Mutual inductance identification and maximum efficiency control of wireless power transfer system for the modern tram

Abstract

Wireless power transfer (WPT) technology has been considered as a promising power supply method for modern trams with electric double layer capacitors (EDLC). However, in real case, factors such as parking misalignments, load variations and coils inclination would result in a deviation of coils mutual inductance, which may adversely impact on system transmitting efficiency. Therefore, an approximately real-time identification method of mutual inductance is proposed in this paper to help achieve the current maximum efficiency in a non-ideal system. Moreover, the Discrete Fourier Transform (DFT) algorithm is used to reduce sensor noise and eliminate harmonics. Simulation and experiment results verify the accuracy of the method of mutual inductance identification.