The Research Of Conductor Of Dalian 500kV Transmission Line

The electricity is the essential element for residents living and industrial development, and the electricity transmission is the foundation of power system. Comparing to the underground cables, the transmission line has the advantages of low construction cost, short construction period and convenient maintenance, therefore the transmission line is more commonly used. The reasonable selection the section and bundled configuration is directly related to the transmission line construction cost, technical characteristics and the operating cost. So the issue of conductor type selection of transmission lines is actually to meet the requirements of the technical characteristics firstly, and then to balance initial investment and operating cost. This research analyses the conductor type selection for Dalian 500kV transmission line.At first, nine kinds of conventional wire and an expanded diameter wire as alternative wire schemes are put forward. On the technical aspect, this research has carried on the calculation of the audible noise, radio interference, corona loss, resistance loss, heat check, minimum line height, natural power and mechanical characteristics to adapt the lines to weather conditions and terrain conditions. The alternative schemes are compared from a technical point of view, and whether these results are in accordance with the relevant provisions and the requirements of the national standard are determined. Based on the results, the six split wire schemes have a great advantage, which including 4xLGJ-400/35 and 4×LGJK-300/50 schemes.On the economic aspect, there is a need to balance the initial investment and the operating cost. In order to save initial investment, it requires wire section to be smaller. In order to reduce the energy loss, it requires larger conductor section. So it should be a comprehensive analysis. The analysis from two aspects of initial investment and operating cost of various wire schemes are done. From the aspect of initial investment, the 4×LGJ-400/35 scheme is at the second place. From the point of view of operating cost,4×LGJ-400/35 is one of the best.Finally by considering two aspects of technology and economy, it is determined that the wire type of 4×LGJ-400/35 scheme is the wire type of Dalian 500kV transmission line.