On the role of the space charge produced by hanging water drops in the mechanism of the corona-induced vibration of high-voltage conductors

Abstract

Although the corona-induced vibration of overhead transmission lines, i.e. the vibration excited by the water drops hanging from the conductors, has been reported by the utilities since 1932, the mechanism responsible for the vibration is not fully understood. The present paper shows that a high-voltage conductor vibrates even when the hanging water drops are replaced by conical metal points, and an impulse voltage, its frequency being equal to the natural frequency of the system, is applied to the conductor. In addition, it was observed that even in the absenced of ionic wind, a H.V. sphere electrode suspended above a plane electrode vibrates when an intermittent space charge is injected in the space between the sphere and the grounded plane. Thus, the intermittent shielding effect of the corona space charge, produced by the water drops hanging from the conductor, would appear to be the cause of the vibration.