摘要
[目的]单相接地故障占配电线路总故障次数的80%以上,且绝大多数相间故障均由单相接地故障发展而来。在地铁配电系统中,若0.4 kV开关柜无法及时切除单相接地故障,可能导致人员触电风险增加,同时接地点产生的电弧和电火花可能进一步引发火灾和爆炸等严重危险。因此,有必要对0.4 kV开关柜的单相接地故障保护进行深入分析,并合理设置保护措施。[方法]结合地铁特点和相关规范手册要求,提出0.4 kV主母排和0.4 kV配电线路的单相接地故障保护配置、整定原则、灵敏系数校核和时序配合要求。明确0.4 kV进线柜接地故障保护设置方案;明确典型0.4 kV馈线的短延时整定电流值;对于过流保护兼作0.4 kV馈线接地故障保护的最大电缆长度进行简化计算;对典型接地故障保护原理和整定原则进行分析。[结果及结论]针对地铁系统的特点,提出了以下保护方案:利用35 kV高压侧的过流保护兼作0.4 kV主母排的单相接地故障保护;对于0.4 kV进线单相接地故障保护,建议动作于报警模式;在0.4 kV馈线回路中,优先采用过流保护作做单相接地故障保护,当不满足兼作要求时,推荐设置零序过流型接地故障保护。
[Objective]Single-phase grounding faults account for over 80%of the total distribution line faults,with most inter-phase faults originating from single-phase grounding faults.In metro power distribution systems,failure to promptly isolate single-phase grounding faults in 0.4 kV switchgear may increase the risk of electric shock to personnel and lead to arcs and sparks at the fault site,potentially causing fires and explosions.Therefore,it is essential to thoroughly analyze single-phase grounding fault protection for 0.4 kV switchgear and establish appropriate protective measures.[Method]Based on the characteristics of metro systems and relevant regulatory guidelines,requirements of single-phase grounding fault protection configurations,principle setting,sensitivity coefficient check,and time sequence coordination for 0.4 kV main busbar and 0.4 kV distribution lines are proposed.The protection scheme for grounding faults in 0.4 kV incoming panels is clarified.The typical short-time delay settings for 0.4 kV feeder circuits are clarified.Simplified calculations are performed to determine the maximum cable length for using overcurrent protection as dual-purpose grounding fault protection for 0.4 kV feeders.Principles for grounding fault protection principles and setting criteria are analyzed.[Result&Conclusion]Based on the characteristics of metro systems,the following protection schemes are proposed:using overcurrent protection on the 35 kV high-voltage side to serve as single-phase grounding fault protection for the 0.4 kV main busbar;for single-phase grounding fault protection in 0.4 kV incoming circuits,it is recommended to operate in alarm mode;in the 0.4 kV feeder circuits,prioritize using overcurrent protection as dual-purpose grounding fault protection,and if dual-purpose requirements are not met,zero-sequence overcurrent grounding fault protection is recommended.
作者
周文卫
ZHOU Wenwei(China Railway Siyuan Survey and Design Group Co.,Ltd.,430063,Wuhan,China)
出处
《城市轨道交通研究》
北大核心
2025年第3期128-133,共6页
Urban Mass Transit
作者简介
通信作者:周文卫,高级工程师,308562526@qq.com。
