LTS-Based Robust Hybrid SE Integrating Correlation

The paper introduces a robust approach for hybrid power system static state estimation (SE) utilizing phasor measurement units (PMUs). The proposed PMU-based SE exploits the time and space correlation in the PMU measurements in order to provide rejection of bad measurements and improve the SE cyber security and accuracy. The SE robustness is introduced in two steps. The first step is to robustly fit multichannel or vector autoregressive models to adjacent PMUs. The second step replaces the classical weighted least squares algorithm with a robust regression estimator. The robustness is introduced by exploiting the least trimmed squares estimator. The effectiveness of the proposed robust PMU-based SE is assessed based on Monte Carlo simulations and compared with other existing robust SE methods. A theoretical analysis is provided to explain the improvement by higher PMU sampling rates and longer periods of SE.