消除容性泄漏的双激励高阻抗测量研究  

Research on double excitation high impedance measurement to eliminate capacitive leakage

作　　者：王选择[1,2] 蔡玉雄 李煜辰 王浩伟 WANG Xuanze;CAI Yuxiong;LI Yuchen;WANG Haowei(School of Mechanical and Engineering,Hubei University of Technology,Wuhan 710068,China;Hubei Key Laboratory of Modern Manufacturing Quality Engineering,Wuhan 710068,China;Aviation Key Laboratory of Science and Technology on Structural Corrosion Protection and Control,China Special Aircraft Research Institute,Jingmen 448035,China)

机构地区：[1]湖北工业大学机械工程学院,湖北武汉430068 [2]湖北省现代制造质量工程重点实验室,湖北武汉430068 [3]中国特种飞行器研究所结构腐蚀防护与控制航天科技重点实验室,湖北荆门448035

出　　处：《华中科技大学学报（自然科学版）》2024年第9期149-155,164,共8页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(32071457);武汉市重点研发计划资助项目(2022012202015034)。

摘　　要：交流阻抗测量中,运算放大器本身输入阻抗的存在导致容性泄漏,影响被测阻抗的准确性,且被测阻抗越高,容性泄漏对测量精度的影响越大.为此,针对高阻抗测量,提出了一种利用两步激励法同时获取运放输入阻抗与被测阻抗的测量方法,并根据得到的被测阻抗值进行电桥双激励平衡的粗调整及所设计的增量迭代法进行电桥平衡的精调整,实现高阻抗的高精度测量.实验选择交流激励频率为1 kHz,参考阻抗固定为1 MΩ,被测阻抗在0.010~100 MΩ测量范围内,所得测量结果的阻抗模的相对标准偏差优于0.028%,相位角标准偏差优于0.8mrad.且当被测阻抗与参考阻抗接近时,阻抗模相对标准偏差达到0.003%的水平.In AC(alternating current) impedance measurement,the existence of input impedance of Op-Amp(Operational amplifier) will lead to capacitive leakage and affect the accuracy of measured impedance.And the higher the measured impedance,the greater the impact of capacitive leakage on the measurement accuracy.Therefore,for high impedance measurement,a measurement method using two-step excitation method to simultaneously obtain the input impedance of the operational amplifier and measured impedance was proposed.According to the measured impedance value,the double excitation balance of the bridge was rough adjusted,and the incremental iteration method was designed to precise adjust the bridge balance.The high-precision measurement of high impedance was realized.The experiment selected an AC frequency of 1 kHz for excitation,a fixed reference impedance of 1 MΩ,and a measured impedance within the measurement range of 0.010~100 MΩ.The measurement results show that the RSD(relative standard deviation) of impedance modulus is better than 0.028%,and the SD(standard deviation) of phase angle is better than 0.8 mrad.And the relative standard deviation of the impedance modulus reaches the level of 0.003% when the measured impedance is close to the reference impedance.

关 键 词：交流电桥 高阻抗测量 容性泄漏 两步激励法 增量迭代法 

分 类 号：TM934.1[电气工程—电力电子与电力传动]