核电厂主照明盘越级跳闸故障分析与改进

Analysis and Improvement of Trip Fault of Main Lighting Distribution Panelboards in Nuclear Power Plant

本文介绍了重水堆核电厂主照明盘越级跳闸问题,通过对照明回路保护配置分析,结合现场实际情况,得出了越级跳闸问题的原因,提出了对出线断路器进行配置剩余电流保护装置(RCD)的方法。根据解决方法,已成功实施了2#机组主照明盘保护配置的改进,验证了方法的可行性和有效性。通过保护改进,解决了原有主照明盘越级跳闸的问题,大大缩小了末级负荷接地故障的影响范围。

This paper introduces the override tripping problem of the main lighting distribution panelboards of heavy water reactor nuclear power plant.Through the analysis of the protection configuration of the lighting circuit and the actual situation on site,the causes of the override tripping problem are obtained,and the method of configuring residual current protective device(RCD)for the outgoing circuit breaker is put forward.According to the the solution,the improvement of the protection configuration of main lighting distribution panelboards has been successfully implemented in Unit 2 of nuclear power plant,which verifies the feasibility and effectiveness of the method.Through modification,the problem of overstep tripping of the main lighting distribution panelboards is solved,and the influence of grounding fault of the last stage load is greatly reduced.