Impacto da Hipótese de Independência dos Erros no Processo de Estimação de Estado

Abstract

The state estimation process is fundamental for the real-time operation of electric power systems (EPSs), since the estimated values of the state variables are the basis for the execution of functions related to real-time monitoring of EPSs. In the traditional modeling of the state estimation process in EPSs, it is assumed the hypothesis that the measurements available for estimation have independent random errors. However, because the measurements are the result of processing signals from several sensors, and several measurements may share signals from the same sensors, that hypothesis is not valid. Given the above, this paper has two objectives: (i) to analyze the procedure for obtaining measurements from sensor signals; and (ii) to investigate the influence of the sharing of sensor signals in the traditional process of state estimation in EPSs. For this, this study uses the weighted least squares state estimator, associated with the largest normalized residual test, as they are the estimator and the technique for gross errors processing most used in practice and most studied in academia.The influence of the hypothesis that the measurement errors are independent was evaluated from the perspective of the accuracy of the estimates obtained and the handling of gross errors.