低压配电盘保护配置改进方法研究  

Research on Improvement Method of Low Voltage Distribution Panel Protection Configuration

作　　者：李超群 李江[1] 李健 LI Chaoqun;LI Jiang;LI Jian(Suzhou Nuclear Power Research Institute,Suzhou 215000,China)

机构地区：[1]苏州热工研究院有限公司,江苏苏州215000

出　　处：《供用电》2021年第11期40-46,共7页Distribution & Utilization

基　　金：苏州热工研究院有限公司科技项目(R-2020SZSE21YF)。

摘　　要：当前国家标准、行业规范中通常以供电电缆末端金属性短路故障为前提,进行低压配电系统短路计算和保护配置分析。但实际工程实践表明,低压配电系统短路故障大多数情况下由供电回路非金属性接地向金属性接地短路、两相接地短路、三相短路逐步发展,电缆故障部位也存在不确定性。对于电机类供电回路,绕组内部为接地短路故障高发点。标准规范的设计前提与实际故障模式的偏差,可能导致低压配电系统保护配置失效,造成短路故障无法切除,甚至配电盘越级跳闸等后果。综合考虑上述各种因素,给出了配电盘全电流区间的配电盘越级跳闸和接触器触点熔焊粘连的风险分析方法。在此基础上,提取各级保护元件的特征参数,构建了一套系统公式化的保护配置改进方法,降低了保护失效导致的配电盘越级跳闸和接触器触点熔焊粘连的风险。The current national standards and industry specifications usually take the metallic short-circuit fault at the end of power supply cable as the premise,and carry out short-circuit calculation and protection configuration analysis of low-voltage distribution system.But the actual engineering practice shows that most of the short-circuit fault of low-voltage distribution system develops gradually from non-metallic grounding of power supply circuit to metallic grounding short-circuit,two-phase grounding short-circuit and three-phase short-circuit For the motor power supply circuit,the internal winding is the high incidence point of ground short circuit fault.The deviation between the design premise of the standard specification and the actual fault mode may lead to the failure of the protection configuration of the low-voltage distribution system,resulting in the failure of the removal of short-circuit fault,even the override trip of the distribution board.Considering the above-mentioned factors,the power supply risk analysis method of distribution board overstep tripping and contactor welding in the whole current range is given.On this basis,the characteristic parameters of all levels of protection elements are extracted,and a set of systematic formulaic protection configuration improvement method is constructed,which reduced risk of switchboard overstep tripping and contactor welding.

关 键 词：配电系统 非金属性接地 越级跳闸 保护配置 短路故障 

分 类 号：TM71[电气工程—电力系统及自动化]