Power Quality Improvement in Micro Grids by Using Multi-Inverter Based UPQC with Fuzzy Controller

Abstract

This work introduces a Unified Power Quality Controller (UPQC) employing an Artificial Neural Network (ANN) for enhanced performance. The UPQC effectively compensates for unbalanced grid and load voltages within the power system. Specifically designed for grid integration of photovoltaic systems, the UPQC, guided by an ANN controller, addresses issues such as voltage sags/swells, unit power factor correction, and voltage and current harmonic cancellation.In the context of a power distribution network, this UPQC system concurrently rectifies supply voltage and load voltage irregularities. The unit vector template control algorithm incorporates a phase-locked loop (PLL) mechanism to prevent multiple zero crossings during the detection of highly distorted grid voltages. Applied to both shunt and series inverters of the photovoltaic grid-connected UPQC, the unit vector template control with PLL-based algorithm ensures effective regulation of grid and load voltage unbalances. Furthermore, the UPQC, guided by the ANN controller, controls the Total Harmonics Distortion (THD) of both grid and load voltages.