The winding deformation accidents caused by external short-circuit faults have become an urgent problem to be solved for the safety of power system, and the key to solve that is calculating short-circuit electromagnetic force accurately. Numerous studies about influence factors of electromagnetic force distribution characteristics have been carried out. The influence of the imbalance of ampere-turns, the asymmetry of winding height, the insertion of tap windings, and the winding transposition structure on the electromagnetic force distribution are obtained. However, the influence of winding radius deviation which occurs inevitably during the manufacture process haven’t been consider in the calculation model. In this paper, based on the parameters of a 110kV transformer with high failure rate, the influence of winding radius deviation on the electromagnetic force distribution were studied. First of all, the distribution function of winding radius deviation, which confirms the normal distribution, was obtained by curve fitting analysis of measured data. Then, a 2D FEM transformer model considering the winding radius deviation was established. Through steady-state magnetic field calculation, the electromagnetic force distribution characteristics under the influence of radius deviation was obtained: a fluctuation phenomenon occurs among radial electromagnetic force axial distribution when considering the winding radius deviation. Under the actual statistical distribution N(0.61,1.222), the maximum fluctuation ratio is about 26%. At the meantime, the fluctuation of radial electromagnetic force along axial direction increases with the expectation and standard deviation increasing. Those results provide a reference for process control of transformer manufacturing.

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