A Multifunctional Bidirectional Motor Drive System for EVs: Three‐Phase Charging, V2G, V2V and Traction Modes

ABSTRACT

Using separate power converters for charging, vehicle‐to‐grid (V2G), vehicle‐to‐vehicle (V2V) and traction instead of an all‐in‐one power converter creates trade‐offs in convenience, cost and reliability. This paper proposes a multifunctional, bidirectional motor drive system for electric vehicles (EVs). The proposed approach utilises a three‐phase parallel winding machine drive system to support four operating modes: three‐phase AC charging, V2G, V2V and three‐phase motoring. The charging/V2G circuit is realised by connecting a three‐phase AC source to the motor winding terminals while leaving the motor's neutral point open. For V2V mode, the circuit is established by connecting the DC buses (positive and negative bus bars) of the receiving EV to the transmitting EV's motor winding terminals and the converter's negative line. In these non‐driving modes, the issues of electromagnetic torque and harmonic current production are addressed through the stator winding rearrangement technique and ripple current controllers, respectively. As a result, the system operates with zero torque production and a unity power factor (UPF), while maintaining a total harmonic distortion (THD) of current below 5%. Moreover, the efficiency under these four modes is evaluated. The system topology and control algorithms are presented in detail. And experimental results are provided to verify theoretical analysis.