Distributed control of heterogeneous energy storage systems in islanded microgrids : finite-time approach and cyber-physical implementation

Abstract

Microgrid (MG) is evolving towards a complex interacted cyber-physical system. In the physical layer, the energy storage systems (ESSs) are installed to mitigate the uncertainty of renewables. In the cyber layer, the distributed algorithms implemented on multi-agent systems are widely proposed to enhance system resilience and flexibility. Therefore, in this paper, a distributed control framework with the finite-time approach and cyber-physical implementation is proposed for ESSs with heterogeneous parameters in islanded MGs. With the proposed control framework, the fair power sharing and state-of-charge balancing among ESSs can be accomplished in finite-time. In the meantime, the MG secondary control objective of frequency and voltage restoration is also achieved. The stability of the proposed controllers is proved via the Lyapunov method. Towards the practical application, the MG entities and primary controllers, as the physical system, are emulated in OPAL-RT, while the distributed finite-time algorithms and multi-agent system, as the cyber system, are realized in multiple Raspberry Pis. The cyber hardware-in-the-loop experiment results demonstrate the effectiveness of the proposed controller design under various scenarios.