Research on the robust current control algorithm of permanent magnet synchronous motor based on deadbeat control principle

The current loop performance is limited due to the inherent sampling and filtering delay of numerical control system. In order to further improve the current control performance of servo system, this paper presented a robust predictive current control for permanent magnet synchronous motors (PMSM) based on deadbeat control to improve the performance of the current loop. According to the current reference and the feedbacks of relevant state variables, the proposed algorithm calculated the switch signals applied in the next sampling period. The reduction of system phase margin which is caused by current sampling and filtering and the motor inductance error were analyzed. In order to compensate the phase margin and increase the tolerance of inductance error, the Luenberger state observer was involved. The system phase margin will be increased by means of adjusting the robust parameter. The relationship of robust parameter between the system bandwidth and phase margin were given. A 750 W PMSM was involved to verify the effectiveness of the proposed algorithm, and then the simulation and experiment results are analyzed.