基于回线型结构的大电流精确测量装置

Large current precision measurement device based on the loop structure

本文设计了一种适用于测量航空电磁发射机发射电流的大电流采样电阻装置,在测量航空电磁发射机发射电流时,为了减小PWM控制策略及外部环境造成的干扰影响,需要一种零电抗的采样分流电阻。对奥地利国家计量院BEV和加拿大NRC联合研制的套筒型大电流分流器进行了改进研究。用有限元分析法计算了回线型结构电阻的电感与结构的关系,并且实际制作了该结构的4种样品,进行了实际测量;证明了有限元方法得出结论的正确性,并最终确定了一种采样电阻的尺寸。测试结果表明,与过去采用的直板型采样电阻结构相比,失真度提高了一个数量级。同时此测量结构还适用于其他快速变化大电流的测量场合。

A large current sampling resistor is designed for measuring the airborne electromagnetic transmitter emission current of the large current sampling resistance device. When the airborne electromagnetic transmitter current is measured,a kind of zero reactance shunt resistor sampling is required to reduce the interference effect of PWM control strategy and external environment. The improvement for the sleeve type high current shunt jointly developed by the Austrian National Metrology Institute of BEV and NRC Canada[1]is analyzed. The relationship between the inductance and the structure of the resistance of loop structure is calculated with the finite element analysis method,and the actual production of 4 kinds of samples are fabricated. The practical measurement has been done,and the correctness of the finite element method is proved. Finally the size of the sampling resistance is determined. Experimental results show that,compared with the straight type sampling resistor structure,the distortion is improved by one order of magnitude. At the same time,the structure is also suitable for other fast and large current measurement occasions.