Continuous operation of micro-inverter for constant supply in grid connected and off grid operation

In this paper, a photovoltaic (PV) micro-inverter capable of operating in both off-grid mode and grid-connected mode is proposed. The main advantage of this system is that in grid-connected mode, the micro-inverter works as grid tied micro inverter which will receive power from the grid if the load is more and supply power to the grid if the connected load is less this is the operation mode of most commercial grid-connected PV micro-inverters. The idea is to provide those micro-inverters with the additional functionality of working in off-grid mode without changing their control algorithms for grid-connected mode, which were developed and refined over time. In this system if the power supply from the grid is interrupted the micro inverter will start working as off-grid mode. This system will isolate the grid from the micro inverter without supplying any power to the grid and its full concentration will be to the connected local load. If the connected load is low the micro inverter will charge the small battery connected as the dummy source, if no load is connected across the micro inverter it will stop working by switching off the solar panel from the micro inverter.