Does anyone have any references that explain the mechanical forces which develop in a transformer during an external fault? I'm looking for something that can at least qualitatively explain the fundamentals. None of my own references seem to cover this topic and I've pretty much struck out with online searches.
Mechanical forces in a transformer
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Silent Guardian
That is darn interesting. Share with us when you find out.
G
Guest
Does this work??
Accession number: 9441348
Title: Investigation of transformer electromagnetic forces caused by external faults using FEM
Authors: de Azevedo, A.C.1 ; Rezende, I.1 ; Delaiba, A.C.1 ; de Oliveira, J.C.1 ; Carvalho, B.C.; de Bronzeado, H.S.
Author affiliation: 1 Fac. of Electr. Eng., Fed. Univ. of Uberlandia, Brazil
Source: 2006 IEEE/PES Transmission & Distribution Conference & Exposition: Latin America (IEEE Cat. No. 06EX1340)
Publication date: 2006
Pages: 6 pp.
Language: English
ISBN-10: 1 4244 0287 5
Document type: Conference article (CA)
Conference name: 2006 IEEE/PES Transmission & Distribution Conference & Exposition: Latin America
Conference date: 15-18 Aug. 2006
Conference location: Caracas, Venezuela
Sponsor: IEEE Power Eng. Soc
Publisher: IEEE
Place of publication: Piscataway, NJ, USA
Material Identity Number: XX2007-00409
Abstract: This paper is focused on the investigation of transformers internal electromagnetic forces caused by external fault. The simulations are based on the finite elements method (FEM) to model a three-phase transformer and also to calculate the forces via traditional mechanical and electrical equations. Normal operation and symmetrical fault conditions are used for the estimation of internal radial and axial forces. This work, which leads to specific transformer performances, allows to verify the potentiality of the method used and also the physical consistence of the computational simulations. The results shown in this paper are flux distribution, losses and other information regarding the equipment operation. The FEM approach has shown to be a powerful tool on the estimation of mechanical stress within transformers and it can be quite useful at the design stage of such devices
Number of references: 7
Inspec controlled terms: electromagnetic forces - fault diagnosis - finite element analysis - power transformers
Uncontrolled terms: transformer electromagnetic forces - finite elements method - mechanical-electrical equations - symmetrical fault conditions - computational simulations - flux distribution - FEM approach - mechanical stress estimation
Inspec classification codes: B8350 Transformers and reactors - B0290T Finite element analysis
Treatment: Practical (PRA); Theoretical or Mathematical (THR)
Discipline: Electrical/Electronic engineering (B)
Database: Inspec
Copyright 2007, The Institution of Engineering and Technology
JR
Accession number: 9441348
Title: Investigation of transformer electromagnetic forces caused by external faults using FEM
Authors: de Azevedo, A.C.1 ; Rezende, I.1 ; Delaiba, A.C.1 ; de Oliveira, J.C.1 ; Carvalho, B.C.; de Bronzeado, H.S.
Author affiliation: 1 Fac. of Electr. Eng., Fed. Univ. of Uberlandia, Brazil
Source: 2006 IEEE/PES Transmission & Distribution Conference & Exposition: Latin America (IEEE Cat. No. 06EX1340)
Publication date: 2006
Pages: 6 pp.
Language: English
ISBN-10: 1 4244 0287 5
Document type: Conference article (CA)
Conference name: 2006 IEEE/PES Transmission & Distribution Conference & Exposition: Latin America
Conference date: 15-18 Aug. 2006
Conference location: Caracas, Venezuela
Sponsor: IEEE Power Eng. Soc
Publisher: IEEE
Place of publication: Piscataway, NJ, USA
Material Identity Number: XX2007-00409
Abstract: This paper is focused on the investigation of transformers internal electromagnetic forces caused by external fault. The simulations are based on the finite elements method (FEM) to model a three-phase transformer and also to calculate the forces via traditional mechanical and electrical equations. Normal operation and symmetrical fault conditions are used for the estimation of internal radial and axial forces. This work, which leads to specific transformer performances, allows to verify the potentiality of the method used and also the physical consistence of the computational simulations. The results shown in this paper are flux distribution, losses and other information regarding the equipment operation. The FEM approach has shown to be a powerful tool on the estimation of mechanical stress within transformers and it can be quite useful at the design stage of such devices
Number of references: 7
Inspec controlled terms: electromagnetic forces - fault diagnosis - finite element analysis - power transformers
Uncontrolled terms: transformer electromagnetic forces - finite elements method - mechanical-electrical equations - symmetrical fault conditions - computational simulations - flux distribution - FEM approach - mechanical stress estimation
Inspec classification codes: B8350 Transformers and reactors - B0290T Finite element analysis
Treatment: Practical (PRA); Theoretical or Mathematical (THR)
Discipline: Electrical/Electronic engineering (B)
Database: Inspec
Copyright 2007, The Institution of Engineering and Technology
JR
G
Guest
One more but this looks really old and maybe not relevant. But I will post and let you decide.
JR
Accession number: 424391
Title: Electrodynamic stability of the external windings of large transformers
Authors: Zenova, V.P.1 ; Ivanova, N.S.1 ; Lur'e, S.I.1 ; Mil'man, L.I.1
Author affiliation: 1 V.I. Lenin All-Union Electrotechnical Inst., USSR
Serial title: Electric Technology USSR
Abbreviated serial title: Electr. Technol. USSR (UK)
Volume: 4
Publication date: 1971
Pages: 1-15
Language: English
ISSN: 0013-4155
CODEN: ELTGAW
Document type: Journal article (JA)
Country of publication: UK
Translation serial title: Elektrichestvo
Translation abbreviated serial title: Elektrichestvo (USSR)
Publication date: 1971
Translation pages: 1-6 no.10
Translation ISSN: 0013-5380
Translation CODEN: ELEKA3
Translation country of publication: USSR
Material Identity Number: E141-1972-003
Abstract: A computer program is proposed for evaluating the tensile stresses and strains arising in the external windings of large transformers due to radial forces in short circuit and other fault conditions having regard more particularly to the non-linearity of the mechanical characteristics of the conducting and insulating material and to the dimensions of individual elements of windings
Number of references: 10
Inspec controlled terms: computer applications - electrical engineering applications of computers - stability - transformer windings - transformers
Uncontrolled terms: electrodynamic stability - external windings - large transformers - computer program - tensile stresses - strains - radial forces - fault conditions - mechanical characteristics
Inspec classification codes: B8350 Transformers and reactors - C7410B Power engineering computing
Treatment: Applications (APP); Practical (PRA)
Discipline: Electrical/Electronic engineering (B); Computers/Control engineering ©
Database: Inspec
Copyright 1972, IEE
JR
Accession number: 424391
Title: Electrodynamic stability of the external windings of large transformers
Authors: Zenova, V.P.1 ; Ivanova, N.S.1 ; Lur'e, S.I.1 ; Mil'man, L.I.1
Author affiliation: 1 V.I. Lenin All-Union Electrotechnical Inst., USSR
Serial title: Electric Technology USSR
Abbreviated serial title: Electr. Technol. USSR (UK)
Volume: 4
Publication date: 1971
Pages: 1-15
Language: English
ISSN: 0013-4155
CODEN: ELTGAW
Document type: Journal article (JA)
Country of publication: UK
Translation serial title: Elektrichestvo
Translation abbreviated serial title: Elektrichestvo (USSR)
Publication date: 1971
Translation pages: 1-6 no.10
Translation ISSN: 0013-5380
Translation CODEN: ELEKA3
Translation country of publication: USSR
Material Identity Number: E141-1972-003
Abstract: A computer program is proposed for evaluating the tensile stresses and strains arising in the external windings of large transformers due to radial forces in short circuit and other fault conditions having regard more particularly to the non-linearity of the mechanical characteristics of the conducting and insulating material and to the dimensions of individual elements of windings
Number of references: 10
Inspec controlled terms: computer applications - electrical engineering applications of computers - stability - transformer windings - transformers
Uncontrolled terms: electrodynamic stability - external windings - large transformers - computer program - tensile stresses - strains - radial forces - fault conditions - mechanical characteristics
Inspec classification codes: B8350 Transformers and reactors - C7410B Power engineering computing
Treatment: Applications (APP); Practical (PRA)
Discipline: Electrical/Electronic engineering (B); Computers/Control engineering ©
Database: Inspec
Copyright 1972, IEE
Thanks for finding those, JR. Those papers are definitely on topic, but are more advanced than what I am looking for. They'd probably be way over my head (I vaguely remember FEM from grad school, but I've never used it since then). I'm looking for something a little more basic--but I may try to get a copy of the first paper because its citations may point to what I'm looking for.
The reason I'm looking is we've had problems with a 138/46 kV 60 MVA transfomer's sudden pressure relay tripping for an external fault. It's happened three times in the past eight years. The relay was replaced after the first operation, so it probably isn't a problem with the relay. The transformer has also been tested and doesn't show signs of any damage. The idea is that the pressure relay is operating because of the transformer's windings moving (I believe due to the Lorentz force) during the high-current external fault, and the movement of the windings causes a pressure change within the transformer tank that trips the relay. From what I've seen so far, it is not a rare problem, and ANSI C37.108 talks a little bit about how to prevent the relay from tripping, but I'd like to understand better what is actually happening (in what way the windings move and why). I'm thinking the key may be a good textbook on transformer design, but I don't happen to have one of those (my transformer references are more geared toward application rather than design). However I just had the thought that a search on "sudden pressure relay misoperation" might lead me in the right direction--I'll try that when I get a chance.
The reason I'm looking is we've had problems with a 138/46 kV 60 MVA transfomer's sudden pressure relay tripping for an external fault. It's happened three times in the past eight years. The relay was replaced after the first operation, so it probably isn't a problem with the relay. The transformer has also been tested and doesn't show signs of any damage. The idea is that the pressure relay is operating because of the transformer's windings moving (I believe due to the Lorentz force) during the high-current external fault, and the movement of the windings causes a pressure change within the transformer tank that trips the relay. From what I've seen so far, it is not a rare problem, and ANSI C37.108 talks a little bit about how to prevent the relay from tripping, but I'd like to understand better what is actually happening (in what way the windings move and why). I'm thinking the key may be a good textbook on transformer design, but I don't happen to have one of those (my transformer references are more geared toward application rather than design). However I just had the thought that a search on "sudden pressure relay misoperation" might lead me in the right direction--I'll try that when I get a chance.
G
Guest
^^^ I was just taking a stab based on those keywords you through out in the first post.
If you want me to keyword search I have access to most online engineering libraries/databases through my grad school connections
JR
If you want me to keyword search I have access to most online engineering libraries/databases through my grad school connections
JR
