Publication

Abstract : Droop control is widely used for inverter dominated microgrid due to its simplicity and lack of expensive communication interfaces. It mimics the governor action of alternator by controlling frequency and magnitude of voltage to regulate active and reactive power flow respectively. A reduced order small signal model is developed for a microgrid system with two inverters, two interconnecting lines and three loads. The stability of the system is improved by the optimal setting of droop gains using particle swarm optimization after defining suitable objective function. The eigenvalues which are present near imaginary axis are shifted towards left using state feedback control for improving stability. Hence a new control scheme is proposed in this paper by combining state feedback control with droop control to improve the transient performance. The response of the system for change in load current verifies the effectiveness of the proposed control method.