单官伟

[摘    要]  对某沿海地区发电工程一起封闭母线安装原因引起发电机组跳机事故调查分析，论述其主要原因为封闭母线软连接板质量有缺陷、安装工艺不符合规范要求、质量验收把关不严，导致封闭母线软连接板部分过热熔毁，形成短路接地引起发电机组跳机。建议加强施工工艺管控，采取相应的预防措施，提高封闭母线安装安装合格率，保障发电机组安全、可靠运行。

[关键词]封闭母线安装;发电机组;跳机事故;调查分析

[中图分类号]TM595 [文献标志码]A [文章编号]2095–6487（2021）11–0–02

Investigation and Analysis of a Generator Trip

Accident Caused by Closed Bus Installation

Shan guan-wei

[Abstract]An investigation and analysis of a generator trip accident caused by the installation of a closed busbar in a coastal area power generation project. The main reasons are the defective quality of the closed busbar flexible connecting plate， the installation process does not meet the specification requirements， and the quality acceptance check is not strict. The soft connecting plate of the closed bus is overheated and melted， forming a short circuit and grounding and causing the generator set to trip. It is recommended to strengthen the construction process control and take corresponding preventive measures to increase the qualified rate of the closed bus installation and to ensure the safe and reliable operation of the generator set.

[Keywords]closed bus installation; generator set; trip accident; investigation and analysis

1 事故概况

某沿海地区新建工程2×1 000 MW超超临界二次再热燃煤发电机组，两台机组均采用发电机—变压器组单元接线，经主变压器升压至500 kV后接入厂内新建的500 kV配电装置，再接入500 kV系统。发电机出口不设断路器或负荷开关，发电机与主变压器采用全连式离相封闭母线相连接。

3号机组在运行过程中发生一起发电机跳闸事故：发变组保护A屏、B屏发电机定子零序电压保护动作跳闸，主变高压侧500 kV开关7A1、7AB1跳闸，发电机励磁开关跳闸，厂用6 kV 3A段工作进线开关跳闸，厂用6 kV 3B段工作进线开关跳闸，脱硫及公用6 kV工作电源段馈线开关跳闸，厂用6 kV 3A、3B段和脱硫及公用6 kV快切装置启动切换成功，同时关闭汽机主汽门，汽机跳闸，机组MFT动作跳闸。集控中心运行值班人员通知调试、安装单位的相关人员进行事故排查分析，发现发电机出线A相离相封闭母线与主变连接处发生接地故障。

2 事故调查

2.1 引起跳闸的事故发……