扩大负荷法检测1000kV GIS中TA误差  

Application of Method of Increasing Burden on Error Calibration of 1000 kV GIS Current Transformer

作　　者：费烨[1] 吴士普[1] 李璿[1] 王晓琪[1] 

机构地区：[1]国网电力科学研究院,武汉430074

出　　处：《高电压技术》2008年第9期1862-1868,共7页High Voltage Engineering

基　　金："十一五"国家科技支撑计划重大项目(2006BAA02A11)~~

摘　　要：针对特高压GIS中TA额定一次电流大,试验回路长,采用直接法进行现场误差检测难度很大的问题,研究了适合特高压TA误差现场测量的新方法。考虑到特高压GIS中的TA处于对称安装方式,外磁场影响较小,基于TA的T型等效电路进行推导并探索采用一种误差间接法—扩大TA二次模拟负荷的方式,在较小的试验电流条件下外推大电流下的误差结果。1000kV TA实物进行直接法与间接法对比模拟验证试验的结果表明,比值和相位偏差分别只有0.002%和0.1′,完全在标准要求的偏差范围之内。因此,在1000kV工程中,采用扩大负荷法现场检测GIS中TA误差产生的差异可忽略不计,在现场特高压TA误差检测试验中可行。Test of error calibration of 1000 kV GIS Current Transformer is important of value source and relay protection in power measurement. The purpose of field error calibration test of Current Transformer is testifying phenomenon of error variability by transporting, installing and using. Method of traditional current transformer calibration is direct difference. So it is based on high current power. With voltage rank higher and higher,Field test is diffi cult for UHV CT because of high rated current and long circuit. For example, it needs 4200kvar capacity,which is condition of 6kA ratio current and 76mΩ circuit impedance. Even if adopting reactive compensation to supply a part of capacity,getting the capacity is hardly possible because experimentation cost is high. International experts in cur rent transformer field do a lot of research and propose some usefull suggestion. Internal experts such as ZHAO Xiuming come out some indirect method of error calibration. But there are some lack of these method. In order to discuss a compatible method of UHV CT in field error calibration test and considering of symmetry installment and low electromagnetic field, there is a indirect method based on equivalent T type circuit by increasing burden which gains error in high current though it in low condition. To prove the feasibility of this method, this paper launchs a simulative test by direct and indirect methods on UHV CT. The result shows that ratio error is only 0. 002 % and phase error is only 0.1＇. This result is not out extend of difference in GB 1208 -2007. In UHV engineering,error of 1000kV GIS Current Transformer with method of increasing burden is less difference. This method is feasible in field error calibration test of UHV Current Transformer.

关 键 词：1000 KV 电流互感器 误差测量 间接法 现场试验 扩大负荷 

分 类 号：TM452[电气工程—电器] TM835