On the Use of Reachable Set for Safe Operation in Microgrid

Abstract

Microgrid is one of the new power supply systems expected for expanding introduction of renewable energy and improving the power quality. However, generators in a microgrid have risk at step-out because a microgrid utilizes many changeable power resources. For a safe operation in a microgrid, we evaluate reachable sets for unsafe sets of gas-engine generators according to a microgrid model. Reachable sets have already been applied to a study on air traffic management and electric power system. The unsafe sets are defined to avoid large deviations of rotor speed. Setting plurality of unsafe set, system's safe set can be obtained by calculating backward reachable sets for unsafe sets. This paper considers two compensation operations for load fluctuation. Based on the characteristic of reachable sets for unsafe sets, demand response strategy can be examined. Finally, numerical simulation shows that setting based on reachable sets can suppress the angular frequency variation of gas-engine generators in microgrid.