Low Speed Sensorless Vector Control Of Surface Mounted Permanent Magnet Synchronous Motor Based On Pulsating High-frequency Current Injection

Permanent Magnet Synchronous Motor (PMSM) has been widely used in fields such asaerospace, medical equipments, instruments and computer numerical control (CNC) machines for itsadvantages of small size, high efficiency, power density, etc. However, the defects due to theinstallation of mechanical position sensors used to obtain the rotor position and speed signals limit thesystems’ application areas. Therefore, the sensorless control technology emerged and is being theindustrial and academic research focus. In order to estimate Surface Mounted Permanent MagnetSynchronous Motor (SPMSM) rotor position under low and zero speed without a position sensor, thepulsating high-frequency current injection method is presented in this paper,.First of all, the state of the art review of PMSM system and sensorless control technology hasbeen given based on the domestic and foreign literatures. A brief classified list of the sensorlesscontrol methods has been proposed.Secondly, the PMSM vector control system model with position sensor is constructed usingMATLAB/Simulink and static and dynamic performance analysis is carried out.Then, after studying the traditional high-frequency signal injection methods, mainly the rotatinghigh-frequency voltage/current injection and the pulsating high-frequency voltage injection method,the principle of magnetic saturated saliency of SPMSM is analyzed. The theoretical derivation andstructural design of the rotor position estimation of proposed pulsating high-frequency currentinjection method are given, verifying the feasibility and effectiveness of the method throughsimulation. The preliminary comparison of the stator resistance effects on the pulsating highfrequency voltage injection method and the pulsating high-frequency current injection method isinvestigated, drawing the conclusions that the latter is more stable.Finally, a hardware platform based on TMS320F2812with a1.5kW SPMSM is designed andconstructed, with which the feasibility of low-speed position sensorless control scheme based on theproposed method is verified by experiments.