Practical approach to testing the transformer differential protection for internal and external faults, CT saturation and inrush transients

The Journal of Engineering

Danielly C. G. Rocha¹ 

[1] Institute of Technological Sciences, Federal University of Itajubá , Itabira, MG , Brazil

关键词: current saturation;    power system;    current transformers;    simulated signals;    transformer differential protection;    testing system;    computational simulations;    external faults;    faults modes;    transformer protection relay;    numerical relay tests;    power transformer;    computational tool;    inrush transients;    alternative transient program;    programmable test;    ATP;    internal faults;   

DOI  :  10.1049/joe.2018.0274

学科分类：工程和技术（综合）

来源: IET

【 摘 要 】

This study presents a methodology that allows examining the differential protection of power transformers through computational simulations and numerical relay tests. Using that purpose, the alternative transient program (ATP) was used as a computational tool to perform several different events, which the power transformers are submitted to, and that can cause mal-operation of its differential protection, such as: external and internal faults, inrush current and saturation of current transformers (CTs). A testing system was implemented in laboratory, which consisted in simulating the power system in ATP (power transformer, CTs and faults modes) and applying the simulated signals through a programmable test set to a commercial relay to evaluate their response to these events. The main results of the behaviour of transformer protection relay under the tested transients are presented and discussed in this work.

【 授权许可】

CC BY