Analysis of phase-resolved partial discharge patterns of voids based on a stochastic process approach

Abstract

A method is presented for the determination of physical discharge parameters for partial discharges (PDs) of voids in solid insulation. Based on a recently developed stochastic theory of PD processes, a statistical analysis of a measured phase-resolved partial discharge (PRPD) pattern allows the determination of the relevant physical parameters like first electron availability or decay time constants for deployed charge carriers. These parameters can be estimated directly from the measured patterns without the need of performing simulations. Furthermore, error bounds for the parameter values can be given.The parameter estimation algorithm is based on the analysis of a contiguous region of the PRPD pattern where this region can be chosen nearly arbitrarily. Thus, even patterns with several active PD defects or patterns which are corrupted by noise can be analysed.The method is applied to a sequence of patterns of a void in epoxy resin. The change in first electron availability in the course of a day can be determined quantitatively from the data while the other physical parameters remain constant.

Mathematical Aspects of Krätzel Integral and Krätzel Transform

“…For an application of this type of unconditional density for k = 3, see [9]. When all the densities involved in Equations (21) and (22) are continuous, we also call Equations (21) and (22) as continuous mixtures.…”

Numerical modeling of partial discharges in a solid dielectric-bounded cavity: A review

“…Several factors may be attributed to cause the stochastic behaviors, such as the probabilistic nature of the processes that lead to discharge initiation, growth and surface charging dynamics [107]. Except few models based on stochastic process [108,109], the discharge growth is usually considered to be deterministic in simulations, and the stochastic characteristics are controlled by the two other factors.…”

Frequency-time diagram of partial discharge pulses recorded on large generators

“…Треба напоменути да се могу појавити слични облици поља (кластера) за различита пражњења или потпуно различити облици поља за иста пражњења. Поред тога, појављују се разни додатни ефекти као што су интерференције, суперпозиције, преслушавања итд [3,4].…”