Research on Control Strategy of Permanent Magnet Synchronous Motor Based on Fast Terminal Super-Twisting Sliding Mode Observer

The sliding mode observer (SMO) has the advantages of small influence by parameter changes and strong robustness, which is widely used in the sensorless control of permanent magnet synchronous motor (PMSM). However, when the sliding mode observer is used to observe the position and speed information of the PMSM, the problem of slow response and excessive chattering is always accompanied. In order to reduce the time of observation position and improve the anti-interference of the system, the super-twisting sliding mode observer(STSMO) is proposed, which can be used to reduce the chattering amplitude effectively, Additionally, the fast and terminal factors is added to the sliding mode surface so that it can converge quickly in a finite time. Then, an improved fast terminal super-twisting sliding mode observer (FTSTSMO) is proposed in the extended state. It can be proved that the observer can converge by Lyapunov stability, and the new observer can suppress chattering and improve the convergence speed. Finally, the experimental analysis is carried out on the 1kW permanent magnet synchronous motor experimental platform, and the SMO and STSMO are compared with FTSTSMO. The results show that FTSTSMO can effectively reduce the fluctuation of the system, improve the tracking effect of rotor speed and rotor position when the speed changes, and further make the whole control system of PMSM have stronger robustness and stability.