An Improved High Frequency Sine Wave Injection Permanent Magnet Synchronous Motor Sensorless Control

In the traditional high-frequency sine wave injection method, the use of many filters results in reduced accuracy of detection. Therefore, it is of great significance to simplify the filtering design and improve the accuracy of detection. Firstly, the band-pass filter extracting the high-frequency current with rotor information in the traditional method leads to phase lag. The phase-frequency characteristics of the band-pass filter is analyzed, and a modulation signal considering phase compensation is used to eliminate phase lag. Secondly, fundamental frequency currents are obtained by the difference between d and q axis currents and d and q axis high frequency response currents so that the two low-pass filters used to extract fundamental frequency currents are eliminated. Finally, to obtain a more accurate rotor position error signal, a second-order generalized integrator with better phase-frequency characteristics is used to replace the low-pass filter to extract the rotor position error signal. The simulation results claim that the improved way is better.