Voltage stability of weak power distribution networks with inverter connected sources

Microgrids are power distribution systems in which generation sources are located close to loads. These small distribution networks represent a bottom-up approach for improving power security of critical loads that cannot tolerate disruptions in main grid service. Voltage stability becomes a significant issue in microgrids when the network interconnections are weak. This paper derives sufficient conditions for voltage stability of a weak microgrid with inverter connected sources. These conditions take the form of inequality constraints on various network parameters, loads and generation set points. These conditions can therefore be easily incorporated into optimal dispatch problems.