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Liu, Bochen

Liu, Bochen

PROJECT TITLE: A universal and optimized robust EV charger

PhD period: 2017.11.01 – 2020.10.31.
Section: Power Electronic Systems
Research Programmes: Efficient and Reliable Power Electronics and E-Mobility and Industrial Drives
Supervisor: Frede Blaabjerg
Co-Supervisor: Pooya Davari
Contact Information

Collaborator: Chinese Scholarship Council. 
Funding: China Scholarship Council.


Currently, limited full-electric mileage and unsatisfactory charging time are the two main barriers in fast deployment of electric vehicles (EVs). In order to overcome the mileage limits, significant work and development have been devoted on improving the battery performance. Taking the newly released Tesla Semi truck as an example, the capacity of the battery pack is estimated around 1MWh which can be seen as a breakthrough of energy level. However, a larger battery capacity also means a longer charging time. Consequently, high power EV chargers are needed to balance these two parameters to achieve the goals of fast on-board charging and ultra-fast off-board charging.  

Usually, the higher power rating of a converter, the larger size it takes for the power components to undertake the voltage or current stress. Increasing the power density is therefore necessary for the power converters, especially for the on-board chargers. Nevertheless, the thermal density is also increased, which may deteriorate the lifecycle of the charger. For this reason, the reliability should also be accounted in the design phase.

The aim of this PhD project is to design a universal and optimized robust charger for EVs, including the following aspects: 1) Modular and universal design to achieve fast charging; 2) Developing a compact structure for the power converter; 3) Design for reliability to cope with the thermal stress issue. Finally, electrical-thermal analysis and simulation will be performed and a laboratory prototype will be built to validate the theoretical analysis.


Publications in journals and conference papers may be found at VBN.