Amplitude comparator based algorithm for directional comparison protection of transmission lines

Abstract

A high speed directional comparison relay based on the evaluation of the locally measured deviations of the voltage and the phase shifted current from their prefault values is described in this paper. The operation of the relay depends on the power frequency components of the voltage and phase shifted current deviation signals. The direction to a fault is determined by an amplitude comparator technique which compares a discriminant value with a positive or negative threshold. Simulation studies on a three-phase power system model show that the direction to a fault is determined within the first few milliseconds following the inception of a fault. Studies over a wide range of faults and source impedance angles show that the proposed amplitude comparator technique performs better than an analogous phase comparator technique. '

Evaluation of directional relay algorithms in presence of wind turbines and fault current limiters

“…In a previous research, a DR algorithm based on polarities of VSC and CSC was proposed. In this paper, it is shown that signs of polarities of VSC and CSC are similar for backward faults and contrary for forward faults.…”

“…In a previous study, a DRs algorithm has been found on high‐frequency signals of three phase currents and voltages. According to this algorithm, upon fault occurrence is detected, wavelet transform of currents and voltages are calculated.…”

“…This paper is aimed to investigate the DRs algorithms in these situations. To do so, at first, a lot of DRs algorithms have been studied and classified in three groups including (a) time‐domain algorithms, (b) frequency‐domain algorithms, and (c) frequency‐time algorithms. Figure shows different approaches of the mentioned groups.…”

“…In first algorithms group of DR, fault direction is determined using signal analyzing in time domain. Analyzing superimposed components in time domain, correlation–function‐based algorithms, utilizing the prefault and postfault currents, algorithm based on summation of current signal multiplied by the first derivate of voltage, and utilizing the slope change of signals are some more attractive approaches in this regard. In the following, some of the advantages and disadvantages of these algorithms are presented: Amplitudes of voltage superimposed components (VSCs) and current superimposed components (CSCs) are close to zero during normal operation of power system.…”

Single-Point Methods for Location of Distortion, Unbalance, Voltage Fluctuation and Dips Sources in a Power System

“…[10-13,36,]), voltage dips (e.g. [17,19,22,25,26,[29][30][31]37,39]), occasionally also asymmetry. With the deregulation of power industry, utilities have become increasingly interested in quantifying the responsibilities for power quality problems.…”