Comparação entre métodos para detecção e localização da área de falta de alta impedância em sistemas de distribuição

Abstract

The detection and localization of faults in power systems are issues of great importance for both electric companies and for consumers, mainly because of safety and costs. Therefore it deserves research advances. This paper analyzes some methods of detection and area location of single-phase high impedance faults (HIFs) in distribution systems, comparing simulation results of each method. The compared methods are Zero Sequence Differential Protection (ZSDP), Zero Sequence Quasi Differential Protection (ZSQDP), Operational Plan using RMS values (OP-RMS), Operational Plan using complex values (OP-Complex), ABC Alpha Plan, Zero Sequence Alpha Plan, and ZSDP Complex Plan. ZSDP and ZSQDP apply differential protection fundamental principles in zero sequence currents to detect and locate HIFs. While SZDP uses phasor measurements of zero sequence currents, ZSQDP uses non-phasor measurements. OP-RMS and OP-Complex methods use the operational plan, which is a technique to present the trip chart of differential protections. As in ZSDP and ZSQDP, OP-RMS uses RMS measurements and OP-Complex uses complex measures. A contribution of the paper is to use zero sequence operational plane to detect HIFs. The alpha plane is a complex plane used to represent the tripping process of differential protections. ABC Alpha Plane applies alpha plane theory in phase coordinates whereas Zero Sequence Alpha Plane uses measurements in zero sequence components. Both use phasor measurements. Although the alpha plane is consolidated in the transmission systems, the present work proposes the use of alpha plan in distribution systems. ZSDP Complex Plane is a combination of ZSDP and alpha plane methods and it is proposed in this paper. Simulations were performed in the IEEE13 bus system using PSCAD/EMTDC® and Matlab® softwares in order to endorse the detection efficiency of these methods for detecting failures in different locations, considering several distribution systems’ equipment. The impact of equipment and typical conditions of distribution systems on the analyzed methods is a contribution of this work.