Uma nova metodologia para detecção, identificação e monitoramento de fugas em linhas de transmissão utilizando PMUs

Abstract

This work presents a new methodology for detection, identification and estimation of current leakages in power transmission lines using state estimation. It is assumed that three-phase voltages and line currents are measured at the substation terminals using Phasor Measurement Units (PMUs). From the proposed methodology the transmission line is divided into sections and the towers are represented as null power injection buses for the solution of the problem. For each line section the well known PI model is used. Currents, expressed in rectangular coordinates, in all transmission line sections, are chosen as state variables to be estimated. The nodal voltages, active and reactive power injections are calculated by using the Kirchhoff laws. The detection and identification of the location of existing leakage currents at the transmission towers can be determined by using the proposed methodology. To achieve this, the methodology makes use of concepts like power flow, synchronized phasor monitoring systems, state estimation and optimization problem modeling. State estimator optimization problems are solved using the interior point method with the modified safety barrier, in which one of its applications is the nonlinear problems solving with inequality constraints. A brazilian transmission line data was used in this work to get a situation close to a real case. Tests were carried out considering variations in the location and type of the leakage, in addition to different operating conditions of the transmission line and different values of errors associated with the measurement system, showing potential for development in real applications.