An Energy-based Modal Approximation Method for Reduced-order Modeling Analysis of Power System Models

Abstract

Recent works have examined the problem of modal reduction of power system linear models. In this article, a new model reduction technique for the analysis and control of inter-area oscillations in power systems which preserves exactly the inputs and outputs of interest of the original system, is presented. The technique combines the proper orthogonal decomposition and concepts from the balanced realization theory and can be used to analyze large power system models described by differential–algebraic equation systems. Methods for analysis of reduced system representations using linear approximations are critically reviewed and compared. The procedures developed are tested on a 16-machine, 68-bus dynamic equivalent of the New England test system. The effects of system dimension, accuracy of the approximations to capture inter-system oscillations, and generality of the techniques are discussed in detail in the parametric study. It is shown that the proposed techniques are more accurate than existing approaches.

Keywords:

• proper orthogonal decomposition
• modal approximation
• reduced-order modeling techniques