Modeling of Partial Discharge in Transformer Winding by Multi-Conductor Transmission Line Model

摘要

To locate accurately the occurrence of a partial discharge in a power transformer winding, a wide frequency band model of the winding is required. In this paper a wide frequency bandMulti Conductor Transmission Line model (MTL) is employed to simulate the propagation of PD signal in transformer windings. The MTL model is briefly reviewed and the related equations of the model are reformulated to easily simulate occurrence of a PD signal along the winding. Software is developed in Matlab to calculate the windings resonance frequencies and the magnitudes of over-voltages occurring between different disks along the winding. Then propagation ofPD signal in a power transformer (900MVA, 525kV), is simulated using the (MTL) model with frequency dependent parameters. Also this method is employed to model the laboratory transformer winding.