A novel switching method in PV‐fed quasi‐ZSI‐DVR for voltage quality enhancement of photovoltaic integrated networks

Abstract

AbstractIn this work, a novel switching method for the photovoltaic‐fed (PV‐fed) dynamic voltage restorer (DVR) system based on a quasi‐Z‐source inverter (quasi‐ZSI) is proposed. This proposed switching control strategy is implemented in such a way that a wider voltage boost gain and lower voltage stress across the switches and capacitors are achieved. The major drawback with the traditional switching method is that always three switches will be in conduction. However, in the proposed switching method, only two switches are triggered simultaneously to achieve the required output. It also obviates the need for zero states. The proposed switching method for the PV‐fed quasi‐ZSI‐DVR provides an accurate compensation for various voltage disturbances, such as sags, swells, and interruptions, thereby eliminating the voltage harmonics at the point of common coupling. The integration of PV and battery is suggested for the quasi‐ZSI‐DVR to tackle the pertinent issue regarding sporadically transferring energy in the PV arrays and also recharging of batteries. Simulation and experimental results validate the suitability of the proposed PV‐fed quasi‐ZSI‐DVR configuration with the proposed switching control method. It is inferred that the proposed system provides the lowest voltage harmonics and additional benefits like smaller capacitors, higher voltage gain, and lower voltage stress rates.