龙滩发电机主保护设计新思想

对龙滩发电机定子绕组分布结构进行了调研,查清了该发电机实际可能发生的相间、匝间短路故障数;应用“多回路分析法”深入、详尽地计算了13104种短路故障的全部分支电流的大小和相位。在此基础上,确定了龙滩发电机主保护的配置方案。该方案保护死区减小到0．183％(仅24种故障不能保护),99．51％的短路故障均有两套及以上不同原理的主保护灵敏动作(即仅有64种短路故障只有1套主保护动作或拒动);采用2／4出口跳闸方式,有效地降低了保护装置误动作率,使龙滩发电机主保护既具有高灵敏性、又具有高可靠性,这为特大型发电机主保护设计提供了新思想,创造了新经验。

New Idea of Generator Main Protection Design in Longtan Power Station

The distribution structure of generator stator winding in Longtan Power Station was investigated, the possible fault numbers of phase - to - phase and turn - to - turn short circuit were checked up. The phase and the size of all branch currents of the 13,104 kinds of fault of short circuit were calculated thoroughly thorough " mufti - bop analysis ". On this foundation, the disposition scheme of main protection of Longtan generator was determined. The protective dead band of the scheme reduces to 0.183% (only 24 kinds of fault can not protected), the 99.51% of short circuit fault of has two sets and above the main protection with different principles (only the 64 kinds of short circuit faults have 1 set of main protection). The mode of 2/4 outlet tripping adopted by the scheme can reduce the mal - operation rate of protection device efficiently, which make the main protection of Longtan generator high sensitivity and high reliability, and offer a new idea of main protection design for large generator.