发电机非同期合闸差动保护误动分析  

Analysis on Differential Protection Maloperation for Asynchronous Grid Connection of Generator

作　　者：聊方伦 周平 LIAO Fanglun;ZHOU Ping(Anhui Anqing Wojoint Power Generation Co.Ltd.,Anqing 246008,China;Zhejiang Zheneng Jiahua Power Generation Co.Ltd.,Pinghu 314201,China)

机构地区：[1]安庆皖江发电有限公司,安徽安庆246008 [2]浙能嘉华发电有限公司,浙江平湖314201

出　　处：《吉林电力》2020年第4期14-17,共4页Jilin Electric Power

摘　　要：针对300 MW单元制发电机-变压器组(以下简称发-变组)非同期合闸差动保护误动问题,分析了主变压器差动保护误动原因,是由于差流最小基波有效值大于制动后的最大动作电流导致,指出发电机非同期合闸对电流互感器励磁电流有影响,提出大型发-变组差动保护启动值应适当提高,二次谐波制动系数应适当降低的建议。Aiming at the maloperation of differential protection for 300 MW unit generator transformer unit with asynchronous closing,the cause of maloperation of differential protection of main transformer is analyzed,which is caused by the minimum effective value of differential current greater than the maximum operating current after braking.It is pointed out that the asynchronous closing of generator has influence on the excitation current of current transformer.It is suggested that the starting value of differential protection for large generator transformer unit should be increased appropriately,and the second harmonic braking coefficient should be appropriately reduced.

关 键 词：非同期合闸 主变压器 差动保护 误动 电流互感器 

分 类 号：TM762[电气工程—电力系统及自动化]