互易低压外推法在现场大电流检定中的应用探讨

Discussion on the Application of Low Voltage Extrapolation Technique on Calibrating High Current Transformer

为验证互易低压外推法在现场大电流检定中的可行性,从传统比较法的测量原理介绍和大电流互感器所需升流器容量计算出发,分析传统比较法存在的问题。最后采用电流互感器现场校验仪和传统电流互感器标准装置分别对准确度等级为0.2级、额定电流比为2000A/5A和5000A/5A的电流互感器进行试验,试验结果表明:采用互易低压外推法和传统比较法对同一电流互感器进行试验时,最大差值还不到误差限值的1/5。可见,互易低压外推法在现场大电流检定中具有一定的推广价值。

To verify the feasibility of low voltage extrapolation using in high current transformer test at the scene, this paper analyzes the problems existing in the traditional comparison method under giving the measuring principle of traditional comparison method and the capacity needed in the test. Finally, the two different method used in calibrating current transformer which accuracy is 0.2, ratio is 2000 A / 5 A and 5000 A / 5A. The calibration result shows that the data low voltage extrapolation given was similar to the results testing by traditional comparison method. Low voltage extrapolation is accurate and reliable in the high current verification.