直流电流比较仪解调方式的研究  

Research on the demodulation methods of DC current comparator

作　　者：周力任[1] 朱力[1] 潘洋[1] Zhou Liren;Zhu Li;Pan Yang(Shanghai Institute of Measurement and Testing Technology,Shanghai 201203,China)

机构地区：[1]上海市计量测试技术研究院

出　　处：《电测与仪表》2020年第3期148-152,共5页Electrical Measurement & Instrumentation

基　　金：国家质量监督检验检疫总局资助项目(2016QK117)

摘　　要：为提升直流电流比较仪的灵敏度和准确度、降低噪声,对其关键环节解调方式开展研究。阐述直流电流比较仪两种解调方式的工作原理,设计相应的电路并搭建仿真模型。结果表明,两种解调方式都能实现将检测绕组输出信号转换为对应直流电压的功能。峰差解调的重要优点是能解调出所有的偶次谐波信号,从而获得很高的检波增益,有利于提高灵敏度和准确度。但二次电流的纹波较大。相敏解调的窄带特性有利于减小系统的噪声电平,二次电流的纹波很小。由于只解调二次谐波,需满足最佳条件才能达到高灵敏度。In order to improve the sensitivity and accuracy and reduce the noise of DC current comparator,the key link demodulation method was researched.This paper describes the working principle of two demodulation methods of DC current comparator,designs the corresponding circuit and builds the simulation model.The result shows that both methods can realize the function of converting the output signal of detection winding to the corresponding DC voltage.The advantage of peak difference demodulation is that it can demodulate all even harmonic signals.A high detection gain will be obtained accordingly,which is favorable to improve sensitivity and accuracy.But the ripple of secondary current is large.Narrow band characteristics of phase sensitive demodulation are beneficial for reducing the system noise level,and the ripple of secondary current is very small.As only the second harmonics are demodulated,it is necessary to satisfy the best condition to achieve high sensitivity.

关 键 词：直流电流比较仪 相敏解调 峰差解调 谐波 

分 类 号：TM276[一般工业技术—材料科学与工程]