穿心式电流互感器安装位置对电流测量精度的影响

Influence of Installation Location of the Straight-through Current Transformer on the Current Measurement Accuracy

为揭示穿心式电流互感器安装位置对电流测量精度的影响,基于法拉第电磁感应定律,分别生成了电缆与CT轴线平行及不平行两种情况下的绕组感应电流,通过对比两种情况下的电流值,建立了测量电流偏差率与电缆和CT轴线夹角间的关系方程,并给出了夹角在1°~20°间变化时CT测量电流偏差率。计算结果表明,当电缆与CT轴线夹角大于6°时,由CT安装位置产生的测量电流偏差率已高于5‰。

In order to reveal the influence of the installation position of the through-core current transformer on the current measurement accuracy,based on Faraday's law of electromagnetic induction,the induced currents of the windings are generated respectively when the cable and the CT axis are parallel and non-parallel.By comparing the current values in the two cases,the relationship equation between the measured current deviation rate and the angle between the cable and the CT axis is established,and the CT measurement current deviation rate when the angle changes between 1°and 20°.The calculation results show that when the angle between the cable and the CT axis is greater than 6°,the measured current deviation rate generated by the CT installation position is higher than 5‰.