NONLINEAR TRANSFORMER WINDING OSCILLATIONS

In this paper the transformer winding has been seperated into several parts where each part includes a self-inductance, and mutual - inductance (with other parts). Meanwhile each part of the winding has a capacitance with the other parts and transformer thank. A simple method for representation of nonlinear behaviour of the core is to modify Lij in the inductance matrix, at the end of each step considering the flux of each part of the winding. As a result, the volume of computation will be very large even a piecewise linear model is used. However, this paper gives a new method to overcome this problem. In this method without loss of precision, the switched inductance concept and the effect of the saturation on matrix M, have been used to model the saturation. According to the model,a package has been written to study transient behaviour of the winding due to its excitation by switching surge. The simulation results, clearly show unexpected resonances due to the high residual flux and saturation. The results also reveal that, the nonlinear inductance may cause a chaotic behaviour in the system.