Harmonic Analysis and Detection of Power System based on Double Moment Wavelet Transform

Abstract

The influence of unbalanced installation of single-phase DG unit with harmonic compensation function in three-phase and three-wire public power grid shows that there will be risk for the unbalanced installation to increase the three-phase current of the power grid. In order to overcome this problem, balanced triple-frequency harmonic function is proposed for the purpose of avoiding the increase in three-phase power grid current. In addition, compared with the traditional method, such method is also capable of reducing the rated power of harmonic current compensation. In order to verify the effectiveness of the method proposed, the balance and unbalanced conditions are verified in experiment and the experimental circuit is a simplified system based on actual three-phase three-wire system. In order to avoid the increase in the harmonic current, a balanced third harmonic suppression method is proposed. Finally, performance of the algorithm proposed has been verified through experiment.