A Dynamic Compensation Method for Time Delay Effects of High-Speed PMSM Sensorless Digital Drive System

The PWM update is inevitably delayed one sampling period due to the time-consuming calculation of the digital processor, the delay time products a severe phase and amplitude error in output voltage when the PMSM is running at high speed and the carried ratio is insufficient, affecting the stability of the high-speed PMSM sensor-less drive system. Against its defects, a dynamic compensation strategy is implemented in this paper, it compensates for the phase and amplitude error with the PI regulator constructed by the difference of the d-q axis voltage between the delayed state and the ideal state. Compared with the traditional method, this dynamic strategy has a simpler calculation and greatly improves the stability of the high-speed PMSM sensor-less drive system. Finally, the compensation method proposed in this paper is successfully verified by the experiment results.