Anti-Resonant Tank-based Wireless Charging of EVs for Ultra-Wide Output Voltage Applications

Wireless chargers are becoming increasingly popular for charging electric vehicles (EVs) due to their autonomous potential, safety, and convenience. For the fast adoption of EVs, a wireless charger installed at public parking spaces should be compatible with different types of EVs (2-wheeler, 3-wheeler and, 4-wheeler) and support various battery voltages within the operating frequency range of 79–90 kHz. Conventional wireless chargers employ a three-stage topology to achieve a wide output voltage range, typically incorporating a buck-boost converter at the charger or battery side, which increases the system's cost. This paper proposes a single-stage topology utilizing series-series compensation with an LC anti-resonant tank-based wireless charging system for EVs, achieving an ultra-wide output voltage range from 150–900 V. The LC anti-resonant tank provides the ultra-wide output voltage range by nullifying the voltage gain at the anti-resonant frequency. Furthermore, the incorporation of an LC tank and frequency modulation control technique enables a wide zero voltage switching area throughout the voltage range, which reduces switching losses in the converter. The analysis and design of the proposed system have been conducted and verified through MATLAB simulation for the output voltage range of 150–900 V. Finally, a 3-kW prototype is developed to transfer power over a 15 cm air gap, achieving maximum efficiency of 90% in simulation and 87% in hardware.