Metrological Significance and Reliability of On-Line Performance Metrics in PMU-based WLS State Estimation

Abstract

The ever-increasing penetration of renewable energy sources and distributed generation needs the development and deployment of more sophisticated and precise control techniques. The paradigm shift from high-rotational inertia towards inverter-connected facilities has made modern power systems subject to strongly non-stationary operating conditions. In this context, Phasor Measurement Units (PMUs) represent a promising solution, due to their measurement accuracy as well as time synchronization. The current paper further develops the concepts recently published proposing performance assessment of PMUs relying on metrics specifically defined to quantify the estimation accuracy, reporting latency and response time. Our focus is on determining the confidence interval associated to these metrics and thus derive a robust approach for their application in measurement-based network controlling efforts. The configuration of the used simulation model is detailed and the state estimation results as function of the selected measurement weighing criteria are presented, concluding as a possible application of the reliability metrics in a Weighted Least Squares (WLS) state estimation, highlighting the performance enhancement as well as the theoretical limits of the proposed approach.