摘要
设计了SF_6分解气多参数综合监测平台,选择多频正弦调制方法研发了基于FPGA的多通道锁相放大电路,并对多通道锁相放大原理进行了理论推导,提出一种多频调制信号的频率分配原则。搭建针对多组分气体的多参数综合监测平台,给出温度、压强、微水、SF_6纯度等传感器的集成方案。实验结果表明,本系统平台能够从较低浓度的H_2S、HF、CO混合气体中正确解调出二次谐波信号,不同气体的二次谐波之间干扰性较小,对弱吸收的CO气体信号提高2个数量级,实现了多组分微量气体的同时监测。
The paper designs a multi-parameter comprehensive monitoring platform for SF6 decomposition gases.Multichannel lock-in amplifier circuits with multi-frequency modulation method is used in FPGA system.In this issue,the multichannel lock-in amplifier theories are presented in details,and one kind of frequency allocation principle of multi-frequency modulation signals is proposed.The sensor integration method of temperature,pressure,water vapor and the SF6 purity is utilized through establishing the multi-parameter comprehensive monitoring platform for mixed gases.The experimental results indicate that the device developed in this paper could demodulate the second harmonic signals correctly from fewer mixed gases included H2S,HF and CO.These signals have smaller disturbance among different second harmonics.In addition,the signal of CO that has weaker absorption coefficient is amplified 100 times.Thus,the on-line monitoring technique at the same time for multi-component fewer gases is realized.
出处
《导航与控制》
2017年第3期74-78,共5页
Navigation and Control
基金
国家电网公司科技项目(编号:524625160030)
关键词
多频正弦调制
FPGA
锁相放大电路
二次谐波
在线监测
multi-frequency modulation
FPGA
lock-in amplifying circuit
second harmonic
on-line monitoring
