Electric Distribution System Fault Location Considering Shunt Capacitances

Abstract

This article presents novel fault-location algorithms for distribution systems by utilizing voltage and current measurements at the local substation. The methods extend from previously published algorithms by explicitly modeling feeder shunt capacitances so that the methods will be applicable to distribution feeders with significant capacitances, such as underground cables. The bus impedance matrix technique is harnessed to develop the relationship between the substation voltage and current and the fault location and fault resistances, based on which the fault location can be derived. To accommodate inherent unbalances in distribution systems, the methods are developed in the phase domain instead of the symmetrical component domain. The distribution network parameters and topology are assumed to be known for constructing the bus impedance matrix. Simulation studies have demonstrated that the methods can achieve very accurate results.

Keywords:

• fault location
• fault analysis
• power system protection