检测电流包含电容电流的SAPF谐波抑制和谐振阻尼新方法

摘要

Firstly, this paper presents a hybrid compensation system with shunt active power filter (SAPF) and power capacitors. However, parallel resonance between inductive grid impedance and capacitive impedance will occur in this system. With traditional method, hybrid system is stable when capacitor current is not included in the detected current. But, when capacitor current is included, the detected current will be amplified and resonance frequency will be shifted to higher frequency. Then, an improved method that reversing part of SAPF compensation reference current whose spectra higher than resonance frequency is proposed. Points of common coupling (PCC) voltage is also detected for resonance damping which is helpful to mitigate harmonic distortion. At last, simulation and experiment results are presented to verify the proposed method.%研究一个由并联型有源电力滤波器(SAPF)和并联电容器组成的混合补偿系统,其中并联电容器的容性阻抗会与配电网的感性阻抗发生并联谐振.当检测电流中不包含电容电流时,SAPF可以抑制谐波和阻尼谐振且系统稳定;当检测电流中包含电容电流时,SAPF采用传统方式补偿会使得系统谐振频率向高频漂移.针对SAPF检测电流包含电容电流情况,提出一种改进的控制方法.该方法基于谐波电流分频控制策略,将高于谐振频率的抑制电流指令取反,低于谐振频率的抑制电流指令保持不变,同时检测谐振频率附近的公共耦合点(PCC)电压构建虚拟阻尼电阻,并对虚拟电阻的电导值进行闭环调节.采用该方法补偿后的网侧电流和PCC电压均满足电能质量标准.最后进行了仿真和实验验证.