Talking about the requirements of wire selection for UHV overhead transmission lines

The choice of wire is an important subject of UHV transmission technology. It not only needs to meet the requirements of electric power transmission, but also ensures that the line can operate safely and reliably and meet the requirements of environmental protection, and it is also economically suitable. Therefore, the wire selection needs to consider various factors such as the transmission capacity, transmission performance, environmental impact (corona, radio interference, noise, etc.) of the line, and analyzes the three aspects of the electrical characteristics, mechanical characteristics and investment of the wire. Detailed technical and economic comparisons have been made with the split pattern, recommending technically and economically optimal wire cross sections and split patterns. In principle, the following factors should be considered in the selection of conductors:

(1) Allowable temperature rise of the wire;

(2) Environmental impacts, including radio interference, corona noise, etc.;

(3) conveying capacity and economic current density;

(4) Corona threshold voltage;

(5) Mechanical strength. According to the research, the Jindongdong-Nanyang-Jingmen test demonstration project selects eight splits per phase and is arranged in a regular octagonal shape with a single conductor section of 500 square millimeters. For local areas where the installation requirements of the conductor environment are particularly strict, the use of expanded diameter conductors, the addition of virtual self-conductors, and the use of low-noise conductors in the middle or three phases will be carried out through research.