A rapid detection device and detection method for changes in electrical properties of a cable when it is heated

Abstract

The present invention discloses a rapid detection device and a detection method for changes in electrical properties when a cable is heated, and relates to the technical field of cable conductive parameter detection. The present invention performs a high-voltage insulation performance test by using an insulation detection applicator plate and inserting a conductive column, and realizes dynamic detection and regulation of cable temperature rise by combining a closed-loop resistor and a liquid flow pump drive. When the cable load increases or the temperature is abnormal, the system can issue an early warning and reduce the load in time to avoid damage to the insulating material and the risk of short circuit. The use of materials consistent with the cable insulation layer and a closed-loop design improves detection accuracy and reliability.

Description

Technical Field

[0001] The invention relates to the technical field of cable conductive parameter detection, in particular to a rapid detection device and a detection method for a change in electrical performance of a cable when the cable is heated. Background Art

[0002] Traditional cable insulation performance testing relies on manual regular maintenance and local equipment testing. The main means of detection is to indirectly judge the performance status by measuring the voltage and current changes at the cable endpoints. This method has the following disadvantages: untimely detection, regular maintenance cannot reflect the dynamic changes in cable operation in real time, and it is easy to ignore sudden temperature rise or insulation loss problems; insufficient monitoring coverage, existing technology can usually only detect the electrical performance of the entire cable, it is difficult to independently detect the performance of a single battery cell, and it is impossible to locate the problem battery cell; poor material matching, the materials in the detection system are often different from the cable insulation layer, resulting in deviations between the detection results and the actual situation. Summary of the invention

[0003] In order to overcome the defects of the above-mentioned prior art, the present invention provides the following technical solutions: a rapid detection device for changes in electrical properties of a cable when it is heated, comprising a cross-sectional plate, at least two connecting and fixing frames are fixedly installed between the two cross-sectional plates, and two parallel screw rods are slidably installed on each connecting and fixing frame, and the screw rods are arranged along the radial direction of the cross-sectional plate, and the two parallel screw rods are fixedly connected to the crossbeam, and an insulating rubber layer is fixed on the crossbeam, and an electrical performance detection conductive sealing tube is coaxially arranged inside the insulating rubber layer; the electrical performance detection conductive sealing tube is provided with a lower groove, and an inserted conductive column is conductively embedded in the lower groove, and an insulating detection application plate is attached to the outer surface of the insulating rubber layer, and the insulating detection application plate is insulated from the inserted conductive column by the insulating rubber layer, and the insulating detection application plate and the inserted conductive column are electrically connected through a wire; an outer shell is also fixed between the two cross-sectional plates, and the outer shell is arranged on the outside of all the insulating rubber layers, and the outer shell is also provided with a first injection port and a second injection port for injecting insulating rubber into the inner part of the outer shell.

[0004] Preferably, a DC power supply and a current detection unit are provided in series on the wire connected between the insulation detection application plate and the inserted conductive column, so as to detect the insulation performance of the insulation rubber layer.

[0005] Preferably, a nut gear bracket is fixedly installed on each connecting fixing frame, a gap is provided between the nut gear bracket and the connecting fixing frame, two nut gears are provided in the gap, the two nut gears are respectively threadedly sleeved on the corresponding screw rods, and the two nut gears are also connected by a transmission belt.

[0006] Preferably, all the nut gears are meshed with each other through a synchronous gear ring that rotates with all the connecting fixed frames, and an adjusting gear is provided on one of the nut gears for meshing transmission. The adjusting gear rotates with the nut gear bracket, and an adjusting rod shaft is coaxially fixed on the adjusting gear. The adjusting rod shaft extends to the outside of the outer shell, and a hexagonal prism groove is provided on one end of the adjusting rod shaft located on the outside of the outer shell.

[0007] Preferably, the cross-sectional plate is embedded with the same number of fixed conductive sliding contact pieces as the connecting fixed frame, each fixed conductive sliding contact piece is slidably provided with a movable conductive sliding contact piece along the radial direction of the cross-sectional plate, the movable conductive sliding contact piece is conductively arranged with the fixed conductive sliding contact piece, and the fixed conductive sliding contact piece is insulated from the cross-sectional plate, wherein the movable conductive sliding contact piece is conductively fixedly matched with the conductive sealing tube for electrical performance detection.

[0008] Preferably, the interior of the conductive sealing tube for electrical performance detection is hollow, and annular spoilers and disc spoilers are equidistantly arranged in the space inside the conductive sealing tube for electrical performance detection, and the annular spoilers and disc spoilers are used to slow down the flow of insulating liquid inside the conductive sealing tube for electrical performance detection.

[0009] Preferably, both ends of the electrical performance detection conductive sealing tube are provided with drainage ports connected to the inside of the electrical performance detection conductive sealing tube, and the drainage ports extend to the outside of the insulating rubber layer; a liquid discharge pipe and a liquid flow pump are fixedly installed on each connecting fixing frame, wherein the liquid discharge pipe is connected to one of the drainage ports via a guide hose, and the other drainage port is connected to the water inlet of the liquid flow pump via a liquid input pipe and a guide hose, and the water outlet of the liquid flow pump is fixedly connected to a drainage intermediate pipe.

[0010] Preferably, a closed-loop detection tube is fixedly connected between the discharge intermediate tube and the liquid discharge tube, and a closed-loop resistor is arranged inside the closed-loop detection tube.

[0011] A rapid detection method for the change of electrical performance when a cable is heated comprises the following steps: S1, selecting a corresponding number of electrical performance detection conductive sealing tubes according to the number of cable cores to be detected, ensuring that their cross-sectional areas match the cross-sectional areas of the cable cores; selecting an insulating rubber layer with the same material and thickness as the insulating layer of the cable cores to provide a consistent material guarantee for subsequent detection; S2, installing the electrical performance detection conductive sealing tubes in series into the target cable; S3, driving the adjusting gear and the synchronous gear ring by rotating the adjusting rod shaft, so that all the nut gears rotate synchronously, adjusting the radial movement of the lead screw in the cross-sectional plate, and accurately controlling the spacing of the insulating rubber layer to be consistent with the spacing of the cable cores; S4, using a first injection port and a second injection port to gradually inject rubber into the outer shell to keep the same material as the insulating layer on the outside of the cable; S5, detecting the loop current from the application plate to the conductive column through a current detection unit to evaluate the insulating performance of the insulating rubber layer; S6, adjusting the speed of the liquid flow pump according to the change in the resistance value of the closed-loop resistor, and judging the cable load by detecting the change in the power of the liquid flow pump to avoid softening or melting and damage of the insulating rubber layer due to high temperature.

[0012] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention can accurately judge the performance status of the insulating rubber layer by applying high voltage direct current between the insulation detection patch plate and the inserted conductive column and detecting the change of the loop current in real time. This refined detection method can timely detect the decline of insulation performance, avoid the potential short circuit risk in the operation of the cable, and greatly improve the safety of the system and the accuracy of detection; (2) The present invention combines the closed-loop resistor and the liquid flow pump speed adjustment to realize the dynamic monitoring of the cable temperature rise. When the temperature rises rapidly, it can judge whether the load of the cable is in an increasing state by accelerating the circulation of the insulating liquid to reduce the heat exchange time; (3) The present invention effectively avoids the problem of performance mismatch between different materials by selecting an insulating rubber layer with the same material as the cable core insulation layer and injecting an external rubber of the same material, ensuring the authenticity of the detection result and the compatibility between materials, and fundamentally improving the reliability of detection; (4) The entire detection system of the present invention organically combines insulation performance detection, resistance detection, temperature control and early warning system, which can not only detect the performance of each battery core individually, but also comprehensively analyze the overall system status. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0014] Figure 2 It is a schematic diagram of the internal structure of the shell of the present invention.

[0015] Figure 3 It is a schematic diagram of the structure of the closed-loop resistor of the present invention.

[0016] Figure 4 It is a schematic diagram of the structure of the nut and gear of the present invention.

[0017] Figure 5 It is a structural schematic diagram of the movable conductive sliding contact piece of the present invention.

[0018] Figure 6 It is a structural schematic diagram of the insulation detection application plate of the present invention.

[0019] Figure 7 This is a working principle diagram of the liquid flow pump of the present invention.

[0020] In the figure: 101-housing; 102-section plate; 103-first injection port; 104-second injection port; 105-conductive sealing tube for electrical performance detection; 106-circular baffle plate; 107-disc baffle plate; 108-insulating rubber layer; 109-discharge port; 110-insulation detection application plate; 111-inserted conductive column; 112-screw rod; 113-crossbeam; 114-closed-loop detection tube; 115-closed-loop resistor; 116-discharge intermediate tube; 117-liquid flow pump; 118-liquid input pipe; 119-liquid discharge pipe; 120-connecting fixed frame; 121-synchronous gear ring; 122-nut gear; 123-adjusting gear; 124-nut gear bracket; 125-adjusting rod shaft; 126-diversion hose; 127-fixed conductive sliding contact piece; 128-movable conductive sliding contact piece; 129-transmission belt. DETAILED DESCRIPTION

[0021] The following is combined with Figure 1-Figure 7 , and further illustrate the technical solution of the present invention through specific implementation methods.

[0022] The present invention provides a rapid detection device for the change of electrical properties when a cable is heated, comprising a cross-sectional plate 102, at least two connecting and fixing frames 120 are fixedly installed between the two cross-sectional plates 102, two parallel screw rods 112 are slidably installed on each connecting and fixing frame 120, the screw rods 112 are arranged along the radial direction of the cross-sectional plate 102, the two parallel screw rods 112 are fixedly connected to a cross beam 113, an insulating rubber layer 108 is fixed on the cross beam 113, an electrical property detection conductive sealing tube 105 is coaxially arranged inside the insulating rubber layer 108; the electrical property detection conductive sealing tube 105 is provided with a concave The lower groove is conductively embedded with an inserted conductive column 111, and the outer surface of the insulating rubber layer 108 is pasted with an insulating detection patch plate 110. The insulating detection patch plate 110 is insulated from the inserted conductive column 111 through the insulating rubber layer 108, and the insulating detection patch plate 110 and the inserted conductive column 111 are electrically connected through a wire; a shell 101 is also fixed between the two cross-sectional plates 102, and the shell 101 is arranged on the outside of all insulating rubber layers 108, and the shell 101 is also equipped with a first injection port 103 and a second injection port 104 for injecting insulating rubber into the shell 101. A DC power supply and a current detection unit are arranged in series on the wire connecting the insulating detection patch plate 110 and the inserted conductive column 111, which are used to detect the insulation performance of the insulating rubber layer 108. A nut gear bracket 124 is also fixedly mounted on each connecting and fixing frame 120. A gap is provided between the nut gear bracket 124 and the connecting and fixing frame 120. Two nut gears 122 are provided in the gap. The two nut gears 122 are respectively threadedly sleeved on the corresponding screw rods 112. At the same time, the two nut gears 122 are also connected by a transmission belt 129. All the nut gears 122 are meshed and transmitted through a synchronous gear ring 121 that is rotationally matched with all the connecting and fixing frames 120. An adjusting gear 123 is meshed and transmitted on one of the nut gears 122. The adjusting gear 123 is rotationally matched with the nut gear bracket 124. An adjusting rod shaft 125 is coaxially fixed on the adjusting gear 123. The adjusting rod shaft 125 extends to the outside of the housing 101, and a hexagonal prism groove is provided at one end of the adjusting rod shaft 125 located outside the housing 101.

[0023] The cross-sectional plate 102 is embedded with the same number of fixed conductive sliding contact pieces 127 as the connecting fixed frame 120, and each fixed conductive sliding contact piece 127 is slidably provided with a movable conductive sliding contact piece 128 along the radial direction of the cross-sectional plate 102, and the movable conductive sliding contact piece 128 is conductively provided with the fixed conductive sliding contact piece 127, and the fixed conductive sliding contact piece 127 is insulated from the cross-sectional plate 102, wherein the movable conductive sliding contact piece 128 is conductively fixedly matched with the conductive sealing tube 105 for electrical performance detection. The conductive sealing tube 105 for electrical performance detection is hollow inside, and an annular spoiler 106 and a disc spoiler 107 are equidistantly arranged in the space inside the conductive sealing tube 105 for electrical performance detection, and the annular spoiler 106 and the disc spoiler 107 are used to slow down the flow of insulating liquid inside the conductive sealing tube 105 for electrical performance detection. Both ends of the electrical performance detection conductive sealing tube 105 are provided with drainage ports 109 connected to the inside of the electrical performance detection conductive sealing tube 105, and the drainage ports 109 extend to the outside of the insulating rubber layer 108; a liquid discharge pipe 119 and a liquid flow pump 117 are fixedly installed on each connection fixing frame 120, wherein the liquid discharge pipe 119 is connected to one of the drainage ports 109 through a guide hose 126, and the other drainage port 109 is connected to the water inlet of the liquid flow pump 117 through a liquid input pipe 118 and a guide hose 126, and the drainage port of the liquid flow pump 117 is fixedly connected to the drainage intermediate pipe 116. A closed-loop detection pipe 114 is fixedly connected between the drainage intermediate pipe 116 and the liquid discharge pipe 119, and a closed-loop resistor 115 is arranged inside the closed-loop detection pipe 114.

[0024] The working principle of the rapid detection device for the change of electrical properties of a cable when it is heated is as follows: the whole is connected in series in the cable to be detected, and a corresponding number of electrical property detection conductive sealing tubes 105 are selected according to the number of cable cores (the cross-sectional area of ​​the electrical property detection conductive sealing tubes 105 should be consistent with the cross-sectional area of ​​the cable core to be detected), and an insulating rubber layer 108 with the same material and thickness as the insulation layer of the cable core is selected. Then rotate the adjusting rod shaft 125, the adjusting rod shaft 125 drives the adjusting gear 123 to rotate, the adjusting gear 123 drives one of the nut gears 122 to rotate, and then drives all the nut gears 122 to rotate synchronously through the synchronous gear ring 121 and the transmission belt 129. The rotation of the nut gear 122 will drive the screw rod 112 to move along its own axial direction (radial direction of the cross-sectional plate 102), and then control and adjust the spacing between all the insulating rubber layers 108 so that the spacing of the insulating rubber layers 108 is adjusted to be consistent with the spacing of the cable cores, and inject rubber of the same material as the outer insulation layer of the cable into the outer casing 101 through the first injection port 103 and the second injection port 104, wait for cooling and solidification, do not inject rubber into the first injection port 103 and the second injection port 104 at the same time, leaving one for exhaust.

[0025] During operation, a high voltage direct current (at least 500V or more, selected according to the material and thickness of the insulating rubber layer 108) is applied to the insulating detection patch plate 110 and the inserted conductive column 111, and then the current detection unit detects the current between the insulating detection patch plate 110 and the inserted conductive column 111, so as to judge the insulation performance of the insulating rubber layer 108. This is because when the cable is under high load, the temperature of the battery cell will rise, which will cause the insulating rubber layer 108 to soften or even melt and burn, which will cause contact between adjacent batteries and cause the risk of short circuit. Therefore, the insulation performance between two adjacent batteries is detected by measuring the insulation performance of the insulating rubber layer 108 in a single battery cell. When the insulation performance decreases, an early warning alarm is issued, and the load of the cable is reduced or the power is cut off in advance. At the same time, a current detection unit is connected in series on each cable to detect the resistance of the battery cell when it is heated in real time. When the resistance increases, it proves that the battery cell is heating up, and the insulation performance of the insulating rubber layer 108 of each battery cell can also be predicted and judged. Improve the redundancy of the insulation detection of the insulating rubber layer 108.

[0026] The liquid flow pump 117 is connected in series to a DC power supply, and an NPN transistor is also connected in series to the DC power supply, the collector of the NPN transistor is connected to the positive electrode of the DC power supply, and the emitter of the NPN transistor is connected to the negative electrode of the DC power supply, wherein the liquid flow pump 117 is arranged between the emitter of the NPN transistor and the negative electrode of the DC power supply. The closed-loop resistor 115 and a fixed resistor R2 are connected in series to another DC power supply, and a fixed resistor R1 is connected in series between the positive terminal of the closed-loop resistor 115 and the base of the NPN transistor, and the negative terminal of the closed-loop resistor 115 is directly electrically connected to the emitter of the NPN transistor.When the cable is working under high load, the temperature of the battery core will continue to rise, and then the temperature of the electrical performance detection conductive sealing tube 105 will rise. At this time, the insulating liquid inside the electrical performance detection conductive sealing tube 105 will transfer the temperature to the closed-loop detection tube 114. This is because, driven by the liquid flow pump 117, the insulating liquid will pass through the liquid flow pump 117, the discharge intermediate tube 116, the closed-loop detection tube 114, the liquid discharge pipe 119, the guide hose 126, the discharge port 109, the electrical performance detection conductive sealing tube 105, the annular baffle 106 and the disc baffle 107, the discharge port 109, the guide hose 126, and then flow back to the liquid flow pump 117 through the liquid input pipe 118 In this process, the closed-loop resistor 115 in the closed-loop detection tube 114 will be heated by the insulating liquid, which will cause the resistance of the closed-loop resistor 115 to increase. Therefore, the potential difference between the two ends of the closed-loop resistor 115 increases. At this time, the forward bias voltage between the base and the emitter of the NPN transistor increases, so the current that can pass through the collector and the emitter of the NPN transistor will increase, and the speed of the liquid flow pump 117 will increase, thereby driving more insulating liquid to enter and flow in the electrical performance detection conductive sealing tube 105. If the resistance of the closed-loop resistor 115 is still increasing (which directly reflects that the speed of the impeller inside the liquid flow pump 117 is still increasing), it means that the working temperature of the battery cell is rising rapidly. The temperature state, that is, the load of the cable is increasing rapidly. This is because the insulating liquid inside the electrical performance detection conductive sealing tube 105 is in direct contact with the electrical performance detection conductive sealing tube 105. Therefore, the temperature of the insulating liquid inside the electrical performance detection conductive sealing tube 105 is higher than that in the closed-loop detection tube 114. The insulating liquid inside the electrical performance detection conductive sealing tube 105 can be sent to the closed-loop detection tube 114 for detection by driving the insulating liquid to circulate at a low speed through the liquid flow pump 117. When the temperature of the insulating liquid exceeds the standard, it means that the temperature of the electrical performance detection conductive sealing tube 105 and the battery core is rising. Since the resistance value of the closed-loop resistor 115 increases, the liquid flow pump 117 drives the insulating liquid to flow. The flow rate of the liquid is increased, thereby reducing the heat exchange time between the insulating liquid and the conductive sealing tube 105 for detecting electrical properties. If the resistance of the closed-loop resistor 115 is still increasing at this time, it means that the load of the battery cell is in a state of rapid increase, which can be achieved by detecting the power of the liquid flow pump 117. If the power of the liquid flow pump 117 is in a state of continuous increase, an alarm can be issued (by accelerating the circulation of the insulating liquid to reduce the heat exchange time, it is determined whether the load of the cable is in an increasing state. If the resistance of the closed-loop resistor 115 is reduced, the corresponding power of the liquid flow pump 117 is reduced, which can be ignored at this time), and the cable is cut off or the load of the cable is reduced to prevent the insulating rubber layer 108 from melting and breaking due to high temperature.

Claims

1. A rapid detection device for changes in electrical properties of a cable when it is heated, characterized in that: It comprises a cross-sectional plate (102), at least two connecting and fixing frames (120) are fixedly installed between the two cross-sectional plates (102), two parallel screw rods (112) are slidably installed on each connecting and fixing frame (120), the screw rods (112) are arranged along the radial direction of the cross-sectional plate (102), the two parallel screw rods (112) are fixedly connected to a cross beam (113), an insulating rubber layer (108) is fixed on the cross beam (113), and an electrical performance detection conductive sealing tube (105) is coaxially arranged inside the insulating rubber layer (108); The electrical performance detection conductive sealing tube (105) is provided with a lower groove, in which an inserted conductive column (111) is conductively embedded, and an insulation detection application plate (110) is attached to the outer surface of the insulation rubber layer (108), the insulation detection application plate (110) is insulated from the inserted conductive column (111) by the insulation rubber layer (108), and the insulation detection application plate (110) and the inserted conductive column (111) are electrically connected via a wire; A shell (101) is also fixed between the two cross-sectional plates (102), the shell (101) is arranged outside all the insulating rubber layers (108), and the shell (101) is also provided with a first injection port (103) and a second injection port (104) for injecting the insulating rubber into the shell (101); A DC power supply and a current detection unit are arranged in series on the wire connected between the insulation detection application plate (110) and the inserted conductive column (111), and are used to detect the insulation performance of the insulation rubber layer (108); The cross-sectional plate (102) is embedded with fixed conductive sliding contact pieces (127) of the same number as the connecting fixed frame (120), and each fixed conductive sliding contact piece (127) is provided with a movable conductive sliding contact piece (128) slidingly arranged along the radial direction of the cross-sectional plate (102), the movable conductive sliding contact piece (128) and the fixed conductive sliding contact piece (127) are conductively arranged, and the fixed conductive sliding contact piece (127) and the cross-sectional plate (102) are insulated, wherein the movable conductive sliding contact piece (128) is conductively fixedly matched with the conductive sealing tube (105) for detecting electrical properties.

2. A rapid detection device for changes in electrical properties of a cable when it is heated according to claim 1, characterized in that: A nut gear bracket (124) is also fixedly mounted on each connecting and fixing frame (120); a gap is provided between the nut gear bracket (124) and the connecting and fixing frame (120); two nut gears (122) are provided in the gap; the two nut gears (122) are respectively threadedly sleeved on corresponding screw rods (112); and the two nut gears (122) are also connected in transmission via a transmission belt (129).

3. A rapid detection device for changes in electrical properties of a cable when it is heated according to claim 2, characterized in that: All the nut gears (122) are meshed with each other through a synchronous gear ring (121) that is rotatably matched with all the connection fixing frames (120), and an adjustment gear (123) is provided on one of the nut gears (122) for meshing transmission. The adjustment gear (123) is rotatably matched with a nut gear bracket (124), and an adjustment rod shaft (125) is coaxially fixed on the adjustment gear (123). The adjustment rod shaft (125) extends to the outside of the housing (101), and a hexagonal prism groove is provided on one end of the adjustment rod shaft (125) located outside the housing (101).

4. A rapid detection device for changes in electrical properties of a cable when it is heated according to claim 3, characterized in that: The interior of the electrical performance detection conductive sealing tube (105) is hollow, and an annular baffle plate (106) and a disc baffle plate (107) are arranged in a space crosswise and equidistantly inside the electrical performance detection conductive sealing tube (105). The annular baffle plate (106) and the disc baffle plate (107) are used to slow down the flow of insulating liquid inside the electrical performance detection conductive sealing tube (105).

5. A rapid detection device for changes in electrical properties of a cable when it is heated according to claim 4, characterized in that: Both ends of the electrical property detection conductive sealing tube (105) are provided with drainage ports (109) that are in communication with the interior of the electrical property detection conductive sealing tube (105), and the drainage ports (109) extend to the outside of the insulating rubber layer (108); a liquid discharge pipe (119) and a liquid flow pump (117) are fixedly mounted on each connection fixing frame (120), wherein the liquid discharge pipe (119) is in communication with one of the drainage ports (109) via a guiding hose (126), and the other drainage port (109) is in communication with the water inlet of the liquid flow pump (117) via a liquid input pipe (118) and a guiding hose (126), and the drainage port of the liquid flow pump (117) is fixedly connected with a drainage intermediate pipe (116).

6. A rapid detection device for changes in electrical properties of a cable when it is heated according to claim 5, characterized in that: A closed-loop detection tube (114) is fixedly connected between the discharge intermediate tube (116) and the liquid discharge tube (119), and a closed-loop resistor sheet (115) is disposed inside the closed-loop detection tube (114).

7. A method for quickly detecting changes in electrical properties of a cable when it is heated, characterized in that: The rapid detection device for the change of electrical properties of a cable when it is heated as described in claim 6 comprises the following steps: S1. According to the number of cable cores to be tested, a corresponding number of electrical performance testing conductive sealing tubes (105) are selected to ensure that their cross-sectional areas match the cross-sectional areas of the cable cores; Select an insulating rubber layer (108) with the same material and thickness as the cable core insulation layer to provide consistency material guarantee for subsequent testing; S2, installing the electrical performance detection conductive sealing tube (105) in series into the target cable; S3, by rotating the adjusting rod shaft (125), driving the adjusting gear (123) and the synchronous gear ring (121), so that all the nut gears (122) rotate synchronously, adjusting the radial movement of the screw rod (112) in the cross-sectional plate (102), and accurately controlling the spacing of the insulating rubber layer (108) to be consistent with the spacing of the cable cores; S4, using the first injection port (103) and the second injection port (104), gradually injecting rubber into the housing (101), with the material being consistent with the outer insulation layer of the cable; S5, detecting the loop current from the application plate (110) to the conductive column (111) through a current detection unit, and evaluating the insulation performance of the insulating rubber layer (108); S6. According to the change in the resistance value of the closed-loop resistor (115), the rotation speed of the liquid flow pump (117) is adjusted, and the load condition of the cable is determined by detecting the change in the power of the liquid flow pump (117), so as to avoid softening or melting of the insulating rubber layer (108) due to high temperature.

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