Research of the control strategies for the ±500kV Xiluodu-Guangdong double-circuit HVDC project

The ±500 kV Xiluodu-Guangdong HVDC transmission project is the first double-circuit project putting into operation in China and its rated DC power is 6400 MW. This project is designed in a scheme that two DC circuits use common earth electrode, share primary equipments in AC yard and four DC transmission lines are erected on the same tower. In contrast to traditional bipole HVDC project, the double-circuit project need more complicated DC control system and control strategies. This paper focuses on the research of the control strategies for this project.