降低有源部分容量的混合电力滤波器

Reduced rating of active filter in hybrid power filter

为了更经济地滤除电网中的谐波电流,提出了一种新型混合电力滤波器结构。与普通的混合滤波器相比,其有源滤波器的容量和成本进一步降低。由于无源滤波器承受了电网电压,而LC构成的基波谐振支路分流了无功电流,使得有源滤波器的额定电压和电流大大降低。在所提出控制策略的作用下,该滤波器可以有效地抑制电网谐波电压产生谐波电流并阻止负载谐波电流流入电网侧。由PSCAD/EMTDC软件进行仿真,结果表明:该结构中的有源滤波器的容量仅为滤波器总容量的2.11%,而滤波器投入后电网电流的总谐波畸变率仅为4.15%。

A novel hybrid power filter topology was developed to economically filter harmonic currents in power systems. The rating and cost of its active filter are less than conventional hybrid filters. A passive filter maintains the network voltage while the fundamental resonance branch shunts the reactive current, which greatly reduces the rated current and voltage of the active filter. With the control strategy, the filter keeps the harmonic system voltage from generating harmonic currents and effectively prevents the harmonic load current from flowing to the upstream system. PSCAD/EMTP simulation results show that the active filter rating accounts for only 2.11% of the total rating while the THD (total harmonic distortion) of the system current is reduced to 4.15% with the filter.