AUTHOR=He Rui , Gao Jian , Yang Aixi , Zhou Jing 

TITLE=Design and Optimization of a Modular Wireless Charging Scheme for Electric Buses With High Misalignment Tolerance

JOURNAL=Frontiers in Energy Research

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2022.858737

DOI=10.3389/fenrg.2022.858737

ISSN=2296-598X

ABSTRACT=Modular design helps to improve the reliability and power density of power electronic systems, so cascading of power electronics modules is an effective method to improve the overall stability of the system. The application of wireless power transfer (WPT) system to electric bus faces the challenge of higher power requirement, modularization provides a solution to the design of wireless charging system for electric buses. A modular wireless charging system for electric bus is proposed in this paper, the system consists of five identical 6.6kW wireless charging modules distributed relatively disperse on the chassis. Through the design of coils layout, different modules on the receiver side can be decoupled from each other, which facilitates independent control. Each module utilizes the bipolar-solenoid coupling structure, which proves to have high misalignment tolerance. In order to reduce the electromagnetic radiation for passengers on the electric bus, shielding is added on the receiver side. Five independent modules work collaboratively to compose a 30kW wireless charging system for electric buses. The DC-DC efficiency is 87.44% in aligned position at 200mm transmission distance. With closed-loop control, the proposed system has high misalignment tolerance in the horizontal X-Y plane. Compared with open loop control scheme, the average efficiency of the proposed system increases by 22.1% within 300mm misalignment.