Permanent Magnet Synchronous Motor Control System with Filterless High Frequency Square Wave Injection

To address the problems of limiting system bandwidth., reducing dynamic performance., and phase lag caused by the use of filters in the high-frequency injection method of permanent magnet synchronous motors under low-speed operating conditions., a filterless control method for high-frequency square-wave voltage injection is proposed. Firstly., a high-frequency square-wave voltage signal is injected into the d-axis observed rotor shaft., and the rotor position error is calculated by the filterless high-frequency response signal separation method. Then., the rotor position is observed by a modified Lomborg state observer with higher observation accuracy. Finally., the proposed filterless high-frequency square-wave voltage injection control strategy is simulated and experimentally verified using a IPMSM position sensorless vector control platform., both of which show that the improved control method reduces the rotor position estimation error., increases the accuracy of position estimation., and improves the system identification accuracy.