In this paper,an incident of differential protection action of pole 1 caused by lightning strike during the normal operation of three-terminal bipolar four-valve group at Liuzhou converter station is taken as the research object.It is pointed out that the fault is divided into two stages.The first stage of the Kunliu section of the line was struck by lightning,but the line protection did not work;The second stage is that the overvoltage of Liuzhou station causes the action of the arrester of the low-end converter of pole 1 during the recovery process of lightning strike,and the current into the ground is generated after the arrester action,which causes the differential current of the low-end converter of pole 1 to produce differential current,which leads to the HVDC differential protection action of pole 1,and at the same time causes the protection action of the arrester overvoltage discharge.The optimization measures of HVDC differential protection operation logic are proposed.
关键词
线路保护/直流差动保护/雷击/过电压/避雷器
Key words
line protection/DC differential protection/lightning strike/over voltage/lightning arrester
维普
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