Dynamic DC link Voltage Control Strategy of Electric Vehicles Considering the Cross Saturation Effect.

Abstract

The interior permanent magnet synchronous machine (IPMSM), which could generates reluctance torque in flux weakening region to enhance the motor performance and efficiency, is widely applied in electric vehicles (EV) [1, 2]. In order to dig out the maximum potential of the traction system of EV further, dynamic DC link voltage control strategies has been explored by several researchers [3, 4]. Generally speaking, keeping a low DC link voltage at low operating speed could reduce the switching losses of the inverter while boosting its value at high speed could benefit the flux weakening operation [5] However, the IPMSM parameters will become different with operating conditions, for example, the inductance and the magnetic characteristic will change with current due to the cross coupling and magnetic saturation effect (omitted to cross saturation effect) [6]. Therefore, the conventional control strategy of IPMSM ignoring the cross saturation effect needs to be revised.