Estimação de estados no sistema interligado nacional: uma abordagem considerando medições SCADA e PMUs

Abstract

This work aims to use the Weighted Least Squares Method (WLS) applied to State Estimation for monitoring the National Interconnected System (SIN). In the proposed methodology, two different data sources are used: traditional measurements from a SCADA system (Supervision and Data Acquisition System) and synchronized phasor measurements from PMUs (Phasor Measurement Unit). It is expected that the sources used together provide greater robustness to the state estimator and help in determining the most probable state of operation of a power system to be supervised. The different simulations scenarios serve to identify the configuration of meters that culminate in smaller estimation errors of voltage values (magnitude and angle) of the system buses. The first scenario has only SCADA in operation, the second consists of SCADA with the substitution of 4 traditional measurements by new PMU technology, and finally, the third scenario consisting of SCADA with redundancy of PMU measurements, that is, besides traditional measurements, there is an additional number of PMUs. All scenarios were validated using the Monte Carlo Method in order to evaluate the results in a statically reliable way. The simulations were carried out computationally in python programming language using the Brazilian 107-bus test system, which represents the SIN, through pandapower library. The results were satisfactory, culminating in average errors of less than 2% and reaffirm that the advent of synchronized phasor measurement units can contribute immensely to the accuracy of the estimated values related to the operating state of the electrical network.