Research On The Characteristics Of UHV Six-phase Transmission Line

Because the origin of energy and the center of load in C hina distributed unevenly, so we need strong supports from UHV power grid for whether it is the transmission of a large capacity, long distance energy, or the allocation of resources optimization, as well as large scale access to new energy sources and haze governance. However, the UHV transmission lines need to line corridor wider, but also by the geographical conditions and environment protection limits. Compared with the traditional UHV double- circuit transmission system, UHV six phase transmission system has the advantage of high power transmission density, narrow line corridor occupancy and low general construction costs,so the application of the six-phase transmission technology to UHV transmission will be a good choice. In this paper, the main technical features and charac teristics are analyzed and discussed in detail, providing a theoretical basis for the economy, feasibilit y and further study of UHV six-phase transmission system.This paper take the Huainan-Shangha i double- circuit transmiss ion line as a reference. Then the typical size of tower is designed and the bundle conductor type as well as insulator lengt h is selected for the six-phase transmiss ion system. Based on this, the electrical parameters of UHV six phase transmiss ion lines were calculated, and the distributed parameter equivalent circuit model are established. Then, the power transmission characteristics, unbalance degree, the maximum conductor surface electric field intens ity and the space electric field distribution above the ground are calculated. C omparison and analys is on the calculation results for six-phase transmission line and those for double-circuit transmission line with corresponding voltage levels are performed. Analys is results show that UHV six-phase transmission lines have higher power transm ission density, also the unbalance degree, the conductor surface electric fie ld and the space electric fie ld of six-phase transmission line are better than those of double- circuit transmission line. And, both the economic performance and the environmenta l performance of six-phase transmission line are better.