韶关—广州段电气化牵引变电所越级跳闸的原因与处理对策

Causes and Solutions of Override Tripping in Traction Substations Between Shaoguan and Guangzhou

通过对韶关—广州段牵引变电所越级跳闸故障的分析检测,指出继电保护装置动作时限设置不合理是导致故障的原因,提出将馈线保护装置的阻抗Ⅱ段保护与过电流保护的动作时限由原设计的0.5s调整为0.4s,使主变27.5kV单相低压过电流保护与该保护的动作时限级差Δt由0.2s提高到0.3s。经此调整后满足了继电保护装置的选择性要求,保证了牵引供电系统的安全可靠运行。

By analyzing and testing override tripping faults in traction substations between Shaoguan-Guangzhou, this paper points out that unreasonable setting of time lag of action of protective relaying equipment is the cause of faults. And also it shows that adjusting time lag of action of impedance protection Ⅱ and over-current protection of the feeder from the designed 0. 5s to 0.4s may up grade difference At of time lag of action between 27.5 kV single phase low voltage over-current protection of the main transformer and that of the feeder from 0.25s to 0.3s. By this operation, not only selectivity of protective relaying equipment, but safety and reliability of traction power supply system can be guaranteed.