永磁同步电机直接功率控制基本原理

Basic Theory of Direct Power Control for PMSM

在对永磁同步电机有功功率和无功功率与系统稳定运行所需转矩和磁链之间的内在关系进行分析的基础上,提出了永磁同步电机基于开关表的直接功率控制新方法。该方法通过计算瞬时有功功率和瞬时无功功率的两个滞环输出,并根据定子磁链所在的扇区,从瞬时功率开关表中查询出合适的开关电压矢量进行输出,从而对瞬时功率进行直接控制。本文以无功功率等于零为控制目标,即需把无功功率控制在零附近很小的范围内波动,使得在电机输出同样有功功率的条件下,提高了电机的功率因数,使无功功率降到最小,达到了节能的目的。仿真和实验结果证明了该控制方案的有效性和正确性,该方法在节能电机驱动系统中有着广阔的应用前景。

Based on the analysis of relationship of the active power, reactive power, torque and stator flux-linkage, a new direct power control（DPC） method for permanent magnet synchronous machine is presented in this paper. It selects optimum voltage vector to control the instantaneous power through optimum switching table which based on the sector of flux linkage and the output of the active and reactive power hysteresis. The goal of the method is to control reactive power as zero and improve power factor at the same output of active power. Both the results of simulation and experiment show the good performance and accuracy of the proposed method. Especially, this method has good application prospect in energy saving motor driven systems.