Premature failure detection of distribution transformer with unbalanced harmonic loads using hotspot temperature analysis
Harmonics distortion is the most prominent power quality problem in an electrical power distribution network that interrupts a good quality of electric power to be drawn in the network. Additionally, the major impact of harmonics distortion is the risk of the distribution transformer failure due to...
Saved in:
Main Author:  

Format:  Thesis 
Language:  English 
Published: 
2022

Subjects:  
Online Access:  http://eprints.utm.my/id/eprint/101609/1/ZarisIzzatiMohdPSKE2022.pdf 
Tags: 
Add Tag
No Tags, Be the first to tag this record!

id 
myutmep.101609 

record_format 
uketd_dc 
spelling 
myutmep.10160920230703T02:02:01Z Premature failure detection of distribution transformer with unbalanced harmonic loads using hotspot temperature analysis 2022 Mohd. Yassin, Zaris Izzati TK Electrical engineering. Electronics Nuclear engineering Harmonics distortion is the most prominent power quality problem in an electrical power distribution network that interrupts a good quality of electric power to be drawn in the network. Additionally, the major impact of harmonics distortion is the risk of the distribution transformer failure due to the elevation of power losses and hotspot temperature (HST) in its threephase low voltage (LV) winding cables. The major challenge is to identify the exact location and point where the premature failure could occur on the threephase cables. This research proposes an HST mathematical expression to detect a premature failure at the threephase LV winding along with the transformer loading. As most transformer failure cases were rooted in heat losses that require meticulous analysis, the best accuracy numerical method as Finite Element Method (FEM) is selected to analyse the HST of the thermal distribution transformer model. The HST is simulated by considering the threephase unbalanced harmonic loads from three different group levels of THDI and under five different insulation temperature classes system. The simulation outputs are then verified with HST results from the HST mathematical model based on IEEE C57.1102018 standard. Further analysis of the simulation results has been done to propose the HST mathematical expression, which will be assessed on the threephase LV winding cables to detect premature failure. At the end of this research, it is found that the individual harmonic currents from the 7th until 19th order are the prominent harmonic orders that had exceeded the limit of MS 1555 (IEC 6100034) standard. Other than that, based on the proposed HST mathematical expression, it is found out that if the transformer is being loaded with loading over 0.9 pu, the premature failure is expected to occur promptly in the group of THDI peaklevel, prominently at 180, 200 and 220 insulation temperature classes. As for the lifetime expectancy of the distribution transformer, if the transformer is loaded with loading at 0.9 pu and above, the lifetime is approximated to drop by the minimum at 14.5% and maximum at 56% from its expectancy lifetime. Plus, it is also concluded that the possibility of the lifetime reduction to be happened at the premature failure point at average of 93.5%, 85.4% and 78% of the THDI peaklevel, THDI averagelevel and THDI lowlevel correspondingly. Hence, the findings have successfully shown the proposed method's effectiveness in vividly viewing the distribution transformer's current condition. Upon the early detection of the premature failure on the threephase cables, the execution of the proposed HST mathematical expression is also able to identify the exact location and point where the premature failure shall happen. Thus, it outright protects the distribution transformer from any unwanted breakdown, next preserves its best performance and lifetime expectancy. 2022 Thesis http://eprints.utm.my/id/eprint/101609/ http://eprints.utm.my/id/eprint/101609/1/ZarisIzzatiMohdPSKE2022.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:149137 phd doctoral Universiti Teknologi Malaysia, Faculty of Engineering  School of Electrical Engineering Faculty of Engineering  School of Electrical Engineering 
institution 
Universiti Teknologi Malaysia 
collection 
UTM Institutional Repository 
language 
English 
topic 
TK Electrical engineering Electronics Nuclear engineering 
spellingShingle 
TK Electrical engineering Electronics Nuclear engineering Mohd. Yassin, Zaris Izzati Premature failure detection of distribution transformer with unbalanced harmonic loads using hotspot temperature analysis 
description 
Harmonics distortion is the most prominent power quality problem in an electrical power distribution network that interrupts a good quality of electric power to be drawn in the network. Additionally, the major impact of harmonics distortion is the risk of the distribution transformer failure due to the elevation of power losses and hotspot temperature (HST) in its threephase low voltage (LV) winding cables. The major challenge is to identify the exact location and point where the premature failure could occur on the threephase cables. This research proposes an HST mathematical expression to detect a premature failure at the threephase LV winding along with the transformer loading. As most transformer failure cases were rooted in heat losses that require meticulous analysis, the best accuracy numerical method as Finite Element Method (FEM) is selected to analyse the HST of the thermal distribution transformer model. The HST is simulated by considering the threephase unbalanced harmonic loads from three different group levels of THDI and under five different insulation temperature classes system. The simulation outputs are then verified with HST results from the HST mathematical model based on IEEE C57.1102018 standard. Further analysis of the simulation results has been done to propose the HST mathematical expression, which will be assessed on the threephase LV winding cables to detect premature failure. At the end of this research, it is found that the individual harmonic currents from the 7th until 19th order are the prominent harmonic orders that had exceeded the limit of MS 1555 (IEC 6100034) standard. Other than that, based on the proposed HST mathematical expression, it is found out that if the transformer is being loaded with loading over 0.9 pu, the premature failure is expected to occur promptly in the group of THDI peaklevel, prominently at 180, 200 and 220 insulation temperature classes. As for the lifetime expectancy of the distribution transformer, if the transformer is loaded with loading at 0.9 pu and above, the lifetime is approximated to drop by the minimum at 14.5% and maximum at 56% from its expectancy lifetime. Plus, it is also concluded that the possibility of the lifetime reduction to be happened at the premature failure point at average of 93.5%, 85.4% and 78% of the THDI peaklevel, THDI averagelevel and THDI lowlevel correspondingly. Hence, the findings have successfully shown the proposed method's effectiveness in vividly viewing the distribution transformer's current condition. Upon the early detection of the premature failure on the threephase cables, the execution of the proposed HST mathematical expression is also able to identify the exact location and point where the premature failure shall happen. Thus, it outright protects the distribution transformer from any unwanted breakdown, next preserves its best performance and lifetime expectancy. 
format 
Thesis 
qualification_name 
Doctor of Philosophy (PhD.) 
qualification_level 
Doctorate 
author 
Mohd. Yassin, Zaris Izzati 
author_facet 
Mohd. Yassin, Zaris Izzati 
author_sort 
Mohd. Yassin, Zaris Izzati 
title 
Premature failure detection of distribution transformer with unbalanced harmonic loads using hotspot temperature analysis 
title_short 
Premature failure detection of distribution transformer with unbalanced harmonic loads using hotspot temperature analysis 
title_full 
Premature failure detection of distribution transformer with unbalanced harmonic loads using hotspot temperature analysis 
title_fullStr 
Premature failure detection of distribution transformer with unbalanced harmonic loads using hotspot temperature analysis 
title_full_unstemmed 
Premature failure detection of distribution transformer with unbalanced harmonic loads using hotspot temperature analysis 
title_sort 
premature failure detection of distribution transformer with unbalanced harmonic loads using hotspot temperature analysis 
granting_institution 
Universiti Teknologi Malaysia, Faculty of Engineering  School of Electrical Engineering 
granting_department 
Faculty of Engineering  School of Electrical Engineering 
publishDate 
2022 
url 
http://eprints.utm.my/id/eprint/101609/1/ZarisIzzatiMohdPSKE2022.pdf 
_version_ 
1776100737393098752 