大型汽轮发电机绕组同槽同相调查及保护方案定量化设计

大型汽轮发电机实际存在定子绕组匝间短路,不装设匝间短路保护是发电机安全运行的严重隐患.文中以2台300 MW汽轮发电机主保护配置方案的定量化设计为例,说明保护人员应与业主、电机制造厂家密切配合,争取汽轮发电机中性点侧引出2个中性点并装设分支电流互感器,为装设横差保护和不完全纵差保护提供可能,从而对发电机的安全运行提供高质量的保证.

INVESTIGATION OF TURN-TO-TURN FAULT RATIO AND QUANTITATIVE DESIGN OF MAIN PROTECTION CONFIGURATION SCHEME FOR LARGE-SIZED TURBO-GENERATOR

Owing to existence of the turn-to-turn fault of a large-sized turbo-generator stator winding in practice, harmful results will be caused without the turn-to-turn short-circuit protection in the operational mode. The turn-to-turn fault ratio of large-sized turbo-generators at home and abroad are reviewed. By the quantitative design of the main protection configuration scheme for two 300 MW turbo-generators, the necessity of leading out two neutral points and installing the branch current transformer at the neutral-point side of a turbo-generator are planned. And high quality protection performances can be supplied by the transverse differential protection and incomplete longitudinal differential protection for the large-sized turbo-generator. To implement above configurations in practice need fully efforts of relay engineers, owners and machinery workers.