Improved ZSI-based DVR for Power Quality Improvement in Grid Connected PV Systems

Abstract

Power Quality (PQ) is a major concern while integrating the Distributed Generation plants with the grid. This article describes a novel Fuzzy Logic Controller (FLC) with a Z-Source inverter (ZSI) based Dynamic Voltage Restorer (DVR) to improve the PQ of grid-connected Photo Voltaic (PV) systems. DVR is a series-connected IGBT-based Voltage Source Inverter (VSI) designed to compensate for voltage-related power quality concerns such as sag and swell. ZSI obtained superior benefits of buck/boost converter-based DVR in the proposed FLC with DVR than regular VSI. In the instance of a PV system, a hybrid unit vector controller is proposed for efficient detection, accurate voltage disturbance mitigation and also for reducing injected voltage harmonics under severe sag, slight sag with harmonics, swells and interruption. The efficiency of the suggested ZSI-DVR has been demonstrated by comparison research and simulation results, VSI-DVR and ZSI-DVR are traditional DVRs. The PV system ZSI-DVR has reduced voltage sag/interruption/swell. The power quality of the total system is improved compared to existing methods.