Study of the acceptable DC current limit in core-form power transformers

Author

Picher, P. ; Bolduc, L. ; Dutil, A. ; Pham, V.Q.

Author_Institution

Inst. de Recherche, IREQ, Varennes, Que., Canada

Volume

12

Issue

1

fYear

1997

fDate

1/1/1997 12:00:00 AM

Firstpage

257

Lastpage

265

Abstract

The temperature rise in power transformers subjected to a DC source of excitation was measured on core-form single-phase 735 kV autotransformers rated 370 MVA and 550 MVA. The measurements were compared to the temperature rise values obtained on the same transformers operating in overexcitation at 1.95 T. The results show that the tie plates of this particular type of transformer are the components most susceptible to rapid temperature rise. Smaller-scale tests on 100 kVA transformers were performed to take a specific look at these tie plates under the effect of a temperature increase. Finite-element simulations combined with analytical studies of temperature rise were performed in an attempt to determine a tolerable DC current limit based on permissible temperature standards

Keywords

autotransformers; finite element analysis; power transformer testing; power transformers; temperature distribution; temperature measurement; thermal analysis; transformer cores; 1.95 T; 100 kVA; 370 MVA; 550 MVA; 735 kV; UHV; acceptable DC current limit; autotransformers; core-form power transformers; finite-element simulations; overexcitation; permissible temperature standards; temperature rise; thermal testing; tie plates; Analytical models; Finite element methods; Particle measurements; Performance analysis; Performance evaluation; Power measurement; Power transformers; Temperature; Testing; Transformer cores;

fLanguage

English

Journal_Title

Power Delivery, IEEE Transactions on

Publisher

ieee

ISSN

0885-8977

Type

jour

DOI

10.1109/61.568248

Filename

568248