Robustness against Disturbances in Power Systems under Frequency Constraints

TL;DR

This paper introduces a convex optimization-based method to efficiently assess power system robustness against disturbances while respecting frequency constraints, addressing the challenges posed by renewable integration and reduced inertia.

Contribution

It presents a novel, mathematically rigorous approach rooted in input-output stability analysis for Lur'e systems to certify power system stability under disturbances.

Findings

The method is non-conservative across IEEE test cases.

It provides a computationally efficient alternative to time-domain simulations.

The approach effectively characterizes external disturbances that maintain system stability.

Abstract

The wide deployment of renewable generation and the gradual decrease in the overall system inertia make modern power grids more vulnerable to transient instabilities and unacceptable frequency fluctuations. Time-domain simulation-based assessment of the system robustness against uncertain and stochastic disturbances is extremely time-consuming. In this paper, we develop an alternative approach, which has its roots in the input-output stability analysis for Lur'e systems. Our approach consists of a mathematically rigorous characterization of the external disturbances that the power system is transiently stable and the frequency constraints are not violated. The derived certificate is efficiently constructed via convex optimization and is shown to be non-conservative for different IEEE test cases.