FE-Based Modeling of Single-Phase Distribution Transformers With Winding Short Circuit Faults

This paper presents a fast and accurate phase variable model of single-phase distribution transformers with internal winding short circuit faults. The flux linkages of windings (including the winding formed with the shorted winding turns) are used as the phase variables. Their variation with the winding currents is used to represent the nonlinear magnetization of the iron core. The flux linkage variation is obtained from the solutions of a series of FE computation, covering the full operation range of the transformer with short circuit faults. It is described using tables and utilized by table look up in the developed model. An equivalent magnetizing current is defined to reduce the number of the FE computations for building the flux linkage tables. The implementation of the proposed FE-based model is studied and the verification is performed. Also, the application examples are presented