A Hybrid Power System State Estimator Under Limited PMU Availability

This paper proposes an equality-constrained hybrid state estimation algorithm that processes data from the supervisory control and data acquisition (SCADA) and wide area monitoring systems. The devised method is founded upon the widely accepted weighted least squares approach and is viable in single- and multi-stage architectures. The main advantage of this method is found in its non-intrusive implementation, that is, keeping the core functions of conventional state estimation software intact in the energy management system, while improving the quality of the conventional SCADA-based estimators. Following a detailed description of the derivation of the proposed approach and its alternative formulations, numerical simulations on the IEEE 14-, 118-, and 300-bus benchmark systems are conducted to assess its performance. The proposed estimation scheme is found to outperform similar methods found in recent literature with respect to various performance metrics.