超低频电压交直流转换关键参数分析  

Analysis on the key parameters of ac-dc transfer system for ultra-low frequency voltage

作　　者：石照民 张江涛[1] 潘仙林[1] 宋莹[1] Shi Zhaomin;Zhang Jiangtao;Pan Xianlin;Song Ying(National Institute of Metrology,China,Beijing 100029,China)

机构地区：[1]中国计量科学研究院,北京100029

出　　处：《仪器仪表学报》2020年第11期82-89,共8页Chinese Journal of Scientific Instrument

基　　金：国家重点研发计划(2016YFF0201204)项目资助。

摘　　要：为了实现超低频电压的溯源性,解决热电变换器无法满足10 Hz以下超低频电压交直流转换要求的问题,提出一种通过双加热丝热电变换器实现超低频电压交直流等效转换的方法,该方法主要基于双加热丝热电变换器输出热电势的平方特性和两路等幅值正交正弦信号的平方和恒等特性,通过在双加热丝热电变换器输入两路幅值相等且正交的低频电压信号,使热电变换器输出热电势保持稳定,消除热电变换器自身频率特性的影响。对影响热电变换器输出热电势稳定性的关键参数进行重点讨论,分析各参数的影响,设计评估实验分别对各关键参数进行评估补偿,建立超低频电压交直流转换系统,在0.1~10 Hz范围内交直流转换标准不确定度不超过20μV/V。In order to realize the traceability of the ultra-low frequency voltage and solve the problem that the thermal voltage converter(TVC) cannot meet the requirement of ac-dc transfer for ultra-low frequency voltage below 10 Hz, an ac-dc equivalent transfer method of ultra-low frequency voltage is proposed using the dual-heater TVC. The method is mainly based on the square characteristic of the output thermoelectric potential of the dual-heater TVC and the square sum identity characteristic of two quadrature sinusoidal signals with identical amplitude. Through inputting two low frequency quadrature voltage signals with identical amplitude to the dual-heater TVC, the output thermoelectric potential of the TVC is kept stable and the frequency characteristic influence of the TVC itself is eliminated. The paper mainly focuses on discussing the key parameters that affect the stability of the output thermoelectric potential of the TVC and analyzing the influence of various parameters. Evaluation experiments were designed to evaluate and compensite the influence of the key parameters respectively. A ultra-low frequency ac-dc transfer system was established, and the standard uncertainty of ac-dc transfer within the frequency ranges from 0.1~10 Hz does not exceed 20 μV/V.

关 键 词：超低频电压 交直流转换 关键参数 溯源性 双加热丝热电变换器 

分 类 号：TB97[一般工业技术—计量学] TH71[机械工程—测试计量技术及仪器]