CN112666083A - SF based on Raman spectrum6Decomposition gas detection enhancement system - Google Patents
SF based on Raman spectrum6Decomposition gas detection enhancement system Download PDFInfo
- Publication number
- CN112666083A CN112666083A CN202110004009.XA CN202110004009A CN112666083A CN 112666083 A CN112666083 A CN 112666083A CN 202110004009 A CN202110004009 A CN 202110004009A CN 112666083 A CN112666083 A CN 112666083A
- Authority
- CN
- China
- Prior art keywords
- laser
- optical signal
- circuit
- cavity
- signal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000001069 Raman spectroscopy Methods 0.000 title claims description 22
- 238000001514 detection method Methods 0.000 title abstract description 27
- 230000003287 optical effect Effects 0.000 claims abstract description 99
- 238000012545 processing Methods 0.000 claims abstract description 51
- 238000001237 Raman spectrum Methods 0.000 claims abstract description 23
- 230000003321 amplification Effects 0.000 claims abstract description 22
- 238000003199 nucleic acid amplification method Methods 0.000 claims abstract description 22
- 238000000354 decomposition reaction Methods 0.000 claims abstract description 17
- 239000000523 sample Substances 0.000 claims abstract description 14
- 238000006243 chemical reaction Methods 0.000 claims abstract description 11
- 230000005540 biological transmission Effects 0.000 claims abstract description 10
- 238000000034 method Methods 0.000 claims abstract description 9
- 230000002708 enhancing effect Effects 0.000 claims abstract description 5
- 230000003014 reinforcing effect Effects 0.000 claims abstract 9
- 230000003595 spectral effect Effects 0.000 claims description 19
- 238000002347 injection Methods 0.000 claims description 11
- 239000007924 injection Substances 0.000 claims description 11
- 238000001228 spectrum Methods 0.000 claims description 8
- 230000009471 action Effects 0.000 claims description 6
- 230000005855 radiation Effects 0.000 claims description 6
- 238000002310 reflectometry Methods 0.000 claims description 6
- 238000001914 filtration Methods 0.000 claims description 4
- 230000001965 increasing effect Effects 0.000 claims description 4
- 238000002834 transmittance Methods 0.000 claims description 4
- 230000008878 coupling Effects 0.000 claims description 3
- 238000010168 coupling process Methods 0.000 claims description 3
- 238000005859 coupling reaction Methods 0.000 claims description 3
- 230000005684 electric field Effects 0.000 claims description 3
- 230000008030 elimination Effects 0.000 claims description 3
- 238000003379 elimination reaction Methods 0.000 claims description 3
- 230000010363 phase shift Effects 0.000 claims description 3
- 230000008859 change Effects 0.000 claims description 2
- 230000003993 interaction Effects 0.000 claims description 2
- 238000012544 monitoring process Methods 0.000 claims description 2
- 238000011084 recovery Methods 0.000 claims description 2
- 238000012216 screening Methods 0.000 claims description 2
- 230000006870 function Effects 0.000 claims 1
- 238000005516 engineering process Methods 0.000 abstract description 5
- 238000003745 diagnosis Methods 0.000 abstract description 4
- 230000008569 process Effects 0.000 abstract description 3
- 239000007789 gas Substances 0.000 abstract 4
- 238000004458 analytical method Methods 0.000 abstract 1
- 229910018503 SF6 Inorganic materials 0.000 description 12
- 238000009413 insulation Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000004817 gas chromatography Methods 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- SFZCNBIFKDRMGX-UHFFFAOYSA-N sulfur hexafluoride Chemical compound FS(F)(F)(F)(F)F SFZCNBIFKDRMGX-UHFFFAOYSA-N 0.000 description 3
- 238000004566 IR spectroscopy Methods 0.000 description 2
- 230000032683 aging Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 206010063385 Intellectualisation Diseases 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000001626 infrared photoacoustic spectroscopy Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 239000012774 insulation material Substances 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000004445 quantitative analysis Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 229960000909 sulfur hexafluoride Drugs 0.000 description 1
- OBTWBSRJZRCYQV-UHFFFAOYSA-N sulfuryl difluoride Chemical compound FS(F)(=O)=O OBTWBSRJZRCYQV-UHFFFAOYSA-N 0.000 description 1
- LSJNBGSOIVSBBR-UHFFFAOYSA-N thionyl fluoride Chemical compound FS(F)=O LSJNBGSOIVSBBR-UHFFFAOYSA-N 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Images
Landscapes
- Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
Abstract
The invention relates to SF based on Raman spectrum6Decomposition gas detection reinforcing system belongs to power equipment fault diagnosis detection field. The system comprises: the Raman spectrum transmission and receiving module, the optical signal acquisition module, the optical signal processing module, the data processing module and the upper computer; the Raman spectrum emission and receiving module comprises a probe array, an electromagnetic wave emission driving circuit and an optical signal echo processing circuit; the optical signal acquisition module comprises a signal amplification circuit and a filter circuit; the optical signal processing module comprises an optical signal denoising channel, an optical signal cavity enhancing channel and a frequency phase-locked loop; the data processing module comprises a digital-to-analog conversion circuit, an operational amplification circuit and a basic storage circuit. The invention adopts Raman spectrum technology to detect SF6The decomposition gas system can simultaneously detect multiple decomposition gases by using the laser with the same wavelength without specially processing the gas sample to be detected, and has the advantages of rapid analysis process and dry resistanceStrong interference capability and good detection repeatability.
Description
The invention belongs to the field of power equipment fault diagnosis and detection, and relates to SF (sulfur hexafluoride) based on Raman spectrum6A decomposition gas detection enhancement system.
Background
With the steady promotion of the economy and the quality of life of the nation, the scale of the intelligent power grid is gradually enlarged, so that the requirements on the power supply quality and the safe and reliable operation of the power grid are higher and higher. With SF6Gas insulation equipment (gas insulation combined electrical equipment, gas insulation transformers, gas insulation lines and the like) with gas as an insulation and arc extinguishing medium is important high-voltage electrical equipment in a power system, plays a very important role in the power transmission and transformation processes of the power system, and is particularly important for the safety and stability of the power system in terms of safe and reliable operation. With the continuous development of national economy, the power grid scale is continuously enlarged, and SF6The number of gas insulated electrical devices is increasing day by day, and once a fault occurs, not only is the equipment asset lost, but also large-scale power failure can be caused, and huge losses are caused to the people's life, the national economy and the like. Thus, SF is improved6The operation level of the gas insulated electrical equipment enhances the early latent fault diagnosis capability of the electrical equipment, and finds the latent fault type as soon as possible, thereby having important significance for ensuring the safe operation of the power grid. SF due to manufacturing, installation, shipping and handling defects6The gas insulated switchgear has inevitable discharge and overheat failure inside, resulting in SF6The gas is decomposed and SO is generated2F2、SOF2、CF4、SO2、H2S, CO and CO2And the like, characteristic gas components reflecting the type of insulation defects, the discharge level and the degree of aging of the insulation material inside the device. For SF6 gasAnd decomposition characteristic components thereof are effectively detected, so that the aging degree of the insulating material in the equipment and the internal pressure condition of the GIS (gas insulated switchgear) can be accurately diagnosed, and the diagnosis result can be SF6The gas insulated switchgear has the advantages that the gas insulated switchgear provides a basis for the whole life cycle management, and is one of key problems of improving the utilization rate of equipment, reducing the overhaul cost of the equipment, improving the operation and maintenance intellectualization of the equipment and ensuring the safe production of a power grid.
Current power industry to SF6The detection method of the decomposed gas is also based on infrared spectroscopy and gas chromatography, and Chinese patent CN102445433A discloses SF based on infrared photoacoustic spectroscopy6An on-line gas concentration measuring device for a decomposed gas. CN110132891A discloses a SF detection method based on multi-dimensional gas chromatography6And (4) a decomposition product full-component device.
The existing technical scheme can carry out primary detection on the decomposition product of the transformer oil by a certain method, but the gas chromatography is easily interfered by environmental factors such as temperature and the like, and can generate certain influence on the detection result, and the infrared spectroscopy has weak light source intensity and low measurement precision.
Disclosure of Invention
In view of the above, the present invention provides an SF based on Raman spectroscopy6A decomposition gas detection enhancement system.
In order to achieve the purpose, the invention provides the following technical scheme:
SF based on Raman spectrum6The decomposed gas detection enhancement system is based on the enhancement of an optical feedback frequency-locked cavity to SF6Detecting the decomposed gas;
the system comprises: the Raman spectrum transmission and receiving module, the optical signal acquisition module, the optical signal processing module, the data processing module and the upper computer;
the Raman spectrum transmitting and receiving module comprises a probe array, an electromagnetic wave transmitting drive circuit and an optical signal echo processing circuit;
the optical signal acquisition module comprises a signal amplification circuit and a filter circuit;
the optical signal processing module comprises an optical signal denoising channel, an optical signal cavity enhancing channel and a frequency phase-locked loop;
the data processing module comprises a digital-to-analog conversion circuit, an operational amplification circuit and a basic storage circuit;
the Raman spectrum transmitting and receiving module is in signal connection with the optical signal acquisition module; the optical signal acquisition module is in signal connection with the optical signal processing module; the optical signal processing module is in signal connection with the data processing module; the data processing module is in signal connection with an upper computer;
the probe array is respectively in signal connection with the electromagnetic wave emission driving circuit and the optical signal echo processing circuit;
the signal amplification circuit is respectively in signal connection with the filter circuit, the electromagnetic wave emission driving circuit and the optical signal echo processing circuit;
the filter circuit is in signal connection with the optical signal denoising channel;
the optical signal denoising channel is in signal connection with the optical signal cavity enhancement channel;
the optical signal cavity enhanced channel is in signal connection with the frequency phase-locked loop;
the frequency phase-locked loop is in signal connection with the digital-to-analog conversion circuit;
the digital-to-analog conversion circuit is in signal connection with the operational amplification circuit;
the operational amplifier circuit is in signal connection with the basic memory circuit.
Optionally, the raman spectrum emission receiving module realizes emission and recovery of a raman spectrum voltage signal, and specifically includes:
the emission driving circuit generates square wave pulse signals with different frequencies and drives the probe array to emit electromagnetic wave signals, the probe array mutually converts electromagnetic waves and spectrum signals, and the echo processing circuit conducts primary filtering and amplification processing on the spectrum signals and then transmits the spectrum signals to the optical signal acquisition module.
Optionally, the optical signal acquisition module realizes acquisition and processing of the optical echo signal, specifically:
the signal amplification circuit amplifies signals transmitted back by the probe array, the filter circuit filters interference signals of various other frequencies in echo waves, and the accurate optical signal analog quantity is obtained and then transmitted to the optical signal processing module.
Optionally, the optical signal processing module first implements noise elimination on the spectral signal processed by the optical signal acquisition module through the spectral signal denoising channel, then enters the frequency phase-locked loop after the intensity of the raman scattering optical signal is improved through the optical signal cavity enhancement channel, performs distance and phase deviation judgment on the enhanced spectral signal according to the frequency phase-locked loop setting, and outputs the spectral control analog signal to the data processing module.
Optionally, the data processing module converts the spectral analog quantity into a digital signal through a digital-to-analog conversion circuit, and transmits the digital signal to the operational amplification circuit for amplification and operational processing and storing in the basic storage circuit.
Optionally, the upper computer module is used for implementing instruction operation, parameter setting, real-time monitoring of data change, spectrogram display and data interaction with the embedded system.
Optionally, optical feedback is defined as the return of laser light injected into the optical cavity to the laser after a delay time;
the optical feedback frequency locking means that laser emitted by a master laser is injected into the laser, and the frequency and the phase of the master laser are copied to a slave laser;
the locking method comprises the following specific steps:
s1, firstly, injecting laser radiation provided by a laser source into a Fabry-Perot cavity with high fineness, screening out laser radiation with the frequency completely same as that of a resonant cavity, and feeding back laser beams output by the cavity to the laser source;
s2, copying laser output by the master laser with the same frequency as the resonant frequency to the slave laser according to the light injection locking;
s3, finally, generating laser power in the cavity under the action of constructive interference;
under the optical feedback frequency locking condition, the laser coupling output laser frequency is expressed as:
wherein, ω isfree＝πcN/ηLdIs the free running power of the laser, c is the speed of light, eta is the dielectric loss, LdIs the laser cavity length, k is POF/PLasFor feedback of light injection locking, POFFor feedback of optical power, PLasIs the power of the incident laser light, FP＝πr0/(1-r0 2) Is the laser quality factor, Fd＝πr2/(1-r4) Is the quality factor of the V-type resonant cavity, r0Is the end face reflectivity of the laser, r is the specular reflectivity of the V-shaped resonant cavity, L0Is the optical distance between the laser and the V-type resonant cavity, L1、L2The length of the V-shaped resonant cavity arm is theta (arctan (alpha)), and alpha is a line width gain factor.
Optionally, the step of enhancing the optical feedback frequency locking cavity specifically includes:
the distance between the parallel lenses M1 and M2 forming the F-P cavity is set as L, and the reflection coefficient of M1 is set as
Electric field transmission coefficient of
R1And T1Respectively, M1, and a reflection coefficient of M2
Electric field transmission coefficient of
R2And T2The transmittance and reflectance of M2, respectively, are R1+T1＝1，R2+T2＝1；
A beam of light with frequency of omega, wave vector of k-omega/c-2 pi/lambda and electric field vector of Ein is incident on M1, part of the light is transmitted to M2, and the rest of the light is reflected by M1; the light projected to M2 is partially reflected back to M1, and the rest is transmitted out of the resonant cavity; part of the light reflected to M1 is reflected back to M2, and the rest is transmitted out of the resonant cavity;
when the light waves propagate in the cavity, phase shift is generated, interference among a plurality of reflected light beams is long, and the power of laser in the cavity is increased; order to
The total transmitted light amplitude is then expressed as:
wherein phi is-2 omega L/C, transmitted light intensity IT＝|ET|2Substituting T-1-R, the transmitted light intensity is expressed as:
is provided with
The transmitted light intensity is equal to the incident light intensity up to a maximum.
The invention has the beneficial effects that: the optical feedback frequency cavity enhancement detection technology can receive 3 spectral signals with different frequencies, collect the spectral signals, acquire spectral frequency speed and attenuation coefficient parameters through noise processing of the collected spectral signals, improve gas Raman scattering intensity by adopting the optical feedback frequency locking cavity enhancement technology, and the Raman enhancement multiple experimental value reaches more than 150 times. The interference of an external environment on a detection result is avoided to the greatest extent, the Raman characteristic frequency shift spectral line of each gas is confirmed, the minimum detection limit of each gas is calculated, and compared with the prior art, the experimental time and the experimental cost are saved.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the means of the instrumentalities and combinations particularly pointed out hereinafter.
Drawings
For the purposes of promoting a better understanding of the objects, aspects and advantages of the invention, reference will now be made to the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a system diagram of optical feedback frequency-locked cavity enhancement;
FIG. 2 is a flow chart of an optical feedback frequency-locked cavity enhanced detection system;
FIG. 3 is a schematic diagram of multi-beam interference of a resonant cavity;
FIG. 4 is a schematic diagram of multi-beam interference of a resonant cavity;
fig. 5 is a cavity output signal.
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention in a schematic way, and the features in the following embodiments and examples may be combined with each other without conflict.
Wherein the showings are for the purpose of illustrating the invention only and not for the purpose of limiting the same, and in which there is shown by way of illustration only and not in the drawings in which there is no intention to limit the invention thereto; to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.
The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar components; in the description of the present invention, it should be understood that if there is an orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", etc., based on the orientation or positional relationship shown in the drawings, it is only for convenience of description and simplification of description, but it is not an indication or suggestion that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes, and are not to be construed as limiting the present invention, and the specific meaning of the terms may be understood by those skilled in the art according to specific situations.
Please refer to fig. 1-5, which illustrate a raman spectroscopy based SF6A decomposition gas detection enhancement system.
The enhancement principle of the Raman spectrum optical feedback frequency locking cavity is as follows:
the cavity enhancement technology forms interference through multiple refraction and reflection to simultaneously improve an action path and laser action power so as to improve Raman scattering intensity, so that the minimum detection limit of gas is improved, and detection of trace gas is realized. In order to realize interference, the cavity length of the enhanced cavity needs to be equal to integral multiple of half wavelength of the output laser source, namely the output frequency needs to be stably locked with the resonant frequency of the enhanced cavity. The detection SF of the optical feedback frequency locking cavity enhanced Raman spectrum is researched on the basis of the cavity enhancement principle and the frequency locking principle6A system for decomposing a gas content.
Cavity enhancement and frequency locking principle
The phenomenon that the laser light injected into the optical cavity returns to the laser after a certain time delay is called optical feedback. Optical feedback frequency locking is a frequency locking technique based on injection locking. The basic principle of injection locking is that the laser light from the master laser is injected into the laser and the frequency and phase of the master laser is replicated into the slave laser.
Assuming that the distance between the parallel mirror plates M1 and M2 constituting the F-P cavity is L, the reflection coefficient of M1 is
Electric field transmission coefficient of
(R1And T1Transmittance and reflectance of M1, respectively), M2 has a reflectance of
Electric field transmission coefficient of
(R2And T2Transmittance and reflectance of M2, respectively), then there is R1+T1＝1，R2+T 21. The enhancement principle is shown in fig. 3. A beam of light with frequency omega, wave vector k-omega/c-2 pi/lambda and electric field vector Ein is incident on M1, part of the light is transmitted to M2, and the rest of the light is reflected by M1; the light projected to M2 is partially reflected back to M1, and the rest is transmitted out of the resonant cavity; part of the light reflected to M1 is reflected back to M2, the rest being transmitted out of the cavity. When the light wave propagates in the cavity, phase shift is generated, interference among a plurality of reflected light beams is long, and the power of the laser in the cavity is increased. Order to
The total transmitted light amplitude can be expressed as equation 1:
wherein phi is-2 omega L/C, transmitted light intensity IT＝|ET|2Substituting T-1-R, the transmitted light intensity can be expressed as:
in the formula 2, when
When is at time
(q is an integer)) The transmitted light intensity is equal to the incident light intensity reaching a maximum. Namely when
When the cavity length is integral multiple of half wavelength, standing wave is formed in the cavity, and the maximum value of the transmitted light appears.
In practice, the cavity length changes slightly due to the influence of temperature, mechanical waves, and the like, and it is difficult to maintain the structural interference condition for a long time, and therefore a constant frequency locking technique is required to maintain the structural interference condition.
The phenomenon that the laser light injected into the optical cavity returns to the laser after a certain time delay is called optical feedback. Optical feedback frequency locking is a frequency locking technique based on injection locking. The basic principle of injection locking is that the laser light from the master laser is injected into the laser and the frequency and phase of the master laser is replicated into the slave laser.
The principle is shown in fig. 4: the laser radiation provided by the laser source is first injected into a high-finesse Fabry-Perot cavity. Only laser radiation having exactly the same frequency as the resonator frequency can be created and present in the resonator. The cavity output laser beam will be fed back to the laser source. Laser light output from the master laser having exactly the same frequency as the resonance frequency is copied to the slave laser (laser light source) according to the optical injection locking. Finally, under the action of constructive interference, a large laser power is generated in the cavity.
Under the optical feedback frequency locking condition, the laser coupling output laser frequency can be expressed as:
wherein, ω isfree＝πcN/ηLdIs the free running power of the laser (c is the speed of light, eta is the dielectric loss, L)dIs the laser cavity length), k is PoF/PLasInjection locking (P) for feedback lightOFFor feedback of optical power, PLasAs incident light laser power), FP＝πr0(1-r0 2) For laser qualityFactor, Fd＝πr2/(1-r4) Is a V-type resonant cavity quality factor (r)0Reflectivity of laser end face, r is reflectivity of V-type resonant cavity mirror), L0Is the optical distance between the laser and the V-type resonant cavity, L1、L2And the arm length of the V-shaped resonant cavity is equal to arctan (alpha) (alpha is a line width gain factor). Equation 3.3 shows that under certain experimental equipment conditions, the laser coupling-out laser frequency depends on the optical distance L0、L1And L2And feedback light injection efficiency k.
As shown in figures 1 and 2, when the system works, firstly, the Raman spectrum electromagnetic wave emission driving circuit generates electromagnetic wave signals with different frequencies, and the emission probe array is respectively excited to emit a plurality of ultrasonic electromagnetic wave signals with different frequencies to pass through SF6Decomposing the gas, and passing the electromagnetic wave signal through SF6After the gas is decomposed, the Raman spectrum receiving probe array receives optical signals, and the optical signal echo processing channel can carry out primary filtering and amplification processing on the optical spectrum signals; a signal amplification circuit in the optical signal processing module further amplifies the processed data such as the spectral signal and the like and then transmits the amplified data to a filtering processing circuit, and after interference signals of other frequencies are filtered, the accurate spectral signal is transmitted to a spectral signal denoising channel for noise elimination; the cavity enhancement module reflects the denoised optical signal in the cavity for multiple times to form constructive interference, so that the laser power and the effective action length in the cavity are improved, and the intensity of Raman scattering optical signals is improved; the frequency phase-locked loop judges the distance and phase deviation of the enhanced optical signal according to the setting requirement and outputs a control analog signal to the digital-to-analog conversion circuit, and the digital-to-analog conversion circuit converts the Raman spectrum analog quantity into a digital signal and then transmits the digital signal to the operational amplification circuit for amplification and operational processing and then stores the digital signal in the basic storage circuit; the upper computer analyzes and calculates the phase deviation and the peak locking effect after the display correlation processing, determines whether the feedback phase is optimal or not through the graph of the cavity output signal graph 5, and when the feedback phase is optimal, the curves of the images are symmetrical; when the feedback phase is wrong, the output phase is asymmetric, and the asymmetric degree can reflect the deviation process of the feedback phaseAnd comparing the detection result with the detection result which is not enhanced, and verifying the enhancement effect of the cavity enhancement technology on the Raman scattering. By measuring the Raman intensities under different pressures or laser powers, the influence rules of different detection conditions on the cavity enhanced Raman spectroscopy gas detection can be explored, the optimal experimental conditions are determined, and a quantitative analysis model is established. For SF6、CF4、SO2、SO2F2、CO2And carrying out cavity-enhanced Raman spectrum detection on the mixed gas such as COS (COS), confirming Raman characteristic frequency shift spectral lines of each gas, and calculating the minimum detection limit of each gas.
Finally, the above embodiments are only intended to illustrate the technical solutions of the present invention and not to limit the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions, and all of them should be covered by the claims of the present invention.
Claims (8)
1. SF based on Raman spectrum6Decomposition gas detects reinforcing system, its characterized in that: the system is based on optical feedback frequency locking cavity enhancement to SF6Detecting the decomposed gas;
the system comprises: the Raman spectrum transmission and receiving module, the optical signal acquisition module, the optical signal processing module, the data processing module and the upper computer;
the Raman spectrum transmitting and receiving module comprises a probe array, an electromagnetic wave transmitting drive circuit and an optical signal echo processing circuit;
the optical signal acquisition module comprises a signal amplification circuit and a filter circuit;
the optical signal processing module comprises an optical signal denoising channel, an optical signal cavity enhancing channel and a frequency phase-locked loop;
the data processing module comprises a digital-to-analog conversion circuit, an operational amplification circuit and a basic storage circuit;
the Raman spectrum transmitting and receiving module is in signal connection with the optical signal acquisition module; the optical signal acquisition module is in signal connection with the optical signal processing module; the optical signal processing module is in signal connection with the data processing module; the data processing module is in signal connection with an upper computer;
the probe array is respectively in signal connection with the electromagnetic wave emission driving circuit and the optical signal echo processing circuit;
the signal amplification circuit is respectively in signal connection with the filter circuit, the electromagnetic wave emission driving circuit and the optical signal echo processing circuit;
the filter circuit is in signal connection with the optical signal denoising channel;
the optical signal denoising channel is in signal connection with the optical signal cavity enhancement channel;
the optical signal cavity enhanced channel is in signal connection with the frequency phase-locked loop;
the frequency phase-locked loop is in signal connection with the digital-to-analog conversion circuit;
the digital-to-analog conversion circuit is in signal connection with the operational amplification circuit;
the operational amplifier circuit is in signal connection with the basic memory circuit.
2. SF according to claim 1 based on Raman spectroscopy6Decomposition gas detects reinforcing system, its characterized in that: the Raman spectrum emission receiving module realizes emission and recovery of Raman spectrum voltage signals, and specifically comprises the following steps:
the emission driving circuit generates square wave pulse signals with different frequencies and drives the probe array to emit electromagnetic wave signals, the probe array mutually converts electromagnetic waves and spectrum signals, and the echo processing circuit conducts primary filtering and amplification processing on the spectrum signals and then transmits the spectrum signals to the optical signal acquisition module.
3. SF according to claim 1 based on Raman spectroscopy6Decomposition gas detects reinforcing system, its characterized in that: the optical signal acquisition module realizes acquisition and processing of optical echo signals, and specifically comprises:
the signal amplification circuit amplifies signals transmitted back by the probe array, the filter circuit filters interference signals of various other frequencies in echo waves, and the accurate optical signal analog quantity is obtained and then transmitted to the optical signal processing module.
4. SF according to claim 1 based on Raman spectroscopy6Decomposition gas detects reinforcing system, its characterized in that: the optical signal processing module firstly realizes noise elimination on the spectral signal processed by the optical signal acquisition module through the spectral signal denoising channel, then the spectral signal enters the frequency phase-locked loop after the intensity of the Raman scattering optical signal is improved through the optical signal cavity enhancing channel, distance and phase deviation judgment is carried out on the enhanced spectral signal according to the frequency phase-locked loop, and a spectral control analog signal is output to the data processing module.
5. SF according to claim 1 based on Raman spectroscopy6Decomposition gas detects reinforcing system, its characterized in that: the data processing module converts the spectrum analog quantity into a digital signal through the digital-to-analog conversion circuit, transmits the digital signal to the operational amplification circuit for amplification operation processing and stores the digital signal in the basic storage circuit.
6. SF according to claim 1 based on Raman spectroscopy6Decomposition gas detects reinforcing system, its characterized in that: the upper computer module is used for realizing the functions of instruction operation, parameter setting, real-time data change monitoring, spectrogram display and data interaction with the embedded system.
7. SF according to claim 1 based on Raman spectroscopy6Decomposition gas detects reinforcing system, its characterized in that:
the optical feedback is defined as that laser light injected into the optical resonant cavity returns to the laser after a delay time;
the optical feedback frequency locking means that laser emitted by a master laser is injected into the laser, and the frequency and the phase of the master laser are copied to a slave laser;
the locking method comprises the following specific steps:
s1, firstly, injecting laser radiation provided by a laser source into a Fabry-Perot cavity with high fineness, screening out laser radiation with the frequency completely same as that of a resonant cavity, and feeding back laser beams output by the cavity to the laser source;
s2, copying laser output by the master laser with the same frequency as the resonant frequency to the slave laser according to the light injection locking;
s3, finally, generating laser power in the cavity under the action of constructive interference;
under the optical feedback frequency locking condition, the laser coupling output laser frequency is expressed as:
wherein, ω isfree＝πcN/ηLdIs the free running power of the laser, c is the speed of light, eta is the dielectric loss, LdIs the laser cavity length, k is POF/PLasFor feedback of light injection locking, POFFor feedback of optical power, PLasIs the power of the incident laser light, FP＝πr0/(1-r0 2) Is the laser quality factor, Fd＝πr2/(1-r4) Is the quality factor of the V-type resonant cavity, r0Is the end face reflectivity of the laser, r is the specular reflectivity of the V-shaped resonant cavity, L0Is the optical distance between the laser and the V-type resonant cavity, L1、L2The length of the V-shaped resonant cavity arm is theta (arctan (alpha)), and alpha is a line width gain factor.
8. SF according to claim 1 based on Raman spectroscopy6Decomposition gas detects reinforcing system, its characterized in that: the optical feedback frequency locking cavity enhancement specifically comprises the following steps:
parallel lenses M1 and M1 for forming F-P cavityDistance between M2 is L, and reflection coefficient of M1 is
Electric field transmission coefficient of
R1And T1Respectively, M1, and a reflection coefficient of M2
Electric field transmission coefficient of
R2And T2The transmittance and reflectance of M2, respectively, are R1+T1＝1,R2+T2＝1；
A beam of light with frequency of omega, wave vector of k-omega/c-2 pi/lambda and electric field vector of Ein is incident on M1, part of the light is transmitted to M2, and the rest of the light is reflected by M1; the light projected to M2 is partially reflected back to M1, and the rest is transmitted out of the resonant cavity; part of the light reflected to M1 is reflected back to M2, and the rest is transmitted out of the resonant cavity;
when the light waves propagate in the cavity, phase shift is generated, interference among a plurality of reflected light beams is long, and the power of laser in the cavity is increased; order to
The total transmitted light amplitude is then expressed as:
wherein phi is-2 omega L/C, transmitted light intensity Ir＝|ET|2Substituting T-1-R, the transmitted light intensity is expressed as:
is provided with
The transmitted light intensity is equal to the incident light intensity up to a maximum.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110004009.XA CN112666083A (en) | 2021-01-04 | 2021-01-04 | SF based on Raman spectrum6Decomposition gas detection enhancement system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110004009.XA CN112666083A (en) | 2021-01-04 | 2021-01-04 | SF based on Raman spectrum6Decomposition gas detection enhancement system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112666083A true CN112666083A (en) | 2021-04-16 |
Family
ID=75412655
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110004009.XA Pending CN112666083A (en) | 2021-01-04 | 2021-01-04 | SF based on Raman spectrum6Decomposition gas detection enhancement system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112666083A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113588568A (en) * | 2021-06-21 | 2021-11-02 | 南方电网科学研究院有限责任公司 | Method for detecting environment-friendly insulating gas decomposition product |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20120039346A1 (en) * | 2010-08-10 | 2012-02-16 | Oewaves, Inc. | Feedback-enhanced self-Injection locking of lasers to optical resonators |
| US9110006B1 (en) * | 2014-06-19 | 2015-08-18 | Southwest Sciences Incorporated | Frequency-feedback cavity enhanced spectrometer |
| CN106990091A (en) * | 2017-04-13 | 2017-07-28 | 重庆大学 | Frequency Locking V-type for gas Raman spectral detection signal enhancing strengthens chamber |
| CN109580585A (en) * | 2019-01-07 | 2019-04-05 | 重庆大学 | Characteristic of transformer gas Raman spectrum detection device and detection method |
-
2021
- 2021-01-04 CN CN202110004009.XA patent/CN112666083A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20120039346A1 (en) * | 2010-08-10 | 2012-02-16 | Oewaves, Inc. | Feedback-enhanced self-Injection locking of lasers to optical resonators |
| US9110006B1 (en) * | 2014-06-19 | 2015-08-18 | Southwest Sciences Incorporated | Frequency-feedback cavity enhanced spectrometer |
| CN106990091A (en) * | 2017-04-13 | 2017-07-28 | 重庆大学 | Frequency Locking V-type for gas Raman spectral detection signal enhancing strengthens chamber |
| CN109580585A (en) * | 2019-01-07 | 2019-04-05 | 重庆大学 | Characteristic of transformer gas Raman spectrum detection device and detection method |
Non-Patent Citations (3)
| Title |
|---|
| J. MORVILLE ET AL.: "Fast, low-noise, mode-by-mode, cavity-enhanced absorption spectroscopy by diode-laser self-locking", APPL. PHYS. B, vol. 80, pages 1031 - 1032 * |
| 万福: "变压器油中溶解气体光反馈 V 型腔增强吸收光谱检测研究", 中国博士学位论文全文数据库（电子期刊）, no. 6, pages 68 - 69 * |
| 万福等: "变压器油中气体拉曼光谱检测及信号处理方法", 仪器仪表学报, vol. 37, no. 11, pages 2482 - 2488 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113588568A (en) * | 2021-06-21 | 2021-11-02 | 南方电网科学研究院有限责任公司 | Method for detecting environment-friendly insulating gas decomposition product |
| CN113588568B (en) * | 2021-06-21 | 2022-10-28 | 南方电网科学研究院有限责任公司 | Method for detecting environment-friendly insulating gas decomposition product |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11300499B2 (en) | Multi-cavity semi-open resonant photoacoustic cell and multi-gas simultaneous measurement system | |
| CN109655446B (en) | Triangular resonant cavity/integrating sphere combined enhancement cavity for improving gas Raman intensity | |
| CN112525841B (en) | Vibration and gas temperature concentration measuring method based on ring-down cavity | |
| US20220228977A1 (en) | Detection method and detection device for trace gas | |
| CN113433072A (en) | Gas concentration sensor and gas concentration detection device | |
| CN104931427A (en) | Opto-acoustic gas detection device based on multiple reflections of optical path | |
| CN114136921A (en) | Laser photoacoustic spectrum gas detection device and method based on acousto-optic frequency shift and frequency locking technology | |
| CN105466854A (en) | Active air-chamber structure and photoacoustic spectrometry gas sensing system | |
| US10876958B2 (en) | Gas-detecting device with very high sensitivity based on a Helmholtz resonator | |
| CN112666083A (en) | SF based on Raman spectrum6Decomposition gas detection enhancement system | |
| CN114047136A (en) | High-sensitivity combined light source type photoacoustic spectroscopy multi-component gas detection system and method | |
| CN113008829A (en) | Near-infrared linear cavity enhanced absorption spectrum device based on optical feedback | |
| CN113155742A (en) | Single resonant cavity photoacoustic spectroscopy system and method for simultaneously detecting multiple gases | |
| CN105043996A (en) | Spectral measurement method of spectrograph | |
| Zhao et al. | All-optical photoacoustic detection of SF6 decomposition component SO2 based on fiber-coupled UV-LED | |
| Cheng et al. | The effect of the photoacoustic Field-Photoacoustic cell coupling term on the performance of the gas detection system | |
| CN112710628A (en) | Ultra-sensitive SF (sulfur hexafluoride) based on broadband double-optical-comb spectrum6Gas decomposition component detection method | |
| CN211347908U (en) | Transformer oil gas monitoring system based on semiconductor laser | |
| Li et al. | Highly sensitive near-infrared gas sensor system using a novel H-type resonance-enhanced multi-pass photoacoustic cell | |
| CN209495963U (en) | A kind of infrared photoacoustic spectra detection system | |
| CN115561195A (en) | Single-cavity double-comb light source and gas detection system based on same | |
| CN113655414B (en) | Optical magnetic field sensing system using piezoelectric ceramics to generate resonance frequency band | |
| CN215574610U (en) | Single resonant cavity photoacoustic spectroscopy system for simultaneously detecting multiple gases | |
| CN114609047A (en) | Photoacoustic spectroscopy multi-component gas detection system and method based on optical fiber intracavity laser | |
| Yang et al. | Photoacoustic Spectroscopy for Detection of Trace CH4 using Optimized Photoacoustic Cell |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |