Location Method for Forced Oscillation Sources Caused by Synchronous Generators

TL;DR

This paper introduces a novel method combining dynamic state estimation and energy flow analysis to accurately identify and locate the sources of forced oscillations in power systems caused by synchronous generators.

Contribution

It proposes a new methodology that utilizes DSE and DEF to distinguish whether oscillations originate from excitation systems or turbine governors, even with limited measurement data.

Findings

Method effectively identifies oscillation sources in simulations.

Applicable to non-stationary signals in power systems.

Provides systematic approach for oscillation localization.

Abstract

In this article, we present a new methodology to identify if forced oscillation sources are generated in excitation systems or in turbine governors. In this context, we propose to harness the information that the dynamic state estimation (DSE) provide to be able to apply a dissipating energy flow (DEF) method. The measurements that the phasor measurement units (PMUs) provide are used to estimate the internal states of different generators connected to the same bus. Here, it will be considered that the PMU at the point of connection is only capable of measuring the voltage phasor and the total current phasor. Therefore, the current injection of the generator that is causing the FO is an unobservable variable. To overcome this issue, event playback is applied to simulate the model's response and a comparison between the DSE of multiple generators is made. Finally, when the faulty generator is identified, we compute energy functions for the mechanical control loop and for the excitation control loop. The sign and rate of these energies determine the source of the oscillation, allowing that the FO can be located. Simulated signals are used to show that the proposed method provides a systematic methodology for identification and location of power systems forced oscillations than even could be non-stationary signals.