Original scientific paper
IMPACT OF ELECTROMAGNETIC SHIELDS ON LOCAL OVERHEATING IN TRANSFORMER TANK
Robert Sitar
; Končar - Electrical Engineering Institute
Žarko Janić
; Končar - Power Transformers Ltd., Joint Venture of Siemens & Končar
Abstract
The paper describes different influences of magnetic and electromagnetic shielding on stray flux
distribution in power transformers. The application of electromagnetic shields on the reduction of high
temperature spots in transformer tank is studied in detail by using a 3D model for a coupled
electromagnetic-thermal calculation.
The analysis of transformer models with various shapes and dimensions of electromagnetic
shields show which factors are the most important for reduction of temperature hot spots in the tank.
Proposed shielding solution should reduce the total stray loss and maximum temperature value. It is
shown that the reduction of these values is not always achieved by shielding most of the area
endangered by the stray flux from the high current leads. The choice of the shield must take into account
the surrounding component material properties and transformer lead arrangement.
Keywords
coupled calculation; electromagnetic shielding; high current leads; stray flux; transformer
Hrčak ID:
198946
URI
Publication date:
15.7.2017.
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