采用全局交叉耦合法计算永磁电机dq轴电感及特性

Calculation of D-axis and Q-axis Inductances and Characteristics of PM Motor by Global Cross-coupling Method

永磁电机dq轴电感计算的准确性决定了电机特性计算的准确性。为了研究电感精确计算方法,提出一种预测dq轴磁链、端电压及电磁转矩的方法,以某电动汽车电机为研究对象,利用电机有限元模型并考虑交叉耦合效应计算出不同id,iq下的dq轴电感,进而计算电机关键特性,依此可较容易地确定电机的电磁性能。利用该方法计算的电机dq轴电感与采用冻结磁导率方法的计算结果基本一致,所计算出电机的转矩-转速特性、效率Map图等关键数据也与实测结果基本吻合,证明了该计算方法的有效性。

Calculation accuracy of the PM motor＇s characteristics depends on the accuracy of the calculation for d-axis and q-axis inductances. In order to research the exact calculation method, a 2D FEM model was built based on an electric vehicle motor. Ld and Lq was calculated based on the d-axis and q-axis flux linkage model, taking global cross-coupling effect into account. Ld and Lq were calculated again by the method of the frozen permeability and the results were in accordance with the ones by cross-coupling method; moreover, the calculated results of key parameters such as the character of torque and speed, efficiency map, etc are nearly identical with the practical test results, which verified the validity of the calculation method.