考虑死区效应影响的永磁同步电机磁链估计

摘要

研究了永磁同步电机在无位置传感器运行下的永磁体磁链估计.采用反电势积分法来对转子位置进行估计,该方法不需要磁链信息,因此可以保证磁链估计和位置估计的解耦.在此基础上,利用估计的转子位置获得q轴的电压电流并用于估计永磁体磁链.逆变器的死区效应会造成磁链估计误差,对其影响进行了理论分析,得到逆变器输出电压误差均值恒定的结论,并提出了一种利用差分法消除死区影响的方法.最后,通过试验验证了该磁链估计方法的有效性.%A method of estimating magnet flux of permanent magnetic synchronous motor under sensorless control was proposed.The back electromotive force integration based algorithm was adopted to acquire rotor position.The information of magnet flux was not necessary for this algorithm,thus the decoupling of magnet flux estimation and rotor position estimation could be guaranteed.On this basis,the q-axis voltage and current were used to estimate magnet flux.The dead-zone effect of the inverter raised estimation error of magnet flux,which was theoretically analyzed,coming to the conclusion that the average error of inverter output voltage was constant.A difference method was then proposed to eliminate the influence of dead-zone effect.At last,the validity of this magnet flux estimation method was verified by experiments.