Modeling and numerical analysis of corona-induced vibration on high-voltage transmission line with raindrops

Abstract

In rainy days, rainfall hitting high-voltage transmission lines forms raindrops that suspended to lower surface of the conductors. The suspended raindrops subjected to electric field take a cone shape, which leads to a drastic increase in local electric field and amplifies the corona discharge. Electrostatic attractive force between the conductor and the ground is partially shielded by space charge during the corona discharge. Intermittent shielding and the time lags may be the main causes of this phenomenon namely corona-induced vibration. Like any other mechanical oscillations, this kind of vibration may result in fatigue damages of conductors, failures of insulator strings and spacers. This paper is to validate a numerical model based on the finite element method and Newmark algorithm to reveal the formation mechanism of the corona-induced vibrations. According to the numerical model, the effect of rain intensity, electric field and applied voltage on vibration amplitudes and natural frequency are systematically investigated. The results agree well with experimental data available in the literature. The model and numerical analysis method enable a better comprehension of the formation mechanism of the corona-induced vibrations.