Optimized Dynamic Wireless Power Transfer for Moving Electric Vehicles With Constant Output Voltage

ABSTRACT To address the issue of output power fluctuation during dynamic wireless charging, this paper presents an optimized dynamic wireless power transfer (DWPT) system transmitting end for electric vehicles (EVs). The system realizes a load‐independent constant‐voltage output by selecting a multitransmitter LCC‐S network topology. This paper gives an analysis of a dual‐transmitter LCC‐S network considering cross‐coupling, as well as a multitransmitter LCC‐S network eliminating cross‐coupling. The conclusions are generalizable. This paper develops a generalized analytical model for the mutual inductance of rectangular coils. By partially overlapping the transmitter coils, the cross‐coupling is eliminated, and an optimized design of the transmitter coils system is achieved. The optimization parameter is applicable to any conventional rectangular transmitter coils system. The system is designed to be simple and easy to apply, achieving automatic current distribution on the inverter side without control modules. A 2‐kW DWPT prototype, using 85‐kHz operation frequency, is constructed according to the designed magnetic coupler and circuit parameters. The experimental results show that the system can maintain a high average efficiency (80%) and 1.89kW average DC output power in the dynamic charging process. The changes in the load do not affect the output voltage. The transmitting end of the DWPT system can provide a constant‐voltage output with only ±3% fluctuation, the output power fluctuates less than ±6% from the average, and the transmission efficiency fluctuates less than ±2% from the average.