Analysis of Influence Factors on the Transmission Capability of the Yu-e Back-to-back VSC-HVDC South Channel

Yu-e back-to-back VSC-HVDC networking project is the first VSC-HVDC networking project whose voltage and capacity is up to±420kV and 5000MW. Currently, it is the VSC-HVDC project of highest voltage and largest capacity in the world which realizes the asynchronous networking between Southwest and Central China power grid and guarantees the safety of hydropower delivery between these two power grids. However, it may cause the units of Enshi and Three Georges power plant unstable when power is transmitted from Southwest power grid to Central China power grid through Yu-E back to back VSC-HVDC project. In view of the problems above, this paper studies the influence of the nearby Yihua HVDC transmission power, the up-delivery power of 500kV Enshi main transformer and output of the adjacent hydropower plant on transmission capability of Yu-E back-to-back VSC-HVDC system.