核电厂低压配电系统接地故障保护的设计与研究

Design and research of earth fault protection in low voltage distribution system of nuclear power plant

结合标准规范,给出了低压配电系统接地故障保护的设计原则及其与上下级保护配合的整定要求,设计了核电厂低压配电系统接地故障保护的典型配置方案。梳理了国内外核电厂低压配电系统发生接地故障造成变压器零序保护越级动作的案例,并进行原因分析。在典型配置方案的基础上,对核电厂低压厂用电系统接地故障保护措施提出了改进建议。通过工程实践,说明改进后的方案可在核电厂低压配电系统接地故障保护的设计中应用和推广。

According to the norms and standards,elaborate the design principles and stage difference coordination of earth fault protection in low voltage distribution system.Describe the typical schemes of earth fault protection in nuclear power plant.Detailed analysis and discussion are given out specific to the override trip accidents which are generated by earth fault.Based on the typical schemes,some improvement measures for earth fault protection design of low voltage distribution system in NPP are proposed.Popularization and effectiveness are verified through practical application in earth fault protection design of low voltage distribution system in one particular project.