自平衡式交直流电流比较仪研究

为满足日益提高的宽频电流测量需求,文章设计研制了一种自平衡式交直流电流比较仪。该交直流电流比较仪在磁调制式直流电流比较仪的基础上引入闭环交流测量通道,不仅极大地拓展了其测量的频带宽度,而且利用反馈技术实现了电流比较仪的自动平衡。详细介绍了电流比较仪的研制过程,并搭建虚拟仪器自动测试系统对所研制电流比较仪的性能进行考察。测量结果表明,该交直流电流比较仪在直流测量时的线性误差小于2×10-4,交流测量带宽不低于100k Hz,测量标准不确定度为2×10-5。

The Development of Self-balancing AC and DC Current Comparator

This paper develops a self-balancing AC and DC current comparator for meeting the growing demand of wideband current measurement. The AC and DC current comparator is built up on the basis of magnetic modulation-based direct current comparator and a closed-loop alternative measurement channel has been added. The new design can not only expand the measuring band width, but also make the current comparator self-balanced. The development process has been described in detail and an automatic measuring system based on virtual instrument control has been set up to test measurement performance of the current comparator. The measuring results show that its DC linear error is below 2×10-4, AC measurement bandwidth is no less than 100kHz, and standard measurement uncertainty is 2×10-5.