CN1971225A - High-capacity optical fiber grating temperature-measuring system - Google Patents
High-capacity optical fiber grating temperature-measuring system Download PDFInfo
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- CN1971225A CN1971225A CN200510016310.3A CN200510016310A CN1971225A CN 1971225 A CN1971225 A CN 1971225A CN 200510016310 A CN200510016310 A CN 200510016310A CN 1971225 A CN1971225 A CN 1971225A
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Abstract
A high capacity fibre-optical grating thermometry system is disclosed, specifically a fibre-optical grating sensor which is used in high-voltage electrical power system to monitor temperature and thermometry device with this sensor. It includes fibre-optical grating sensor, a photocoupler or ring laser is connected with wide-band light source and standard fibre-optical grating via optical fibre; the standard fibre-optical grating is connected with common port of the 1*n optical switch, branching ports of the optical switch are connected with every measuring channel, a group of sensors are mounted on every measuring channel, the third branching port of the photocoupler or ring laser is connected with demodulator via optical fibre; The output of the demodulator is connected with signal processing unit; the signal processing unit has output connected with special computer which is used to control, collect, display and store. The wide-band light source is C band wide-band light source that the 3dB bandwidth is 40nm and control wave length is 1550nm; or C+L band wide-band light source that the 3dB bandwidth is 80nm and control wave length is 1570nm.
Description
Technical field
The invention belongs to technical field of optical fiber sensing, in particular for the fiber-optic grating sensor of high-voltage electric power system monitor temperature and have the temperature measuring equipment of this sensor.
Background technology
Be in the electric system of high-pressure work state, as becoming, distribution substation or power supply, electricity generation system etc., be subjected to influence of various factors, swing such as the cable of equipment, the power frequency vibration of electrical equipment, equipment is worked under the environmental baseline of humidity, and under construction or maintenance defective workmanship and the air oxidation effect, in the high pressure major loop of described equipment, it is big that the contact resistance of device junction can become gradually, thereby joint surface generates heat thereupon, contact resistance is progressively increased, the vicious cycle that causes connector temperature to raise, as can not in time monitoring the temperature variation of device junction, operational outfit fire or ground short circuit accident just can hardly be avoided.
In known monitoring technology, traditional electrical sensor is subject to ambient humidity and electromagnetic interference (EMI) in electric system, also because of it is an active device, can't use under inflammable and explosive rugged surroundings.Therefore, industry is constantly invented the problem that new measuring technique solves high-voltage electric power system temperature survey difficulty, as Infrared survey, wireless measurement, fiber optic temperature detection system and optical fiber, optical grating temperature test system.Infrared survey costs an arm and a leg and can only spot measurement.Optical fiber temperature-measurement belongs to intensity monitor, and be subject to light source and rise and fall, factor affecting measuring accuracy such as device aging and fibre-optical bending, and also equipment is very expensive, and comparatively advanced is fiber-optic grating sensor.
Fiber-optic grating sensor belongs to Wavelength-encoding, not influenced by light source fluctuating, device aging, fibre-optical bending etc., therefore has extreme high reliability and precision.
Known fiber grating detection technique as:
Chinese patent CN03229855.2 discloses a kind of thermal tuning fiber sensor demodulator, and it is that fiber grating is fixed on the miniature electric resistance heater for its characteristics, and the two ends of this miniature electric resistance heater are linked to each other with a modulation power source by pair of lead wires and constitute.
Chinese patent CN03229854.4 strain tunable fiber grating sensing detuner, its characteristics are that its formation is: the fiber segment that contains fiber grating, the two ends of this fiber segment are fixed on the casing by two fibre holders respectively, and one can drive fiber segment makes the Vib. of transverse vibration and also be fixed on this casing.
Chinese patent application CN200410020745.0 discloses a kind of optic fiber grating wavelength demodulation method.It is characterized by the employing wideband light source, use the fiber grating that is cascaded in pairs, a conduct is with reference to grating, another is as measuring grating, the foveal reflex wavelength difference of two fiber gratings is less than half of reflection bandwidth, when the foveal reflex wavelength difference of two fiber gratings changes, back light power can change, by this a pair of fiber grating being returned the measurement of power, can obtain measuring grating foveal reflex wavelength relative reference fiber grating foveal reflex wavelength change, thereby the realization Wavelength demodulation, the right foveal reflex wavelength difference of fiber grating is made as single fiber grating reflection bandwidth 1/4, can obtain better linearity.
Chinese patent CN200420028699.4 discloses a kind of multi-channel optical fibre raster sensor, this device comprises by wideband light source, three end optical circulators, at least two FBG sensors, fiber coupler, the multi-channel optical fibre raster sensor that wavelengt demodulator and photodetector are formed, it is characterized in that, wavelengt demodulator adopts the dense wavelength division demodulation multiplexer, its input end links to each other with an output terminal of fiber coupler, at least be provided with two wavelength channels in the dense wavelength division demodulation multiplexer, wavelength channel number and FBG sensor number are complementary, the output terminal of dense wavelength division demodulation multiplexer connects at least two photodetectors, and the number and the FBG sensor number of the photodetector that output terminal connects are complementary.
This kind tunable technology cost is higher, the systematic comparison complexity.
Also have american documentation literature to disclose US5,729,347 " based on linear edges band filter methods "; US5,882,049 " based on the relevant coupling process of wavelength "; US6,335,53 " utilizing the method for chirp grating ".Known fiber grating demodulation technology ubiquity tuning range is little, and the problem that resolution is low still can not satisfy the more needs of high capacity multiple spot detection.
Summary of the invention
Problem to be solved by this invention is to overcome the above-mentioned defective that aforementioned techniques exists, and a kind of optical fiber grating temperature-measuring system is provided.
Its technical matters of optical fiber temperature-measurement device solves of the present invention takes following technical scheme to realize, according to a kind of high-capacity optical fiber grating temperature-measuring system provided by the invention, comprises fiber-optic grating sensor, wherein,
One photo-coupler or optical circulator, its first fen road port is connected with wideband light source by optical fiber; Road port connected the standard fiber grating by optical fiber in second minute;
The standard fiber grating is connected with the common port of the photoswitch of one 1 * n, and the branch road port of this photoswitch is connected each and measured passage, and each is measured passage one sensor groups is set,
The 3rd fen road port of described photo-coupler or optical circulator links to each other with detuner by optical fiber; The output terminal of this detuner is connected with signal processing unit; This signal processing unit has and is responsible for control, gathers, shows the output terminal that is connected with the special purpose computer unit that stores.
High-capacity optical fiber grating temperature-measuring system of the present invention solves its technical matters and can also take following technical scheme further to realize:
Aforesaid high-capacity optical fiber grating temperature-measuring system, wherein, described sensor groups is formed by laying 1-n the fiber-optic grating sensor with different centre wavelengths that is in series by the preset wavelength coding; Described sensor groups can be the 1-n group.
Aforesaid high-capacity optical fiber grating temperature-measuring system, wherein, described wideband light source is that three dB bandwidth is the C-band wideband light source of 1550nm for 40nm centre wavelength; Or three dB bandwidth is the C+L wave band wideband light source of 1570nm for 80nm centre wavelength.
Aforesaid high-capacity optical fiber grating temperature-measuring system, wherein, described demodulating equipment has the adjustable filter chip by electric field controls.
Aforesaid high-capacity optical fiber grating temperature-measuring system, wherein, described standard fiber grating with temperature compensation after, the encapsulation bragg grating; Described fiber-optic grating sensor has optical fiber insulator.
Aforesaid high-capacity optical fiber grating temperature-measuring system, wherein, described optical fiber insulator is made of the optical fiber insulator unit of mutual serial connection, and this optical fiber insulator unit has the slightly disc portion of tapering, stretches along the top corner part on this disc portion tapering surface and establishes the stem that installs optical fiber.
Aforesaid high-capacity optical fiber grating temperature-measuring system, wherein, the optical fiber insulator one end device Temperature probe of described fiber-optic grating sensor, the other end is connected with optical fiber by fiber connector, installs optical cable on the optical fiber insulator.Described optical fiber insulator unit is that one compression moulding of hydrophobic nature elastomeric material or described optical fiber insulator unit have hydrophobic coat.
Aforesaid high-capacity optical fiber grating temperature-measuring system, wherein, described Temperature probe body has the streamlined groove of optical fibre, and an end of this groove leaves the outlet notch that optical fiber merging is altogether drawn; Described groove is a U type groove; The Temperature probe body has a survey object plane that contacts with measured object; Optical fiber streams the line style groove sets two leading-out ends and merges a place, draws by the outlet notch, passes optical fiber insulator on the optical fiber, and the end of optical fiber is connected with fiber connector.
The present invention compared with prior art has significant advantage and beneficial effect.By above technical scheme as can be known, the present invention has following advantage at least under the structural arrangements of excellence:
The optical fiber insulator of this case configuration has well solved the creepage problem of high pressure, has improved the use power-frequency voltage greatly; Described demodulating equipment setting has improved demodulation scope and demodulation speed by electric field controls adjustable filter chip, has solved magnetic hysteresis and unstable temperature problem simultaneously, has therefore improved the measurement reliability.1 * n photoswitch is disposed in this case, can constitute the safety detecting system of multiple spot multi-channel and high capacity.Client's different requirements are satisfied in sound, light early warning and warning device configuration that this case is convenient and known.The configuration of this case standard fiber grating makes pick-up unit have self-correcting function.Wherein the fiber-optic grating sensor setting meets the packaging structure of electrical equipment joint geometry, is that pick-up unit is not risen and fallen by light source, device aging, and influences such as fibre-optical bending can effectively improve accuracy of detection; The present invention utilizes the different centre wavelengths of fiber grating, disposes complete control system, can a plurality of transformer stations form the concentrated monitoring of network, and each temperature variation is all known its particular location and place and precise time, is convenient to have the purpose maintenance.The present invention compared with prior art has significant technical progress, can be rated as have novelty, the good technology of creativeness, practicality.
The specific embodiment of the present invention is provided in detail by following examples and accompanying drawing thereof.
Description of drawings
Fig. 1 is a structured flowchart of the present invention;
Fig. 2 is fiber-optic grating sensor one an example structure synoptic diagram among the present invention;
Fig. 2 a is the another example structure synoptic diagram of fiber-optic grating sensor among the present invention;
Fig. 3 is an optical fiber insulator cellular construction synoptic diagram in the fiber-optic grating sensor of the present invention;
Fig. 4 is a Bragg fiber grating basic structure synoptic diagram among the present invention;
Fig. 5 is a Bragg fiber grating transmission spectrum among the present invention;
Fig. 6 is that the present invention combines formation detection system sketch with the special purpose computer unit.
Embodiment
Below in conjunction with accompanying drawing and preferred embodiment, to according to embodiment provided by the invention, structure, feature and effect thereof, describe in detail as after.
A kind of high capacity high-capacity optical fiber grating temperature-measuring system shown in Fig. 1-6, wherein,
One photo-coupler or optical circulator 3, its first fen road port is connected with wideband light source 1 by optical fiber 10; Its second fen road port c connects standard fiber grating 5 by optical fiber;
Described sensor groups can be the 1-n group; Can realize the technical purpose of multiple spot multi-channel detection thus.The 3rd fen road port b of described photo-coupler or optical circulator 3 links to each other with detuner 6 by optical fiber 10; The output terminal of detuner is connected with signal processing unit 8; This signal processing unit 8 has and is responsible for control, gathers, shows the output terminal that is connected with the special purpose computer unit 9 that stores;
This device connects the special purpose computer unit, and computer unit and known acoustic-optic alarm configuration can realize early warning and alarming.
According to the quantity of required metering contact what, described wideband light source 1 is that three dB bandwidth is the C-band wideband light source of 1550nm for 40nm centre wavelength; Or three dB bandwidth is the C+L wave band wideband light source of 1570nm for 80nm centre wavelength;
Described standard fiber grating 5 is with the bragg grating after the temperature compensation;
Described standard fiber grating 5 is bragg gratings of encapsulation; Described encapsulating structure includes but not limited to disclosed our company patent 03202546.7 packaging system, makes the error of measuring accuracy through the standard fiber grating 5 after this encapsulation in the scope that industry standard allows with the ambient temperature variation.Described fiber-optic grating sensor 4 has optical fiber insulator 41;
Described optical fiber insulator 41 is made of several the horn-like optical fiber insulator unit 410 that are connected in series mutually according to measured object high pressure ratings match, has the slightly disc portion 4101 of tapering, the tapering surface of the disc portion of optical fiber insulator unit can effectively avoid dust to adhere to, stretch along the top corner part on this disc portion tapering surface and to establish the stem 4102 that installs optical fiber, the circumferential edges of disc portion has convex edge 4103, to improve the mar proof and the insulating capacity of optical fiber insulator.
Described fiber-optic grating sensor 4 comprises Temperature probe 42, wherein, an optical fiber insulator 41 1 end device Temperature probes 42, the other end is connected with optical fiber by fiber connector, device optical cable 43,44 on the optical fiber insulator 41;
Described fiber-optic grating sensor can be, comprises Temperature probe, and wherein, Temperature probe body 421 has the streamlined groove 422 of optical fibre, and an end of this groove leaves altogether that optical fiber merges the outlet notch 423 of drawing; Described groove is a U type groove; The Temperature probe body has a survey object plane 424 that contacts with measured object; Optical fiber streams the line style groove sets two leading-out ends and merges a place, draws by outlet notch 423, passes optical fiber insulator 41 on the optical fiber, and the end of optical fiber is connected with fiber connector; Described optical fiber insulator unit 410 has hydrophobic coat for one compression moulding of hydrophobic nature elastomeric material or described optical fiber insulator unit 410.
The aforementioned optical fiber insulator of described fiber-optic grating sensor 4 configurations can effectively improve the strong and electric durability energy of hydrophobic nature, pick-up unit with this fiber-optic grating sensor is under filthy naturally condition and greasy weather moisture conditions, the level of anti-power-frequency voltage that can more obvious raising optical fiber, switching overvoltage, lightning surge can effectively solve the grating fibers temp measuring system in inclement weather and the operating safety problem of environment.The described demodulating equipment setting of this case has improved demodulation scope and demodulation speed by the adjustable filter sheet (MEMS) of electric field controls, has solved magnetic hysteresis and unstable temperature problem simultaneously, has therefore improved the measurement reliability.Because of this adjustable filter chip by electric field controls, under electric field action, move, thereby it does not have the hysteresis of piezoelectric ceramics, reaction velocity is fast, the degree of accuracy height.
The know-why fiber-optic grating sensor is mainly used the Bragg fiber grating, Bragg fiber grating basic structure as shown in Figure 4, the striped in the fibre core is represented the cyclical variation of refractive index.According to incident light, reflected light, transmitted light and associated laws of conservation of energy and momentum, obtain the variation of the reflection wavelength of Bragg, the relation of the variation of reflection wavelength and optical fiber axial strain, can constitute a lot of physical quantitys (as, pressure, deformation, displacement, electric current, voltage, vibration, speed, acceleration, flow or the like) funtcional relationship, Bragg fiber grating has very premium properties, the reflectivity height, and narrow bandwidth can be less than 0.2nm.
When the Bragg fiber grating that this refractive index cycle changes satisfies phase-matching condition, incident light will be reflected, peak reflectance wavelength:
λ
B＝2n
effΛ (1)
In the formula: λ B is Bragg wavelength (being the grating reflection wavelength); Λ is the grating cycle; n
EffEffective refractive index for fiber optic materials.Fig. 2 is an actual Bragg fiber grating reflectance spectrum and transmission spectrum.
Formula n
Eff, among the Λ (1), be the function of temperature T and axial strain ε, so the long relative variation of cloth loudspeaker lattice wave can be write as:
Δλ/λB＝(α+ξ)ΔT+(1-Pe)ε (2)
Wherein α, ξ are respectively the thermal expansivity and the thermo-optical coeffecients of optical fiber, and it is worth α=0.55 * 10-6, ξ=8.3 * 10-6, and promptly temperature control approximately is 0.0136nm/ ℃, (λ is 1550nm); Pe is effective strain optical coefficient, is approximately 0.22, and promptly strain sensitivity is 0.001209nm/ μ ε.Therefore, utilize the above-mentioned relation formula to measure the wavelength change amount and just can measure temperature and strain.Using optical fibre grating can produce the sensing head of different purposes, and the variation of measuring grating wavelength just can calculate the variation of measured physical quantity, so (2) formula is the fundamental equation of grating sensing.
The above only is preferred embodiment of the present invention, be not that the present invention is done any pro forma restriction, every foundation technical spirit of the present invention all still belongs in the scope of technical solution of the present invention any simple modification, equivalent variations and modification that above embodiment did.
Claims (8)
1, a kind of high-capacity optical fiber grating temperature-measuring system comprises fiber-optic grating sensor, it is characterized in that,
One photo-coupler or optical circulator (3), its first minute road port (a) be connected with wideband light source (1) by optical fiber (10); Its second minute road port (c) connect standard fiber grating (5) by optical fiber;
Standard fiber grating (5) is connected with the common port of the photoswitch (2) of one 1 * n, and the branch road port of this photoswitch (2) is connected each and measured passage, and each is measured passage one sensor groups (An) is set,
Described photo-coupler or optical circulator (3) the 3rd minute road port (b) link to each other with detuner (6) by optical fiber (10); The output terminal of this detuner is connected with signal processing unit (8); This signal processing unit has and is responsible for control, gathers, shows and special purpose computer unit (90 output terminals that are connected that store.
2. high-capacity optical fiber grating temperature-measuring system according to claim 1 is characterized in that, described sensor groups (An) is formed by laying 1-n the fiber-optic grating sensor with different centre wavelengths (4) that is in series by the preset wavelength coding; Described sensor groups can be the 1-n group.
3. high-capacity optical fiber grating temperature-measuring system according to claim 1 and 2 is characterized in that, described wideband light source (1) is that three dB bandwidth is the C-band wideband light source of 1550nm for 40nm centre wavelength; Or three dB bandwidth is the C+L wave band wideband light source of 1570nm for 80nm centre wavelength.
4. high-capacity optical fiber grating temperature-measuring system according to claim 3 is characterized in that, described demodulating equipment has the adjustable filter chip by electric field controls.
5. high-capacity optical fiber grating temperature-measuring system according to claim 4 is characterized in that, described standard fiber grating (5) with after the temperature compensation, the encapsulation bragg grating; Described fiber-optic grating sensor (4) has optical fiber insulator (41).
6. high-capacity optical fiber grating temperature-measuring system according to claim 5, it is characterized in that, described optical fiber insulator (41) is made of the optical fiber insulator unit (410) of mutual serial connection, this optical fiber insulator unit has the slightly disc portion (4101) of tapering, stretches along the top corner part on this disc portion tapering surface and establishes the stem (4102) that installs optical fiber;
7. according to the described high-capacity optical fiber grating temperature-measuring system of claim 6, optical fiber insulator (41) the one end device Temperature probes (42) of described fiber-optic grating sensor, the other end is connected with optical fiber by fiber connector, installs optical cable (43,44) on the optical fiber insulator; Described optical fiber insulator unit (410) has hydrophobic coat for one compression moulding of hydrophobic nature elastomeric material or described optical fiber insulator unit (410).
8. high-capacity optical fiber grating temperature-measuring system according to claim 7, it is characterized in that, described Temperature probe body (421) has the streamlined groove (422) of optical fibre, and an end of this groove leaves the outlet notch (423) that optical fiber merging is altogether drawn; Described groove is a U type groove; The Temperature probe body has a survey object plane (424) that contacts with measured object; Optical fiber streams the line style groove sets two leading-out ends and merges a place, draws by the outlet notch, passes optical fiber insulator (41) on the optical fiber, and the end of optical fiber is connected with fiber connector.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101881631A (en) * | 2010-06-02 | 2010-11-10 | 南京航空航天大学 | FBG (Fiber Bragg Grating) sensor network monitoring system based on photoswitch |
| CN103454014A (en) * | 2012-05-31 | 2013-12-18 | 基德科技公司 | Optical fiber sensing system |
| CN107271074A (en) * | 2017-06-07 | 2017-10-20 | 北京昕天卫光电科技有限公司 | A kind of High-Voltage Electrical Appliances optical fiber grating temperature-measuring system |
| CN108871221A (en) * | 2018-07-13 | 2018-11-23 | 程克玲 | A kind of bridge monitoring device |
| CN108931262A (en) * | 2018-06-01 | 2018-12-04 | 北京华工信息技术有限公司 | It is a kind of for monitoring the optical fiber sensing system of structural safety |
| CN110518442A (en) * | 2019-07-10 | 2019-11-29 | 杭州电子科技大学 | Dual wavelength lead selenide quantum dot optical fiber laser with super continuous spectrum |
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2005
- 2005-11-21 CN CN200510016310.3A patent/CN1971225A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101881631A (en) * | 2010-06-02 | 2010-11-10 | 南京航空航天大学 | FBG (Fiber Bragg Grating) sensor network monitoring system based on photoswitch |
| CN103454014A (en) * | 2012-05-31 | 2013-12-18 | 基德科技公司 | Optical fiber sensing system |
| CN107271074A (en) * | 2017-06-07 | 2017-10-20 | 北京昕天卫光电科技有限公司 | A kind of High-Voltage Electrical Appliances optical fiber grating temperature-measuring system |
| CN108931262A (en) * | 2018-06-01 | 2018-12-04 | 北京华工信息技术有限公司 | It is a kind of for monitoring the optical fiber sensing system of structural safety |
| CN108871221A (en) * | 2018-07-13 | 2018-11-23 | 程克玲 | A kind of bridge monitoring device |
| CN108871221B (en) * | 2018-07-13 | 2020-08-04 | 四川衡兴泰工程技术咨询服务有限公司 | Bridge monitoring device |
| CN110518442A (en) * | 2019-07-10 | 2019-11-29 | 杭州电子科技大学 | Dual wavelength lead selenide quantum dot optical fiber laser with super continuous spectrum |
| CN110518442B (en) * | 2019-07-10 | 2020-09-01 | 杭州电子科技大学 | Dual-wavelength lead selenide quantum dot super-continuum spectrum optical fiber laser |
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