Energy Storage System with Dual Power Inverters for Islanding Operation of Microgrid

This paper proposes an energy storage system with dual power inverters for microgrid islanding operation. A primary inverter charges or discharges power to manage the energy storage in normal state, and a secondary inverter provides voltage instead of the grid in island state that is invoked when the grid is unavailable. The secondary inverter is stopped and standby in the normal state and runs rapidly at the grid fault. It has small capacity because it is rarely used, however it overcomes this disadvantage through an assistance of the primary inverter. The islanding operation of the system is verified using PSIM tool with an electrical circuit model and different logic controllers of the two inverters. The microgrid becomes islanded through a predefined sequence successfully.