并联有源电力滤波器典型重复控制策略的分析与改进

摘要

Currently , the typical repetitive control used in shunt active power filter is normally composed of PI control and paralleling repetitive control .The application of this method is often limited due to the low open-loop gain in mid-dle band and the worse dynamic compensation effect caused by the PI controller existed in both the forward and feed -back channel .An improved repetitive control strategy is proposed in this paper , a PI controller is used to form the in-ner current loop with the purpose of correcting the response characteristics in middle and low frequency bands to im -prove the robustness of the control system .The high gain for harmonic signals is obtained by the repetitive control in the forward channel , and thus the expansion of middle bandwidth is improved .The dual current loop consists of PI in-ner current loop and repetitive control .The reference current feed forward to the PI inner current loop is designed to improve the response speed of APF .Finally, the simulation and experiment results verify the correctness and effective-ness of proposed control strategy are given .%目前并联有源电力滤波器采用的典型重复控制通常由PI控制与重复控制并联构成，存在中频段开环增益不足的缺点，且PI控制器同时存在于前向通道与反馈通道中，动态补偿效果不佳。提出了改进的重复控制策略，利用PI控制构成电流内环，对控制对象的中低频段特性进行校正，提高控制系统鲁棒性。利用前向通道中的重复控制器提供对谐波信号的高增益，提高了有源电力滤波器的中频段带宽。同时利用参考电流信号前馈至PI控制电流内环，充分保证控制系统的动态性能。仿真和实验结果验证了所提出控制策略的正确性和有效性。