A survey of methods for improving the UHV power system transfer capacity

With the rapid growth of power load and the integration of large-scale renewable energies, long distance and large capacity Ultra High Voltage (UHV) transmission will be the trend of future power grid in China. Based on the background of UHV grid, and combined with advanced experiences of improving transfer capacity of power grids all over the world, especially the application of advanced techniques, new materials and advanced methods, this paper analyses main factors and limited reasons which affect the transmission capacity of UHV grid. Then it presents existing methods and characteristics of improving grid transfer capacity, which can be divided into three categories, including changing the power grid structure, changing the grid electrical characteristics, installing the security and stability control equipments.