智能站变压器小区差动保护异常的分析与处理  

Analysis and Treatment of Abnormal Limit Zone Differential Protection for Intelligent Station Transformers

作　　者：倪赛赛[1] 刘科 崔力心[1] 

机构地区：[1]国网甘肃省电力公司电力科学研究院,甘肃兰州730050 [2]中国能源建设集团甘肃省电力设计院有限公司,甘肃兰州730050

出　　处：《电气自动化》2016年第2期84-86,共3页Electrical Automation

基　　金：国网甘肃省电力公司科技项目(522722140045)

摘　　要：750 k V电压等级变压器为提高差动保护的灵敏度,配套有分相差动与低压侧小区差动保护相结合的保护类型,不仅能解决纵联差动保护的转角问题,而且可以大幅提高低压侧故障的灵敏度。在某750 k V变压器启动过程中,两套主变保护低压侧小区差动均出现了异常差流,导致启动过程被迫停止。通过查阅设计图纸和现场接线,解决了设计错误造成电流重复转角计算的问题,PRS-778T保护装置恢复正常。通过分析主变本体合并单元延时,解决了由于额定延时设置不一致造成存在相位差的问题,最终WBH-801T保护装置异常消除。To improve the sensitivity of its differential protection,750 k V level transformers are provided with phase segregated differential protection combined with limit zone differential protection for low-voltage side to solve the problem of rotation angle in longitudinal differential protection and to significantly raise the sensitivity of low-voltage side faults as well. In the start-up process of a 750 k V transformer,an abnormal differential flow appears in the limit zone differential protection for low-voltage side of both main transformers,resulting in a forced suspension of the starting process. By consulting design drawings and field wiring,we solved the problem of repeated calculation of current rotation angle as a design error,and PRS-778 T protection device was restored to its normal operation. After analyzing the time delay of the emerging unit of the main transformer proper,we solved the problem of phase difference attributable to inconsistent setting of rated time delay,and finally eliminated the abnormality with WBH-801 T protection device.

关 键 词：分相差动保护 低压侧小区差动保护 自耦变压器 合并单元 额定延时 转角计算 

分 类 号：TM41[电气工程—电器]