Extended Prony Analysis on Power System Oscillation Under a Near-Resonance Condition

TL;DR

This paper introduces an Extended Prony Analysis method for more accurate measurement-based modal analysis of power system oscillations, especially under near-resonance conditions caused by large disturbances, improving upon traditional methods.

Contribution

It develops a novel Extended Prony Analysis technique based on normal form theory to distinguish resonance modes from natural modes in power system oscillations.

Findings

Enhanced accuracy in modal property estimation under near-resonance conditions

Effective application demonstrated on Kundur's two-area system

Validated performance on IEEE 39-bus system

Abstract

Power system oscillations under a large disturbance often exhibit distorted waveforms as captured by increasingly deployed phasor measurement units. One cause is the occurrence of a near-resonance condition among several dominant modes that are influenced by nonlinear transient dynamics of generators. This paper proposes an Extended Prony Analysis method for measurement-based modal analysis. Based on the normal form theory, it compares analyses on transient and post-transient waveforms to distinguish a resonance mode caused by a near-resonance condition from natural modes so that the method can give more accurate modal properties than a traditional Prony Analysis method, especially for large disturbances. The new method is first demonstrated in detail on Kundur's two-area system and then tested on the IEEE 39-bus system to show its performance under a near-resonance condition.