A Dual Inverter Configuration for PV-BES Based Microgrid in GI and SA Modes

Abstract

This paper presents a double-stage solar photovoltaic (PV) and battery energy storage (BES)-based three-phase microgrid in grid-interfaced (GI) and standalone (SA) modes. The battery is connected to a separate voltage source converter (VSC) through a bidirectional converter (BDC) and DC link capacitor. The VSC connected to the solar PV array always operates in current control mode. The VSC connected to the battery operates in current control when the microgrid is interfaced to the utility grid; else, it operates in voltage control mode. The battery-VSC unit operates as grid forming inverter in SA mode. A sparse variable step size least mean square (SVSSLMS) algorithm is used to estimate load current’s active fundamental weight to obtain improved power quality.