直流输电用零磁通直流电流互感器的研制  

Development of a Zero-flux DC Current Transformer for HVDC Projects

作　　者：李鹤[1] 李前[1] 章述汉[1] 雷民[1] 李登云[1] 胡浩亮[1] 

机构地区：[1]中国电力科学研究院,武汉430074

出　　处：《高电压技术》2012年第11期2981-2985,共5页High Voltage Engineering

摘　　要：零磁通直流电流互感器被广泛应用于换流站中性线上直流电流的测量。为此,介绍了研制的1台3 000A/1V,50kV零磁通式直流电流互感器样机的工作原理、结构和性能指标。该直流电流互感器采用一对检测铁芯绕组作为一次和二次电流的安匝平衡检测器,由安匝平衡检测器控制的反馈功率放大器输出二次电流与一次电流达到磁势自平衡。设计的安匝不平衡造成误差约0.02%,且该分量对环境温度不敏感。分析认为主要的误差来源是位于控制室的负载电阻和放大电路。直流误差校准试验表明,该样机在额定持续热电流下的各点测量误差均<0.2%,在18kA下测量误差<0.3%。样机在短时电流试验和阶跃电流响应试验中表现出了良好的暂态性能。参考相关标准,样机通过了电磁兼容试验考核。该类型零磁通型直流电流互感器符合高压直流输电系统要求。Zero-flux DC current transformer has been widely used to measure DC current of neutral bus in convertor stations.We introduce the operation,structure,and performance of a 3 000A/1V,50kV,zero-flux DC current transformer prototype.The prototype uses a pair of detection cores and windings as an ampere-turn balance detector between the primary and secondary circuits.A feedback power amplifier,controlled by the ampere-turn balance detector,which outputs a secondary current,makes the prototype a self-balancing system.Error due to the ampereturn unbalance is about 0.02%,and is not sensitive to the ambient temperature.The largest error of the system comes from the load resistor and the amplifying circuits which are all located indoors.The prototype is verified by several DC accuracy tests,showing that the errors are less than 0.2%and 0.3%under the rated continuous thermal current and a large current of 18kA,respectively.In the short-time current tests and the step current response test,the prototype responds well to these currents.The prototype has also passed EMC tests according to related standards.It is concluded that the presented zero-flux DC current transformer fulfills the requirements of the HVDC transmission project.

关 键 词：高压直流输电 直流电流测量 零磁通 磁调制 误差 试验 

分 类 号：TM452[电气工程—电器]