特高压直流保护动作策略优化  

Optimization of UHVDC Protection Action Strategy

作　　者：赵森林[1] 卢亚军[2] 吕鹏飞[3] 阮思烨 张建锋[1] 刘凯[1] 冯宇[4] 

机构地区：[1]南京南瑞继保电气有限公司,江苏南京211102 [2]国网北京经济技术研究院,北京102209 [3]国家电力调度通信中心,北京100031 [4]中国电力科学研究院,湖北武汉430074

出　　处：《电力工程技术》2017年第4期143-149,共7页Electric Power Engineering Technology

摘　　要：特高压直流输送容量大,一极停运对两端交流系统的冲击很大,且导致单极大地回线运行,很大的入地直流电流对交流系统及附近的金属件产生不利影响,尤其对在运的换流变以及换流站近端的变压器产生直流偏磁,威胁换流变及变压器的安全运行。文中对特高压直流保护中的换流器差动保护、接地极线过负荷保护、接地极线不平衡保护以及线路重启逻辑的动作策略进行了优化,可大大缩短上述保护动作一极闭锁后单极大地回线运行的时间,减少流入大地的直流电流对交流系统、金属件、换流变及变压器的影响;并针对接地极引线增加了接地极线差动保护和接地极线差动监视报警功能,提高了接地极线的保护水平。文中的策略已应用于哈郑、灵绍直流工程,现场试验效果良好。UHVDC transmission capacity is large, there will be a great impact on both sides of connecting ac system while one pole is outage,leading another pole in monopolar ground circuit operation mode. At this time the high amplitude dc current flowing into ground will have negative effects on the AC system and the metal parts nearby, producing DC magnetic biasing in converter transformers in operation and transformers nearby, threatening the safety operation of converter transformers and other transformers. Optimizations of the protection strategy in UHVDC including the converter differential protection, the grounding electrode line overload protection, the grounding electrode line unbalance protection and line fault restart logic is described in this paper, extremely shortening the operation time of the monopolar ground circuit operation mode after action of above protections, reducing influence of DC current flowing into the earth on the AC system,metal parts, converter transformers and other transformers. In order to improve the electrode line protection level, the grounding electrode line differential protection and supervision are added. These strategies have been applied in Hami-Zhengzhou UHVDC project and Linzhou-Shaoxin UHVDC project, the result of field test is effective and good.

关 键 词：特高压直流输电 保护优化 重启逻辑 接地极线保护 

分 类 号：TM723[电气工程—电力系统及自动化]