LAUSR

Abstract Islanded microgrids can experience severe frequency variation due to their inherently low inertia. Virtual inertia has been proposed in the literature to overcome this shortage. Virtual Synchronous Machine (VSM) concept has been the cornerstone of realizing virtual inertia from inverter connected energy sources. In this paper we propose and solve an optimal control problem to identify the optimal switching controls that achieve best dynamic frequency response from VSM. The results show that the optimal number of switching stages is independent of system parameters, and the optimal timing for switching between two control modes can be determined using local measurements alone, without having to perform complex computations.