A Dynamic Response Recovery Framework Using Ambient Synchrophasor Data

—Wide-area dynamic studies are of paramount im- portance to ensure the stability and reliability of power grids. Recent deployments of synchrophasor technology have rendered data-driven modeling possible by analyzing fast-rate dynamic measurements. This paper puts forth a comprehensive framework for inferring the dynamic responses of the power system in the small-signal regime using ubiquitous ambient data collected during normal grid operations. We have shown that the impulse response between any pair of locations can be recovered within a scaling ambiguity in a model-free fashion by simply cross-correlating synchrophasor data streams collected only at those two locations. The result has been established via model-based analysis of linearized second-order swing dynamics under certain conditions. Nevertheless, numerical tests demonstrate that this novel data-driven approach is applicable to realistic power system models including nonlinear higher-order dynamics and controller effects. Its practical value is corroborated by excellent recovery performance attained in the WSCC 9-bus system and a synthetic 2000-bus Texas system.