Title :
Thermal model of a disk coil with directed oil flow
Author :
Del Vecchio, Robert M. ; Feghali, Pierre
Author_Institution :
North American Transformer, Milpitas, CA, USA
Abstract :
A model of a transformer disk coil with directed oil flow is presented which utilizes a network of oil flow paths. Along each path segment, oil velocities and temperature rises are computed. The oil flow is assumed to be thermally driven. The model includes temperature dependent oil viscosity, resistivity, oil density, and temperature and velocity dependent heat transfer and friction coefficients. Because of the nonlinearities, an iterative solution is necessary. Temperature and oil velocity profiles are computed. From this, the average winding rise and the hot spot temperature can be determined. The model can also be used for optimal positioning of the oil flow washers
Keywords :
coils; electrical resistivity; heat transfer; iterative methods; power transformer insulation; thermal analysis; transformer oil; transformer windings; viscosity; average winding rise; average winding temperature; directed oil flow; disk coil; friction coefficients; hot spot temperature; iterative solution; nonlinearities; oil density; oil flow paths network; oil flow washers positioning; oil velocities; optimal positioning; resistivity; temperature dependent oil viscosity; temperature rises; thermal model; thermally driven oil flow; transformer; velocity dependent heat transfer; Coils; Drives; Ducts; Friction; Heat transfer; Hydraulic diameter; Oil insulation; Petroleum; Temperature dependence; USA Councils;
Conference_Titel :
Transmission and Distribution Conference, 1999 IEEE
Conference_Location :
New Orleans, LA
Print_ISBN :
0-7803-5515-6
DOI :
10.1109/TDC.1999.756171
