【摘要】 记述了某电厂一台300MW发电机组运行中母线保护动作造成的发电机停机事故。分析了事故起因,确定是误操作和误整定两个因素共同作用导致。进一步阐明了事故中继电保护的动作情况及原理,并对发变组保护功能是否受到影响,为什么母线保护先于发变组保护动作以及厂用电切换方式三个问题进行了说明。提出了纠正继电保护定值设置的具体方案,明确了制定针对运行中更换发电机出口PT一次保险的安全、技术措施的必要性,以避免类似事故的发生。更多还原

【Abstract】 The paper describes an accident of bus protection acting which made a running 300 MW generator shut down.It analyzes the accident and points out it is the coacting of incorrect manipulation and incorrect setting that causes the accident.Furthermore,it clarifies the mechanism of related relay action and explains the following three issues,including whether the function of generator-transformer unit protection is influenced,why does the bus protection act before the generator-transformer unit protection,and auxiliary power switching mode.At last,a solution to reset the setting value is proposed and the necessity of replacing the primary fuse of generator outlet side PT is emphasized to avoid similar accident.更多还原