RESEARCH OF TORQUE CONTROLLER WITH VARIABLE PROPORTION IN PERMANENT MAGNET SYNCHRONOUS MOTOR DRIVE

In this paper, a proportional-plus-integral (PI) torque controller with variable proportion for direct torque control (DTC) of permanent magnet synchronous motor (PMSM) drive based on the torque angle control is proposed. By analyzing the torque control of PMSM, the optimum design of proportion in the PI torque controller is presented in order to reduce the torque error in dynamic state resulted from the nonlinear relationship between the torque and torque angle, and ensure exact and quick control of torque in dynamic state. In order to eliminate the steady-state error of torque and guarantee the stability of system, the design of the integral part of PI torque controller is deduced by using the small signal model of system. The experimental results verify the feasibility and effectiveness of the proposed PI torque controller.