Package transformer is an important equipment for energy transfer in wind farm. Aiming at three cases of package transformer core heating faults occurring continuously in a wind farm

oil analysis and disintegration of the fault transformer are carried out

and the fault points causing the heating are found. In order to analyze the mechanism of the fault

the eddy current field analysis model is established by using finite element analysis software ANSYS MAXWELL to analyze the change.Quantitative calculation is carried out for the heating condition of the winding and core. Through the analysis

it is determined that there are defects in the manufacturing process of package transformer

and the reason of heating failure is that the low-voltage winding at the head contacts too closely with the iron core.