A novel transformerless hybrid series active filter

This paper proposes a novel configuration of Series hybrid active filters. The proposed configuration could be connected to the grid without requiring a costly series injection transformer. This topology is capable of compensating current harmonics at the source and voltage distortion at the point of common coupling. Furthermore, an appropriate controller could compel the Transformerless hybrid series active filter (THSeAF) to perform as Unified power quality conditioner (UPQC) with quazi-similar behavior. The transformerless configuration is more cost-effective than any other series compensators based mostly on a transformer to inject the compensating voltages. Moreover, as a dynamic voltage regulator, the latter will compensate unwanted harmonics, unbalances, sags, and swells at terminals of a sensitive load. When performing as a series hybrid active filter, it cleans the power system from current distortions together with harmonics and unbalances, similar to a shunt active filter. The detailed operation of the proposed topology is presented and analyzed. Modeling and controller design are given. Validation by simulations of the system dynamic for different load and supply conditions is presented.