Numerical Overcurrent Relay: A Digitizing Element Testing Automation and Simulation Based on Wavelet Transform

TL;DR

This paper introduces an automated testing and simulation method for numerical overcurrent relays using wavelet transform to improve accuracy, reduce costs, and enhance reliability in power system protection.

Contribution

It proposes a novel combination of LabView automation and wavelet-based waveform analysis for testing relay digitizers, verified through Matlab simulations.

Findings

Wavelet transform effectively denoises and decomposes waveforms

Automation reduces testing complexity and cost

Simulation confirms improved testing accuracy

Abstract

In todays modern technology and fast growth in electrical power supply, the need for precise protection relays has become a major issue in the power distribution system. That is, to ensure a safe operation at all levels of generation, distribution, and consumer load, the power relay should perform at the highest level of accuracy. Therefore, this work will investigate the enhancement of the Overcurrent Numerical Relay in terms of the quality of digitized incoming analog current waveform prior to numerical relay decision. However, as it is an expensive process of testing the digitizing element of numerical overcurrent relay, Analog to Digital Converter, this newly proposed method of combing test automation by LabView and advanced waveform analysis algorithms by Wavelet transform will be applied to enhance the testing process, reduce data compiling complexity, and decrease cost. In addition, the testing simulation will be presented using Matlab software to verify the testing result. As a result, with a bank of filters, denoising, and decomposition structures, Wavelet transform can provide promising results in testing and verifying the accuracy of numerical relay digitizing process along with automation process to increase the possibility of improving numerical relay digitizer testing reliability with lower cost.