advances in high power amplifi er technology will help reducing the system size and cost, and enhancing transmission rates and target detection

To be completed: 2013

Carlos Cilla Hernández Project co-funded by TERMA A/S

Design of integrated circuits approaching terahertz frequencies

For a few years now, there have been very intense development eff orts worldwide on imaging for security applications. The market for mm/sub-mm wave components and modules will thus probably grow signifi cantly. Furthermore, it is expected that mm/sub-mm wave imaging will increasingly be developed for space and military applications.

The objective is to design and characterize MMIC circuits for the frequencies starting at E-band and up to 600 GHz with improved performance in terms of output power levels and effi ciency. The objective of E-band project is to develop millimetre-wave power amplifi ers meeting the requirements for E-band applications around 73.5GHz and exploring the capabilities of InP HBT technology for power amplifi ers at these and higher frequencies for communication and sensing applications. In order to fulfi ll the specifi ed output power level, scalable HBT model, effi cient power cell, thermal coupling and even/odd mode circuit stability issues have been solved respectively. The fi nal MMICs are being implemented at commercial foundry now.

The project results will be MMIC components LNA, mixer, and power amplifi er for receiver and transmitter applications in millimeter-wave bands and at least one MMIC operating beyond 300 GHz. Lei Yan Completed: 2012

DTU funding

Planar antenna technology for broadband satellite-based communication systems at K/Ka-band and beyond

The demand for high bandwidth to satisfy the requirements for increasing data transfer rates from a wide range of end-users is accelerating, and the global satellite industry is responding to this demand by expanding the services to higher and higher frequencies. Traditional antenna technologies such as phased arrays struggle with increasing losses at higher frequencies, and refl ectors with an inconvenient form factor.

The aim of this project is to investigate antenna technologies which make it possible to implement low-profi le compact user terminals accessing satellite communication services at K/Ka-band and above.

Accurate modeling and optimization of such antennas constitute one of the main objectives, since commercially available software is often inadequate due to the large computational cost associated with modeling highly directive antennas.

A compact and highly directive antenna technology along with a well-documented design- and modeling procedure Mikkel Dahl Hougs will prove valuable in the future of satellite communication. To be completed: 2015

DTU funding

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Accurate modelling of advanced refl ectarrays

Refl ectarrays combine the best features of refl ector antennas and array antennas, and is considered as a promising candidate for realizing low-cost high-gain antennas for satellite communications. The design and realization of advanced refl ectarrays rely heavily on numerical analysis, and accurate analysis of refl ectarrays is presently a challenging problem. In addition, refl ectarrays tend to have smaller frequency bandwidth compared to conventional refl ector antennas.

This project is aimed at proposing solutions to the lack of accuracy in present refl ectarray modeling and to develop new algorithms for synthesizing and analyzing refl ectarrays. The project will set a new standard for the modelling accuracy of refl ectarrays and consequently make it possible to design such antennas with much better agreement between measurements and simulations.

It is expected that improved modelling tools will enhance the performance and usability of refl ectarrays, and greatly contribute to solving the bandwidth issue associated with refl ectarrays.

Min Zhou Completed: 2012 Project co-funded by Ticra and the Ministry of Science, Innovation and Higher Education

Homogenization and realization of periodically structured materials

Periodic structured materials can be tailored to realize metamaterials for microwave as well as optical frequency applications. However, a central and signifi cant challenge in the structured materials research, that is still a matter of controversy, is the homogenization of these, i.e., the determination of their eff ective material parameters.

The purpose of this project is to further develop electromagnetic homogenization techniques for structured materials and apply them to improve the design, realization, and experimental characterization of a broad range of metamaterials.

It is expected that this study will provide additional insight into the general behavior of periodic structures and the homogenization conditions for realistic structured dielectrics.

To be completed: 2014

DTU funding

Niels Christian Jerichau Clausen

Reconfi gureable microwave fi lters for communication systems

The increasing number of access technologies in cellular mobile communications creates a proportional demand for dedicated types of transceivers. Signifi cant savings could be made if a single base station transceiver were to support multiple access protocols at diff erent bands, which is expected to be the trend in the next generation radio systems. For this to happen, low-loss, widely tunable microwave fi lters are needed, which are not yet available.

This project is dedicated to research in tuning methods for fi lters that will only minimally degrade the performance. In addition to aiming at wide tuning ranges as well as bandwidth control, the resulting fi lters are expected to be very low-loss and have high power handling capability. For this purpose, ferroelectric materials, ferromagnetic materials or metamaterials will be integrated into inherently high-Q resonator structures.

As a result, it will be possible to use a single transceiver hardware platform to meet various specifi cations, meaning a major reduction in production and engineering costs.

To be completed: 2014 Öncel Acar Project co-funded by MTI Radiocomp

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Assessment and development of microwave imaging for breast cancer detection

Microwave imaging is proposed as an alternative to X-ray mammography. The diff erent approaches that currently are being pursued can be divided into two groups: Ultrawideband radar-based methods in which the images are constructed by determining the point-of-origin of refl ected pulses, and tomographic or inverse-scattering techniques in which the images are created by solving an inverse scattering problem based on Maxwell’s equations.

A prototype system is currently being developed as part of the project belongs to the latter group. The system consists of 32 antennas, each equipped with their own transceiver module used for collecting the measurement data. Inverse scattering algorithms are applied to create 3-D images from the measured data. The project focuses on development of the prototype system, improved inverse algorithms and experimental validation.

Potential advantages of microwave imaging are the use of non-ionizing radiation, better sensitivity to cancer tissue in young women, and a lower cost of the system.

To be completed: 2013

Peter Damsgaard Jensen Project co-funded by the Villum Kann Rasmussen Foundation

Custom made front-end MMIC for X-band radar, with focus on low phase- and 1/f-noise

In high precision Doppler radars, the limiting factor for precision is the noise contribution. As these systems get bigger and more complex requiring several receivers in a phased array, miniaturization and mass production capability will be required. Microwave monolithic integrated circuit (MMIC) technology has these properties.

The goal of the project is to construct a custom receiver front-end MMIC, which should consist of LNA, splitters and dual I/Q mixers with diff erent LO frequencies. All of these elements should be designed to have an extremely low noise contribution. The main research focus will be on the noise contribution from the diff erent elements of the frontend, especially the 1/f noise from the mixer.

There is a limited knowledge about 1/f noise, especially in nonlinear components, therefore intensive research into noise contributing elements is a key element of this project.

To be completed: 2014

Rasmus Schandorph Michaelsen Project co-funded by Weibel Scientifi c

Microwave activation of drug release

There are several disadvantages concerning conventional medical drug delivery such as pills and capsules taken orally. They often have low drug penetration through the gastrointestinal wall, degradation of the active pharmaceutical components in the stomach and lack of control of the actual time and/or place of the release. Therefore another drug delivery method is proposed, using microwaves to control the release of the drug.

The objective is to design an array of microwave transmitters, whose phases and amplitudes are controlled in a way to create a constructive interference of the transmitted waves and by that, focus the electromagnetic fi eld to a pre- determined area inside the human body. The project includes EM simulation and hardware development as well as a proof-of-principle testing of the system on simplifi ed phantoms.

By externally controlling the time and location of the drug release with microwaves, gives increased fl exibility and effi ciency in medical drug intake.

To be completed: 2013 Sævar Þór Jónasson Project co-funded by the Villum Kann Rasmussen Foundation

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Antennas and propagation for body-centric wireless communication

Body-Centric Wireless Communication is the enabling element of Wireless Body Area Networks, consisting of two or more body-worn devices. These devices could e.g. be medical sensors for monitoring the health of a patient, or wireless headsets. The challenge is twofold when designing antennas for such devices; The close proximity of human tissue drastically aff ects antenna performance, and the antenna is often confi ned to a small volume.

The project focuses on the implementation of wireless capabilities in hearing aids. These tiny, yet highly advanced devices constitute a challenging platform for wireless communications. The hearing aids should be able to communicate among themselves, and with other devices, either body-worn or off -body. The applicable radio channels will be characterized, and appropriate antennas designed.

Wireless-enabled hearing aids off er a range of new features compared to traditional hearing aids.

To be completed: 2013

Project co-funded by GN Resound A/S Søren Helstrup Kvist

Hybrid maritime satellite communication antenna

As the world moves online, the demand of broadband communication is rising in the maritime industry. However, in the harsh working environment, the stability of the communication link is a key issue but also a problem in high- frequency broadband communication, where i.e. clouds and rain can attenuate or even block all communication.

This project targets the design of new antennas for reliable broadband communication in the maritime environment, with emphasis on hybrid antennas for multiband operation. New technologies are needed to meet the industry specifi cations to both electromagnetic performance as well as mechanical demands, which necessitate development of new antenna elements and operation.

The new type of maritime satellite antenna will enable broadband communication in the maritime environment with the highest possible reliability, and knowledge in the fi eld of multiband hybrid antenna elements.

To be completed: 2013

Project co-funded by Thrane & Thrane and the Ministry of Science, Innovation and Higher Education Thomas Gunst Smith

Metamaterial homogenization and antenna miniaturization

Some of the major challenges of antenna miniaturization are to maintain an acceptable bandwidth and effi ciency when reducing the antenna size. Recent (2008-2009) research at EMS have shown that highly miniaturized antennas are archived when using innovative resonant structures of the type suggested for unit cells of certain metamaterials, and furthermore employing magnetic materials, makes it possible to approach the fundamental limit of available bandwidth for a given antenna size.

The aim of this project is to expand upon and clarify the understanding regarding metamaterial homogenization and to apply it for development, design, and realization of certain metamaterials and highly miniaturized antennas that are practical in terms of bandwidth and effi ciency. The latter is archived through an extensive study of several generic confi gurations of small antennas, which all seek to diminish the stored energy.

It is expected that a more coherent description of metamaterial homogenization will be obtained, as well as an account of pro and cons for the various types of small antennas including designs of practical value.

Troels Vejle Hansen To be completed: 2013

Project co-funded by the Ministry of Science, Innovation and Higher Education

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 47

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 ELECTRONICS W An international environment • • Extensive skillsincombining and simulation theory • • A staff have: We Student thesisprojects (BEng, and MSc) BSc • Research projects (PhD etc.) • We collaborate with both domestic and international industrial partners on: 4start-up companies • • 18 inventions • Numerous scientifi We provide unique and innovative solutions to our collaborating and partners to Danish society: Our PhD students have ranked comparable been to PhD students intop USuniversities. transformer Piezoelectric switch-mode based power supplies –obtained by employing aself-oscillating • Switch-mode (class D)audio power amplifi • Head of group: Professor MichaelA.E.Andersen • High effi We continue world to be research leaders within: density. switch-mode powerfrequency supplies, where there are exiting new possibilities for increasing thepower with industrial partners on diff transformer power based supplies. areas focus In these we each have of PhD students several collaborating power supplies and technologies, class-D switch-mode audio power amplifi Currently our research within theareas: isfocused power converters for renewable energy, switch-mode researchperform conditioning within signal electronics aswell asanalogue and IC-design. mixed-mode State-of-the-art lab equipment and an attractive student environment high effi high record cellpower fuel converter holder of effi optimization thepower and losses thephysical of losses. properties these behind Th measurements, and validations world’s fi temperature and aging. We have invented also an active phase angle control enabling usto show the control invented by usto maintain resonance thepiezoelectric independent tracking of mode of loop control systems sampling state-of-the-art these phase-shift and of modeling effi and combined with theconverters theimpedance levels of inallparts component-, and system levels ranging from mega-Watt to milli-Watt power converters. We also e conduct fundamental research aswell asapplied research inpower electronics on physics, with mixed university/industry background and experience knowledge aswell level of asahigh ciency ciency specifi cient DC/AC power conversion and without sacrifi ciency fuel cellpower fuel convertersciency –obtained by both system level and component level rst bi-directional power fl c papers ininternational journals and conferences cation have reached by been research into mixed continuous and discrete time erent applications. areaA new that we have to doresearch started inisradio ow transformer piezoelectric power based converter. ers during –developed more than research 20years of into ciency isaholistic allthelossmechanisms understandingciency of s with practical implementation and experiments, cing theaudio quality. to none Second audio and hysteresis self-oscillating multi based ers, aswell ason piezoelectric e key to ekey world being Facilitating the increasing use of electronics in our society – all requiring power conversion being “green” and energy effi cient – we conduct research in methods to increase the power density and energy effi ciency of power electronics by using:

• Piezoelectric transformers – expanding this from DC/DC to both DC/AC and AC/DC power converters for numerous applications as well as to piezoelectric actuator drives • Radio frequency SMPSs – novel research into the combination of radio frequency techniques and power electronic resonant converters using the newest GaN and SiC semiconductors. Th e potential of drastically reducing the size of power converters will be pursued as our initial research has shown a 60% size reduction already • Smart solutions to integration, ﬂ exibility, and cooling of power electronic converters for various renewable energy applications.

We will also exploit the possibilities for combining the competences within integrated circuit design and power electronics.

An initiative we call “Electronics for Sound Systems” will be pursued based on the strong Danish industry with several companies dedicated to various types of sound systems. DTU has several research activities within the technical disciplines required for sound systems but they are not necessarily conducted with an emphasis on the application to sound systems. Th e platform “Electronics for Sound Systems” places the technical disciplines in a context which is highly relevant in a Danish perspective. Th us both the technical disciplines and the application ﬁ eld of sound systems will thrive and this platform will become a framework for research projects related to sound systems.

One of our largest research projects seeks to increase the effi ciency and the power density of power converters used for LED lighting. Th is project is funded by the Danish Ministry of Science, Innovation and Higher Education. In another very large research project, funded by the Danish Advanced Technology Foundation, we do research into light weight energy effi cient power electronic drivers for Dielectric Electro Active Polymer (DEAP) actuators. Th ese require high voltage drive as well as energy recovery from the capacitive nature of the DEAP actuators. In the research project “Intelligent Effi cient Power Electronics” also funded by the Danish Advanced Technology Foundation, we do a more strategic and long term research into increasing the effi ciency and power density of power electronics in collaboration with major Danish companies.

Comparison of two power supplies for the same LED lamp. Top: Commercial product. Bottom: DTU Elektro VHF-SMPS prototype with same eﬃ ciency and 80% volume reduction.

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 PV inverter and control

A crucial aspect in the integration of photovoltaic (PV) into the grid is the power converter and its requirements, i.e. mainly effi ciency, power density and price. Wide band gap power switches made of silicon carbide (SiC) and gallium nitride (GaN) combine the positive characteristics of IGBTs and MOSFETs so that the new kind of power switches have high breakdown voltages with low conduction losses as well as fast switching transitions.

This research project deals with the utilization of wide band gap power switches in PV inverters. Diff erent wide band gap power switches will be investigated and thereby, not only advantages such as lower switching losses, better cooling and reduction of fi lter size but also challenges like optimal PCB layout, control, harmonics attenuation and both lifetime and reliability of the converters analyzed.

With wide band gap devices successfully implemented, the overall behavior of PV inverters will be improved to match the requirements and new standards set.

To be completed: 2015 Alexander Anthon Project co-funded by Danfoss A/S, Grundfos A/S, KK-elektronics A/S, Vestas A/S and the Danish Advanced Technology Foundation

Class-D amplifi ers for DEAP loudspeakers

Switch-mode audio power amplifi ers are commonly used in sound reproduction driving electromagnetic-mechanical transducers. While these audio systems are dominating the market of sound reproduction, they still suff er from the poor effi ciency imposed by the electromagnetic-mechanical transducer. It is proposed to replace the traditional electromagnetic-mechanical transducer by an electrostatic transducer constructed from Dielectric Electro Active Polymers (DEAP).

The objective of the project is to research into Class-D switch-mode audio power amplifi ers for driving a DEAP (dielectric active polymer) based loudspeaker. The loudspeaker could use the DEAP directly as a fl at membrane or use the DEAP as the “actuator” replacing the traditional permanent magnet system.

The unique properties of the new DEAP materials make it technically viable, that loudspeakers with signifi cant higher power density and effi ciency compared with the current state-of-the-art can be developed. The key research topics of the project is power stage topologies and control loop design.

Dennis Nielsen To be completed: 2014 Project co-funded by B&O A/S, Danfoss Polypower A/S and the Danish Advanced Technology Foundation

Flexible power module for fuel cell hybrid power system in a forklift

Fuel Cell Hybrid Vehicles (FCHV) are becoming a popular means of increasing the energy effi ciency and reducing emissions. In fuel cell applications, batteries are employed to reduce the size of the fuel cell, to recover braking energy during regeneration, and to keep the fuel cell in its high effi ciency region. The variable voltage of the fuel cell has to be matched to the battery voltage via a DC/DC converter for charging.

The primary objective of this research project is to select and improve a high effi cient topology from the literature for a DC/DC medium power converter for a fuel cell fork-lift application. Converter design should be aimed for easy manufacturing and complete functionality including closed loop control leading to a more effi cient conversion of fuel cell power as well as reduced size and less cooling needs.

The contributions of this project are: Single core integration of transformers and inductor for the primary-parallel secondary-series isolated boost converter (PPIBC); investigation of diff erent current balancing techniques for the PPIBC; modeling and control of both unidirectional and bidirectional PPIBC

Gökhan Sen Completed: 2012 Project co-funded by H2Logic A/S and the Danish Advanced Technology Foundation

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Switch-mode power amplifi ers for current controlled loudspeakers

Is it possible to improve the sound quality of a loudspeaker system by adding some intelligent control or feedback from the loudspeaker to the amplifi er? This is one of the questions which are investigated in this project aiming to improve the interface between the amplifi er and the loudspeaker.

In order to gain more control over the force applied to the mechanical part of the loudspeaker the output current of the amplifi er is controlled instead of the output voltage. Another possibility with current control is to improve the loudspeaker effi ciency at lower frequencies due to a decrease in electrical damping.

The outcome is supposed to be theoretical analyses and several proof of concept demonstrators. These innovative solutions could lead to better audio performance and improved effi ciency.

To be completed: 2014

Project co-funded by Loudsoft Aps, Pascal A/S and the Ministry of Science, Innovation and Higher Education

Henrik Schneider

Single phase PFC converter using wide bandgap devices

Active Power Factor Correction (PFC) circuits are often required to help reduce the grid transmission losses and to improve voltage regulation. The newly introduced Gallium-Nitride (GaN) and Silicon-Carbide (SiC) devices with high electrical fi eld strength allow for a reduction in the size of the switch die, which results in low on resistance and parasitic capacitances making possible to increase the operating switching frequency of the converter.

The main goal of this project is to analyze the improvements that can be obtained by substituting the silicon (Si) switches in a reference design with wide bandgap devices. The design will be carried out considering the improvements in power density and EMC requirements, moreover the driver complexity, the reliability, and improvements on the controllability of the converter will be considered.

The aim by introducing this new technology is to achieve a reduction in size, weight and losses of 20% compared to the reference design.

To be completed: 2015

Juan Carlos Hernández Botella Project co-funded by Danfoss A/S, Grundfos A/S, KK-elektronics A/S, Vestas A/S and the Danish Advanced Technology Foundation

High performance solar array simulator

A Solar Array Simulator (SAS) is a power electronics system that simulates the realistic behaviors of solar panels used in space or terrestrial applications so that tests of maximum power point tracking converters utilizing solar energy can be performed. The need of SASs is due to the cost and space limitation when performing tests with real solar panels. The challenges for SASs used in space applications are system nonlinearity and fast transient response.

The aim of this project is to construct a high performance SAS for space applications. The power supply unit for the SAS will have ultra low parasitic capacitance suitable for the module based approach. An ultra-fast tracking converter will be developed to achieve fast response in the SAS. The highly nonlinearity issue caused by the nature of solar panels’ I/V curves will be studied in-depth.

The expected result of this project is a superior SAS that benefi ts the space industry and contributes to the knowledge of switch mode power converters.

To be completed: 2014 Khiem Nguyen-Duy Project co-funded by Rovsing A/S and the Danish Advanced Technology Foundation

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Low power DEAP actuator drive for heating valves

Current heating valve actuators are thermal actuators, being noiseless but consuming signifi cant power, and electrical gear motors which are relatively energy effi cient, but prone to noise issues. A dielectric electro active polymer (DEAP) is a very thin elastomeric fi lm with electrode layer on both sides, which is fundamentally a capacitor. The unique properties of DEAP material make a compact in-line heating valves actuator technically viable.

The purpose of this project is to develop high voltage DC-DC converter to drive the DEAP actuator in the heating valve system in order to control the water fl ow. These high voltage converters should be small enough to be integrated into the thermostat and be effi cient enough to let the battery life exceed 10 years. In addition, the converters also need to be optimized in price to compete with traditional drives.

The new heating valve actuators with its driving converters will be an important step to penetrate the fast growing market for electronically controlled heating valve actuators.

To be completed: 2014

Lina Huang Project co-funded by Danfoss Heating A/S, Danfoss Polypower A/S and the Danish Advanced Technology Foundation

Multi-port bidirectional current controlled power supply

Solar cells and LED lightning combined with an energy storage element in a stand-alone structure provide an independent and environmental system. Due to the non-lineal behavior of solar cells and LEDs, and the bidirectional power fl ow in the energy storage element, multiple converters should be used. An intelligent control including battery management system (BMS) and maximum power tracking (MPPT) of the panel I-V curve is required.

The objective of this project is to design a multi-port bidirectional power converter that is optimized for two inputs: one of them the complex curve corresponding to the solar cell, and the other for the battery, while providing tightly regulated output current into the LED load. Diff erent multiport topologies will be analyzed and magnetic integration will be considered to increase the system power density.

By implementing a power converter which can interface with renewable sources, storage elements and loads simultaneously, compact packaging and high effi ciency can be achieved.

To be completed: 2015

Maria del Carmen Mira Albert Project co-funded by Danish Lighting Center, AKJ Inventions ApS, Modelmager Morten Lyhne, Out-sider A/S and the Danish Energy Agency

Controller IC-design for piezoelectric transformer based power supply

Dielectric Electro Active Polymer (DEAP) technology has a wide potential in applications such as surgical tools, grippers and valve actuators etc. But the limited availability of high voltage power supplies (up to 2.5kV) for the DEAP technology, confi nes the technology. The unique properties of the Piezoelectric Transformer (PT) based power supply (compact, low weight, high effi ciency) make it a perfect match for the DEAP technology.

The objective of the project is to develop a high voltage non-magnetic DC/DC PT based switch-mode power supply (SMPS), which enables the use of the DEAP technology as an actuator. The PT based SMPS has a huge potential compared to conventional magnetic based SMPS concerning mass production price, effi ciency, and size, but it is still a fairly novel technology.

The contributions of this project are: Finite element analysis (FEA), design, evaluation of zero voltage switching (ZVS) inductor-less PT based SMPS; self-oscillating control and bidirectional control of PT based inductor-less SMPS; the world’s fi rst bidirectional operation of a PT based SMPS.

Martin Schøler Rødgaard Completed: 2013 Project co-funded by Noliac A/S, Danfoss Polypower A/S and the Danish Advanced Technology Foundation

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Non-magnetic driver for piezo actuators

Piezoelectric Actuator Drive (PAD) aims to enable reliable motor performance in strong magnetic fi elds for MRI and CT treatment tables. There are technological limitations in operation of this motors and drive systems related to magnetic interference. PAD is the only form-fi t continuous drive solution currently available for the development of high performance non-magnetic motors.

This project will focus on the non-magnetic compact high effi ciency driver for the piezo actuators employing energy recovery from the capacitive actuators. Piezoelectric transformers are suitable candidates for addressing this challenge to provide solutions, which are far beyond any existing technology. The objectives would be achieved by imposing strict requirements on the driver design due to the direct energy feedback from the output side and allowing for precise control of the piezo actuators.

This project aims on compact and high effi ciency (above 90%) driver allowing for bidirectional current fl ow.

To be completed: 2015

Marzieh Ekthiari Project co-funded by IPU, Noliac A/S, Siemens Healthcare AG and the Danish Advanced Technology Foundation

Very high frequency switch-mode power supplies

When designing power converters it is always a goal to reduce the physical size, i.e. increase the power density. The development of Switch Mode Power Supplies (SMPS) made it possible to increase the power density signifi cantly, but it is limited by the size of the passive energy storing components (inductors and capacitors). The size of these, both numerically and physically, is however dependent on the switching frequency. Thus increasing the switching frequency will make it possible to reduce the size of SMPSs further.

In order to do keep the effi ciency high while increasing the switching frequency it will be investigated how resonant converters can be designed and controlled to minimize switching losses while keeping a wide control range.

Printed circuit board embedded magnetics and wide band gap MOSFETs will be investigated in order to reduce losses. Several control method and various topologies will be investigated in order to get the widest control range.

Especially applications where price, size and/or weight are crucial would benefi t from this technology. This could be chargers for portable devices, LED drivers and equipment for space.

Mickey P. Madsen To be completed: 2015

Project co-funded by Danfoss A/S, Grundfos A/S, KK-elektronics A/S, Vestas A/S and the Danish Advanced Technology Foundation

Radio frequency switch mode power supplies

Traditional SMPS are operated at frequencies ranging from 100 kHz – 1 MHz. By increasing the operating frequency, the physical size can be reduced until limited by losses in magnetic and switching components used in SMPS. The project is designed to investigate how the combination of VHF technology and control strategies from the fi eld of power electronics may be utilized in the design of power converters operating at VHF frequencies.

The goal of the project is to investigate and test feasibility of highly effi cient VHF DC/DC and AC/DC converters, operating in the frequency range of 30 MHz to 300 MHz. Pros and cons for using RF SMPS are sought clarifi ed. The investigation is expected to result in converters which are very effi cient, cheaper, have reduced physical size and EMI, and exhibit faster transient response compared to conventional designs.

RF converters can be made very small in size therefore may be integrated in all kinds of electronic equipment, and are especially attractive for high-volume applications with severe size constraints (LED drivers, battery chargers). In such applications the converter cost and size are of prime importance, and one of the key elements in this project is to investigate the usability of low-cost switching and passive components. Milovan Kovačević To be completed: 2014

Project co-funded by B&O A/S, International Rectifi er Denmark, Fairchild Semiconductor and the Ministry of Science, Innovation and Higher Education

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Low power high dynamic range A/D conversion channel

Low power operation is essential for modern digital MEMS microphones, but also high dynamic range has shown to be an important performance parameter. In a digital MEMS microphone an A/D conversion channel is implemented in the readout ASIC to create the digital output interface. However, the currently used topologies for the A/D conversion channel limit the dynamic range of the microphone system.

The primary objective of this research project is to investigate new alternative topologies for the A/D conversion channel, with the overall goal of improving the dynamic range of the digital MEMS microphone system. This will include research in the area of Delta-Sigma data converters for audio applications, and with a strong focus on low power mixed-signal ASIC design.

The results from this research project are expected to be used in the next generation of low power digital MEMS microphones.

To be completed: 2015

Niels Marker-Villumsen EPCOS AG, Industrial PhD

Design of digital audio class-D output-stage with feedback with emphasis on hearing-aid application

It is well known that the digitalization goes hand-in-hand with down-scaling dimensions of electronic devices. The back end of the audio system – DAC and power amplifi er – follows this trend as well as Class-D output stages merged with PWM and SD modulation DACs are commonly used today.

The project targets low-voltage low-power IC design of such back end. Its blocks highly infl uence the current consumption of the whole system. The consumption should be kept low to prolong the lifetime and to reduce the battery size of portable electronic devices. This project aims to implement the circuit with digital blocks, reducing the analog circuitry needed and to save power.

Novel interpolation fi lter structures and SD modulator confi gurations have been designed, simulated and implemented on FPGA for testing. The FPGA/VHDL design can be directly transferred to ASIC technology. Substantial reductions in complexity, hardware demands, clock rate and hence power consumption compared to previous state-of-art has been achieved by using new approaches to the design optimization. Peter Pracny To be completed: 2013

Project co-funded by Grosserer Alfred Nielsen og Hustrus Fond

Switch-mode drivers for incremental DEAP actuators

Conventional linear actuators whose actuation strokes are restricted to their initial geometrical dimensions, are limited in applications where large stroke, small size, light weight, fl exible structure and autonomous capability of the actuators are desired. Dielectric Electro Active Polymer (DEAP) based incremental actuator, compared to conventional ones is an alternative solution to overcome these limitations by providing an inchworm-like actuation.

High-voltage (~2.5 kV), high-power density, bi-directional, high effi cient, magnetic and piezo transformer based DC- DC converters as a driving mechanism for the DEAP incremental actuator will be researched and developed during this project. The driver electronics should be able to charge and discharge the diff erent parts of the incremental actuator. The ultimate goal is to make a compact high-voltage driver so that it can be integrated inside the incremental actuator.

The DEAP incremental actuators with several unique features will have a wide range of applications, compared to conventional piezo or pneumatics based incremental actuators.

To be completed: 2014

Prasanth Thummala Project co-funded by Danfoss Polypower A/S and the Danish Advanced Technology Foundation

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 High effi ciency reversible fuel cell power converter

Fuel cells (FCs) are an attractive environmental-friendly power source with large potentials in various applications, like distributed generations, hybrid electric vehicles and uninterruptible power supplies. Conventional FCs are suitable only for generating energy, but not for being used as energy storage elements. FCs based on new technology can operate in both modes and can provide high power density storage capability.

The project is researching, designing and optimizing FCs bi-directional dc-dc converters based on new Silicon Carbide (SiC) power devices for achieving high effi ciency, high frequency and high reliability for multi-kW range. The converter is tie to a dc-ac inverter and it allows the system to operate both as storage and as power source for the grid. Further optimization will improve dc-dc conversion effi ciency and FC system dynamics.

The project aims to develop high-effi ciency and high-energy-density reversible fuel cell dc-dc power converter based on SiC devices and with low manufacturing cost.

To be competed: 2014

Riccardo Pittini Project co-funded by Haldor Topsøe A/S, DONG Energy A/S, Dansk Gasteknisk Center A/S, EA Energianalyse A/S and The Danish Energy Agency

Piezoelectric transformer based power supply for DEAP

Dielectric Electro Active Polymer (DEAP) for use in applications such as surgical tools, grippers for material handling and valve actuators, works by charging the actuator to a high voltage (2.5kV). Conventional high voltage supplies are based on magnetic transformers, which prevent operation within high magnetic fi elds e.g. MR scanners. Size and effi ciency of conventional high voltage supplies are also limiting the growth of the DEAP technology. To extend the range of the DEAP technology, high voltage power supplies based on piezoelectric transformers (PT) are studied.

The aim is to increase effi ciency and miniaturize the overall size without using any magnetic components. This involves innovation within designs of high voltage PTs to increase the power density, and bidirectional topologies for reusing stored energy in the DEAP element and thereby improve the system effi ciency.

The new PT based bidirectional supply (non-magnetic, compact and high effi ciency,) make a perfect match for the DEAP technology and will insure new actuator solutions for industrial and consumer market.

Completed in 2012

Thomas Andersen Project co-funded by Noliac A/S, Danfoss Polypower A/S and the Danish Advanced Technology Foundation

High effi cient power factor correction (PFC) frontend for Class-D amplifi ers

Active Power Factor Correction (PFC) is widely used as a frontend to limit the AC line harmonic currents generated by switching mode power supplies in order to comply with the International Regulations. Nowadays, with the increasing global interest of energy saving, research on maximum attainable effi ciency has been of primary concern. Innovation of PFC technology obviously has signifi cant meaning for this issue.

The main challenge and objective of this project is to provide a high effi cient and high power density PFC frontend for high power Class-D amplifi ers. The study is focused on PFC’s topology improvement and magnetic optimization as well as investigation on methods for electromagnetic interference (EMI) suppression.

The contributions of this project are: A new interleaved bridgeless PFC; a design method for optimizing effi ciency, power density, and EMC; and a frequency dithering method to improve the EMC properties.

Completed: 2012

Project co-funded by B&O ICEpower A/S and the Ministry of Science, Innovation and Higher Education Qingan Li

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 HEARING SYSTEMS O centre willemploy 8PhD students and 4PostDocs. diff and visual of acousticboth cues exciting facilities. new labs isan thenew audiovisual Oneof immersion lab where able we willbe to simulate currently conducted at CAHR. centre, thenew As of part we willupgrade current lab facilities and build centre hearingnew research of ison fundamental and aspects will complement themore applied research stimuli and theimpact thishason listening incomplex, real-world situations. thefi Over fundamental questions regarding theinteraction of was theagreement with theOticon Founda Excellence for established Centre Hearing of newly (CHeSS). and Sciences Speech A major in2012 highlight A major our research of part isconducted at our Centre for Applied Hearing Research (CAHR)and the systems, hearing diagnostics tools and implants. cochlear and toprovide insights that for applications are technical useful suchashearing aids, recognition speech Th processing. Head of group: Professor Torsten Dau e goal of our research egoal of isto thehuman increase our thefunctioning understanding of auditory of system visual speech, audiology, th objective measures of ur group isconcerned with auditory signalprocessing and perception, perception, speech audio- erent rooms and spaces. With thissystem, to it possible examine willbe tion to create CHeSS thisnew centre. Th spatial hearing and theintegration audiovisual of e auditory and function hearing-instrument signal e research focus of the eresearch the of focus rst rst fi ve years, the years,ve the Currently, our group consists of 25 academic staff members (including 12 PhD students and 3 PostDocs). Our research has been supported mainly by grants from the Danish Research Council, the Danish hearing aid industry, private foundations, DTU, and the EU. Th e tools and facilities used for research and teaching include acoustically and electrically shielded testing booths, anechoic chambers, EEG recording systems, an otoacoustic emission recording system, an audiological clinic, a virtual auditory environment, and a master hearing-aid research platform.

Beyond our research, we also foster and support the education of engineers at both MSc and PhD level. Together with our colleagues in the Acoustic Technology group, we oﬀ er the international MSc “Engineering Acoustics” program. Many of the graduates of this program, who are interested in pursuing research, continue with our group as PhD students. Graduates have been well received by the national and international hearing-instrument industry and as postdocs at other prestigious universities. At our annual “CAHR presentation day”, many of our research projects are presented to our colleagues from industry and this event stimulates new projects and further collaboration.

We continue to develop international collaborations with other research centres. We are a member of the European Marie Curie Initial Training Network on “Investigating Speech Processing in Realistic Environments” (INSPIRE) that started in 2012. Another EU training network on “Improved Communication through Applied Hearing” (ICanHear) has been approved and will start in 2013. Th ese networks are particularly valuable and we expect that we will be able to continuously attract excellent researchers to our group both at junior and senior levels.

Furthermore, a grant proposal was submitted to the Oticon Foundation. Th e project aims at integrating current knowledge, concepts and techniques from speech production, psychoacoustics, brain and neuroimaging, speech perception, and computational modeling to tackle the so-called “cocktail party problem” in a novel way.

Our group also organized the 3rd “International Symposium on Audiological and Auditory Research” (ISAAR). Th e focus of this ISAAR was on speech perception and auditory disorders considered from diﬀ erent perspectives, including current physiological concepts of speech coding in the mammalian auditory system, perceptual measures of speech perception and processing, novel paradigms to measure consequences of hearing impairment, state-of-the-art auditory processing models of complex sounds, as well as implications for new technical applications. Th e corresponding conference proceedings book is in press.

Computational auditory scene analysis based on a model of human binaural processing

Computational auditory scene analysis is a fi eld of hearing science that models how the human auditory system parses an acoustic scene. The approach is to combine various acoustic and perceptual cues and determine their relative importance in the perception of an acoustic scene, such as evaluating the direction of a sound source.

This project focuses on predicting speech intelligibility in realistic environments. The aim is to extend a monaural model of speech intelligibility to the binaural domain. The binaural model is fi rst evaluated for normal-hearing listeners and later combined with a model of impaired hearing to establish a general framework for testing the eff ect of hearing-aid signal processing on speech intelligibility in realistic environments.

A model of speech intelligibility may help investigating the critical cues for speech understanding in adverse everyday environments, such as train stations and public spaces.

To be completed: 2015 Alexandre Chabot-Leclerc Project co-funded by Phonak

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Investigation of release from masking in normal-hearing and hearing-impaired listeners

People with normal hearing typically show a signifi cant increase in speech recognition when a constant background noise is replaced with a fl uctuating noise. In contrast, people with impaired hearing often show very little benefi t from gaps in the noise. It has been hypothesized that certain functions in the auditory system are specifi cally related to listening in the gaps of a fl uctuating noise and that these are degraded in the impaired system.

This project investigates if there are functions in the auditory system that are specifi cally used for listening in the gaps and responsible for the reduced benefi t for hearing-impaired people or if it is just a consequence of their reduced speech recognition in general. Furthermore, a model of the auditory system is used to investigate how the diff erent auditory functions aff ect the ability to listen in the gaps.

Identifying the defi cits in the auditory system responsible for reduced speech recognition in noise and the benefi t of gaps in the noise, can help to make hearing aids that compensate for these defi cits.

Claus Christiansen Completed: 2012 Project co-funded by Oticon A/S, Widex A/S and GN Resound A/S

Pitch representations in the impaired auditory system and implications for music perception

It is well established that hearing loss aff ects the ability of listeners to perceive pitch, the attribute of hearing which allows us to hear sounds as musical. The current diffi culties in conveying accurate pitch information to hearing- impaired listeners are largely due to a lack of knowledge about the underlying mechanisms, in terms of the neural representation and coding of pitch, and the perceptual consequences of pitch-evoking sounds.

In this project, hearing-impaired subjects will participate in both behavioral and objective measures of pitch-perception. The outcomes of the behavioral experiments will be compared to objective measures of brain activation obtained via functional magnetic-resonance imaging (fMRI) techniques. The aim is to investigate how diff erent abilities in spectral and temporal resolution are refl ected at a cortical level.

Understanding the underlying mechanisms of pitch coding is a crucial step towards restoring accurate pitch perception in hearing-impaired subjects by the means of hearing devices.

Federica Bianchi To be completed: 2015 Project funded by DTU

Modeling human auditory-evoked brain responses to complex

When sounds are presented to human subjects, it is possible to record auditory evoked-potentials (AEPs) on the surface of the scalp. AEPs can be used as an objective tool to assess hearing defi ciency, for example in newborn screening. There is, however, a lack of knowledge about how hearing defi ciencies aff ect AEP formation.

The aim of this PhD project is to build a model capable of simulating AEPs based on current knowledge of neural auditory signal processing. The model shall be able to simulate AEPs in response to a wide variety of stimuli of varying duration and bandwidth.

The developed AEP model allows the design of new hypotheses and experimental tests in a research context. In a clinical setting, the model can inspire the development of optimized stimuli for diagnostics. Finally, the modeling framework will be useful for the objective evaluation of hearing-aid fi tting.

Completed: 2012

Project co-funded by Oticon A/S, Widex A/S and GN Resound A/S Filip Munch Rønne

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Characterization and prediction of the perceptual consequences of individual hearing loss

Traditionally, hearing aids are fi tted based on an individual’s audiogram, a simple measure of absolute sensitivity to tones of diff erent frequencies. However, the performance of listeners fi tted with hearing aids can vary enormously across individuals, since other processing defi cits signifi cantly infl uence an individual’s ability to understand speech in diffi cult conditions.

The goal of this project is the development of an auditory profi le that characterizes an individual’s hearing loss by measuring diff erent aspects of auditory processing (e.g., sensitivity, amplitude compression, cognitive capacities, etc.). Once developed, we will characterize the relationship between the individuals’ auditory profi le and their ability to process speech in a variety of situations.

The results of this project are expected to have substantial practical relevance in the development of hearing instruments, and clinical importance in evaluation and fi tting of hearing aids.

Gusztáv Lőcsei To be completed: 2015 Project co-funded by the EU

Distance perception in impaired and aided-impaired hearing

Natural sound sources in our environment are usually perceived as clearly externalized and are thus properly localized both in terms of direction and distance. A variety of auditory cues arising from the location dependent fi ltering of the signals at the two ears and the ratio of direct to reverberant sound are thought to contribute to this process. However, these cues can be disturbed by hearing aids, and thereby degrade the spatial image perception.

The goal of this project is to explore the relative importance of the key signal features and auditory mechanisms involved in distance perception and externalization for normal hearing and hearing impaired listeners. Furthermore, the project investigates the impact of hearing instrument signal processing strategies on the perception of externalization.

The results may be important for development of improved signal processing algorithms for hearing aids aimed at preserving a natural spatial sound perception.

To be completed: 2013

Jasmina Catic Project co-funded by Oticon A/S, Widex A/S and GN Resound A/S

Sound fi eld control via perceptual cues

Modern audio reproduction systems are used in various applications, such as virtual sound environments and teleconference systems. One of the challenges is to correctly capture and reproduce room acoustical features of complex acoustic scenarios. Since always human listeners are the users of such systems, perceptual aspects in this context are very important.

This project investigates the perception of room acoustical properties in complex scenes. The aim is to correlate physical cues that are available to a human listener to the listener’s perception. In particular, the observed consistency in perception will be investigated which is not refl ected in corresponding physical measures. Based on a modifi ed binaural auditory model, the auditory processes underlying the perception of complex auditory scenes will be analysed.

The results will be used to design appropriate strategies for (active) sound fi eld control with loudspeaker-based systems. The goal is to include perceptual aspects in common sound fi eld control strategies.

To be completed: 2014 Johannes Käsbach Project co-funded by Oticon A/S, Widex A/S and GN Resound A/S

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Modeling the consequences of hearing loss and hearing-aid processing on consonant perception

Speech consists of consecutive units such as consonants and vowels which convey important information on a “short-term” scale. One of the challenges of current hearing research is to understand how these short-term acoustic features are related to human speech perception. This has traditionally been studied in terms of confusions between consonants in various adverse conditions, e.g. in noise, with spectral limitation or degradation.

This project aims at developing a consistent modeling framework that predicts consonant confusions made by normal-hearing and hearing-impaired listeners based on the acoustic stimuli. Furthermore, the eff ects of hearing-aid processing on consonant perception will be investigated. To do so, the important cues that lead to a specifi c percept are to be identifi ed in terms of the spectral energy and modulation energy distributions.

Understanding the physical correlates of short-term speech perception and how they are aff ected by auditory defi cits can have substantial relevance for hearing-aid development.

Johannes Zaar To be completed: 2015 Project co-funded by the EU

Characterizing human auditory processing in reverberant environments with multiple sound sources

A major challenge in current auditory research is to solve the so-called “cocktail party problem” that describes the substantial diffi culty most hearing-impaired listeners have in understanding speech in complex acoustic environments. Normal-hearing listeners on the other hand can almost eff ortlessly decode the acoustic scene with a performance currently unmatched by state-of-the-art technical systems.

This project focuses on creating realistic acoustic scenarios around the listener in a laboratory setting, using microphone array recordings and a loudspeaker-based virtual auditory environment. In this way, the ability of both normal-hearing and hearing impaired listeners to perceptually organize sound in various scenarios can be investigated in a controlled manner. The benefi t of diff erent hearing aid processing algorithms can also be evaluated.

The results of the project are expected to shed light on the auditory system’s processing strategies in challenging environments, and might ultimately enable the development of newer, “smarter” hearing aids.

Marton Marschall To be completed: 2013 Project co-funded by Siemens Audiologische Technik

Individualized hearing aid fi tting based on behavioral estimates of the inner-ear input/output function

It is estimated that 250 million people are hearing impaired and this number is growing. Modern integrated circuit technology has allowed for compensation for hearing loss by means of digital hearing aids. These are small and eff ective while keeping the energy consumption low. However, multiple fi tting sessions are usually required in order to obtain high user satisfaction. One of the limitations is the way the hearing devices are adjusted to the user.

In this project, time-effi cient experiments will be designed that measure audibility and temporal resolution at various frequencies. The specifi c design allows the behavioural estimation of the amount of compression of the inner-ear’s (cochlear) input/output function for a given stimulus frequency, as well as the estimation of the function’s knee-point between linear and compressive processing. The results will provide more detailed information about the state of the inner ear than previously considered measures.

This work will form the basis for new, more individualized, fi tting rationales that will improve the quality and effi ciency of the fi rst hearing-aid fi tting. The project will also be important for the modelling of the perceptual consequences of Michal Fereczkowski diff erent types of cochlear hearing loss.

To be completed in 2014

Project co-funded by Oticon A/S, Widex A/S and GN Resound A/S

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Speech intelligibility improvement using modern envelope and phase manipulations

Temporal and spectral modulations embedded in speech are known to play a very signifi cant role for speech intelligibility, especially in noisy conditions. It is therefore plausible to foresee an improvement in speech intelligibility when well-chosen manipulations of its modulation content are achieved. However modulation extraction and modifi cation is a largely non-linear problem, which in most cases does not have an exact solution.

In this project a novel approach to the problem is devised. Based on modifi ed spectrogram reconstruction using an optimization algorithm, it takes into account psycho-acoustical parameters, allowing for a better accuracy of the modulation manipulations and a better sound quality of the output than existing methods. From this, psycho- acoustical experiments will be run to assess the infl uence of modulations in speech intelligibility.

An effi cient tool to manipulate spectro-temporal modulations in speech would open many opportunities in the community for studying their role and how they are perceived.

Rémi Decorsière To be completed: 2013 Project co-funded by the Oticon Foundation

Temporal coherence in the perceptual organization of auditory scenes

One of the most fascinating capabilities of the human auditory system is its ability to robustly segregate sound sources in complex acoustic scenes. This allows us to selectively attend to a single sound source and to some extent ignore the competing acoustic information present at the same time. However, this ability is often reduced in hearing- impaired listeners, making it diffi cult to e.g. follow a conversation in a crowded room.

In this project, a model of auditory stream segregation is developed and evaluated. The model is based on a physiologically inspired model of the auditory periphery, combined with a temporal coherence analysis as the primary criterion for predicting stream formation. Parallel to the modelling part of the project, experimental work is carried out to quantify the relative infl uence of diff erent streaming cues on normal-hearing and hearing-impaired listeners.

Modelling stream segregation may help us to understand how we perceptually segregate sound sources and, in turn, why this is particularly diffi cult for the hearing impaired.

To be completed: 2014

Simon Krogholt Christiansen Project co-funded by the Oticon Foundation

Predicting the intelligibility of processed noisy speech based on the signal-to- noise ratio in the modulation domain

Speech intelligibility represents a measure of how well people understand speech in a given environment, e.g. in a lecture room, over the telephone or when using a hearing-aid. Current models for predicting speech intelligibility are successful when predicting eff ects of linear distortions such as noise and reverberation, but fail to accurately predict the eff ects of non-linear signal processing and noise reduction.

This project investigates a new approach that predicts the eff ect of linear and non-linear distortions on speech intelligibility using a functional signal processing-model of the human auditory system. The model is evaluated for normal-hearing listeners by comparing model predictions with psychoacoustic data measured in a broad range of conditions.

Accurate prediction of speech intelligibility in a wide range of conditions will greatly benefi t the development and evaluation of hearing-aid signal processing algorithms.

Søren Jørgensen To be completed: 2013 Project co-funded by Oticon A/S, Widex A/S and GN Resound A/S

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Facts and fi gures

Income 2011 2012* Expenses 2011 2012

External funds 65.814 71.693 Salaries 81.851 100.572 Industrial/commercial 4.676 1.894 Operational costs 22.320 22.857 DTU funding 70.074 72.476 Transfers & overhead 22.332 10.176 Investments in facilities 13.368 7.909 Total 140.564 146.603 Total 139.871 141.514 * 2012 fi gures include our activities at Risø campus.

120,000

80,000

75,000 60,000 45,000 40,000 30,000 in 1000 DKK in 1000 DKK 15,000 0 0 External funds Industrial/commercial DTU funding Salaries Operational Transfers & Investments costs overhead in facilities

Total staff * 2011 2012 Education 2011 2012

Faculty staff 51 52 Graduated MScEE 103 104 Externally fi nanced 35 45 Graduated BEng 30 36 PhD students 67 72 Student f.t.e.*(value added) 380 391 Tech/Adm staff 46 53

Total 199 222 * f.t.e.=full time equivalent (årsværk)

* f.t.e.=full time equivalent (årsværk)

50 450

30 300

20 150 10 full time equivalent 0 0 Faculty staff Externally PhD Tech/Adm Graduated Graduated Student financed students staff MScEE BEng f.t.e.*(value added)

2011 2012

DTU ELECTRICAL ENGINEERING IN PROFILE 2013 Advisory board

Birgitte Brinch Madsen, Chief Technical Oﬃ cer Maersk FPSOs

Peter Petersen, Management Consultant

Poul Toft Frederiksen, Senior Science Advisor Grundfos A/S

Søren Westermann, Executive Vice President Widex A/S

Management Publications

Professor Kristian Stubkjær 2012 research data in numbers Head of Department ISI registered journal papers 105

Professor Michael A.E. Andersen Non ISI registered journal papers 23 Deputy Head of Department Conference papers published in books/proceedings 229 Head of Electronics Chapters in books 16 Monographs 1 Associate Professor Finn Jacobsen Reports 8 Head of Acoustic Technology PhD theses 11 Associate Professor Ole Ravn MSc theses 104 Head of Automation and Control BSc theses 47 BEng theses 36 Professor Jens E.Wilhjelm Inventions w. commercial potential 11 Head of Biomedical Engineering

Professor Jacob Østergaard Head of Center for Electric Power and Energy You may search for DTU Electrical Engineering’s publications in DTU’s online research database, ORBIT. Associate Professor Joachim Holbøll Deputy Head of Center for Electric Power and Energy Website: http://orbit.dtu.dk

Professor Olav Breinbjerg Head of Electromagnetic Systems

Professor Torsten Dau Links Head of Hearing Systems For further information about DTU Electrical Engineering, you are welcome to visit our website. Here you will also Professor Erik Bruun ﬁ nd our News and Calendar containing daily updated Chairman of the DTU Electrical Engineering Study information about our events and achievements. Committee Danish website: www.elektro.dtu.dk English website: www.elektro.dtu.dk/english

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DTU ELECTRICAL ENGINEERING IN PROFILE 2013