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A precise measurement method of stray?field loss in structural parts of power transformers is proposed. The leakage flux distribution of no?load condition can be commendably compensated as load condition by introdu?cing two compensatory coils. Difference of coil losses in no?load condition and load condition can be reduced, which is a problem in the traditional measurement method. By this method the loss of the structure can be measured more accurately. The stray?field loss of two kinds of magnetic shielding and magnetic steel in different exciting cur?rents were measured and calculated in this paper. The distribution of the silicon sheets along the laminated direction was investigated, which is very useful for simulation engineer to optimize simulation modeling. By comparing the measured and calculated results, the proposed methods are validated. And the proposed method can be used to ver?ify the validity of the calculation method of the electromagnetic field and the loss under different conditions.
The impulse voltage distribution of HV winding and the transfer overvoltage of LV winding of typical power transformer are calculated and analyzed. The influence of unit number of LV winding to transfer overvoltage is researched.
