| 引用本文: | 赵丽娟,梁若愚,徐志钮,赵海英,陈永辉,郭一帆.沿线布里渊频移大范围波动下分布式光纤传感扫频范围选择及误差估算[J].电力自动化设备,2021,41(4): |
| ZHAO Lijuan,LIANG Ruoyu,XU Zhiniu,ZHAO Haiying,CHEN Yonghui,GUO Yifan.Frequency sweep span selection in optical fiber distributed sensor with large Brillouin frequency shift variation and its error estimation[J].Electric Power Automation Equipment,2021,41(4): |
|
| 摘要: |
| 为了提高光纤沿线大的布里渊频移波动情况下基于布里渊散射的分布式光纤传感的准确性，基于实测220 kV光纤复合架空地线中光纤沿线的布里渊谱展示了此时扫频范围选择的困境。基于数值产生布里渊谱和实测布里渊谱研究了不对称的扫频范围对布里渊频移误差的影响，发现如果较短侧扫频范围不小于ΔvB，则扫频范围偏差对谱拟合算法算得的布里渊频移的准确性没有明显影响，此时布里渊频移误差与对称情况下的布里渊频移误差近似相等。基于大量数值产生布里渊谱计算获得考虑不同扫频范围、扫频点数、信噪比和线宽下布里渊频移误差的估算公式，并采用不同信噪比、扫频范围、扫频点数、线宽及扫频范围对称与否时的实测布里渊谱进行了验证，结果表明估算公式的误差约为8 %。研究工作为提高光纤沿线布里渊频移大范围波动情况下基于布里渊散射的分布式光纤传感的准确性和温度、应变测量误差的估算奠定了基础。 |
| 关键词: 分布式光纤传感器 布里渊散射 扫频范围不对称 扫频范围选择 误差估算 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目(51607066,61377088)；河北省自然科学基金资助项目(E2019502177, E2020502010)；中央高校基本科研业务费专项资金资助项目(2019MS085) |
|
| Frequency sweep span selection in optical fiber distributed sensor with large Brillouin frequency shift variation and its error estimation |
|
ZHAO Lijuan1,2, LIANG Ruoyu1, XU Zhiniu1, ZHAO Haiying1, CHEN Yonghui3, GUO Yifan1
|
|
1.School of Electrical and Electronic Engineering, North China Electric Power University, Baoding 071003, China;2.Hebei Key Laboratory of Power Internet of Things Technology, North China Electric Power University, Baoding 071003, China;3.Science & Technology College, North China Electric Power University, Baoding 071003, China
|
| Abstract: |
| To improve the accuracy of optical fiber distributed sensor based on Brillouin scattering when the Brillouin frequency shift varies significantly along the optical fiber, the dilemma about how to select frequency sweep span in that case is demonstrated according to the measured Brillouin spectra along an optical fiber composite overhead ground wire with a voltage level of 220 kV. The influence of asymmetry of frequency sweep span on the Brillouin frequency shift error based on the numerically generated and measured Brillouin spectra is investigated. The results reveal that if the frequency sweep span of short side of spectrum is not less than ΔvB, then the deviation of frequency sweep span has no obvious influence on the Brillouin frequency shift error, and the Brillouin frequency shift error is approximately equal to the Brillouin frequency shift error in the case of symmetrical frequency sweep span. Based on a large number of numerically generated Brillouin spectra and the pseudo-Voigt model-based spectrum fitting algorithm, a Brillouin frequency shift error estimation formula considering different values of frequency sweep span, number of sweeps, signal-to-noise ratio and linewidth is proposed, which is validated by use of the measured spectra with different values of signal-to-noise ratio, frequency sweep span, number of sweeps, linewidth and symmetrical and asymmetrical frequency sweep span. The results reveal that the error of the estimation formula is about 8 %. This work lays a foundation for improving accuracy of optical fiber distributed sensor based on Brillouin scattering and error estimation of measured temperature and strain when the Brillouin frequency shift varies significantly along the optical fiber. |
| Key words: optical fiber distributed sensor Brillouin scattering asymmetrical frequency sweep span frequency sweep span selection error estimation |
