Enhancing V2G Applications: Analysis and Optimization of a CC/CV Bidirectional IPT System With Wide Range ZVS

Bidirectional inductive power transfer (IPT) systems could enhance the flexibility of energy interaction between electric vehicles (EVs) and the grid, as well as other electrical equipment. Achieving zero-voltage switching (ZVS) conditions is a critical factor in improving the efficiency of bidirectional IPT systems. This article proposed a double-sided LCC compensation parameter design method, particularly suited for vehicle-to-grid (V2G) applications, which realizes the constant current (CC) output during the charging process and the constant voltage (CV) output during the discharge process of the bidirectional IPT system. A detailed analysis of parameter tuning methods is provided, with the aim of achieving CC/CV output and wide ZVS operation during charging and discharging processes. The inverter turn-off current is accurately estimated, considering the impacts of higher harmonics and the reflected reactance of the rectifier, to optimize the system's compensation parameters. The effectiveness of the proposed method is verified by a 10-kW bidirectional IPT prototype, and the CC/CV feature and wide ZVS range are achieved. The experimental results demonstrate that the peak efficiency reaches 96.6% when transmitting power as a current source during charging, and 96.2% when transmitting power as a voltage source during discharging.