Real-Time Implementation of a Three-Phase THSeAF Based on a VSC and a P+R Controller to Improve the Power Quality of Weak Distribution Systems

This paper proposes a novel three-phase transformerless hybrid series active filter (THSeAF) based on voltage-fed type of converters (VSCs) to address major power quality issues related to residential and commercial buildings. This power quality compensator presents an affordable solution to overcome current-related issues as well as integrating renewables to ensure a sustainable supply to the loads. The controller is based on a novel combination of the synchronous reference frame and pq theory to extract voltage and current harmonics as well as voltage unbalances. A proportional resonant (P+R) regulator is producing gate switching signals for the three-phase THSeAF. The generated duty-cycle waveforms will produce compensating voltage to rectify harmonic currents initiated from typical nonlinear loads. The device ensures a reliable and dynamically restored power supply on the load's point of common coupling by means of three auxiliary dc supplies. This paper describes mitigation of power-quality-related issues of a microgrid systems and smart distribution grids along with the proposed solution to enhance the power system performances. A combination of simulations and experimental laboratory results are carried out to validate the study.