有源电力滤波器直流侧母线电压控制策略研究

摘要

电网电压绝对的平衡状态不存在,故需考虑电网电压不平衡对有源电力滤波器(APF)工作造成的影响.基于三相三线制APF拓扑结构进行研究,介绍了APF交、直流侧能量转换的机理,分析了纹波电压存在的原因及其构成成分,解释了电网不平衡时纹波电压增大的原因.针对该问题提出了一种改进的APF直流侧电压控制方法,用来抑制负序分量引起的纹波电压增加.最后通过实验验证了控制方法的正确性和有效性.%Absolute balance of the grid voltage does not exist.Therefore,it is necessary to consider the influence of active power filter(APF) work caused unbalanced grid voltage.Three-phase three-wire APF is taken as research object,the mechanism of energy conversion between AC/DC-side of APF is described and the causes and constituents of rippie voltage across the capacitance are analyzed.Reasons for the increased voltage ripple under unbalanced grid voltage are explained.An improved DC-side voltage control strategy under unbalanced grid state is presented to suppress the increased ripple voltage due to negative sequence component.This improved control strategies is available to the case of three-phase voltage asymmetry.The correctness and effectiveness of the control method is verified by experiments.