Study on stability of ±800kV UHVDC transmission project

A number of Ultra High Voltage Direct Current (UHVDC) projects are planned currently in world wide, particularly for large hydropower projects in China. The stability of ±800kV UHVDC transmission system and its receiving system is analyzed in this paper, based on the UHVDC transmission project from Xiluodu Left Bank to Zhuzhou in the first period of Jinsha River DC project. According to the system model, basic conditions and demands of UHVDC transmission project are presented. Considering the practical situation and grid planning of receiving system in this project, an initial analysis for receiving end applicability is made by calculating power flow under the conditions of both normal and N-1 lines operation. Detailed discussion on the impact of both monopolar and bipolar block on DC lines are given, and short circuit current and three phases fault near inverter station are also studied. The results can contribute greatly to UHVDC project.