金属回线纵差保护在普侨特高压直流输电工程中的应用

针对单极金属回线运行时的金属回线故障,在研究南网天广、高肇、兴安、云广I等工程的直流保护系统的基础上,普侨特高压直流输电工程的直流保护系统首次设置了金属回线纵差保护。首先详细阐述了金属回线纵差保护的原理,并介绍了与其他线路故障后备保护的配合;接着借助RTDS实时仿真系统和普侨直流实际的控制保护装置组成的闭环系统进行了实验验证。从实验结果可看出新增保护的有效性和与其他保护配合的合理性,能有效减少由于金属回线的瞬时故障造成的系统停运,提高了系统运行的可靠性。目前,金属回线纵差保护已经在普侨工程的直流保护系统中实施,运行良好。

Application of Metallic return Longitudinal Differential Protection on Pu-Qiao UHVDC Transmission

Based on the research on Tian-Guang, Gao-Zhao, Xing-An and Yun-Guang I HVDC transmission projects, metallic return longitudinal differential protection is first used on Pu-Qiao UHVDC Transmission for the metallic line fault in metallic return operation. In this paper, the principle of metallic return longitudinal differential protection is described in detail and the cooperation of backup line fault protection is introduced first; then, the experiment is did on platform composed of RTDS and the control and protection system of Pu-Qiao UHVDC Transmission. The experiment results show that the new protection is effectual and legitimate cooperated with backup protection. So the used of the new protection can reduce the system stop by metallic line fault effective and improve the reliability of system running. Now, metallic return longitudinal differential protection is executed on Pu-Qiao UHVDC Transmission protecting system, the operation is normal.