PMSM Drive with Sliding Mode Direct Torque Control

The paper deals with utilization of sliding mode theory in speed control of direct torque controlled permanent magnet synchronous motor drive. In order to smooth stator current waveform, pulse-width-modulation (PWM) technique are selected, and space vector PWM is employed to receive high motor torque. Conventional proportional-integral (PI) speed controller does not guarantee high performance in both dynamic and steady-state operations, especially at times of load variation. Sliding mode control is chosen to enhance the performance of drive system. Simulations for both systems with conventional PI speed controller and sliding-mode-based speed controller are constructed. Integral performance indices including integral of time multiplied by the absolute value of speed error (ITAE), integral of time multiplied by the square of speed error (ITSE), integral of the absolute value of speed error (IAE), integral of the square of the speed error (ISE), are used to evaluate performance. Results confirm the expected performance of drive system with sliding-mode-based speed controller.