基于双阻性有源滤波器的背景谐波抑制策略

电力系统中线路电感与电容之间的谐振使得电力系统背景谐波电压放大,严重影响电能质量。针对传统技术中在传输线终端安装与其特征阻抗匹配的阻性有源滤波器(RAPF)只能抑制谐波放大、不能有效衰减谐波的问题,提出新的基于双RAPF的谐波抑制方案,即在传输线终端安装与其特征阻抗匹配的RAPF1,在距离传输线始端主要谐波1/4波长的位置设置电导增益可变的RAPF2。该方案对由上级电网渗透的谐波电压和本级电网的谐波电流引起的电压畸变均有很好的抑制效果。仿真与实验结果验证了理论分析的正确性和该策略的有效性。

Background Harmonic Suppression Based on Double Resistive Active Power Filters

Series and parallel resonances between capacitance and line inductance may magnify background harmonic voltage in power distribution systems, and worsen power quality. Although a resistive active power filter (RAPF) acting as a harmonic terminator can damp out harmonic propagation, it fails to attenuate the existed harmonic effectively. Thus, this paper proposes a double-RAPF strategy. Besides a RAPF1 with matching impedance is located on the end bus, the new strategy involves an additional RAPF2 with variable gain at special location whose distance from the source of the feeder is a quarter wavelength of the dominant harmonics. The proposed strategy can suppress the harmonic propagation caused by harmonic voltage penetrating from the higher level system and harmonic current injected by non-linear loads. Simulation and experimental results verify the theoretical analysis and demonstrate the effectiveness of the new strategy.