考虑交叉饱和影响的永磁同步电机稳态参数有限元分析

Finite Element Analysis of PMSM Steady State Parameters Considering Cross-saturation Effect

针对永磁电机相关控制策略及性能计算均需要准确地得到电感和磁链等稳态参数,而它们又受交叉饱和效应影响严重,常规方法无法准确计算的问题,以有限元为工具,分析了计算永磁磁链和直轴、交轴电枢反应电感的不同方法。研究了交叉饱和效应对永磁电机的直轴、交轴电枢反应电感的影响,提出由于交叉饱和效应导致的直轴交轴存在互感,以及直轴上的永磁磁势产生交轴磁通的问题。采用冻结单元磁导率的方法,将非线性场线性化,计算得到了稳态参数随直轴、交轴电流变化的趋势。通过对比,使用计算得到的稳态参数仿真结果和实际测试结果,在空载与负载条件下的吻合很好,证明了使用冻结磁导率法计算参数是可靠的。

Accurate permanent magnet synchronous motor（PMSM） steady-state parameters such as armature reactance inductance and permanent magnet flux are essentially necessary for many control strategies and performance estimation.The parameters are difficult to be calculated by regular approach because they are seriously affected by the cross saturation effects.To overcome the problem,taking the finite element method（FEA） as a powerful tool,different methods for calculating permanent magnet flux linkage and d-axis,q-axis inductances（Lad,Laq） were analyzed,and the cross-saturation effect which influenced Lad and Laq was also studied.It was shown that cross-saturation would cause mutual inductance between d-axis and q-axis,and permanent magnets arranged at the d-axis would also generate q-axis flux.A freeze element permeability method was proposed to linearization of the nonlinear field problem,and the steady-state parameters varying with d-axis and q-axis current were worked out.By comparing the actual test results and the simulated results using the calculated parameters,they all matched well in no-load and with-load conditions,it was revealed that the frozen permeability method was reliable.