Simulation Research on Interturn Short Circuit of Transformer Winding Based on Finite Element Method

Interturn short circuit of power transformer winding will lead to the saturation of transformer excitation, the increase of magnetic leakage and overcurrent, and it will damage the internal structure of transformer, even causes burning accident. According to statistics, winding interturn short circuit accounts for about 50%~60% of all transformer winding faults. In order to map its interturn short circuit process, the existing models of transformer mostly utilize finite element method. According to this typical faults that cause singular points of physical quantities, the finite element model of transformer is established to simulate the transient characteristics and steady-state characteristics. The method of setting short-circuit faults in the finite element model of transformers is studied in this paper. The finite element coupling models of transformer is obtained, the interaction effect and coupling mechanism of physical fields under interturn short circuit fault conditions in which are in-line with already existing results. The distribution law of physical quantities and the constraint relation of fault parameters are revealed.