Research on Comprehensive Optimization of Power Intensive UHV/EHV Sending Power Grid

They were studied mainly that improving the power exporting capability of large-scale power grid with intensive electricity and the quality of power grid planning, on the premise of ensuring the security of power system. In view of the problems faced in planning and operation periods of such power grid, 3 kinds of sending power grid structure schemes were proposed, including single point AC interconnection, multipoint AC interconnection and single point AC with the addition of DC back-to-back interconnection between the newly-built higher voltage power grid and the existing power grid. The differences of the proposed structures were discussed including technical characteristics, power delivery capability, economy and so on. Then, it was clarified that the influence on improving the power transmission capacity of power grid of the connecting mode. It was shown that the number of connection points should be considered based on the demand and constraints of power transmission in different developing stages. Finally, the case study was carried out on some ultra-high voltage power grid planning.