一起换流站内接地网过流保护动作故障分析

Analysis of an Overcurrent Protection Action Fault at HVDC Converter Station

分析了贵广Ⅱ回直流在单极金属回线模式运行时发生的一起换流站内接地网过流保护动作故障,指出故障的诱因是直流线路高阻接地,而深层的原因则在于部分直流保护设计不完善,并给出了相应的直流保护优化整改措施。实践证明,这些措施有效地提高了直流输电系统运行的可靠性。

An overcurrent protection action fault at the converter station of Guizhou-Guangdong Ⅱ HVDC transmission line in its uni- polar metallic return mode has happened. This paper analyzes the fault in detail, pointing out that a high-impedance grounding fault of the line leads to the fault, but the underlying reason of the fault is the improper design of the protection, and giving forward corre-sponding optimal measures. The practice shows that the proposed measures are effective to inprove the operation reliability of the HVDC line.