Metodología para determinar la distribución de corrientes de desbalance en líneas aéreas de transmisión de energía eléctrica

Abstract

Transmission lines are essential for the transfer of energy and it is imperative to generate an optimal design and select the appropriate conductors for it. To determine an adequate setup for the ground fault protection relays, it is necessary to understand the electrical parameters of a line, such as the current flowing through the conductors. Thus, the electrical research to be performed involves the analysis of the distribution of unbalanced currents such that the current which is distributed between the earth and the ground wire, and it is significant to establish the ratio that will circulate through each direction. Accordingly, this document provides two possible methods for this calculation. These methods are corroborated by four case studies via their respective simulations, operating the software Alternative Transients Program (ATP). A key consideration in this work is to note that the ground wire is a steel conductor. Therefore, its electrical characteristics vary depending on the intensity of the current; meaning it presents a variable magnetic behavior. By using the simulator, the current that circulates through the ground wire is known, and it is possible to obtain adequate impedance values with certain percentage of error for the resistance and reactance.