Protection algorithms of microgrids with inverter interfaced distributed generation units-A review

Microgrids are emerging as a crucial component of the modern power system owing to significant developments in renewable energy-based distributed generation technologies and worldwide growing concern about the environmental hazards caused by the conventional coal-based power generation units. However, the addition of the distributed generation units and the ability of the microgrids to operate both in the grid-connected mode and the islanded mode have thrown a new set of challenges for the protection researchers because of the bidirectional power flow, uncertainty about the amount of power flow and wide variations in the fault current magnitude depending upon a variety of factors such as mode of operation, the structure of the network, and type, rating, location and number of distributed generation units. In this work, the challenges in the protection of a microgrid system with both inverter interfaced distributed generations (DGs) and synchronous generator based DGs are analysed and a comprehensive review of the available algorithms used for feeder protection in the microgrid is presented.