无轴承开关磁阻电机磁饱和特性的电磁场分析

Electromagnetic Field Analysis of Magnetic Saturation Characteristics of Bearingless Switched Reluctance Motor

阐述了无轴承开关磁阻电机径向悬浮力产生的原理,考虑电机内复杂的磁场饱和情况,定性分析了主、副绕组电流大小对悬浮力的影响。计及磁场饱和,建立了无轴承开关磁阻电机的有限元分析模型,以一台3kW样机为例计算了各种主、副绕组电流组合时的转矩与悬浮力。数值计算结果验证了定性分析所得结果,表明无轴承开关磁阻电机在运行中存在比传统开关磁阻电机更加复杂的磁饱和现象,磁饱和使得电机悬浮力与绕组电流关系严重非线性,而且悬浮力大小并非总是随绕组电流的增加而增加,存在随电流增加悬浮力减小的情况,这必然给稳定悬浮控制带来困难。

This paper describes the principle of radial force in bearingless switched reluctance motor. In consideration of the complex magnetic saturation characteristics in the motor, the influence of the main and auxiliary winding currents on the suspension force. In view of saturation of field saturation, the model of finite element analysis for the bearingless switched reluctance motor is established. Taking a 3kW prototype as the example, the torque and suspension force with the combination of various main and auxiliary winding currents are calculated. Through value calculation, the result by qualitative analysis is verified, and it shows that there is more complex magnetic saturation phenomenon in the bearingless switched reluctance motor than in the traditional switched reluctance motor, the serious nonlinearity of the relationship of the suspension force and winding currents is caused by the electromagnetic saturation, and the suspension force does not always increase with the increasing winding currents, and decreases with it, so that it is difficult to control the suspension force.