Adaptations to the Distance Relay Model (ANSI type 21) Available in ATPDraw to Enable the Analysis of the Dynamic Performance of this Protection in Single Pole Switching Schemes for Transmission Lines

Abstract

This paper analyzes the distance relay (ANSI type 21) dynamic performance in presence of single line to ground faults followed by single pole trip and
reclosing, applied to Electrical Power System (SEP) referred to thought adaptations to the distance relay model available in the Alternative Transients Program (ATP) software. Due to the relay model 21 available in ATP-library does not have a failed phase identifier, adjustments have been made to the model to operate in a single phase manner; the main change occurs in their comparator. The relay model developed is implemented within a primary protection scheme for one of the two transmission lines that link to two substations of the test SEP, where it is sought to analyze the dynamic performance of the relay against two different line models, a pi model; which is commonly used by programs dedicated to the configuration and coordination of protections, and a JMarti line model, which considers the nature of distributed parameters and frequency dependence. In both cases, the impedance trajectory seen by the relays 21 is analyzed and in addition, thought the development of an algorithm, the performance of the special function of distance relay called Power Swing Blocking (PSB) is simulated