1000MW发电机变压器组保护配置探讨  

Study of 1000 MW generator-transformer unit protection configuration

作　　者：周建[1] 周卫巍[2] 王锋[2] 

机构地区：[1]山东电力工程咨询院有限公司,山东济南250013 [2]国核电力规划设计研究院,北京100094

出　　处：《电力系统保护与控制》2010年第11期126-129,146,共5页Power System Protection and Control

摘　　要：某电厂1000MW机组主变压器采用三台单相变压器,变压器纵差保护在接地故障发生时灵敏度偏低;常规的基波零序电压和三次谐波电压式定子接地保护,其三次谐波含量受发电机运行状态影响,不能满足在发电机运转前先投入定子接地保护的要求。应用短路电流计算结果和发电机变压器回路的对地电容值,通过整定变压器零序差动保护,选择与注入式定子接地保护相配合的发电机中性点接地电阻,分析了零序差动保护和注入式定子接地保护在设计中应该注意的问题。提出了主变压器增加零序差动保护、定子接地采用基波零序电压和三次谐波电压式与注入式两套不同原理保护的方案。A 1 000 MW power plant uses three single-phase transformers as the generator-transformer（GT）.The transformer differential relay＇s sensitivity is low when earthed.The stator earth fault relay is based on fundamental voltage and third hamonic voltage measurement.The third hamonic component is influneced by the generator operation mode,so the earth relay cannot work properly before the generator operates.Using the short results and the GT-ground capacitor,the transformer zero-sequence differential relay is set,the generator neutral resistor matched with injection method stator earth fault relay is selected.The concerned problems in the design of zero-sequence differential relay and injection method stator earth relay are analyzed.Two protection schemes are put forward,i.e.the GT zero-sequence differential relay and the stator earth fault relay using the fundamental voltage and third hamonic voltage measurement method and the injection method.

关 键 词：零序差动保护 定子接地保护 基波零序电压和三次谐波电压式 注入式 

分 类 号：TM774[电气工程—电力系统及自动化]