A study of the short-circuit impedance of transformer windings based on COMSOL Multiphysics simulations

Abstract

In this thesis, a three-dimensional field-circuit coupled model of a single-phase transformer with a crossover winding structure is developed in COMSOL Multiphysics to explore the effects of different winding arrangements on short-circuit impedance. Four typical arrangements are simulated under steady-state and transient short-circuit conditions. The results reveal that the PSSPPS arrangement produces the highest short-circuit impedance and has stronger short-circuit current suppression capabilities, making it a recommendation in this study. In contrast, the PSPSPS arrangement results in the lowest impedance, and the other two types show moderate impedance. The distribution of magnetic flux density, magnetic field strength, and relative permeability further confirms the theoretical relationship between magnetic paths, reluctance, leakage reactance, and short-circuit impedance.

Based on these findings, an optimization method is proposed to centrally distribute the high-voltage windings within the core. Consequently, this thesis not only reveals the essential influence of winding arrangement on short-circuit impedance but also provides design ideas for the arrangement of high and low voltage windings of transformers. It strongly contributes to improving the operating stability of the power system and the fault resistance of transformers.