Temperature measuring assembly for cable joint of ring main unit and preparation method of temperature measuring assembly

Abstract

The invention discloses a temperature measurement assembly for a ring main unit cable joint and a preparation method, and the temperature measurement assembly comprises a reinforcement member which extends along a first direction, the reinforcement member is provided with a first end and a second end which are opposite in the first direction, and the interior of the reinforcement member is provided with a first hole channel which penetrates through the first end and the second end; one end of the ceramic ferrule is arranged in the first hole channel, the other end of the ceramic ferrule extends out of the first end of the reinforcing piece in the first direction, a second hole channel is formed in the ceramic ferrule, and the first hole channel is communicated with the second hole channel; the ceramic end cap is internally provided with a cavity with one end open and the other end sealed, the end, with the opening, of the ceramic end cap is arranged on the periphery of the ceramic ferrule in a sleeving mode and fixed in the first hole channel, and a fluorescent substance is arranged in the cavity, close to the sealed end, of the ceramic end cap; the optical fiber sheath is connected with the second end of the reinforcing piece, a third hole channel is formed in the optical fiber sheath, and the third hole channel is communicated with the first hole channel; a fastener and an optical fiber. The assembly is simple in installation process and can accurately measure the temperature.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of sensors, and particularly relates to a temperature measuring assembly for a cable joint of a ring main unit and a preparation method. BACKGROUND

[0002] The cable joint of the ring main unit (which can be referred to as a cable joint) is an important component of the ring main unit, which is used to connect the cable to realize the transmission and distribution of power. The ring main unit is a kind of high-voltage switchgear, which is usually used in ring network power supply systems. They can be installed outdoors or indoors, and have different structures and designs to adapt to different application requirements.

[0003] Temperature monitoring of the cable joint is very important for the ring network power supply system. Because the temperature rise of the cable joint can cause problems such as overheating of the cable, insulation aging, etc., which can cause safety accidents or system failures. The traditional infrared temperature detector detects the temperature of the cable joint by installing an optical fiber temperature sensor on the outside of the cable joint. Since it does not directly contact the actual heat point of the internal metal conductor of the cable joint, the temperature measurement accuracy of this method is very low.

[0004] In summary, there is an urgent need to provide a temperature measuring assembly for a cable joint of a ring main unit and a preparation method, which has a simple structure, is easy to install, and is conducive to improving the temperature measurement accuracy. SUMMARY

[0005] The purpose of the embodiments of the present application is to provide a temperature measuring assembly for a cable joint of a ring main unit and a preparation method, which has a simple structure, is easy to install, and is conducive to improving the detection accuracy.

[0006] The embodiments of the present application provide a temperature measuring assembly for a cable joint of a ring main unit and a preparation method. The temperature measuring assembly for the cable joint of the ring main unit comprises: A reinforcing member extending in a first direction, the reinforcing member having opposite first and second ends in the first direction, and an internal first hole passing through the first and second ends; A ceramic plug, one end of which is arranged in the first hole, and the other end extends out of the first end of the reinforcing member in the first direction, the ceramic plug has an internal second hole, and the first hole and the second hole are in communication; A ceramic end cap, which has an internal chamber with one open end and the other sealed end, the ceramic end cap has one end of the open end sleeved on the outer periphery of the ceramic plug, and is fixed in the first hole, and the chamber of the ceramic end cap near the sealed end is provided with a fluorescent substance; An optical fiber sheath connected with the second end of the reinforcing member, and the optical fiber sheath has an internal third hole, and the third hole and the first hole are in communication; A fastener movably sleeved outside the optical fiber jacket for fixing the temperature measuring assembly; An optical fiber, one end of which is arranged in the hole of the ceramic ferrule and in contact with the fluorescent substance, and the other end extends inside the first hole and the third hole.

[0007] According to an embodiment of the present application, the temperature measuring assembly for cable joint of ring main unit further comprises: A heat shrink tube, which is wrapped around the outer periphery of the optical fiber jacket and the reinforcing member to connect the optical fiber jacket and the reinforcing member.

[0008] According to an embodiment of the present application, the temperature measuring assembly for cable joint of ring main unit further comprises: A ceramic sleeve, which is recessed inward from one end to form a receiving cavity, the ceramic end cap, the ceramic ferrule and the reinforcing member are arranged in the receiving cavity, and the sealing end of the ceramic end cap faces the closed end of the ceramic sleeve.

[0009] According to an embodiment of the present application, the fastener comprises: A limiting flange for clamping in the port of the ceramic sleeve; A threaded rod connected with the limiting flange for threaded connection with the side wall of the receiving cavity of the ceramic sleeve.

[0010] According to an embodiment of the present application, the outer periphery of the second end of the reinforcing member is provided with a boss for abutting against the threaded rod when the threaded rod is screwed into the interior of the ceramic sleeve.

[0011] According to an embodiment of the present application, the temperature measuring assembly for cable joint of ring main unit further comprises an insulating plug for connecting with the cable joint, The closed end of the ceramic sleeve extends into the interior of the insulating plug, the open end extends out of the exterior of the insulating plug, and the closed end of the ceramic sleeve abuts against the cable joint.

[0012] According to an embodiment of the present application, the outer periphery of the ceramic sleeve is provided with an inwardly recessed groove, which matches the protrusion inside the insulating plug.

[0013] According to an embodiment of the present application, the ceramic sleeve and the insulating plug are integrally cast to form the ceramic sleeve.

[0014] In a second aspect, the present application further discloses a preparation method of a temperature measuring assembly, which is applied to the temperature measuring assembly for cable joint of ring main unit of the first aspect embodiment, and the preparation method comprises: The first end of the reinforcing member is fixed with the ceramic ferrule by glue, and the optical fiber jacket is connected at the second end of the reinforcing member. sleeve of the optical fiber; inserting the inside of the ceramic ferrule into the optical fiber; applying a fluorescent substance to one end of the ceramic ferrule, and placing the ceramic end cap on the ceramic ferrule and bonding it to the inner wall of the first hole of the reinforcing member.

[0015] As an embodiment of the second aspect, the method further comprises screwing the fastener with the ceramic sleeve.

[0016] The device of the embodiment of the present application has at least the following effects: 1. The temperature measurement assembly for the cable joint of the ring main unit according to the embodiment of the present application is integrated, and can be assembled by screwing the fastener with the ceramic sleeve pre-buried in the insulating plug, so that the installation process is simple.

[0017] 2. The fastener is rotatably sleeved outside the optical fiber sleeve, that is, the temperature measurement probe is separated, and will not be wound around the optical fiber when tightly matched with the ceramic sleeve of the pre-buried member, thereby avoiding the problems of temperature measurement failure and low accuracy, and being conducive to improving the accuracy of temperature detection.

[0018] 3. The insulating plug does not pre-bury the optical fiber, and the temperature measurement assembly does not contain an optical connector, so that additional insertion loss and return loss are not introduced.

[0019] 4. The packaging structure of the temperature measurement assembly of the embodiment of the present application can better protect the optical fiber, and the fluorescent substance is excited and radiated to generate fluorescent light with a wavelength of about high wavelength. After the fluorescent light is transmitted through the optical fiber, it is emitted at the other end of the optical fiber, and the light focused by the lens is captured by the photodetector. The captured light is analyzed to determine the relationship between the fluorescent curve characteristics and the temperature, thereby realizing high-precision temperature detection. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 FIG. 1 is a structural schematic diagram of a temperature measurement assembly for a cable joint of a ring main unit according to an embodiment of the present application.

[0021] Figure 2 FIG. 2 is a cross-sectional structural schematic diagram of the temperature measurement assembly for the cable joint of the ring main unit according to the embodiment of the present application. Figure 3 FIG. 3 is a structural schematic diagram of a temperature measurement assembly for a cable joint of a ring main unit according to another embodiment of the present application. Figure 4 FIG. 4 is a cross-sectional structural schematic diagram of the temperature measurement assembly for the cable joint of the ring main unit according to the another embodiment of the present application. Figure 5 FIG. 5 is a structural schematic diagram of an insulating plug and a ceramic sleeve combined according to another embodiment of the present application. DRAWINGS

[0022] A temperature measuring assembly 100 for cable joints of ring main units; Reinforcing member 10; boss 11; Ceramic ferrule 20; Ceramic end cap 30; Optical fiber sheath 40; Fastener 50; limiting flange 51; threaded rod 52; Optical fiber 60; Heat shrink tube 70; Ceramic sleeve 80; accommodating cavity 81; groove 82; Insulating plug 90; metal nut 91. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0024] The cable joint of the ring main unit (which can be referred to as the cable joint) is an important component in the ring main unit, which is used to connect the cable to realize the transmission and distribution of electric power. The ring main unit is a kind of high-voltage switchgear, which is usually used in ring network power supply system. They can be installed outdoors or indoors, and have different structures and designs to adapt to different application requirements.

[0025] Temperature monitoring of the cable joint is very important for the ring network power supply system. Because the temperature rise of the cable joint can cause problems such as overheating of the cable, aging of the insulation, etc., which can cause safety accidents or system failures. The traditional infrared temperature detector detects the temperature of the cable joint by installing an optical fiber temperature sensor on the outside of the cable joint. Since it does not directly contact the actual heat point of the internal metal conductor of the cable joint, the temperature measurement accuracy of this method is very low.

[0026] In view of the above situation, the embodiments of the present application provide a temperature measuring assembly for cable joints of ring main units and a preparation method. The specific structure and working principle of the temperature measuring assembly 100 for cable joints of ring main units in the embodiments of the present application will be described below in conjunction with the drawings.

[0027] Reference Figure 1 , Figure 1 The structure schematic diagram of the temperature measuring assembly 100 for cable joints of ring main units in the embodiments of the present application is exemplarily shown; Figure 2 The cross-sectional structure schematic diagram of the temperature measuring assembly 100 for cable joints of ring main units in the embodiments of the present application is shown.

[0028] The first direction in this embodiment of the invention is used to indicate the extension direction of the optical fiber 60.

[0029] like Figure 1 The temperature measuring component 100 for the cable connector of the ring main unit includes a reinforcing member 10, a ceramic ferrule 20, a ceramic end cap 30, an optical fiber sheath 40, a fastener 50, and an optical fiber 60. This part of the structure can also be called a temperature measuring probe.

[0030] Specifically, the reinforcing member 10 extends along a first direction, and its interior has a first channel penetrating both ends. One end of the ceramic insert 20 is disposed within the first channel, and the other end extends below the reinforcing member 10 (e.g., Figure 1 Below the reinforcing member 10 shown, the ceramic ferrule 20 has a second channel inside, and the first channel communicates with the second channel. The ceramic end cap 30 has a cavity inside that is open at one end and sealed at the other. The open end of the ceramic end cap 30 is fitted around the outer periphery of the ceramic ferrule 20 and fixed inside the first channel. Fluorescent material is placed in the cavity of the sealed end of the ceramic end cap 30. The optical fiber sheath 40 is connected to the second end of the reinforcing member 10, and the optical fiber sheath 40 has a third channel inside, which communicates with the first channel. The fastener 50 is movably fitted outside the optical fiber sheath 40 for fixing to the temperature sensing assembly 100. One end of the optical fiber 60 is disposed inside the channel of the ceramic ferrule 20 and in contact with the fluorescent material, and the other end extends along the inside of the first and third channels. The optical fiber 60 can be an ultraviolet optical fiber for transmitting ultraviolet light and fluorescence signals. It should be noted that the fastener 50 fixing the temperature sensing assembly refers to fixing the temperature sensing probe.

[0031] The working principle of the temperature measuring component 100 for the cable connector of the ring main unit in this embodiment of the invention is as follows: the LED in the fluorescent fiber optic temperature demodulator emits detection light, which is reflected by the filter in the fluorescent fiber optic temperature demodulator and then focused by a biconvex lens. The end face of the optical fiber 60 (which can be an ultraviolet fiber) is placed at the focusing point of the biconvex lens. After the detection light is coupled into the optical fiber 60, it excites the fluorescent material located at the other end of the optical fiber 60. The fluorescent material emits fluorescence with a wavelength of approximately a high wavelength after stimulated emission. The fluorescence is transmitted through the optical fiber 60 and emitted at the other end of the optical fiber 60. The light, after being focused by the lens, is captured by the photodetector in the fluorescent fiber optic temperature demodulator. By analyzing the relationship between the fluorescence curve characteristics and the temperature, high-precision temperature detection is achieved.

[0032] The demodulation optical path works by utilizing the fact that the non-radiative transition efficiency of the encapsulation material used in the fluorescent probe is temperature-dependent, and the non-radiative transition efficiency can be measured by the quenching time. This means that temperature can be detected by measuring the fluorescence quenching time, and the fluorescence quenching curve detected by the diode can be fitted as follows:

[0033] wherein is the fluorescent signal received by the photodetector, is the intensity of the fluorescent signal, is time, is the fluorescence quenching time, is the direct current component. The area S can be expressed as: Let: The direct current component can be removed: Therefore, the fluorescence quenching time can be expressed as:

[0034] This algorithm can efficiently calculate the fluorescence quenching time of the fluorescent substance in the probe, and the measured temperature can be obtained by fitting with the temperature to a first or second order univariate function. This way of testing the temperature is more accurate and reliable.

[0035] In the embodiment of the present application, the temperature measuring probe forms an integral whole, and can be assembled by tightening the movable threaded male head (fastener 50) of the probe with the threaded female head (ceramic sleeve 80) of the ceramic tube embedded in the insulating plug 90. The installation process is simple, convenient and not easy to damage the probe. Moreover, the movable threaded male head is externally movable from the optical fiber sheath 40, and the rotation of the movable threaded male head will not cause the rotation and twisting of the optical fiber sheath 40 and the optical fiber 60. This way will not cause the temperature measurement to fail or be inaccurate due to damage to the optical fiber 60 during the installation of the optical fiber probe, which is conducive to the accuracy of temperature measurement. In addition, the temperature measuring probe does not contain an optical connector, and the optical fiber 60 is a complete whole, and there is no segmented optical fiber embedded in the insulating plug 90, so there is no need to connect the optical fibers through the optical connector, and therefore no additional insertion loss and return loss is introduced.

[0036] In the embodiment of the present application, the material of the optical fiber sheath 40 can be fluorinated ethylene propylene (FEP), or other high-temperature resistant materials, which has a long-term working temperature of -40-150℃, which can meet the working environment temperature requirements of the cable joint. The optical fiber sheath 40 is connected to the reinforcing member 10 through the FEP heat shrink tube 70, which improves the stability and high-temperature resistance of the connection.

[0037] In the embodiment of the present application, as Figure 2 and 3As shown, the inner diameter of the active threaded male head (fastener 50) is slightly larger than the outer diameter of the optical fiber jacket 40 and slightly smaller than the outer diameter of the reinforcing member 10. Since the active threaded male head is separated from the optical fiber jacket 40 and the reinforcing member 10 of the temperature measurement probe, it will not rotate and twist the optical fiber 60 during the screwing process with the ceramic sleeve 80, and thus will not damage the optical fiber 60.

[0038] In some embodiments, the optical fiber channel (first channel) of the reinforcing member 10 can communicate the optical sensing signal. As shown Figure 2 As shown, the reinforcing member 10 can also be provided with a grinding fixed groove, which is used in cooperation with the grinding disc when grinding the end face of the optical fiber 60. The channel opened in the reinforcing member 10 can be inserted into the ceramic ferrule 20 and used to fix the ceramic ferrule 20. The bottom of the opened channel can be provided with a glue storage for storing excess glue, facilitating the stable connection of the ceramic ferrule 20.

[0039] As shown Figure 2 As shown, the ring main unit cable joint temperature measurement assembly 100 further comprises a heat shrink tube 70, which is wrapped around the outer periphery of the optical fiber jacket 40 and the reinforcing member 10 to connect the optical fiber jacket 40 and the reinforcing member 10.

[0040] Referring to Figures 3-5 , the ring main unit cable joint temperature measurement assembly 100 further comprises a ceramic sleeve 80, which is recessed inward from one end to form a containing cavity 81, and the ceramic end cap 30, the ceramic ferrule 20 and the reinforcing member 10 are placed in the containing cavity 81, and the sealing end of the ceramic end cap 30 contacts the closed end of the ceramic sleeve 80. That is, on the one hand, the ceramic sleeve 80 can better protect the temperature measurement probe; on the other hand, the ceramic sleeve 80 can be pre-embedded in the set component, for example, pre-embedded in the insulating plug 90. The ceramic sleeve 80 not only has the function of insulation, but also has the function of good heat conduction. Then the bottom of the ceramic sleeve 80 directly contacts the metal conductor in the insulating plug 90, which can be a metal nut screwed with the cable joint, thereby realizing rapid heat conduction and effectively ensuring the accuracy of temperature measurement. The metal nut is in the shape of a cap with a threaded hole at one end and a closed end at the other end, and the threaded hole is directed towards the outside of the insulating plug 90.

[0041] Further, the outer surface of the bottom of the ceramic sleeve 80 is in contact with the surface of the metal conductor in the insulating plug 90, which realizes rapid heat conduction through surface contact, so that the temperature of the ceramic sleeve 80 quickly converges to the temperature of the metal conductor in the insulating plug 90, thereby realizing rapid and accurate temperature detection.

[0042] Furthermore, the ceramic sleeve 80, ceramic insert 20, and ceramic end cap 30 actually form a heat-conducting channel for rapid heat conduction to the fluorescent material within the insulating and heat-insulating body of the insulating plug 90, which has insulation and heat insulation properties. On the one hand, the closer the fluorescent material is to the metal conductor in the first direction, the larger the heat-conducting channel formed by the ceramic sleeve 80, ceramic insert 20, and ceramic end cap 30 in conjunction with the metal conductor, the easier it is to make the measured temperature more accurate and the faster the temperature change feedback speed. However, the thinner the wall of the ceramic sleeve 80, the more easily it is damaged under stress. Therefore, it is necessary to balance thermal conductivity and structural reliability, requiring specific design. In some embodiments, the distance between the fluorescent material and the metal conductor in the first direction is A, where 1 ≤ A ≤ 5 mm. Simultaneously, the bottom end face of the ceramic sleeve 80 is a circular plane, and the corresponding end face of the metal conductor in the insulating plug 90 is also a plane. The bottom end face of the ceramic sleeve 80 is in contact with the corresponding end face of the metal conductor, and the area of ​​the bottom end face of the ceramic sleeve 80 exceeds 50% of the area of ​​the corresponding end face of the metal conductor, preferably exceeding 80%, thereby enabling faster and more efficient surface contact heat conduction. By simultaneously meeting the above requirements, both thermal conductivity and structural reliability can be achieved.

[0043] In some embodiments, the ceramic sleeve 80 is an alumina ceramic sleeve. Compared with the epoxy resin material of the insulating plug 90, alumina ceramic has a great advantage in thermal conductivity and high temperature resistance. Therefore, the alumina ceramic tube is selected as the mounting carrier of the temperature probe.

[0044] In some embodiments, the ceramic sleeve 80 may also be a gasket structure, but this application does not limit it to only one type.

[0045] like Figure 4 As shown, the fastener 50 includes a limiting flange 51 and a threaded rod 52. The threaded rod 52 is connected to the limiting flange 51 to form a T-shape. During installation, the threaded rod 52 can be threadedly fastened to the ceramic sleeve 80. During the fastening process, the limiting flange 51 can limit the fastener 50 to the port of the ceramic sleeve 80, thereby limiting the depth of the fastener 50 screwing in. This ensures that the sealing end of the ceramic end cap 30 just contacts the closed end of the ceramic sleeve 80, which guarantees good heat conduction and better protects the internal structure of the temperature probe. Preferably, the sealing end of the ceramic end cap 30 has an end face that fits against the closed end of the ceramic sleeve 80. Compared with point contact, end face contact can better achieve heat transfer and disperse stress, avoiding stress concentration that could lead to damage.

[0046] Furthermore, the portion of the ceramic end cap 30 extending out of the reinforcing member 10 is tightly fitted to the inner wall of the ceramic sleeve 80, thereby maximizing the heat conduction area and further improving the heat conduction efficiency, thus making temperature monitoring faster and more accurate.

[0047] As shown in Figure 4 , the outer periphery of the second end of the reinforcing member 10 is provided with a boss 11, which can abut against the bottom of the threaded rod 52 when the threaded rod 52 is screwed into the inside of the ceramic sleeve 80, thereby further limiting the screwing depth of the fastener 50.

[0048] As shown in Figures 3-5 , the temperature measurement assembly 100 for the cable joint of the ring main unit further comprises an insulating plug 90. The closed end of the ceramic sleeve 80 extends into the inside of the insulating plug 90, the open end extends out of the outside of the insulating plug 90, and the closed end of the ceramic sleeve 80 abuts against the metal nut 91. Among them, 80 is located on the central axis of the metal nut 91. Thus, after the fastener 50 of the temperature measurement probe and the ceramic sleeve 80 are fixed, the temperature measurement probe is fixed, so that the temperature measurement probe realizes stable contact with the heating point of the cable joint through the ceramic sleeve 80 and the metal nut 91, which is beneficial to ensure the accuracy of temperature measurement.

[0049] As shown in Figure 5 , the outer periphery of the ceramic sleeve 80 is provided with an inwardly recessed groove 82, which is matched with the protrusion in the insulating plug 90, and the transverse section is square-shaped, preventing the ceramic sleeve 80 from moving radially in the insulating plug 90. The ceramic sleeve 80 and the insulating plug 90 are casted and formed, making the overall connection more firm. Specifically, the groove 82 can be an annular groove around the outer periphery of the ceramic sleeve 80, so that the protrusion in the insulating plug 90 can fill the annular groove and prevent the ceramic sleeve 80 from moving radially in the insulating plug 90. Further, the groove 82 can be an open-loop strip-shaped groove extending along the circumference of the ceramic sleeve 80, which can also limit the rotation of the ceramic sleeve 80 in the insulating plug 90.

[0050] The preparation method of the temperature measurement assembly 100 of the embodiment of the present application will be described below in combination with the embodiment of the present application. Figures 1-5

[0051] The preparation method of the temperature measurement assembly 100 of the embodiment of the present application mainly includes two parts, one is the insulating material plug (consisting of the insulating plug 90, the metal nut 91 and the ceramic sleeve 80), and the other is the temperature measurement probe (including the reinforcing member 10, the ceramic ferrule 20, the ceramic end cap 30, the optical fiber sheath 40, the fastener 50 and the optical fiber 60, and the fluorescent substance).

[0052] First, the preparation of the insulating material plug is described.

[0053] ​Step 11, insulation material preparation, generally uses epoxy resin, because epoxy resin has good chemical resistance, corrosion resistance and electrical insulation. The curing agent is a substance that cures the epoxy resin, and the commonly used curing agent includes amine, acid anhydride and the like. The filler can improve the strength, rigidity and wear resistance of the epoxy injection molding part; Step 12, model the insulation plug, the mold is made of tool steel, which has good wear resistance and heat resistance. In addition, the mold needs to ensure that it meets the size design requirements and has a smooth surface without defects. Step 13, mix the raw materials such as epoxy resin and curing agent in proportion to obtain epoxy injection molding material. Step 14, inject the epoxy injection molding material into the mold containing the cable joint and the ceramic sleeve 80, and keep it at a certain temperature and pressure for a certain time, so that the epoxy injection molding material and the metal nut and the ceramic sleeve 80 are cured and formed. Generally, the higher the curing temperature, the shorter the curing time. Preferably, the curing temperature is 100°C, the curing time is 30 minutes, and the pressure is 50 psi, which is used to remove the bubbles generated during the curing process. Finally, the insulation material plug is obtained. Specifically, the mold includes an upper mold body and a lower mold body that cover each other. The upper mold body is provided with a first assembly cavity for the ceramic sleeve 80, and the ceramic sleeve 80 is assembled in the first assembly cavity. The lower mold body is provided with a second assembly cavity for fixing the metal nut, and the metal nut is assembled in the second assembly cavity. Then, the upper mold body and the lower mold body are closed together to cooperate with the ceramic sleeve 80 and the metal nut assembled therein to enclose a cavity for forming an insulation body of the insulation plug 90. Then, the insulation plug 90, i.e. the insulation material plug, is prepared by the casting process.

[0054] Secondly, the preparation of the temperature measuring probe is described.

[0055] Step 21, fix the first end of the reinforcing member 10 and the ceramic ferrule 20 with glue, for example, epoxy glue. And connect the optical fiber jacket 40 to the second end of the reinforcing member 10. The optical fiber jacket 40 can be made of FEP material.

[0056] Step 22, put the fastener 50 on the outer periphery of the optical fiber jacket 40.

[0057] Step 23, pass the optical fiber 60 into the inside of the ceramic ferrule 20. The core diameter of the optical fiber 60 is 200-400 microns. The high-temperature resistant coating layer includes but is not limited to polyimide, PFA, hard plastic, etc.

[0058] Step 24, apply fluorescent substance to one end of the ceramic ferrule 20, or add fluorescent substance in the ceramic end cap 30, and place the ceramic end cap 30 on the ceramic ferrule 20 and bond with the inner wall of the first hole of the reinforcing member 10. The fluorescent substance includes but is not limited to magnesium fluorogermanate, potassium fluorosilicate, barium magnesium silicate, etc.

[0059] Step 25, the fastener 50 is screwed with the ceramic sleeve 80 (with internal thread), that is, the assembly of the temperature measuring plug is completed. The packaging method is simple. When actually measuring the temperature, the insulating plug 90 is first screwed with the T-shaped cable joint through the metal nut inside the insulating plug 90, and then the fastener 50 is screwed with the ceramic sleeve 80 (with internal thread). The temperature measurement is convenient to operate.

[0060] In summary, the temperature measuring assembly for the cable joint of the ring main unit is integrated, and no optical fiber is pre-buried in the insulating plug 90. The assembly can be realized by tightening the fastener 50 of the temperature measuring probe and the ceramic sleeve 80 pre-buried in the insulating plug 90, and the installation process is simple. The fastener 50 is movably sleeved outside the optical fiber sheath 40, that is, the temperature measuring probe is separated, and the fastener 50 will not be wound around the optical fiber 60 when tightly matched with the ceramic sleeve 80 of the pre-buried part, thereby avoiding the problems of temperature measurement failure and low accuracy, and facilitating the improvement of the accuracy of temperature detection. In addition, no optical fiber is pre-buried in the insulating plug 90, so the temperature measuring assembly for the cable joint of the ring main unit does not contain an optical connector, and the two-section split optical fiber does not need to be connected and spliced, so it will not bring in additional insertion loss and return loss. The packaging structure of the temperature measuring assembly for the cable joint of the ring main unit can better protect the optical fiber 60, and the fluorescent substance is excited and radiated to generate fluorescent light with a wavelength of about high wavelength. After the fluorescent light is transmitted through the optical fiber 60, it is emitted at the other end of the optical fiber 60, and the light focused by the lens in the fluorescent temperature demodulator is captured by the photodetector. The captured light is analyzed to determine the relationship between the fluorescent curve characteristics and the temperature, thereby realizing high-precision temperature detection.

[0061] It can be understood that, in the description of the present application, it should be understood that the terms "upper", "lower", "bottom", "top", "front", "back", "inner", "outer", "horizontal", "vertical" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0062] It can be understood that, in the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "coupling", "communication", "connection", "connection", "cooperation" should be understood broadly, for example, it can be fixedly connected, integrally connected, or detachably connected; it can be the communication between the interiors of two elements; it can be directly connected, or indirectly connected through an intermediate medium; "cooperation" can be the cooperation of surfaces, or the cooperation of points and surfaces or lines and surfaces, and also includes the cooperation of holes and shafts. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0063] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other modifications under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these modifications are within the protection scope of the present invention.

Claims

1. A temperature measuring component for a cable connector in a ring main unit, characterized in that, include: A reinforcing member extending along a first direction, the reinforcing member having a first end and a second end opposite to each other in the first direction, and having a first channel passing through the first end and the second end inside; A ceramic insert has one end disposed in the first channel and the other end extending out of the first end of the reinforcing member along the first direction. The ceramic insert has a second channel inside, and the first channel communicates with the second channel. A ceramic end cap has an internal cavity with one end open and the other end sealed. The end of the ceramic end cap with the opening is fitted onto the outer periphery of the ceramic insert and fixed in the first channel. A fluorescent material is provided in the cavity of the ceramic end cap near the sealed end. The optical fiber sheath is connected to the second end of the reinforcing member, and the optical fiber sheath has a third channel inside, which communicates with the first channel; Fasteners, which are rotatably fitted over the fiber optic sheath, are used to fix the temperature measuring component. An optical fiber, one end of which is disposed within the channel of the ceramic ferrule and in contact with the fluorescent material, and the other end extending along the interior of the first channel and the third channel.

2. The temperature measuring component for the cable joint of the ring main unit according to claim 1, characterized in that, Also includes: A heat shrink tubing is wrapped around the outer periphery of the optical fiber sheath and the reinforcing member to connect the optical fiber sheath and the reinforcing member.

3. The temperature measuring component for the cable joint of the ring main unit according to claim 2, characterized in that, Also includes: A ceramic sleeve, wherein the ceramic sleeve is recessed inward from one end to form a receiving cavity, the ceramic end cap, the ceramic insert and the reinforcing member are placed in the receiving cavity, and the sealing end of the ceramic end cap contacts the closed end of the ceramic sleeve.

4. The temperature measuring component for the cable joint of the ring main unit according to claim 3, characterized in that, The fasteners include: A limiting flange, which is used to snap onto the port of the ceramic sleeve; A threaded rod, connected to the limiting flange, is used for threaded connection with the side wall of the receiving cavity of the ceramic sleeve.

5. The temperature measuring component for the cable joint of the ring main unit according to claim 4, characterized in that, The second end of the reinforcing member has a boss on its outer periphery, which is used to abut against the threaded rod when the threaded rod is screwed into the ceramic sleeve.

6. The temperature measuring component for the cable joint of the ring main unit according to claim 3, characterized in that, It also includes an insulating plug for connection to the cable connector. The closed end of the ceramic sleeve extends into the interior of the insulating plug, the open end extends out of the outside of the insulating plug, and the closed end of the ceramic sleeve abuts against the metal nut of the cable connector.

7. The temperature measuring component for the cable joint of the ring main unit according to claim 6, characterized in that, The outer periphery of the ceramic sleeve is provided with an inwardly recessed groove, which matches the protrusion inside the insulating plug.

8. The temperature measuring component for the cable joint of the ring main unit according to claim 7, characterized in that, The ceramic sleeve and the insulating plug are cast together.

9. A method for preparing a temperature measuring component, applied to the temperature measuring component for a ring main unit cable joint as described in any one of claims 1-8, characterized in that, include: The first end of the reinforcing member is fixed to the ceramic ferrule with glue, and the optical fiber sheath is connected to the second end of the reinforcing member. The fastener is fitted onto the outer periphery of the optical fiber sheath; The optical fiber is inserted into the interior of the ceramic ferrule; A fluorescent material is applied to one end of the ceramic insert, and a ceramic end cap is placed on the ceramic insert and bonded to the inner wall of the first channel of the reinforcing member.

10. The method for preparing the temperature measuring component according to claim 9, characterized in that, The method, which is applied to the temperature measuring component for the cable connector of the ring main unit as described in claim 3, further includes threading the fastener to the ceramic sleeve.

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