Enhanced performance for distance relays due to series capacitors in transmission lines

Abstract

This paper presents the Prony method as a filtering technique and its implementation in distance relay algorithms. First, the distance relay model and the impact of non-filtered frequency components when using typical digital filters in the operation of the distance relay are presented. Next, an overview of transmission line series compensation and its effects in distance relay estimation during the fault period are evaluated. Then, we present a solution using Prony method as filtering technique in distance relay algorithms. Next, the proposed algorithm is evaluated in reach and operation time of the relay, and a 3D characteristic of the Mho distance relay is presented in the impedance plane to evaluate the proposed algorithm. The proposed filter is implemented as a solution to the distance relay estimation error in the apparent impedance measurement. Lastly, an actual fault event is evaluated to validate the proposed distance relay algorithm.