永磁无刷直流电机换相转矩波动的分析研究

Analysis of the Commutation Torque Ripple of Permanent Magnet Brushless DC Motors

在考虑齿槽、永磁体结构的影响时,根据相绕组的实际感生电势,讨论了永磁无刷直流电机的换相过程.从一个新的角度分析了绕组换相引起转矩波动的原因,指出换相转矩波动不仅与电机绕组电流有关,还与换相时相绕组感生电势瞬时值、换相位置角、绕组参数等因素有关.通过数值计算结果说明了各因素对换相转矩波动的影响程度,为研究换相转矩波动的减小措施和永磁无刷电机的设计及控制提供了理论依据.

According to the actual phase electro-motive forces (EMF's), the commutation of the brushless DC motor is investigated, considering the effect of slotting and the structure of the permanent magnet. From a new point of view, the causes of the torque ripple induced by the commutation are analyzed. It is showed that the torque ripple is not only connected with the phase currents, but also with the other factors, such as the instantaneous phase EMF's in the case of commutation, the angle of commutation and the parameters of the windings. The effect of each referred factor on the commutation torque ripple is calculated by the numerical computation so that the foundation is theoretically established for further research for reduction of commutation torque ripple, the design and control of the brushless DC motors.