基于CE-FEA和小信号分析快速计算逆变器供电下聚磁式场调制电机中永磁体涡流损耗

Fast Calculation of PM Eddy Current Loss in FCFMPM Machine under PWM VSI Supply Based on CE-FEA and Small-Signal Analysis

提出一种结合高效有限元法、频域小信号分析和矩形永磁体涡流损耗解析计算模型,快速计算电压源型逆变器供电下聚磁式场调制永磁电机中永磁体涡流损耗的方法。基于高效有限元法,仅需进行一步静态有限元计算即可构建出永磁体中主要低频交变磁通密度分量。基于小信号分析,仅需进行四步时谐有限元计算即可获得脉宽调制电压谐波与永磁体中高频交变磁通密度之间的关系。进而结合解析计算模型实现永磁体涡流损耗的快速计算。所提方法考虑了轴向分段和高频涡流反应对永磁体涡流损耗的影响。与传统时步有限元法相比,所提方法的低频谐波损耗计算相对误差小于4%,脉宽调制谐波损耗计算相对误差小于8.4%,计算速度提高了数百倍以上。

In this paper,a method for fast calculating the permanent magnet(PM)eddy current loss(ECL)in a flux-concentrating filed-modulated permanent-magnet(FCFMPM)machine under pulse width modulation(PWM)voltage source inverter(VSI)supply is proposed,which is based on the computationally efficient finite element analysis(CE-FEA),the frequency-domain small-signal analysis,and the analytical ECL model for the cubic PM.The major low-frequency components of the flux density waveform can be constructed with the result obtained form only one-step time-stepping finite element analysis(TSFEA)based on the CE-FEA.Besides,the relationship between PWM harmonic voltages and the flux density variations in the PM can be obtained with four-steps time-harmonic FEA based on the small-signal analysis.Then,the PM ECL can be fast computed with the analytical PM ECL model.The influence of axial segmentation and the eddy current reaction effect have been considered in the proposed method for the PM ECL calculation.Compared with the traditional TSFEA,the calculation speed of the proposed method improves hundreds of times while the relative error of the low-frequency ECL is within 4% and that of the PWM harmonic ECL is limited to 8.4%.