并联型有源电力滤波器两种控制方法的性能分析

Performance Analysis of Two Control Methods in Shunt Active Power Filter

通过分析有源电力滤波器的补偿谐波的工作原理,提出了一种基于功率平衡双闭环的新型控制方法,将逆变器输出电流的参考值直接从负载电流中减去基波有功分量,消除了谐波检测的过程,控制更简单,但稳态误差大,动态稳定性差。在此基础上提出了基于瞬时无功理论负载谐波电流前馈的控制方法,采用三相锁相环对电网电压的相位进行跟踪锁定,使谐波电流检测、系统谐波及无功补偿更精确。通过Matlab仿真研究及对两种方法的性能进行对比,加负载谐波电流前馈能起到更好的补偿效果。

The principle of compensating harmonics of active power filter was analyzed,a novel dual-closed loop control methed based on power equilibrium was proposed,in which the output compensating current of inverter was acquired by subtracting basic active power current from the load currents.The method removes the process of harmonic detection,controls simplier but with bis steady-state error and poor dynamic stability performance.An improved load harmonic current feedforward control was proposed based on the instantaneous reactive power principle and three phase-locked loop was adopted to track the phase of power supply make the compensation more accurate.The results of Matlab simulation show that the proposed control strategy has good compensation performance.