Distributed event-triggered voltage restoration and optimal power sharing control for an islanded DC microgrid

Abstract

This paper proposes a distributed voltage restoration and power allocation control scheme for the DC microgrid (MG) system, which only relies on discrete and aperiodic event-triggered communication. Different from most existing control approaches, we attempt to break the hierarchy of secondary control and tertiary optimization, and solve the optimal power regulation and voltage restoration problems simultaneously in the secondary layer. Specifically, a distributed controller with event-triggered communication strategy is developed by not only considering the secondary voltage restoration error but also taking the Karush–Kuhn–Tucker (KKT) condition of tertiary power allocation optimization problem into account. In addition, compared to most distributed secondary control methods with continuous-time communication, our approach can still realize the same objectives only with limited noncontinuous communication, which would benefit us a lot in communication cost saving. An islanded DC MG test system consisting of three DGs is built in both Simulink and the laboratory to validate the proposed control scheme’s effectiveness.