Modeling of transformer characteristics using fractional order transfer functions

In the advanced maintenance techniques of the transformer, Sweep Frequency Response Analysis(SFRA) method is one of the established technique that includes the modelling of the transformer frequency response. This includes identifying the transfer function and realising into circuit parameters so that the incipient fault detection is correlated with the changes in the circuit parameters. A fractional order transfer function has been observed to be most appropriate mathematical model for almost all the real time processes, the frequency response of the transformer being one of them is modelled in this paper. For the purpose of modelling of the frequency response into the fractional order transfer function, methods like Levy´s, Vinagre´s and Sanathanan´s and Koerner´s method were studied.