An Improved High Frequency Square Wave Injection Permanent Magnet Synchronous Motor sensorless Control

In the sensorless control of high-frequency signal injection permanent magnet synchronous motor, rotor position information can be obtained from high frequency response current, So extracting high frequency current is a crucial part. Aiming at the shortcomings of traditional methods of extracting high-frequency currents such as large errors and delays, an improved method is proposed to introduce the equal ripple Chebyshev best approximation finite impulse response filter into the signal extraction. The benefits of this filter include linear phase and maximum error minimization of passband and stopband. High-frequency current can be extracted effectively, the extraction error is minimized, and the interference of harmonic current generated by the inverter is also suppressed. In this paper, a high-frequency square wave is injected into a permanent magnet synchronous motor, and the simulation results showed the effectiveness and superiority of the proposed method.