Study On The Ultra High Voltage Direct Current Transmission Technology And Its Application

The use of Ultra High Voltage Direct Current (UHVDC) at ±800 kV has been found economicallyattractive for power transmission up to 6400MW for distance above 1200km. The development of thehydro rich regions in Southwest China about 2000 km away from the load centers in East and SouthChina makes it necessary to develop transmission systems for UHVDC ±800 kV, in order to reduceinvestment, save land and reduce losses. ±800kV UHVDC is suitable for Xiluodu and Xiangjiaba HPPtransmission project. The use of 800kV UHVDC technology will be achievable in the near future witha limited amount of development. Most of the DC equipment can be easily modified for 800kV, suchas thyristor valve and DC filter capacitors, only the converter transformer and wall bushing need to bedeveloped. The famous international companies have recently launched a comprehensive R&Dprogram to meet these challenges with the goal to meet the first UHVDC project delivery scheduleplanned by China power utilities.