柔性直流换流站直流接地点选择探讨

Discussion on Selection of DC Grounding Point for Flexible DC Converter Station

为了保障人的安全和设备绝缘免于被破坏,文中通过对一种真双极柔性直流输电工程主接线存在的可能运行方式进行分析,提出了系统安全运行的接地方式,并比较了在单端接地运行方式下,设立独立的直流工作接地极和与换流站共用接地极的优缺点。最后通过计算分析得出采用共用接地极,在发生单相接地故障时,地网电位的升高对设备和人身安全的影响,提出了可靠的运行方式和接地方案。

In order to protect people’s safety and protect the equipment from being destroyed,the possible operation way of a true bipolar flexible DC transmission project is analyzed in this paper.The grounding of system security operation is proposed based on the analysis.In a single-grounded mode of operation,the advantages and disadvantages,separate DC grounding electrode and common grounding with the converter station pole,is compared.Finally,in the event of single-phase ground fault occurs,the impact of equipment and personal safety is analyzed after increased ground potential,based on the calculation and analysis of sharing earth electrode,a reliable operation mode and grounding scheme is put forward.