William Liu

At KTH, I work as a permanent researcher and Docent (Associate professorship) in railway vehicle technology with focus on energy and sustainability.

I have been working and researching in the railway field since 2008. I have joined the system development and commissioning testing of several high-speed railways. To make rail transport more reliable, more affordable and more attractive, so far I have participated in more than 20 railway-related research projects and published almost 70 publications (conference and journal articles) about research on rail transport systems. My research interests cover traction and braking, application of renewable energy, driving optimization, pantograph-catenary dynamics, train thermal comfort, climate adaptation, circular economy, emerging guided transport system and digital rail lab.

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Work experience:

• Permanent researcher in Rail Vehicle Technology, KTH Royal Institute of Technology, Stockholm. 2020.01 - now
• Docent (Asscociate Professorship) in Rail Vehicle Technology with focus on energy, KTH Royal Institute of Technology, Stockholm. 2025.05
• Member of Swedish Electrical Standardization Committee (SEK Svensk Elstandard). 2020.06 - now
• Member of Svenska Mekanisterna. 2022.12 - now
• Postdoc Researcher in Rail Vehicle Technology, KTH Royal Institute of Technology, Stockholm. 2017.12 - 2019.12
• Assistant Researcher at China Academy of Railway Sciences (CARS), Beijing. 2011.06 - 2013.05
• Research Engineer at China Academy of Railway Sciences (CARS), Beijing. 2009.06 - 2011.05
• Intern at China Academy of Railway Sciences (CARS), Beijing. 2008.

Education qualification:

• Doctor of Philosophy in Vehicle Engineering, KTH Royal Institute of Technology, Stockholm. 2017.11
• Licentiate of Technology in Vehicle Engineering, KTH Royal Institute of Technology, Stockholm. 2015.10
• Master of Science in Mechanical Engineering, Tianjin University, Tianjin. 2009.06
• Bachelor of Science in Mechanical Engineering, Harbin Institute of Technology, Harbin. 2007.07

Teaching:

• Rail Vehicle Technology (SD2307), master level, Teacher
• Vehicle System Technology (SD2221), master level, Teacher
• Energy System (MJ1145), bachelor level, Teacher
• Energy Technologies for Sustainable Transport (MJ2506), master level, Teacher
• Vehicle Engineering (SD1002), bachelor level, Teacher
• Railway system and rail vehicle technology, Professional education for industry, Teacher
• Vehicle dynamics project course part I (SD2229), master level, Teacher
• Vehicle dynamics project course part II (SD2230), master level, Teacher
• Rail system perspective, doctoral level, for PhD students at four Swedish railway research centres, Teacher
• KTH Delsbo Electric Team, Advisor

 

Supervision:

• Bachelor's theses (7)

1. Jakob Lindbergh and Hector Älfvåg, Optimering av tågs kontakt med kontaktledning – utplacerade massors påkerkan på kontaktkraftens kvalitet, 2019.
2. Alice Zhang and Gustav Ström, Delsbo electric: Design och tillverkning av bottenplatta till ett rälsfordon, 2022.
3. Ludvig Danström, Delsbo electric: Optimering av fjäder-dämpar system, 2023.
4. Olof Skagerlind and Gabriel Forsling, Delsbo electric: Optimering av hjuldesign, 2023.
5. Oliver Rehn, Delsbo electric: Energiförbrukning & köroptimering, 2024.
6. Henric Molin and Anton Säll, Energiförbrukningen vid
   framdrivning av ett Hyperloopsystem, 2025.
7. Darian Rafiq and Aboud Shammo, Termisk analys av Hyperloop:
   Utmaningar och lösningar, 2025.

• Master's theses (16)

1. Philipp Geiberger, Monitoring energy efficiency of heavy haul freight trains with energy meter data, 2021.
2. Alexandra Jerresand and Micaela Diamant, Energy usage of smart wayside object controller, 2021.
3. Filipp Zarov, Life cycle cost of smart wayside object controller, 2021.
4. Gaston Holmström, Pantograph-catenary wear modelling using dynamic simulation, 2022.
5. Sidharth Kapoor, Energy usage of railway wayside object heating, 2022.
6. Jimmy Liden, Optimization of comfort-related energy of Stockholm commuter trains, 2023.
7. Siddharth Sumathi, Modelling of heat transfer of railway switch heating, 2023.
8. Yijing Pang, Optimization of traction energy of Stockholm commuter trains, 2023.
9. Gökmen Dursun, Cost modelling of optimizing train operation and upgrading infrastructure for decision-making, 2024.
10. Kangli Chen, Modelling of power supply systems of Stockholm local rail transport, 2025.
11. Danlin Fang, Study on train driving strategies in virtual coupling operation, 2025.
12. Yinan Yang, Circular economy: Quantifying railway sustainability, 2025.
13. Yi Yang, Computer vision-based crack and damage detection, 2026.
14. Boyang Chu, Modelling and simulation of traction noise of electric train, 2026.
15. Xinrui Li, Study on climate finance of alternative drives for rail transport, 2026.
16. Tiiuon Yeldo Mathew, Study on the impact of Industry 5.0 on railway transport, 2026.

• Doctoral students:

1. Yan Xu, Rail vehicle dynamics under adverse conditions, 2021.02 - 2022.09. (finished)
2. Yanjun Zhang, Braking system of rail vehicle, 2021.09 - 2025.12. (finished)
3. Bastian Schick, Pantograph-catenary dynamic interaction, 2021.03 - 2026.12. (expected)
4. Yingjie Dong, Application of artificial intelegence for infrastructure inspection, 2026.09 - 2027.09. (expected)

• Postdoctoral and other researchers:

1. Jianfeng Guo, Rail vehicle dynamics under adverse conditions, 2023.12 - 2024.12. (finished)
2. Sidharth Kapoor, Energy modelling and calculation of rail transport system, 2022.09 - . (ongoing)
3. Emma Bergeot, Developing methodology for climate-related risk assessment for rail transport system, 2025.01 - 2025.06. (finished)

Award and prize

• IMechE’s “T A Stewart-Dyer Prize/ Frederick Harvey Trevithick 2025 Prize”, by the paper entitled “Application of smart wayside object controller to railway signalling system for decarbonisation” *(First author, partner organization: Trafikverket and Alstom).

• The 3rd international conference on rail transport, 2024, “Best Paper Award for Students”, by the paper entitled “An extended quasi-static method for adjusting contact wire pre-sag to special operational conditions”,*(Second author, student supervisor).

• Ministry of Railways of China, 2011, “Commemorative Medal for Builders of the Beijing-Shanghai High-Speed ​​Railway”, for the contribution to the construction and commissing tests of Beijing-Shanghai High-Speed Railways.