Active power filter equivalent to an infinite feeder for harmonic suppression in radial distribution systems

This study proposes to install a novel active power filter (IF‐APF) mimicking the character of an infinitely long transmission line at the end of a radial feeder. The proposed IF‐APF eliminates the reflected wave and realises the background harmonic voltage suppression capability throughout the feeder by mimicking the characteristic of an infinite feeder. The proposed IF‐APF shows a better harmonic damping performance than the traditional resistive active power filter (R‐APF). Moreover, the proposed IF‐APF achieves a better harmonic suppression performance than the traditional R‐APF, especially when the characteristic impedance of the feeder changes or there are non‐linear loads. Simulation and experimental results verify the theoretical analysis and demonstrate the effectiveness of the proposed IF‐APF.