CN102830259A - All-fiber current sensor - Google Patents
All-fiber current sensor Download PDFInfo
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- CN102830259A CN102830259A CN2011101644233A CN201110164423A CN102830259A CN 102830259 A CN102830259 A CN 102830259A CN 2011101644233 A CN2011101644233 A CN 2011101644233A CN 201110164423 A CN201110164423 A CN 201110164423A CN 102830259 A CN102830259 A CN 102830259A
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- 239000000835 fiber Substances 0.000 title claims abstract description 99
- 230000010287 polarization Effects 0.000 claims abstract description 55
- 230000005540 biological transmission Effects 0.000 claims abstract description 8
- 230000003287 optical effect Effects 0.000 claims description 16
- 230000008878 coupling Effects 0.000 claims description 10
- 238000010168 coupling process Methods 0.000 claims description 10
- 238000005859 coupling reaction Methods 0.000 claims description 10
- -1 quarter-wave plate Substances 0.000 claims description 2
- 239000013307 optical fiber Substances 0.000 abstract description 11
- 238000004519 manufacturing process Methods 0.000 abstract description 4
- 238000005516 engineering process Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 230000008033 biological extinction Effects 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 238000004891 communication Methods 0.000 description 1
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- 238000013461 design Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000005693 optoelectronics Effects 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
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Abstract
The invention relates to an all-fiber current sensor, which comprises a polarization beam splitter or combiner, a transmission fiber, a quarter-wave plate, a fiber reflector and a sensing fiber; the polarization beam splitter or combiner is connected with the quarter-wave plate through a transmission optical fiber; the quarter wave plate is connected with the optical fiber reflector through the sensing optical fiber. The invention provides the all-fiber current sensor which can eliminate the problems of vibration and temperature, has high maturity of devices, lower manufacturing difficulty and high precision and is suitable for realizing industrialization.
Description
Technical field
The present invention relates to a kind of fibre optic current sensor, relate in particular to a kind of all-fiber current sensor.
Background technology
Fibre optic current sensor has little, in light weight, the no magnetic saturation ferroresonance of volume problem, insulation is simple, dynamic range big, output digitizing remarkable advantage, will progressively replace traditional current sensor and becomes one of main means of power network monitoring.Wherein all-fiber current sensor is the focus of attention in this field, also is the inevitable development direction of fibre optic current sensor.Energy loss is little, simple in structure in the transmission course of all-fiber current sensor, volume is little, in light weight, through regulating the measurement sensitivity that the optical fiber number of rings can also Adjustment System.Compare with the active type fibre optic current sensor, the high-pressure side need not to provide power supply, simplifies the structure greatly, has reduced cost.Compare with little CT formula fibre optic current sensor, avoided the intrinsic problem of little CT formula from principle, like dead band, electromagnetic interference (EMI) etc.Compare with laser energy supply type fibre optic current sensor, lacked opto-electronic conversion one time, avoided the energy loss in the light power supply, the life problems of no high power laser, and fiber optic circuit is easy to check whether operate as normal of light source entirely.Thereby all-fiber current sensor has tangible application advantage, be badly in need of solving but be faced with some technical matterss, and mainly be that external environment factors such as vibration, temperature are bigger to its influence.
There is the all-fiber current sensor product in companies such as external NxtPhase; What adopt is the reflective scheme of straight wave guide; Shared sensor fibre solves vibration and temperature problem, sees " design of all-fiber current transformator detection system " of 95 pages to 112 pages of " photoelectric project " 2006 33 (5) volumes.But the core devices straight wave guide of this scheme (belongs to phase modulator; X, y both direction all can little loss lead to light; And can carry out phase modulation (PM) respectively to x, y both direction light wave) there is not a matured product in that China is domestic, seriously restricted of the practical application of this scheme in China.
The domestic reflective scheme that has unit to propose to adopt the mutually perpendicular linearly polarized light of polarization-maintaining coupler coupling two bundles is referring to the 45th page of University of Electronic Science and Technology's Master's thesis in 2006 " novel all-fiber current sensor light channel structure research ".Adopt polarization-maintaining coupler to carry out the coupling of the mutually perpendicular linearly polarized light of two bundles in this scheme optic fibre light path, require the mutually perpendicular linearly polarized light of this two bundle to get into by the slow axis of the fast axle of optical fiber and optical fiber respectively on the principle and still keep polarization angle definitely vertical after polarization-maintaining coupler is coupled.This requires polarization-maintaining coupler to guarantee the extinction ratio and the splitting ratio of fast and slow axis simultaneously, realizes this requirement and the technology of polarization-maintaining coupler is extremely difficult, only requires extinction ratio and the splitting ratio that guarantees single optical axis on the general performance to polarization-maintaining coupler.This scheme principle is reasonable, but is difficult to realize.Even along with the whole change of the production technology of technical progress polarization-maintaining coupler has realized the simultaneously accurate beam split of fast and slow axis and guaranteed extinction ratio; Polarization-maintaining coupler in this scheme optic fibre light path has the intensity losses of twice 3dB when this kind application process; Add up to the 6dB light loss; Cause the signal to noise ratio (S/N ratio) of whole current sensor lower, reduced the precision of sensing system.
Xian Inst. of Optics and Precision Mechanics, Chinese Academy of Sciences proposes a kind of in sensor fibre mid point coupling half-wave plate (ZL 200920305200.2), the Fibre Optical Sensor scheme of two-wire coiling sensor fibre.This scheme has been avoided adopting jejune device, but has all been adopted communication device under the prerequisite that has guaranteed environmental suitability, purchase unimpeded, sensor accuracy height, but the making precision of three wave plates in the scheme has been proposed higher requirement.
Summary of the invention
In order to solve the above-mentioned technical matters that exists in the background technology, the invention provides and a kind ofly eliminate vibration and temperature problem, the device degree of ripeness is high, manufacture difficulty is lower, precision is high, is fit to realize the all-fiber current sensor of industrialization.
Technical solution of the present invention is: the invention provides a kind of all-fiber current sensor, its special character is: said all-fiber current sensor comprises polarization branch or bundling device, Transmission Fibers, quarter-wave plate, fiber reflector and sensor fibre; Said polarization divides or bundling device links to each other with quarter-wave plate through Transmission Fibers; Said quarter-wave plate links to each other with fiber reflector through sensor fibre.
Above-mentioned polarization divides or bundling device comprises that polarization divides or the beam splitting end that closes bundle end and polarization branch or bundling device of bundling device; Said polarization divides or the Shu Duanyu quarter-wave plate that closes of bundling device links to each other through sensor fibre.
Above-mentioned all-fiber current sensor also comprises LASER Light Source, photodetector, first fiber coupler and Y branch multi-functional integrated optical device; Said LASER Light Source and photodetector insert Y branch multi-functional integrated optical device through first fiber coupler coupling back; Said Y branch multi-functional integrated optical device divides with polarization or the beam splitting end of bundling device links to each other.
Above-mentioned polarization divides or the beam splitting end of bundling device comprises the first beam splitting end and the second beam splitting end; Two branches of said Y branch multi-functional integrated optical device divide with polarization respectively or the first beam splitting end, the second beam splitting end of bundling device link to each other.
Above-mentioned all-fiber current sensor also comprises LASER Light Source, photodetector, first fiber coupler, second fiber coupler, the polarizer and phase-modulator; Said LASER Light Source and photodetector insert the polarizer through first fiber coupler coupling back; The said polarizer inserts the beam splitting end of polarization branch or bundling device successively through second fiber coupler and phase-modulator.
The above-mentioned polarizer is divided into two branches after through second fiber coupler; Said phase-modulator is arranged at through in one or two branch that is divided into behind second fiber coupler; Said two branches that form through the polarizer divide with polarization or the beam splitting end of bundling device links to each other.
Above-mentioned polarization divides or the beam splitting end of bundling device comprises the first beam splitting end and the second beam splitting end; Said two branches that form through the polarizer divide with polarization respectively or the first beam splitting end, the second beam splitting end of bundling device link to each other.
The present invention restraints the structural similarity of the reflective scheme of mutually perpendicular linearly polarized light with adopting polarization-maintaining coupler coupling two, but is essentially different.Need to merge the mutually perpendicular two bunch polarized lights of propagating of polarization angle in the reflective scheme of all-fiber current sensor; The polarization-maintaining coupler performance can not satisfy this requirement on technology, and polarization divides or the function polarization of bundling device closes the requirement that bundle and polarization beam splitting satisfy reflecting type full-optical fiber current sensor fully.
Advantage of the present invention is:
Among the present invention because of vibration or the Sagnac effect of rocking generation in front and back twice effect during through sensor fiber offset on the contrary; Effect is consistent when passing through sensor fiber twice because of the Faraday magnetooptical effect front and back of electric current generation, and the phase differential when two-beam meets only reflects size of current.Two beam interferometer light beams successively pass through identical light path among the present invention, thereby insensitive to temperature variation.Fibre optic current sensor of the present invention is revised parameters such as the fiber optic coils number of turns a little, can be used for direct current, ac current sensor under the various voltages.Compare with traditional electrical magnetic-type current sensor, little, in light weight, the no magnetic saturation ferroresonance of volume problem, insulation is simple, dynamic range big, the output digitizing; Compare ambient vibration with general Sagnac formula all-fiber current sensor and temperature variation is insensitive; Compare the degree of ripeness of selecting device for use with the straight wave guide reflection type optical fiber current sensor high, compares the practicality height with the polarization-maintaining coupler reflection type optical fiber current sensor, non-principle product, and also signal to noise ratio (S/N ratio) is high, and system accuracy is high; Improving Sagnac formula all-fiber current sensor with half-wave plate, to compare the element manufacturing difficulty lower; Comprehensive, the present invention is practical, is fit to realize industrialization.
Description of drawings
Fig. 1 is the structural representation of all-fiber current sensor provided by the present invention;
Fig. 2 is the structural representation of first preferred embodiment of all-fiber current sensor provided by the present invention;
Fig. 3 is the structural representation of second preferred embodiment of all-fiber current sensor provided by the present invention;
Fig. 4 is that the polarization that the present invention adopts divides or bundling device tail optical fiber synoptic diagram;
Wherein: the 1-polarization divides or bundling device; The 2-quarter-wave plate; The 3-sensor fibre; The 4-fiber reflector; The 5-LASER Light Source; The 6-photodetector; 7-first fiber coupler; 8-Y branch multi-functional integrated optical device; 9-second fiber coupler; The 10-polarizer; The 11-phase-modulator; The 12-polarization divide or bundling device close Shu Duan; The first beam splitting end of 13-polarization branch or bundling device; The second beam splitting end of 14-polarization branch or bundling device.
Embodiment
Referring to Fig. 1, the invention provides a kind of fibre optic current sensor, comprise that polarization divides or bundling device 1, quarter-wave plate 2, fiber reflector 4 and sensor fibre 3; Polarization divides or bundling device 1 links to each other with quarter-wave plate 2 through Transmission Fibers; Quarter-wave plate 2 links to each other with fiber reflector 4 through sensor fibre 3.
Referring to Fig. 2; Fig. 3 and Fig. 4; Fibre optic current sensor provided by the present invention also comprises LASER Light Source 5, photodetector 6, first fiber coupler 7, Y branch multi-functional integrated optical device 8; Certainly, this Y branch multi-functional integrated optical device 8 also can adopt several devices of separation to form, and comes together to realize the function of Y branch multi-functional integrated optical device 8 such as the polarizer 10, second fiber coupler 9 and phase-modulator 11.
LASER Light Source 5 and photodetector 6 link to each other with Y branch multi-functional integrated optical device 8 through first fiber coupler, 7 backs; Two branches of Y waveguide multi-functional integrated optical device 8 link to each other with first beam splitting end 13 of polarization branch or bundling device and the second beam splitting end 14 of polarization branch or bundling device respectively.
Principle of work of the present invention is: core of the present invention---the optical fiber sensing structure part, realize the coupling of intersection aligning and the decomposition of two mutually perpendicular linearly polarized lights with polarization branch or bundling device 1.Two bunch polarized lights divide through polarization or coupling is aimed at by intersection in bundling device 1 back; Linearly polarized light is converted into dextrorotation (left-handed) circularly polarized light during again through quarter-wave plate 2; Is left-handed (dextrorotation) circularly polarized light through sensor fibre 3 backs by fiber reflector 4 conversion rotation directions; With the opposite sensor fibre 3 that oppositely passes through once more, by the switched back polarized light, but this moment, polarization state was converted into original vertical polarization attitude when passing through quarter-wave plate 2 again.
Polarization divides or the effect of bundling device 1 can be divided into polarization by the difference of the direction of propagation of light wave and closes bundle and polarization beam splitting.Polarization closes bundle and is exactly two bundles are divided by polarization respectively or the first beam splitting end 13 of bundling device and polarization divides or the second beam splitting end 14 of bundling device gets into that polarizations divide or the linearly polarized light of bundling device keeps that polarization angle is vertical coupled to be divided or the bundle end 12 that closes of bundling device merges and propagates out at polarization together; Polarization beam splitting be with divide from polarization or bundling device close a branch of light wave that bundle end 12 gets into by polarization mode be decomposed into two bunch polarized lights shake respectively branchs/bundling device the first beam splitting end 13 and polarization divides or the second beam splitting end 14 of bundling device is exported.
Claims (7)
1. all-fiber current sensor, it is characterized in that: said all-fiber current sensor comprises polarization branch or bundling device, Transmission Fibers, quarter-wave plate, fiber reflector and sensor fibre; Said polarization divides or bundling device links to each other with quarter-wave plate through Transmission Fibers; Said quarter-wave plate links to each other with fiber reflector through sensor fibre.
2. all-fiber current sensor according to claim 1 is characterized in that: said polarization divides or bundling device comprises that polarization divides or the beam splitting end that closes bundle end and polarization branch or bundling device of bundling device; Said polarization divides or the Shu Duanyu quarter-wave plate that closes of bundling device links to each other through sensor fibre.
3. all-fiber current sensor according to claim 1 and 2 is characterized in that: said all-fiber current sensor also comprises LASER Light Source, photodetector, first fiber coupler and Y branch multi-functional integrated optical device; Said LASER Light Source and photodetector insert Y branch multi-functional integrated optical device through first fiber coupler coupling back; Said Y branch multi-functional integrated optical device divides with polarization or the beam splitting end of bundling device links to each other.
4. all-fiber current sensor according to claim 3 is characterized in that: said polarization divides or the beam splitting end of bundling device comprises the first beam splitting end and the second beam splitting end; Two branches of said Y branch multi-functional integrated optical device divide with polarization respectively or the first beam splitting end, the second beam splitting end of bundling device link to each other.
5. all-fiber current sensor according to claim 1 and 2 is characterized in that: said all-fiber current sensor also comprises LASER Light Source, photodetector, first fiber coupler, second fiber coupler, the polarizer and phase-modulator; Said LASER Light Source and photodetector insert the polarizer through first fiber coupler coupling back; The said polarizer inserts the beam splitting end of polarization branch or bundling device successively through second fiber coupler and phase-modulator.
6. all-fiber current sensor according to claim 5 is characterized in that: the said polarizer is divided into two branches after through second fiber coupler; Said phase-modulator is arranged at through in one or two branch that is divided into behind second fiber coupler; Said two branches that form through the polarizer divide with polarization or the beam splitting end of bundling device links to each other.
7. all-fiber current sensor according to claim 6 is characterized in that: said polarization divides or the beam splitting end of bundling device comprises the first beam splitting end and the second beam splitting end; Said two branches that form through the polarizer divide with polarization respectively or the first beam splitting end, the second beam splitting end of bundling device link to each other.
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| Application Number | Priority Date | Filing Date | Title |
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| CN2011101644233A CN102830259A (en) | 2011-06-17 | 2011-06-17 | All-fiber current sensor |
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| Application Number | Priority Date | Filing Date | Title |
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| CN2011101644233A CN102830259A (en) | 2011-06-17 | 2011-06-17 | All-fiber current sensor |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103063898A (en) * | 2012-12-20 | 2013-04-24 | 中国科学院西安光学精密机械研究所 | Sensing optical fiber ring and all-fiber current transformer |
| CN103257266A (en) * | 2013-04-21 | 2013-08-21 | 国家电网公司 | Portable all-insulation optical-fiber current detector |
| WO2015149473A1 (en) * | 2014-04-03 | 2015-10-08 | 易能乾元（北京）电力科技有限公司 | Optical current sensor |
| CN107132862A (en) * | 2017-05-18 | 2017-09-05 | 国网辽宁省电力有限公司盘锦供电公司 | All-fiber current transformator secondary acquisition device thermostatic control system |
| CN111044771B (en) * | 2019-12-31 | 2021-01-05 | 华中科技大学 | Non-closed optical fiber loop current sensing device and current measuring method |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05188090A (en) * | 1992-01-13 | 1993-07-27 | Toyo Commun Equip Co Ltd | Optical current sensor |
| JPH0618567A (en) * | 1992-04-07 | 1994-01-25 | Nissin Electric Co Ltd | Optical-fiber current sensor |
| CN101334427A (en) * | 2008-07-16 | 2008-12-31 | 上海大学 | Reflecting type full-optical fiber current sensor |
| CN201429646Y (en) * | 2009-06-26 | 2010-03-24 | 中国科学院西安光学精密机械研究所 | Optical fiber current sensor |
| CN101957399A (en) * | 2010-09-21 | 2011-01-26 | 中国电力科学研究院 | Digital closed loop type optical fiber current sensor |
| CN202133701U (en) * | 2011-06-17 | 2012-02-01 | 中国科学院西安光学精密机械研究所 | All-fiber current sensor |
-
2011
- 2011-06-17 CN CN2011101644233A patent/CN102830259A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05188090A (en) * | 1992-01-13 | 1993-07-27 | Toyo Commun Equip Co Ltd | Optical current sensor |
| JPH0618567A (en) * | 1992-04-07 | 1994-01-25 | Nissin Electric Co Ltd | Optical-fiber current sensor |
| CN101334427A (en) * | 2008-07-16 | 2008-12-31 | 上海大学 | Reflecting type full-optical fiber current sensor |
| CN201429646Y (en) * | 2009-06-26 | 2010-03-24 | 中国科学院西安光学精密机械研究所 | Optical fiber current sensor |
| CN101957399A (en) * | 2010-09-21 | 2011-01-26 | 中国电力科学研究院 | Digital closed loop type optical fiber current sensor |
| CN202133701U (en) * | 2011-06-17 | 2012-02-01 | 中国科学院西安光学精密机械研究所 | All-fiber current sensor |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103063898A (en) * | 2012-12-20 | 2013-04-24 | 中国科学院西安光学精密机械研究所 | Sensing optical fiber ring and all-fiber current transformer |
| CN103063898B (en) * | 2012-12-20 | 2015-11-18 | 中国科学院西安光学精密机械研究所 | Sensing optical fiber ring and all-fiber current transformer |
| CN103257266A (en) * | 2013-04-21 | 2013-08-21 | 国家电网公司 | Portable all-insulation optical-fiber current detector |
| WO2015149473A1 (en) * | 2014-04-03 | 2015-10-08 | 易能乾元（北京）电力科技有限公司 | Optical current sensor |
| CN107132862A (en) * | 2017-05-18 | 2017-09-05 | 国网辽宁省电力有限公司盘锦供电公司 | All-fiber current transformator secondary acquisition device thermostatic control system |
| CN111044771B (en) * | 2019-12-31 | 2021-01-05 | 华中科技大学 | Non-closed optical fiber loop current sensing device and current measuring method |
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