Wideband equivalent circuit modelling and parameter estimation methodology for two-winding transformers

A wideband, lumped-parameter equivalent circuit model topology for two-winding power transformers is proposed. This model topology is designed to reflect the internal electromagnetic behaviour of such transformers. A parameter estimation methodology is presented for determining the parameters of the proposed model structure from measured frequency responses of the open- and short-circuit input impedances and the voltage transformation ratios. Measured and simulated frequency- and time-domain results are presented for a 16 kVA, 22kV/240V distribution transformer. These results show that the proposed model accurately predicts the transformer terminal responses in the frequency range between 10Hz and 100kHz.