Integrated one-cycle control for three-leg universal active power filter

The power quality in grid is being deteriorated by the proliferation of nonlinear loads such as static power converters. The single-phase four-leg universal active power filter uses matching transformer, bulky and inadequate for commercial and household applications. This paper deals with a single-phase three-leg universal active power filter, without any transformer, which is controlled by OCC strategy. Besides a reduced count of components with reduced switch voltage stress, the proposed controller has fast response, stability, low cost, and operates near unity power factor.