CN117537949A - Temperature measurement sensing device and cable joint mounting structure - Google Patents

Abstract

The invention relates to the technical field of high-voltage cable temperature measurement, and discloses a temperature measurement sensing device and a cable connector mounting structure. The temperature measuring sensing device disclosed by the invention can solve the problem of wireless temperature monitoring inside the cable plug of the ring main unit.

Description

A temperature sensing device and cable joint installation structure

Technical field

The invention relates to the technical field of high-voltage cable temperature measurement, and in particular to a temperature measurement sensing device and a cable joint installation structure.

Background technique

Ring main unit is a special electrical connection device widely used in AC 10KV power distribution systems such as industrial and mining enterprises, residential areas, ports and high-rise buildings to complete the collection and classification functions of cable lines and has control and measurement functions. The plug is the main component of the high-voltage cable connection in the high-voltage ring main unit, which plays the roles of connection, insulation, shielding, and protection. In actual applications, there is contact resistance at the cable connection, which easily accumulates heat, causing the temperature to be too high, leading to accidents such as explosions or fires. Therefore, it is very necessary to monitor the internal temperature of the plug.

Currently, the commonly used methods for temperature measurement in high voltage environments include the following:

1. Wax chip temperature measurement technology:

The advantages are simplicity and low cost. The disadvantage is low accuracy, poor reliability, and inability to achieve real-time monitoring. Moreover, it is impossible to measure parts such as T-shaped cable joints in the ring main unit that are prone to heat and are invisible during operation.

2. Thermal infrared temperature measurement technology:

The advantages are large measurement range, high accuracy and good reliability. The disadvantage is that the equipment is expensive, requires manpower for regular inspections, and cannot achieve real-time monitoring of temperature. And for the hidden position of the cable connector, the infrared thermometer can no longer measure the temperature. In addition, infrared thermometers are greatly interfered by sunlight and generally need to be measured at night or on cloudy and rainy days.

3. Fiber Bragg grating temperature measurement technology:

A grating sheet is used as a temperature sensor and is pasted on the surface of the measured point. The thermometer (spectrum analyzer) and the temperature sensor are connected through an optical fiber. The disadvantage is that the optical fiber is easy to break and is not resistant to high temperatures. After the optical fiber accumulates dust, its insulation performance is reduced in a humid environment, resulting in discharge along the optical fiber surface, which poses a safety hazard. The installation and debugging workload is large and the cost is high.

Now with the development of RFID radio frequency identification technology and the emergence of temperature measurement chips, the combination of the two can realize passive wireless monitoring of temperature at cable joints, and can also avoid secondary accidents. However, since the cable plug has metal parts inside and the electromagnetic environment is poor, existing temperature measurement devices are generally used on the surface of the black rubber protective sheath outside the cable plug, which cannot actually measure the internal temperature of the plug. There are significant deviations in the temperature data, and the practical significance is very low.

Contents of the invention

In order to solve the existing problems in the prior art, such as inaccurate measurement and large influence by environmental factors, when monitoring plug temperature in a high-pressure environment, the present invention designs a temperature measurement sensing device and a cable including the temperature measurement sensing device. The purpose of the joint installation structure is to solve the problem of wireless temperature monitoring inside the cable plug of the ring main unit.

The technical solution adopted by this device is: a temperature measurement sensing device, including a nut, a temperature measurement label and a shell cover. The nut constitutes the main body of the temperature measurement sensing device. There are grooves on the side of the nut. There is a pair of mounting holes on both sides of the groove plane, and the temperature measuring label is placed in the groove. The width of the temperature measuring label is smaller than the distance between the left and right pairs of mounting holes, so that the mounting holes are exposed outside the groove. An outer shell cover is provided, and mounting posts are connected to both sides of the outer shell cover. The outer shell cover is mounted on the groove by inserting the mounting posts into corresponding mounting holes.

Preferably, the temperature measurement tag is composed of a chip, a radiation antenna, and a medium. The chip refers to a passive ultra-high frequency RFID chip with a temperature measurement function. The radiation antenna refers to two terminals connected to the chip RF+ and RF- (GND). The electromagnetic wave energy receiving and reflecting device of the corresponding chip can be matched between the terminals, and the medium includes ceramics, PCB, and high-frequency boards.

Preferably, one or more grooves are provided on the side of the nut, a temperature measurement label is fixed on each groove, and a shell cover is provided on the outside of each groove.

Preferably, the thickness of the nut is 7mm-10mm, the slot width of the nut is 5.5mm-7mm, the width of the temperature measurement label is 4mm-6mm, and the chip in the temperature measurement label is connected to the groove side The distance between the wall and one side is 0mm-1mm.

Preferably, the angle between the main polarization direction of the temperature measurement tag and the normal direction of the nut does not exceed 30 degrees, and the temperature measurement tag is any anti-metal tag with a size of 4 mm or more along the normal direction of the nut.

Preferably, the temperature measurement tag is a ceramic tag with a length*width=5mm*5mm and a dielectric constant between 140 and 180, or a ceramic tag with a length*width=10mm*5mm and a dielectric constant greater than 50.

The application also includes a cable joint installation structure, including the above-disclosed temperature sensing device, a screw, a plug, a metal cup, and a copper nose. The metal cup is embedded inside the plug, and one end of the screw is inserted into Inside the metal cup, the other end extends to the outside of the plug. A copper nose is hung on the end of the screw rod away from the plug. The screw rod is equipped with a temperature sensing device, a spring gasket, an ordinary gasket, and a positioning device. Pads and several other pads.

Preferably, the spring gasket is an unclosed ring, the ordinary gasket is a closed ring structure, and the positioning gasket and other gaskets are hollow thin sheets.

Preferably, the positioning pad is used to control the distance between the metal cup mouth and the surface of the copper nose; the other pads are provided with 1-4, which can be used to control the screw space between the metal cup and the copper nose. The installation position can be set freely; the positioning pad and other pads can be used alone or in any combination, and are used to create an insulating gap between the rim of the metal cup and the surface of the copper nose.

Preferably, by increasing the thickness of the ordinary gasket or spring gasket, the function of any other gasket can be equivalently replaced, and by increasing the outer diameter of the ordinary gasket or spring gasket, the function of the positioning gasket can be equivalently replaced.

Compared with the existing technology, this device has the following beneficial effects: This application uses RFID radio frequency identification technology, combined with the temperature measurement chip, the internal structure and electromagnetic environment of the ring main unit cable head, to provide a plug cup A UHF band temperature measurement RFID sensing device inside the body space. The sensing device has the characteristics of small thickness, strong signal and no potential hazard of partial discharge. At the same time, a cable joint installation structure containing the sensing device is provided. This better solves the problem of wireless temperature monitoring inside the cable plug of the ring main unit. The placement direction of the temperature sensing device in the plug can be chosen arbitrarily, and it will have little impact on its sensitivity. After the installation is completed, the sensitivity margin of the temperature sensing device exceeds 10dBm. Generally speaking, the product is easy to install, easy to debug, has a simple structure, has no impact on the original installation structure of the ring main unit plug, and can realize batch processing, production and application.

Description of drawings

Figure 1 is a structural diagram of a temperature sensing device (single slot structure).

Figure 2 is an installation structural diagram of the temperature sensing device of Figure 1 installed on the plug of the ring main unit.

Figure 3 is another representation of Figure 2.

Among them, 1. Plug; 2. Metal cup; 3. Screw; 4. Copper nose; 5. Temperature measurement sensing device; 51. Nut; 52. Temperature measurement label; 53. Shell cover; 54. Mounting column; 6. Spring gasket; 7. Ordinary gasket; 8. Positioning gasket; 9. Other gaskets.

Detailed ways

Embodiments of the present application will be described in detail below. Throughout this specification, identical or similar components and components having the same or similar functions are designated by similar reference numerals. The embodiments described herein with respect to the accompanying drawings are illustrative and diagrammatic in nature and are intended to provide a basic understanding of the present application. The embodiments of the present application should not be construed as limitations of the present application. In order to make the above objects, features and advantages of the present invention more obvious and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

This application relates to a UHF frequency band temperature measurement RFID sensing device placed inside the cup body space of plug 1. As shown in Figure 1, the main body of the device is a nut 51, and a nut 51 is provided on the side wall of the nut 51. to a plurality of grooves, and a temperature measurement tag 52 is placed in each groove. The temperature measurement tag 52 is composed of a chip, a radiation antenna, and a medium, where the chip refers to a passive ultra-high frequency RFID chip with a temperature measurement function. The radiation antenna refers to the electromagnetic wave energy receiving and reflecting device connected to the chip RF+, RF- (GND) that can match the corresponding chip. The medium generally refers to ceramics, PCB, high-frequency boards, etc. RFID temperature measurement tags combine radio frequency identification (RFID) technology and temperature sensors to monitor and record the temperature of objects in real time. Specifically, the temperature sensor can sense the temperature of objects in real time and transmit the data to the RFID chip. Through wireless communication, the RFID chip transmits temperature data to the reader, and the reader uploads the data to a central server for storage and analysis. Holes are drilled at both ends of each groove, and each groove is equipped with a housing cover 53 with a mounting post 54. The mounting posts 54 are inserted into the holes at both ends of the groove, so that the housing cover 53 can be installed. On the groove, the sealing and fixing effect of the temperature measurement label 52 is completed. In this embodiment, the thickness of the nut 51 as the main body of the temperature measurement sensing device 5 is 7-8mm, the width of the groove opened by the nut 51 is 5.5-7mm, the width of the built-in temperature measurement label 52 is 4-6mm, and the width of the built-in temperature measurement label 52 is 4-6mm. The distance between the temperature label 52 and the groove wall of the nut 51 is 0-1 mm.

Specifically, the number of grooves on the side wall of the nut 51 can be freely adjusted according to actual needs, and each groove is equipped with the same temperature measurement label 52 and is closed with a shell cover 53 . Figure 1 shows a nut structure with a single groove. Generally speaking, the more grooves there are, the more temperature measurement tags 52 are installed, which will improve the temperature measurement performance of the temperature measurement device. However, an increase in the number of grooves will lead to an increase in cost and will also reduce the strength of the nut 51. Therefore, in actual use, it is better to have a single-sided groove or a double-sided groove on the side wall of the nut 51. In this embodiment, the temperature measurement label 52 used is a temperature measurement label with a length*width=5mm*5mm and a dielectric constant between 140 and 180, or a temperature measurement label with a length*width=10mm*5mm and a dielectric constant greater than 50. Temperature tags, or other sensing tags whose size along the normal direction of the nut 51 is greater than or equal to 4 mm.

This application also relates to a cable joint installation structure using the temperature sensing device 5 as described above. As shown in Figure 2-3, it consists of a plug 1, a metal cup 2, a screw 3, a copper nose 4, and a nut. It is composed of sensing device 5, spring pad 6, ordinary pad 7, positioning pad 8 and several other pads 9. The core of the installation structure is to install the nut sensing device into the plug 1 of the ring main unit. First, hang the copper nose 4 on one end of the screw 3 to complete the fixation of the two. Then install ordinary gaskets 7 and 7 from the other end of the screw 3. Spring gasket 6, temperature sensing device 5, plug 1, and then install a certain number of gaskets according to actual needs. Ordinary gasket 7 and spring gasket 6 are fixed structures required to install a fixed temperature measurement device. The other gaskets are any insulating materials with a certain thickness and through holes that have a supporting function. They are mainly used for metal cups 2. Create an insulation gap between the edge and the surface of the copper nose 4. The number and installation position of these gaskets can be set according to actual needs. You can also increase the thickness of ordinary gaskets 7 and spring gaskets 6 to achieve the same value as additional gaskets. role. It should be pointed out that these pads contain a positioning pad 8, which is arranged at the mouth of the metal cup 2 and is used to control the distance between the mouth of the metal cup 2 and the surface of the copper nose 4. The positioning pad The function of 8 can also be equivalently replaced by increasing the diameter of the ordinary gasket 7 and the spring gasket 6.

The metal cup 2 in the ring main unit has an antenna effect. This antenna effect has obvious linear polarization characteristics. It has the most effective reception effect on electromagnetic waves whose polarization direction is parallel to the normal direction of the metal cup 2 and perpendicular to the direction of the electromagnetic wave. The reception effect of electromagnetic waves in the polarization direction is very weak. In addition, when there is a certain insulation gap between the rim part of the metal cup 2 and the surface of the copper nose 4, the antenna effect of the metal cup 2 is significant. When the rim part of the metal cup 2 comes into contact with the surface of the copper nose 4 , the antenna effect of the metal cup 2 is weak. The present invention utilizes the coupling effect of the metal cup 2 itself on electromagnetic waves with a specific polarization direction, and sets the main polarization direction of the built-in temperature measurement tag 52 to be parallel to the normal direction of the nut 51 (in practical applications, the deviation angle is controlled within 30 degrees). ), so that the temperature measurement tag 52 can introduce the electromagnetic wave energy received by the metal cup 2 to the temperature measurement tag 52 through coupling with the metal cup 2 (since the nut 51 is parallel to the placement direction of the metal cup 2, the nut 51 is The normal direction of 51 is the normal direction of the metal cup 2), which makes the signal transmission mode change from: collector antenna → obstacle (metal cup 2) → sensor, to collector antenna → directional coupler ( Metal cup 2) → sensor. The original signal transmission is shielded by obstacles, causing the signal transmitted to the sensor to be relatively weak, which affects the measurement results. After using this temperature measurement device, the signal strength transmitted to the temperature measurement tag 52 can be significantly improved.

On the other hand, existing nut-type sensors on the market generally have a problem of relatively large thickness, and their actual thickness generally reaches more than 12 mm. The increased thickness causes a significant gap between the cup body of the plug 1 and the copper nose 4. The electromagnetic waves enter and exit the space inside the cup through the gap, so that the sensor can communicate with the receiving device. However, the increased thickness of the nut changes the original installation structure of the insulating plug 1, which may cause the protruding length of the screw 3 at the nut end to be too small, making it difficult to tighten the plug 1 or after the plug 1 is tightened, its metal cup 2 and the copper nose The gap of 4 is too large. The temperature measurement sensing device 5 of the present invention has a groove on the side of a nut 51. The groove structure does not affect the integrity of the upper and lower fastening surfaces of the nut 51. A ceramic temperature measurement label 52 can be normally accommodated in the groove. This structure The design significantly reduces the gap width requirement on the surface of the metal cup body 2 and the copper nose 4, thereby reducing the thickness of the nut 51 to less than 8 mm and avoiding the risk of partial discharge caused by an excessive gap.

In general, the present invention combines RFID radio frequency identification technology to solve the problem of wireless monitoring of temperature inside the cable plug 1 of the ring main unit. The temperature sensing device 5 can be installed in any direction in the plug 1, and its sensitivity The impact is not significant. After the overall installation is completed, the sensor sensitivity margin exceeds 10dBm. Generally speaking, the product is easy to install, easy to debug, has a simple structure, has no impact on the original installation structure of the ring main unit plug 1, and can realize batch processing, production and application.

Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be subject to the scope defined by the claims.

The technical content and technical features of the present application have been disclosed as above. However, those skilled in the art may still make various substitutions and modifications based on the teachings and disclosures of the present application without departing from the spirit of the present application. Therefore, the protection scope of the present application should not be limited to the contents disclosed in the embodiments, but should include various substitutions and modifications that do not deviate from the present application, and should be covered by the claims of this patent application.

Claims (10)

1. A temperature measurement sensing device, characterized in that it includes a nut, a temperature measurement label and a housing cover. The nut constitutes the main body of the temperature measurement sensing device. A groove is provided on the side of the nut. The groove is There is a pair of mounting holes on both sides of the plane, and the temperature measuring label is placed in the groove. The width of the temperature measuring label is smaller than the distance between the two pairs of mounting holes on the left and right, so that the mounting holes are exposed. There is a pair of mounting holes on the outside of the groove. The housing cover has mounting posts connected to both sides of the housing cover. The housing cover is installed on the groove by inserting the mounting posts into the corresponding mounting holes. 2. The temperature measurement sensing device according to claim 1, wherein the temperature measurement tag is composed of a chip, a radiation antenna, and a medium, and the chip refers to a passive ultra-high frequency RFID chip with a temperature measurement function. The radiation antenna refers to an electromagnetic wave energy receiving and reflecting device connected to the two ends of the chip RF+ and RF- (GND) that can match the corresponding chip. The medium includes ceramics, PCB, and high-frequency boards. 3. The temperature measurement sensing device according to claim 1, characterized in that one or more grooves are provided on the side of the nut, and a temperature measurement label is fixed on each groove. The uniform cover is provided with a shell cover. 4. The temperature measurement sensing device according to claim 2, characterized in that the thickness of the nut is 7mm-10mm, the slot width of the nut is 5.5mm-7mm, and the width of the temperature measurement label is 4mm-6mm, and the distance between the chip in the temperature measurement label and the side near the side wall of the groove is 0mm-1mm. 5. The temperature measurement sensing device according to claim 2, characterized in that the angle between the main polarization direction of the temperature measurement label and the normal direction of the nut does not exceed 30 degrees, and the temperature measurement label is any edge. Anti-metal tags whose size in the normal direction of the nut are greater than or equal to 4mm. 6. The temperature measurement sensing device according to claim 5, characterized in that the temperature measurement label is a ceramic label with a length*width=5mm*5mm and a dielectric constant between 140 and 180 or a length*width= Ceramic labels of 10mm*5mm and dielectric constant greater than 50. 7. A cable joint installation structure, characterized in that it includes the temperature sensing device according to claims 1-6, a screw, a plug, a metal cup, and a copper nose, and the metal cup is embedded in the plug. Inside, one end of the screw is inserted into the metal cup body, and the other end extends to the outside of the plug. A copper nose is hung on the end of the screw away from the plug, and a temperature sensing device and a spring are set on the screw. Spacers, regular spacers, positioning pads and several other pads. 8. The cable joint installation structure according to claim 7, wherein the spring gasket is an unclosed ring body, the ordinary gasket is a closed ring structure, and the positioning pad and Other liners are hollow sheets with thickness. 9. The cable joint installation structure according to claim 7, characterized in that the positioning pad is used to control the distance between the metal cup mouth and the copper nose surface; the other pads are provided with 1-4 The installation position can be freely set on the screw space between the metal cup body and the copper nose; the positioning pad and other pads can be used alone or in any combination, both of which are used to provide the rim of the metal cup body. and create an insulating gap between the copper nose surface. 10. The cable joint installation structure according to claim 9, characterized in that by increasing the thickness of ordinary gaskets or spring gaskets, the function of any other gasket can be equivalently replaced. By increasing the thickness of ordinary gaskets or spring gaskets, The outer diameter can effectively replace the positioning pad.