Modelling and characterisation of hysteresis phenomena in three phase power systems for diagnostic purposes

This paper focuses on finding possible means of identifying winding defects by looking for special features in the Fourier transform of hysteresis signature of the earth current. The effect of the magnetic characteristics of the iron material on the dynamic behaviour of the system will be taken into account. The method is based on simulations of the dynamic magnetic behaviour of the magnetic material. For this purpose, a model of the three phase transformer will be used as an example. Experimental study of the magnetic material will be performed to characterise its dynamic behaviour. The results from the experiments are used in the simulation of the hysteresis phenomena. Using these data, harmonics due to saturation and hysteresis could be quantified and their sensitivities to defects could be analysed, thus paving the way to a soft sensor approach in identifying methods and routines for detecting winding defects.