Online temperature measurement method and device for cable joints of high-voltage equipment

Abstract

The present invention provides an on-line temperature measurement method and device for a cable joint of a high-voltage device. Each current induction coil induces a current, which, after being rectified and regulated, provides working power for its respective temperature sensor, processing unit, and wireless transmission unit. Each temperature sensor sends the temperature signal of each metal conductor into its respective processing unit, and the processing unit sends the monitored temperature signal and the corresponding digital identification code in the memory together through the wireless transmission unit. The display instrument receives each digital signal and identifies three corresponding cable joints through the digital identification code, and displays the on-line temperature values of each phase of the measured cable joint. When the temperature value of any one phase of the cable joint exceeds the set value, the display unit alarms the temperature of this phase. In the present invention, during the operation of the cable joint of the high-voltage device, the temperature change can be quickly reflected by the temperature sensor, which makes the temperature sensor respond faster and the measurement more accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of high-voltage detection, and particularly to an on-line temperature measurement method and device for a cable joint of a high-voltage device. Background Art

[0002] The output ends of high-voltage devices such as high-voltage switches, transformers, and cable branch boxes all adopt insulating sleeves formed by pouring an insulating material outside a metal good conductor in the middle, and then connecting the cable joints. This connection method has the advantages of good insulation performance, convenient connection, and flexible combination. In the prior art, methods such as optical fiber temperature measurement method, infrared light-emitting tube output transmission method, and indirect temperature measurement on the surface of high-voltage insulators are generally used for on-line temperature measurement of cable joints. However, the disadvantage of the optical fiber temperature measurement method is that the cost is expensive, the installation structure is complex, and it is difficult to balance the temperature signal sampling and the insulation distance. The disadvantage of the infrared light-emitting tube output transmission method is that the problems of line-of-sight of the infrared light-emitting output signal and the creepage distance of high-voltage safety must be solved. The indirect temperature measurement method has poor real-time performance, is easily affected by the ambient temperature, etc., and the accuracy is not high.

[0003] In order to solve the disadvantages of the three methods, a patent with publication number CN101319938B discloses an on-line temperature measurement method and device for a cable joint of a high-voltage device (hereinafter referred to as "this solution"), where a temperature sensor is attached to the surface of a metal conductor, a current induction coil is sleeved on the metal conductor, and a power supply circuit, a microprocessor, and a wireless transmitter are installed on the metal conductor through a circuit board and sealed in an insulator, etc. Without changing the original standard connection method and without affecting the original insulation performance, the temperature of the cable joint of the high-voltage device can be monitored on-line in a timely and accurate manner. However, this solution is to connect the metal conductor to the cable joint, and then achieve temperature measurement by conducting heat to the metal conductor. Since the two are connected, it is an indirect heat conduction, and the temperature of the cable joint is indirectly monitored through the metal conductor. Therefore, the monitoring method and accuracy still need to be further improved. Summary of the Invention

[0004] The purpose of the present invention is to provide an on-line temperature measurement method and device for a cable joint of a high-voltage device to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] An on-line temperature measurement method for a cable joint of a high-voltage device includes the following steps:

[0007] After sleeving a current induction coil on a conductor interface, install it at one end inside the lumen of the insulating sleeve;

[0008] Install a processing unit and a wireless transmission unit on a circuit board;

[0009] Seal the circuit board, current induction coil and temperature sensor inside the body of the insulating sleeve;

[0010] Then insert the detection end of the temperature sensor deep into the lumen;

[0011] Write the digital identification codes of the three output terminals of the cable joint to be measured into the memories of their respective processing units;

[0012] The three conductor interfaces are respectively sleeved on the three-phase output terminals of the cable of the high-voltage equipment to form a sealed cavity. Inject liquid into the cavity, and then induce current through each current induction coil. After rectification and voltage regulation, it provides working power for their respective temperature sensors, processing units and wireless transmission units;

[0013] Each temperature sensor sends the temperature signals of each metal conductor into their respective processing units. The processing units send the monitored temperature signals and the corresponding digital identification codes in the memory together through the wireless transmission units;

[0014] The wireless receiving unit installed on or outside the electric cabinet receives radio signals from each path, demodulates them into digital signals and transmits them to the display unit. The display instrument receives digital signals from each path and identifies the three corresponding cable joints through the digital identification codes, and displays the online temperature values of each phase of the cable joints to be measured. When the temperature value of any phase of the cable joint exceeds the set value, the display unit alarms for the temperature of this phase.

[0015] To achieve the above object, the present invention also provides the following technical solutions:

[0016] An on-line temperature measurement device for a cable joint of a high-voltage equipment, comprising:

[0017] An insulating sleeve having a lumen;

[0018] Conductor interfaces, sleeved inside the current induction coils, for respectively sleeving with the three output terminals of the cable joint to be measured and forming a sealed cavity;

[0019] A circuit board, encapsulated inside the insulating sleeve, and installed with a processing unit and a wireless transmission unit connected to the processing unit;

[0020] A temperature sensor, sealed inside the body of the insulating sleeve, connected to the processing unit, and extending deep into the lumen through the detection end;

[0021] A current induction coil, installed at one end inside the lumen, for supplying power to the temperature sensor and the circuit board;

[0022] The receiving end of the wireless receiving unit located outside the insulator communicates with the transmitting end of the wireless transmission unit, and the output end of the wireless receiving unit is connected to the display unit;

[0023] Liquid is injected into the cavity.

[0024] Preferably, it further includes a rotating rod. There are two rotating rods, and one end of each rotating rod is inserted into the insulating sleeve and spans across the lumen, so as to enclose the lumen between the two rotating rods into a cavity. The other end of the rotating rod is located outside the insulating sleeve.

[0025] Preferably, the rotating rod is rotatably mounted on the insulating sleeve through a bushing, and has a through hole to communicate the cavity with the lumen outside the cavity.

[0026] Preferably, the lumen has a groove body, and an elastomer for blocking the through hole is provided in the groove body.

[0027] Preferably, an indicating line is engraved on the insulating sleeve at a position corresponding to the elastomer, and an indicating arrow for cooperating with the indicating line is provided at the other end of the rotating rod.

[0028] Preferably, a liquid injection channel for communicating with the cavity is provided on the insulating sleeve.

[0029] Preferably, a bladder is provided in the cavity, and the bladder is connected with a bladder channel. The end of the bladder channel penetrates to the outside of the insulating sleeve.

[0030] Preferably, the bladder channel is divided into a first channel and a second channel by a partition in the bladder channel. The end of the partition penetrates into the bladder to divide the bladder into two bladder units.

[0031] Preferably, a through port is provided on the partition between the two bladder units.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] In the present invention, by providing a lumen, the liquid medium filled in the lumen can quickly reflect the temperature change through the temperature sensor when the cable joint of the high-voltage equipment is working. This enables the temperature sensor to respond quickly and the measurement to be more accurate.

[0034] In the present invention, by adjusting the communication state between the lumen and the cavity through the rotating rod, the temperature of the cable joints at each end of the insulating sleeve can be measured independently by the sensor, so that when a temperature anomaly occurs, it can be further analyzed which side / section position is specifically involved.

[0035] In the present invention, the temperature signal sampling is accurate, which not only solves the on-line temperature measurement function, but also maintains the insulation strength of the original equipment. Without changing the original standard connection method and without affecting the original insulation performance, the on-line temperature measurement problem of the cable joint of the high-voltage equipment is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a schematic block diagram of the present invention;

[0037] Figure 2 is a schematic diagram of the overall structure of the present invention;

[0038] Figure 3 of the present invention Figure 2 is a schematic diagram of the transfer rod rotating 90 degrees;

[0039] Figure 4 is a schematic diagram of the through hole and the lumen of the present invention being connected;

[0040] Figure 5 is a schematic diagram of the through hole and the lumen of the present invention being disconnected;

[0041] Figure 6 is a schematic diagram of the indication line and the indication arrow cooperating and pointing in the present invention.

[0042] In the figure: 1 insulating sleeve, 2 middle part, 3 lumen, 4 conductor interface, 5 current induction coil, 6 temperature sensor, 7 detection end, 8 rotating rod, 9 cavity, 10 bladder, 11 bushing, 12 liquid injection channel, 13 bladder channel, 14 partition, 15 first channel, 16 second channel, 17 port, 18 through hole, 19 elastomer, 20 groove, 21 indication line, 22 indication arrow. Specific embodiments

[0043] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0044] Embodiment:

[0045] Please refer to Figures 1 to 6 , the present invention provides a technical solution:

[0046] An on-line temperature measurement method for a cable joint of a high-voltage device, the steps of which are:

[0047] Step 1, after sleeving the current induction coil 5 on the conductor interface 4, install it at one end in the lumen 3 of the insulating sleeve 1;

[0048] Step 2, install the processing unit and the wireless transmission unit on the circuit board;

[0049] Step 3, seal the circuit board, the current induction coil 5 and the temperature sensor 6 in the body of the insulating sleeve 1;

[0050] Step 4, then insert the detection end 7 of the temperature sensor 6 into the lumen 3,

[0051] Step 5: Write the digital identification codes of the three output terminals of the cable joint under test (i.e., the "high-voltage equipment cable joint" or "cable joint" hereinafter) into the memories of their respective processing units;

[0052] Step 6: The three conductor interfaces 4 are respectively sleeved on the three-phase output terminals of the high-voltage equipment cable, the lumen 3 forms a sealed cavity 9, inject liquid into the cavity 9, and then induce current through each current induction coil, and after rectification and voltage stabilization, provide working power for their respective temperature sensors 6, processing units and wireless transmission units;

[0053] Step 7: Each temperature sensor 6 sends the temperature signals of each metal conductor into its respective processing unit, and the processing unit sends the monitored temperature signals and the corresponding digital identification codes in the memory together through the wireless transmission unit;

[0054] Step 8: The wireless receiving unit installed on or outside the electric cabinet receives each radio signal, demodulates it into a digital signal and transmits it to the display unit. The display instrument receives each digital signal and identifies the three corresponding cable joints through the digital identification codes, and displays the online temperature values of each phase of the cable joint under test. When the temperature value of any phase of the cable joint exceeds the set value, the display unit alarms for the temperature of this phase.

[0055] As Figure 2 shown, the present invention also discloses an on-line temperature measuring device for a high-voltage equipment cable joint, which has:

[0056] An insulating sleeve 1, having a lumen 3;

[0057] A conductor interface 4, sleeved in a current induction coil 5, used to be respectively sleeved on the three output terminals of the cable joint under test and form a sealed cavity 9;

[0058] A circuit board, encapsulated in the insulating sleeve 1, and installed with a processing unit and a wireless transmission unit connected to the processing unit;

[0059] A temperature sensor 6, sealed in the body of the insulating sleeve 1, connected to the processing unit, and extending into the lumen 3 through a detection end 7;

[0060] A current induction coil 5, installed at one end in the lumen 3, used to supply power for the temperature sensor 6 and the circuit board;

[0061] The receiving end of the wireless receiving unit located outside the insulator communicates with the transmitting end of the wireless transmission unit, and the output end of the wireless receiving unit is connected to the display unit;

[0062] Liquid is injected into the cavity 9. The insulating sleeve 1 is provided with a liquid injection channel 12 for communicating with the cavity 9.

[0063] In the present invention, the conductor interface 4 is sleeved on the three output ends of the cable joint to be measured. For example, if a general cable joint has threaded holes, then the two are connected by screwing. For example, if there are no threads, the two are sleeved. To ensure the sealing performance after the two are connected, a sealing ring, sealing tape or injection sealing can be wrapped outside, which is determined according to the actual use situation on site. When the two ends of the insulating sleeve 1 are respectively connected to the cable joint of the high-voltage equipment, the cavity 3 becomes a sealed cavity at this time. A liquid medium, such as water, can be injected into the cavity 9 / cavity 3 through the liquid injection channel 12. Thus, the liquid medium can directly contact the cable joint of the high-voltage equipment, and the heat generated by the cable joint of the high-voltage equipment during operation can be directly absorbed by the liquid medium, so that the temperature change of the cable head can be accurately reflected, and then detected by the temperature sensor 6. Since the heat conduction of the cable joint of the high-voltage equipment to the liquid medium is better than that of metal and other conductor media, the liquid medium filled in the cavity 3 can quickly reflect the temperature change of the cable joint of the high-voltage equipment through the temperature sensor 6 during operation. This makes the temperature sensor 6 respond quickly and the measurement is more accurate.

[0064] The on-line temperature measurement device of the present invention further includes a rotating rod 8. There are two rotating rods 8, and one end is inserted into the insulating sleeve 1 and straddles the cavity 3, so that the cavity 3 located between the two rotating rods 8 is enclosed into a cavity 9, and the other end of the rotating rod 8 is located outside the insulating sleeve 1. The rotating rod 8 is rotatably installed on the insulating sleeve 1 through a bushing 11 and has a through hole 18 to communicate the cavity 9 with the cavity 3 outside the cavity 9. The cavity 3 has a groove 20, and an elastomer 19 for blocking the through hole 18 is provided in the groove 20.

[0065] In the present invention, considering injecting a liquid medium into the cavity 3, in order to make the conductor interface 4 at the inner end of the insulating sleeve 1 be completely connected to the cable joint and then make the injected liquid medium contact the cable joint, the liquid medium can be first injected into the cavity 9. After it is confirmed that the cable joint is connected to the insulating sleeve 1 and sealed, the liquid medium stored in the cavity 9 is released to contact the cable joint. This can prevent the liquid medium from leaking in advance. Specifically, as Figure 2 and Figures 4 to 5 described, by rotating the rotating rod 8, the relative position of the through hole 18 and the elastomer 19 changes until the through hole 18 communicates with the cavity 3, so that the cavity 3 on both sides of the rotating rod 8 and the cavity 9 can be communicated through the through hole 18. When it is necessary to close the communication state between the cavity 3 on both sides of the rotating rod 8 and the cavity 9 again, the rotating rod 8 is rotated to make the through hole 18 rotate towards the position of the elastomer 19, so that the elastomer 19 blocks the through hole 18.

[0066] In the present invention, as Figure 6As shown, an indicating line 21 is engraved at a position on the insulating sleeve 1 corresponding to the elastomer 19, and an indicating arrow 22 for cooperating with the indicating line 21 is provided at the other end of the rotating rod 8. When the rotating rod 8 rotates, when the indicating arrow 22 thereon rotates to point to the indicating line 21, it indicates that the elastomer 19 has blocked the through hole 18, and at this time, the lumen 3 and the cavity 9 cannot be communicated. Moreover, by adjusting the connection state of the lumen 3 and the cavity 9 through the rotating rod 8, the temperature of the cable joint at each end of the insulating sleeve 1 can be measured independently by the sensor 6, so that when the temperature is abnormally high, it can be further analyzed which side / section position is specifically involved. There is a certain frictional force between the rotating rod 8 and the insulating sleeve 1, so that only when a certain torque is applied can the rotating rod 8 be rotated.

[0067] In the present invention, as Figure 2 shown, considering that the temperature of the cable joint of the high-voltage equipment can reach 80 °C or even higher during operation, the middle part of the insulating sleeve 1 is convex, and the inner diameter of the cavity 9 is also larger than the inner diameters of the two lumen 3 on both sides, so that more liquid medium can be filled in the insulating sleeve 1 under the same size, and the bladder 10 can be accommodated, thereby alleviating the influence of temperature rise on the insulating sleeve 1.

[0068] In the present invention, as Figure 2 shown, a bladder 10 is provided in the cavity 9, and the bladder 10 is connected with a bladder channel 13, and the end of the bladder channel 13 penetrates to the outside of the insulating sleeve 1. The bladder channel 13 is divided into a first channel 15 and a second channel 16 by a partition 14 in the bladder channel 13, and the end of the partition 14 penetrates into the bladder 10 to divide the bladder 10 into two bladder units. A through port 17 is provided on the partition 14 between the two bladder units. By providing the bladder, the influence of temperature rise on the insulating sleeve 1 can be alleviated. Moreover, after the temperature of the cable joint / insulating sleeve 1 exceeds the maximum value, a circulating cooling medium can be injected into the bladder 10 through the bladder channel 13 (input / pumped through the first channel 15 or the second channel 16, passing through the through port 17, and then output / pumped out through the second channel 16 or the first channel 15), so as to realize the rapid heat dissipation of the device. Usually during use, the cooling medium can be not injected into the bladder 10 first, and this can be adopted only when the temperature is too high and exceeds the warning. In the present invention, the bladder 10 can have a certain flexibility. In this way, when the liquid medium is injected into the cavity 9 / lumen 3 through the liquid injection channel 12, the bladder 10 will not be flattened first. In this way, as long as the temperature of the cable joint continuously rises, the bladder 10 will gradually shrink to a certain extent, so that when the liquid medium expands due to heat, it will not affect the insulating sleeve 1, but the heat is dissipated through the shrinkage of a certain volume of the bladder 10 and through the bladder channel 13, thereby protecting the insulating sleeve 1 and enabling the entire device to work properly.

[0069] For the present invention, the parts not described herein may be the same as the prior art, or be well-known technologies, or can be implemented by using the prior art, and thus will not be elaborated herein.

[0070] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An on-line temperature measurement device for a cable joint of a high-voltage device, characterized in that, Comprising: An insulating bushing (1) having a lumen (3); A conductor interface (4) sleeved inside a current induction coil (5) for respectively socketing with three output ends of a cable joint to be measured and forming a sealed cavity (9); A circuit board encapsulated inside the insulating bushing (1) and provided with a processing unit and a wireless transmitting unit connected to the processing unit; A temperature sensor (6) sealed inside the body of the insulating bushing (1), connected to the processing unit, and having a detection end (7) extending into the lumen (3); A current induction coil (5) installed at one end inside the lumen (3) for supplying power to the temperature sensor (6) and the circuit board; The receiving end of a wireless receiving unit located outside the insulator communicates with the transmitting end of the wireless transmitting unit, and the output end of the wireless receiving unit is connected to a display unit; A liquid is injected into the cavity (9); It further includes a rotating rod (8), there are two of the rotating rods (8), and one end is inserted into the insulating bushing (1) and spans across the lumen (3), thereby enclosing the lumen (3) between the two rotating rods (8) to form a cavity (9), and the other end of the rotating rod (8) is located outside the insulating bushing (1); The rotating rod (8) is rotatably installed on the insulating bushing (1) through a bushing (11) and has a through hole (18) to enable the cavity (9) to communicate with the lumen (3) outside the cavity (9).

2. The on-line temperature measuring device for a cable joint of a high-voltage device according to claim 1, characterized in that, The lumen (3) has a groove body (20), and an elastomer (19) for blocking the through hole (18) is arranged in the groove body (20).

3. The on-line temperature measuring device for the cable joint of a high-voltage device according to claim 2, characterized in that, An indicating line (21) is engraved on the insulating bushing (1) at a position corresponding to the elastomer (19), and an indicating arrow (22) for cooperating with the indicating line (21) is provided at the other end of the rotating rod (8).

4. The on-line temperature measuring device for a cable joint of a high-voltage device according to claim 1, characterized in that, The insulating bushing (1) is provided with a liquid injection channel (12) for communicating with the cavity (9).

5. The on-line temperature measuring device for a high-voltage equipment cable joint according to claim 1, characterized in that, A bladder (10) is arranged inside the cavity (9), and the bladder (10) is connected with a bladder channel (13), and the end of the bladder channel (13) penetrates to the outside of the insulating bushing (1).

6. The on-line temperature measurement device for the cable joint of a high-voltage device according to claim 5, characterized in that, The bladder channel (13) is divided into a first channel (15) and a second channel (16) by a partition plate (14) inside the bladder channel (13), and the end of the partition plate (14) penetrates into the bladder (10) to divide the bladder (10) into two bladder units.

7. The on-line temperature measuring device for a high-voltage equipment cable joint according to claim 6, characterized in that, There is a through port (17) on the partition plate (14) between the two bladder units.

8. An online temperature measurement method for a cable joint of a high-voltage device, using the online temperature measurement device according to any one of claims 1 to 7, characterized in that, Including the following steps: After sleeving the current induction coil (5) on the conductor interface (4), install it at one end inside the lumen (3) of the insulating bushing (1); Install the processing unit and the wireless transmitting unit on the circuit board; Seal the circuit board, the current induction coil (5) and the temperature sensor (6) inside the body of the insulating bushing (1); Then extend the detection end (7) of the temperature sensor (6) into the lumen (3); Write the digital identification codes of the three output ends of the cable joint to be measured into the memories of their respective processing units; Three conductor interfaces (4) are respectively sleeved on the three-phase output ends of the cables of the high-voltage equipment, forming a sealed cavity (9) for the pipe cavity (3). Liquid is injected into the cavity (9), and then currents are induced by each current induction coil. After rectification and voltage stabilization, working power supplies are provided for their respective temperature sensors (6), processing units, and wireless transmission units; Each temperature sensor (6) sends the temperature signals of each metal conductor into their respective processing units, and the processing units send the monitored temperature signals together with the corresponding digital identification codes in the memory through the wireless transmission units; The wireless receiving units installed on or outside the electric cabinet receive all radio signals, demodulate them into digital signals and transmit them to the display unit. The display instrument receives all digital signals and identifies the three corresponding cable joints through the digital identification codes, and displays the on-line temperature values of each phase of the measured cable joints. When the temperature value of any phase of the cable joint exceeds the set value, the display unit alarms for the temperature of that phase.

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