基于新型LVQB型电流互感器的CVT在线校验方法研究  

Investigate on On-line Calibrating Method for CVT by Using a New LVQB Type Current Transformer

作　　者：邵明鑫[1,2] 王晓琪[1,2] 吴细秀[3] 周纯[3] 汪本进[1,2] 杜砚[1,2] 

机构地区：[1]中国电力科学研究院 [2]国网高压电气设备运行性能评估实验室 [3]武汉理工大学

出　　处：《高压电器》2016年第8期45-51,共7页High Voltage Apparatus

基　　金：国家电网公司科技项目~~

摘　　要：目前CVT误差校验的主要方法为离线校验法,存在着校验工作量庞大以及校验结果偏离CVT在线状态下的实际值等问题。笔者提出了一种利用在运容性设备协助CVT进行在线校验误差的新方法。在变电站中大量使用的LVQB型电流互感器结构基础上,设计改造使其具备高压标准电容器功能,通过在其末屏接地线处串入低压标准电容器和电子分压器组成标准电容分压器,即可实现对CVT误差的在线校验。这种新型在线校验方法规避了在变电站在线直接投切标准电容分压器的风险,同时在完成对站内CVT的校验工作之后,恢复LVQB型电流互感器的正常接地,不影响LVQB型电流互感器的正常工作。随着该方法的大量应用,CVT的在线误差校验将取代繁琐的离线校验,同时也为下一步电力设备的在线检修奠定了基础。Off-line calibration is the main method for CVT error checking, which causes a lot of problems such as huge workload and the results deviate from the actual value of the CVT on-line running error. So a kind of new online calibration method is proposed in the paper with the help of running capacitive equipment. Based on the common structure of LVQB type current transformer, some changes are done to realize the function of high voltage standard capacitor. By untying the ground wire of reconstructed LVQB type current transformer and series connecting a low-voltage standard capacitor and a voltage divider, a standard capacitor voltage divider can be set up to become an on-line standard device so as to make the on-line calibration of CVT available. The new method avoids the risk of switching the standard capacitor voltage divider directly. When the error calibration work is finished, the ground wire is recovered so the LVQB type current transformer is an ordinary current transformer. With the applications of this method,the on-line error calibrating method will replace the traditional off-line method and provide the basis for on-line maintenance of electrical equipment.

关 键 词：电容式电压互感器 LVQB型电流互感器 在线校验 高压标准电容器 标准电容分压器 

分 类 号：TM45[电气工程—电器]