Open AccessDifferential protection in power transformers using the statistical second central moment
Author(s) -
Esponda Hernandez Hector,
Vázquez Martínez Ernesto,
Andrade Soto Manuel Antonio
Publication year - 2018
Publication title -
the journal of engineering
Language(s) - English
Resource type - Journals
ISSN - 2051-3305
DOI - 10.1049/joe.2018.0234
Subject(s) - inrush current , differential protection , waveform , matlab , computer science , transient (computer programming) , transformer , current transformer , electronic engineering , control theory (sociology) , filter (signal processing) , algorithm , electrical engineering , engineering , telecommunications , voltage , artificial intelligence , radar , control (management) , computer vision , operating system
This study describes a new differential protection algorithm for power transformers, which is not affected by transient conditions. The proposed algorithm uses the statistical second central moment, statistical variance, to characterise the signal waveform. The goal is to obtain the variance from each differential current after a pre‐processing filter stage and to compare it with a threshold. The event will be identified as an internal fault, or otherwise as an inrush current. The algorithm was implemented in MATLAB, and a broad array of cases was carried out using the electromagnetic transient software PSCAD. All results show the algorithm successfully differentiated inrush from the internal fault conditions in over 2000 cases.