Analysis of Vibrations of Overhead Power Lines During Ice Melting with Direct Current

The article analyzes the relationship between the ice melting current, temperature distribution and vibration of overhead power line wires, which is based on the use of the series connection method to obtain the connection equation between the electrical and thermal energy released during the process of melting ice on wires with a direct current. Usually, in the case of calculating ice melting modes, the problem of choosing such a melting current value is solved, at which, under given meteorological conditions, ice will be removed in a given time. For a specific ice melting scheme, such a current remains practically unchanged for all weather conditions, therefore, there is always a fear that the current value in this scheme may be insufficient for successful ice melting under certain unfavorable, but possible ice wall thickness, wind speed and ambient temperature. The article, based on the refined model of ice melting, considers the method of determining the actual range of meteorological conditions under which, for a given current value, successful ice melting is ensured. Usually, in the case of calculating ice melting modes, the problem of choosing such a melting current value is solved, at which, under given meteorological conditions, the ice will melt in a given time. Such a formulation of the problem is suitable for overhead lines equipped with special ice melting installations with an adjustable current value. provided that the ice melting current in all weather conditions does not exceed the permissible value. For overhead lines that do not have such installations, the ice melting current is not regulated, its value must be chosen taking into account a number of restrictions (mechanical strength of wires, power supply capacity, ice melting power scheme, length of the ice melting zone, etc.). Experience in operating electric networks shows that ice-wind accidents on overhead lines are among the most severe, and can disrupt the power supply of large economic areas of the regions of Ukraine. The issue of preventing ice-wind accidents on overhead lines is also relevant for main electric networks. It should be noted the significant economic damage from ice-wind accidents on the Western electric power system in the autumn-winter periods: 2004—2005, 2010—2011 and 2012—2013.