A Century of ABB Review

W ABB 2 |14 review en 100 years of ABB Review 7 40 years in robotics 24 60 years of HVDC 33 Boundaries of knowledge 68 The corporate technical journal

A century of ABB Review Dear Reader, Technological innovation has been the cornerstone of ABB’s success since the founding of our predecessor companies in the late 19th century.

Today, we invest $1.5 billion each year in R&D and we have 8,500 technologists focused on power and automation innovations around the world.

For 100 years, ABB Review has been keeping our shareholders, customers and employees informed about our innovative solutions and achievements in the areas of power and automation.

Just like ABB, ABB Review is continually innovating in terms of content and design.

The next phase of ABB Review will be to strengthen its presence online to meet the oppor- tunities and demands of the digital world, for instance through more interactive communication.

We are proud to share our centenary issue with you.

Ulrich Spiesshofer Chief Executive Officer ABB Group

2 ABB review 2|14 Contents

7 100 years of ABB Review Centenary Looking back on a century in print

21 Editors’ picks celebration Treasures from the archives

24 Rise of the robot Perpetual Celebrating 40 years of industrial robotics at ABB

33 60 years of HVDC Pioneering ABB’s road from pioneer to market leader

42 Pumping efficiency Knowledge to A 100 MW converter for the Grimsel 2 pumped storage plant power 48 Unit of power Cutting-edge motor design redefines power density

54 Multitalented ACS800 power electronics can do more than rotate a motor

58 Hot spot Power A new infrared sensor measures temperature in generator circuit breakers is knowledge 65 At a higher level A medium-voltage-level UPS for complete power protection

68 Boundaries of knowledge Knowledge of boundary conditions is crucial for reliable simulations

74 Pushing the limits Turbine simulation for next-generation turbochargers

Contents 3 Editorial 100 years of ABB Review

Dear Reader, History often holds the key to understanding taking up the IRB 6’s anthropomorphic the present. Its study can at times humblingly configuration. reveal that ideas we erroneously classify as recent have been around for much longer Sixty years ago, ASEA delivered the world’s first than we imagine. On the other hand it can commercial HVDC link, transmitting power from upliftingly remind us how quickly break- the Swedish mainland to the island of Gotland. throughs can totally transform large parts The line delivered 20 MW over 98 km at 100 kV. of the industry. These figures may appear but small fry compared to later HVDC projects, but this pioneer- 2014 is a year of several landmark anniversa- ing link was trendsetting in more respects than ries for ABB. As you have probably gathered one: Its underwater cables, for example, also Claes Rytoft from the cover of this edition, ABB Review is introduced concepts still valid today. 100 years old this year. We are marking the anniversary by dedicating an entire section to Both of these anniversaries are covered by the centenary (and are also planning other dedicated articles in this issue. events during the course of 2014). Further articles cover trends in fields as varied A single issue of ABB Review is insufficient as pumped storage, motor design, power to even skim the surface of the wealth of electronics, sensors, UPS and simulation. material available in the archives. We hope, nevertheless, that our small selection will give I trust that this anniversary edition of ABB you a taste of the breadth of development Review with its insights of past, present and the journal witnessed in its long history. For future developments will inspire you (as it did reasons of space, even these few selected us) in the discovery and rediscovery of both articles had to be shortened in the print known and unknown sides of ABB. edition, but readers of the tablet version of can enjoy them in full length. Enjoy your reading.

The two other great anniversaries of this year relate to robotics and HVDC. Forty years ago, in 1974, ASEA launched the IRB 6, the world’s first commercially available Claes Rytoft microprocessor-controlled and all-electric Chief Technology Officer and robot. Virtually all industrial robots in use Group Senior Vice President today fall into this category while also ABB Group

4 ABB review 2|14 Contents

7 100 years of ABB Review Centenary Looking back on a century in print

21 Editors’ picks celebration Each of the members of the ABB Review team picks an article and presents it to the reader.

24 Rise of the robot Perpetual Celebrating 40 years of industrial robotics at ABB

33 60 years of HVDC Pioneering ABB’s road from pioneer to market leader

42 Pumping efficiency Knowledge to A 100 MW converter for the Grimsel 2 pump storage plant power 48 Unit of power Cutting-edge motor design redefines power density

54 Multitalented ACS800 power electronics can do more than rotate a motor

58 Hot spot Power A new infrared sensor measures tempera¬ture in generator circuit breakers is knowledge 65 At a higher level A medium-voltage level UPS for complete power protection

68 Boundaries of knowledge Knowledge of boundary conditions is crucial for reliable simulations

74 Pushing the limits Turbine simulation for next-generation turbochargers

The cover of the first ever edition of ABB Review appears on page 6 of this centenary edition. The present spread uses the cover picture of the second edition (August–September 1914) depicting the spinning mill in Fouchy (Alsace). The equipment was driven by 57 Brown Boveri motors.

Editorial 5 6 ABB review 2|14 100 years of ABB Review

Looking back on a century in print

ANDREAS MOGLESTUE – History is BB Review’s predecessor jour- Over the last 100 years, the pages of more than the recording of chronology. nal, BBC Review 1, was first ABB Review have featured a staggering Although the great milestones of published in July 1914. Its ini- number of contributions on a broad range political change, of wars and of A tial purpose was to inform of subjects. Some articles covered the landmark achievements may form sales agents and business partners of predecessors of products still manufac- the skeletal backbone of history, what the company’s products, developments tured by ABB. Many of the statements breathes life and context into our and activities. In later years, distribution made in these articles are still surpris- understanding of the past are the grew to encompass a broader reader- ingly valid today. Other contributions re- smaller events that are handed down to ship including customers and suppliers, flect developments that were not pursued us: the memories, photographs, facts consultants and journalists as well as further by the company or that devel- about everyday life and objects that universities, educators, students and lay oped in a different way than expected. each tell a story. Much of the great people with an interest in technology. fascination in looking back over ABB Many engineers who later came to work Besides documenting this progress, the Review’s 100 years lies in the latter. for ABB began to read ABB Review in archives also present other insights. The their student days and were inspired in style of publication has clearly developed their career choice by the company’s over time – not just in terms of the devel- technological prowess. Similarly, many opment of typography, the gradual intro- trade journals regularly publish articles

that were first seen on the pages of ABB Title picture Review, and illustrations and diagrams This was the cover of the first-ever edition of BBC from its pages have been republished in Review. The photograph depicts the Swiss National 1914 university text books. Part of the jour- Exhibition held between May and October 1914 in Bern (Switzerland). nal’s appeal lies in its aim to be as objective as possible: Although it clearly speaks from an ABB perspective, ABB Review Footnote 1 Although BBC’s full name was “Brown, Boveri & strives to remain factual and unbiased in Company,” the journal was spelled wihout the the claims it makes. comma – The Brown Boveri Review.

1914 BBC Panama 1921 1922 Review Canal is published officially Women Insulin for the first opened achieve hormone is time 1918 equal voting isolated by 1923 rights in Sir Frederick Reader’s Digest First Sweden Grant Banting is launched publication of TIME magazine

100 years of ABB Review 7 duction of color photographs or ques- had its own publication, ASEA Journal. mat and more advanced tablet versions tions of style or presentation, but also in The latter was some years older than for iOS and Android. the manner in which articles are present- BBC Review, having first appeared in ed. Early issues make more liberal use of 1909. The company merger also led to Space constraints mean that the histori- mathematical proofs, detailed circuit dia- a merging of the two editorial offices cal clippings presented in the following grams and construction drawings than is and ABB Review builds on the tradi- pages must appear in a much abridged the case today. This may on the one hand tions of both predecessor journals. form in the print and pdf versions. The be driven by concerns over the need to tablet version contains more extensive protect intellectual property, but also by Today, ABB Review is distributed to versions of some of the items. changed reader expectations and subtle more than countries and published in changes in the positioning of the journal. five languages. Almost 60,000 copies Andreas Moglestue of every edition are printed. There is Chief Editor, ABB Review BBC’s sister company, ASEA (with furthermore a growing electronic distri- Zurich, Switzerland which it merged in 1988 to form ABB) bution, both using a “classical” pdf for- [email protected]

Remembering the founders Charles Eugene Lancelot Brown and Walter Boveri jointly founded BBC on October 2, 1891. Although both men came from an engineering background, Boveri grew increasingly active in the stewardship and growth of the company whereas Brown continued to focus on engineering challenges. Their names are remembered today in the two Bs of ABB. Both men passed away in 1924. As far as the editorial team can ascertain, theirs were the only obituaries ever to have been published on the pages of this journal.

The founders of ASEA, Ludwig Fredholm and Jonas Wenström passed away in 1891 and 1893 respectively, before the birth of the ASEA Journal.

1924

1928 1935

Flying First night Doctor game in service Major League starts in Baseball made Australia possible by 1924 1925 1931 electric lighting Death of Death of John Logie Opening of Charles E.L. Walter Boveri, Baird the Empire Brown, cofounder demon- State cofounder of BBC strates Building in of BBC television New York First winter Olympics

8 ABB review 2|14 The Hollerith machine The Hollerith classification system permitted the automatic compilation of statistics. Data were stored by punching holes in cards. Counters were triggered by electrical connections. Herman Hollerith’s machines were used in the 1890 US census, permitting the counting to be com pleted in a year (the previous 1880 census had taken eight years). The Hollerith machine can be considered an early computer.

Hollerith’s invention was initially patented, but because of its universal significance in improving the handling of data, the US government removed this restriction in 1910. BBC was one of the companies to benefit from this.

Punched cards were first introduced in the 18th century and used to “program” textile looms and musical machines. Later they were used for data storage and the programming of computers.

It is interesting to observe that today’s DVDs still rely on microscopic holes to store data.

The Brown Boveri Review, November – December 1914

Throughout its long history, ABB has equipped countless power plants, many of which are still generating electricity today. This one is in Peru’s Santa Eulalia Valley.

The Brown Boveri Review, October 1939

100 years of ABB Review 9 A century of hum

A trio of BBC transformers are the same age as ABB Review

SALLY DURRANT – They started service before the invention of the toaster, the TV and the Internet. Qantas and Canberra weren’t even born yet. And two world wars, the Beatles, Britney Spears, Monty Python, spaceflight, penicillin and Velcro also impacted our world for better or worse over those years.

So what has withstood the test of time?

Three ABB power transformers have been stalwarts in the rural Victorian landscape of Australia for the last 100 years, actively doing their business for local utility SP AusNet. The trans formers were part of a zone substation supplying the local area which also included two hydrogeneration companies.

SP AusNet’s Project Manager for Capital Delivery and Engineering, Neil Sequeira agreed. “These ABB transformers were way over engineered and built to last,” he said. The only loving care they seemed to require was to feed their thirst for oil. Well you wouldn’t deny a 100-year-old a drink every now and then! Happy 100th birthday transformer 1, 2 and 3. May you enjoy your The three grand old dames (or gents, well-deserved retirement! depending on your point of view) are being retired not because they aren’t pulling their weight, but because the SP AusNet substation is being rebuilt. One of the transformers will be shipped to ABB’s Moorebank, Sydney facility where it will live out its twilight years under the shade of a gum tree as part of Sally Durrant a display of old and new – a testament Moorebank, Australia to the great technology ABB continues ABB Corporate Communications The three 9 MVA 22/66 kV GSU transformers are to invent and reinvent. [email protected] just as old as ABB Review. They were supplied by BBC in 1914.

10 ABB review 2|14 Drying grass to make winter fodder for cattle? And that using electricity? ABB Review has no shortage of articles on unusual applications.

The Brown Boveri Review Review, April/May 1941

1942

1938

Chester 1937 Carlson 1939 invents a 1943 BBC BBC Nylon, dry demon builds the BBC builds invented by printing strates the first the first Wallace process first combus 110 kV Carothers, called transmis tion gas high-speed is patented electropho- sion of turbine for air-blast tography, HVDC generating circuit commonly (Wettingen electricity breaker called a to Zürich) 1942 Xerox Gagnan and Cousteau devise the scuba aqualung

100 years of ABB Review 11 The wristwatch connection

BBC’s contribution to the LCD

ANDREAS MOGLESTUE – ABB and its its intermediate phase. He hence was opened in Lenzburg (Switzerland). forerunner companies have never dubbed it a “liquid crystal.” It was expanded to 4,370 m2 in 1978. been shy to break new ground and pioneer new technologies. Some of In 1962, Richard Williams of the Radio The compact size and low power these escapades have taken the Corporation of America (RCA) showed consumption of the displays made them company well outside its usual market that the alignment of liquid crystals ideal for wristwatches. In the early years, segment. At times, BBC was in the of p-azoxyanisole could be influenced BBC collaborated with several small- market for such devices as domestic by electric fields. His RCA colleague, volume Swiss watchmakers, but the real ovens, fridges and floor-polishing George Heilmeier, made this realign- breakthrough came when CASIO was machines. It was also once at the ment visible through the use of dyes, brought onboard. The innovative heart of a fashionable wristwatch. paving the way for LCDs. In circa 1968, Casiotron wristwatch that was launched Sharp com- in 1974 used a BBC LCD. The Casiotron menced research was not only the first LCD watch to be in the area, recog- produced in large numbers, but also the nizing the technol- first with a built-in calendar (even taking ogy’s potential for into account leap years). calculator displays. The first such In later years, BBC added the backlight- calculator was ing concept that is still used for LCDs launched in 1973. today. In 1983, the company invented the super-twisted nematic LCD, repre- In 1969, BBC senting another great leap forward in began a joint terms of the crispness of the display research effort and resolution. This technology was with Hoffmann used in the Nintendo Game Boy and La Roche. Initially early mobile phones. BBC benefitted this was based from this mostly through patent income in BBC’s research as the company’s own production was center in Dättwil already being ramped down. The facility Prototype of a patented passive-matrix super-twisted nematic LCD with 540 × 270 pixels (Switzerland), in Lenzburg is today a center of power which had been semiconductor manufacturing. Today, the concept of a digital watch is inaugurated two years previously. The mostly associated with the 1980s era. research effort soon bore first fruits, Andreas Moglestue It is easily overlooked that the concept with Wolfgang Helfrich and Martin ABB Review of the liquid crystal display (LCD) is Schadt patenting the twisted nematic Zurich, Switzerland much older. The Austrian botanist, Fried- field effect in the following year. Cells [email protected] rich Reinitzer, is generally credited with using this effect displayed a greater having first observed (in 1888) a material sharpness and lower power consump- Further reading displaying a curious intermediate state tion than previous LCDs. Hoffmann H. Kawamoto, “The History of Liquid-Crystal between solid and liquid. He shared his La Roche withdrew from the collaboration Displays,” Proceedings of the IEEE, vol. 90, no. 4, observation with the German physicist, in 1972, but BBC continued developing pp. 460–500, Apr. 2002. Otto Lehmann, who investigated it the technology. A first production line P. J. Wild, First-Hand: Liquid Crystal Display Evolution – Swiss Contributions, further. Lehmann noticed that the was set up in BBC’s tube factory at http://www.ieeeghn.org/wiki/index.php/First- substance (cholesteryl benzoate) had Birrfeld (Switzerland) in 1973. The Hand:Liquid_Crystal_Display_Evolution_-_Swiss_ the refractive qualities of a crystal during following year, an entirely new factory Contributions

12 ABB review 2|14 What we today call electromobility is no new field for ABB.

The Brown Boveri Review, January/February/March 1942

Moving transformers in 1908 (above) and 1937 (left)

The Brown Boveri Review, November/December 1942

1944 1946 1951

1945

George Orwell publishes Animal 1947 Farm The transistor is invented 1944 1946 by Bardeen, 1951 Brattain, BBC develops Disposable and First BBC the first high- diapers Shockley Review speed locomo are invented cover in tive with a direct by Marion color drive system Donovan

100 years of ABB Review 13 The arguments for using DC transmission to integrate renewable generation are far from new, as this 1945 contribution shows.

Despite BBC’s early activities, it was the ASEA side of the company that established early leadership in the field of HVDC (see also page 33 of this edition of ABB Review).

The Brown Boveri Review, September 1945

1954

1953 ASEA is the first 1960 1961 company in the Theodore Bob Dylan world to Maiman makes his manufac invents the debut ture laser perfor- synthetic mance in diamonds Greenwich Village, 1952 1954 New York

Jonas Salk ASEA develops a lays the vaccine first-ever against commer poliomyelitis cial HVDC (polio) transmis sion line

14 ABB review 2|14 There’s nothing new about using refuse as a fuel.

Brown Boveri Review, July 1969

Long before MATLABTM was invented, ABB Review was already using 3-D depictions to present results.

The Brown Boveri Review, October 1946

1964

1962 1967 The audio Rachel Carson First cassette is publishes calculator is invented Silent Spring, invented frequently cited as being one of the key 1968 catalysts that inspired the Douglas environmental 1964 1965 Engelbart movement demonstrates the BASIC is Compact world’s first invented by disc is computer John George invented by mouse Kemeny and James Tom Kurtz Russell

100 years of ABB Review 15 Installing power equipment in northern Canada sometimes called for unconventional methods.

The Brown Boveri Review, July/August 1955

Radio equipment for the Parisian police.

The Brown Boveri Review, January/February 1949

1974 1975

1969 BBC develops the first gearless cement drive 1971 1974 1975

Women Erno ASEA launches Digital achieve Rubik gives one of the camera 1976 equal voting the world world’s first invented by rights in the Rubik’s electrical in Steve Inkjet Switzerland cube dustrial robots Sasson printer is of Kodak invented

16 ABB review 2|14 100 years of ABB Review 17 Control room of a hydroelectric power plant in Italy. ABB still equips control rooms today – although today’s equivalent looks very different.

The Brown Boveri Review, January 1955

Manhauling equipment on sleds for the La Dôle television transmitter, Switzerland.

The Brown Boveri Review, March 1955

1984 1987 1991

1990 ABB launches the Azipod® electric propulsion system for 1978 ships 1991

First IVF First ABB baby is Review in born 1987 1988 Russian First BBC ASEA and Stephen Review in BBC Hawking Spanish merge publishes to create A Brief ABB History of Time

18 ABB review 2|14 ABB drives can take your car for a test drive.

Brown Boveri Review, March 1986

In 1988, ASEA and ABB merged to form ABB. But this was far from the first cooperation between the two companies. As this article documents, The companies collaborated in a project to create an HVDC breaker during the 1970s.

ASEA Journal, vol. 48, no. 3, 1975

1994 2003

1998 2001 World’s First full Apple longest Web launches (1,990 m) presence the iPod suspension of ABB bridge, the Review 1997 Akashi 2002 Deep Blue Kaikyo, ABB links computer opens in the AC defeats Japan networks 2003 of South world chess First champion Australia and Victoria with ABB Gary Review in Kasparov the world’s longest Chinese underground transmission

100 years of ABB Review 19 BBC supplied the motors, circuit breakers and regulators for this 3 kV DC, 1,00 hp locomotive headed for Brazil in 1955. BBC has since its early days been a supplier to the railway industry, and still is today.

The Brown Boveri Review, January 1955

Maybe BBC technology helped sort your airline luggage!

Brown Boveri Review, May 1986

ABB 2|10 The corporate ABB technical journal Review

The corporate technical journal of the ABB Group review www.abb.com/abbreview National and railway grids connect 42 2008 Traction motors 66 2010 2013 Service for the rail industry 70 Recharging electric cars 77

Railways and transportation

ABB in China page 5

Powering the economy Special Report page 16 Productivity Dancing page 47 Robotics with the Dragon page 82

a 2012

ABB successfully 2008 designs and 2013 develops a World’s ABB hybrid DC Review tallest 2009 2010 breaker Ferris made Usain Bolt suitable for wheel, ABB opens available sets a new the creation Singapore the world’s in e-reader men’s of large Flyer, highest format 100 m inter- opens in substation in sprint regional DC Singapore the world’s grids record of tallest build 9.58 s ing, the Burj Khalifa, in the UAE

20 ABB review 2|14 Editors’ picks Treasures from the archives

Sarah Stoeter has a BA in Clearing the rails English and Psychology from the University of Minnesota in the United States. She has been an editor for ABB Review E. Hugentobler, (G.A.W.), “Electric rotary snow-plough SARAH STOETER – If you’re reading this since 2007. for the Ribas Nuria mountain railway in Spain,” journal, you are probably already well [email protected] The Brown Boveri Review, pp. 63–65, Feb. 1932. acquainted with ABB’s countless power and automation technologies – indus trial motors and drives, transformers, switchgear, robots, controllers, ship propulsion units, HVDC, and automa tion systems, to name but a few. But would you believe that, at one time, ABB made snow plows? This interest ing twist in the company’s history demonstrates to me the innovative spirit that is very much a part of ABB today. As an editor, it is a privilege to be able to help shape articles about technologies such as this one, to be part of ABB’s innovative spirit.

ABB’s predecessor companies, ASEA and BBC, both manufactured locomotives and were instrumental in the electrification of numerous railways particularly in Sweden and Switzerland. The electric rotary snow plow for locomotives, described in the 1932 Brown Boveri Review article “Electric Rotary Snow-Plough for the Ribas Nuria mountain railway in Spain,” nicely complements the rail element of ABB’s past.

A 12.2 km long railway, climbing 1,055 m from its valley station in Ribes de Fresser (Ribas) to Vall de Núria in the Pyrenees mountains at an altitude of 1,960 m above sea level, serviced an area “much visited for pilgrimages, altitude cures, mountain tours and winter sports” – a journey, which, in winter, would not be possible without a viable means of clearing heavy snow off the tracks. This was the impetus for the electric-rotary snow plow developed by BBC and SLM, which was put into service in 1931.

100 years of ABB Review 21 Worldwide wonderment

MICHELLE KIENER – They say that if you around the world in a time when silent were to just glace at every piece of art movies were still state-of-the-art Michelle Kiener studied in the Louvre in Paris, that it would take technology. electronics engineering at the Merchant Navy you nine months to see everything. My College, UK and has an experience of visiting ABB Review’s That is why I have chosen to highlight MSc in environmental archives was very similar. I’ve worked the following article out of the thou- science. She has been for ABB, and read the Review, for sands that I could have chosen. For an editor for the Review for four years. [email protected] 15 years yet if I chose to read all of the me, it sums up perfectly the pioneer- articles that I wanted to it would have to ing spirit, intrepid nature and “can do” be my new full time job and it would attitude of all the many people that essential part of sharing their achieve- probably take me beyond retirement make up ABB, both now and in the ments, recording developments and age! There was so much fascinating past. And the Review has been an documenting excellence. material that it was extremely difficult to stick to the available research time.

Overall, the most striking thing for me was the global nature of both the Review and of ABB. It is normal these days to think globally, to cross an ocean in an afternoon, to talk of global reach and globalization, to send a “letter” which arrives on another continent seconds later. And yet the Review, as well as its preceding parent companies, ASEA and BBC, were global entities long before such buzzwords and high-speed travel and communications were common place.

In 2014, delivering massive hardware to customers still has its challenges, be they available and suitable transport, inclement weather or low bridges en route – all now coordinated and com- municated via e-mail and smartphones. Even sending ABB Review around the world has its challenges, be they the array of import regulations or managing the global list of subscribers’ which our team of 102 local country distributors have to stay on top of. So I can hardly begin to imagine what achieving the same end result would have been like 100 years ago. Imagine manufacturing, in 1914, a turbine in Switzerland that needs to be delivered to Australia. Imagine sending the commissioning staff there to install it and how long they would have been away from home and with no “local assistance” from Google or a lightweight dictionary in their smartphone. Imagine sending printed copies of the Review to different addresses

22 ABB review 2|14 Air heater for space research

ANDREAS MOGLESTUE – The archives of ABB still has involvement in space ABB Review represent a good cross research today – for example through Andreas Moglestue section of the company’s activities its Fourier transform infrared spectros- studied electrical engineering at ETH Zürich. throughout the last 100 years of its copy (FTIR), which is carried on He worked for ABB history. While there are domains in satellites to study the atmosphere. Semiconductors and also which BBC and ABB have been active developed software before throughout this period, there are also This brief insight into the back story of joining the Review team. [email protected] product areas that have been discontin an otherwise seemingly random item ued or sold, and others again have been of equiment is illustrative of the way introduced through internal innovation ABB’s achievements were often or through the acquisition of other contributory to a broader context. companies. Besides these, there are also articles dedicated to rare or one-off products engineered specifically for a particular application.

An article on an air heater for space research discusses an air heater that produces a hypersonic jet of air, able to heat air at 80 to 100 atmospheres to some 1,000 °C and blow it at Mach 12. This heater was produced by Tecnoma- sio Brown Boveri S.A. in Milan for the Centro Richerche Aerospaziali in Rome.

The 1968 BBC Review article discusses the engineering and testing of the heater, but only hints at the application. The Centro Ricerche Aerospaziali was at the time the aerospace research group of the University of Rome La Sapienza, and was working on a satellite launch program called San Marco. Italy launched her first satellite (San Marco 1) in 1964. This was one of the first-ever non-Soviet or US spacecraft. It was nevertheless launched from Wallops Flight Facility in Virginia, United States using a NASA Scout rocket and under NASA super vision. The satellite carried an ion probe to study the atmosphere and equipment to study the effects of long-range radio transmission.

In the following years, the Italians created their own rocket launching platform (also called San Marco) near Ras Ngomeni (Kenya) from which at least 27 rockets were launched between 1964 and 1988.

100 years of ABB Review 23 IRB 6000

IRB 2000

IRB 90

IRB 6

Rise of the robot

Celebrating 40 years DAVID MARSHALL, NICK CHAMBERS – In this centenary edition of ABB Review, one other important anniversary can be celebrated: of industrial robotics It has been 40 years since ABB (then ASEA) introduced its first robot, the ASEA IRB 6, thus launching ABB’s fascinating story in robotics. at ABB As the world’s first all-electric, microprocessor-controlled, commer cially available industrial robot, the IRB 6 was a historically significant machine. Since its launch, the field of robotics has changed drastically – almost beyond recognition. While many new and groundbreaking robotic developments have come along over the years, it is the technologies that have made robots easier to use and that have lowered the barriers to robot implementation that have made the biggest difference and accelerated the pace of robotic adoption.

24 ABB review 2|14 The advances made in robotic IRB 6700 technology over the past four IRB 6600 decades have been astounding.

ndustrial robots can now to be found The first-ever industrial robot appeared It set new standards in footprint size, in discrete manufacturing environ- in 1961 when a hydraulically driven “Uni- speed of movement and repeatability, ments across the world. They increase mate” was supplied to General Motors and gave rise to a number of imitators. I productivity, ensure consistently high for tending a die quality and improve workplace safety. casting machine. The advances made in robotic technolo- Hydraulics domi- Hydraulics dominated robotics gy over the past four decades have been nated robotics un- astounding: Where once single robots til, in 1974, the until, in 1974, ASEA developed performed relatively simple and monoto- Swedish company the IRB 6, the first all-electric, nous tasks in hazardous environments, ASEA (later to now multirobot synchronized systems deal merge with Brown microprocessor-controlled, with sophisticated assignments in flexi- Boveri to form ble production cells. ABB has played a ABB) developed the commercially available indus- major role in driving this robot revolution. IRB 6, the first all- trial robot. electric, microprocessor-controlled and commercially available industrial Spot welding soon became a prime robot ➔ 1. This 6 kg payload capacity application area and the IRB 90, machine was unique, not only in its drive launched in 1982, was designed spe- Title picture system but also in its anthropomorphic cifically for this task. This full six-axis Robotics technology has progressed dramatically in the past four decades. In particular, robots have configuration and its innovative use of device, with integrated water, air and become much simpler to implement and use. a microprocessor for accurate control. electrical feeds built into the arm, made

Rise of the robot 25 The most recent 1 First IRB 6 customer – overview of cell addition to ABB’s range of painting robots is the compact and all-new IRB 5500 FlexPainter.

major inroads into the spot welding change was the switch from direct cur- business. rent (DC) to alternating current (AC) drive motors, which are smaller, brushless Robots for painting (easier to maintain), more powerful and It did not take long for robots to move they have a longer life – all features de- into the painting arena and, in 1985, manded by industrial users. ASEA released its first electric drive painting robot, the TR 5000. Later, in the Heavy-duty robots 1990s, ABB invented the cartridge bell Flexibility and adaptability are features system (CBS) for painting car parts. The constantly called for by robot users. In system utilizes easily replaced paint car- 1991, ABB met these demands head- tridges to reduce paint and solvent on with the heavy-duty (150 kg payload waste, thereby cutting costs and reduc- capacity) IRB 6000. Aimed primarily at ing emissions, while at the same time spot welding and large component han- offering a wider choice in paint colors. dling, the IRB 6000 was built on a modular concept with a range of base, arm The most recent addition to ABB’s range and wrist modules so that it could of painting robots is the compact and all- be optimized for each user’s needs – a new IRB 5500 FlexPainter ➔ 2. The design philosophy that ABB still uses unique design and configuration of the today. With features that appealed to a wall-mounted FlexPainter has created broad range of customers, the IRB 6000 the largest and most flexible robot work- was an instantly successful spot-welding envelope of any exterior car body ing robot. The newest model in this paint robot. Two FlexPainter IRB 5500s family, the IRB 6700, follows in the can handle jobs that, until now, required IRB 6000’s footsteps as the highest- four paint robots. The results are lower performance robot in the 150 to 300 kg costs, both initially and in the long run, segment. The IRB 6700 has a 20 percent faster installation, high uptime and better lower total cost of ownership (TCO) than reliability. its immediate predecessor, the IRB 6640, thanks to a more robust design, longer Robot mechanics service intervals and simplified mainte- Such was the elegance of the IRB 6 design nance. Reliability was a key design con- that its basic anthropomorphic kinematics sideration for the IRB 6700 – it is designed with rotary joint movements can be seen for a mean time between failures (MTBF) in today’s range of ABB robots. What has of 400,000 hours. To achieve this level changed over the years is speed, accu- of reliability, each and every IRB 6640 racy and space efficiency. failure report was analyzed and the les- sons learned were used for the IRB 6700 Backlash-free gearboxes replaced ball design. With 15 percent less power screw drives for the “hip” and “shoulder” consumption, it is also easier on the envi- axes early on, resulting in better space ronment and on the utility bills. kinematics. But the other significant

26 ABB review 2|14 2 IRB 5500 3 IRB 6700 with LeanID

Well dressed The IRB 120T variant is for rapid pick The reliability of a robot’s dressing – the and place applications that require ex- Such was the cables and hoses that deliver air, elec- treme flexibility combined with industry- tricity, fluids, welding wire, etc. to the leading 10 µm repeatability. The six-axis elegance of the end of the arm – is at least as important IRB 120T delivers a substantial increase IRB 6 design that as the robot itself. In many cases, dress- in the maximum speeds of axes four, five ing wear is what causes the most service and six, resulting in cycle-time improve- its basic anthropo- headaches. Swinging cables not only ments of up to 25 percent. wear faster, but also limit the free move- morphic kinematics ment of the robot. Fully integrated dress- High-speed pick and place robots ings (IDs) – ie, those internal to the robot ABB introduced the IRB 340 FlexPicker® with rotary joint – are costly and can be limiting in terms robot in 1998 – another historically sig- movements can of what can be run through them. ABB’s nificant robot in that it was the first “delta- new LeanID achieves a balance between style” robot available for pick-and-place be seen in today’s cost and durability by integrating the applications. It was capable of an im- most exposed parts of the dress pack pressive 10 G acceleration and 150 range of ABB into the robot ➔ 3. This makes program- picks per minute, bettering human oper- robots. ming and simulation more predictable, ators by orders of magnitude in both creates a more compact footprint and, speed and versatility when handling because wear and tear is reduced, length- small items, such as electronic compo- ens service intervals. ABB’s newest nents and food products. robot, the IRB 6700, has been designed to accommodate LeanID from the start. The FlexPicker’s software offers a combination of high-performance motion Small is also beautiful control with integrated vision guidance Sometimes robots have to be small. and conveyor tracking. The current stan- ABB’s smallest-ever multipurpose indus- dard model (IRB 360) is also available trial robot, the IRB 120, weighs just with longer arms and multiple payload 25 kg and can handle a payload of 3 kg capacities from 1 to 8 kg depending on (4 kg for a vertical wrist) with a reach of needs, and a working range of up to 580 mm ➔ 4. A white-finish cleanroom 1.6 m ➔ 5. These new features enable ISO 5 (class 100) version, certified by the the machine to perform pick-and-place IPA (Fraunhofer-Institut Produktionstech- actions over longer distances than ever nik und Automatisierung), is also avail- before and also perform well even with able. heavy multiple item picks.

Rise of the robot 27 Reliability was a 4 IRB 120 at ABB SACE in Frosinone key design consideration for the IRB 6700 – it is designed for a mean time between failures of 400,000 hours.

Palletizing 12 punch buttons, and rudimentary soft- One application area for robots that has ware for axis interpolation and movement grown enormously in recent years is pal- control. The robot required specialist letization ➔ 6. ABB’s new IRB 460 is the knowledge to program and operate. Forty fastest palletizing robot in the world. years and four control system generation Compact, and with a lifting capacity of changes later the picture looks completely 110 kg, this four-axis robot is capable of different: IRC 5, ABB’s fifth-generation up to 2,190 cycles per hour and so is robot controller, is specifically designed to perfect for high-speed end-of-line pallet- make robots easier to use and lower the izing and bag palletizing. The IRB 460 barriers to integration of robots into exist- has a reach of 2.4 m, occupies 20 per- ing factories ➔ 7. cent less floor space and runs 15 percent faster than its nearest rivals. IRC5 offers superior motion control and rapid incorporation of additional hard- Modern robot offerings extend far be- ware. Its motion control technology, fea- yond the robot itself and the IRB 460, for turing TrueMove and QuickMove, is key example, comes with the PalletPack 460 to the robot’s performance in terms of Function Package. This is a set of pre- accuracy, speed, cycle time, program- engineered products configured for end- mability and synchronization with exter- of-line palletizing that greatly improves nal devices. QuickMove determines the ease of use for integrators. maximum acceleration possible in any move and uses it on at least one axis so For high-output, full-layer palletizing, that the end position is reached in the ABB has the IRB 760 robot. With a pay- shortest time. TrueMove ensures the load capacity of 450 kg and a reach of motion path followed is the same what- 3.2 m, this robot features high wrist iner- ever the speed and obviates the need for tia – double that of competitors – that “path tuning” when speed parameters enables it to rotate heavier and larger are adjusted online. Other features in- products faster than any other robot in clude ABB’s well-known FlexPendant this class. This superior speed makes interface device with a touch screen and the IRB 760 especially suited for pallet- joystick programming, the flexible RAPID izing full layers of beverages, building language, and powerful communication materials and chemicals. capabilities.

Advances in control systems Recently, ABB introduced a compact In 1974, the IRB 6 control system had just version of the IRC5 for applications a single 8-bit Intel 8008 microprocessor, where footprint has to be minimized, but an HMI with a four-digit LED readout and full IRC 5 functionality guaranteed.

28 ABB review 2|14 5 IRB 360 in action 6 IRB 660 palletizing drums of paint

RobotWare is at the heart of the system FlexFinishing and force control and features a number of optional plug- Another recent leap forward is ABB’s ABB’s new LeanID ins designed to increase functionality FlexFinishing system featuring Robot- and ease of use for robot users. For ex- Ware Machining Force Control for deli- achieves a balance ample, multitasking, transfer of informa- cate operations – specifically, for grind- between cost and tion from file to robot, communications ing, deburring and polishing castings. with external systems or advanced mo- This unique robot application, first durability by inte- tion tasks. launched in 2007, contains a programming environment that allows the robot grating the most A salient feature of IRC 5 is its MultiMove to find the optimum path itself. A feed- exposed parts of function, which allows control of up to back loop controls the speed and pres- four ABB robots plus work positioners or sure of the tool. the dress pack into other servo devices – a total of 36 axes – in a fully coordinated manner. The application allows simple and effi- the robot. cient programming by using the force Although complex, setting up and oper- sensor to define the trajectory for the ating such a multi-robot cell with fully robot movement – the operator simply coordinated motions is made easier with moves the robot by hand to teach it the the FlexPendant, the world’s first open rough path. The robot automatically fol- robot operator interface unit, developed lows the part, recording the exact path for IRC5. and generating a robot program.

Next-generation robot safety This innovative approach not only im- To ensure the safety of people working proves the quality of the finished parts, with industrial robots, humans and ro- but it also reduces overall programming bots were traditionally separated by time by up to 80 percent, reduces the fences, and expensive safety equipment cycle time of the robot by 20 percent and was necessary. ABB’s SafeMove reduc- extends the lifetime of the grinding tools es the requirement for such equipment. by 20 percent. Other function packages SafeMove is an independent computer for precision work are available – for glu- housed in the IRC5 cabinet that allows ing, for example. The gluing package the reliable, fault-tolerant monitoring of provides perfectly coordinated robot mo- robot speed and position, and the detection and adhesive dispensing with con- tion of any unwanted or suspicious devi- veyor tracking. High precision and con- ation from the norm. If a safety hazard is sistent robot-based gluing/dispensing detected, SafeMove executes an emer- not only enhances parts quality, but gency stop, halting the robot within a reduces cycle time, too ➔ 8. fraction of a second.

Rise of the robot 29 7 IRC 5 controller 8 Gluing function package

Computer-based programming configuration files identical to those used Over the years, it has become clear that on the shop floor ensures everything in the easiest, fastest, most accurate and the virtual world works exactly as it will in most flexible way to program robots is the real world. on a computer in the office before ever even touching any physical equipment in For developers, this method of program- the real world. ming is very efficient and can be done without time pressure or the constraints This is the best way to maximize return of pre-existing equipment locations. By on investment for robotic systems, re- lowering the barriers to robotic integra- sulting in lower costs, faster time to mar- tion through ease of programming, cus- ket and superior end products. tomers and integrators both see reduced costs and faster times to market, result- ABB RobotStudio allows programming ing in a virtually instant return on invest- to be done on a computer without com- ment. mitting to construction or disturbing existing production. It simplifies the pro- Ready to go cess of programming robots and makes Standardized manufacturing cells are it easier to design solutions for complex removing some of the last barriers to production environments. the implementation of robotics. Instead of building robot cells from scratch, cus- Among all computer-based robot pro- tomers can use ABB’s FlexLean con- gramming solutions, RobotStudio is cept, which offers a compact cell in unique in that it is built on the ABB Vir- which the robots, controllers and cabling are pre-mounted on a platform. Flex- Lean offers auto- The Flexpicker’s software motive manufac- offers a combination of high- turers both geo- metrical assembly performance motion control and respot cells that come with a with integrated vision guid- choice of pre- ance and conveyor tracking. defined configurations and a broad range of robotic tual Controller, an exact copy of the real products. This results in cells so cost- software that runs on ABB production efficient that they can compete with robots. Using real robot programs and manual labor in low-cost countries.

30 ABB review 2|14 9 FlexArc – the complete welding package 10 Integrated Vision

An addition to the range of standardized Integrated Vision’s extensive library of vi- The age of the industrial robot cells is ABB FlexArc® – a complete arc sion commands makes it easy to use – Since ASEA presented the first all-elec- welding package ➔ 9. It includes all the even for first-time vision users. ABB’s off tric, microprocessor-controlled robot in components necessary for robotic arc line 3-D programming tool, RobotStudio, 1974, industrial robotics has come a welding: Robots, IRC 5 with support for offers, as standard, ready-made compo- long way – and the pace of change multiple-robot coordination, positioners nents for easy programming of the robot is only accelerating. This year, ABB and welding equipment. Customers can and the vision system. expects to sell its 250,000th robot and choose between several single- or multi- is primed to continue pioneering new robot production solutions. All internal Remote service developments, and building a compre- cables are routed and connected in the Reduced robot performance can signifi- hensive range of industrial robots, robot factory. Again, all cell components are cantly impact production. This is why controllers, associated software and mounted on a common base, eliminating ABB introduced remote service technol- innovative service options. In 40 years, the need for on-site engineering work. ogies and has now built up a global ser- positioning accuracies have improved Software has been preconfigured for vice with 1,200 service specialists in from 1 mm to 10 µm, user interfaces simple setup and operation. As a pack- more than 50 countries and over 100 lo- from a 4-digit LED readout to a full Win- aged solution, a FlexArc cell can be cations. ABB’s installed base of more dows touch-screen display and memory moved within or between different pro- than 230,000 robots offers huge benefits capacity from 8 kb to many terabytes. At duction facilities. This allows engineers of scale and means that world-class ser- the same time, reliability has increased to design highly flexible plant layouts vice can be provided at a reasonable enormously and costs have plummeted that meet today’s demands for rapid cost. This aspect is one important mar- so far that, today, a robot costs less than changeovers. ket differentiator for ABB. half of what it did 10 years ago. The age of the industrial robot has arrived. Robot eye With remote service, robot data is sent Even in the last decade, vision technol- from the controller to a service center for ogy has progressed tremendously and automatic analysis and scrutiny by a ABB has recognized that a powerful subject matter expert. The expert can vision-guided robotics system can help remotely identify the cause of a failure overcome many manufacturing chal- and provide rapid support to the end lenges. user. Many issues can be solved without site visits. The automatic analysis can The ABB Integrated Vision product, not only provide a failure alert, but can David Marshall which can be used in many industries, also predict future difficulties. At any time ABB Robotics features 50 powerful vision tools, autofo- and from anywhere, a user can verify Milton Keynes, United Kingdom cus, integrated lighting and optics, faster robot status and access important main- [email protected] image capture, capability to power and tenance information about that robot control a range of external lighting and system by logging into ABB’s online Nick Chambers enough input/output capacity for virtually MyRobot portal. ABB Robotics any inspection scenario – all in a com- Auburn Hills, MI, United States pact IP67 package ➔ 10. [email protected]

Rise of the robot 31 32 ABB review 2|14 60 years of HVDC

ABB’s road from pioneer to market leader

ANDREAS MOGLESTUE – Looking back on the clash between Edison’s DC and Tesla’s AC in the “War of the Currents” of the 1880s, it is often summarily assumed that the question was settled once and for all. But during the last 60 years, DC – at higher voltages than Edison could have imagined, has been making a steady comeback. HVDC is now an indispensable part of transmission grids across the world, and is set to expand into further markets still. The history of ABB is intricately intertwined with that of HVDC: ABB’s predecessor compa nies pioneered the technology and ABB is not only firmly established as market leader today, but is the only company able to supply the complete scope of HVDC components, including the overall engineering as well as transformers, converter stations, semiconductors, cables and control systems.

Title picture The world’s first HVDC thyristor valves (foreground) connected in series with the original converter (background) at Gotland (circa 1970)

60 years of HVDC 33 1 Reactive power limits the distance over which AC transmission is viable.

5,000

800 kV

4,000

500 kV

HVDC 3,000

2,000 765 kV Transmission capacity (MW) Transmission

1,000 HVAC 500 kV

0 0 200 400 600 800 1,000 Length of transmission line (km)

son’s idea is enjoying some revindication was growing in sectors such as rail trans- at present through the concept of micro- portation, aluminum smelting and tele- generation – in which customers can communications, in all of which it is still of feed self-generated electricity (eg, solar) great significance today. New applications into the grid. added since include data processing and he transmission of electricity photovoltaics. However, in terms of trans- over large distances requires The second prong of Edison’s counter- mission and distribution, AC’s superiority high voltage levels. Because attack was to try his own hand at trans- appeared unassailable. But was it really? T ohmic losses are proportional mitting electricity at higher voltages to the square of the current, every dou- (seemingly in discord with his anti-high- Drawbacks of AC bling of the voltage reduces losses to voltage activism). In 1889, Edison built a Despite the rapid adoption of three-phase one quarter. The simplest way of achiev- 22 km line from Williamette Falls to Port- AC for transmission and distribution, lon- ing high voltage levels is to use trans- land, Oregon (United States) transmitting ger AC lines face drawbacks. The most formers. But unfortunately for the DC about 130 kW at 4 kV. The voltage level important of these is the phenomenon of faction during the War of the Currents, was obtained through the series connec- reactive power. Reactive power is the flow the principle of transformation only ap- of energy that con- plies to AC. DC’s principal proponent, tinuously charges Thomas Edison, was however not one Already during Edison’s and discharges the to give up easily. Rather than admitting line’s electric and defeat over this simple fact of physics, lifetime, DC was growing in magnetic fields to he resorted to a double-pronged coun- many sectors. accommodate the ter-attack. On the one hand he drew periodic oscillation attention to the safety hazards of higher of the line’s voltage voltages, sometimes resorting to horrific tion of generators (a principle that was and current. Although not directly waste- methods to instill public distrust of them first demonstrated at an exhibition in ful (the energy is recovered as the fields (he once had an elephant electrocuted Munich, Germany, in 1882). Symptom- discharge), the additional current and and also played a part in the creation of atically with the demise of DC, the voltage on the line subtract from its useful the first electric chair). As an alternative Oregon line was to be short-lived: It was economic capability. As capacitance and to high-voltage transmission, Edison heavily damaged by a flood in 1890 and inductance increase with the length of the promoted local generation. This meant then rebuilt as an AC installation by line, reactive power also grows until a providing a power plant in every neigh- Edison’s competitor, Westinghouse. point is reached that commercial trans- borhood (the limit for the commercial mission ceases to be viable. It is ironic transmission of 110 V DC being about But the history of DC transmission did not that the laws of physics that enable trans- 1.6 km). Although the urban pollution end with that flood. As late as 2006 there formation and make high-voltage AC from such plants would have been prob- were still 60 customers connected to the transmission possible in the first place are lematic (especially considering the gen- Edison DC supply in New York City (the the same laws that ultimately limit the dis- eration technology of the day), and the supply was finally switched off the follow- tance over which it is useful ➔ 1. very suggestion may sound risible ing year). But much more significantly, through the perspective of history, Edi- already during the inventor’s lifetime, DC

34 ABB review 2|14 2 Mercury-arc valve 3 Uno Lamm, the “father of HVDC,” in the control room of the Gotland HVDC

Steel anode

Mercury vapor Arc

Mercury cathode

There are solutions to the reactive power and the mercury, the bombardment by challenge – for example FACTS devices ions causes electrons to be released. As capacitance that compensate reactive power. How- The steel can absorb electrons but does ever, DC transmission eliminates the not release significant quantities at the and inductance problem entirely as the line’s electric and operating temperature. Current can thus magnetic fields are constant and thus flow from the steel to the mercury but not increase with the only need to charged when the line is in the reverse direction. The mercury length of an AC powered up. valve thus displays diode functionality, making it suitable for AC to DC conver- line, reactive power Mercury-arc valves sion. Early attempts at DC transmission at also grows until a higher voltages relied on the series con- But mercury valves can also perform the point is reached nection of generators or motor-genera- reverse (DC to AC) conversion: An artifi- tors.1 The principle was thus limited by cial triggering of the arc (using an induc- that commercial mechanical constraints and was unable tor to apply a voltage peak to an auxiliary to economically compete with AC. electrode) permits conduction to com- transmission ceas- mence at an arbitrary point in the cycle. es to be viable. Interest in DC conversion resurged when a new technology came onto the scene: By being able to perform both conver- the mercury-arc valve.2 This valve is a sions, mercury valves permitted the use sealed bulb filled with mercury vapor us- of transformers, thus combining the ing steel anodes and a mercury cath- transformation advantages of AC with ode ➔ 2. Once an arc is initiated between the transmission advantages of DC. anode and cathode, the current flowing in the arc generates heat and ionizes the The mercury arc valve was first demon- mercury vapor. At the interface of the arc strated in 1902 by the American inventor Peter Cooper Hewitt. ABB’s predecessor company, BBC (Brown, Boveri & Cie), Footnotes was a leader in their development, with 1 A motor generator is a motor and generator pair sharing the same shaft. An array of motor-gener- commercialization beginning in 1913. ators can be used to increase DC voltages by Early installations, however, did not target connecting the motors in parallel but the DC transmission but were used to rectify generators in series. lower voltages (up to about 2,500 V) for 2 Mercury arc valves and ABB’s part in their 3 development are discussed in greater length in industrial and transportation purposes. “From mercury arc to hybrid breaker” in ABB Review 2/2013, pages 70–78. One of the problems encountered as volt- 3 Nevertheless, BBC did demonstrate a temporary ages were increased was that of arc- DC transmission in 1939. It transmitted 500 kW at 50 kV over 25 km between Wettingen and back. An arc-back occurs when a reverse Zurich in Switzerland. voltage across an unignited valve sparks

60 years of HVDC 35 4 Schematic of the Gotland link, showing the series connection of converters in 5 The three valves of one converter of the both stations Gotland link (with Lamm’s wife, Pamela)

The synchronous condenser (28) was to control reactive power and assure local commutation on the Gotland side (the link replaced a local power plant; there was thus no local commutation).

ASEA Journal, 1954, p. 142

an involuntary arc in the reverse direction. struction commenced in 1943, with oper- The Gotland link- This not only causes a malfunction of the ation beginning in 1945. A 50 km, 6.5 MW, circuit but can cause permanent damage 90 kV line was built to Mellerud, where provided many to the valve. It was another of ABB’s pre- another converter station was added. decessor companies, ASEA (Allmänna This transmission line was built purely for new challenges for Svenska Elektriska Aktiebolaget) that was test purposes, a role it continued to fulfill ASEA, not least of to provide the next breakthrough. In 1929, until its decommissioning the late 1960s. Uno Lamm ➔ 3 was awarded a patent for which was the sea controlling arc-back by using grading Gotland electrodes. Grading electrodes are inter- In 1950 Swedish parliament approved an crossing. mediate electrodes connected to a volt- HVDC link between the island of Gotland age divider to prevent an arc from being and the Swedish mainland ➔ 4 – 5. This able to form from anode to cathode in a link provided many new challenges for single strike. For this work and its conse- ASEA, not least of which was the sea quences, Lamm is often called “the father crossing. For this purpose, an under of HVDC.” water cable was developed.

Despite this patent, the road from the On March 7, 1954, the 200 A link was pow- basic idea to a reliable implementation ered up, initially at 50 kV. This was doubled was long. Due to the often unpredictable to 100 kV on July 26, when the second pair behavior of arcs, valve development of converters were added in series. The era was very much a process of empirical of commercial HVDC had begun. research. In order not to destabilize the electrical grid in the town of Ludvika The ASEA Journal marked the event with an (where the development lab was located) article penned by Lamm himself ➔ 6. He high-power trials had, at times, to be opens with the words: restricted to nightly hours. “The realization of the high voltage D.C. The Swedish State Power Board (SSPB, transmission from the Swedish mainland now Vattenfall) followed ASEA’s progress to Gotland is a high point in a very exten- with interest. By the early 1940s, the sive development work in Sweden, the technology was sufficiently mature for a beginnings of which can be traced back trial converter station to be built. Trollhät- a long time”. tan was chosen as the location for this (due to the adjoining power plant). Con-

36 ABB review 2|14 6 First page of Lamm’s article from the ASEA Journal of 1954, presenting the Gotland link ASEA’s labs commenced thyristor development in the mid-1960s.

“The converter valves, as the most criti- company worldwide that is able to pro- cal part of a D.C. plant, have always vide from a single hand all parts of an formed the focus of this development HVDC system, ranging from transform- work. The total scheme has, however, ers, converter stations and their compo- covered many other spheres such as nents, to the cables, control systems converter technique generally, the prob- and more recently, breakers. lems of earth return, cable construction and laying, interference with telecommu- ASEA’s second commercial HVDC proj- nication circuits, corona phenomena on ect was a 160 MW link between Britain overhead lines, the behavior of suspen- and France, inaugurated in 1961. Further sion insulators with direct voltage, etc.” projects, ranging from Scandinavia to Italy, Japan, Canada and New Zealand, The latter paragraph would not look out followed in the 1960s, several of them of place in any publication on HVDC of again involving sea crossings using cables. the past 60 years: The basic principles The culmination of the development of established for Gotland still hold today, mercury-arc based HVDC was the Pacific with ASEA (and later ABB) having built Intertie, a 1,300 km, 1,440 MW (raised to up expertise in all of the areas men- 1,600 MW in 1982), 500 kV link between tioned. In fact ABB is today the only Celio (Oregon) and Sylmar (southern

60 years of HVDC 37 7 A selection from numerous HVDC projects delivered by ABB. The company has supplied As an alternative more than half the world‘s 170 projects.

Year Project Converters Distance Power Voltage to high-voltage (km) (MW) (kV)

transmission, 1946 Trollhättan - Mellerud (test line) 50 6,5 45

Edison promoted 1954 Gotland 1 98 20 100 Mercury-arc valves local generation. 1961 English Channel 64 160 100 1970 Pacific Intertie 1300 1,440 500

1979 Cahora Bassa 1420 1,920 533

1983 Gotland 2 99 130 150

1987 Itaipu 780 6,300 600

2004 Three Gorges – Guangdong 940 3,000 500 Silicon 2007 Three Gorges to Shanghai 1060 3,000 500

2008 NorNed 580 700 450

2010 Xiangjiaba – Shanghai 1980 6,400 800

2013 Rio Madeira 2375 7,100 600

2,500

2,000

1,500

1,000 Distance (km)

500

0 1940 1950 1960 1970 1980 1990 2000 2010 2020

Year

8,000

6,000

4,000 Power (MW)

2,000

0 1940 1950 1960 1970 1980 1990 2000 2010 2020

Year

800

600

400 Voltage (kv) Voltage

200

0 1940 1950 1960 1970 1980 1990 2000 2010 2020

Year

38 ABB review 2|14 8 An early ASEA thyristor-based converter HVDC Light uses voltage source converters (VSCs) with IGBTs, a technology derived from that used in industrial drives.

California), built jointly with General Elec- ASEA commenced thyristor develop- tric (GE) and inaugurated in 1970. ment in the mid 1960s. In 1967 a test converter station was fitted to the Got- Until ceasing development of mercury- land link. In 1970, thyristor converters arc valves in 1971, ASEA had used were added in series to the existing mer- them in links with a total power of cury-arc stations ➔ title picture, raising the 3,400 MW ➔ 7. operating voltage to 150 kV (while retain- ing the original cable, which had no trou- Thryristors ble coping with the increased voltage.) 4 Commencing in the 1960s, a new type of valve came onto the scene, ultimately to HVDC projects delivered during the 1970s displace mercury-arc technology ➔ 8. include the Skagerak link between Norway and Denmark, Inga-Shaba in the Congo, The principle of the thyristor was first pro- the CU project in North Dakota, United posed by William Shockley in 1950. A thy- States, and Nelson River 2 in Canada. ristor is a semiconductor device with three terminals (anode, cathode and gate). As in During the mercury-arc era, ASEA had a semiconductor diode, current conducts been practically alone in the market for in one direction only, with a reverse voltage HVDC, but the disruptive innovation caused depleting charge carriers from the junction by the greater simplicity of working with thy- area. The thyristor has additional layers ristors enabled many new competitors to between the p- and n-zones that normally enter the field. BBC, for example, teamed also prevent conduction, but the applica- up with Siemens and AEG to supply the tion of a trigger current to the gate floods Cahora Bassa link between Mozambique this area with charge carriers and permits and South Africa in the mid-1970s. ASEA conduction. Once conduction is initiated, responded to the new competition by in- the production of charge carriers becomes vesting in research to establish its leader- self-sustaining and the gate current can be ship in HVDC thyristors. removed. Conduction does not cease until the main current falls below a threshold A landmark project of the 1980s was the value. The overall functionality is thus 6,300 MW Itaipu link in Brazil, awarded to a broadly comparable to that of a triggerable consortium of ASEA and PROMON, which mercury-arc valve, but with the advantage was put into service in stages between of being much more compact, having lower losses and eliminating the risks that Footnote come with handling mercury as well as 4 The Gotland 1 link remained in use until 1986. Today the island is connected by two HVDC being well suited to the series connection links, Gotland 2 and 3, commissioned in 1983 of multiple devices to create valves for and 1987, respectively, with a total capacity of higher voltages. 260 MW.

60 years of HVDC 39 As early as 1992, 9 The Jingzhou station of the Three Gorges Guangdong HVDC link ABB proposed a grid of HVDC lines as an overlay over the existing power grid, relieving it of long-distance bulk flows.

1984 and 1987. The 2,000 MW Québec – the higher capacitance of sheathed cables New England project delivered around the versus lines) ➔ 10. For example, in 2008, same time link was the world’s first multiter- the NorNed link bridged the 580 km be- minal HVDC link. tween Norway and the Netherlands.

In 1988, ASEA and BBC merged to form Going light ABB. In 1995, the company launched a On a smaller scale, HVDC can also be new generation converter station. A key used to connect offshore windparks or feature was the use of capacitor commu- supply power to oil and gas platforms ➔ 11. tated converters (CCCs), permitting valves For the lower power classes, ABB intro- to be switched off rather than having to duced HVDC Light® in the 1990s. Rather wait for a current zero crossing. This was than using thyristor valves, HVDC Light the most fundamental change in switching uses voltage source converters (VSCs) since 1954, and permitted an improve- with IGBTs, a technology derived from that ment in controllability and reduction in re- used in industrial drives. The higher con- active power. The first project to use this trollability, reactive power control capability technology was the 2,200 MW Brazil – Ar- and black start capability of HVDC Light gentina (Garabi) interconnection of 1999. means it can be connected to island networks with no local commutation, but can ABB continued to raise voltage and power also be used to relieve pressure on or sta- levels. In 2004, the Three Gorges – Guang- bilize existing AC grids. The compact de- dong HVDC link (China) was opened, sign of HVDC Light means converter sta- transmitting 3,000 MW over 940 km at tions can be fitted inside containers and ± 500 kV ➔ 9. In 2007, a 1,060 km link of delivered to site in one piece, simplifying the same ratings connected Three Gorges testing and commissioning. to Shanghai. 2010 saw the Xiangjiaba – Shanghai ± 800 kV, 6,400 MW, 1,980 km The HVDC grid UHVDC (ultrahigh-voltage DC) link go into Many new challenges face tomorrow’s service. In 2013, the Rio Madeira link in power grids. Not the least among these is Brazil began transmitting 7,100 MW over the radical transformation of the genera- 2,375 km. tion landscape. Traditional power plants were mostly built close to the centers of But HVDC is not just about ever larger consumption, but the rapidly increasing power ratings spanning ever growing dis- market share of renewables means that tances. Continuing in the tradition of the more and more power is coming from Gotland link, HVDC is also highly suitable remoter regions. This power must be trans for underwater connections, where it al- mitted over long distances, often through ready displays advantages over HVAC on areas where the traditional grid is weak distances measured in tens of km (due to and not suited to handle the extra load. As

40 ABB review 2|14 10 Cable of the Fenno Scan HVDC link 11 Lifting an HVDC Light offshore module into position on a North Sea oil platform. being loaded onto a ship. This link was completed in 1989.

early as 1992, ABB’s Gunnar Asplund proposed a grid of HVDC lines as an overlay over the existing power grid, relieving it of long distance bulk flows.

But building a DC grid is not as simple as it may sound. The main technical obstacle was the lack of a suitable breaker. In AC networks, breakers are used to quickly and safely isolate any section of line, for example in the case of a disturbance, without impacting the rest of the grid. When an AC breaker opens, an arc continues to conduct current between the contacts until the next zero crossing of the current. Andreas Moglestue With DC not having such useful zero cross- ABB Review ings, a different approach is required, and Zurich, Switzerland this has long prevented the development [email protected] of more complex HVDC network topolo- gies. ABB finally solved this conundrum in 2012. The hybrid breaker uses a combi- Further reading nation of semiconductors and mechanical U. Lamm, The First High Voltage D.C. Transmission with Static Convertors: Some Notes on the switches to break the DC flow in a safe Development, ASEA Journal 1954, pages 139–140. and timely manner.5 I. Lidén, E. Uhlmann, S. Svidén, The Gotland D.C. Link: The Layout of the Plant, ASEA Journal 1954, DC or AC? pages 141–154.

So, who really did win the War of the Cur- R. Wetzel, Die Geschichte des Quecksilberdampf rents? DC is advancing into areas that gleichrichters bei BBC Deutschland 1913–1963, would traditionally have been AC applica- PhD thesis University of Stuttgart, 2001. tions, but it can never fully replace AC. G. Asplund, L. Carlsson, O. Tollerz, 50 years HVDC Maybe, more than 120 years on, we can – from pioneer to world leader, Parts 1 and 2, ABB Review 4/2003, pages 6–13. call it a draw: The history books of the future will give credit to both Tesla and L. Haglöf, P. Danfors, HVDC Veterans Presentation, Visby Gotland, 2004. Edison. H. R. Zeller, The winning chips: History of power semiconductors at ABB, ABB Review 3/2008, Footnote pages 72–78. 5 See also “Breakthrough!: ABB’s hybrid HVDC breaker, an innovation breakthrough enabling G. Asplund, L. Carlsson, HVDC: ABB – from reliable HVDC grids” in ABB Review 2/2013 pioneer to world leader, ABB Review 4/2008, pp. 6–13. pages 59–64.

60 years of HVDC 41 Pumping efficiency A 100 MW converter for the Grimsel 2 pumped storage plant

HANS SCHLUNEGGER – Hydropower is one of the oldest forms of power generation and also one of the most flexible. Because water can be retained in a reservoir and released when needed, it is ideally suited for meeting demand fluctuations. When the mode is combined with pumped storage (meaning surplus electricity is stored by pumping water into the reservoir), its storage functionality can be expanded and it can furthermore be used in grid control by absorbing or generat ing the energy required to stabilize the grid. To operate more efficiently in pump ing mode, the Grimsel 2 plant of Kraftwerke Oberhasli (KWO) – in the Bernese Oberland region of the Swiss Alps – has taken into service a 100 MW converter supplied by ABB.

Title picture Kraftwerke Oberhasli is a complex of nine power plants located in the Bernese Oberland region of the Swiss Alps. The plants have a total generating capacity of 1,125 MW and an annual production of 2,200 GWh. The lakes have a combined inflow of 700 million m3/year and a storage capacity of 200 million m3.

42 ABB review 2|14 Pumping efficiency 43 more accurately balance supply and At 100 MVA, the Grimsel 2 demand. To do this efficiently, the power needs to be regulated with high preci- installation is the most power- sion. ful drive converter with DC Grimsel 2 link voltage delivered to date. KWO’s Grimsel 2 pumped storage plant in Switzerland ➔ 1 – 2 has four synchronous generators ➔ 3. Until recently, the plant’s ability to regulate power depend- ed on the starting up and shutting down of these individual units. When intermediate levels of power absorption were required, the difference could only be made up by running an additional unit in generator mode. Pumping and generating at the same time is not only an inefficient use of energy, but also wastes the plant’s most valuable resource: its water.

To regulate the plant’s power uptake more efficiently, KWO decided to equip one of the Grimsel 2 generators with a power-electronic drive. ABB won the order for this in 2010, with the installation being commissioned in 2013. umped storage is used in what is called peak shaving: Energy The converter is absorbed by pumping at At 100 MVA, the installation is the most P times of low demand (typically powerful drive converter with DC link at night) and the stored energy is con- voltage delivered to date ➔ 4. It is made verted back to electricity at times of peak of two units of 50 MW, each with its own demand. By mitigating the extreme input and output transformers ➔ 5, and is peaks and troughs of the demand curve, series-connected on both the generator pumped storage decreases reliance on and grid sides. Each of these converters other (often polluting) power sources in turn uses pairs of parallel-connected required to cover peaks. double-phase modules using IGCTs (in-

As well as bridging this classical day to Pumping and generating at night gap, pumped storage can also the same time is not only an help integrate renewables: With inefficient use of energy, but more and more so- also wastes the plant’s most lar and wind power being fed into the valuable resource: its water. grid, pumped storage can compensate for their unpredictability and vari- tegrated gate-commutated thyristors). ability, permitting consumers to continue The overall installation thus features 24 using energy from renewable sources double-phase modules. even when neither the sun is shining nor the wind blowing. The unit’s power is continuously variable between 60 and 100 MW (the lower limit Moreover, moving beyond their strict is defined by risk of cavitation in the mass-storage role, pumped storage pump runner). plants also contribute towards grid control by producing or absorbing the relatively small amounts of power needed to

44 ABB review 2|14 1 Grimsel 2 pumping-storage plant 2 Grimsel 2: the lakes at a glance

Power in turbine operation 4 × 80 MW Height above Volume when Surface area Greatest Name sea level when Power in pump operation 4 × 90 MW full (106 m3) (km2) depth (m) full (m) Average height difference 400 m

Water flow 4 × 22 m3/s Upper reservoir Lake Oberaar 2,303 58 1.47 90

Synchronous speed 750 rpm Lower reservoir Lake Grimsel 1,908 101 2.63 100 Years of construction 1973-80

3 The Grimsel 2 plant has four synchronous generators. 4 The 100 MW converter

Starting system, which adjusts the output of all In turbine operation and in unregulated KWO power plants to comply with the By the end of pumping mode, the machine set is start- loading schedule. The line-side regula- ed up with the turbine ➔ 6. The block tion setpoint is added to the loading March 2014, the transformer is magnetized by the gener- schedule setpoint. The converter power ator and connected to the 220 kV level and speed control are configured in cas- converter had after reaching synchronization condi- cade, the active power being limited by provided 3,500 tions. In regulated pumping mode, the the current pumping head and the maxi- block transformer and the two line-side mum converter power capacity. hours of controlled converter transformers would have to be switched in directly, thereby causing very Reactive power is regulated by a voltage pumping and 850 high inrush current peaks. To avoid this, control loop, set either manually or by hours of phase- the frequency converter DC link is ener- the higher-ranking 220 kV line voltage gized by the start-up transformer through control system. Active power takes pref- synchronous con- the converter diodes on the motor side. erence over reactive power. The transformers are then magnetized by denser operation. the line-side converter and afterwards Operating modes synchronized. The entire starting proce- The following modes can be operated: dure takes only about 10 s, after which – Turbine the machine is accelerated by the con- – Pumping without converter verter to 600 rpm with the watered pump (constant rpm) operating against the closed spherical – Pumping with converter (variable rpm) valve ➔ 6d. After opening the spherical – Phase-angle correction using valve, the speed is adjusted to approxi- converter mately 690 rpm according to the mini- mum power required by the current Turbine operation with converter was not operating head. considered, because adjusting the Fran- cis turbine speed to the relatively small Power control head range would not compensate the The active power is either set manually converter losses. or by the higher-ranking plant control

Pumping efficiency 45 New pumped 5 Schematic of the converter Breaker Block transformer Bypass switch

storage plants with M

13.5 kV 50 Hz direct operation (750 rpm) pump turbines are 220 kV Grid-side Double- DC link Double- Machine-side transformers phase limitation phase transformers almost exclusively 2 × 50 MVA modules modules 2 × 50 MVA equipped for variable-speed 50 Hz operation, using 46 – 51 Hz converter double-fed operation (690 asynchronous – 765 rpm) motors according 50 Hz to the state of Charging transformer technology. Converter

6 The turbine and its connections 7 The machine-room cavern, with location of the transformers and converter.

a b Transformers

c c

c c e d h e d g f

a Pressure shaft to/ d Spherical valve 333 Turbine from Lake Oberaar e Throttle operation b Pressure shaft to/ f Turbine 777 Pumping Cooling units Converter from Lake Grimsel g Pump operation c Connection pipes h Generator / motor

Project execution the existing plant cooling water network The converter delivery and erection is also installed. schedule was adjusted to the refurbish- ing work taking place at the same time. Operating experience This covered: overhaul of the hydraulic The installation has been in service since machinery, spherical valve and butterfly May 2013. By the end of March 2014 it valve, renewal of the instrumentation had provided 3,500 hours of controlled and control systems, replacement of the pumping and 850 hours of phase-syn- turbine governor and excitation equip- chronous condenser operation ➔ 9. ment, and replacement of the 220 kV switchgear. Looking ahead New pumped storage plants with pump Sufficient space was available in the turbines are almost exclusively equipped existing cavern for the entire converter for variable-speed operation, using dou- system ➔ 7 – 8. The four transformers were ble-fed asynchronous motors according installed at machine room floor elevation to the state of technology. There are seri- and the converter units in the basement, ous drawbacks to this type of motor, where the cooling system connected to however: The complex rotor is subject to

46 ABB review 2|14 8 The 100 MW converter could be accommodated in the basement of the machine-room cavern. Despite progress with other storage technologies, pumped storage remains the only mature and affordable means of energy storage suitable for grid regulation.

9 The converter permits accurate regulation of the plant’s power.

500

400

300

200

100

0 Power (MW) -100

-200

-300 22:00 00:00 02:00 04:00 06:00 08:00 10:00 12:00 14:00 16:00 18:00 20:00 22:00 00:00 02:00 04:00 06:00 08:00

19.10.13 20.10.13 21.10.13 Time

Schedule Power KWO Regulation

Schedule + tertiary Power Grimsel 2

Hans Schlunegger design limits that restrict speed increase the only mature and affordable means Kraftwerke Oberhasli AG to comply with the optimal speed of the of energy storage suitable for grid regu- Innertkirchen, Switzerland pump-turbine. Furthermore, the starting lation, and thus has an important role [email protected] procedure is much more complicated, to play in the generation landscape of sometimes even requiring pump-turbine tomorrow. The new converter at Lake For ABB-related inquiries, please contact Fritz dewatering, and compliance with Grid Grimsel is a contribution to the Swiss Wittwer ([email protected]) or Steve Aubert ([email protected]). Code requirements is more difficult. For Energy Strategy for 2050, which seeks these reasons the trend in future will be to assure the continuity of the Swiss Further reading more toward synchronous machines with energy supply while increasing the use G. Sydnor, R. Bhatia, H. Krattiger, J. Mylius, full-size converters. Fitting an existing of renewables. D. Schafer,” Fifteen Years of Operation at NASA’s pumped storage plant with a full-size National Transonic Facility with the World’s largest converter therefore offers an ideal way This article is adapted from “100 MW-Vollumrichter adjustable Speed Drive,“ NASA archive. of testing this future-oriented technology im Pumpspeicherwerk Grimsel 2” published in elec- J. Hell, M. Egretzberger, R. Schürhuber, A. Lechner, trosuisse Bulletin 3/2014. in actual practice. Experience so far with Y. Vaillant, “Full size converter solutions for pumped storage plants, A promising new technology“, the full-size converter at Grimsel 2 Hydro2012, Bilbao, Spain, 2012. pumped storage plant is very promising. H. Schlunegger, A. Thöni, “100 MW Full-Size Despite progress with other storage Converter in the Grimsel 2 Pumped Storage Plant,“ technologies, pumped storage remains Hydro 2013.

Pumping efficiency 47 Unit of power

Cutting-edge motor THOMAS EK, KARITA FORSS, TIMO HOLOPAINEN, JANNE IKONEN, OLLI LAHTINEN – ABB has introduced a new generation of motors based on design redefines power the successful, high performance rib cooled motor range, type HXR. These new motors are named “High voltage rib cooled motors, NXR” density and they achieve new levels of power density. The new motors feature improved internal and external cooling, cutting-edge coil manufactur ing methods, a state-of-the-art frame design and unprecedented levels of adaptability and serviceability. The design offers a better solution for the wide range of applications in which totally enclosed fan-cooled motors are customarily used. The improvement in power density means that it will often be possible to use a motor with a smaller frame size to achieve the same output as previous, larger designs. Initially, the motors will be available in 355 and 400 frame sizes.

48 ABB review 2|14 These motors are designed to become the new benchmark for the industry, while still complementing the existing range.

ll rotating electrical machines There has always been a demand from benchmark for the industry, while still generate heat as a result of industry for motors to become more complementing the existing range. Not the electrical and mechanical compact and, at the same time, deliver only do they produce more power per A losses inside the motor. Loss- more power. This es are particularly high during starting throws down the and they also increase with increased challenge to pro- Perhaps the main innovation loading. Cooling is, therefore, necessary duce a motor de- to continuously transfer the heat to a sign that is me- that contributes to improved cooling medium, such as the surround- chanically smaller ing air. So important is cooling to motors and more powerful efficiency is the motor’s cool- that different cooling methods for rotat- but that stays cool. ing system. ing machines are officially defined in an This is not all: the IEC standard. motor should also operate within mechanical vibration con- kilogram than previous designs, but they straints, be service-friendly and be also have longer service intervals and flexible so as to simplify commissioning. more flexibility.

The new ABB motors described here are Patent cooling Title picture the result of a long period of research The innovation that contributes most to Optimized design of cooling, coils and casting and development in which various pa- improved efficiency is the motor’s cool- allows more motor power to be packed into a smaller volume than before. And service and rameters have been optimized to ensure ing system. commissioning become easier too. that the motors will become the new

Unit of power 49 The coil has also 1 Internal cooling as imaged by a thermographic camera been improved with better use of its active materials and re-dimensioning – making the coil more compact and thus increasing its power output.

It is difficult to predict thermal efficiency, The motor’s end shields are designed to so the development team analyzed exist- be both rigid and light, with an inner suring motors, constructed computational face that facilitates internal cooling circu- fluid dynamics (CFD) models, called in lation. In addition, the interplay of the external partners to carry out simulations cooling channels and the external cool- and developed analytical calculation ing areas have been optimized – for example, the air channels do not ABB has applied for a patent interfere with the rib cooling. While for the internal cooling sys- most motors have four air channels, tem, which increases air cir- the new motor has culation through the motor only three. and routes air through chan- Upgraded nels in the stator and rotor, cooling ribs assisted by a fan. One way in which external cooling has been improved methods that could be used to finalize is with the increased number of cooling the design. Further, the CFD models had ribs. The ribs have also been lengthened to be both challenged with real measure- and their pitch and angle optimized, with ments and interpreted correctly in order all obstructions reduced ➔ 2. For exam- to turn the models and calculations into ple, the bolts and screws that hold the functioning motors. In this step, the ex- end shields in place are designed to not pertise and experience of the ABB team obstruct the air flow; a cable tray en- and its partners played a crucial role. sures that auxiliary cables are well stowed; the ribs are made so as to be ABB has applied for a patent for the in- easily cleaned; and the fixing points are ternal cooling system, which increases positioned so that accessories are air circulation through the motor and mounted on the side of the motor and do routes air through channels in the stator not affect the air flow. In addition to pre- and rotor, assisted by a fan ➔ 1. An inter- venting obstacles to air flow, the outside nal fan has been a feature of other ABB ring of the end shield is finished with a motors, but has never been so thorough- 30 degree chamfer to direct the air more ly exploited before. effectively.

50 ABB review 2|14 2 Front view of the optimized rib construction The ribs have been increased in number, lengthened and had their pitch and angle optimized, with all obstructions reduced.

The research carried out to optimize the Increased rigidity reduces vibration. One cooling process is also of benefit when it way to increase rigidity is to increase the comes to the modeling required to cus- axial and transverse dimensions of the tomize individual motors: Full-scale CFD mounting holes. More important for the modeling can take hours or even days rigidity, however, was the optimization of but parameters from the CFD modeling the mechanical design. and measurements can be extracted to allow the rapid calculation of tempera- The objective of this optimization was to ture change for a particular motor de- reduce the use of material while still sign. More accurate temperature predic- complying with the vibration require- tions mean that motors can be tailored ments of the main industrial standards. precisely to their requirements, thus en- In the past, rigidity would have been suring better performance. achieved by simply adding more metal. This solution is no longer acceptable – Lowering vibration strength and rigidity have to be achieved The new, more powerful motors are lon- by the intelligent shaping of the material ger than their predecessors and this has and not by extra mass. But the design of necessitated further work to ensure that the various elements of a motor is not an their greater length does not result in exact science. For example, the panel more vibration. Here, too, designs were between the feet serves two purposes: It developed using computers, but the vir- houses one of the three air channels and tual prototyping – in this case the finite also provides rigidity to help transfer the element method (FEM) – was unable to horizontal forces from the stator to the satisfactorily predict the characteristics feet. Calculating the best size for the air of the new design. So, components such openings at either end on the inside of as the rotor, the stator and the end the air channel or the optimum thickness shields were modeled and manufac- of the cast iron is not straightforward, es- tured. The manufactured components pecially if the amount of material and the were then measured and the FEM mod- weight of the motor are meant to be re- els were validated against the measured duced. The development teams worked data of each component. In an iterative with suppliers to achieve a casting pro- process, these two were validated cess that met design requirements and against each other until the most effec- optimized the use of material. tive designs could be identified. The final design avoided all the significant reso- One of the aspects that was considered nances that may be caused by mechani- in the modeling of this new motor was cal and electrical excitations ➔ 3. how it would function on different foundations – since problems with vibration

Unit of power 51 The research car- 3 Modelling of rotating electromagnetic traction to predict mechanical vibrations ried out to optimize the cooling process is also of benefit when it comes to the modeling required to cus- tomize individual motors.

are often caused by the interaction between the motor and the foundation on Improved cooling which it stands. It makes a considerable difference whether a motor is mounted ensures that the on a concrete block or on a steel skid. The new motor can be used with a wide motors will last lon- variety of foundations. ger and require New coil manufacturing servicing less fre- The coil has also been improved, with re- dimensioning and better use made of its quently because active materials. Making the coil more lower temperatures compact increases its power output. New tools have been developed that allow bet- in the bearings will ter control of coil-end shaping in the manufacturing process, which has improved mean less frequent quality and repeatability so that every coil lubrication. is now closer to perfection than was previously possible. Thus, a change of factory layout does The new coil manufacturing process is al- not mean that a new motor needs to be ready having an influence on production bought merely because the power comes methods in other ABB motor ranges. in from the side opposite the cable connection. And, especially in industries Flexibility of deployment where motors are used on either side of One of the most immediately noticeable a production line (metal or paper indus- innovations is the option of fitting the main tries, for example), one spare instead terminal box on either side or on either of two can be enough to meet back- end of the motor. In the case of the 400 up needs. There is no need to send frame size, it can also be fitted in the mid- the motor in for modifications – ABB dle. Changing the position of the box sim- service personnel can do all the work ply involves exchanging it for the hatch on-site. that covers the desired position ➔ 4. A wide range of options is built into the The mounting of the auxiliary terminal box basic design and this type of flexibility is also extremely flexible – it can be fitted helps to improve lead times. For in- on either side of the motor and in several stance, the end shields are pre-engi- locations along its length. neered to accommodate accessories like

52 ABB review 2|14 4 Flexible deployment The final design avoided all the significant reso- nances that may be caused by mechanical and electrical excitations.

the waste grease box and instrumenta- These new motors embody more than tion, allowing faster and easier custom- 100 years of ABB’s experience in the ization. field combined with the latest design and manufacturing technology. Also, the de- Serviceability velopments described benefit more than Improved cooling ensures that the mo- just this range of motors: Already the tors will last longer and require servicing new coil is being used elsewhere in ABB less frequently because lower tempera- – and the new cooling developments will tures in the bearings will mean less fre- almost certainly have an influence on quent lubrication. other cooling designs. The calculation tools, which are derived from virtual pro- To ensure that any problems are dealt totyping and confirmed by validation with early, the new motor can also be measurements on actual prototypes, equipped with ABB’s condition monitor- look set to be adopted within ABB. ing system, ABB MACHsense-P, or its remote monitoring system, ABB MACH- The new range of motors, which current- sense-R. The motor includes provisions ly targets 355 and 400 frame sizes, will for the installation of sensors and, for soon be extended to include other frame ABB MACHsense-R, fixing points for a sizes and additional features. monitor.

Additionally, it is now possible to exam- ine the coil ends without removing the bearing shields. The bearings them- Thomas Ek selves can be examined with an endo- ABB Motors and Generators scope and without removing the bearing Västerås, Sweden shields. [email protected]

All this helps to increase reliability and Karita Forss decrease costs. Timo Holopainen Janne Ikonen More power and know-how per kilo Olli Lahtinen The innovations in the new motor (type ABB Motors and Generators designation NXR) mean that it can often Helsinki, Finland provide the same output power as a mo- [email protected] tor one, or even two, frame sizes larger. [email protected] In extreme cases, this can result in a [email protected] weight reduction of 40 percent. [email protected]

Unit of power 53 Multitalented

ACS800 power REIJO KOMSI – Industrial drives turn, literally, the wheels of commerce. That makes drives and the technology that controls electronics can do them very important products in the industrial setting. Where several drives form part of a single process, as in a paper more than rotate machine, say, and the individual drive motors have to be a motor coupled in some way, it makes sense to use one so-called multidrive to manage all of them. ABB’s ACS800 multidrive is one such device. The ACS800 contains sophisticated software and power electronics that handle the power flow to the drive. However, with appropriate application software, the power electronics module is capable of far more than just rotating a motor. For instance, it can perform valuable power quality correction and enable the power electronics to support intentional islanding.

54 ABB review 2|14 1 A standard ACS800 multidrive schemathic. Island converters, a braking chopper, a DC/DC chopper and energy storage can also be configured.

Active power Q compensation, harmonic filtering

Point of voltage and current measurement and correction

5th 7th 1st

PQ converter/ rectifier AC DC AC

AC AC

Island Frequency converters Braking DC/DC converter chopper chopper Island converters

he multidrive approach has an active rectifier is much lower than that surement. The analysis, reference gener- been very successful through- of a diode or thyristor rectifier. ation and control is then performed inter- out industry. Instead of many nally and no communication is needed T individual drives being driven The fundamental building block of the with the external automation ➔ 1. separately, products such as ABB’s rectifier – six IGBTs and six freewheeling ACS800 multidrive handle multiple drives diodes – can be used for other purposes The PQ correction can also be used in and allow coupling between them. This is by implementing appropriate software. parallel with passive filters as a kind of important in processes like papermaking This article describes two of these: pow- hybrid compensator. This requires less where many drives have to be tightly cou- er quality (PQ) correction and intentional total investment, but the performance is pled to ensure good product quality all islanding. still as good as with full active correction. the way through the production process. These, and less-tightly coupled, applica- Power quality correction Compensating reactive power and har- tions benefit from the other advantages of The PQ correction abilities of the unit en- monic currents can reduce MV currents the ACS800 multidrive approach too, able reactive power compensation and significantly – 45 percent in one reference such as space savings; savings in ca- active harmonic filtering. Four of the most case. This means lower stress in MV bling, installation and maintenance costs; significant charac- reduced component count and increased teristic harmonic reliability; and the implementation of currents – the fifth, The fundamental building overall safety and control functions made seventh, eleventh possible by the common supply of the and thirteenth – block of the rectifier can be ACS800 multidrive. can be filtered ➔ 2. used for other purposes by The ACS800 multidrive has a rectifier PQ correction is implementing appropriate unit and two or more frequency convert- available at the ers connected to a common DC link ➔ 1. same time as the software. The most sophisticated type of rectifier unit is supplying unit is an IGBT (insulated-gate bipolar active power for the motor drives. The transmission lines and transformers, high- transistor) supply unit (ISU), which con- voltage and current measurement and er cosphi, lower levels of harmonic distor- sists of an active power stage similar to correction point can be on the low-volt- that of the frequency converter. This is age (LV) or medium-voltage (MV) side – capable of bidirectional active power whereby the latter is more beneficial be- Title picture flow, which enables regenerative energy cause it takes the reactive power of the ABB’s ACS800 provides sophisticated control of industrial motors, such as the one shown here. from braking to be fed into the grid. In transformer(s) into account. A dedicated But the ACS800 power electronics can be used addition, the harmonic distortion of such board performs voltage and current mea- for other tasks, too.

Multitalented 55 The PQ correction 2 Reduced harmonics 30 Ih abilities of the unit Ih_filtered enable reactive 25 power compensa- Decrease in harmonics tion and active 20 harmonic filtering. 15 Current (%) Current

0 THDI 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Harmonic number

tion and an increase in MV line loading generators. Energy storage dimensioning capacity. The decrease in reactive power depends on the topology used, actual can be directly equated to savings in the power required and reserve time. electricity bill. In addition, lower reactive power leads to lower voltage variation The energy storage can also be used and, thus, lower flicker index. to balance the active power intake from the grid if the industrial process is very Intentional islanding dynamic. The benefit of using energy The other control software discussed storage in a dynamic process is that a here enables the ACS800 power stage to smaller rectifier unit can be used, due to be used as an island converter – ie, to the lower peak power. produce robust sinusoidal three-phase voltage, similar to a rotating generator, for One main criterion in judging the perfor- the process. Intentional islanding is the mance quality of the island converter is deliberate sectionalization of the power the fault current capability. Now that the system during disturbances to create converter is part of the islanded grid, it power “islands” that maintain a continu- has to provide the fault current required to ous supply of power to a critical process. clear the fault and protect the equipment and personnel. The energy required for this can come from any DC source: eg, a rectified AC The island converter can run in parallel grid, wind turbine, diesel generator, solar with other island converters and in parallel cell, fuel cell or battery bank. The battery with the national grid. The number of par- storage can be connected straight onto allel converters is not limited – from the the DC link or through a DC/DC chopper. technical point of view any number can be The common DC link makes distribution of connected to supply a common island power to the process drives straightfor- grid. However, at some point, using a ro- ward. This same concept can be utilized in tating generator will be more beneficial smart grid applications where no transmis- than implementing a huge number of par- sion lines are available but there is a need allel converters. for electricity to provide power “islands.” In smart grid applications, the battery energy Other applications built storage is essential for balancing the dis- on DTC modulation tributed generator production and the The control of the two applications pre- island grid consumption ➔ 3. sented above is founded on the ACS800 software platform. In each case, the Usually, emergency power (from batteries) direct torque control (DTC) modulation is required to ride through a supply grid principle is used. DTC is an AC motor fault or to buy time to start diesel backup control method developed by ABB in

56 ABB review 2|14 3 Configurable power provision in smart grid application Power electronic Solar, Wind, National converters can be fuel cell hydro grid used to build an intelligent and highly reliable

DC link island grid. Island converter

Island grid DC/DC chopper

Diesel Battery

which all switch changes, for every con- supplies active power to large AC drives. trol cycle, are based directly on the elec- In addition, it compensates the reactive tromagnetic state of the motor; there is power of the entire test field and filters no separate voltage- and frequency-con- out the most significant characteristic trolled pulse-width modulator. The first harmonic currents. When running high- major successful commercial DTC prod- power six-pulse rectifiers in the test field, ucts were developed by ABB in the 1980s a reduction of 45 percent in MV current for traction applications. DTC relies heav- was measured when the PQ converter ily on digital signal processing and dedi- was enabled. This reduction in reactive cated electronics. The use of DTC allows power results directly in a savings of sev- special converter applications based on eral thousand euros per month in the ACS800 motor control to be developed. electricity bill. This development work is carried out by a dedicated ABB software team. The biggest island units in operation so far are two (for redundancy) 2.2 MVA liq- Benefits of scale uid-cooled converters operating in paral- All the applications mentioned profit from lel on a new Norwegian ship. The ship commonality. Each application has its also has two 0.9 MVA liquid-cooled island specific software, but the IGBT converter converters. These converters are part of module hardware remains the same. This multidrive systems. brings benefits of scale to prices, vol- umes, reliability, spare parts and global The applications described above show aftersales service. how ACS800 hardware, coupled with special software, can save energy, in- Size crease power quality and provide reliable The modular construction of the ACS800 power in the event of disturbances. Other product series is extremely beneficial and applications are just a matter of develop- flexible when building complicated con- ing the appropriate software. Given the verter applications. The smallest reason- capabilities of the technology, the number able module size in PQ and islanding and variety of new applications is expect- applications is 150 kVA in an R7i frame ed to increase. and the largest module size is 500 kVA. By paralleling these larger modules, a single converter with a rated power of about 5 MVA can be realized. Reijo Komsi ABB Discrete Automation and Motion, The largest PQ converter so far is a Drives and Controls 4.5 MVA liquid-cooled ACS800 multidrive Helsinki, Finland supply unit in a test field in Helsinki. It [email protected]

Multitalented 57 Hot spot

A new infrared STEPHAN WILDERMUTH, ULF AHREND, MORITZ HOCHLEHNERT, MARCO ULRICH – The generator circuit breaker (GCB) is of great importance for sensor measures the undisturbed operation of a modern power plant. It typically sits between a generator and its transformer to protect this equipment temperature in from damage, while handling very high currents – typically tens of kA. With such high currents, even a small increase of resistance in the generator circuit current-carrying path will lead to a large temperature increase in breakers the breaker – and this can have very dramatic effects. Temperature supervision is, therefore, essential. This, however, can be a very challenging task in the high-voltage (HV) environment so ABB embarked on a development program to produce a new temperature sensor system for GCBs.

58 ABB review 2|14 1 Pumped storage power plant application with HECPS-3S

GMS600 Sensor development and design ABB’s GMS600 is a GCB monitoring sys- A detailed technical analysis determined tem that indicates the need for mainte- that a temperature measurement scheme nance and provides early warning to based on the detection of infrared radia- CBs are used, for example, in avoid unexpected downtime ➔ 2. The tion (IR) was the best approach. The goal fossil-fueled, nuclear, gas-tur- GMS600 calculates remaining time-to- then was to take a commercially avail- bine, combined-cycle, hydro- overhaul based on cumulative current able IR sensor element and package it to G power and pumped-storage interruptions, total number of mechanical operate reliably in the demanding GCB power plants. They have a tough job. operations, time from last overhaul, cir- environment. During normal operation of the power cuit breaker main plant, the GCB has to carry the full nom- drive supervision, inal current of the generator, which can SF density and so 6 At such high currents, even easily reach 23 kA without bus cooling on. One aspect or over 30 kA with active cooling – all at missing from its a slight increase of electrical potentials of up to 32 kV ➔ 1. repertoire was temperature supervi- resistance in the current-car- At such high currents, even a slight in- sion. This was be- rying path leads to a large crease of electrical resistance in the cur- cause no commer- rent-carrying path leads to a large tem- cially available tem- temperature increase. perature increase. Increased resistance perature sensing can arise from connection misalignment, system fulfilled all dust inside the GCB or damaged contact the technical, commercial and functional The central component of the IR temper- surfaces. The consequent heating can requirements for an accurate and reliable ature sensor is the IR detector element lead to damage to internal silver-plated temperature monitoring of GCBs during itself. Non-cooled Si-based thermopile contact areas, such as the bus duct con- operation. detectors were chosen due to their good nection zones, the line disconnector and cost/performance ratio. The only way to the contact system of the interrupting This lack of a commercial system is not ensure proper performance of the sensor chamber. Heat removal from the main surprising as the temperature supervi- under the severe conditions encountered conductor is partly done by radiation, so sion of HV components can be challeng- in a GCB – spatial and temporal temper- paint with high emissivity is usually ap- ing. For example, the temperature ature gradients and high electromagnetic plied to the conductor – but this cannot sensor has to survive severe electromag- cope with significantly elevated tempera- netic conditions and can also be ex-

tures (normal operating temperatures are posed to steep temperature gradients Title picture in the range of 70 to 90°C). caused by, eg, desert climate. Accurate and reliable monitoring of the temperature in GCBs (ABB’s HEC8 is shown) is essential as the slightest increase in resistance can lead to a rapid Excess temperature can lead to loss of A new temperature sensor system had to temperature rise because of the very high currents interrupting capability or even provoke a be developed. flowing. How can temperature be monitored in such flashover if components start to melt. a challenging environment?

Hot spot 59 The goal was to 2 Central condition monitoring device GMS600 take a commer cially available IR sensor element and engineer it to operate reliably in the demanding GCB environment.

fields with fast transients – was to appro- the sensor package can be increased by priately package the IR detector and the giving the sensor and aperture a large electronics. thermal mass, and by reducing thermal

In addition to the detector ASIC, ad- The housing of the IR sensor ditional electronics were included to element was surrounded by a convert the digital SMBus output sig- material with high thermal nal to Modbus. conductivity. These electronics, too, must with- stand the severe EMI (electromagnetic conductivity around the sensor to delay interference) environment of a GCB. heat ingress to the sensor.

The sensor package, therefore, needs to The package is, therefore, a two-part- fulfill three major objectives: housing concept where the inner and out- – Suppression of large spatial tempera- er parts are thermally weakly coupled ➔ 3. ture gradients at the IR sensor This approach inherently satisfies the di- element electric and EMI requirements, too: The – Suppression of large temporal outer housing acts as a Faraday cage and temperature gradients at the IR the thermal insulation acts as an electrical sensor element insulator as well as a heat barrier. As an – Suppression of EMI additional EMI countermeasure, the outer housing is grounded through the GCB en- In order to fulfill the first objective, the closure and the inner housing is connected housing of the IR sensor element was to a local ground potential. surrounded by a material with high thermal conductivity ➔ 3. This ensures that Package dimensioning was defined by temperature gradients immediately equil- transient thermal finite element method ibrate and the thermal field around the (FEM) simulations of a simplified thermal sensor remains homogeneous. model ➔ 4. The design goal was to achieve a thermal time constant greater than 10 The second objective can be satisfied by minutes. This duration was predicted by choosing a design that leads to a large the simulation and verified by experimental thermal time constant (in the range of tests later on. several minutes). The time constant of

60 ABB review 2|14 3 Schematic of the cross section of the sensor package showing the main functional components The outer housing acts as a Faraday IR sensor element in PCB TO-5 package cage and the thermal insulation acts as an electrical screen as well as

Outer a heat barrier. housing Potting material

Insulating spacer Inner housing

Prototyping and testing of 30°C to 120°C at a constant ambient To check the thermal design and to verify (sensor) temperature of 25°C was test- good thermal coupling of the IR sensor ed. The sensor response displayed a lin- element to its surroundings, temperature ear behavior. The linearity error remained shock experiments were performed. The below 3°C over the entire object temper- IR temperature sensor was exposed to ature range. The variations (standard de- an ambient temperature change of 25°C viation) between the individual proto- to 70°C. The rise time of 5°C/min was types were found to be 0.8°C and 1.2°C limited by the heating power of the cli- at an object temperature of 75°C and mate chamber used. For the duration of 120°C, respectively.

A very important Large temporal temperature task for the IR temperature moni- gradients at the IR sensor toring system is the detection of element can be avoided by GCB overloading, choosing a design that leads when the temperature of the main to a thermal time constant of conductor can approach 120°C. This several minutes. scenario was simulated by changing the object temper- the experiment the IR temperature sen- ature range from 80°C to 120°C ➔ 5. The sor stared at a black-body radiator held IR sensor accurately captured this tem- at a constant 80°C. Very good sensor perature change and the measurement performance (error less than 2°C) was deviation stayed well within the required found if the thermal coupling to the inner accuracy interval of ± 3°C. housing was guaranteed by a thermal grease or adhesive. To assess the influence of changes in ambient temperature, the IR temperature To verify the performance of the IR tem- sensors were exposed to three consecu- perature sensor, 21 sensor prototypes tive temperature cycles from – 5°C to were built and subject to different envi- 60°C at a rate of 0.1°C/min. This rate of ronmental scenarios simulated by the temperature change was chosen to sim- climate chamber. Sensor response to a ulate a typical day/night scenario. black-body radiator temperature range

Hot spot 61 4 FEM simulation of the sensor package heating. This gives a first estimate of the thermal time The only way to constant of the whole sensor package and was used to define the package dimensions ensure proper performance of the 80 80 sensor under the 70 70 severe conditions 60 60 encountered in a 50 50

GCB was to ap- 40 40 propriately pack- 30 30 age the IR detec- 20 20 tor, the enclosure and the electron- 4a After 73 s 4b After 200 s ics.

80 80

70 70

60 60

50 50

40 40

30 30

20 20

4c After 400 s 4d After 600 s

Again, typical sensor measurement error Productization phase remained below 3°C. Furthermore, in The involvement of a potential manufac- humidity tests, the sensor measurement turer early on in the project resulted in a error was less than 2.5°C up to 90 per- very mature technology demonstrator. cent relative humidity, at an ambient Only a few changes were necessary for temperature of 60°C. full productization.

The IR temperature sensors were also Productization was done in parallel to tested for other disruptive factors en- the adaptation work on the sensor itself. countered in a GCB environment. This This covered the sensor assembly, cable included extensive vibration testing to harness design, mechanical integration simulate mechanical shock experienced of the sensors into the GCB enclosure, during GCB switching operations. Elec- routing of cables, and a GMS600 moni- tromagnetic immunity was tested ac- toring software update to log, store and cording to IEC 61000-4 and IEC 61000-6, present the temperature data to the cus- addressing immunity to RF electromag- tomer for nine sensors (three per phase). netic fields and electrostatic discharges, The supply chain was put in place in as well as electrical fast transient tests cooperation with the manufacturer, who (severity level 3 required). All tests were also preassembles sensors and cables successfully passed and the sensor sys- on a mounting rack to speed installation tem thus qualified for operation in a in the GCB. GCB.

62 ABB review 2|14 5 Climate chamber simulation of GCB overheating: IR temperature sensor response To check the ther-

140 140 mal design and to verify good thermal 120 120 coupling of the IR 100 100 sensor element to

80 80 its surroundings, Sensorsignal (˚C)

Object temperature (˚C)Object temperature temperature shock 60 60 experiments were 40 40 8 9 10 11 12 performed.

Time (h)

5a IR temperature sensor signal at an object temperature from 80°C to 120°C over several hours

4 +3 (˚C)

-2 Accuracy requirement

Measurement deviation (˚C)Measurement -3 (˚C) -4

-6 8 9 10 11 12

Time (h)

5b Measurement deviation stays well within the required accuracy interval of ± 3°C during the entire temperature ramp.

Extended service Access to this kind of condition data also Cost-efficiency can be significantly im- enables new service concepts and busi- proved by intelligent service approaches, ness models to be created, and provides such as predictive maintenance. However, valuable feedback for the design of new efficient, adaptive and sustainable predic- devices. Finally, statistical analysis of tive maintenance and equipment life strat- data from an entire fleet of devices can egies are highly dependent on meaningful reveal information unobtainable from a sensor signals from the field. single device. This opens up new oppor- tunities and value propositions for ABB The robust and cost-effective temperature to offer to end customers through its ser- Stephan Wildermuth sensor system described here enables reli- vice portfolio. Ulf Ahrend able temperature monitoring of GCBs dur- Marco Ulrich ing operation. In combination with other ABB Corporate Research sensor information (eg, vibration or contact Ladenburg, Germany ablation) a clear picture of a device’s health [email protected] condition can be derived and predictive [email protected] maintenance strategies formulated. This is [email protected] especially important for GCBs where overheating of the main conductor can lead to Moritz Hochlehnert the power plant shutting down, which can ABB Power Products, High Voltage Products result in high cost and potentially disas- Zurich, Switzerland trous equipment damage. [email protected]

Hot spot 63 64 ABB review 2|14 At a higher level

A medium-voltage-level UPS for complete power protection

SOPHIE BENSON-WARNER – ABB has developed a range of medium-voltage (MV) uninterruptible power supplies (UPSs) with ratings up to 6 MVA. Implementing a UPS at the MV level has many practical advantages and is an approach being adopted by customers in industry and in large data centers who have sensitive or critical loads. The PCS100 MV UPS range complements existing ABB low-voltage (LV) UPS and power conditioning products.

Title picture Moving the UPS up to the MV level has many advantages for industrial users and data centers.

At a higher level 65 1 The PCS100 MV UPS is suitable for protecting sensitive loads.

number of UPSs needed can present problems in terms of management, supervision, maintenance and availability. ur modern society now relies The solution is to install the UPS at the on the ready availability of a MV level. vast amount of data. Almost O every organization – health When installed at MV levels, the UPS authorities, banks, government depart- can be put in less-crowded spaces ments, retail outlets, corporations and away from the target devices – in MV so on – requires the safe storage electrical rooms or plant substations, of enormous amounts of information. for instance – thus freeing up space for Further, much industrial and domestic more important infrastructure, such as activity has become fully dependent on servers or manufacturing tools. a wide range of electrical devices. An added complication is the arrival on the ABB’s PCS100 MV UPS range is aimed power grid of an ever-increasing num- squarely at this market segment. It has ber of renewable generators that has been designed specifically to provide led to an increase in power-quality- related problems When installed at MV levels, like spikes, swells, sags, noise and the UPS can be put in less- harmonics that pose a risk to all crowded spaces away from power users. the target devices – in MV

The dependence electrical rooms or plant on a rock-solid supply of good- substations, for instance. quality power has driven the massive growth in the UPS clean, reliable and efficient power, and and power conditioner business in re- lower costs for customers in industry cent years. Traditionally, these devices and in large data centers who have sen- are fitted at the LV level, but this can of- sitive or critical loads. ten pose a challenge if the space available is limited. Also, where many devices are to be protected, the sheer

66 ABB review 2|14 2 An MV UPS can be configured to protect an entire data center 3 Single-conversion topology is a natural choice for MV. Power electronics load or just the mechanical loads. and power storage can remain at LV with transformer coupling to MV.

PCS100 UPS-I MV G G

LV switchgear LV switchgear

RPC RPC

LV DIST LV DIST

Mechanical load LV DIST I Load LV DIST II Mechanical load and cooling and cooling

The PCS100 MV UPS can be installed small system footprint minimize owner- to protect the complete supply or just ship costs. The fact that the energy stor- The PCS100 MV selected sensitive loads ➔ 1. In a data age and converter is at the LV level also center this could include the mechanical greatly simplifies maintenance and re- UPS can be in- loads ➔ 2. Installing the UPS protection duces system cost. Finally, the PCS100 at the MV level provides the most ener- MV UPS has many retrofit possibilities stalled to protect gy efficient configuration as the lower that allow custom designs that suit ap- the complete sup- currents at this voltage result in lower plications in plants that are currently un- losses. protected or where traditional rotary UPS ply or just selected solutions require replacement. The first release is rated up to 6.6 kV and sensitive loads. 6 MVA with even larger 15 kV class prod- Storage options ucts to follow (including 11 kV and Because the energy storage is kept at 13.2 kV options), rated at even higher LV levels, a wide range of energy stor- MVA. age options is available. The most common are ultracapacitors, lithium-ion bat- PCS100 MV UPS technology teries and high-discharge sealed The single-conversion topology used is lead-acid batteries. It is expected that a natural choice for MV as losses are ultracapacitors will be widely used in in- extremely small, meaning efficiencies dustrial applications due to their long well in excess of 99.5 percent can be life and compact size. For longer-auton- achieved. It also allows a system design omy applications, lithium-ion batteries where the power converter and energy similar to those used in electric cars storage can remain at LV, with a trans- offer reduced footprint and increased former coupling these to MV ➔ 3. Also at life when compared with the lowest- the MV level is a thyristor-based utility cost lead-acid solutions. Lithium-ion disconnect switch which prevents back- batteries have excellent cycle life char- feed into the grid in the event of a power acteristics and this opens up opportuni- loss or voltage sag. ties for smart grid support features, such as load shedding, to be added. Lower cost Up-front cost is always important in equipment selection, but the total cost of Sophie Benson-Warner ownership is usually the most important ABB Discrete Automation and Motion, cost criterion for the customer. The un- LV Power Converter Products paralleled efficiency of the PCS100 MV Napier, New Zealand UPS, its low maintenance costs and [email protected]

At a higher level 67 Boundaries of knowledge

Knowledge of boundary conditions is crucial for reliable simulations

KAI HENCKEN, THOMAS CHRISTEN – Partial differential equa physical processes that need to be taken into account is far tions (PDEs) are the basic language with which physicists richer than in the bulk. In addition, boundaries often govern describe many natural phenomena, such as electric and the result of a simulation even though they only occupy a magnetic fields, acoustics, fluid flow, and heat conduction. small part of the whole system. Hence, in obtaining mean The PDEs that describe the physics inside a spatial domain ingful numerical simulations, appropriate boundary condi of interest – so-called bulk equations – are the key elements tions can play a decisive role. Describing these mathemati in numerical simulations of ABB products [1]. However, at cally is, in general, not an easy task and requires a deep the boundaries of many systems the variety of underlying insight into the underlying physics.

68 ABB review 2|14 1 Derivation of boundary conditions for a macroscopic equation from the underlying microscopic physics

Extrapolated bulk solution y a y + b y’= c Solution of the macroscopic (bulk) equation

∆y

Solution of the (microscopic) boundary equation

L x

The first property is the order of the a relaxation process of the local polar- PDE, which indicates the highest spatial ization density. derivative that occurs in the bulk equation. For instance, the heat equation is There are other cases where a boundary of order two, as a derivative of the form condition is unnecessary, even if spatial 2 T / x2 occurs. The boundary condi- derivatives occur. For instance, the tions will, in general, be a relation be- state of a supersonic fluid at an outlet is DEs describe the behavior of tween the physical quantities and their completely determined by the informa- physical properties or quanti- (spatial) derivatives with an order small- tion coming from the bulk. Because the ties in space and time. Typical er by one than the order of the PDE fluid flows faster than the speed of P examples are the heat equation itself, because higher order derivatives sound, which is the information velocity for temperature, the Laplace equation can be eliminated with the help of the in this case, no information can flow for electric potential, and the fluid dy- bulk PDE. For instance, in the steady- backward from the boundary into the namics equations for mass, momentum state heat equation, 2 T / x2 = 0, the bulk. Hence, this boundary will not and energy flow. boundary condition might, in principle, affect the state in the bulk. contain arbitrary spatial derivatives, not The occurrence of (mathematical) spa- only T itself and its derivative. But terms Boundary conditions are usually neces- tial derivatives in these PDEs is associ- of the form “ 2 T / x2” or higher can be sary and are classified according to the ated with a coupling of a given point in eliminated using 2 T / x2 = 0. propagation behavior of the PDEs – dif- space with its surroundings, often due fusive, instantaneous, convective or to a transport phenomenon. In order to The second property concerns how in- wavelike. For example, instantaneous obtain well-defined, ie, unique, solu- formation propagates inside the bulk, ie, propagation corresponds to steady- tions of the PDEs, boundary conditions how a disturbance or change of a phys- state solutions, where one implicitly as- must be specified. This is similar to the ical quantity at one requirement for an initial condition in or- point influences its der to solve for a time-dependent pro- value at a distance For meaningful numerical cess – the conditions at the starting at the same or a time of a simulation can be interpreted later time. simulations, bulk models as a boundary condition for the time axis, as an analogy. The general mathe- The simplest ex- have to be complemented matical form of specific boundary con- ample is a PDE with appropriate boundary ditions mainly depends on two struc- of order zero. Spa- tural properties of the bulk equations. tial derivatives and conditions. propagation are then absent and boundary conditions sumes that the propagation and, there- are superfluous. The equation is, in this fore, the equilibration, in the system is case, a (distributed) system of ordinary much faster than the timescale consid- Title picture differential equations (ODEs) rather than ered. An example is the formation of an Products contain many internal boundaries, a PDE. A physical example of this is the electric field (eg, in a vacuum), which is surfaces and interfaces that strongly determine their performance and which must be described electric polarization induced in a dielec- usually described by the instantaneous in simulations by boundary conditions. tric medium, which can be described by Laplace equation.

Boundaries of knowledge 69 2 Ohmic contact

U=0

+ U>0 M + + M +

+ d d

M M

2a Insulator without intrinsic, but with injected, charge carriers 2b Application of a voltage tilts the energy potential seen by the carriers, (here positive holes) from the two attached electrode contacts. leading to a maximum near the injecting electrode. (Blue: equilibrium potential.)

are derived by averaging quantities, like The boundary con- thermal energy, over small volume elements in which these quantities are ditions have to be considered homogenous. At boundaries, the properties change abruptly, formulated in a way making consideration on a shorter, eg, that makes the microscopic, scale necessary. As a consequence, boundary condition modeling model well-posed, must take physics at a higher level of detail and greater variety of phenomena ie, a physically rea- than the bulk equation into account. sonable solution An important example of this is repre- exists. sented by bulk equations for a gas under the assumption of local thermodynamic equilibrium, where the temper- Transients can in practice often be dis- ature is well-defined and the velocities regarded due to the fact that the electric of the particles follow the Maxwell distri- field travels with the speed of light. bution. When approaching the boundary, this velocity distribution deviates The boundary conditions have to be for- from the one in the bulk due to surface mulated in a way that makes the model effects and thermodynamic equilibrium well-posed – ie, a physically reasonable is no longer a given ➔ 1. In other words, solution exists. This can impose restric- the macroscopic equations for the tions on the number and types of condi- physical quantity y (x, t) along the x-axis tions that are needed at each boundary. of ➔ 1 are valid for distances larger than a certain microscopic length L, but not Boundary condition physics below it. The magnitude of this bound- goes beyond bulk physics ary region is assumed to be much As mentioned, the bulk equations con- smaller than the scale that is resolved in strain and prescribe the functional form the numerical simulation. The extrapola- of the boundary conditions. However, tion of the bulk solution to the boundary the values of the coefficients or param- does not necessarily coincide with the eters occurring in them are still free and microscopic solution. However, the need to be determined by the underly- boundary condition has to fulfill the ing physics. This can be a sophisticated mathematical relation set by the bulk task, as boundary conditions need a equation. more detailed view into the physical system than the bulk PDEs. Bulk PDEs

70 ABB review 2|14 3 An electric arc burning between two electrodes. The arc root forms an interesting and complex boundary.

In this case it is given by a general rela- DC conduction in insulators tion of the form In AC cables, the 50 Hz field distribution is usually calculated by solving a La- a y + b y’= c place equation for the electric potential in the dielectric materials, with appropri- The coefficients a, b and c must be ob- ate boundary conditions on the con tained by enforcing a smooth transition ductive parts. The relevant material from the microscopic to the macroscop- property is the dielectric permittivity and any accumulation of charges within The underlying physics that the dielectric materials can be ne- needs to be taken into ac- glected.

count at boundaries is much Field calculations richer than for bulk equations. in DC insulation, however, are con- siderably more ic solution. For instance, even if the fun- complex because space charges can damental microscopic physics calls for build up inside the material. By this, y = 0 at the boundary (x = 0), the macro- sometimes very slow, process, the field scopic boundary condition may exhibit distribution may change significantly a discontinuity due to the physics in the over time. An illustrative example of the microscopic boundary layer. An impor- coupled interaction of the boundary tant example is a slip boundary condi- with the bulk is the formation of a tion for the (macroscopic) gas flow space-charge-limited current (SCLC): velocity in a pipe, where one assumes Consider a material that is initially bare a finite velocity all the way to the wall, of any charge carriers and with a metal although microscopically, ie, in a very contact on each side ➔ 2. Even without thin viscous boundary layer, it rapidly an applied voltage, charge carriers (posi- decreases to zero at the wall. tive holes, say, for simplicity) will diffuse from the electrodes into the insulator.

Boundaries of knowledge 71 4 A number of physical phenomena occur in an arc root – only the microscopic view shows the interdependency between them.

Thermofield emission Electrons

Absorption Ions Arc (plasma) Cathode (arc root) Cathode (arc

Atoms Evaporation

Mass flux

Heat flux

Electric current

property of vanishing field under these Charge injection conditions are named “ohmic electrodes.” Because the electric current – from electrodes which is proportional to the product of the electric field, the charge carrier den- can be of great sity and their mobility – remains finite, a relevance when vanishing electric field together with a nonzero current implies that the charge designing HVDC carrier density diverges (becomes infi- nite) at the virtual electrode. In reality, cable and the density remains, of course, finite accessories. due to the action of diffusion, which was, in this simple picture, neglected. The electrode injects a large number of There, they create a thin charge accu- charge carriers, leading to such a large mulation layer that leads to an in- charge density at the contact that the creased, almost flat, potential distribu- electric field is suppressed. This can tion in the interior of the insulator. The lead to a field enhancement at another electric field, which is essentially the place or after polarity reversal. negative slope of the potential, is thus practically zero everywhere between the Charge injection and accumulation is of plates, except near the contacts ➔ 2a. great relevance when designing HVDC A high voltage applied across the elec- insulation devices. A main consequence trodes induces a strong tilt of the poten- of it is that the electric field distribution tial that leads to a potential maximum is then not only determined by a bulk near one of the electrodes ➔ 2b. conductivity, but is also influenced by contacts and the boundary between Typically, this distance is too small to be them, which requires special measures resolved in the macroscopic simulation to make HVDC insulation robust [2]. and is excluded. But this maximum has important consequences. The electric Arc roots in vacuum circuit breakers field is zero at the maximum, as it is, by In vacuum circuit breakers (VCBs), the definition, the slope of the potential. interruption of currents occurs via the This location is called the “virtual elec- formation and extinction of an electric trode” and electrodes that exhibit this arc [3] ➔ 3. First of all, as the bulk mate-

72 ABB review 2|14 Circuit breakers rely strongly on boundary effects – for example, metal vaporization in vacuum breakers and nozzle ablation in gas circuit breakers. rial here is vacuum, the relevance of ap- Further examples are to be found in propriate boundary conditions is obvi- sensors, oil-insulated HV equipment ous because the metal plasma in the and so on. VCB completely originates from the electrodes. Secondly, the example pres- Reliable simulation ents a complex multiphysics boundary For meaningful numerical simulations, problem, since a number of different bulk models have to be complemented physical phenomena are involved that with appropriate boundary conditions. can be treated independently in the bulk, Boundaries often have a substantial but are connected at the lower level. effect on the result even though they only occupy a small part of the whole Arc roots are the areas where the arc system. Furthermore, the variety of under connects to the metal electrodes. An lying physical processes that need to be electric layer is formed at an arc root. taken into account in boundaries is This non-neutral sheath leads to a volt- much richer than in the bulk, whose age between the bulk of the plasma and equations often follow from simplifying the electrode – ie, the electrode voltage conservation laws. drop, similar to what is shown in ➔ 2a. This voltage drop leads to a strong elec- It is wise, when validating simulation re- tric field at the surface. This is needed sults, to scrutinize the boundary condi- to draw a large electric current from the tions used, for two reasons: First, due metal to the plasma by making elec- to their large effect, it is sometimes easy trons leave the cathode or enter the an- to produce the desired results by tuning ode and by making ions move to the boundary condition parameters. Sec- surface ➔ 4. This ion movement and re- ond, the physics behind boundary con- combination is the dominant heating ditions is often very complex and can be mechanism for the metal. The electrode treacherous. Choosing a good bound- surface in the arc root becomes so hot ary condition is not an easy task and that metal evaporates. The vacuum arc requires a deep insight into the underly- is actually a metal vapor arc that feeds ing physics, but the effort pays off by itself purely from the material emitted delivering much more reliable simulation from the arc roots. The balance of the results. Last but not least, an under- surface heating from the plasma and the standing of the governing boundary cooling by metal evaporation deter- physics can be an important source of mines the electrode temperature and, technical innovation. by this, the performance of the breaker.

Each of these processes is complex in Kai Hencken itself, but, because the same particles Thomas Christen (electrons, ions and atoms) are the car- ABB Corporate Research riers of different properties (mass, heat Baden-Dättwil, Switzerland and electric current), the boundary con- [email protected] ditions are interrelated and this has to [email protected] be taken into account if a consistent simulation is to be obtained. Reference [1] ABB Review 3/2013: Another example of the relevance of Simulation, 2013, pp 1–84. boundary effects is found in arc-radia- [2] T. Christen, “Characterization and Robustness tion-induced material ablation in gas cir- of HVDC Insulation,” in IEEE Conference on Solid Dielectrics, Bologna 2013, pp. 238–241. cuit breakers, which is relevant for the [3] I. Kleberg, W. Shang, “Understanding arcing: pressure buildup needed in the switch- Simulation of high-current vacuum arcs,” ing process [1]. ABB Review 1/2004, pp. 22–24.

Boundaries of knowledge 73 Pushing the limits

KWOK-KAI SO, BENT PHILLIPSEN, MAGNUS FISCHER – Computational fluid Turbine simulation dynamics (CFD) has matured and is now an indispensable tool for for next-generation turbomachinery design and development. In particular, aerodynamic analysis and optimization of axisymmetric rotors and stators based on turbochargers CFD has become a standard procedure in the development process. Measurements of turbocharger turbines on a test rig have indicated that distortion of the symmetric flow at the inlet and the outlet of the turbine can have a significant influence on turbine performance. Based on CFD simulations of the complete turbocharger turbine from inlet flange to outlet flange, this influence was confirmed and a turbine geometry less sensitive to the distortions was found. These simulations have pushed the limits of the application of CFD to turbine design.

74 ABB review 2|14 1 Computational model of the turbine stage. Left to right: intake manifold, nozzle ring, rotor and exhaust manifold.

2 Turbocharging multiplies power

ABB is at the helm of the global industry in the A typical turbocharger consists of two main manufacture and maintenance of turbocharg- systems ➔ 3: the turbine stage (orange ers for 500 kW to 80+ MW diesel and gas section in figure) that recovers the power from engines. ABB’s technology and innovation the diesel engine exhaust gas; and the enables customers’ equipment to perform compressor stage (blue section) that boosts better and produce fewer emissions, even in compressed air to the diesel engine. With a the toughest environments. Approximately turbocharger, a diesel engine delivers four 200,000 ABB turbochargers are in operation times the output power a naturally aspirated across the globe in ships, power stations, engine would. In other words, the turbo- gensets, diesel locomotives and large, charger multiplies engine power. In addition, turbocharger for a high-pow- off-highway vehicles. ABB has over 100 Ser- turbocharging technology is the main driver

er application typically has an vice Stations in more than 50 countries and for the reduction of fuel costs and NOX axial turbine stage that in- guarantees original parts and original service. emission in diesel and gas engines. A cludes a nozzle ring and a rotor. The turbocharger’s intake manifold directs the gas flow into the axial turbine stage upstream of the nozzle ring. The turbine stage and the manifolds is not gas expands in the turbine stage and The flow through taken into account. drives the rotor. Downstream from the rotor, the exhaust manifold functions as the components The challenge in turbine-stage simulation a diffusor – an element critical to the per- must be engi- arises when the intake manifold and the formance of the turbine stage ➔ 1– 2. The exhaust manifold exhibit severe turns gas flow through the turbocharger com- neered to ensure and radial bends, due to spatial require- ponents must be engineered to ensure ments. In this case, the assumption that maximum turbine performance and, in maximum turbine the inflow and outflow paths are axially this regard, CFD plays a critical role in symmetric no longer holds. These flow the development of turbochargers. performance and, deviations can have a significant effect in this regard, on the diffusor and turbine performance Challenges in turbine simulation as undesired flow recirculation and sepa- Conventional CFD simulation of an axial CFD plays a criti- ration can occur in the diffusor region turbine stage is usually performed on and result in a drop of turbine efficiency. two components, namely the nozzle ring cal role. Up until now, finding a suitable diffusor and the rotor. Typically, only the flow in- involved several design iterations with side one segment of the nozzle ring and manifolds are carried out in a separate, extensive test runs. the rotor is simulated – the simplification standalone process. The advantage of of a periodic axisymmetric flow condition this sequential design approach is the In order to investigate the flow of the is assumed. Traditionally, the simulation relatively low computational demand of axial turbine stage with various intake or and design of the intake and exhaust flow simulation for one channel of the exhaust manifolds without having to test nozzle ring and the rotor. Also, the ap- these design variants on the turbine test proach works well for regular axial inflow rig, multicomponent CFD simulations and outflow conditions. However, the can be performed. In this regard, simula- Title picture simulation of the manifolds alone, with- tions of the radial intake manifold togeth- How can the full capabilities of CFD be exploited to make the design of turbines in turbochargers out the turbine stage, is not a complete er with the nozzle ring were conducted even better? simulation as the interaction between the to study inflow inhomogeneity originating

Pushing the limits 75 The challenge 3 ABB turbocharger A175-L associated with a multicomponent CFD simulation is the higher computational demand due to the full 360° computational domain.

from the radial intake manifold – in par- studied in detail. Furthermore, because ticular, the flow performance in the diffu- the CFD simulation of the full turbine sor within the exhaust manifold under stage from inlet flange to outlet flange nonaxisymmetric inflow and outflow con- corresponds to the configuration in the ditions. The challenge associated with a standard test bench measurement, nu- multicomponent CFD simulation is the merical CFD results can be validated higher computational demand due to the against experimental measurements. full 360° computational domain that is now required because the axisymmetric For flange-to-flange simulations howev- flow assumption no longer holds. As is er, a balance must be struck between the case generally in multicomponent computational effort and solution accu- CFD simulations, suitable mesh match- racy when investigating the influence of ing, numerical models appropriate for nonaxial inflow and outflow conditions.

High-fidelity CFD The challenge in turbine-stage to the rescue Given the objec- simulation arises when the tive of flange-to- flange simulations, intake manifold and the ex- the CFD meshes, haust manifold exhibit severe needed for the numerical calculation turns and radial bends. and the models, must be defined accordingly. A spe- multicomponent situations and reliable cific meshing tool that can cater for the definition of boundary conditions are all vane and blade geometry in the turbine essential. nozzle ring and the rotor is employed there ➔ 4, while a general-purpose mesh- Despite these challenges, multicompo- ing tool is adopted for the intake and nent CFD simulations do offer the oppor- exhaust manifolds, where its flexibility tunity to gain insight into the flow across allows it to efficiently tackle the various different components. In particular, the curved profiles. coupled effect at the turbine rotor exit on flow conditions in the diffusor can be

76 ABB review 2|14 4 CFD mesh adaptions As the CFD simu lation of the full turbine stage corresponds to the configuration in the standard test bench measure-

4a Nozzle vane 4b Rotor blade ment, results can

5 The turbine stage on a test bench be validated against experimental measurements.

In the steady-state CFD simulations, the high-performance computing (HPC) Results delivered by CFD Reynolds-averaged Navier-Stokes equa- cluster so that the simulations of various Different scenarios were simulated by the tions serve as the flow-governing equa- components in different operating and CFD model. These scenarios involved tions. The k-ω shear stress transport test conditions can be conducted within different designs and combinations of the model, in conjunction with a wall function a few weeks. nozzle ring, turbine rotor, intake manifold approach, is adopted to predict the tur- and exhaust manifold, as well as different bulence, onset and amount of flow sepa- Physical validation operating conditions and cold-gas and ration. The CFD simulation is set up so Setting up and running the simulation hot-gas test conditions. as to avoid resolving small-timescale model is only half the story: The simula- transient effects. tion results must be validated against In general, there was very good agree- physical observations, typically test mea- ment between the test measurements The stationary nozzle ring and rotating surements, to ensure that they accurate- and the CFD simulations of the turbine- turbine wheel of the computational do- ly describe the physical phenomena. stage characteristic quantities ➔ 6. Be- main are coupled by a so-called frozen- cause the CFD simulations are verified rotor domain interface model. This inter- In the test facility ➔ 5, an extensive list of and validated against test measurements face model is an efficient algorithm for turbine-stage characteristic quantities, for a number of configurations, good computing a steady-state CFD solution including static and total states of pres- insight into the flow conditions in the tur- for stationary and rotating parts. sure and temperature at various loca- bine stage from the inlet flange to the tions of the turbine, mass flow rate, tur- outlet flange can be gained ➔ 7. The CFD model and setup above is bine work, turbine power and turbine based on a widely-adopted industrial stage efficiency, can be measured. This As an example, a radial intake manifold CFD platform, the accuracy of which is provides an excellent setting to accu- and a 90° turn in the exhaust opening in already verified. The computational do- rately define the boundary conditions in the exhaust manifold can be simulated. main typically consists of around 20 mil- the CFD model and to form the basis for With this configuration, there is a high lion cells and nodes. The large-scale comparison and validation of the CFD potential for undesirable flow separation simulations are carried out on an ABB simulation results. and recirculation in the diffusor region.

Pushing the limits 77 6 Comparison of selected characteristic quantities from test measurements (blue) and 7 Streamlines from inlet flange to outlet flange. CFD simulation (grey) The streamline color indicates flow velocity.

220 1,600

170 1,200

120 800 Turbine power (kW) Turbine Turbine work (kJ/kg) Turbine 70 400 1 2 3 4 1 2 3 4 Test configuration Test configuration

95 8 90 7 85 80 6

75 flow rate (kg/s) Here: Turbine mass mass Turbine Here: Turbine efficiency (%) efficiency Turbine 70 5 1 2 3 4 1 2 3 4 Test configuration Test configuration

8 Streamlines for different exhaust manifold designs

8a Planes of interest 8b Undesired flow separation and recirculation 8c Desired expansion in diffusor in diffusor

As was revealed in test measurements, manifolds, and the adverse inflow and the performance of the turbine stage outflow conditions. deteriorates under certain operating conditions due to nonsymmetrical inflow Outlook beyond limit conditions. The drop in turbine efficien- At ABB, CFD is being used to advance cy can be captured and reproduced by understanding in new areas of turbo- CFD simulations, and the flow condi- charging technology – for example, heat tions inside the diffusor can be further transfer simulation and thermal analysis analyzed by studying the CFD simula- for cooling design and material selection, tions ➔ 8. As an illustration, the plane as well as acoustic simulation for noise susceptible to flow separation and recir- reduction. In parallel, the ABB develop- culation inside the diffusor is highlighted ment facility – CFD simulation tools, test Kwok-Kai So in ➔ 8a. Exhaust manifolds with different center and HPC cluster – are continu- Bent Phillipsen diffusor designs can be simulated to ously being improved. Through these ef- Magnus Fischer identify those that avoid flow separation forts, the next generation of turbocharg- ABB Process Automation, Turbocharging inside the diffusor region ➔ 8b–8c. In this ers will be created. Baden, Switzerland way, turbine performance can be main- [email protected] tained even under the restrictions im- [email protected] posed by the radial intake and exhaust [email protected]

78 ABB review 2|14 Editorial Board

Claes Rytoft Chief Technology Officer Group R&D and Technology

Ron Popper Head of Corporate Responsibility

Eero Jaaskela Head of Group Account Management

Andreas Moglestue Chief Editor, ABB Review

Publisher ABB Review is published by ABB Group R&D and Technology.

ABB Technology Ltd. ABB Review Affolternstrasse 44 CH-8050 Zurich Switzerland [email protected]

ABB Review is published four times a year in English, French, German, Spanish and Chinese. ABB Review is free of charge to those with an Preview 3|14 interest in ABB’s technology and objectives. For a subscription, please contact your nearest ABB representative or subscribe online at www.abb.com/abbreview Mining Partial reprints or reproductions are permitted subject to full acknowledgement. Complete reprints require the publisher’s written consent. Our tiny blue planet is endowed with a huge variety of elements and minerals, many of which humans have found ingenious uses Publisher and copyright ©2014 ABB Technology Ltd. for. Attitudes to mining activities can be mixed and discussions Zurich/Switzerland are often controversial. But most material of commercial signifi-

Printer cance, including those making up the objects around us, were in Vorarlberger Verlagsanstalt GmbH some way at some point extracted from the Earth’s crust, or AT-6850 Dornbirn/Austria otherwise manufactured using equipment that was itself made of Layout such materials. Mining is a pivotal but often undervalued aspect DAVILLA AG of human existence. Zurich/Switzerland

Disclaimer ABB’s presence in the mining industry spans a broad range of The information contained herein reflects the views different fields. It ranges from the electrical supplies that keep it of the authors and is for informational purposes only. Readers should not act upon the information all powered, to mechanical items such as hoists and ventilators contained herein without seeking professional as well as the drives that control them. It also encompasses advice. We make publications available with the instruments, control and monitoring systems as well as numerous understanding that the authors are not rendering technical or other professional advice or opinions other aspects. on specific facts or matters and assume no liability whatsoever in connection with their use. The companies of the ABB Group do not make any Issue 3/2014 of ABB Review will be dedicated to ABB’s contribu- warranty or guarantee, or promise, expressed or tion to the field of mining. implied, concerning the content or accuracy of the views expressed herein. ABB Review on the tablet

A tablet version of ABB Review is available. To access this, please

ISSN: 1013-3119 visit http://www.abb.com/abbreview www.abb.com/abbreview Stay informed . . .

Have you ever missed a copy of ABB Review? There is now an easy way to be informed every time a new edition of ABB Review (or special report) is published. You can sign up for the e-mail alert at www.abb.com/abbreview

Preview 79 Times are changing. Quality remains.

Check out our new ABB Review app. Available in four languages, the app features interactive functionality for your tablet and smartphone, fully searchable content, slideshows, movies and animations. http://www.abb.com/abbreview