三相PWM整流器在电网电压不平衡时控制策略研究

Study on three-phase PWM voltage rectifier control strategy under the unbalance power grids

文中对电网不平衡的情况作出了分析.运用三相电网不平衡时的正、负序电动势理论,结合瞬时有功功率、无功功率的分析,阐述了抑制交流侧负序电流的控制策略.在该策略中,介绍并应用了一种分解正、负序电压的算法,并与传统的陷波器分解方法进行了比较,该算法可以准确地分解出正、负序电压分量.最后运用M atlab/S imu link构建了三相PWM电压型整流器仿真平台,仿真实验证明了控制策略的正确性.

In this paper, an analysis under the unbalanced power grids was introduced. In the light of the positive and negative sequence voltage theory, an unbalanced control strategy was adopted for restraining the negative sequence current at the alternating current side. In the strategy, an algorithm of decomposing the positive and negative sequence voltage was introduced and employed, and compared with the traditional way of notch filter. It has indicated that this algorithm can decompose the voltage correctly. A three-phase voltage source rectifier simulation platform was built with Simulink software, and the simulation results prove the correctness of the control strategy.