Transformer differential protection method based on the comprehensive braking criterion

Authors

Mei LI, School of Electronic Information and Electrical Engineering, Anhui University of Science and Technology, Huainan 232001 , China
Jusheng TANG, School of Electronic Information and Electrical Engineering, Anhui University of Science and Technology, Huainan 232001 , China

Keywords

transformer differential protection, discrimination phase difference, comprehensive braking criterion, inrush current, MATLAB/Simulink

Abstract

The key problem of transformer differential protection method is the method to distinguish the inrush current from short circuit current in order to prevent misoperation. The traditional method based on two harmonics amplitude ratios has a single criterion and insufficient accuracy, and thus it may cause a misoperation in some conditions. On this background, the method of phase difference discrimination is improved, and the braking ratio is utilized to set up a comprehensive braking criterion. Simulation modules are modeled in Matlab/Simulink and the transformer is simulated and checked under different operating conditions. It is shown that the criterion not only distinguish short circuit faults in different situations, but also recognize inrush currents effectively, and make corresponding protection actions for different fault types of transformers.

DOI

10.19781/j.issn.16739140.2020.02.018

First Page

135

Last Page

141

Recommended Citation

LI, Mei and TANG, Jusheng (2020) "Transformer differential protection method based on the comprehensive braking criterion," Journal of Electric Power Science and Technology: Vol. 35: Iss. 2, Article 18.
DOI: 10.19781/j.issn.16739140.2020.02.018
Available at: https://jepst.researchcommons.org/journal/vol35/iss2/18