A numerical method to calculate winding temperature distribution for oil immersed transformers

Winding temperature distribution is an important characteristic to describe the thermal performance of oil-immersed power transformer. In this paper an alternative numerical approach based on Finite Volume Method (FVM) has been employed to resolve the control equations of flow and heat transfer process in oil immersed power transformer, which in turn to simulate the winding temperature distribution. Moreover, we applied this numerical method to a 100kVA/5kV prototype transformer, the numerical calculated results of winding temperature distribution shows a good consistence with the experiment results. Furthermore, we have also found some flow rolls appeared between the winding top and oil outlets, these complex fluid flow may resulted from the thermal buoyancy within transformer. Thus, this presented numerical method can not only simulate the fluid distribution within power transformer but also calculate winding temperature distribution.