考虑小电感区电感变化量的开关磁阻电机开关角优化方法

Switch angle optimization method for switched reluctance motor considering the inductance variation in small inductance period

开关磁阻电机(switched reluctance motor,SRM)电磁特性具有高度非线性的特点,采用传统的开关角优化方法很难取得理想的控制效果。以三相12/8极SRM为研究对象,采用有限元方法计算了样机的电磁特性,分析了小电感区的非线性特点,建立了电机小电感区内的非线性数学模型,推导了最优开通角的解析式,根据开通角解析式与电机运行时的磁链变化规律,得出了最优关断角解析式,实现了不同转速下开通角与关断角的自适应调节。实验结果表明:改进的开关角优化方法简单有效,提高了系统运行效率和带载能力。

It is hard to get good performance by using the traditional method to optimize turn-on and turn-off angles because of the high nonlinearity of switched reluctance machine(SRM).The prototype is a three-phase,12/8-pole SRM.The electromagnetic characteristics of the prototype were obtained by finite element method and the feature in low-inductance period was discussed.The non-linear model of inductance in the low-inductance region was established and the analytical formula of optimal turn-on angle was deduced.The analytical formula of optimal turn-off angle was also deduced according to the turn-on angle and the flux-linkage variation law when prototype operated.The adaptive adjustment of switch angle at different speeds was achieved.The experimental results show that the optimization methods of turn-on and turn-off angle are simple,which can improve the efficiency and load capacity.