A Novel Principle of Current Differential Protection for UHV and EHV Transmission Lines Based on Distributed Parameters Line Model

Abstract

Distributed capacitive current of ultra high voltage and extra high voltage (UHV&EHV) transmission lines has a severe negative effect on current differential protection. The current differential protection in this proposed paper is based on distributed parameters line model of the transmission line and has been used to solve the problem of distributive capacitive current of transmission line. Time-domain algorithm has been used to calculate currents at the set point of the line by using both ends current. By adding linear interpolation with low computational rate at each sampling points has been achieved. The theoretical analysis of this method is broach to demonstrate how the novel principle is of high sensitivity in differentiating between the external and the internal faults of the line. After theoretical analysis and applying the pristine novel principle of current differential protection for UHV and EHV transmission lines based on distributed parameters line model, the simulation results illustrates that the analysis done in this paper is quite appropriate as desired, correspondingly this recently acquired principle is much reliable, compared to the traditional principle.