Analysis of positive and negative sequence parameters of overhead power lines over transient phases caused by short-circuits

Detecting defects in transmission and distribution networks of electricity needs to be analyzed solving transient regimes. The complexity of electrical circuits associated to power grids requires the use of numerical methods for transient analysis. This paper uses PSpice program for analyzing transient faults caused by three phase short-circuits. Because a three-phase short circuit is symmetrical, the power line parameters that occur in the transient analysis are the ones of positive and negative sequence. The paper analyzes 14 different cases, considering some lengths of the line until the fault point (5 km, 10 km, 20 km) and several initial phases of the tension of the R phase, at the time when the short-circuit is produced. The paper presents a virtual electric power subsystem, designed and developed by the authors, which allows numerical analysis of transients regimes caused by faults.