Operation and Control of Single-Phase Distributed PV-Battery Microgrid for Smooth Mode Transition with Improved Power Quality

In this work multiple parallel photovoltaic (PV) inverter based microgrid developed to enhance the reliability and accessibility of electricity in remote areas. The employed microgrid structure designed to operate in the grid connected mode (GCM) as well as isolated mode (IAM) and vice-versa. In this microgrid, (PV)-battery interfaced main inverter with a smooth mode transition control in parallel with a PV supported inverter with an enhanced current control is considered to operate under the grid connected conditions and in the off-grid mode of operation. In IAM, the main PV-inverter works as grid forming inverter and maintained constant voltage and frequency across the load to meet the power quality for the continuous operation of local nonlinear load. The battery storage units support the PV units during peak load periods and maintain the power balance in the microgrid. Controlled charging and discharging profile of battery is achieved by the DC-DC bidirectional converter (DBC). The control strategy of microgrid has been verified with simulations are offered in this paper.