A Hybrid Filter for Wideband Frequency Harmonics Eliminating

A hybrid filter (HF) which contains a passive part and an active part is proposed to eliminate wideband frequency harmonics ranging from low-order harmonics to high-order harmonics in high-voltage occasions. To decrease the capacity of the active part, the active part is connected in series with the fundamental parallel resonance circuit and, thus, greatly reduces its voltage ratings of active part. The passive part made up of fundamental parallel resonance circuit (PRC1), resistance R1, 3rd harmonic parallel resonance circuit (PRC3) and 5th harmonic parallel resonance circuit (PRC5) connected in series, acts as a filter which filtering the high-order harmonics. Furthermore, the configuration of PRC3 and PRC5 can block 3rd and 5th harmonic currents flowing through itself, which ensures a better compensation for the low-order harmonic currents. The simulation and a small-scale protype are built. The simulation and experimental results verify that the proposed HF has a better compensation effect to the wideband frequency harmonics.