摘要
[目的]接地故障保护因校验计算复杂而长期被忽视,这导致了工程设计中的安全隐患。因此,有必要对地铁车站接地故障保护进行深入分析,从而保障工程的安全性。[方法]考虑外部误差的潜在影响,引入了接地故障电流倍数的概念,并将其与断路器脱扣器的整定范围进行对比,以便于高效地进行接地故障保护的灵敏度校验。通过对地铁车站实际数据的详尽计算分析,以及对结果的归纳和总结,明确了需进行接地故障保护灵敏度校验的回路范围,并确定了相应的接地故障保护配置策略。[结果及结论]变电所馈线断路器推荐使用电子脱扣器,通过合理设定短延时电流的整定值,通常可实现短延时保护与接地故障保护的双重功能。配电箱馈线回路则需根据具体情况进行接地故障保护的灵敏度校验,尽管进线电缆的影响相对较小,但仍需予以适当考虑。断路器的额定电流应依据实际需求选择,不宜过大,并需合理选择脱扣曲线以确保其性能。在采用具备接地故障保护功能的断路器时,应特别关注上下级保护之间的协调配合。此外,还提供了地铁配电系统中,当断路器用作接地故障保护时,铜芯电缆的最大允许长度,供相关设计人员参考。
[Objective]Grounding fault protection has long been neglected due to the complexity of verification and calculation,leading to safety hazards in engineering design.Therefore,it is necessary to conduct an in-depth analysis of grounding fault protection in metro stations to ensure engineering safety.[Method]Considering the potential impact of external errors,the concept of grounding fault current multiple is introduced and compared with the trip range of circuit breaker tripping devices,so as to facilitate efficient sensitivity verification for grounding fault protection.Detailed calculations and analysis of actual data from metro stations are conducted,and the results are summarized to define the circuit range requiring sensitivity verification and determine the corresponding grounding fault protection configuration strategy.[Result&Conclusion]It is recommended that electronic trip units be used for substation feeder circuit breakers.By appropriately setting the short-time delay current value,the dual functionality for short-time delay protection and grounding fault protection can typically be achieved.For distribution box feeder returning circuits,grounding fault protection sensitivity verification should be performed based on specific conditions.Although the impact of incoming cables is relatively small,it still needs to be appropriately considered.The rated current of circuit breakers should be selected according to actual needs and should not be excessively high.The tripping curve must be reasonably chosen to ensure the performance.When using circuit breakers with grounding fault protection functions,special attention must be given to the coordination between upstream and downstream protection devices.Additionally,when circuit breakers are used for grounding fault protection in metro distribution systems,the maximum allowable length of copper core cables is provided for reference to relevant designers.
作者
周龙
ZHOU Long(China Railway Siyuan Survey and Design Group Co.,Ltd.,430063,Wuhan,China;New-type Rail Transit Design and Research Institute of China Railway Siyuan Survey and Design Group Co.,Ltd.,215009,Suzhou,China)
出处
《城市轨道交通研究》
北大核心
2025年第3期148-153,共6页
Urban Mass Transit
关键词
地铁车站
低压配电
接地故障保护
灵敏度校验
保护允许线路长度
metro station
low-voltage distribution
grounding fault protection
sensitivity verification
allowable cable length under protection
