一种改进型的有源电力滤波器设计

Design of Active Power Filter Based on Robust H∞ Control

有源电力滤波器补偿精度是其重要的指标。现有基于鲁棒H∞控制的设计方法,其补偿精度与控制增益的幅值成正比,但较大的控制增益会造成内层控制过饱和(即占空比计算值大于1),因此补偿精度受到了一定的影响。针对这一现象,提出了一种采用H∞控制与PI(比例积分)和重复控制构成的复合控制相结合的方法。来提高有源电力滤波器的补偿精度,使得在控制增益较小的情况下,仍能获得较好的补偿效果。仿真实验证明了采用本设计的APF能够在系统参数摄动及死区干扰下仍然取得较好的补偿效果。

Accuracy is an important index for active power filter compensation. The active power filter using H∞ control strategy achieves better compensation effect when control gain is bigger. However,a bigger control gain causes the inner control oversaturated so that the compensation effect is decreased. Then the paper uses composite control strategy, which combines H∞ control with PI control and repetitive control, to eliminate the influence of parameter perturbation which causes state variables periodic disturbance. In fact, it can get a good compensation effect even in a smaller control gain. In the end, simulation results shows that the active power filter with the parameter perturbation and dead interference gets a good compensation effect by using the proposed method.