Robustness of Distributed Averaging Control in Power Systems: Time Delays & Dynamic Communication Topology

TL;DR

This paper analyzes the robustness of distributed averaging controllers in power systems, deriving delay-dependent stability conditions considering communication uncertainties, and demonstrating the trade-offs between robustness and performance through numerical examples.

Contribution

It provides the first delay-dependent stability conditions for DAI controllers under heterogeneous delays, link failures, and packet losses in power systems.

Findings

Derived delay-dependent stability conditions for DAI controllers.

Identified trade-offs between robustness and performance.

Validated conditions with numerical simulations on a test system.

Abstract

Distributed averaging-based integral (DAI) controllers are becoming increasingly popular in power system applications. The literature has thus far primarily focused on disturbance rejection, steady-state optimality and adaption to complex physical system models without considering uncertainties on the cyber and communication layer nor their effect on robustness and performance. In this paper, we derive sufficient delay-dependent conditions for robust stability of a secondary-frequency-DAI-controlled power system with respect to heterogeneous communication delays, link failures and packet losses. Our analysis takes into account both constant as well as fast-varying delays, and it is based on a common strictly decreasing Lyapunov-Krasovskii functional. The conditions illustrate an inherent trade-off between robustness and performance of DAI controllers. The effectiveness and tightness of our stability certificates are illustrated via a numerical example based on Kundur's four-machine-two-area test system.