PMSM矢量控制下逆变器母线电流频谱分析

Inverter DC Link Current Spectrum Analysis for PMSM Based on Vector Control

摘要:

逆变器直流母线电流频谱的准确解析是对电磁干扰进行分析及母线电容选取的重要理论基础。针对永磁同步(PMSM)作为负载时逆变器直流母线电流频谱的数学表达和理论求解方法分析了相电压基波和高次谐波对应的等效阻抗。分析得出:非凸极PMSM各次谐波对应的视在电感相等并且恒定；凸极式PMSM的基波电流可以在直轴和交轴上进行相量分解，其对应电感为直轴和交轴电感，高次谐波对应的电感随着转子的位置变化。理论计算时可以通过忽略高次谐波或取平均电感的方法来进行近似。给出了母线电流频谱计算的方法与过程。仿真和实验都证明了本文给出的计算方法及公式的正确性和有效性。

Abstract:

The accurate analysis of the inverter DC link current is the key to the assessment of the electromagnetic interference and computation and selection of the DC link capacitance. Aiming at the mathematical expression and solving method to the inverter DC link current for PMSM based on vector control, the paper analyzed the corresponding equivalent inductances for the fundamental wave and the high order harmonics of the phase voltage. The results show that the equivalent inductances for all the harmonic waves of the salient pole PMSM are equal and constant, the equivalent inductances for the high order harmonics of non-salient PMSM are changeable with the rotator position, and the fundamental wave can be decomposed on the d-axis and q-axis by phasor synthesis and the corresponding inductances are d-axis inductance and q-axis inductance. In the theoretical computation, the high order inductances can be regarded as a constant through averaging method or the high order harmonics can be abandoned. The correctness and effects were verified through the simulation and experiment.