Distributed transient frequency control in power networks

TL;DR

This paper proposes a distributed control method for power networks that ensures transient frequency safety and system stability, addressing challenges posed by low inertia and dynamic units.

Contribution

It introduces a novel distributed control strategy based on Lyapunov stability and set invariance, specifically designed for transient frequency regulation in power networks.

Findings

Successfully maintains transient frequencies within safe limits.

Ensures asymptotic stability of the entire power system.

Demonstrated effectiveness on IEEE 39-bus network simulations.

Abstract

Modern power networks face increasing challenges in controlling their transient frequency behavior at acceptable levels due to low inertia and highly-dynamic units. This paper presents a distributed control strategy regulated on a subset of buses in a power network to maintain their transient frequencies in safe regions while preserving asymptotic stability of the overall system. Building on Lyapunov stability and set invariance theory, we formulate the transient frequency requirement and the asymptotic stability requirement as two separate constraints for the control input. Hereby, for each bus of interest, we synthesize a controller satisfying both constraints simultaneously. The controller is distributed and Lipschitz, guaranteeing the existence and uniqueness of the trajectories of the closed-loop system. Simulations on the IEEE 39-bus power network illustrate the results.