Evaluation of Test Cycles for Freight Locomotives MATTIAS SKOGLUND Licentiate Thesis Stockholm, Sweden 2011 TRITA-EE 2011:060 ISSN 1653-5146 ISBN 978-91-7501-102-8 Electrical Machines and Power Electronics School of Electrical Engineering, KTH Teknikringen 33 SE-100 44 Stockholm SWEDEN Akademisk avhandling som med tillstånd av Kungliga Tekniska högskolan framlägges till offentlig granskning för avläggande av teknologie licentiatexamen i elektrotekniska system 29 september 2011 klockan 13.15 i sal D41, Kungliga Tekniska högskolan, Lindstedtsvägen 17, Stockholm. © Mattias Skoglund, September 2011 Printed by Universitetsservice US-AB Abstract Diesel locomotives provide versatility to the railway system as they do not depend on electric feeding. Worldwide they constitute important parts of locomotive fleets used for various tasks such as mainline services, shunting and terminal operations. The main drawbacks are emissions of CO2, NOx and other pollutants. The emissions to air are in general controlled by legislation. The European testing and approval procedure for locomotive engines is performed with the ISO 8178-F test cycle. It is alone meant to resemble all European locomotives. Good correlation was found between mainline operations and the ISO 8178-F test cycle. A good correlation was furthermore found between shunting operations and North American shunting test cycles. However, this thesis has shown that this results in inadequate description of for instance shunting operations. Typical characteristics for shunting are relatively high ratio of transient loading, low mean power output and high amount of idling. Therefore important aspects of diesel locomotive usage are thereby disregarded in certifications. Deficient correlation between test cycle and intended operations may lead to locomotives that are not properly optimised for the type of operation they are intended for. Improperly dimensioned and optimised locomotives cause impaired fuel economy and more emissions emitted. Many Swedish diesel locomotives are to a large extent used in shunting-like conditions in yards and industries for instance. Therefore, it is recommended to supplement the present ISO test cycle with a test cycle that includes the characteristic of shunting. Knowledge about duty cycles for specific operations can be of importance in locomotive acquisition, dimensioning of new locomotives or when estimating emissions and/or fuel consumption. It is essential to make proper dimensioning of propulsion systems as it can imply lower life cycle costs as well as fewer emissions. Appropriate dimensioning of the propulsion system is particularly important for non-conventional propulsion systems. If the application range of a test cycle is narrow, its emulating capability ought to be better at describing and representing the indented application. Today's test cycles state fractional power or torque as a function of engine speed. This may result in misleading duty cycles when the same kind of operation is undertaken with different locomotives that have widespread power ratings. A more powerful locomotive used for the very same load as a less powerful locomotive will result in a different duty cycle. Non-conventional propulsion systems are gaining popularity also in the railway industry where implementation of new technology usually is slow. Dual mode and hybrid systems are two examples. Related to test and duty cycles the build-up of these new propulsion systems change the prerequisites of the propulsion systems. From a duty cycle perspective it is reasonable to implement an additional test cycle for non-conventional propulsion systems if the popularity rises. Keywords: Duty cycles, Test cycles, Diesel locomotives, Locomotive emissions, Dual modes, Hybrid systems i ii Preface and acknowledgement The licentiate thesis work was started in 2006 as an incentive to examine the nature of locomotive duty cycles. The financial support from Trafikverket, formerly Banverket, the Swedish Transport Administration is hereby gratefully acknowledged. I would firstly like to thank my supervisors Professor Stefan Östlund at KTH and Dr. Peter Bark at TFK for support and assistance. Measurements of locomotive duty cycles were carried out in the autumn of 2008. It was made possible by help and support from Green Cargo and especially Anders Gustafsson. Matts Risberg supported the planning and the engineers guaranteed, thank you all, safe driving. I would also like to thank Jan Wännman at Interfleet for carrying out the measurements, providing measurement data and also for problem solving abilities when such occurred. Finally I would like to thank my beloved family, Sara and Valdemar for invaluable support. Stockholm, August 2011 Mattias Skoglund iii Table of contents Abstract ....................................................................................................................... i Preface and acknowledgement ................................................................................ iii Table of contents ....................................................................................................... iv 1 Introduction ............................................................................................................. 1 1.1 Background to research area ............................................................................................ 1 1.2 Test cycles and duty cycles ............................................................................................... 3 1.3 Scope of work and method .............................................................................................. 3 1.4 Previous research ............................................................................................................... 3 1.5 Research questions ............................................................................................................ 4 1.6 Outline of the report ......................................................................................................... 5 1.7 Publications ........................................................................................................................ 5 2 Characteristics of rail freight operations ................................................................. 7 2.1 Performance of a locomotive .......................................................................................... 7 2.2 Operation ........................................................................................................................... 7 2.3 Locomotive efficiency ...................................................................................................... 8 3 Underlying components and their usage .............................................................. 11 3.1 Internal combustion engines .......................................................................................... 11 3.2 Diesel locomotives for freight service .......................................................................... 13 3.3 New locomotive concepts .............................................................................................. 15 4 Test cycles.............................................................................................................. 21 4.1 Test cycle classification ................................................................................................... 22 4.2 Test cycle development and application ...................................................................... 26 4.3 Existing test cycles .......................................................................................................... 27 4.4 Duty cycles in alternative propulsion concepts ........................................................... 31 4.5 Test cycle modelling ........................................................................................................ 31 4.6 Energy and emission examples ...................................................................................... 33 4.7 Discussion – measurement objectives .......................................................................... 37 iv 5 Measurements........................................................................................................ 39 5.1 Objectives of the measurement ..................................................................................... 39 5.2 Equipment characteristics .............................................................................................. 41 5.3 Mainline measurements .................................................................................................. 45 5.4 Measurement limitations ................................................................................................ 48 5.5 Shunting measurements .................................................................................................. 58 5.6 Additional data analysis .................................................................................................. 64 5.7 Concluding remarks from the measurements ............................................................. 69 6 Conclusions ........................................................................................................... 71 6.1 Discussions ....................................................................................................................... 71 6.2 Implementation of the results ....................................................................................... 74 6.3