Distributed optical fiber current measurement system and measurement method based on optical switch

Abstract

The invention discloses a distributed optical fiber current measuring system and measuring method based on an optical switch, and the system is mainly connected with a photoelectric signal processing unit and an array formed by a plurality of optical fiber current sensitive rings through a 1 * N optical switch, the photoelectric signal processing unit is used for generating orthogonal line polarized light, and the optical fiber current sensitive rings are used for receiving the orthogonal line polarized light. A signal of measuring current of the sensing ring unit is demodulated through polarization conversion and a reflection mechanism, and a time sequence control signal is generated, so that the optical switch is driven to be sequentially communicated with measuring loops of different optical fiber current sensing rings in a time-sharing manner, and polling measurement of N measuring loops is realized. By introducing the light splitting device, the number of the photoelectric detection units can be reduced from N to 1, and the measurement cost is effectively reduced while the current measurement precision is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of current measurement, and more particularly to a distributed optical fiber current measurement system and a measurement method based on an optical switch. Background Art

[0002] In the metallurgical industry, during the production process of aluminum smelters, the DC electrolysis current is generally as high as 300kA. As an important indicator for evaluating the quality of aluminum smelters and the energy conservation and emission reduction level of production enterprises, DC unit consumption has a significant impact on the production efficiency and economic benefits of enterprises. Therefore, accurate measurement of electrolysis current is of great significance for improving production efficiency and reducing costs.

[0003] At present, the current measurement methods commonly used in the electrolytic metallurgy industry are mainly the equidistant voltage drop method and the Hall sensor method. However, these two methods have the following limitations:

[0004] (1) Poor measurement accuracy: The equidistant voltage drop method is easily affected by factors such as line resistance and contact resistance, resulting in low measurement accuracy; the Hall sensor method is greatly affected by external magnetic fields, which also affects the measurement accuracy;

[0005] (2) Insufficient real-time monitoring capabilities: Traditional measurement methods cannot effectively monitor the status of the electrolytic cell in real time, which is not conducive to timely adjustment of the process.

[0006] Therefore, how to solve the above problems and meet the needs of industrial DC current measurement such as electrolytic metallurgy is an urgent problem that technical personnel in this field need to solve. Summary of the invention

[0007] In view of this, the present invention provides a distributed optical fiber current measurement system and measurement method based on an optical switch, which are used to ensure measurement accuracy while effectively reducing measurement costs, reducing volume and power consumption, and improving real-time monitoring capabilities.

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] On the one hand, the present application provides a distributed optical fiber current measurement system based on optical switches, the system comprising an optical fiber current sensitive ring array, each optical fiber current sensitive ring in the array is connected to an optoelectronic signal processing unit through a 1×N optical switch;

[0010] The optoelectronic signal processing unit is used to generate orthogonal linear polarized light, demodulate the signal of the sensitive ring unit measuring current through polarization conversion and reflection mechanism, and generate a timing control signal to drive the optical switch to connect the measurement loops of different optical fiber current sensitive loops in time-sharing order, so as to realize the polling measurement of N measurement loops.

[0011] Preferably, the 1×N optical switch is connected to the optoelectronic signal processing unit and the optical fiber current sensitive ring array by optical fiber fusion splicing or jumper wires.

[0012] Preferably, the 1×N optical switch is a mechanical optical switch, an electro-optical optical switch or a thermo-optical optical switch.

[0013] Preferably, the number of channels of the 1×N optical switch is 4, 8, 16, 32, 64 or 128.

[0014] Preferably, the optoelectronic signal processing unit includes an SLD light source, a spectrometer, a detector, a phase modulator, a delay fiber ring, and a signal detection circuit board; wherein,

[0015] The SLD light source is connected to the optical splitter, and the other end of the optical splitter is connected to the delay optical fiber ring through the phase modulator, and is connected to the phase modulator through the detector and the signal detection circuit board.

[0016] Preferably, a fiber polarizer is connected between the optical splitter and the phase modulator, and a polarization-maintaining coupler is connected between the phase modulator and the delay fiber ring.

[0017] Preferably, the fiber optic current sensitive ring comprises a wave plate, a sensing fiber and a reflector assembly which are connected in sequence, and the reflector assembly is flexibly docked with the wave plate or fixedly packaged.

[0018] Preferably, when the reflector assembly is flexibly docked with the wave plate, the wave plate is fixed in a docking box, and the reflector is detachably installed in the docking box, wherein the docking box has a mounting groove matching the shape of the reflector for aligning the reflector with the wave plate.

[0019] Preferably, a wave plate cover is provided above the wave plate, and a sealing gasket is provided between the wave plate and the wave plate cover; a box cover is provided above the docking box, one end of the box cover is connected to the docking box body through a rotatable structure, and when the box cover and the box body are closed, they are fixed by screws.

[0020] On the other hand, the present application discloses a distributed optical fiber current measurement method based on an optical switch, the method using the distributed optical fiber current measurement system based on an optical switch as described in any one of the above items, the measurement steps comprising:

[0021] S1, connecting multiple optical fiber current sensitive rings to an optoelectronic signal processing unit through a 1×N optical switch;

[0022] S2, generating orthogonal linear polarized light and timing control signals through an optoelectronic signal processing unit;

[0023] By using orthogonal linear polarized light, the signal of the current measured by the sensitive ring unit is demodulated through polarization conversion and reflection mechanism, and the optical switch is driven to connect the measurement loops of different optical fiber current sensitive rings in turn through the timing control signal, so as to realize the polling measurement of N measurement loops.

[0024] Through the above technical solutions, it can be known that the present invention discloses a distributed optical fiber current measurement system and measurement method based on optical switches, which can effectively solve the problem of accurate measurement of multi-point DC current in industrial scenarios such as electrolytic metallurgy. Compared with the prior art, by introducing a splitter device, time-division multiplexing technology is realized. When measuring multi-channel current signals, the number of photoelectric detection units can be reduced from N to 1, which effectively reduces the measurement cost while ensuring the current measurement accuracy;

[0025] The optical splitter can select different numbers of paths to meet different measurement requirements, with a flexible structure, while also greatly reducing the size and power consumption of the measurement system;

[0026] At the same time, the flexibly connected fiber optic current sensitive ring of the present application has the advantages of quick disassembly and installation, and rapid self-alignment. It is lighter and more compact than the existing fiber optic current sensitive unit, and can achieve measurement without cutting off the detected line. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0028] Figure 1 This is a structural diagram of a distributed optical fiber current measurement system based on an optical switch of the present invention;

[0029] Figure 2 This is a structural diagram of a photoelectric signal detection unit using a polarizer and a phase modulator in the present invention;

[0030] Figure 3 This is a structural diagram of a photoelectric signal detection unit using a phase modulator and a polarization-maintaining coupler of the present invention;

[0031] Figure 4 It is a principle diagram of the optical fiber sensitive loop of the present invention;

[0032] Figure 5 This is a schematic diagram of the three-dimensional explosion structure of the optical fiber current sensitive ring of the present invention;

[0033] Figure 6 This is a structural diagram of the optical fiber current sensitive reflector assembly provided by the present invention. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] At present, fiber optic current sensors are gradually being used in the electrolytic metallurgical industry due to their strong anti-interference ability, fast response speed, and wide measurement range. However, the existing fiber optic current measurement system needs to be equipped with a large number of photoelectric detection units when measuring multi-channel current signals, resulting in high cost, bulky size, and increased power consumption.

[0036] In this regard, the embodiment of the present invention first discloses a distributed optical fiber current measurement system based on an optical switch. The system introduces a splitter device based on a traditional optical fiber current sensor unit to realize time-division multiplexing technology; the measurement principle is: the timing control signal generated in the signal detection unit drives the optical switch to sequentially connect different measurement loops in time-division as required, thereby realizing polling measurement of N measurement loops.

[0037] When the present application measures multi-channel current signals, the number of photoelectric detection units can be reduced from N to 1, which effectively reduces the measurement cost while ensuring the current measurement accuracy. The spectrometer can select different numbers of channels to correspond to different measurement requirements, with a flexible structure. At the same time, it also greatly reduces the volume and power consumption of the measurement system.

[0038] In one embodiment, referring to Figure 1 The distributed optical fiber current measurement system of the present invention comprises an optical fiber current sensitive ring array, a 1×N optical switch and an optoelectronic signal processing unit, wherein each optical fiber current sensitive ring in the array is connected to the optoelectronic signal processing unit through a 1×N optical switch;

[0039] The photoelectric signal processing unit is used to generate orthogonal linear polarized light, and demodulate the signal of the current measured by the sensitive ring unit through polarization conversion and reflection mechanism. The two beams of orthogonal linear polarized light generated by the photoelectric signal detection unit enter the optical switch, and enter different sensitive ring units respectively after the time-sharing switching function of the optical switch. In the sensitive ring unit, the orthogonal linear polarized light is converted into left-handed circular polarized light and right-handed circular polarized light. The magnetic field generated by the sensitive current generates a Faraday phase difference, and the left-handed circular polarized light and the right-handed circular polarized light are transmitted to the reflector. The polarization states of the circular polarized light and the right-handed circular polarized light are reversed by the reflector and returned along the original optical path, and then returned to the photoelectric signal detection unit again, so as to realize the demodulation of the current measured by this sensitive ring.

[0040] And generate a timing control signal to drive the optical switch to connect the measurement loops of different optical fiber current sensitive rings in turn in time division to achieve polling measurement of N measurement loops; the present invention can achieve the measurement of the current of each sensitive ring unit through the switching of the optical switch.

[0041] In one embodiment, the 1×N optical switch is connected to the optoelectronic signal processing unit and the optical fiber current sensitive ring array by means of optical fiber fusion splicing or optical fiber jumper.

[0042] The 1×N optical switch is a mechanical optical switch, an electro-optical optical switch or a thermo-optical optical switch, preferably a mechanical or MEME principle polarization-maintaining optical switch. Based on measurement requirements, the number of channels of the 1×N optical switch can be 4, 8, 16, 32, 64 or 128.

[0043] In one embodiment, the optoelectronic signal processing unit includes an SLD light source, a beam splitter, a detector, a phase modulator, a delay fiber ring, and a signal detection circuit board; wherein the beam splitter is a circulator or a coupler.

[0044] In this embodiment, the SLD light source is connected to the optical splitter, the other end of the optical splitter is connected to the delay fiber ring through a phase modulator, and the detector and the signal detection circuit board are connected to the phase modulator.

[0045] Furthermore, if Figure 2 and Figure 3 A fiber polarizer is connected between the beam splitter and the phase modulator to convert polarized light into light with a specific polarization state; or a polarization-maintaining coupler is connected between the phase modulator and the delay fiber ring to combine optical signals from two or more input ports into one output port to maintain the polarization state of the optical signal.

[0046] In this embodiment, the signal detection circuit board includes a preamplifier module, an A / D conversion module, a digital signal processing module and a D / A conversion module connected in sequence, wherein the preamplifier module is connected to the detector, and the D / A conversion module is connected to the phase modulator.

[0047] The optical signal can be converted into a digital signal through the preamplifier module and the A / D conversion module to accurately control the current sampling time point and sampling period. Then, the digital signal is converted back to an analog signal (D / A conversion) and transmitted to the phase modulator. At this stage, a closed-loop feedback mechanism can be used to adjust the timing control signal, that is, by monitoring the quality of the output signal, the sampling rate, conversion time and processing delay can be dynamically adjusted to optimize the overall performance.

[0048] In order to further optimize the above technical solution, the digital signal processing module is connected to the host computer so that the measured current data can be displayed in real time through the host computer, and the data can be stored and played back.

[0049] In one embodiment, if Figure 4 The optical fiber current sensitive ring includes a wave plate, a sensing optical fiber and a reflector assembly which are connected in sequence. The reflector assembly is flexibly docked with the wave plate or fixedly packaged.

[0050] When the reflector assembly is flexibly connected to the wave plate, Figure 5 The wave plate 11 is fixed in the docking box 2, and the reflector assembly 6 is detachably installed in the docking box. When it is necessary to detect the current, the reflector assembly 6 is first taken out from the docking box 2, the sensitive optical cable is wound around the object to be detected, and finally the reflector assembly 6 is placed in the docking box 2; wherein, there is an installation groove in the docking box that matches the shape of the reflector, which is used to realize the alignment of the reflector and the wave plate.

[0051] A wave plate cover plate 8 is provided above the wave plate 11, and a sealing gasket 10 is provided between the wave plate 11 and the wave plate cover plate 8, wherein the wave plate cover plate 8 and the sealing gasket 10 are fixed to the docking box 2 by screws 9; a box cover plate 3 is provided above the docking box 2, and one end of the box cover plate 3 is connected to the box body of the docking box 2 by a rotatable structure, and the box cover plate 3 is fixed to the box body by screws when it is closed. In one embodiment, the cover plate 3 is connected to the docking box 2 by a pin 7, allowing the user to lift the cover in the up and down direction to open it, or rotate the cover in the horizontal direction to open it (this opening method is not shown), and two hand screws 4 are provided at the opening and closing end of the cover plate 3 to facilitate the quick opening of the cover plate 3, so as to realize the quick removal and installation of the reflector assembly 6.

[0052] In this embodiment, the reflector assembly 6 is located at one end of the sensitive optical cable 5. Figure 6 The transmitting mirror assembly 6 includes a reflector 6-1 and a reflector housing 6-2, wherein the reflector 6-1 is wrapped with the reflector housing 6-2. In this embodiment, the reflector 6-1 is realized by plating a high reverse mold on the end face of the sensitive optical cable 5, and the reflector housing 6-2 is made of plastic material, and is integrally injection molded together with the reflector 6-1 and the sensitive optical cable 5 to achieve sealing of the reflector 6-1 and the sensitive optical cable 5.

[0053] In another embodiment, the present application discloses a distributed optical fiber current measurement method based on an optical switch, the method using the distributed optical fiber current measurement system based on an optical switch as described in any one of the above items, the measurement steps comprising:

[0054] S1, connecting multiple optical fiber current sensitive rings to an optoelectronic signal processing unit through a 1×N optical switch;

[0055] S2, generating orthogonal linear polarized light and timing control signals through an optoelectronic signal processing unit;

[0056] By using orthogonal linear polarized light, the signal of the current measured by the sensitive ring unit is demodulated through polarization conversion and reflection mechanism, and the optical switch is driven to connect the measurement loops of different optical fiber current sensitive rings in turn through the timing control signal, so as to realize the polling measurement of N measurement loops.

[0057] The optical fiber current measurement system using optical switching in the patent application has the advantages of good insulation performance, strong anti-electromagnetic interference ability, high measurement accuracy, small size, light weight, large measurement dynamic range, wide frequency band, etc. It is also flexible in installation and can be installed without cutting off the power supply of the detected line. It can also display the current value in real time, provide effective data for the monitoring of the electrolytic cell status, and can also store and playback related data, which is very suitable for industrial DC current measurement such as electrolytic metallurgy.

[0058] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0059] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A distributed optical fiber current measurement system based on optical switches, characterized in that: It includes an optical fiber current sensitive ring array, each optical fiber current sensitive ring in the array is connected to an optoelectronic signal processing unit through a 1×N optical switch; The optoelectronic signal processing unit is used to generate orthogonal linear polarized light, demodulate the signal of the sensitive ring unit measuring current through polarization conversion and reflection mechanism, and generate a timing control signal to drive the optical switch to connect the measurement loops of different optical fiber current sensitive loops in time-sharing order, so as to realize the polling measurement of N measurement loops.

2. A distributed optical fiber current measurement system based on optical switches according to claim 1, characterized in that: The 1×N optical switch is connected to the optoelectronic signal processing unit and the optical fiber current sensitive ring array by optical fiber fusion splicing or jumper wires.

3. The distributed optical fiber current measurement system based on optical switch according to claim 1, characterized in that: The 1×N optical switch is a mechanical optical switch, an electro-optical optical switch or a thermal-optical optical switch.

4. The distributed optical fiber current measurement system based on optical switch according to claim 1, characterized in that: The number of channels of a 1×N optical switch is 4, 8, 16, 32, 64 or 128.

5. The distributed optical fiber current measurement system based on optical switch according to claim 1, characterized in that: The optoelectronic signal processing unit includes an SLD light source, a spectrometer, a detector, a phase modulator, a delay fiber ring, and a signal detection circuit board; wherein, The SLD light source is connected to the optical splitter, and the other end of the optical splitter is connected to the delay optical fiber ring through the phase modulator, and is connected to the phase modulator through the detector and the signal detection circuit board.

6. The distributed optical fiber current measurement system based on optical switch according to claim 5, characterized in that: A fiber polarizer is connected between the optical splitter and the phase modulator, and a polarization-maintaining coupler is connected between the phase modulator and the delay fiber ring.

7. The distributed optical fiber current measurement system based on optical switch according to claim 1, characterized in that: The optical fiber current sensitive ring comprises a wave plate, a sensing optical fiber and a reflector assembly which are connected in sequence. The reflector assembly is flexibly docked with the wave plate or fixedly packaged.

8. The distributed optical fiber current measurement system based on optical switch according to claim 7, characterized in that: When the reflector assembly is flexibly docked with the wave plate, the wave plate is fixed in the docking box, and the reflector is detachably installed in the docking box, wherein the docking box has an installation groove matching the shape of the reflector for aligning the reflector with the wave plate.

9. The distributed optical fiber current measurement system based on optical switch according to claim 8, characterized in that: A wave plate cover is provided above the wave plate, and a sealing gasket is provided between the wave plate and the wave plate cover; A box cover is provided above the docking box, one end of which is connected to the docking box body through a rotatable structure, and when the box cover is closed, it is fixed to the box body through screws.

10. A distributed optical fiber current measurement method based on an optical switch, characterized in that: The distributed optical fiber current measurement system based on an optical switch according to any one of claims 1 to 9 is applied, and the measurement step comprises: S1, connecting multiple optical fiber current sensitive rings to an optoelectronic signal processing unit through a 1×N optical switch; S2, generating orthogonal linear polarized light and timing control signals through an optoelectronic signal processing unit; By using orthogonal linear polarized light, the signal of the current measured by the sensitive ring unit is demodulated through polarization conversion and reflection mechanism, and the optical switch is driven to connect the measurement loops of different optical fiber current sensitive rings in turn through the timing control signal, thereby realizing polling measurement of N measurement loops.

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