基于串联电容法的变压器中性点直流电流抑制装置  

Application of a Series Capacitor Based Transformer Neutral DC Current Blocking Device

作　　者：张金平[1] 张辉[1] 熊敏[1] 张丽坤[1] 程春和[1] 

机构地区：[1]中国电力科学研究院,北京市海淀区100192

出　　处：《电网技术》2009年第20期147-151,共5页Power System Technology

摘　　要：潖江变1号变压器中性点直流电流抑制装置采用在变压器中性点串联电容器阻断直流电流的方案,且电容器并联了由快速开关、整流桥、大功率晶闸管、过电压触发单元、快速脱扣回路等组成的快速旁路系统。文章介绍了该装置的工作原理,叙述了贵广Ⅱ回直流试验期间该装置的动作情况,并讨论了主变中性点安装隔直装置对相邻变压器中性点的影响,试验及运行数据表明,装置能有效抑制变压器中性点直流电流。The scheme of adopting the capacitor connected in series with transformer neutral to block DC current is used to the transformer neutral DC current blocking device for No.1 power transformer of Pajiang substation, while the capacitor is connected in parallel with fast by-pass system consisting of fast switch, rectifier bridge, high-power thyristors, overvoltage-triggering unit and fast-tripping circuit. This device can withstand fault current of 20 kA with duration of 1 second, and its standard impedance is less than 1.2 W, the trigger time of the by-pass system is shorter than 20ms, meanwhile, the monitoring and control unit make the operation of the device visible, controllable and operable. The action of this device during the testing period of the No.2 circuit of HVDC power transmission project from Guizhou to Guangdong is described in detail, and impacts of configuring DC current blocking device in the neutral of No.1 power transformer of Pajiang substation on neutrals of adjacent power transformers are analyzed. Both test results and operation data show that this device works normally and can effectively block DC current in transformer neutral.

关 键 词：串联电容法 变压器中性点直流电流抑制装置 旁路系统 单极大地运行方式 

分 类 号：TM772[电气工程—电力系统及自动化]