宽频带交流电流精密测量关键技术研究

发布时间：2018-07-29 05:57

【摘要】：随着电子技术的飞速发展，对高频电流的计量校准需求日益增加。航空航天电子设备、军工产品中的运载工具、移动军事装备、航海装置等的电源系统均对重量和体积有着严格的要求。由于高频电流设备，尤其是大电流设备的体积小、重量轻、性能稳定可靠，新一代航空航天及军工产品的研制都倾向于使用高频电流系统提供电力。在高频冶炼、电力电子以及医学诊疗设备等方面，高频电流的使用也相当广泛。因此，建立宽频带的交流电流国家基准成为目前国际上研究的一个热点问题。各个国家的交流电流国家基准普遍是以交直流转换器为基础，然后采用爬台阶（Step-up）的方法实现各个量程交流电流的量值传递。交流电流溯源通常是以热电变换器10mA的有效值为起始点，然而大量的校准需求则是来自于1A以上乃至100A的高频电流信号，以爬台阶方法将10mA传递到1A需要经过多个步骤。国际上大部分国家建立的交流电流基准在高频100kHz时的电流上限只是10A或20A，，传递所积累的不确定度会随着电流的增加而越来越大。另外，高频下交直流差的电流系数是长期以来制约基准技术指标提高的重要因素，国际上目前也没有有效的测量和评定方法。本文提出并实现了一种与国际上完全不同的利用高频电流互感器建立宽频带交流电流国家基准的新方法；研制出新型宽频带交直流差可计算的同轴分流器，将交流电流的溯源起点由10mA提高到了1A；利用二进制电抗分流器和对高频电流互感器比例误差线性的评定，在国际上首次实现了分流器交直流差电流系数的绝对测量；采取电抗分流器进行交流电流的传递，避免了传递过程中由于分流器低端电位不一致造成的不确定性；通过电流系数的评定，结合电流互感器初次级间隔离的优势，改进了10mA到100A交流电流的传递方法，将传递步骤由国际上普遍采用的12步减少到4步，使得新建的高频大电流国家基准的技术指标大幅度提高。本文首先论述了国内外为使用交直流转换法建立交流电流国家基准方面的研究状况，分析和总结了方法中存在的问题，接下来研究了交直流差可计算同轴结构分流器和二进制电抗分流器的设计技术，建立了以1A电流为溯源起点的技术基础，然后研究了高频大电流互感器的同轴结构设计方法以及新的电流传递方法，随后研究了三种绝对测量分流器交直流差电流系数的方法，解决了国际上量程扩展中最大的不确定度分量的评定问题，最后对交流电流基准的测量能力进行了不确定度分析，通过旁证实验对测量方法进行了验证，保证了交流电流国家基准校准能力的可靠和等效。
[Abstract]:With the rapid development of electronic technology, the demand for measurement and calibration of high frequency current is increasing day by day. The power systems of aerospace electronic equipment, military products, mobile military equipment, navigation equipment and so on have strict requirements for weight and volume. Because of the small size, light weight, stable and reliable performance of high-frequency current equipment, especially high-current equipment, the development of new generation aerospace and military products tend to use high-frequency current system to provide power. High-frequency current is also widely used in high-frequency smelting, power electronics and medical diagnosis and treatment equipment. Therefore, the establishment of broad-band AC current national reference has become a hot issue in international research. The national reference of AC current in each country is based on AC / DC converter, and then the method of climbing step (Step-up) is used to realize the value transfer of AC current in each range. The starting point of AC current tracing is usually the effective value of 10mA of thermoelectric converter. However, a large number of calibration requirements come from high frequency current signals above 1A or even 100A. It takes many steps to transfer 10mA to 1A by climbing steps. The current upper limit of AC current reference established by most of the countries in the world is only 10A or 20A at high frequency 100kHz. The uncertainty of transmission accumulated will increase with the increase of current. In addition, the current coefficient of AC / DC difference at high frequency is an important factor that restricts the improvement of standard technical index for a long time, and there is no effective measurement and evaluation method in the world at present. In this paper, a new method of establishing the national reference of wide band AC current by using high frequency current transformer is proposed and realized, and a new type of coaxial shunt with computable AC / DC difference of wide band is developed. The traceability of AC current is improved from 10mA to 1A, and the absolute measurement of AC / DC current coefficient is realized for the first time in the world by using binary reactance shunt and linear evaluation of the proportional error of high frequency current transformer. The reactance shunt is adopted to transfer the AC current, which avoids the uncertainty caused by the inconsistency of the low-end potential of the shunt during the transfer process, and combines the advantages of the primary isolation of the current transformer with the evaluation of the current coefficient. The transmission method of AC current from 10mA to 100A is improved, and the transfer step is reduced from 12 steps to 4 steps, which greatly improves the technical index of the new high frequency and high current national reference. This paper first discusses the research status of establishing the national reference of AC / DC current in China and abroad, and analyzes and summarizes the problems existing in the method. Then, the design technology of AC / DC difference computable coaxial shunt and binary reactance shunt is studied, and the technical foundation of tracing the source of 1A current is established. Then, the design method of coaxial structure and new current transfer method of high frequency and large current transformer are studied, and then three methods of absolute measuring AC / DC differential current coefficient of shunt are studied. The evaluation of the largest uncertainty component in the international range expansion is solved. Finally, the uncertainty analysis of the measurement capability of the AC current reference is carried out, and the measurement method is verified by circumstantial experiments. It ensures the reliability and equivalence of the national reference calibration capability of AC current.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM933.1

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