Rating analysis and design of coupling transformer for single-phase parallel hybrid active filter

This paper introduces a parallel hybrid active filter topology and operation principle appropriate for removing harmonics caused by single-phase nonlinear loads. Based on the characteristic of the coupling transformer of a parallel hybrid active filter, a simple method for estimating VA rating is proposed. Furthermore, by means of parameter transform, this paper presents a new design strategy for designing this kind of the transformer as a line frequency transformer. Experimental results obtained from a 1 MVA laboratory prototype verify the viability and effectiveness of these methods proposed in this paper.