Impact of PMU Technology in State Estimation

Abstract

Recent blackouts and the need to manage larger and larger power systems closer to their stability limits are driving electricity utilities to deploy synchronized phasor measurements (PMU) for wide area monitoring and control. At the same time, modern TSOs need accurate, fast and reliable estimation of their networks' real-time conditions. State Estimator (SE), a fundamental function in dispatching control centers, is expected to perform reliably around the clock since it provides the foundation for subsequent critical security analyses, market revenue calculations, etc. PMU technology provides accurate, satellite-synchronized measurements of both magnitude and angle, which naturally fit in the SE algorithm and enhance its robustness and the quality of the results. This paper presents current results of ongoing experiences with electric utilities on the usage of PMU data in state estimation. It focuses on practical implementation aspects, such as data communication and interfacing to the control center EMS, metrics for evaluation of State Estimator results and improvements in state estimation behavior and results thanks to PMU data.