Comparsion of Harmonic Propagation and Whack-a-mole Phenomena Compensation on Radial Distribution Feeder Using Parallel Active Power Filter with Constant and Controlled Gains

In order to damping harmonic propagation effect, the active power filters (APF) are installed on distribution systems. This installation also may cause harmonic oscillation effect named Whack-a-mole. In this paper using simulation results, the two mentioned effects are decreased efficiently for a ten-bus power radial distribution feeder for any nonlinear load connections (harmonic current or voltage source) by using constant gain Kv=1/Zc The characteristic impedance, Zc, is nondeterministic and variable, so the APF's gain should be controlled actively. In this paper the parallel active filter gain is designed such that by producing proper compensating current, the harmonic distortion on APF bus is controlled and the harmonic propagation and oscillation effects are prevented by keeping the harmonic distortion in an allowable interval. By adjusting APF gain, the effective compensation current will decrease and so the power loss and cost, the benefit of applying adjustable gain APF.