CN115184661A - All-fiber current transformer based on fiber ring cavity and current measuring method - Google Patents
All-fiber current transformer based on fiber ring cavity and current measuring method Download PDFInfo
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
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Abstract
The invention discloses an all-fiber current transformer based on an optical fiber annular cavity and a current measuring method. The all-fiber current transformer improves the sensitivity by utilizing multiple circulations in the fiber annular cavity, can effectively reduce the number of sensing fiber turns wound on a lead, is favorable for realizing high precision and miniaturization of the all-fiber current transformer, adopts a narrow-band light source instead of a wide-band light source, and can inhibit the transformation ratio error of the all-fiber current transformer caused by the central wavelength drift of the light source.
Description
Technical Field
The invention belongs to the technical field of optical fiber sensing, and particularly relates to an all-fiber current transformer based on an optical fiber ring cavity and a current measuring method.
Background
The all-fiber current transformer is a sensor for measuring current in a power grid, and plays a crucial role in the power industry. Compared with the traditional electromagnetic induction type current transformer, the all-fiber current sensor based on the Faraday magneto-optical effect and the ampere loop law has obvious advantages in the aspects of volume, weight, dynamic measurement range, electromagnetic interference resistance, safety and the like.
According to the signal detection mode, the current all-fiber current transformer can be divided into two types: polarization type all-fiber current transformers and interference type all-fiber current transformers. The polarization type all-fiber current transformer obtains current information to be measured by directly detecting the rotation angle of the polarization plane of linearly polarized light. The interference type all-fiber current transformer obtains current information to be detected by detecting phase difference converted by rotation of a polarization plane, wherein the interference type all-fiber current transformer can be subdivided into a Sagnac gyro type and a reflection type according to different light path structures.
No matter the polarization type all-fiber current transformer or the interference type all-fiber current transformer, the sensitivity needs to be improved by increasing the number of turns of the sensing fiber wound on the lead, which is not beneficial to realizing high precision and miniaturization of the all-fiber current transformer. In addition, the polarization type all-fiber current transformer or the interference type all-fiber current transformer adopts a broadband light source, and because a Verdet constant has wavelength dependence, the central wavelength drift of the light source can cause the all-fiber current transformer to generate a transformation ratio error.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides an all-fiber current transformer based on an optical fiber ring cavity and a current measuring method. The technical problem to be solved by the invention is realized by the following technical scheme:
a first aspect of the embodiments of the present invention provides an all-fiber current transformer based on an optical fiber ring cavity, including: the optical fiber circulator comprises a light source, a Y-branch phase modulation device, a first optical fiber circulator, a second optical fiber circulator, an optical fiber ring cavity (9), a first photoelectric detector, a second photoelectric detector and a digital signal processing unit; the line width of the light source is less than 200kHz;
the Y-branch phase modulation device is used for dividing source light emitted by the receiving light source into two beams of light and respectively carrying out phase modulation on the two beams of light;
the first optical fiber circulator is positioned on one light path of the Y-branch phase modulation device and is connected with the Y-branch phase modulation device, the optical fiber ring cavity and the first photoelectric detector;
the second optical fiber circulator is positioned on the other light path of the Y-branch phase modulation device and is connected with the Y-branch phase modulation device, the optical fiber ring cavity and the second photoelectric detector;
the optical fiber ring cavity is of a symmetrical structure and forms an annular light path, and is used for coupling two beams of light passing through the first optical fiber circulator and the second optical fiber circulator to form clockwise light waves and anticlockwise light waves which are transmitted in clockwise and anticlockwise directions, converting the clockwise light waves and the anticlockwise light waves into linearly polarized light after converting the linearly polarized light into circularly polarized light, and performing multiple circulations and output of the clockwise light waves and the anticlockwise light waves in the optical fiber ring cavity;
the first photoelectric detector is connected with the digital signal processing unit and is used for receiving the clockwise light wave output by the optical fiber annular cavity;
the second photoelectric detector is connected with the digital signal processing unit and used for receiving the anticlockwise light wave output by the optical fiber annular cavity;
the digital signal processing unit is connected with the light source, and is used for adjusting the frequency of light output by the light source (1) and detecting the difference between the resonant frequencies in the clockwise direction and the counterclockwise direction of the optical fiber ring cavity according to the output signals of the first photoelectric detector and the second photoelectric detector so as to acquire the information of the current to be detected.
In one embodiment of the present invention, the Y-branch phase modulation apparatus includes: the device comprises an optical splitter, a first electro-optic phase modulator and a second electro-optic phase modulator;
the optical splitter is used for splitting source light emitted by a receiving light source into two beams of light, and two output ports are respectively connected with the first electro-optical phase modulator and the second electro-optical phase modulator;
the first electro-optic phase modulator and the second electro-optic phase modulator are used for respectively receiving the two beams of light emitted by the optical splitter and respectively carrying out phase modulation on the two beams of light;
the first electro-optical phase modulator is connected with the first optical fiber circulator;
and the second electro-optic phase modulator is connected with the second optical fiber circulator.
In one embodiment of the present invention, the optical fiber ring cavity includes: the optical fiber polarization controller comprises a 2X 2 optical fiber coupler, a first polarization control unit, a first lambda/4 wave plate, a sensing optical fiber, a second polarization control unit and a second lambda/4 wave plate which are connected through optical fibers to form an annular optical path;
the 2 x 2 optical fiber coupler is connected with the first optical fiber circulator, the second optical fiber circulator and the first polarization control unit; the 2 x 2 optical fiber coupler is used for coupling two beams of light passing through the first optical fiber circulator and the second optical fiber circulator to form the clockwise light wave and the counterclockwise light wave which are transmitted in the clockwise direction and the counterclockwise direction;
the first polarization control unit is connected with the first lambda/4 wave plate;
the first lambda/4 wave plate is connected with the sensing optical fiber;
the sensing optical fiber is connected with the second lambda/4 wave plate;
the second lambda/4 wave plate is connected with the second polarization control unit and the 2 x 2 optical fiber coupler;
the first polarization control unit, the first lambda/4 wave plate, the second lambda/4 wave plate and the second polarization control unit are used for converting the clockwise light wave and the anticlockwise light wave into linearly polarized light after the linearly polarized light is converted into circularly polarized light;
and the sensing optical fiber is wound on the measured current conducting wire.
In one embodiment of the present invention, the digital signal processing unit includes: the device comprises a first waveform generator, a second waveform generator, a first synchronous demodulation module and a second synchronous demodulation module;
the first synchronous demodulation module is connected with the first photoelectric detector and the first waveform generator;
the first waveform generator is connected with the second phase modulator;
the second synchronous demodulation module is connected with the second photoelectric detector and the second waveform generator;
the second waveform generator is connected with the first phase modulator;
the light source is connected with the first synchronous demodulation module or the second synchronous demodulation module.
In one embodiment of the present invention, when the first λ/4 plate is welded to the first polarization control unit, the polarization axis is rotated by 45 ° and welded; when the second lambda/4 wave plate is welded with the second polarization control unit, the polarization axis rotates 45 degrees and is welded.
A second aspect of the embodiments of the present invention provides a current measurement method for an all-fiber current transformer based on an optical fiber ring cavity, where the method is applied to the current transformer described in the first aspect of the embodiments of the present invention, and includes the following steps:
step S1: generating a source light wave by a light source and transmitting the source light wave into a Y-branch phase modulation device; the line width of the light source is less than 200kHz;
step S2: the Y-branch phase modulation device divides the source light wave into two beams of light, and the ratio of the light power of the two beams of light is 1;
and step S3: the Y-branch phase modulation device is used for carrying out phase modulation of different frequencies on the two light waves;
and step S4: two beams of light after phase modulation enter the optical fiber annular cavity through the first optical fiber circulator and the second optical fiber circulator and are coupled to form clockwise light waves and anticlockwise light waves which are transmitted in the clockwise direction and the anticlockwise direction;
step S5: in the optical fiber annular cavity, the clockwise light wave and the anticlockwise light wave are respectively converted into left-handed circularly polarized light and right-handed circularly polarized light from linearly polarized light;
step S6: in the optical fiber annular cavity, the left-handed circularly polarized light and the right-handed circularly polarized light are oppositely transmitted and then converted into linearly polarized light;
step S7: a part of the clockwise light wave and the anticlockwise light wave are output to the first photoelectric detector and the second photoelectric detector from the optical fiber ring cavity, and the other part of the clockwise light wave and the anticlockwise light wave continue to circulate in the optical fiber ring cavity;
step S8: repeating the steps S5 to S8 by the circular clockwise light wave and the circular anticlockwise light wave;
step S9: and the digital signal processing unit calculates the current information to be measured by detecting the difference between the resonant frequencies of the optical fiber annular cavity in the clockwise direction and the counterclockwise direction.
In an embodiment of the present invention, the specific steps of step S2 are:
the light splitter divides the source light into two beams of light, and the ratio of the light power of the two beams of light is 1;
the specific steps of the step S3 are as follows:
the first electro-optic phase modulator and the second electro-optic phase modulator are used for respectively receiving the two beams of light emitted by the optical splitter and respectively carrying out phase modulation with different frequencies on the two beams of light;
the specific steps of the step S5 are as follows:
converting the clockwise light wave from linearly polarized light into left circularly polarized light or right circularly polarized light through the first polarization control unit and the first lambda/4 wave plate;
converting the anticlockwise light waves into right-handed circularly polarized light or left-handed circularly polarized light from linearly polarized light through the second polarization control unit and the second lambda/4 wave plate;
the specific steps of the step S6 are as follows:
the left-handed circularly polarized light and the right-handed circularly polarized light are oppositely transmitted through the sensing optical fiber, then are converted into linearly polarized light through the second lambda/4 wave plate and the second polarization control unit, and are converted into linearly polarized light through the first lambda/4 wave plate and the first polarization control unit.
In an embodiment of the present invention, in step S9, the information of the current to be measured is calculated by the following formula:
Δf＝Δφ·FSR/2π＝V·N·I·FSR/π
the FSR is the free spectral range of the resonant cavity, the delta f is the difference of the resonant frequencies of the optical fiber ring cavity in the clockwise direction and the anticlockwise direction, and the delta phi is the phase difference generated by the clockwise light wave and the anticlockwise light wave circulating a circle in the optical fiber ring cavity; wherein the content of the first and second substances,
n is the coil turn number of the sensing optical fiber, I is the current information to be measured, R is the coil radius of the sensing optical fiber, V is a Verdet coefficient, H is the magnetic field intensity, and L is the propagation distance.
The invention has the beneficial effects that:
(1) The all-fiber current transformer based on the fiber ring cavity utilizes light to circulate for many times in the fiber ring cavity to improve the sensitivity, can effectively reduce the number of sensing fiber turns wound on a lead, and is favorable for realizing high precision and miniaturization of the all-fiber current transformer.
(2) The all-fiber current transformer based on the fiber ring cavity adopts a narrow-band light source instead of a wide-band light source. Because the Verdet constant has wavelength dependence, the narrow-band light source can inhibit the ratio-changing error of the all-fiber current transformer caused by the central wavelength drift of the light source.
The present invention will be described in further detail with reference to the drawings and examples.
Drawings
Fig. 1 is a schematic structural diagram of an all-fiber current transformer based on a fiber ring cavity according to an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of a fiber ring cavity provided by an embodiment of the present invention;
fig. 3 is a schematic flow chart of a current measurement method of an all-fiber current transformer based on an optical fiber ring cavity according to an embodiment of the present invention.
Description of reference numerals:
1-a light source; 2-a beam splitter; 3-a first electro-optical phase modulator; 4-a second electro-optic phase modulator; 5-a second waveform generator; 6-a first waveform generator; 7-a first optical fiber circulator; 8-a second optical fiber circulator; 9-fiber ring cavity; 10-a first photodetector; 11-a second photodetector; 12-a second synchronous demodulation module; 13-a first synchronous demodulation module; 14-Y branch phase modulation means; 15-a fiber coupler; 16-a second polarization control unit; 17-a second λ/4 plate; 18-a first polarization control unit; 19-a first λ/4 plate; 20-sensing fiber.
Detailed Description
The present invention will be described in further detail with reference to specific examples, but the embodiments of the present invention are not limited thereto.
Example one
As shown in fig. 1, a first aspect of the embodiment of the present invention provides an all-fiber current transformer based on a fiber ring cavity, including: the optical fiber circulator comprises a light source 1, a Y-branch phase modulation device 14, a first optical fiber circulator 7, a second optical fiber circulator 8, an optical fiber ring cavity 9, a first photoelectric detector 10, a second photoelectric detector 11 and a digital signal processing unit.
The Y-branch phase modulation device 14 is configured to divide the source light emitted from the receiving light source 1 into two beams and perform phase modulation on the two beams, respectively. The light source 1 emits a source light wave to the Y-branch phase modulation device 14 through an optical fiber.
The first optical fiber circulator 7 and the second optical fiber circulator 8 are respectively located on two light paths after the phase modulation is carried out by the Y-branch phase modulation device 14, and the first optical fiber circulator 7 is provided with three ports which are respectively connected with the Y-branch phase modulation device 14, the optical fiber ring cavity 9 and the first photoelectric detector 10; the second optical fiber circulator 8 has three ports, which are respectively connected to the Y-branch phase modulation device 14, the optical fiber ring cavity 9, and the second photodetector 11. The optical fiber circulator is connected with each device through optical fibers to carry out light wave transmission.
The optical fiber ring cavity 9 is of a symmetrical structure and forms an annular light path, after two beams of light passing through the first optical fiber circulator 7 and the second optical fiber circulator 8 are coupled to form clockwise light waves and counterclockwise light waves which are transmitted in clockwise and counterclockwise directions, the clockwise light waves and the counterclockwise light waves are converted into linearly polarized light by linearly polarized light after being converted into circularly polarized light, a part of the clockwise light waves and the counterclockwise light waves are output to the first photoelectric detector 10 and the second photoelectric detector 11, the other part of the clockwise light waves and the counterclockwise light waves continue to circulate in the optical fiber ring cavity 9, and the clockwise light waves and the counterclockwise light waves continue to circulate in the optical fiber ring cavity 9 so as to continue to perform polarization state conversion for a next circulation period. The clockwise light wave is a beam of light propagating in the clockwise direction, and the counterclockwise light wave is a beam of light propagating in the counterclockwise direction.
The first photodetector 10 is connected to the digital signal processing unit, and the first photodetector 10 is configured to receive the clockwise light wave output by the optical fiber annular cavity 9. The second photodetector 11 is connected to the digital signal processing unit. The second photodetector 11 is configured to receive the counterclockwise light wave output from the fiber ring cavity 9. The digital signal processing unit is connected with the light source 1, and is configured to demodulate output signals of the first photodetector 10 and the second photodetector 11 to obtain frequency difference information between a clockwise resonant frequency of the optical fiber ring cavity 9 and a light frequency of the light source, obtain frequency difference information between a counterclockwise resonant frequency of the optical fiber ring cavity 9 and the light frequency of the light source, and obtain a difference between the clockwise resonant frequency and the counterclockwise resonant frequency of the optical fiber ring cavity 9 according to the two frequency difference information to obtain current information to be measured.
In this embodiment, based on the all-fiber current transformer in the fiber ring cavity 9, the current information to be measured is obtained by detecting the resonant frequency difference information of the clockwise direction and the counterclockwise direction of the fiber ring cavity 9, and the sensitivity is improved by utilizing multiple ring-shaped in the ring light path of the fiber ring cavity 9, so that the number of 20 turns of the sensing fiber wound on the wire is effectively reduced, and the miniaturization of the current transformer is facilitated. Meanwhile, the narrow-band light source with the line width smaller than 200kHz can be used for inhibiting the ratio-changing error of the all-fiber current transformer caused by the central wavelength drift of the light source.
Example two
As shown in fig. 1 and fig. 2, on the basis of the first embodiment, the present embodiment further defines that the Y-branch phase modulation apparatus 14 includes: a beam splitter 2, a first electro-optical phase modulator 3 and a second electro-optical phase modulator 4. The optical splitter 2 is configured to split the source light emitted by the receiving light source 1 into two beams of light, and two output ports of the optical splitter 2 are respectively connected to the first electro-optical phase modulator 3 and the second electro-optical phase modulator 4. The first electro-optical phase modulator 3 and the second electro-optical phase modulator 4 are configured to receive the two beams of light emitted from the optical splitter 2, and perform phase modulation on the two beams of light. The first electro-optical phase modulator 3 is connected to a first optical fiber circulator 7. The second electro-optical phase modulator 4 is connected to a second optical fiber circulator 8. In this embodiment, the components are connected by optical fibers for light wave transmission.
Further, the fiber ring cavity 9 includes: the optical fiber polarization controller comprises a 2X 2 optical fiber coupler 15, a first polarization control unit 18, a first lambda/4 wave plate 19, a sensing optical fiber 20, a second polarization control unit 16 and a second lambda/4 wave plate 17 which are connected through optical fibers to form a ring-shaped optical path.
A 2 x 2 optical fiber coupler 15 connected with the first optical fiber circulator 7 and the second optical fiber circulator 8 and connected with the first polarization control unit 18; the 2 × 2 optical fiber coupler 15 is used for coupling the two light beams passing through the first optical fiber circulator 7 and the second optical fiber circulator 8 to form clockwise light waves and counterclockwise light waves propagating in clockwise and counterclockwise directions.
A first port of the 2 × 2 optical fiber coupler 15 is connected to the first optical fiber circulator 7, a second port of the 2 × 2 optical fiber coupler 15 is connected to the second optical fiber circulator 8, a third port of the 2 × 2 optical fiber coupler 15 is connected to the first polarization control unit 18, the first polarization control unit 18 is connected to the first λ/4 wave plate 19, the first λ/4 wave plate 19 is connected to the sensing optical fiber 20, the sensing optical fiber 20 is connected to the second λ/4 wave plate 17, the second λ/4 wave plate 17 is connected to the second polarization control unit 16, and the second polarization control unit 16 is connected to a fourth port of the 2 × 2 optical fiber coupler 15.
The first polarization control unit 18, the first lambda/4 wave plate 19, the sensing optical fiber 20, the second lambda/4 wave plate 17 and the second polarization control unit 16 are used for converting both clockwise light waves and anticlockwise light waves into circularly polarized light and then into linearly polarized light. The sensing optical fiber 20 is wound on the measured conductor, and under the action of a magnetic field generated by the current on the conductor, the resonant frequency of the optical fiber annular cavity 9 in the clockwise direction and the counterclockwise direction generates a resonant frequency difference, so that the information of the current to be measured can be determined according to the resonant frequency difference.
Further, a digital signal processing unit comprising: a first waveform generator 6, a second waveform generator 5, a first synchronous demodulation module 13 and a second synchronous demodulation module 12.
The first synchronous demodulation module 13 is connected with the first photoelectric detector 10 and the first waveform generator 6; the first waveform generator 6 is connected to the second phase modulator. The second synchronous demodulation module 12 is connected with the second photoelectric detector 11 and the second waveform generator 5; the second waveform generator 5 is connected to the first phase modulator. The light source 1 is connected to the first synchronous demodulation module 13 or the second synchronous demodulation module 12. In this embodiment, the light source 1 is connected to the second synchronous demodulation module 12, wherein the waveform generator is loaded on the phase modulator for phase modulating the light wave, and is used for the synchronous demodulation module for demodulating the electrical signal output by the photodetector.
In this embodiment, the light source 1 generates two paths of light after passing through the optical splitter 2; the two paths of light enter the optical fiber ring cavity 9 through the 2 x 2 optical fiber coupler 15, so that two paths of light which are transmitted in the clockwise direction and the anticlockwise direction are formed; after entering the fiber annular cavity 9, the two paths of light are converted from linear polarization states into left-handed and right-handed circular polarization states through a lambda/4 wave plate respectively; then the two paths of light pass through the sensing optical fiber 20, and the sensing optical fiber 20 is wound on a current conducting wire to be measured; after passing through the sensing fiber 20, the two paths of light are restored from the left-handed and right-handed circular polarization states to linear polarization states through the lambda/4 wave plate; since the structure of the fiber ring cavity 9 is completely symmetrical (the first polarization control unit 18, the first λ/4 wave plate 19, the second polarization control unit 16 and the second λ/4 wave plate 17 are symmetrically arranged with respect to the sensing fiber 20 and are also symmetrically arranged with respect to the 2 × 2 fiber coupler 15), the linearly polarized light is re-converted into linearly polarized light after one circle of propagation and enters the next ring period. A resonant frequency difference is generated between the resonant frequencies of the optical fiber annular cavity 9 in the clockwise direction and the counterclockwise direction, and the information of the current to be measured can be determined according to the resonant frequency difference.
Further, the sensing fiber 20 is an ultra-low birefringence fiber, a common low birefringence single mode fiber, or a round fiber.
Further, the light source 1 is a narrow-band light source 1, the operating wavelength of the light source 1 is 1550nm, 1310nm, 850nm or 632nm, and the line width is less than 200kHz. Preferably, the light source 1 is a narrow band laser. The all-fiber current transformer based on the fiber ring cavity adopts a narrow-band light source instead of a wide-band light source. Because the Verdet constant has wavelength dependence, the narrow-band light source can inhibit the ratio-changing error of the all-fiber current transformer caused by the central wavelength drift of the light source.
Further, the optical splitter 2 is a 1 × 2 or 2 × 2 polarization maintaining fiber coupler 15, and the optical splitter 2 splits the source light into two beams of light with an optical power ratio of 1. The all-fiber current transformer based on the fiber ring cavity adopts a narrow-band light source instead of a wide-band light source.
Further, the first electro-optical phase modulator 3 and the second electro-optical phase modulator 4 perform phase modulation with different frequencies on the two light waves, and the modulation waveform includes a triangular wave, a sine wave, a sawtooth wave or a trapezoidal wave. The first electro-optical phase modulator 3 and the second electro-optical phase modulator 4 are PZT phase modulators or lithium niobate electro-optical phase modulators.
Further, the 2 × 2 fiber coupler 15 is a polarization maintaining fiber coupler 15, and the splitting ratio thereof is between 1.
Further, the first polarization control unit 18 and the second polarization control unit 16 are single polarization fibers or in-line polarizers.
Further, when the first λ/4 wave plate 19 is welded to the first polarization control unit 18, the polarization axis is rotated by 45 ° and welded; when the second λ/4 plate 17 is fused to the second polarization control unit 16, the polarization axis is fused with a rotation of 45 °.
EXAMPLE III
As shown in fig. 3, a second aspect of the embodiment of the present invention provides a current measuring method for an all-fiber current transformer based on a fiber ring cavity, where the method is applied to a current transformer in the first embodiment or the second embodiment, and includes the following steps:
step S1: the source light wave generated by the light source 1 is incident on the Y-branch phase modulation device 14. Specifically, the light source 1 generates a source light wave incident into the beam splitter 2. The linewidth of the light source 1 is less than 200kHz.
Step S2: the Y-branch phase modulation device 14 divides the source light into two beams, and the ratio of the optical power of the two beams is 1. Specifically, the beam splitter 2 splits the source light into two beams, and the ratio of the optical power of the two beams is 1.
And step S3: the two optical waves are phase-modulated at different frequencies by a Y-branch phase modulation device 14. Specifically, the two beams of light emitted by the optical splitter 2 are received by the first electro-optical phase modulator 3 and the second electro-optical phase modulator 4, respectively, and the two beams of light are subjected to phase modulation with different frequencies, respectively. The modulation waveform comprises a triangular wave, a sine wave, a sawtooth wave or a trapezoidal wave, and the frequencies of the waveforms loaded on the first phase modulator and the second phase modulator are different so as to inhibit back scattering noise and back reflection errors.
And step S4: two beams of light after phase modulation enter the optical fiber ring cavity 9 through the incidence of the first optical fiber circulator 7 and the second optical fiber circulator 8, and form two paths of clockwise light waves and anticlockwise light waves which are transmitted in the clockwise direction and the anticlockwise direction through coupling. Specifically, two light beams enter the optical fiber ring cavity 9, and form two light waves, namely clockwise light waves and counterclockwise light waves which are transmitted in clockwise and counterclockwise directions through the 2 × 2 optical fiber coupler 15 of the optical fiber ring cavity 9.
Step S5: in the optical fiber ring cavity 9, the clockwise light wave and the counterclockwise light wave are respectively converted into left circularly polarized light and right circularly polarized light from linearly polarized light. Specifically, the clockwise light wave is converted from linearly polarized light to left circularly polarized light or right circularly polarized light by the first polarization control unit 18 and the first λ/4 wave plate 19; the counter-clockwise light wave is converted from linearly polarized light to right-handed circularly polarized light or left-handed circularly polarized light by the second polarization control unit 16 and the second λ/4 plate 17.
Step S6: in the fiber ring cavity 9, the left circularly polarized light and the right circularly polarized light are transmitted in opposite directions and then converted into linearly polarized light. Specifically, the left circularly polarized light and the right circularly polarized light are oppositely transmitted through the sensing fiber 20, then converted into linearly polarized light through the second λ/4 wave plate 17 and the second polarization control unit 16, and converted into linearly polarized light through the first λ/4 wave plate 19 and the first polarization control unit 18.
It should be noted that the clockwise light wave circuit sequentially passes through the first polarization control unit 18, the first λ/4 wave plate 19, the sensing fiber 20, the second λ/4 wave plate 17 and the second polarization control unit 16 in a circle, and the polarization state of the clockwise light wave circuit passes through the change of 'linearly polarized light-left-handed circularly polarized light or right-handed circularly polarized light-linearly polarized light'; the counter-clockwise light wave circularly passes through the second polarization control unit 16, the second lambda/4 wave plate 17, the sensing optical fiber 20, the first lambda/4 wave plate 19 and the first polarization control unit 18 in a circle, and the polarization state of the counter-clockwise light wave circularly passes through the change of 'linearly polarized light-rightwise circularly polarized light or leftwise circularly polarized light-linearly polarized light'.
Step S7: after the linearly polarized light passes through the 2 × 2 optical fiber coupler 15, a part of the clockwise light wave and the counterclockwise light wave is output from the optical fiber ring cavity 9 to the first photodetector 10 and the second photodetector 11, and the other part of the clockwise light wave and the counterclockwise light wave continue to circulate in the optical fiber ring cavity 9. Specifically, the clockwise light wave is output to the first photodetector 10, and the counterclockwise light wave is output to the second photodetector 11; the other part of clockwise light wave and anticlockwise light wave continue to circulate in the optical fiber ring cavity 9.
Step S8: and repeating the steps S5 to S7 by the circulating clockwise light wave and the circulating anticlockwise light wave in the step S7, namely outputting one part of the light wave in the optical fiber annular cavity 9 after circulating, continuously circulating the other part of the light wave in the optical fiber annular cavity for the next period, and continuously outputting and circulating the light wave after circulating the next period so as to perform the processes of circulating and outputting for multiple times.
Step S9: the digital signal processing unit calculates the current information to be measured by detecting the difference between the resonant frequencies of the optical fiber annular cavity 9 in the clockwise direction and the counterclockwise direction.
Since the light source 1 can be connected to the first synchronous demodulation module 13 or can also be connected to the second synchronous demodulation module 12, the specific steps of step S9 are slightly different, and are described below:
when the light source 1 is connected to the second synchronous demodulation module 12, the specific steps of step S9 include steps S911 to S914:
step S911: the second photodetector 11 converts the optical signal of the counterclockwise light wave into a first electrical signal, and inputs the first electrical signal to the digital signal processing unit, and the digital signal processing unit obtains first frequency difference information between the resonant frequency of the counterclockwise direction and the light source frequency of the light source 1 according to the first electrical signal. Specifically, the first electrical signal is input to the second synchronous demodulation module 12 of the digital signal processing unit for demodulation, and the second synchronous demodulation module 12 and the second waveform generator 5 acquire first frequency difference information between the counter-clockwise resonance frequency and the light source frequency of the light source 1 according to the first electrical signal.
Step S912: and adjusting the output light frequency of the light source 1 according to the first frequency difference information to ensure that the frequency of the light source 1 is the same as the counter-clockwise resonance frequency. And continuously adjusting the output light frequency of the light source 1 (laser) according to the first frequency difference information so as to dynamically lock the frequency of the light source 1 at the resonant frequency in the counterclockwise direction.
Step S913: the first photodetector 10 converts the received optical signal of the clockwise light wave into a second electrical signal, and inputs the second electrical signal to the digital signal processing unit, and the digital signal processing unit obtains second frequency difference information between the clockwise resonant frequency and the light source frequency according to the second electrical signal. Specifically, the second electrical signal is input to the first synchronous demodulation module 13, and the first synchronous demodulation module 13 and the first waveform generator 6 obtain second frequency difference information between the clockwise resonant frequency and the light source frequency of the light source 1 according to the second electrical signal.
Step S914: and obtaining the current information to be measured according to the difference value of the first frequency difference information and the second frequency difference information. The difference between the first frequency difference information and the second frequency difference information is the difference between the resonant frequencies in the clockwise direction and the counterclockwise direction.
Specifically, the jones matrix of linearly polarized light entering the fiber annular cavity 9 may be written as [ 10 ]] T The linearly polarized light is converted into circularly polarized light after passing through a lambda/4 wave plate, and the Jones matrix can be written as
After the circularly polarized light passes through the sensing fiber 20 wound on the current conducting wire to be measured, the polarization angle is generated due to the action of the magnetic field generated by the current
Where V is the Verdet coefficient, H is the magnetic field strength, L is the propagation distance, and the jones matrix after circularly polarized light passes through the sensing fiber 20 can be written as:
as can be seen from the above formula, the circularly polarized light is still circularly polarized after passing through the sensing fiber 20, but a phase delay is added after the optical rotation, and the phase change amount is
Therefore, the phase difference generated by the clockwise light wave and the counterclockwise light wave circularly moving in the optical fiber annular cavity 9 is:
in the formula, N is the number of turns of the sensing optical fiber 20 coil, I is current information to be measured, and R is the radius of the sensing optical fiber 20 coil. Depending on the nature of the fiber ring cavity, this phase difference Δ φ results in a difference between the resonant frequencies of the fiber ring cavity 9 in the clockwise and counterclockwise directions of:
Δf＝Δφ·FSR/2π＝V·N·I·FSR/π
in the above formula, the FSR is the free spectral range of the fiber ring cavity.
Therefore, the current information I to be measured can be obtained by detecting the difference Δ f between the resonant frequencies in the clockwise direction and the counterclockwise direction, that is, the current information I to be measured can be obtained by detecting the difference between the first frequency difference information and the second frequency difference information.
When the light source 1 is connected to the first synchronous demodulation module 13, the specific steps of step S9 include step S921 to step S924:
step S921: the first photodetector 10 converts the optical signal of the clockwise light wave into a first electrical signal, and inputs the first electrical signal to the digital signal processing unit, and the digital signal processing unit obtains first frequency difference information between the clockwise resonance frequency and the light source frequency of the light source 1 according to the first electrical signal. Specifically, the first electrical signal is input to the first synchronous demodulation module 13 of the digital signal processing unit for demodulation, and the first synchronous demodulation module 13 and the first waveform generator 6 acquire first frequency difference information between the clockwise resonance frequency and the light source frequency of the light source 1 according to the first electrical signal.
Step S922: and adjusting the output light frequency of the light source 1 according to the first frequency difference information to ensure that the frequency of the light source 1 is the same as the clockwise resonance frequency. And continuously adjusting the output light frequency of the light source 1 (laser) according to the first frequency difference information so as to dynamically lock the frequency of the light source 1 at the resonant frequency in the clockwise direction.
Step S923: the second photodetector 11 converts the received optical signal of the counterclockwise light wave into a second electrical signal, and inputs the second electrical signal to the digital signal processing unit, and the digital signal processing unit obtains second frequency difference information between the counterclockwise resonant frequency and the light source frequency according to the second electrical signal. Specifically, the second electrical signal is input to the second synchronous demodulation module 12, and the second synchronous demodulation module 12 and the second waveform generator 5 acquire second frequency difference information between the counter-clockwise resonance frequency and the light source frequency of the light source 1 according to the second electrical signal.
Step S924: and obtaining the information of the current to be measured according to the difference value of the first frequency difference information and the second frequency difference information. The difference between the first frequency difference information and the second frequency difference information is the difference between the resonant frequencies in the clockwise direction and the counterclockwise direction, and thus the current information I is obtained according to the formula Δ f = Δ Φ · FSR/2 pi = V · N · I · FSR/pi.
In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to implicitly indicate the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.
In the present invention, unless otherwise explicitly stated or limited, the terms "mounted," "connected," "fixed," and the like are to be construed broadly, e.g., as being permanently connected, detachably connected, or integral; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples described in this specification can be combined and combined by those skilled in the art.
The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, numerous simple deductions or substitutions may be made without departing from the spirit of the invention, which shall be deemed to belong to the scope of the invention.
Claims (8)
1. An all-fiber current transformer based on an optical fiber ring cavity, comprising: the optical fiber circulator comprises a light source (1), a Y-branch phase modulation device (14), a first optical fiber circulator (7), a second optical fiber circulator (8), an optical fiber ring cavity (9), a first photoelectric detector (10), a second photoelectric detector (11) and a digital signal processing unit; the line width of the light source (1) is less than 200kHz;
the Y-branch phase modulation device (14) is used for dividing source light emitted by the receiving light source (1) into two beams of light and respectively carrying out phase modulation on the two beams of light;
the first optical fiber circulator (7) is located on one optical path of the Y-branch phase modulation device (14) and is connected with the Y-branch phase modulation device (14), the optical fiber annular cavity (9) and the first photoelectric detector (10);
the second optical fiber circulator (8) is positioned on the other optical path of the Y-branch phase modulation device (14) and is connected with the Y-branch phase modulation device (14), the optical fiber annular cavity (9) and the second photoelectric detector (11);
the optical fiber ring cavity (9) is of a symmetrical structure and forms an annular light path, and is used for coupling two beams of light passing through the first optical fiber circulator (7) and the second optical fiber circulator (8) to form clockwise light waves and anticlockwise light waves which are transmitted in clockwise and anticlockwise directions, converting the clockwise light waves and the anticlockwise light waves into linearly polarized light after converting the linearly polarized light into circularly polarized light, and circulating and outputting the clockwise light waves and the anticlockwise light waves for multiple times in the optical fiber ring cavity (9);
the first photoelectric detector (10) is connected with the digital signal processing unit and is used for receiving the clockwise light wave output by the optical fiber annular cavity (9);
the second photoelectric detector (11) is connected with the digital signal processing unit and is used for receiving the anticlockwise light waves output by the optical fiber annular cavity (9);
the digital signal processing unit is connected with the light source (1), and is configured to adjust a frequency of light output by the light source (1), and detect a difference between resonance frequencies in a clockwise direction and a counterclockwise direction of the optical fiber annular cavity (9) according to output signals of the first photodetector (10) and the second photodetector (11), so as to obtain information of the current to be measured.
2. The all-fiber optical current transformer based on the fiber ring cavity of claim 1, wherein the Y-branch phase modulation device (14) comprises: the device comprises a light splitter (2), a first electro-optic phase modulator (3) and a second electro-optic phase modulator (4);
the optical splitter (2) is used for splitting source light emitted by the receiving light source (1) into two beams of light, and the two output ports are respectively connected with the first electro-optical phase modulator (3) and the second electro-optical phase modulator (4);
the first electro-optic phase modulator (3) and the second electro-optic phase modulator (4) are used for respectively receiving the two beams of light emitted by the optical splitter (2) and respectively carrying out phase modulation on the two beams of light;
the first electro-optical phase modulator (3) is connected with the first optical fiber circulator (7);
and the second electro-optical phase modulator (4) is connected with the second optical fiber circulator (8).
3. The all-fiber optical current transformer based on the fiber ring cavity of claim 1, wherein the fiber ring cavity (9) comprises: the polarization control system comprises a 2X 2 optical fiber coupler (15), a first polarization control unit (18), a first lambda/4 wave plate (19), a sensing optical fiber (20), a second polarization control unit (16) and a second lambda/4 wave plate (17), wherein the optical fiber coupler (15), the first lambda/4 wave plate, the sensing optical fiber (20), the second lambda/4 wave plate and the second lambda/4 wave plate are connected through optical fibers to form a ring-shaped optical path;
the 2 x 2 optical fiber coupler (15) is connected with the first optical fiber circulator (7), the second optical fiber circulator (8) and the first polarization control unit (18); the 2 x 2 optical fiber coupler (15) is used for coupling two beams of light passing through the first optical fiber circulator (7) and the second optical fiber circulator (8) to form the clockwise light wave and the anticlockwise light wave which propagate in clockwise and anticlockwise directions;
the first polarization control unit (18) is connected with the first lambda/4 wave plate (19);
the first lambda/4 wave plate (19) is connected with the sensing optical fiber (20);
the sensing optical fiber (20) is connected with the second lambda/4 wave plate (17);
the second lambda/4 wave plate (17) is connected with the second polarization control unit (16) and the 2 x 2 fiber coupler (15);
the first polarization control unit (18), the first lambda/4 wave plate (19), the second lambda/4 wave plate (17) and the second polarization control unit (16) are used for converting the clockwise light wave and the anticlockwise light wave into linearly polarized light after converting the linearly polarized light into circularly polarized light;
the sensing optical fiber (20) is wound on the measured current conducting wire.
4. The all-fiber optical current transformer based on the fiber ring cavity of claim 1, wherein the digital signal processing unit comprises: a first waveform generator (6), a second waveform generator (5), a first synchronous demodulation module (13) and a second synchronous demodulation module (12);
the first synchronous demodulation module (13) is connected with the first photoelectric detector (10) and the first waveform generator (6);
-said first waveform generator (6) connected to said second phase modulator;
the second synchronous demodulation module (12) is connected with the second photoelectric detector (11) and the second waveform generator (5);
-said second waveform generator (5) connected to said first phase modulator;
the light source (1) is connected with the first synchronous demodulation module (13) or the second synchronous demodulation module (12).
5. The all-fiber current transformer based on the fiber ring cavity of claim 3, wherein when the first λ/4 wave plate (19) is welded with the first polarization control unit (18), the polarization axis is rotated by 45 ° to be welded; when the second lambda/4 wave plate (17) is welded with the second polarization control unit (16), the polarization axis is rotated by 45 degrees and welded.
6. A current measuring method of an all-fiber current transformer based on an optical fiber ring cavity, which is applied to the current transformer of any one of claims 1 to 7, and comprises the following steps:
step S1: generating a source light wave by a light source (1) and inputting the source light wave into a Y-branch phase modulation device (14); the line width of the light source (1) is less than 200kHz;
step S2: the Y-branch phase modulation device (14) splits the source light wave into two beams, wherein the ratio of the optical power of the two beams is 1;
and step S3: the two light waves are subjected to phase modulation with different frequencies through the Y-branch phase modulation device (14);
and step S4: two beams of light after phase modulation enter an optical fiber annular cavity (9) through the first optical fiber circulator (7) and the second optical fiber circulator (8) and are coupled to form clockwise light waves and counterclockwise light waves which are transmitted in the clockwise direction and the counterclockwise direction;
step S5: in the optical fiber annular cavity (9), the clockwise light wave and the anticlockwise light wave are respectively converted into left circularly polarized light and right circularly polarized light from linearly polarized light;
step S6: in the optical fiber annular cavity (9), the left circularly polarized light and the right circularly polarized light are oppositely transmitted and then converted into linearly polarized light;
step S7: a part of the clockwise light wave and the anticlockwise light wave are output to the first photoelectric detector (10) and the second photoelectric detector (11) from the optical fiber annular cavity (9), and the other part of the clockwise light wave and the anticlockwise light wave continue to circulate in the optical fiber annular cavity (9);
step S8: repeating the steps S5 to S8 by the circulating clockwise light wave and the circulating anticlockwise light wave;
step S9: and the digital signal processing unit calculates the current information to be measured by detecting the difference between the resonant frequencies of the optical fiber annular cavity (9) in the clockwise direction and the anticlockwise direction.
7. The method for measuring current of the all-fiber current transformer based on the fiber ring cavity according to claim 6, wherein the step S2 comprises the following specific steps:
the light splitter (2) splits the source light wave into two beams of light, and the ratio of the light power of the two beams of light is 1;
the specific steps of the step S3 are as follows:
the first electro-optic phase modulator (3) and the second electro-optic phase modulator (4) are used for respectively receiving the two beams of light emitted by the optical splitter (2) and respectively carrying out phase modulation with different frequencies on the two beams of light;
the specific steps of the step S5 are as follows:
the clockwise light wave is converted into left-handed circularly polarized light or right-handed circularly polarized light from linearly polarized light through the first polarization control unit (18) and the first lambda/4 wave plate (19);
the anticlockwise light wave is converted into right-handed circularly polarized light or left-handed circularly polarized light from linearly polarized light through the second polarization control unit (16) and the second lambda/4 wave plate (17);
the specific steps of the step S6 are as follows:
the left-handed circularly polarized light and the right-handed circularly polarized light are oppositely transmitted through a sensing optical fiber (20), then are converted into linearly polarized light through the second lambda/4 wave plate (17) and the second polarization control unit (16), and are converted into linearly polarized light through the first lambda/4 wave plate (19) and the first polarization control unit (18).
8. The method according to claim 6, wherein in step S9, the current information to be measured is calculated by the following formula:
Δf＝Δφ·FSR/2π＝V·N·I·FSR/π
the FSR is the free spectral range of the resonant cavity, the delta f is the difference of the resonant frequency of the optical fiber annular cavity (9) in the clockwise direction and the counter-clockwise direction, and the delta phi is the phase difference generated by the clockwise light wave and the counter-clockwise light wave circulating for one circle in the optical fiber annular cavity (9); wherein, the first and the second end of the pipe are connected with each other,
n is the number of turns of the coil of the sensing optical fiber (20), I is current information to be measured, R is the coil radius of the sensing optical fiber (20), V is a Verdet coefficient, H is the magnetic field intensity, and L is the propagation distance.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204008793U (en) * | 2014-07-15 | 2014-12-10 | 鞍山博丰电力设备有限公司 | A kind of mid point manifold type optical fiber current mutual inductor |
| CN104597304A (en) * | 2015-01-07 | 2015-05-06 | 贵州电力试验研究院 | Ring cavity type all-fiber current sensor |
| CN204479632U (en) * | 2015-01-07 | 2015-07-15 | 贵州电力试验研究院 | A kind of annular cavate all-fiber current sensor |
| CN110927431A (en) * | 2019-12-12 | 2020-03-27 | 东南大学 | Closed-loop demodulation all-fiber current transformer and large-current waveform hopping problem solving method thereof |
| WO2020087423A1 (en) * | 2018-10-31 | 2020-05-07 | 浙江大学 | Bidirectional optical-carrying microwave resonance system based on circulator structure and method for detecting angular velocity by said system |
-
2022
- 2022-06-10 CN CN202210655335.1A patent/CN115184661A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204008793U (en) * | 2014-07-15 | 2014-12-10 | 鞍山博丰电力设备有限公司 | A kind of mid point manifold type optical fiber current mutual inductor |
| CN104597304A (en) * | 2015-01-07 | 2015-05-06 | 贵州电力试验研究院 | Ring cavity type all-fiber current sensor |
| CN204479632U (en) * | 2015-01-07 | 2015-07-15 | 贵州电力试验研究院 | A kind of annular cavate all-fiber current sensor |
| WO2020087423A1 (en) * | 2018-10-31 | 2020-05-07 | 浙江大学 | Bidirectional optical-carrying microwave resonance system based on circulator structure and method for detecting angular velocity by said system |
| CN110927431A (en) * | 2019-12-12 | 2020-03-27 | 东南大学 | Closed-loop demodulation all-fiber current transformer and large-current waveform hopping problem solving method thereof |
Non-Patent Citations (6)
| Title |
|---|
| ZHIGUO JIANG: "Residual Intensity Modulation Induced Error in Resonator Fiber Optic Gyroscopes With Reciprocal Detection", 《IEEE PHOTONICS JOURNAL》, 18 May 2021 (2021-05-18) * |
| 张昊: "一种环形结构单光路检测型光纤电流传感器", 《激光与光电子学进展》, 10 January 2018 (2018-01-10) * |
| 张昊: "环形结构全光纤电流传感器研究", 《中国优秀博士学位论文全文数据库 信息科技辑》, 15 March 2015 (2015-03-15) * |
| 蒋俊贞;张昊;何友武;邱怡申;: "基于时分复用的多点式环形腔光纤电流传感器", 光子学报, no. 12, 31 December 2017 (2017-12-31) * |
| 赵晶晶, 冯丽爽, 张春熹: "全光纤波片对光纤电流互感器件性能的影响", 光学技术, no. 06, 20 November 2005 (2005-11-20) * |
| 黄爱显: "基于光纤环技术的全光纤电流传感器研究", 《中国优秀硕士学位论文全文数据库 信息科技辑》, 15 February 2014 (2014-02-15) * |
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