Research on new sensorless control strategy of surface mounted PMSM

摘要

In order to accurately estimate the speed and position during the speed regulation of surface mounted permanent magnet synchronous motor, a new sensorless control strategy is proposed for model reference adaptive technology. Firstly, a new type of non-singular fast terminal sliding mode technique is introduced to optimize the robustness of the model reference adaptive observer. Secondly, in order to eliminate the error of speed estimation during motor startup and varying load disturbance, low pass filter is introduced into the combination of model reference adaptive and sliding mode variable structure. Finally, a hyperbolic tangent function is used to replace the traditional switching function to weaken the chattering effect of the sliding mode variable structure on the system. The simulation results show that using the new sensorless control strategy, the error of the speed estimation can be controlled within 0.3r/min. In addition, there is no phase lag and it can hold errors to a minimum during the rotor position estimation. Compared with the traditional model reference adaptive, the system can still estimate the speed accurately when the system is started and the speed is changing.