A Rotor Position/Speed Identification Method of Permanent Magnet Synchronous Motor for Low Speed Operating Condition and Parameter Perturbation ⋆

Accurate positioning of the motor requires high control performance for low-speed operation and motor’s parameter perturbation. In the AC motor vector control technology, the nonsingular higher-order terminal sliding mode observer of Insertion Permanent Magnet Synchronous Motor (IPMSM) is put forward based on the object current and voltage values to obtain the rotor position and speed signa. The accurate and reliable identification of the motor rotor position and speed is realized to provide the necessary information of rotor position and speed for high performance vector control system. In order to improve the dynamic response of the observer and overcome the parameter perturbation, the nonsingular terminal sliding mode control is used in the present study. Compared with the general sliding mode control, the chattering phenomenon is reduced by using the high-order sliding mode control technology features. The algorithm is applied to the theodolite micro shafting control system with sensorless IPMSM, which paves the way for theodolite precise target localization. The experiment results show that the method can accurately identify the motor rotor position and speed with strong robustness, good steady precision and dynamic performance.