Transformer is the key equipment in power system. For mastering the loss and temperature rise of transformer during operation

a three-dimensional multi-physics coupled finite element model is set up in this paper to simulate the distribution of the loss and temperature rise of each part of the transformer. Firstly

the traditional Bertotti loss separation model is corrected in accordance with various loss principles of the transformer core

the total loss of the transformer core is calculated

and the calculation formula of the loss of oil tank and structural parts is derived from this. Then

based on the geometric characteristics of the winding

the calculation method of each component of the winding loss is analyzed

and the field-circuit coupling method is used to simulate the loss distribution of each part of the transformer. Finally

the knowledge of heat transfer is used to analyze the specific process of natural heat transfer of oil-immersed transformer

and such two physical fields as heat transfer and laminar flow design are performed. Moreover

the temperature distribution of various internal part inside the transformer is simulated and calculated through non-isothermal flow multi-physical field coupling.