The investigation of frequency response analysis for power transformers winding condition

Artyom Nazarov,Vitaliy Savelev,Dennis Frogh,N Voropai,S Senderov,H Guliev,A Michalevich

doi:10.1051/e3sconf/201913901023

Abstract

In modern electrical transmission and distribution systems, power transformers are critical components within the network. In the event that a failure occurs in service, the impact can be far reaching. The majority of mechanical deformation within power transformers is due to short circuit faults. The ageing transformer population increases the likelihood of failure so a reliable diagnostic tools required to determine the remaining life of these assets. Although, frequency response analysis (FRA) has been recently recognized as the most reliable detection tool for mechanical deformation in transformers, in the event of minor fault, the current FRA interpretation approach may not able to detect any variations between healthy and faulty FRA signatures. This paper focuses on FRA tests for power transformer and interpretation of obtained FRA signatures.

Highlights

One of the most important problems of transformer maintenance is the monitoring system and technical diagnosis development
Different types of deformations lead to changes in frequency response analysis (FRA) signature in different range
Impulse Frequency Response Analysis (IFRA) is provided by low voltage impulse given on winding (The impulse form can be rectangular or conventional or exponential)

Summary

Introduction

One of the most important problems of transformer maintenance is the monitoring system and technical diagnosis development. Lots of investigations are held to improve this technique at the moment, but from 1978 there is no general opinion how to make a conclusion about technical condition [6].The main advantage of this technique is its high sensitivity: even minor local changes of winding elements(turns, disks) result in dramatic changes on diagnosis signature [7]. Current or voltage on bushing terminals or frequency current transformers of other windings is measured.

Results

Conclusion