Robust WLS estimator using reweighting techniques for electric energy systems

•A state estimator based on a weighted least squares model is proposed which is robust against outliers.•The RWLS method considers measurement dependencies and its weights are automatically readjusted.•Two realistic systems are studied and the results are analyzed using Design of Experiments and ANOVA techniques.

The state estimator is a key tool in the operation of any real-world electric energy system. In this paper, a state estimator based on a weighted least squares model is proposed which is robust against outliers. This algorithm presents two relevant features: robustness that is achieved by readjusting measurement weights, and accuracy that is attained by considering measurement dependencies. The proposed method is tested in the IEEE 57-bus and 118-bus systems and the obtained results are analyzed using Design of Experiments and ANOVA techniques.