Analysis and Design of Current Regulators for PMSM Drives Based on DRGA

The current-control loop plays an important role in achieving the rapid torque response of the vector-controlled salient pole permanent magnet synchronous motor (PMSM). Since the cross coupling of the motor model can deteriorate the performance of the current-control loop, numerous decoupling current regulators have been reported. However, less attention is drawn to the theoretical evaluation of the decoupling performance of the current regulators. In this article, the dynamic relative gain array (DRGA) is adopted to compare the performance of different decoupling current regulators and further used to design a current regulator with better decoupling performance. With the two-degree-of-freedom (2DOF) regulator seen as a general structure of decoupling current regulators, a design process of the 2DOF regulator is developed based on the DRGA. Finally, an optimal structure of the 2DOF regulator is proposed. The results of simulation and experiment on a 3-kW PMSM platform are provided to support the theoretical analysis and demonstrate the better decoupling performance of the 2DOF regulator with the proposed structure.