A novel control method of PAPF for resonance damping and harmonics compensation in power system

In power system, capacitors are widely used to compensate reactive power, which generally cause resonance problems in harmonic distorted network. In this paper, parallel active power filter (PAPF) is used to damp the resonances. Firstly, the damping characteristics of PAPF with traditional load current detection methods (detecting current including or not including the capacitor current) are analyzed respectively. The analysis results show that PAPF with traditional load current detection methods is effective for parallel resonance damping, but can not damp series resonance when capacitor current is not included in the detecting current. And when capacitor current is included in the detecting current, PAPF is prone to be unstable and can not damp parallel and series resonance. Then a novel control method of PAPF is proposed. PAPF with the proposed control method has excellent performance in damping of both parallel resonance and series resonance, whether the capacitor current is included in the detecting current of PAPF or not. Also the PAPF with proposed method has strong ability in harmonic compensation. Finally, the experiment results are presented to verify the analysis.