Interoperability Improvement for Wireless Electric Vehicle Charging System Using Adaptive Phase-Control Transmitter

Poor interoperability between the rectangular coil and DD coil leads to significant decline in transmission power and efficiency. This paper proposes an adaptive phase-control transmitter (APCT) which is interoperable with different receiving coils for wireless electric vehicle charging (WEVC). First, an optimized bipolar (BP) coil is designed and APCT is capable of generating different flux distributions for different receiving coils. Second, inverter output currents' detection is used to identify the type of receiving coils. Third, mutual inductance is estimated using the primary-side electrical information. Finally, constant current (CC) charging, as well as efficiency optimization method, is introduced. With an X offset and a Y offset of 50 mm, an experimental setup achieves 3-A CC charging for both rectangular and DD receiving coils. The experimental results agree with the theoretical analysis, demonstrating that the proposed APCT is able to improve interoperability with different types of receiving coils.