内置式永磁同步电机动态偏心故障下的轴电压解析分析和削弱

Analysis and Reduction of Shaft Voltage in Interior Permanent Magnet Synchronous Motors under Dynamic Eccentricity Fault

对于变频器驱动的内置式永磁同步电机,大多数研究集中于变频器共模电压对轴承电压的影响,忽略了磁路不平衡导致的轴电压。针对内置式永磁同步电机动态偏心故障下的轴电压,首先,运用解析法推导轴电压的表达式,分析轴电压的特征频率;其次,研究改变转子磁极的极弧系数削弱偏心轴电压的方法;最后,建立4极6槽、2极9槽、4极9槽、8极9槽在内的4台内置式永磁同步电机偏心轴电压模型,进行有限元验证。仿真结果表明,通过削弱固有轴电压分量可以削弱偏心轴电压,40%偏心度下4台电机削弱效果分别为59.05%、26.90%、43.31%、22.60%。

For interior permanent magnet synchronous motors driven by inverters,most studies focus on the effect of the common mode voltage on the bearing voltage,ignoring the shaft voltage caused by asymmetric magnetic fields.Regarding the shaft voltage under dynamic eccentricity fault,the expression is deduced by the analytical method,and the characteristic frequency is analyzed.Then,the method of reducing the eccentric shaft voltage is studied by changing the pole-arc coefficient of rotor poles.Finally,four eccentric shaft voltage models with different pole-slot combinations including 4 p6 s,2 p9 s,4 p9 s and 8 p9 s are established.The effectiveness of analytical analysis is verified by the finite element method.The simulation results show that the eccentric shaft voltage can be weakened by reducing the inherent shaft voltage.And the eccentric shaft voltage at 40%eccentric degree is reduced by 59.05%,26.90%,43.31%,22.60%,respectively.