基于反向晶闸管并联保护的变压器中性点直流电流抑制装置  

A Neutral DC Current Blocking Device for Grounding Transformer Based on Inverse Parallel Thyristors Protection

作　　者：王升[1,2] 陆继明[1] 毛承雄[1] 王丹[1] 梅桂华[3] 

机构地区：[1]华中科技大学电气与电子工程学院,武汉430074 [2]重庆市电力公司杨家坪供电局,重庆400080 [3]广东电网公司电力科学研究院,广州510600

出　　处：《电工技术学报》2010年第10期183-190,共8页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金资助项目(50977035)

摘　　要：针对直流输电单极大地回路运行方式下造成的接地变压器直流偏磁的问题,提出并研制了一种基于并联晶闸管保护的变压器中性点电容器隔直装置,分析了其拓扑结构和工作原理,由于不需要额外的整流回路和晶闸管关断回路,主回路的拓扑结构得以大量简化,降低了装置的成本,同时该装置采用了纯硬件的集成电路保护和微机保护的完全双重化冗余结构,提高了系统的可靠性和智能性。仿真结果、大电流试验情况和初步现场运行表明,该装置能有效解决由直流输电单极大地回路运行方式下造成的接地变压器直流偏磁的问题,具有很好的工程应用效果。When HVDC power system operates in ground return mode,the AC grounding transformers around the electrodes always suffer from DC biases due to the DC currents through their neutral points.In this paper,a novel transformer neutral DC current blocking device（NCBD） based on inverse parallel thyristors protection is proposed and developed to solve such problem.Based on the analysis of the topology and operating principles of NCBD,the main circuit is simplified by removing the front-end rectifier circuit and the turn-off circuit of thyristor.Thus,the cost of the device can be cut down a lot.Moreover,the reliability and intelligence of NCBD are improved by its dual redundant structure,which is made up of a set of hardware integrated circuit and a set of microcomputer measure-controlling system.Simulation results,high current tests and field operation results confirm that the NCBD can resolve the demand of DC bias restraint effectively,and provide a practical based engineering solution.

关 键 词：直流偏磁 高压直流输电 隔直装置 中性点 变压器 

分 类 号：TM85[电气工程—高电压与绝缘技术]