A study on the propagation character of the local discharge under low air pressure

Recently with increasing air pollution, the pollution of insulators in high altitude areas has been paid more and more attention. From this, the propagation characteristics and propagation mechanism of the local discharge on the electrolytic surface, which simulates the surface of wet polluted insulators, set in low-pressure have been investigated. The tip of the local discharge, which propagates on the solution surface, emits a strong light. It bas been found that the propagation velocity of the local discharge depends on the intensity of the photoemission from the local discharge tip. In this paper, the relations between the propagation velocity and the intensity of a line spectrum of light from the local discharge tip are examined under the impulse voltages, when the peak value of the applied voltage, the applied voltage waveform, the air pressure and the resistivity of the solution are changed.