Determination of local losses and temperatures in power transformer tank

Paper presents research of local losses and temperature rise in transformer steel tank. First experimental method based on initial rate is presented. This a direct for determining distribution structural parts. Technique relies the fact that after body has settled at steady state internal heat source suddenly removed or applied, change any point proportional to input (loss density) point. To test applicability sensors instrument loss measurement method, system was tested conductors (strips) magnetic rings. Second part work consisted investigations model tank overheating. The excitation windings were sources field. Existence three separate gave possibility value position field inside Local evaluated by proposed temperature. Heat-run tests made temperatures measured. Measured used transfer coefficients – oil interface. It concluded can be presented as function flux from oil. Finally, calculated finite element method. Losses electromagnetic calculation represented thermal numerical model. Heat equations solved solid domain (tank) while cooling conditions defined checked experimentally. Calculated compared measured good agreement.