Research on the application of tracking differentiator in permanent magnet synchronous motor controlling system

摘要

Because of high switching frequency, the output voltage of inverter includes high frequency noise, when the voltage space vector PWM technology is adopted to control the speed of permanent magnet synchronous motor (PMSM). It makes the stator current of motor also include high frequency noise. The signal which includes high frequency noise needed to be processed by the differentiator in the speed and current double closed loop control system. But the classical differentiator can amplify the noise. Because of that the useful differential signal will be sub-merged in amplified noise. That just can make us use PI controller. So the tracking differentiator is designed. This tracking differentiator can suppress the amplification effect. The tracking differentiator is applied to PID controller which combined with the speed and current double closed loop control system based on voltage space vector PWM control technology, and achieved the quickly and accurately automatic control for the motor rotational speed.