A distributed voltage unbalance compensation method for islanded microgrid

Abstract

This paper presents a distributed secondary control scheme for voltage unbalance compensation in the islanded microgrid (MG) systems. Conventionally, the voltage unbalance compensation is realized in a centralized way, which has certain intrinsic disadvantages such as poor fault tolerance ability and higher computational and communication cost. In order to overcome these drawbacks, a distributed secondary control scheme for voltage unbalance compensation is proposed. A finite-time average consensus algorithm is used for each local controller to obtain global information. The proposed scheme not only achieves similar voltage unbalance compensation performance as the centralized one but also shares the compensation efforts among local compensators dynamically in a distributed fashion. In addition, our proposed scheme has fault tolerance ability in the sense that when some compensators fail to work, the rest compensators can still ensure balanced voltage output in the sensitive load bus (SLB). Simulation results are presented to validate our proposed scheme.