Dielectric response measurement of power transformer bushing by utilizing high voltage transients

Insulation has a significant role in most of power components failures. Therefore, proper diagnostics of insulation condition which can be done non-destructively and online in the field is of interest. In this paper, a new insulation diagnostic technique is proposed which utilizes natural transients in power system for online dielectric response measurement. In the proposed technique, lightning and switching impulses with wide range of frequency are used as stimuli for dielectric spectroscopy. Oil impregnated papers and condenser bushing are the objects under investigation and dielectric response of them is derived at those transients. Dielectric responses obtained by this method are verified by the responses measured by insulation diagnostic systems IDAX and LCR meter.