A New Decomposition Strategy for Analyzing Large-Scale Systems Such as Power Systems

TL;DR

This paper reveals that large-scale power systems have a feedforward-feedback control structure, analyzes their stability using nonlinear system tools, and introduces a methodology applicable to other interconnected nonlinear systems.

Contribution

It introduces a novel decomposition strategy that identifies and studies the feedforward and feedback components of large-scale nonlinear systems like power grids.

Findings

Power systems exhibit a feedforward-feedback control structure.

Stability can be analyzed using small gain and input-to-state stability theories.

Test results support the theoretical analysis.

Abstract

In this work, it is demonstrated that the usual power system dynamic model exhibits a feedforward-feedback control structure. The distinct properties of the feedforward and feedback subsystems are identified and studied using respective nonlinear system tools. The stability of the closed-loop system is investigated using a small gain argument from input-to-state stability theory. Test results are provided to further complement the theoretical findings. The introduced methodology also shed light on the dynamics study on other interconnected nonlinear systems.