云广与贵广Ⅱ回直流工程共用接地极的过流风险分析与控制

Analysis and Control of the Over-current Risk in the Common Grounding Electrode of Yunnan-Guangdong and Guizhou-Guangdong Ⅱ DC Projects

为了节省用地和降低工程造价，云广直流工程与贵广Ⅱ回直流工程在广东省内共用一个接地极。基于直流过负荷逻辑和接地板过流保护分析了共用接地极的过流风险，指出在两回直流同名极同时跳闸且运行极均短时过负荷运行时，将会出现共用接地板电流超过最大耐流值的情况。针对这种过流风险，从调度运行层面上提出调控措施及彻底解决问题的建议。

For terra saving and cost reducing, Yunnan-Guangdong DC project uses a common grounding electrode with Guizhou-Guangdong II DC project in Guangdong province. Based on DC overload logic and grounding electrode overcurrent protection, this paper analyzes the overcurrent risk in the common grounding electrode, pointing out that the current of common grounding electrode will exceed the maximum resistance value in the case where the same-name poles of the two DCs trip at the same time while the remaining running-poles are in overload operation in a very short time. Against the risk, the control measures are proposed from the view of dispatching operation, and correlative recommendations are made to solve completely the problem.