Research on Decoupling Control Strategy for Interior Permanent Magnet Synchronous Motor in Flux-Weakening Region

Interior permanent magnet synchronous motors can be applied to applications requiring wide-speed operation by means of flux-weakening control. While due to the fixed capacity of PWM inverter, the high speed operation range of interior permanent magnet synchronous motor (IPMSM) is mainly limited by the saturation of current regulator. In constant power region, in stead of the available voltage that controls the armature current vector, the current vector sometimes becomes uncontrollable in transient operations because of the current regulator saturation. In order to extend its operation range, the current vector control algorithm of IPM motor over the base speed operation is proposed in this paper which includes the decoupling current control and the voltage command compensation. Also this paper introduces a judgment method to monitor if the current regulator has gone into saturation or not. Finally on the basis of simulation results, the effectiveness of this control strategy is further confirmed by real drive tests.