The Study On Temperature Rise Of Natural Oil Circulation Power Transformer With Pannel-Type Radiator

Oil immersed transformer is widely used in power transmission because of its good coolant, low wastage and price, large capacity. And about 80% of these transformers use natural oil circulation.More and more large power transformers used to using by pump and fan are cooling by ONAN for economy and environment protecting. The calculation method using in factory has larger error and isn't used in high ignition point oil transformer.In this paper a calculation method, which has been verified by experiment results, is presented based on the fundamental theories and rule equation of heat transfer to calculate the temperature rise of average oil, top oil, coil, core and hot-point. A program has been compiled. The program is the same with ONAN and ONAF. The temperature rise of high ignition point oil transformer also use the program. Some factors are analysed to influence temperature rise of transformer.