电动汽车用SRM励磁方式的研究

Research on Exciting SRM for Electric Vehicles

开关磁阻电机(Switched Reluctance Motor,简称SRM)适用于电动汽车交流驱动,但其转矩脉动会降低汽车的运行质量。为降低SRM的转矩脉动,将三相SRM绕组采用星型连接,用三相逆变桥对其驱动。当采用传统的控制方式时,电机运行状况不佳。根据SRM产生电磁转矩的原理,分析了自感和两相互感在电机运行中产生电磁转矩的情况,并根据其变化规律,推导出独特的720°电角度一周期的对称不均匀两相励磁方式,使磁阻电机获得了良好的运行效果。实验证明,相较于常用的单相励磁方式,该励磁方式可有效改善SRM的转矩脉动和噪声。

The switched reluctance motor （SRM） suits to drive electric vehicles,but it＇s torque ripple can worsen the quality of electric vehicles.In order to reduce torque ripple of SRM,a star type connection was adopted on a three phase SRM,which is supplied with a three phase inverter bridge.Using traditional control methods could not get good effect.According to the principle of SRM＇s electromagnetic torque,self-inductance and mutual-inductance＇s effect on electromagnetic torque were analyzed.With the rule of their variation,the special symmetry and uneven two phase excitation mode with 720° electric angle a cycle were used, and got good result.The experimental results show that comparing with the conventional single phase excitation mode on SRM,this novel excitation scheme can reduce the torque ripple and noise.