Dynamic Rating of 110 kV Overhead Lines

Abstract

The paper justifies the need of using, within the 110 kV networks, a dynamic line rating model along the power lines. The work describes in detail the way in which the dynamic line rating is determined, basing the process solely on measurement of the weather conditions. Some aspects related to selection of the numerical values of the coefficients present in the heat model of the power-lines, which is being used to determine the dynamic line rating and the distance between the ground and the conductor, have been described. Subsequent stages of implementation of the system used to determine the dynamic line rating of the power lines have also been described. These include selection of the critical spans of the overhead lines, in case of which risk of exceeding the distance to the crossed-over objects is higher than in case the of the other spans of the very same power line. Additionally, optimal displacement of the weather-reporting stations, that are the source of the data used to determine the dynamic line rating of the lines, has been described. The work also deals with applications of the dynamic line rating for the power line related to the dangerous situation in case of which rime (ice) would be accumulated on the conductors. The forecasting procedures, regarding the load imposed on the power-lines, within a defined time period are also considered by the present paper. Forecasting the permissible load for the power lines is one of the main elements of planning an energy transmission system. Conclusions have been drawn regarding selection of the methodology which is to be used to determine the dynamic line rating, and the way of implementing and using these conclusions within the scope of maintaining the electric energy network.

Keywords

• dynamic line rating
• thermal line model
• load forecasting