Distributed, Bounded and Finite-Time Convergence Secondary Frequency Control in an Autonomous Microgrid

Abstract

To accommodate the intermittent renewable generations and constantly changing load demands, a proper control approach with flexible convergence time is desirable for an autonomous microgrid. This paper proposes a distributed, bounded, and finite-time convergence secondary control for frequency restoration and accurate active power sharing in an autonomous microgrid. The control input is designed to be distributed and bounded. The finite-time convergence proof and convergence time upper bound are guaranteed by rigorous analysis. Moreover, an approximation method is proposed to achieve a less conservative convergence time upper-bound compared with that of the traditional method. The effectiveness of the proposed control algorithm is validated through simulations with a modified IEEE 5-bus system and extended to a modified IEEE 39-bus system for scalability analysis.