Distributed Frequency Restoration and SoC Balancing Control for AC Microgrids

TL;DR

This paper presents a distributed finite-time control algorithm for AC microgrids with BESSs that ensures frequency regulation and SoC balancing efficiently, with reduced communication and guaranteed stability.

Contribution

It introduces an improved control algorithm with an event-triggered mechanism for AC microgrids, enhancing stability, convergence speed, and communication efficiency.

Findings

Achieves accelerated convergence within a fixed settling time.

Effectively balances SoC and maintains frequency stability.

Reduces communication load through event-triggered control.

Abstract

This paper develops an improved distributed finite-time control algorithm for multiagent-based ac microgrids with battery energy storage systems (BESSs) utilizing a low-width communication network. The proposed control algorithm can simultaneously coordinate BESSs to eliminate any deviation from the nominal frequency as well as solving the state of charge (SoC) balancing problem. The stability of the proposed control algorithm is established using the Lyapunov method and homogeneous approximation theory, which guarantees an accelerated convergence within a settling time that does not dependent on initial conditions. Based on this, to significantly reduce the communication burdens, an event-triggered communication mechanism is designed which can also avoid Zeno behavior. Then sufficient conditions on the event-triggered boundary are derived to guarantee the stability and reliability of the whole system. Practical local constraints are imposed to implement the control protocol, and the theoretical results are applied to a test system consisting of five DGs and five BESSs, which verifies the effectiveness of the proposed strategy.