基于微分干扰补偿的新型电磁流量测量方法  

New electromagnetic flow measurement method based on differential interference compensation

作　　者：吴建平[1] 徐科军[1,2] 许伟[1] 汪春畅 于新龙 

机构地区：[1]合肥工业大学电气与自动化工程学院 [2]工业自动化安徽省工程技术研究中心

出　　处：《电子测量与仪器学报》2018年第9期117-123,共7页Journal of Electronic Measurement and Instrumentation

摘　　要：电磁流量计大多采用稳态励磁方案,励磁电流大,持续时间长,导致功耗很大,发热严重,影响其使用寿命。为了降低功耗,采用瞬态测量方法,通过研究瞬态时的信号模型,提出微分干扰补偿的处理方法,对信号电压进行微分干扰补偿,确定补偿后的电压除以励磁电流的结果与流量之间的关系。设计基于数字信号处理(DSP)的硬件,同步采集瞬态时的励磁电流和信号电压来验证该处理方法,离线数据处理表明,电压微分干扰补偿后的处理结果与流量有良好的线性关系。研制基于DSP的电磁流量变送器的软件,实时实现瞬态测量方法,进行水流量标定和功耗测试实验。实验结果表明,测量准确度达到0. 5%,与普通电磁流量计相同。功耗对比表明,基于瞬态测量原理的电磁流量计的励磁功耗是普通电磁流量计的1/1 200。Electromagnetic flowmeters mostly use a steady-state excitation scheme,the excitation current is large and the duration is long,which results in high power consumption and high heat generation to affect its service life. In order to reduce power consumption,a transient measurement method is used. By studying the transient signal model,a differential interference compensation method is proposed,and the signal voltage is subjected to differential interference compensation,then the relationship between the compensated voltage divided by the current and the flow rate is determined. In order to verify the measurement method,a digital signal processing( DSP)-based hardware is designed,and the excitation current and signal voltage of the transient process are acquired. Processing of offline data shows that there is a good linear relationship between processing result and flow rate. The software of electromagnetic flow transmitter based on DSP is developed,the transient measurement method is realized in real-time so as to perform the water flow calibration and power consumption test experiments. The experimental results show that the measurement accuracy is 0. 5% which is same as the ordinary electromagnetic flowmeter. Comparisons of power consumption show that excitation power consumption of electromagnetic based on transient measurement principle is 1/1 200 of the ordinary.

关 键 词：电磁流量计 瞬态测量 微分干扰补偿 功耗 

分 类 号：TH814.93[机械工程—仪器科学与技术]