Variations in the stochastic behavior of partial-discharge pulses with point-to-dielectric gap spacing

The stochastic behavior of AC-generated partial-discharge (PD) pulses in a point-to-dielectric air gap has been thoroughly characterized from direct measurements of various conditional and unconditional phase-restricted pulse-height and phase-of-occurrence distributions. A stochastic analyzer was used to examine changes in the stochastic behavior of PD pulses that occur when the gap distance between a point electrode and a solid planar dielectric surface is varied. The results reveal significant pulse-to-pulse and phase-to-phase memory propagation at all gap spacings. The observed memory effects are seen to be important in controlling the initiation and growth probabilities of partial-discharge pulses at any given phase of the applied voltage