Modeling transformer internal faults using MATLAB

This paper describes a technique for modeling transformer internal faults using MATLAB. In this technique a model for simulating a two-winding-single-phase transformer is modified to be suitable for simulating an internal fault in one of the windings. The transformer is represented by three windings in this case; one winding is the healthy winding, while the other two represent the faulty windings. Three differential equations representing these windings are simulated and solved using MATLAB/SIMULINK. Simulation results include inrush magnetizing current and internal fault current. Fast Fourier transform (FFT) is used to analyze the simulated currents, and it shows that the second harmonic component of the internal fault current is not predominant which agrees with transformer theories.