广州换流站换流变压器差动保护附加闭锁功能浅析  

Analysis of additional block functions of converter transformer’s differential protection serving in Guangzhou converter station

作　　者：李书勇[1] 张海凤[1] 张鹏[1] 汲广[1] 毛海鹏[1] 

机构地区：[1]中国南方电网超高压输电公司广州局,广东广州510405

出　　处：《电力系统保护与控制》2008年第22期93-96,107,共5页Power System Protection and Control

摘　　要：换流变压器网侧绕组出现励磁涌流或过激磁电流时,如果换流变压器保护装置的差动保护逻辑没有被可靠闭锁,该装置可能误动作。文章介绍广州换流站换流变压器保护装置KBCH130和7UT513的差动保护动作特性,阐述它们针对励磁涌流和过激磁电流设置的附加闭锁功能;就广州换流站同期装置PSD(Point on Wave Switching Device)运行异常情况下,对一次极1换流变压器充电过程中发生的KBCH130差动保护动作情况进行分析,基于磁通的变化原理估算涌流最小间断时间,用西门子波形分析软件SIGRA4.21分析涌流波形间断情况,结果认为KBCH130设置的间断角定值过大,对应的间断角附加闭锁功能失效而引起此次差动保护误动作。When magnetizing inrush current or excitation current occurs at the primary winding of the converter transformer, its relays would make a wrong tripping action unless the differential protection functions are blocked reliably. The differential protection characteristics of its protection devices KBCH 130 and 7UT 513 are introduced in this paper, and the additional block functions aiming at inrush current and excitation current are expatiated in detail. What＇s more, while the Guangzhou station＇s PSD （Point on Wave Switching Device） works abnormally, one differential protection tripping event taking place when the converter transformers of pole one switched on has been analyzed. Minimum gap time of the inrush current is evaluated based on the changing of flux, and the waveform is analyzed with the software SIGRA 4.21 of SIEMENS. The conclusion is proposed like this： the failed additional block function of the dead angle resulted in the mistaken tripping action for the setting value of the dead angle is too large.

关 键 词：励磁涌流 过激磁电流 差动保护 KBCH1 换流变压器 广州 换流站 

分 类 号：TM772[电气工程—电力系统及自动化]