Real-time State Estimation in a System Partially Observed by PMUs: A Coherency Data Mining Based Approach

D. GRACIELA COLOMÉ; C. REHTANZ; GABRIEL ORTIZ

Perth

Congreso; 2019 9th International Conference on Power and Energy Systems (ICPES 2019),; 2019

ICPES

In this paper a real-time state estimator is proposed. The algorithm involves two stages: the first one runs at SCADA speed and is based on a static state estimator (SSE) with measurements from remote terminal units (RTUs) and phasor measurement units (PMUs). The second stage runs at PMU speed and is based on a linear state estimator (LSE) that uses only measurements from PMUs. It is assumed that in stage two the system is partially observed by PMUs. In order to compensate the lack of measurements and ensure the observability of the entire system a novel methodology that generates voltage dynamic pseudo-measurements is developed. This methodology is based on the concept of dynamic coherency of an electric power system (EPS). The state estimation algorithm together with the methodology to generate pseudo-measurements have been evaluated on the New England system under several operating scenarios. Results show the ability of the algorithm to accurately estimate the state in real time in the presence of both slow and fast transient phenomena.