Page 23 - ECLECTIC MARCH-2022 INSIDE PAGES_p2.indd
P. 23
E STUDY ON THE REPETITIVE FAULT IN
A 50 MVA POWER TRANSFORMER
SUBHAYAN MUKHERJEE, SUBIR GANGOPADHYAY
SUBSTATIONS DEPARTMENT
Abstract
This paper covers the experience of Substations Department in dealing with the repetitive fault in a power
transformer and corresponding rectification jobs. During the repair work of the transformer, all the vital
costly components were dismantled, checked and tested thoroughly at site. Along with that after replacing the
damaged components the whole unit of the On Load Tap Changer was reassembled and finally the transformer
could be put into load after satisfactory testing being carried out for it.
This paper deals with the struggle and challenges, faced by the maintenance team for analyzing the actual root
cause of failure and thereby carrying out subsequent course of action. It also deals with the struggle, faced by
the maintenance team while carrying out maintenance activities during the scorching heat of the peak summer
in the city. Along with that continuous pressure was there for the maintenance team to readily recommission
the power transformer as quickly as possible since it was di cult to manage the load for the station due to
the outage.
INTRODUCTION that it was really a very critical repair work and globally,
very few utilities have the ability to carry out this job
In CESC, among all the assets, power transformer is one successfully at site, without any help from OEM. Details of
of the costliest and vital asset and so special care needs the fault analysis and repair work will be discussed later
to be taken in order to maintain it properly and rectify in the paper.
the faults without any delay. Presently, in CESC system,
there are total 267 nos. of Power Transformers operating Plant Specification
at various voltage levels.
Equipment Name: Majerhat S/S T-3
DETAILS OF CASE STUDY Rated Capacity: 50 MVA
Rated Voltage Ratio: 132/34.5 kV
50 MVA T3 at Majerhat S/S got tripped thrice during Rated Current: 218.7 A (HV) / 837 A (LV)
the period 18/05/2019 to 05/06/2019 due to some Make: BHEL
component failure inside OLTC. After detailed and Year of Manufacture: 1984
thorough investigation of the problems in stages, Type of OLTC: Easun MR (M type) – In Tank design
the transformer has been successfully put on load on No. of Tap Positions: 15 (without reversing switch)
05/06/2019 at a fixed tap. It can be stated undoubtedly
23
A 50 MVA POWER TRANSFORMER
SUBHAYAN MUKHERJEE, SUBIR GANGOPADHYAY
SUBSTATIONS DEPARTMENT
Abstract
This paper covers the experience of Substations Department in dealing with the repetitive fault in a power
transformer and corresponding rectification jobs. During the repair work of the transformer, all the vital
costly components were dismantled, checked and tested thoroughly at site. Along with that after replacing the
damaged components the whole unit of the On Load Tap Changer was reassembled and finally the transformer
could be put into load after satisfactory testing being carried out for it.
This paper deals with the struggle and challenges, faced by the maintenance team for analyzing the actual root
cause of failure and thereby carrying out subsequent course of action. It also deals with the struggle, faced by
the maintenance team while carrying out maintenance activities during the scorching heat of the peak summer
in the city. Along with that continuous pressure was there for the maintenance team to readily recommission
the power transformer as quickly as possible since it was di cult to manage the load for the station due to
the outage.
INTRODUCTION that it was really a very critical repair work and globally,
very few utilities have the ability to carry out this job
In CESC, among all the assets, power transformer is one successfully at site, without any help from OEM. Details of
of the costliest and vital asset and so special care needs the fault analysis and repair work will be discussed later
to be taken in order to maintain it properly and rectify in the paper.
the faults without any delay. Presently, in CESC system,
there are total 267 nos. of Power Transformers operating Plant Specification
at various voltage levels.
Equipment Name: Majerhat S/S T-3
DETAILS OF CASE STUDY Rated Capacity: 50 MVA
Rated Voltage Ratio: 132/34.5 kV
50 MVA T3 at Majerhat S/S got tripped thrice during Rated Current: 218.7 A (HV) / 837 A (LV)
the period 18/05/2019 to 05/06/2019 due to some Make: BHEL
component failure inside OLTC. After detailed and Year of Manufacture: 1984
thorough investigation of the problems in stages, Type of OLTC: Easun MR (M type) – In Tank design
the transformer has been successfully put on load on No. of Tap Positions: 15 (without reversing switch)
05/06/2019 at a fixed tap. It can be stated undoubtedly
23
