A switched-capacitor step-up inverter for bidirectional wireless charging applications in electric microcar

Wireless power transfer (WPT) offers a more convenient and safer option for electric vehicle (EV) charging. However, the mismatch of the DC link voltages between the charging stations and small scale EVs may increase the difficulty of design and control of the charging facilities. Along with the growing penetration of renewable energy, vehicle-to-buildings (V2B) and vehicle-to-grid (V2G) interfaces, requiring bidirectional power flow would be the essential features of future EV wireless charging systems. In order to tackle this issue, this paper suggests a high-frequency step-up inverter based on series-parallel conversion of switched-capacitor with the associated staircase modulation and power flow control for WPT applications. Corresponding to the system parameters of a typical electric microcars, the operating principle and the power flow control of the proposed inverter are verified by simulation. The battery power as well as the primary and secondary AC waveforms of the simulation model are presented.