degradation of oil impregnated paper insulation under influence of repetitive fast high voltage impulses

Partial Discharge Signatures of Defects in Insulation Systems Consisting of Oil and Oil-impregnated Paper

Determination of moisture diffusion coefficient for oil-impregnated Kraft-paper insulation

Article history: Received 4 September 2012 Received in revised form 25 April 2013 Accepted 2 May 2013

Breakdown Voltage and Its Influencing Factors of Thermally Aged Oil-Impregnated Paper at Pulsating DC Voltage

Breakdown strength is an important electrical property of insulating paper. Oil-impregnated paper of various aging states was prepared. Its breakdown voltage was then measured at pulsating direct current (DC) voltage with various ripple factors, and alternating current (AC) and DC voltage for comparison, respectively. The AC breakdown voltage is the smallest, and pulsating DC (r = 1/5) breakdow...

Diagnostics of Oil-Impregnated Paper Insulation Systems by Utilizing Lightning and Switching Transients

Development of the power grid towards a more reliable and smarter system requires frequent on-line monitoring of the power components. Power transformers and their bushings are particularly important components in a power transmission system and their insulation degradation may lead to catastrophic failures. Time consuming and costly replacement of these components raise the importance of their...

Dielectric Response and Partial Discharge Diagnostics of Insulation Systems by Utilizing High Voltage Impulses

In this thesis, power system transients are considered as an opportunity for development of online diagnostics of power components and specifically the insulation systems of power transformers and bushings. Failures of power components and outages can lead to a huge economical loss in the electric power grid. Therefore reliable operation of power grid requires on-line monitoring and diagnostics...

Active high voltage insulation

This paper presents a new concept for an active high voltage insulation system with dynamic and adaptive features. The governing principle is based on surface charge accumulation on dielectrically covered electrodes in air under atmospheric pressure. This accumulation results in a charge-induced electric field component which steers the field distribution within the system advantageously. At eq...