Fluctuation Mechanism of D. C. Partial Discharge in Polyethylene and Impulse Noise in Submarine Cable

It has been made clear theoretically and experimentally that the d.c. partial discharge in polyethylene occurs in accordance with the Poisson process. This phenomenon is explained by assuming that the fluctuation of the d.c. partial discharge is due to the fluctuation of the current density, that is, the fluctuation of the carrier concentration in polyethylene. The repetition rate of the d.c. partial discharge is closely related to the current density, and is expressed as f=f0Vnexp (-W/kT) (n=4, W=1.0 eV). It is then possible to estimate the number of impulse noises as a result of the d.c. partial discharge occurring in a cable, and to clarify the effect of the d.c. partial discharge on data transmission.