A power cable detection device for electrical construction
By designing a limiting, detection, and marking mechanism that works in synergy, and utilizing magnetic powder suspension and electromagnet marking, efficient and accurate detection and marking of cable insulation layers are achieved. This solves the problems of low detection efficiency and insufficient accuracy in existing technologies and is suitable for cable inspection in power construction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HUNAN XIANGNENG HAOMING CONSTRUCTION CO LTD
- Filing Date
- 2026-03-04
- Publication Date
- 2026-06-12
AI Technical Summary
Existing cable testing equipment is difficult to accurately locate minor localized damage to the cable insulation layer during operation, and has low testing efficiency and high cost, making it impossible to achieve comprehensive testing of long-distance cables.
Design a power cable testing device, including a limiting mechanism, a testing mechanism, a marking mechanism and a driving mechanism. Through the cooperation of a ring-shaped conductive brush and an electromagnet, the device can automatically detect and mark the location of insulation layer damage during continuous cable movement, and utilize magnetic powder suspension spraying and magnetic field marking.
It enables efficient and accurate detection and marking of cable insulation, avoids blind spots in detection, significantly improves the detection rate of minute defects, enhances detection efficiency and accuracy, adapts to different cable diameters, and ensures stable operation of the equipment.
Smart Images
Figure CN122193792A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of cross-linked polyethylene insulated power cable testing technology, specifically a power cable testing device for power construction. Background Technology
[0002] In the field of power construction and operation and maintenance, the integrity of the insulation layer of cross-linked polyethylene insulated power cables is crucial to ensuring power supply safety and preventing short circuits, leakage, and even fires. Therefore, efficient and accurate detection and positioning of cable insulation layers has always been a core technical requirement in the industry. Currently, common cable insulation testing methods mainly include offline withstand voltage testing (such as spark testers), insulation resistance measurement, and online monitoring based on the principle of partial discharge.
[0003] However, existing technologies have many limitations: First, offline testing methods, such as spark testing, typically require the cable to be stopped and tested in sections, resulting in low testing efficiency and an inability to assess the real-time condition of cables in operation. Second, while traditional insulation resistance measurements or underwater testing methods can determine the overall insulation degradation, they struggle to accurately locate minor localized damage (such as pinholes or scratches) on the insulation surface. Third, manual inspections or point-by-point testing with handheld devices are not only time-consuming and labor-intensive, reliant on personnel experience, but also carry the risk of missed detections, especially for long-distance cables where comprehensive testing is prohibitively expensive. Existing cable testing devices, such as the construction site cable testing device disclosed in CN111025192B, belong to the field of cable testing technology. They include a cable, a dielectric tank, and a resistance testing component. The dielectric tank contains a conductive medium, and a tank cover is hinged to the top opening of the dielectric tank. The cable is placed in the conductive medium, with both ends passing through the tank cover. The resistance testing component includes a power supply, a switch, a first port, a second port, a testing port, and a buzzer. The first port is electrically connected to a first testing head, and the second port is electrically connected to a second testing head. The tank cover has holes for the testing heads to pass through. The testing port is connected to one end of the cable. When the first and second testing heads are passed through the tank cover and inserted into the conductive medium, the switch is turned on, the buzzer sounds an alarm, indicating normal operation. When the switch is turned off, the second testing head is removed from the dielectric tank, the cable is connected to the testing port, the switch is turned on, the buzzer sounds an alarm, indicating that the cable insulation layer is damaged. If the buzzer does not sound an alarm, it indicates that the cable insulation layer is intact. However, in actual use, although it can roughly determine the extent of insulation damage, it cannot mark the location of the damage, making it difficult to accurately determine the location of the damage (especially small cracks). Summary of the Invention
[0004] The purpose of this invention is to provide a power cable testing device for power construction, so as to solve the problems mentioned in the background art.
[0005] To achieve the above objectives, the present invention provides the following technical solution: a power cable testing device for power construction, comprising a workbench, wherein limiting mechanisms are symmetrically installed on the workbench, and the limiting mechanisms are used to guide and limit the cable body; a fixing frame is also fixed on the workbench, and the fixing frame is located between the two limiting mechanisms. The testing mechanism is used to test the insulation layer on the surface of the cable body, and the testing mechanism is installed on the workbench. A marking mechanism is used to accurately mark the location of damage to the insulation layer on the surface of the cable body. The marking mechanism is installed on the workbench. A drive mechanism is used to drive the marking mechanism and the detection mechanism to move in order to achieve comprehensive detection and marking of the insulation layer on the surface of the cable body. The drive mechanism is mounted on the workbench.
[0006] Preferably, the limiting mechanism includes mounting frames that are symmetrically fixed on the worktable, and two guide rollers are provided on the lower side of the mounting frames. The center of the guide rollers is a concave structure. The guide rollers can guide and limit the cable body, ensuring the stability of the cable body's movement.
[0007] Preferably, the guide roller is symmetrically connected with connecting blocks at the front and rear via bearings, and the connecting block on one side of the guide roller is threadedly connected to the bidirectional threaded rod on the mounting frame connected to the bearing, while the connecting block on the other side of the guide roller is slidably connected to the vertical rod fixed on the mounting frame. The threaded connection between the connecting block and the bidirectional threaded rod provides a basic guarantee for adjusting the distance between the two guide rollers, and the sliding guide between the connecting block and the vertical rod ensures the stability of the guide roller movement.
[0008] Preferably, the detection mechanism includes a fixed plate with one end fixed to a fixed frame, and the other end of the fixed plate fixed to a fixed ring. The fixed ring and a slip ring with a "T" shaped cross-section are slidably connected, and the slip ring and the toothed ring are fixed to each other. The sliding action between the slip ring and the fixed ring can ensure the stability of the toothed ring rotation.
[0009] Preferably, the toothed ring is fixed to one end of the insulating rod, and the other end of the insulating rod is fixed to the annular conductive brush. The annular conductive brush is electrically connected to the current detector. At the same time, the current detector is fixed to the insulating ring plate. The insulating ring plate is sleeved around the outside of the annular conductive brush, and the insulating ring plate is fixed to the toothed ring. With the above structure, a basic guarantee can be provided for realizing leakage current detection on the surface of the cable body, thereby determining whether there is damage to the insulation layer on the surface of the cable body.
[0010] Preferably, the toothed ring meshes with the convex rack to achieve a transmission effect, and the convex rack is symmetrically fixed with sliding rods at the front and back, and the sliding rods are slidably connected to the fixed frame. At the same time, a round rod is fixed to the lower end face of the convex rack, and the round rod is slidably connected to the inclined groove. The inclined groove is opened on the horizontal plate. By moving the horizontal plate, combined with the sliding action between the inclined groove and the round rod, a basic force can be provided for the movement of the convex rack. Combined with the transmission action between the convex rack and the toothed ring, a basic force can be provided for the rotation of the annular conductive brush. When the convex rack moves, the sliding guidance action between the sliding rod and the fixed frame can ensure the stability of the movement of the convex rack.
[0011] Preferably, the marking mechanism includes a storage box fixed to the horizontal plate, and sliders are symmetrically fixed to the front and back of the lower end of the storage box. The sliders are slidably connected to the guide rails, and the guide rails are symmetrically fixed to the worktable. When the storage box moves, the sliding guidance between the sliders and the guide rails can ensure that the storage box makes stable linear motion.
[0012] Preferably, a delivery pump is installed on the storage tank, and the delivery pump is connected to the circular pipe through a conduit. The circular pipe is fixed on the storage tank, and a flow guide ring is fixed at the upper end of the circular pipe. Nozzles are distributed at equal angles on the inner side of the flow guide ring. Through the above structure, the delivery and spraying of magnetic powder suspension can be realized, thereby providing a basic guarantee for subsequent marking of the damaged location of the insulation layer on the surface of the cable body.
[0013] Preferably, the storage box is also fixed with a mounting ring located to the right of the current guiding ring on the right side of the annular conductive brush, and an electromagnet is installed inside the mounting ring. An annular aluminum plate with an arc-shaped cross-section is fixed to the side of the electromagnet. The annular aluminum plate and the mounting ring are fixed to each other. Through the action of the electromagnet, the magnetic powder suspension can be gathered at the damaged position of the insulation layer on the surface of the cable body, thereby achieving the marking function.
[0014] Preferably, the driving mechanism includes a vertical plate fixed to the worktable, a motor fixed to the vertical plate, a disc fixed to the output end of the motor, and a convex shaft fixed to the disc. The convex shaft is slidably connected to a sliding plate, and the sliding plate is fixed to the storage box. The motor drives the disc and the convex shaft to rotate, and the sliding action between the convex shaft and the sliding plate provides a basic force for the left and right reciprocating motion of the storage box, thereby ensuring the normal operation of the device.
[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This power cable inspection device for power construction, through the coordinated design of the drive mechanism, inspection mechanism, and marking mechanism, enables automatic comprehensive inspection of the insulation layer of the cable during continuous passage. Upon detection of damage, it automatically triggers the spraying of magnetic powder suspension and magnetic field marking. The entire process requires no manual intervention, achieving a highly efficient operation mode of immediate location and marking after inspection, greatly improving the efficiency of long cable inspection. 2. This power cable inspection device for power construction combines the rotational motion of the annular conductive brush with the reciprocating motion of the storage box (carrying the nozzle and electromagnet), so that the annular conductive brush forms a composite spiral scanning trajectory relative to the moving cable, thereby ensuring 100% coverage inspection of the entire outer circumference insulation layer of the cable, effectively avoiding blind spots in inspection, and significantly improving the detection rate of minute defects. 3. The power cable testing device for power construction has a limiting mechanism that adjusts the guide roller spacing through a bidirectional threaded rod, which can quickly adapt to cables of different diameters and automatically ensure that the cable axis is aligned with the center of the annular conductive brush and electromagnet, thus ensuring the reference accuracy of testing and marking. The marking mechanism utilizes the principle of enhanced magnetic field in the leakage current area generated by the insulation damage point, so that the magnetic powder is accurately gathered at the damage point under the action of the electromagnet, forming a clear mark that is visible to the naked eye. 4. The power cable testing device used in power construction has an arc-shaped aluminum plate in the marking mechanism, which is fixed to the outside of the electromagnet. As a non-magnetic material, the aluminum plate can effectively prevent the magnetic powder suspension from being directly adsorbed on the electromagnet body, avoiding the magnetic field weakening, equipment overheating or even short circuit faults caused by magnetic powder accumulation, and ensuring the long-term stable operation of the electromagnet. Attached Figure Description
[0016] Figure 1 This is a frontal three-dimensional structural diagram of the device of the present invention; Figure 2 This is a side view of the overall three-dimensional structure of the device of the present invention; Figure 3 This is a frontal cross-sectional three-dimensional structural diagram of the limiting mechanism of the present invention; Figure 4 This is a side view of the three-dimensional structure of the fixing frame of the present invention; Figure 5 This is a cross-sectional three-dimensional structural diagram of the detection mechanism of the present invention; Figure 6 This is a three-dimensional structural diagram of the marking mechanism and the driving mechanism of the present invention; Figure 7 This is a three-dimensional cross-sectional view of the mounting ring of the present invention.
[0017] In the diagram: 1. Workbench; 2. Limiting mechanism; 201. Mounting frame; 202. Guide roller; 203. Connecting block; 204. Bidirectional threaded rod; 205. Vertical rod; 3. Cable body; 4. Fixing frame; 5. Detection mechanism; 501. Fixing plate; 502. Fixing ring; 503. Slip ring; 504. Toothed ring; 505. Insulating rod; 506. Annular conductive brush; 507. Current detector; 508. Insulating ring plate; 509. Raised toothed rack; 5 10. Slide bar; 511. Round bar; 512. Inclined groove; 513. Horizontal plate; 6. Marking mechanism; 601. Storage box; 602. Slider; 603. Guide rail; 604. Conveying pump; 605. Round pipe; 606. Guide ring; 607. Nozzle; 608. Mounting ring; 609. Electromagnet; 610. Annular aluminum plate; 7. Drive mechanism; 701. Vertical plate; 702. Motor; 703. Disc; 704. Convex shaft; 705. Slide plate. Detailed Implementation
[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0019] Please see Figures 1-7 The present invention provides a technical solution: a power cable testing device for power construction, including a workbench 1, on which limit mechanisms 2 are symmetrically installed, and the limit mechanisms 2 are used to guide and limit the cable body 3. A fixing frame 4 is also fixed on the workbench 1, and the fixing frame 4 is located between the two limit mechanisms 2. The testing mechanism 5 is used to test the insulation layer on the surface of the cable body 3. The testing mechanism 5 is installed on the workbench 1. The marking mechanism 6 is used to accurately mark the location of the insulation layer damage on the surface of the cable body 3. The marking mechanism 6 is installed on the workbench 1. The drive mechanism 7 is used to drive the marking mechanism 6 and the detection mechanism 5 to move so as to realize the comprehensive detection and marking of the insulation layer on the surface of the cable body 3. The drive mechanism 7 is installed on the workbench 1.
[0020] The limiting mechanism 2 includes a mounting frame 201 that is symmetrically fixed on the worktable 1. Two guide rollers 202 are provided on the lower side of the mounting frame 201, and the center of the guide rollers 202 is a concave structure. Connecting blocks 203 are symmetrically connected to the guide rollers 202 through bearings. The connecting block 203 on one side of the guide roller 202 is threadedly connected to the bidirectional threaded rod 204 connected to the bearing on the mounting frame 201. The connecting block 203 on the other side of the guide roller 202 is slidably connected to the vertical rod 205 fixed on the mounting frame 201. When using this power cable testing device for power construction, such as Figures 1-7 As shown, firstly, by rotating the bidirectional threaded rod 204, the distance between the upper and lower guide rollers 202 is increased due to the threaded connection between the bidirectional threaded rod 204 and the connecting block 203 and the sliding action between the connecting block 203 and the vertical rod 205. Then, the cable body 3 passes through the gap between the upper and lower guide rollers 202 on the left side, and passes through the annular conductive brush 506, the current guide ring 606 and the electromagnet 609. Finally, the cable body 3 passes through the gap between the upper and lower guide rollers 202 on the right side and connects with the cable take-up device. After installation, by rotating the bidirectional threaded rod 204 in the opposite direction, according to the above principle, the distance between the upper and lower guide rollers 202 is reduced until the guide rollers 202 contact the cable body 3. At this time, the center of the cable body 3 is on the same horizontal line as the center of the annular conductive brush 506, the current guide ring 606 and the electromagnet 609, thus completing the initial preparation work. The detection mechanism 5 includes a fixing plate 501 with one end fixed to the fixing frame 4, and the other end of the fixing plate 501 fixed to the fixing ring 502. The fixing ring 502 is slidably connected to a slip ring 503 with a "T"-shaped cross-section, and the slip ring 503 is fixed to a toothed ring 504. The toothed ring 504 is fixed to one end of an insulating rod 505, and the other end of the insulating rod 505 is fixed to an annular conductive brush 506. The annular conductive brush 506 is electrically connected to a current detector 507. The current detector 507 is fixed to an insulating ring plate 508, which is sleeved around the outside of the annular conductive brush 506. The insulating ring plate 508 is fixed to the toothed ring 504. The toothed ring 504 meshes with a convex rack 509 to achieve a transmission effect. Slide rods 510 are symmetrically fixed on the convex rack 509. The slide bar 510 is slidably connected to the fixed frame 4. At the same time, a round rod 511 is fixed to the lower end face of the toothed rack 509. The round rod 511 is slidably connected to the inclined groove 512. The inclined groove 512 is opened on the horizontal plate 513. The marking mechanism 6 includes a storage box 601 fixed to the horizontal plate 513. The lower end face of the storage box 601 is symmetrically fixed with sliders 602. The sliders 602 are slidably connected to the guide rail 603. The guide rail 603 is symmetrically fixed to the worktable 1. The driving mechanism 7 includes a vertical plate 701 fixed to the worktable 1. A motor 702 is fixed on the vertical plate 701. A disc 703 is fixed to the output end of the motor 702. A convex shaft 704 is fixed on the disc 703. The convex shaft 704 is slidably connected to the sliding plate 705. The sliding plate 705 is fixed to the storage box 601. During testing, a low-voltage DC current is supplied to the cable body 3, and the cable take-up device moves the cable body 3 from left to right. Figures 1-7As shown, when the cable body 3 moves from left to right, the motor 702 is started synchronously. The motor 702 drives the disc 703 and the convex shaft 704 to rotate. Combined with the sliding action between the convex shaft 704 and the slide plate 705, the storage box 601 can move left and right in an orderly manner under force. Combined with the sliding guidance action between the slider 602 and the guide rail 603, the stability of the storage box 601's movement is ensured. While the storage box 601 moves left and right in an orderly manner, the horizontal plate 513 is driven to move left and right in an orderly manner. Combined with the sliding action between the inclined groove 512 and the round rod 511, the convex rack 509 can move back and forth in an orderly manner under force. Combined with the sliding guidance action between the slide rod 510 and the fixed frame 4, the stability of the convex rack 509's movement is ensured. When the rack 509 reciprocates, the meshing transmission between the convex rack 509 and the toothed ring 504 enables the toothed ring 504 to rotate in an orderly manner. The sliding action between the slip ring 503 and the fixed ring 502 ensures the stability of the rotation of the toothed ring 504. When the toothed ring 504 rotates, it synchronously drives the annular conductive brush 506 to rotate. The annular conductive brush 506 can perform a comprehensive inspection of the insulation layer on the surface of the cable body 3. If the insulation layer on the surface of the cable body 3 is intact, the current detector 507 cannot detect the current. If the insulation layer on the surface of the cable body 3 is damaged, the annular conductive brush 506 will contact the internal conductor of the cable body 3, thereby enabling the current detector 507 to detect the current, thus realizing the detection function of the insulation layer of the cable body 3. A delivery pump 604 is installed on the storage tank 601, and the delivery pump 604 is connected to the circular pipe 605 through a conduit. The circular pipe 605 is fixed on the storage tank 601. At the same time, a flow guide ring 606 is fixed at the upper end of the circular pipe 605. Nozzles 607 are distributed at equal angles on the inner side of the flow guide ring 606. A mounting ring 608 is also fixed on the storage tank 601, which is located on the right side of the flow guide ring 606 to the right of the annular conductive brush 506. An electromagnet 609 is installed in the mounting ring 608, and an annular aluminum plate 610 with an arc-shaped cross section is fixed on the side of the electromagnet 609. The annular aluminum plate 610 and the mounting ring 608 are fixed to each other. During the detection process, when the current detector 507 can detect the current, the controller starts the delivery pump 604 and the electromagnet 609. The delivery pump 604 delivers the magnetic powder suspension stored in the storage tank 601 to the circular tube 605, and then enters the guide ring 606 through the circular tube 605. Subsequently, it is evenly sprayed onto the surface of the cable body 3 through the nozzle 607. With the left and right reciprocating motion of the storage tank 601, the nozzle 607 can move left and right relative to the cable body 3, thereby ensuring that the magnetic powder suspension is evenly covered on the surface of the damaged area of the insulation layer of the cable body 3. As the cable body 3 carrying the magnetic powder suspension continues to move to the right, when the cable body 3 carrying the magnetic powder suspension moves to cooperate with the electromagnet 609, the electromagnet 609 generates a ring magnetic field, which can pull the magnetic powder suspension on the surface of the insulation layer of the cable body 3. Due to the leakage current at the damaged area of the insulation layer of the cable body 3, the magnetic field at the damaged area is stronger, thereby causing the magnetic powder suspension to gather towards the damaged area of the insulation layer of the cable body 3, thus realizing the automatic marking function. During the marking process, the arc-shaped annular aluminum plate 610 effectively protects the electromagnet 609, preventing it from sticking to the magnetic powder suspension and affecting its normal operation, thus ensuring the service life of the device.
[0021] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0022] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only for the purpose of helping to understand the method and core ideas of the present invention. The above descriptions are only preferred embodiments of the present invention. It should be noted that due to the limitations of textual expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of the present invention.
Claims
1. A power cable testing device for power construction, comprising a workbench (1), characterized in that: The workbench (1) is symmetrically equipped with limiting mechanisms (2) on the left and right sides, and the limiting mechanisms (2) are used to guide and limit the cable body (3). The workbench (1) is also fixed with a fixing frame (4), and the fixing frame (4) is located between the two limiting mechanisms (2) on the left and right sides. The testing mechanism (5) is used to test the surface insulation layer of the cable body (3), and the testing mechanism (5) is installed on the workbench (1); The marking mechanism (6) is used to accurately mark the location of the insulation layer damage on the surface of the cable body (3). The marking mechanism (6) is installed on the workbench (1). A drive mechanism (7) is used to drive the marking mechanism (6) and the detection mechanism (5) to move in order to achieve comprehensive detection and marking of the insulation layer on the surface of the cable body (3). The drive mechanism (7) is mounted on the workbench (1).
2. The power cable testing device for power construction according to claim 1, characterized in that: The limiting mechanism (2) includes a mounting frame (201) that is symmetrically fixed on the worktable (1) and two guide rollers (202) are provided on the lower side of the mounting frame (201), and the center position of the guide rollers (202) is a concave structure.
3. The power cable testing device for power construction according to claim 2, characterized in that: The guide roller (202) is symmetrically connected with connecting blocks (203) via bearings. The connecting block (203) on one side of the guide roller (202) is threadedly connected to the bidirectional threaded rod (204) on the mounting frame (201) connected to the bearing. The connecting block (203) on the other side of the guide roller (202) is slidably connected to the vertical rod (205) fixed on the mounting frame (201).
4. The power cable testing device for power construction according to claim 1, characterized in that: The detection mechanism (5) includes a fixing plate (501) with one end fixed to the fixing frame (4), and the other end of the fixing plate (501) is fixed to the fixing ring (502). The fixing ring (502) is slidably connected to the sliding ring (503) with a "T" shaped cross section, and the sliding ring (503) is fixed to the toothed ring (504).
5. A power cable testing device for power construction according to claim 4, characterized in that: The toothed ring (504) is fixed to one end of the insulating rod (505), and the other end of the insulating rod (505) is fixed to the annular conductive brush (506). The annular conductive brush (506) is electrically connected to the current detector (507). At the same time, the current detector (507) is fixed to the insulating ring plate (508). The insulating ring plate (508) is wrapped around the outside of the annular conductive brush (506), and the insulating ring plate (508) is fixed to the toothed ring (504).
6. A power cable testing device for power construction according to claim 5, characterized in that: The gear ring (504) meshes with the convex rack (509) to achieve transmission. The convex rack (509) is symmetrically fixed with sliding rods (510) at the front and back. The sliding rods (510) are slidably connected to the fixed frame (4). At the same time, a round rod (511) is fixed on the lower end face of the convex rack (509). The round rod (511) is slidably connected to the inclined groove (512). The inclined groove (512) is opened on the horizontal plate (513).
7. A power cable testing device for power construction according to claim 6, characterized in that: The marking mechanism (6) includes a storage box (601) fixed to the horizontal plate (513), and a slider (602) is symmetrically fixed to the front and back of the lower end of the storage box (601). The slider (602) is slidably connected to the guide rail (603), and the guide rail (603) is symmetrically fixed to the worktable (1).
8. A power cable testing device for power construction according to claim 7, characterized in that: The storage tank (601) is equipped with a delivery pump (604), and the delivery pump (604) is connected to the circular pipe (605) through a conduit. The circular pipe (605) is fixed on the storage tank (601), and a flow guide ring (606) is fixed at the upper end of the circular pipe (605). Nozzles (607) are distributed at equal angles on the inner side of the flow guide ring (606).
9. A power cable testing device for power construction according to claim 8, characterized in that: The storage box (601) is also fixed with a mounting ring (608) on the right side of the current guide ring (606) located on the right side of the annular conductive brush (506), and an electromagnet (609) is installed inside the mounting ring (608). An annular aluminum plate (610) with an arc-shaped cross-section is fixed on the side of the electromagnet (609), and the annular aluminum plate (610) and the mounting ring (608) are fixed to each other.
10. A power cable testing device for power construction according to claim 9, characterized in that: The drive mechanism (7) includes a vertical plate (701) fixed on the workbench (1), and a motor (702) is fixed on the vertical plate (701). A disc (703) is fixed at the output end of the motor (702), and a convex shaft (704) is fixed on the disc (703). The convex shaft (704) is slidably connected to the slide plate (705), and the slide plate (705) is fixed on the storage box (601).