Influence of the Parameters of Disk Winding on the Impulse Voltage Distribution in Power Transformers

Overvoltage distribution along the transformer winding must be uniform to certify the safety of the operation of the power transformer. Influence of the parameters variation on the impulse voltage distribution (IVD) in disk winding transformer is going to be analyzed which hasn’t been analyzed on this type of winding in the previous papers. In this research, a transformer with disk winding and rectangular cross-section is analyzed. Equations for capacitances between winding turns and also equations for capacitances between turns and core are deduced. Noting that the relationships presented are dependent on the parameters of the transformer winding, so with changing these parameters, the capacitances of turn –turn and turn – core and finally the capacitances of total series and parallel of the winding will be changed. The purpose of this paper is to show the effect of the variations of these parameters on the IVD in disk winding of transformer. This paper, will assess how to change the parameters of disk winding in order to achieve a uniform initial IVD along the winding and to reduce the amplitude of impulse voltage fluctuations (AIVF) in winding and which parameters have more effect in making uniform the IVD on the disk winding.