Operational analysis of DC protection system in Guangzhou converter station

DC protection system is one of the most important equipments in HVDC transmission system. In this paper,the operational experience of DC protection system in Guangzhou converter station is concluded,the primary abnormity and the reconstruction in operation are analyzed,then,some questions of design and manufacture which exposed in operation are discussed. All above are not only valuable to improve the ability of operation and maintenance to insure the safety and the reliability of HVDC system,but also benefit to improve the design,commissioning and operation level of HVDC power transmission projects in China in the future.