基于定子磁势闭环控制的无刷直流电机空间矢量无位置传感器起动新方法

New Sensorless Starting Method of BLDCM Based on SVPWM and Stator Magnetomotive Force Control

针对无位置传感器的永磁无刷直流电机开环起动转矩脉动大、起动成功率低的问题,分析了基于三三导通三相逆变器的电压空间矢量调制(Space vector pulse width modulation,SVPWM)控制,并推导了三相星形连接下的定子合成磁势矢量与电流最大相磁势矢量的关系。在此基础上,提出了一种在前级增加定子磁势调节的起动控制策略并对其进行简化。该起动算法不依赖于电机转子凸极性和初始位置,并有效控制了起动电流大小和抑制了起动转矩脉动,电机开环起动性能比传统的升频起动显著提高。最后通过仿真和实验验证了该起动控制算法的有效性。

In open-loop starting process of brushless DC motor（BLDCM） without position sensors, pul sations of torque and speed are large and motor cannot even start successfully. To solve those problems, space vector pulse width modulation （SVPWM） control schema of three-phase inverter employing 180° switch-on mode is analyzed and applied to BLDCM. Moreover, relationship between the composed stator magnetomotive force and current maximum phase＇s magnetomotive force is derived with windings in Y connection. Hence, a new starting control method combing stator magnetomotive force regulation with SVPWM is proposed. Furthermore, calculation of the composed stator magnetomotive force is simpli- fied. The proposed starting method is independent on saliency or initial position of rotor. It can also ef- fectively suppress ripples of speed and torque, so its starting performance is greatly improved compared with conventional variable-frequency open-loop start. Finally, validity of the presented method is veri- fied by simulation and experiment.