Data-driven Forced Oscillation Localization using Inferred Impulse Responses
Shaohui Liu, Hao Zhu, Vassilis Kekatos
TL;DR
This paper tackles the problem of locating forced oscillation sources in interconnected power systems by leveraging ambient PMU data to recover system impulse responses without relying on a detailed grid model. The core idea is to formulate FO localization in the Fourier domain as a least-squares problem using impulse responses recovered from ambient data, guaranteeing a theoretical link to linearized dynamics under reasonable assumptions. The authors develop a two-phase algorithm—offline impulse-response recovery from ambient measurements and online FO localization from FO data—that is flexible to measurement types and partial observability. Numerical tests on the IEEE 68-bus system and the NASPI 240-bus dataset demonstrate high localization accuracy across scenarios with single or multiple FO sources and modes, including partial observability and non-generator FO sources. The approach offers a scalable, data-driven alternative to model-dependent methods with practical applicability for real-world grid monitoring and FO mitigation.
Abstract
Poorly damped oscillations pose threats to the stability and reliability of interconnected power systems. In this work, we propose a comprehensive data-driven framework for inferring the sources of forced oscillation (FO) using solely synchrophasor measurements. During normal grid operations, fast-rate ambient data are collected to recover the impulse responses in the small-signal regime, without requiring the system model. When FO events occur, the source is estimated based on the frequency domain analysis by fitting the least-squares (LS) error for the FO data using the impulse responses recovered previously. Although the proposed framework is purely data-driven, the result has been established theoretically via model-based analysis of linearized dynamics under a few realistic assumptions. Numerical validations demonstrate its applicability to realistic power systems including nonlinear, higher-order dynamics with control effects using the IEEE 68-bus system, and the 240-bus system from the IEEE-NASPI FO source location contest. The generalizability of the proposed methodology has been validated using different types of measurements and partial sensor coverage conditions.
