Optical fiber sensing probe, detection device and detection method

Abstract

The invention provides an optical fiber sensing probe, a detection device and a detection method, and belongs to the technical field of environmental parameter detection. The optical fiber sensing probe comprises a base and a temperature sensing assembly, a plurality of guide rods which are arranged in parallel at intervals are arranged on the base, and electrified contacts are arranged at the tail ends of the guide rods. The temperature sensing assembly comprises a fiber bragg grating, a leading-out optical fiber, a plastic hose and a plurality of metal pipes, the metal pipes are connected to the electrified contacts at the tail ends of the guide rods in a one-to-one correspondence mode, the metal pipes are connected through the plastic hose, and the other end of one metal pipe is connected with the base through the plastic hose; the leading-out optical fiber penetrates through the plastic hose and the metal tubes, and the fiber bragg grating is arranged on the leading-out optical fiber in the metal tubes. Accurate temperature sensing and detection can be realized in an area with a complex electromagnetic environment under the condition that a detected object is electrified.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental parameter detection, and in particular to an optical fiber sensing probe, a detection device and a detection method. Background Art

[0002] High-voltage current transformers are used to convert high currents into standard low currents in proportion to achieve standardization and miniaturization of measuring instruments, protection equipment, and automatic control equipment. Transformers can also be used to isolate high-voltage systems to ensure personal and equipment safety. The stability and accuracy level of high-voltage current transformers directly affect the measurement precision and accuracy of measuring instruments. Therefore, high-voltage current transformers need to be strictly calibrated before use.

[0003] In the related art, for a high-voltage current transformer, its specific structure generally includes a transformer body, a mounting base arranged at the bottom of the body, an induction coil arranged inside the transformer, a primary side terminal arranged at the top of the body, and a secondary side terminal arranged at the bottom of the body. Among them, the existing verification method usually adopts a contact corresponding to the primary side terminal to connect with the primary side terminal to detect its output signal under power.

[0004] When the calibration method in the related technology is used, the temperature of the contacts rises during the calibration process when they are in contact with the transformer terminals. After long-term use, there is a safety hazard of high-temperature fire, and the working temperature of the contact position needs to be detected and controlled. For the corresponding transformer terminals, the number of contacts is usually plural, and they are in a complex electromagnetic environment with live operation. There are electromagnetic interference and other influences on traditional temperature sensors. The existing structure and layout of temperature sensors make it difficult to measure the temperature at multiple live points while ensuring the insulation of the cross-connection, and to ensure the detection accuracy in a harsh electromagnetic environment. Summary of the invention

[0005] The embodiment of the present invention provides an optical fiber sensor probe, a detection device and a detection method, which can ensure accurate temperature perception and detection in areas with complex electromagnetic environments when the object being measured is charged. The technical solution is as follows:

[0006] In a first aspect, an embodiment of the present invention provides a fiber optic sensing probe, comprising: a base and a temperature sensing component,

[0007] The base is provided with a plurality of guide rods arranged in parallel and at intervals, and the ends of the guide rods are provided with live contacts;

[0008] The temperature sensing component includes a fiber grating, an output optical fiber, a plastic hose, and a plurality of metal tubes. The plurality of metal tubes are connected one by one to the electrified contacts at the ends of the plurality of guide rods. The plurality of metal tubes are connected to each other through the plastic hose. The other end of one of the metal tubes is connected to the base through the plastic hose. The output optical fiber is passed through the plastic hose and the plurality of metal tubes. The fiber grating is arranged on the output optical fiber in the metal tube.

[0009] Optionally, the guide rod is telescopically connected to the base.

[0010] Optionally, the plastic hose located between the metal tube and the base is spirally wound around the outer rings of the plurality of guide rods.

[0011] Optionally, a heat shrink tube is further included, the end of the plastic hose is inserted into the end opening of the metal tube, and the heat shrink tube is fixedly sleeved on the outer wall of the connection between the plastic hose and the metal tube.

[0012] Optionally, the lead-out optical fiber passing through the metal tube is fixedly connected to the inner wall of the metal tube by filling epoxy resin.

[0013] Optionally, the metal tube and the live contact are fixed by spot welding.

[0014] Optionally, the live contact is detachably connected to the guide rod.

[0015] Optionally, the metal tube is a stainless steel tube or a brass tube.

[0016] Optionally, the plastic hose is a polytetrafluoroethylene hose.

[0017] In a second aspect, an embodiment of the present invention provides a detection device, comprising a plurality of optical fiber sensor probes as described in the first aspect, and also comprising a coupler, a demodulator and a host computer, wherein the plurality of optical fiber sensor probes are arranged in an array, and the output optical fibers of the plurality of optical fiber sensor probes are connected to the demodulator via the coupler, and the demodulator is connected to the host computer.

[0018] In a third aspect, the present invention further provides a detection method, which is implemented based on the detection device described in the second aspect, comprising:

[0019] The current transformer to be tested is installed below the plurality of optical fiber sensing probes;

[0020] Adjusting the height of the guide rod and the live contact on the base so that the live contact is butted against the primary side terminal on the top of the current transformer;

[0021] While the current transformer is working, the fiber grating is used to change the wavelength of the reflected light corresponding to the temperature change at the live contact, and the optical signal is transmitted by the export optical fiber to the host computer through the coupler and the demodulator to detect and display the temperature.

[0022] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0023] The optical fiber sensing probe provided by the embodiment of the present invention is provided with a metal tube with a built-in optical fiber Bragg grating on the live contact conventionally used for docking with the primary terminal of the current transformer, and the lead-out optical fiber inserted in the multiple metal tubes is encapsulated and led out through a plastic hose, so that the lead-out optical fiber is docked with an external detection device. When the live contact is used to detect the output signal of the current transformer, the optical fiber Bragg grating is used to sense the temperature change at the live contact, and the optical signal is transmitted to the external detection device using the lead-out optical fiber to sense and detect the working temperature of the live contact. The optical fiber material is used as an electrical insulator and does not conduct electricity, and the performance of the transmitted optical signal is not affected in a harsh electromagnetic environment. It can ensure accurate temperature perception and detection in the case of a live object and in an area with a complex electromagnetic environment, thereby ensuring the safe operation of the current transformer calibration process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 is a front structural schematic diagram of an optical fiber sensing probe provided by an embodiment of the present invention;

[0026] Figure 2 is a schematic diagram of the back structure of the optical fiber sensing probe provided by an embodiment of the present invention;

[0027] Figure 3 It is a schematic diagram of the connection structure of a plastic hose and a metal pipe provided by an embodiment of the present invention;

[0028] Figure 4 is a partial structural cross-sectional view of an optical fiber sensing probe provided by an embodiment of the present invention;

[0029] Figure 5 is a schematic diagram of the working state of the optical fiber sensing probe provided by an embodiment of the present invention;

[0030] Figure 6is a schematic structural diagram of a detection device provided by an embodiment of the present invention;

[0031] Figure 7 It is a flow chart of a detection method provided by an embodiment of the present invention.

[0032] In the figure:

[0033] 1-base; 2-temperature sensing component; 3-heat shrink tube; 4-coupler; 5-demodulator; 6-host computer; 11-guide rod; 12-powered contact; 21-fiber grating; 22-output optical fiber; 23-plastic hose; 24-metal tube; a-epoxy resin; m-current transformer. DETAILED DESCRIPTION

[0034] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0035] Embodiment 1:

[0036] Figure 1 is a front structural schematic diagram of an optical fiber sensing probe provided by an embodiment of the present invention; Figure 2 is a schematic diagram of the back structure of the optical fiber sensing probe provided by an embodiment of the present invention; Figure 3 It is a schematic diagram of the connection structure of a plastic hose and a metal pipe provided by an embodiment of the present invention; Figure 4 is a partial structural cross-sectional view of an optical fiber sensing probe provided by an embodiment of the present invention; Figure 5 FIG. 1 is a schematic diagram of the working state of the optical fiber sensor probe provided by an embodiment of the present invention. Figures 1 to 5 As shown, an embodiment of the present invention provides a fiber optic sensing probe, including a base 1 and a temperature sensing component 2.

[0037] Among them, a plurality of parallel and spaced guide rods 11 are arranged on the base 1, and a live contact 12 is arranged at the end of the guide rod 11. The temperature sensing component 2 includes a fiber grating 21, an output optical fiber 22, a plastic hose 23, and a plurality of metal tubes 24. The plurality of metal tubes 24 are connected to the live contacts 12 at the ends of the plurality of guide rods 11 in a one-to-one correspondence, and the plurality of metal tubes 24 are connected through the plastic hose 23, and the other end of one of the metal tubes 24 is connected to the base 1 through the plastic hose 23, the output optical fiber 22 is inserted into the plastic hose 23 and the plurality of metal tubes 24, and the fiber grating 21 is arranged on the output optical fiber 22 in the metal tube 24.

[0038] In the embodiment of the present invention, the optical fiber sensor probe is suspended upside down above the current transformer m to be measured during operation, and its guide rod 11 and the live contact 12 at the end face the primary side terminal at the top of the current transformer m. The staff adjusts the height of the guide rod 11 and the live contact 12 on the base 1 so that the live contact 12 is docked with the primary side terminal at the top of the current transformer m to complete the installation of the optical fiber sensor probe. Each live contact 12 is fixedly connected to a metal tube 24 on the side, and multiple metal tubes 24 are connected in sequence through plastic hoses 23, and one of the metal tubes 24 located at the outermost outlet is used as the lead-out end to set the plastic hose 23 upwardly connected to the base 1, and the lead-out optical fiber 22 is arranged in the plastic hose 23 and multiple metal tubes 24 and connected to the optical fiber grating 21 in the multiple metal tubes 24, and finally the plastic hose 23 at the lead-out end is led out to connect the signal with the demodulator 5 and the host computer 6 and other detection equipment arranged outside. When the operation verification test of the current transformer m is performed, while the current transformer m is conducting with the live contact 12 as the test equipment, the fiber grating 21 is used to change the wavelength of the reflected light corresponding to the temperature change at the live contact 12, and the optical signal is transmitted to the host computer 6 through the demodulator 5 by the lead-out optical fiber 22, so as to detect and display the temperature at the position of the live contact 12, so as to facilitate the detection by the staff.

[0039] The optical fiber sensing probe provided by the embodiment of the present invention is provided with a metal tube 24 with a built-in optical fiber grating 21 on the live contact 12 conventionally used for docking with the primary terminal of the current transformer m, and the lead-out optical fiber 22 penetrating the multiple metal tubes 24 is encapsulated and led out through a plastic hose 23 so that the lead-out optical fiber 22 can be docked with an external detection device. When the live contact 12 is used to detect the output signal of the current transformer m, the optical fiber grating 21 is used to sense the temperature change at the live contact 12, and the optical signal is transmitted to the external detection device by the lead-out optical fiber 22 to sense and detect the working temperature of the live contact 12. The optical fiber material is used as an electrical insulator and does not conduct electricity, and the performance of the transmitted optical signal is not affected in a harsh electromagnetic environment. It can ensure that when the object to be measured is charged, it can achieve accurate temperature perception and detection in areas with complex electromagnetic environments, and ensure the safe operation of the calibration process of the current transformer m.

[0040] Optionally, the guide rod 11 is telescopically connected to the base 1. Exemplarily, in an embodiment of the present invention, the guide rod 11 is a telescopic structure relative to the base 1, for example, the base 1 and the guide rod 11 are an integral cylinder or electric cylinder structure, and the guide rod 11 is a telescopic rod on the base 1. Through the driving structure inside the base 1, the guide rod 11 can be driven to perform lifting activities in the vertical direction to adjust the relative position between the live contact 12 and the current transformer m below, realize automatic conduction and disconnection, reduce the overall movement and manual adjustment of the optical fiber sensor probe, and drive the live contact 12 to adjust the position through the guide rod 11, so as to facilitate frequent position adjustments and adapt to some narrow measurement spaces.

[0041] Optionally, the plastic hose 23 between the metal tube 24 and the base 1 is spirally wound around the outer rings of the multiple guide rods 11. For example, in an embodiment of the present invention, the plastic hose 23 used to connect the metal tube 24 and the base 1 to lead out the optical fiber 22 is arranged in a spirally wound manner on the multiple guide rods 11, avoiding redundant settings on a single side, making the structure of the entire optical fiber sensor probe compact and convenient for array arrangement in a small space. Furthermore, during the reciprocating telescopic movement of the guide rod 11, the spiral arrangement structure of the plastic hose 23 can ensure a certain damping, reduce the amplitude of the internally encapsulated optical fiber 22 during the movement, reduce the shear stress on the optical fiber structure, and ensure that the overall structure of the probe has sufficient elastic strength and service life to adapt to the dynamic changes of the system.

[0042] Optionally, a heat shrink tube 3 is further included, and the end of the plastic hose 23 is inserted into the end opening of the metal tube 24, and the heat shrink tube 3 is fixedly sleeved on the outer wall of the connection between the plastic hose 23 and the metal tube 24. Exemplarily, in the embodiment of the present invention, the outer diameter of the edge port of the plastic hose 23 matches the inner diameter of the port of the metal tube 24, and is fixed by plugging when connected. Further, by sleeved on the outer layer of the plugged part, a layer of heat shrink tube 3 is respectively sleeved on the plastic hose 23 and the metal tube 24 on both sides of the connection through its variable diameter structure, so that relative fixation is achieved, and the connection between the plastic hose 23 and the metal tube 24 is prevented from slipping due to external factors such as shaking during operation, so as to protect the internally packaged lead-out optical fiber 22 and prevent it from being damaged by bending.

[0043] Optionally, the lead-out optical fiber 22 passing through the metal tube 24 is fixedly connected to the inner wall of the metal tube 24 by filling epoxy resin a. Exemplarily, in the embodiment of the present invention, one end of the lead-out optical fiber 22 passing through the metal tube 24 extends into the metal tube 24 from the opening of the plastic hose 23, and the other end is fixedly packaged by filling epoxy resin a at the position where it extends out of the metal tube 24, so as to realize the suspended packaging of the lead-out optical fiber 22 inside the metal tube 24 and avoid damage.

[0044] Optionally, the metal tube 24 is fixed to the live contact 12 by spot welding. For example, in the embodiment of the present invention, the metal tube 24 is fixedly connected to the live contact 12 by spot welding, and the welded spot has no effect on the electrical signal of the live contact 12 when it is working. The connection is fastened and stable, ensuring the mechanical protection and accurate measurement of the internal fiber grating 21 and the lead-out optical fiber 22 in a high stress and high temperature environment, and ensuring the reliability and long-term use of the probe.

[0045] Optionally, the live contact 12 is detachably connected to the guide rod 11. For example, in the embodiment of the present invention, the live contact 12 and the metal tube 24 fixed to the live contact 12 are configured to be detachably connected to the guide rod 11, which is convenient for the staff to disassemble for maintenance or replacement after long-term use, thereby improving the overall service life of the optical fiber sensor probe.

[0046] Optionally, the metal tube 24 is a stainless steel tube or a brass tube, and the plastic hose 23 is a polytetrafluoroethylene hose. For example, in an embodiment of the present invention, a circular metal tube 24 made of stainless steel or brass is used to encapsulate the fiber grating 21 and the output optical fiber 22. The inner diameter is 1mm and the wall thickness is 0.5mm. It has excellent mechanical strength and thermal conductivity. While ensuring accurate temperature transfer, the size of the matching structure with the live contact 12 is small enough to facilitate the deployment of the optical fiber sensor probe in a small space. The plastic hose 23 is made of polytetrafluoroethylene, has excellent high temperature resistance, can remain stable at temperatures up to 250°C, and has good corrosion resistance, stability and electrical insulation properties, which can ensure stable insulation packaging protection of the output optical fiber 22 in a high temperature environment.

[0047] Embodiment 2:

[0048] Figure 6 Schematic diagram of a detection device provided by an embodiment of the present invention. Figure 6 As shown, the embodiment of the present invention also provides a detection device, including multiple Figures 1 to 5The optical fiber sensor probe shown also includes a coupler 4, a demodulator 5 and a host computer 6. A plurality of optical fiber sensor probes are arranged in an array, and the lead-out optical fibers 22 of the plurality of optical fiber sensor probes are connected to the demodulator 5 through the coupler 4, and the demodulator 5 is connected to the host computer 6. Exemplarily, the optical fiber sensor probe provided in the embodiment of the present invention is used to form a detection device, which is provided with a metal tube 24 with a built-in optical fiber Bragg grating 21 on a conventional live contact 12 used for docking with a primary terminal of a current transformer m, and the lead-out optical fibers 22 passing through the plurality of metal tubes 24 are packaged and led out through a plastic hose 23 so that the lead-out optical fibers 22 can be docked with an external detection device. When the live contact 12 is used to perform live detection on the output signal of the current transformer m, the fiber grating 21 is used to sense the temperature change at the live contact 12, and the optical signal is transmitted to the external detection equipment using the lead-out optical fiber 22 to sense and detect the working temperature of the live contact 12. The optical fiber material is used as an electrical insulator and does not conduct electricity. The performance of the transmitted optical signal will not be affected in a harsh electromagnetic environment. This ensures accurate temperature perception and detection when the object being measured is live and in areas with complex electromagnetic environments, thereby ensuring safe operation of the calibration process of the current transformer m.

[0049] Furthermore, in the embodiment of the present invention, multiple optical fiber sensor probes are arranged horizontally in this manner, which can ensure that the temperature of multiple points can be sensed simultaneously when the object to be measured is energized, thereby improving the calibration efficiency.

[0050] Embodiment 3:

[0051] Figure 7 FIG. 1 is a flow chart of a detection method provided by an embodiment of the present invention. Figure 7 As shown, the embodiment of the present invention also provides a detection method based on Figure 6 The detection device shown is implemented, comprising the following steps:

[0052] S1. Install the current transformer m to be tested under a plurality of optical fiber sensor probes.

[0053] S2. Adjust the height of the guide rod 11 and the live contact 12 on the base 1 so that the live contact 12 is connected to the primary side terminal at the top of the current transformer m.

[0054] S3. While the current transformer m is working, the fiber grating 21 is used to change the refractive index corresponding to the temperature change at the live contact 12, and the optical signal is transmitted from the lead-out optical fiber 22 to the host computer 6 through the coupler 4 and the demodulator 5 to detect and display the temperature.

[0055] Exemplarily, the detection device provided in the embodiment of the present invention is used, and the above detection method is used to obtain the temperature information of the position of the live contact 12 working under power when the current transformer m is working. The metal tube 24 with the built-in optical fiber grating 21 is set on the live contact 12 conventionally used for docking with the primary terminal of the current transformer m, and the lead-out optical fiber 22 passing through the multiple metal tubes 24 is packaged and led out through the plastic hose 23 so that the lead-out optical fiber 22 can be docked with the external detection equipment. When the live contact 12 is used to detect the output signal of the current transformer m under power, the optical fiber grating 21 is used to sense the temperature change at the live contact 12, and the optical signal is transmitted to the external detection equipment by the lead-out optical fiber 22 to sense and detect the working temperature of the live contact 12. The optical fiber material is used as an electrical insulator and will not conduct electricity. The characteristics that the performance of the transmitted optical signal will not be affected in a harsh electromagnetic environment can ensure that when the object to be measured is charged, the temperature can be accurately sensed and detected in the area with complex electromagnetic environment. While achieving simultaneous multi-point calibration and improving the calibration efficiency, the calibration process of the current transformer m is ensured to operate safely.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit its protection scope. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that after reading the present invention, those skilled in the art can still make various changes, modifications or equivalent substitutions to the specific implementation methods of the invention, but these changes, modifications or equivalent substitutions are all within the protection scope of the pending claims of the invention.

Claims

1. A fiber optic sensor probe, characterized in that: include: Base (1) and temperature sensing component (2), The base (1) is provided with a plurality of guide rods (11) arranged in parallel and at intervals, and the ends of the guide rods (11) are provided with electric contacts (12); The temperature sensing component (2) comprises a fiber grating (21), an output optical fiber (22), a plastic hose (23), and a plurality of metal tubes (24). The plurality of metal tubes (24) are connected one by one to the electric contacts (12) at the ends of the plurality of guide rods (11). The plurality of metal tubes (24) are connected to each other via the plastic hose (23). The other end of one of the metal tubes (24) is connected to the base (1) via the plastic hose (23). The output optical fiber (22) is inserted into the plastic hose (23) and the plurality of metal tubes (24). The fiber grating (21) is arranged on the output optical fiber (22) in the metal tube (24).

2. The optical fiber sensing probe according to claim 1, characterized in that: The guide rod (11) is telescopically connected to the base (1).

3. The optical fiber sensing probe according to claim 2, characterized in that: The plastic hose (23) located between the metal tube (24) and the base (1) is spirally wound around the outer rings of the plurality of guide rods (11).

4. The optical fiber sensing probe according to claim 1, characterized in that: It also comprises a heat shrink tube (3), the end of the plastic hose (23) is inserted into the end opening of the metal tube (24), and the heat shrink tube (3) is fixedly sleeved on the outer wall of the connection between the plastic hose (23) and the metal tube (24).

5. The optical fiber sensing probe according to claim 1, characterized in that: The lead-out optical fiber (22) inserted into the metal tube (24) is fixedly connected to the inner wall of the metal tube (24) by filling epoxy resin (a).

6. The optical fiber sensing probe according to any one of claims 1 to 5, characterized in that: The metal tube (24) and the live contact (12) are fixed by spot welding.

7. The optical fiber sensing probe according to any one of claims 1 to 5, characterized in that: The live contact (12) is detachably connected to the guide rod (11).

8. The optical fiber sensing probe according to any one of claims 1 to 5, characterized in that: The metal tube (24) is a stainless steel tube or a brass tube.

9. The optical fiber sensing probe according to any one of claims 1 to 5, characterized in that: The plastic hose (23) is a polytetrafluoroethylene hose.

10. A detection device, comprising a plurality of optical fiber sensing probes according to any one of claims 1 to 5, characterized in that: It also includes a coupler (4), a demodulator (5) and a host computer (6); a plurality of the optical fiber sensing probes are arranged in an array; the lead-out optical fibers (22) of the plurality of the optical fiber sensing probes are connected to the demodulator (5) via the coupler (4); and the demodulator (5) is connected to the host computer (6).

11. A detection method, implemented based on the detection device according to claim 10, characterized in that: include: The current transformer (m) to be tested is installed below the plurality of optical fiber sensing probes; Adjusting the height of the guide rod (11) and the live contact (12) on the base (1) so that the live contact (12) is butted against the primary side terminal at the top of the current transformer (m); While the current transformer (m) is operating, the fiber grating (21) is used to change the wavelength of the reflected light corresponding to the temperature change at the energized contact (12), and the optical signal is transmitted to the host computer (6) through the coupler (4) and the demodulator (5) by the lead-out optical fiber (22) to detect and display the temperature.

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