Device and method for detecting connection state of insulator and metal piece of drop-out fuse

Abstract

The invention discloses a device for detecting the connection state of a drop-out fuse insulator and a metal piece and a detection method, the connection state between the drop-out fuse insulator and the metal piece is evaluated by detecting the relative displacement between the drop-out fuse insulator and the metal piece in real time, and then whether the insulator has defects or not is judged. The device comprises a high-precision displacement sensor, a fixing plate, a fixing bolt, a display instrument and a power supply module. The high-precision displacement sensor is fixed on a metal piece of the drop-out fuse through a fixing plate and a fixing bolt, and is connected to a sensor input end of the display instrument. After power is supplied to the display instrument, the display instrument displays the current relative displacement between the insulator and the metal piece, and if the relative displacement is not within the upper and lower limit safety parameter range of the relative displacement, an alarm is given to prompt a worker to check and replace. The whole device has the advantages of simple structure, real-time detection, high detection precision and high reliability. And communication with an upper computer is realized, data are transmitted back in real time, and the real-time performance and accuracy of detection are ensured.

Description

Technical Field

[0001] The invention relates to electrical equipment detection technology, in particular to a detection device for judging the connection state of an insulator and a metal part of a drop-out fuse based on detecting whether relative displacement occurs between the insulator and the metal part, and belongs to the field of power system monitoring. Background Art

[0002] Drop-out fuses are vital overload protection devices in power systems. In Northwest my country, frequent strong winds and significant temperature differences between day and night pose a severe challenge to the reliability of fuses. Drop-out fuses are mainly composed of insulators, fixed ends (metal parts), fuse tubes, inlet / outlet terminals, and moving / static contacts. As an important component of the fuse, the insulator not only supports the entire device, but also has an insulating function. Its structural characteristics make the connection between the fixed end (metal parts) and the insulator a weak link where stress is concentrated, which can easily lead to fuse failure, resulting in serious economic losses and waste of resources.

[0003] The failure of porcelain insulators may be manifested as porcelain body fracture, cement adhesive swelling due to moisture absorption, or cement adhesive being squeezed out of the porcelain bottle glue hole when the insulator is subjected to large stress but not broken. In either case, the connection between the fixed end (metal part) and the insulator will eventually loosen and fail. In the early stage of failure, this looseness may be very hidden and difficult to detect with the naked eye, so it is necessary to install a detection device.

[0004] As a commonly used protective device in power systems, the operating status of the insulator of the drop-out fuse is crucial to the safety of the entire system. Traditional detection methods often rely on ultrasonic detection and other methods, which have many operational restrictions and low detection efficiency. Therefore, it is necessary to develop a high-precision detection device that can detect the connection status of the insulator and metal parts of the drop-out fuse in real time. Summary of the invention

[0005] The purpose of the present invention is to provide a high-precision detection device that can detect the connection status of a drop-out fuse insulator and a metal part in real time. The device is based on the principle that different materials have different linear expansion coefficients when heated and different deformation amounts when subjected to force. The device detects the relative displacement between the drop-out fuse insulator and the metal part in real time to evaluate the connection status between the two, and then judges whether the insulator has defects.

[0006] The technical solution of the present invention is: a device for detecting the connection state of an insulator and a metal part of a drop-out fuse, wherein a metal part is fixed in the middle of the insulator of the drop-out fuse, a fixing plate is installed on the metal part with fixing bolts, the fixing plate is a special-shaped bending structure, a high-precision displacement sensor is fixed at one end of the fixing plate, the high-precision displacement sensor is connected to a display instrument through a wire, and the relative displacement data of the high-precision displacement sensor is transmitted to the display instrument. The display instrument is used to set upper and lower limit safety parameters of the relative displacement and display the initial relative distance between the insulator and the metal part. The high-precision displacement sensor is used to measure the relative displacement between the insulator and the metal part. When the connection state of the insulator and the metal part is good, the relative position of the insulator and the metal part is determined, and the displacement is 0. When the connection state of the insulator and the metal part is poor, the relative displacement from the insulator to the metal part measured by the high-precision displacement sensor changes, that is, it is judged that the insulator and the metal part have moved relative to each other and a defect has occurred. When the upper and lower limit safety parameters of the relative displacement are exceeded, an alarm is issued.

[0007] Preferably, the alarm mode is an indicator light, and an upper limit alarm output indication and a lower limit alarm output indication are provided on the display instrument panel.

[0008] The upper and lower limit safety parameters of the displacement are adjusted by the setting key, shift key, increase key and decrease key on the display instrument panel, and the numbers are displayed in the display window.

[0009] The display instrument is powered by a power module, and the power module and the display instrument are detachably connected.

[0010] The repetitive accuracy of the high-precision displacement sensor + the resolution of the high-precision displacement sensor is ≤0.01 mm.

[0011] Furthermore, the bolt holes of the fixing plate are designed as oblong holes, and the corresponding bolt holes on the metal parts are designed as round holes, and the installation position of the fixing plate relative to the metal parts is adjusted by the length range of the oblong holes.

[0012] Furthermore, the display instrument has a data transmission function, and the RS485 communication terminal of the display instrument communicates with the host computer, and transmits the relative displacement data between the insulator and the metal part and the alarm status signal data back to the host computer system in real time.

[0013] A method for detecting the connection state of a device for detecting the connection state of an insulator of a drop-out fuse and a metal part, loosening and tightening a fixing bolt to fine-tune the distance between a fixing plate and the metal part, observing the indication in a display window, and making the indication between 25% and 75% of the range of a high-precision displacement sensor, which is a centering indication; Use the setting key, shift key, increase key and decrease key of the display instrument to set the upper and lower limit safety parameters of the relative displacement. The upper limit safety parameter of the relative displacement = the middle reading + (the repeatability of the high-precision displacement sensor + the resolution of the high-precision displacement sensor), and the lower limit safety parameter of the relative displacement = the middle reading - (the repeatability of the high-precision displacement sensor + the resolution of the high-precision displacement sensor). During use, relative displacement occurs between the insulator and the metal parts, which is compared with the upper and lower limit safety parameters of the relative displacement. When the relative displacement is greater than the upper limit safety parameter of the relative displacement, the indicator light of the upper limit alarm output indication of the display instrument lights up, and the upper limit alarm output terminal changes from normally open to normally closed, prompting the staff to check and replace; when the relative displacement is less than the lower limit safety parameter of the relative displacement, the indicator light of the lower limit alarm output indication of the display instrument lights up, and the lower limit alarm output terminal changes from normally open to normally closed, prompting the staff to check and replace.

[0014] The beneficial effects of the present invention are as follows: the relative displacement between the insulator and the metal part is measured by a high-precision displacement sensor, which can monitor in real time and has an alarm function to prompt the staff to check and replace in time. The device is simple in composition, easy to use, and has high detection accuracy and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The overall structure of the device of the present invention is shown; Figure 2 The use process of the device of the present invention is illustrated; Figure 3 Demonstrates the module interactions during the detection process. DETAILED DESCRIPTION

[0016] The device includes a high-precision displacement sensor 2 and a display instrument 6. When the connection state of the insulator 1 and the metal part 5 is intact, the metal part 5 and the insulator 1 are in good contact, and the relative position of the insulator 1 and the metal part 5 is determined. The high-precision displacement sensor 2 is used to measure the relative displacement of the metal part 5 to the insulator 1 (the high-precision displacement sensor 2 is connected to the metal part 5, and moves with the metal part 5. The distance change between the sensor probe and the surface of the insulator from the initial state to a period of time is measured). When the connection between the insulator 1 and the metal part 5 is poor, the relative displacement of the metal part 5 to the insulator 1 measured by the high-precision displacement sensor 2 will change, and it can be judged that the insulator has a defect.

[0017] Specifically, it is a device for detecting the connection state of an insulator and a metal part of a drop-out fuse. A metal part 5 is fixed in the middle of the insulator of the drop-out fuse. A fixing plate 3 is installed on the metal part 5 with fixing bolts 4. The fixing plate 3 is a special-shaped bending structure. A high-precision displacement sensor 2 is fixed at one end of the fixing plate 3. The high-precision displacement sensor 2 is connected to a display instrument 6 through a wire. The relative displacement data of the high-precision displacement sensor 2 is transmitted to the display instrument 6. The display instrument 6 is used to set the upper and lower limit safety parameters of the relative displacement and display the initial relative distance between the insulator 1 and the metal part 5. The high-precision displacement sensor 2 is used to measure the relative displacement between the insulator 1 and the metal part 5. When the connection state of the insulator 1 and the metal part 5 is good, the relative position of the insulator 1 and the metal part 5 is determined, and the displacement is 0. When the connection state of the insulator 1 and the metal part 5 is poor, the relative displacement from the insulator 1 to the metal part 5 measured by the high-precision displacement sensor 2 changes, that is, it is judged that the insulator and the metal part have moved relative to each other and defects have occurred. When the upper and lower limit safety parameters of the relative displacement are exceeded, an alarm is issued.

[0018] The preferred alarm mode is an indicator light, and an upper limit alarm output indication 7 and a lower limit alarm output indication 8 are provided on the display instrument 6 panel.

[0019] The upper and lower limit safety parameters of the displacement are adjusted by the setting key 9, the shift key 10, the increase key 11, and the decrease key 12 provided on the panel of the display instrument 6, and the numbers are displayed in the display window 14.

[0020] The display instrument 6 is powered by a power module 13 , and the power module 13 and the display instrument 6 are detachably connected to facilitate charging.

[0021] In order to achieve fine adjustment, the bolt holes of the fixing plate 3 are designed as oblong holes, and the corresponding bolt holes on the metal part 5 are designed as round holes. The installation position of the fixing plate 3 relative to the metal part 5 is adjusted by the length range of the oblong holes.

[0022] The display instrument 6 may also have a data transmission function. The RS485 communication terminal 20 of the display instrument 6 communicates with the host computer, and transmits the relative displacement data between the insulator 1 and the metal part 5 and the alarm status signal data back to the host computer system in real time.

[0023] Use of the device: The high-precision displacement sensor 2 is connected to the sensor input terminal 16 of the display instrument 6. The power module 13 is connected to the power input terminal 15 of the display instrument 6 to supply power to the display instrument 6. After the display instrument 6 is powered, the display window 14 displays the initial relative distance between the current sensor probe and the surface of the insulator. Loosen and tighten the fixing bolt 4 to fine-tune the relative installation position between the fixing plate 3 and the metal part 5, and observe the indication of the display window 14 so that the indication is between 25%-75% of the range of the high-precision displacement sensor 2. This indication is the adjustment indication. The upper and lower limit safety parameters of the relative displacement are set by the setting key 9, shift key 10, increase key 11, and decrease key 12 of the display instrument 6. The upper limit safety parameter of the relative displacement = the adjustment indication + (the repeatability of the high-precision displacement sensor + the resolution of the high-precision displacement sensor), and the lower limit safety parameter of the relative displacement = the adjustment indication - (the repeatability of the high-precision displacement sensor + the resolution of the high-precision displacement sensor). The repeatability of the high-precision displacement sensor 2 + the resolution of the high-precision displacement sensor ≤ 0.01mm.

[0024] When relative displacement occurs between the insulator 1 and the metal part 5 during use and the relative displacement is greater than the upper limit safety parameter of the relative displacement, the indicator light of the upper limit alarm output indication 7 of the display instrument 6 lights up, and the upper limit alarm output terminal 17 changes from normally open to normally closed, prompting the staff to check and replace it.

[0025] When relative displacement occurs between the insulator 1 and the metal part 5 during use and the relative displacement is less than the lower limit safety parameter of the relative displacement, the indicator light of the lower limit alarm output indication 8 of the display instrument 6 lights up, and the lower limit alarm output terminal 18 changes from normally open to normally closed, prompting the staff to check and replace it.

[0026] The transmission output terminal 19 of the display instrument 6 transmits the displacement signal into a 4-20mA current signal output. The RS485 communication terminal 20 of the display instrument 6 supports TC ASCII and Modbus RTU communication protocols, communicates with the host computer through parameter settings, and transmits the relative displacement data between the insulator 1 and the metal part 5 and the alarm status signal and other data back to the host computer system in real time.

Claims

1. A device for detecting the connection status of an insulator and a metal part of a drop-out fuse, characterized in that: A metal piece (5) is fixed in the middle of the insulator of the drop-out fuse, a fixing plate (3) is installed on the metal piece (5) by means of fixing bolts (4), the fixing plate (3) is a special-shaped bending structure, a high-precision displacement sensor (2) is fixed at one end of the fixing plate (3), the high-precision displacement sensor (2) is connected to a display instrument (6) via a wire, relative displacement data of the high-precision displacement sensor (2) is transmitted to the display instrument (6), the display instrument (6) is used to set upper and lower limit safety parameters of the relative displacement, and to display the initial relative distance between the insulator (1) and the metal piece (5). The high-precision displacement sensor (2) is used to measure the relative displacement between the insulator (1) and the metal part (5). When the insulator (1) and the metal part (5) are in a good connection state, the relative position of the insulator (1) and the metal part (5) is determined and the displacement is 0. When the insulator (1) and the metal part (5) are in a bad connection state, the relative displacement from the insulator (1) to the metal part (5) measured by the high-precision displacement sensor (2) changes, that is, it is judged that the insulator and the metal part have moved relative to each other and a defect has occurred. When the relative displacement exceeds the upper and lower limit safety parameter parameters, an alarm is issued.

2. A device for detecting the connection status between an insulator and a metal part of a drop-out fuse according to claim 1, characterized in that: The alarm mode is an indicator light, and an upper limit alarm output indication (7) and a lower limit alarm output indication (8) are provided on the display instrument (6) panel.

3. The device for detecting the connection status between the insulator and the metal part of a drop-out fuse according to claim 1, characterized in that: The upper and lower limit safety parameters of the displacement are adjusted by using a setting key (9), a shift key (10), an increase key (11), and a decrease key (12) provided on the panel of the display instrument (6), and the digital display is displayed in the display window (14).

4. A device for detecting the connection status between an insulator and a metal part of a drop-out fuse according to claim 1, characterized in that: The display instrument (6) is powered by a power module (13), and the power module (13) and the display instrument (6) are detachably connected.

5. The device for detecting the connection status between the insulator and the metal part of a drop-out fuse according to claim 1, characterized in that: The repeatability of the high-precision displacement sensor (2) + the resolution of the high-precision displacement sensor is ≤ 0.01 mm.

6. The device for detecting the connection status between the insulator and the metal part of a drop-out fuse according to claim 1, characterized in that: The bolt through-holes of the fixing plate (3) are designed as oblong holes, and the bolt through-holes on the corresponding metal member (5) are designed as round holes, and the installation position of the fixing plate (3) relative to the metal member (5) is adjusted by the length range of the oblong holes.

7. The device for detecting the connection status between the insulator and the metal part of a drop-out fuse according to claim 1, characterized in that: The display instrument (6) has a data transmission function. The RS485 communication terminal (20) of the display instrument (6) communicates with the host computer and transmits the relative displacement data between the insulator (1) and the metal part (5) and the alarm status signal data back to the host computer system in real time.

8. The method for detecting the connection state of the device for detecting the connection state of the insulator and the metal part of the drop-out fuse according to claim 3, characterized in that: Loosen and tighten the fixing bolt (4) to fine-tune the distance between the fixing plate (3) and the metal part (5), and observe the reading in the display window (14) so ​​that the reading is between 25% and 75% of the range of the high-precision displacement sensor (2). This reading is the mid-adjustment reading; The upper and lower limit safety parameters of the relative displacement are set by the setting key (9), the shift key (10), the increase key (11), and the decrease key (12) of the display instrument (6). The upper limit safety parameter of the relative displacement = the center reading + (the repeatability of the high-precision displacement sensor + the resolution of the high-precision displacement sensor), and the lower limit safety parameter of the relative displacement = the center reading - (the repeatability of the high-precision displacement sensor + the resolution of the high-precision displacement sensor); During use, relative displacement occurs between the insulator (1) and the metal part (5), and is compared with the upper and lower limit safety parameters of the relative displacement. When the relative displacement is greater than the upper limit safety parameter of the relative displacement, the indicator light of the upper limit alarm output indication (7) of the display instrument (6) lights up, and the upper limit alarm output terminal (17) changes from normally open to normally closed, prompting the staff to check and replace; when the relative displacement is less than the lower limit safety parameter of the relative displacement, the indicator light of the lower limit alarm output indication (8) of the display instrument (6) lights up, and the lower limit alarm output terminal (18) changes from normally open to normally closed, prompting the staff to check and replace.

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