An electric vehicle integrated battery charger with high utilization rate of the three‐phase open‐winding permanent‐magnet‐synchronous‐motor

Abstract

AbstractThis paper proposes an integrated battery charger for electrical vehicles (EVs) employing a three‐phase open‐winding permanent magnet synchronous motor (3p OW‐PMSM), which can be simply modified from a typical star‐connected PMSM. It reutilizes the existing propulsion components to achieve fast charging and vehicle to grid (V2G) operations. Only one nonintegrated inductor is added to realize torque cancelation so that no rotation or vibration is generated. In the fast‐charging and the V2G modes, the current flowing through the inductor is half of one phase grid current, namely, one in six of the total grid currents. The rest five in six of the grid currents flow through the stator windings of the motor. Hence, the proposed integrated system has a high utilization rate of the motor and possesses high power density. In addition, an individual inner current controller for each leg of the AC‐DC converter is employed to ensure the unity power factor, low current harmonics, and torque elimination. In the motor‐drive mode, the equivalent circuit is consistent with the conventional 3p star‐connected motor driver. Therefore, it does not increase the complexity of the motor‐drive control strategy. Finally, simulation and experimental results for fast‐charging, V2G, and propulsion operations verify the feasibility of the proposed scheme.