Impulse voltage distribution in intershield disk winding VS interleaved and continuous disk winding in power transformer

Strike of a lightning stroke to the high voltage terminal of a power transformer results in an impulse stress on its windings. The magnitude of the series capacitance of the windings has an important effect on the impulse voltage distribution and the stresses along the windings. Increasing the series capacitances of the windings, the impulse voltage distribution becomes more linear and the stress on the winding is reduced. So interleaved windings rather than disk windings are used in power transformer windings to increase the series capacitances. In this paper, the electrostatic shielding, used in disk windings to increase the windings series capacitance, and for linearization of its impulse voltage distribution is introduced and its impact on the modification of impulse voltage distribution is compared with the disk winding without shielding.