Application of pulsed x-ray induced partial discharge measurements

The use of short x-ray pulses (duration 50 ns) has shown to eliminate the statistical time lag by providing start electrons for the partial discharge (PD) development in a void, making it possible to detect very small voids at low electric field levels. A single x-ray pulse of a given dose produces a certain number of electron-ion pairs in a given gas volume, depending on the gas parameters. A minimum x-ray dose is thus needed to provide at least one start electron in the void for successful pulsed x-ray induced partial discharge (PXIPD) inception. In the application of x-rays to a conventional PD measurement, it is necessary to consider that photons emitted by the x-ray source are attenuated by every barrier material which is located between the source and the void of the insulator. This paper presents guidelines on how to design a successful PXIPD measurement with any given pulsed x-ray source. To do so, the theoretical background of PDs and the attenuation phenomena of x-ray are shown. The minimum x-ray dose for PD inception in artificially produced spherical voids is determined experimentally and evaluated theoretically.

[1]  L. Niemeyer,et al.  Measurement and simulation of PD in epoxy voids , 1995 .

[2]  G. Mole.  Location of discharging cavity in 33 kV metalclad busbar by the use of X rays , 1967 .

[3]  G. Mazzanti,et al.  First electron availability and partial discharge generation in insulation cavities: effect of light irradiation , 2005, IEEE Transactions on Dielectrics and Electrical Insulation.

[4]  L. Niemeyer.  A generalized approach to partial discharge modeling , 1995 .

[5]  Pulsed x-ray induced partial discharge: Phase and time-resolved measurements , 2011, 2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena.

[6]  L. Niemeyer,et al.  The importance of statistical characteristics of partial discharge data , 1992 .

[8]  N. Fujimoto,et al.  Partial discharge. XV. Improved PD testing of solid dielectrics using X-ray induced discharge initiation , 1992, IEEE Electrical Insulation Magazine.

[9]  Steven A. Boggs,et al.  Partial Discharge - Part 111: Cavitv-Induced PD in Solid Dielectrics , 1990 .

[10]  S. Adili.  Pulsed X-ray induced partial discharge measurements , 2013 .

[11]  S. Boggs.  Partial discharge. III. Cavity-induced PD in solid dielectrics , 1990, IEEE Electrical Insulation Magazine.

[12]  A general stochastic approach to partial discharge processes , 1998, ICSD'98. Proceedings of the 1998 IEEE 6th International Conference on Conduction and Breakdown in Solid Dielectrics (Cat. No.98CH36132).

[13]  I. Gallimberti.  Impulse corona simulation for flue gas treatment , 1988 .

[14]  M. G. Danikas,et al.  Partial Discharges in Ellipsoidal and Spheroidal Voids , 1991 .