Control for Inverter Power Sources in a Standalone Microgrid

Abstract

Fuel cells and photovoltaic systems are increasing in distribution networks for reduction of CO₂ emission. These power sources require inverters to connect to ac network. There is a possibility that sub-network, called as microgrid, containing inverter power sources will be disconnected from the utility network and operated as standalone mode. This paper focuses on a standalone microgrid supplied by inverter power sources without synchronous generator, and proposes new inverter control in the microgrid. The feature of the inverter control is that one inverter is operated as a master power source mainly determines frequency and voltage, and the other inverters are operated as subordinate power source with active and reactive power control. Coordinated operation of all inverters in the microgrid is obtained.