Optimal design and analysis of anti-resonance C-type high-pass filters

Harmonic distortion is a matter of interest in all sectors of power system networks with their different voltage levels, particularly with the spread of harmonic-source nonlinear loads among all industrial, commercial, and domestic applications. One of the most important adverse effects of the harmonic distortion is the harmonic resonance, which may significantly amplify the harmonic voltages and currents. Thus, nowadays, the trend towards designing of new resonance-free schemes that can damp resonance and mitigate harmonics is rapidly growing. In this paper, optimal design and analysis of anti-resonance C-type passive filters are introduced taking into account the recent harmonic resonance quantification indices as the harmonic amplification ratios and the summed harmonic impedance-frequency index. An optimal design of the proposed filter is presented based on minimization of a weighted driving point impedance (WDPI) index using particle swarm optimization. The results validate the domination of the resonance damping capabilities of the C-type filters under both normal and worst operating conditions compared to the resonance-free third-order passive filters.