开关磁阻电动机互感特性及其对转矩的影响

Mutual inductance of switched reluctance motor and its effect on torque

开关磁阻电动机在两相励磁的工作条件下,定转子轭部磁场高度饱和使每相磁链有所减小。通过引入互感的方法可以定量计算磁链的减小量,并给出了互感计算式,利用有限元法分析了一台样机互感随转子位置和电流的变化规律,理论推导了互感对平均转矩影响的程度,研究了四相8/6极开关磁阻电动机稳态转矩波形在两种绕组连接方式下的不规则特性,结合互感特性,提出了改变不对称相绕组参数的技术方案。研究结果表明:电磁参数优化后,开关磁阻电动机的最小转矩和平均转矩均得以提高,转矩脉动减小,转矩波形规则。

When the switched reluctance motors operate in two phase excitation mode, the phase flux linkage will be reduced due to the high magnetic saturation in the stator and the rotor yoke. The reduction can be quantitatively calculated through mutual inductance. The computation expression of mutual inductance was proposed. The variation of mutual inductance with regard to rotor position and phase current was analyzed by finite element analysis for a prototype motor. The influence of mutual inductance on average torque was theoretically derived. The torque waveforms in steady state were simulated in two types of winding connections, which are irregular in the 8/6 four phase switched reluctance motor. Based on the mutual inductance, a technical scheme to change the parameters of asymmetrical phase windings was proposed. The simulation results show that the minimum torque and average torque are both increased, torque ripple is reduced and the torque waveform becomes regular.