A distributed optimal active power control scheme for inverter-based islanded AC microgrids

Abstract

This paper presents a distributed optimal active power control strategy for inverter-based islanded AC micro-grid with both droop-controlled and PQ-controlled distributed generators (DGs). Each DG is considered as an agent which can exchange information with neighbouring agents through a distributed peer-to-peer communication network. A distributed economic dispatch (ED) algorithm with fixed-time convergence is proposed to calculate the optimal active power references for each DG and the algorithm is rigorously proved by applying Lyapunov theory. Based on the ED references, the key parameters of droop controller and PQ controller are updated in real time, which makes each DG track the corresponding optimal active power reference. The frequency of islanded microgrid is automatically restored to the nominal value. Simulation results are provided to illustrate the effectiveness of the proposed distributed control strategy.