A set of switchgear fault discharge detection equipment and method

Abstract

The application discloses a complete switch cabinet fault discharge detection equipment and method, relates to the electric power equipment live detection technical field, and detects the equipment and includes the mobile base, the mobile base is hinged and installed with the turnover assembly, the rotating output end of the turnover assembly is fixedly installed with the right-angle frame, the right-angle frame is fixedly installed with the loading plate, the loading plate is fixedly installed with the inclination angle adjusting assembly, the movable output end of the inclination angle adjusting assembly is fixedly installed with the first driving cylinder, the piston rod end of the first driving cylinder is fixedly installed with the terminal angle plate, and the multi-mode partial discharge sensor is fixedly installed on the terminal angle plate. The application realizes the multi-posture accurate positioning of the sensor through the turnover and inclination angle adjusting assembly, eliminates the detection blind area of the top and bottom of the switch cabinet, adopts the multi-mode sensing fusion and signal conditioning architecture to improve the anti-interference ability and reduce the misjudgment rate, simultaneously combines the mechanical limiting and positioning and the cylinder distance adjusting mechanism to ensure the standardization of the detection data and further improves the reliability of the detection.

Description

Technical Field

[0001] This invention relates to the field of live-line testing technology for power equipment, and specifically discloses a complete set of switchgear fault discharge detection equipment and method. Background Technology

[0002] Complete switchgear sets, as core equipment in power systems for power generation, transmission, distribution, and energy conversion, are widely used in substations, industrial and mining enterprises, and high-rise buildings. Their manufacturing quality and installation process directly determine the safety and stability of the power supply system. During the factory testing and initial installation handover stages of the switchgear, minor defects may exist on the surface of insulating components, metal particles may be introduced during assembly, or installation stress may cause poor contact at connection points, easily leading to initial insulation defects. If these hidden dangers are not effectively detected before commissioning, under the high electric field of long-term operation, they can easily induce partial discharge, thereby accelerating insulation aging and even causing breakdown faults in the early stages of operation. Therefore, implementing high-precision fault discharge detection during the factory testing and initial installation stages is a crucial step in eliminating manufacturing defects and verifying installation quality.

[0003] Currently, non-invasive detection methods are mainly used for partial discharge detection in the factory testing and on-site acceptance testing of switchgear. Common existing technologies include: using portable ultrasonic detectors to collect ultrasonic signals from the cabinet surface through air coupling or contact probes; using transient ground voltage sensors close to the gaps in the metal casing of the cabinet to detect electromagnetic wave signals; and using ultra-high frequency sensors to detect through observation windows or insulating trays. In the factory process, the entire cabinet is usually tested for withstand voltage in a shielded room while monitoring discharge signals. During the installation phase, testing personnel often use handheld instruments to scan or measure point by point at the observation windows, instrument compartments, cable compartment gaps, etc. of the switchgear, and determine whether there is any discharge abnormality by reading the dB value or pulse waveform displayed by the instrument.

[0004] However, the aforementioned existing technologies still have the following significant drawbacks in practical applications during the factory and initial installation stages. First, the detection sensitivity is severely affected by environmental noise, resulting in a high false positive rate. Complex electromagnetic interference and mechanical vibration noise often exist in factory workshops or installation sites. Existing handheld detection equipment has limited anti-interference capabilities, especially in unshielded environments, where it is highly susceptible to misinterpreting environmental noise as a discharge signal, or missing weak early insulation defects due to noise masking, leading to false negative or false positive results and affecting the accuracy of factory-approved judgments.

[0005] Secondly, the inspection is highly location-dependent and has blind spots. The top of the switchgear is usually high off the ground, making it difficult for inspectors to raise the equipment to effectively cover gaps or insulators at the top. On the other hand, the bottom of the switchgear is often located in cable trenches or close to the ground, with obstructed visibility and limited operating space, making inspection of the cable entry and exit areas at the bottom extremely difficult. These blind spots caused by space constraints make it very easy to miss potential insulation defects at the top and bottom of the cabinet.

[0006] Finally, during the manufacturing and installation phases, it is often necessary to compare multiple devices horizontally or the same device vertically. Existing technologies mostly rely on manual handheld measurements, making it difficult to maintain constant distances, angles, and pressures between sensors and the cabinet. Furthermore, the lack of unified and precise standards results in large dispersion of test data, making it difficult to form traceable and standardized data. This hinders the establishment of a baseline status file for the initial operation of the equipment and creates difficulties for subsequent operation and maintenance analysis.

[0007] In summary, existing testing technologies have limitations in terms of anti-interference capabilities, testing coverage, and data standardization, which severely restrict the quality control level of complete switchgear during the factory and installation stages. These deficiencies not only make it difficult to detect some hidden insulation hazards in a timely manner, increasing the risk of equipment entering the network with defects, but also make the testing process overly reliant on manual experience and lack traceable quantitative benchmarks. Summary of the Invention

[0008] To address the current issues in switchgear manufacturing and initial installation testing, which are limited by external manual testing methods and physical constraints of enclosed spaces, resulting in significant blind spots at the top and bottom of the switchgear and a lack of standardized and consistent testing data, this invention provides a complete set of switchgear fault discharge detection equipment and methods.

[0009] To address the above problems, in a first aspect, the present invention provides the following technical solution: A complete set of switchgear fault discharge detection equipment includes a movable base platform. A flipping assembly is hinged to the movable base platform. A right-angle frame is fixedly mounted on the rotation output end of the flipping assembly. A carrier plate is fixedly mounted on the right-angle frame. A tilt adjustment assembly is fixedly mounted on the carrier plate. A first drive cylinder is fixedly mounted on the movable output end of the tilt adjustment assembly. A terminal corner plate is fixedly mounted on the piston rod end of the first drive cylinder. A multi-mode partial discharge sensor is fixedly mounted on the terminal corner plate. The tilt adjustment assembly is configured to drive the first drive cylinder, the terminal corner plate, and the multi-mode partial discharge sensor to rotate as a whole via the displacement of its movable output end, so as to switch and lock the multi-mode partial discharge sensor to any one of the following tilt detection postures: horizontal, 45° upward, and 45° downward. The first drive cylinder is configured to push the terminal corner plate to translate via the extension and retraction of its piston rod, so as to finely adjust the detection distance between the multi-mode partial discharge sensor and the test surface of the complete set of switchgear while maintaining the detection posture unchanged.

[0010] Preferably, the movable base has a through square groove, and the flipping assembly includes a second drive cylinder and a support. The second drive cylinder is hinged to the inner side of the square groove, and the support is fixedly connected to the movable base and arranged on the outer side of the square groove. A transversely arranged horizontal shaft is rotatably installed inside the support, and a T-shaped frame is fixedly connected to the outer wall of the horizontal shaft. The piston rod of the second drive cylinder is arranged upward and its end is fixedly connected to the bottom of the T-shaped frame. The top of the T-shaped frame is fixedly connected to the right-angle frame through a support rod.

[0011] Preferably, a vertically arranged fixed beam is fixedly installed on the side of the movable base, a partition beam is hinged to the top of the fixed beam, a support beam is provided between the partition beam and the fixed beam, and the two ends of the fixed beam are respectively hinged to the partition beam and the support beam. The fixed beam, the partition beam and the support beam together form a hinged triangular frame structure. An insulating plate is fixedly installed on the inner side of the partition beam, and the insulating plate is fastened to the right-angle frame.

[0012] Preferably, the tilt adjustment assembly includes two carrier seats that are fastened to the carrier plate. Adjustment frames are fastened to the sides of both carrier seats, and the first drive cylinder is arranged between the two adjustment frames. The adjustment frame is a C-shaped cantilever structure, and a guide groove is provided at the cantilever end of the adjustment frame. The guide groove is a right-angle groove structure. Pulleys are installed on both sides of the first drive cylinder, and the pulleys slide in cooperation with the inner wall of the guide groove.

[0013] Preferably, a third driving cylinder is provided on the carrier plate, the piston rod of the third driving cylinder is arranged upward, the cylinder body end of the third driving cylinder is hinged to the carrier plate, the piston rod end of the third driving cylinder is arranged between two adjusting brackets, and the piston rod end of the third driving cylinder is hinged to the cylinder body of the first driving cylinder.

[0014] Preferably, a housing is fixedly installed on the movable base. The housing has an opening on the side facing the multimodal partial discharge sensor. The interior of the housing is a component mounting area, in which a signal conditioning module and a data acquisition unit are integrated. The two sides of the housing are a panel and a door, respectively. The panel has a wire hole, and the door is equipped with a door lock handle for opening, closing, and locking.

[0015] Preferably, a vertical pole is fixedly installed on the side of the housing, and a slide is slidably fitted on the outer periphery of the vertical pole. A locking rod for locking the axial position of the slide is arranged between the slide and the vertical pole. A visual interactive terminal is fixedly installed on the slide, and the visual interactive terminal is configured to display discharge detection data and equipment operating status in real time. An audible and visual alarm is fixedly installed on the top of the housing, and the audible and visual alarm is configured to trigger a graded alarm when an abnormal discharge signal is detected.

[0016] Preferably, the bottom of the movable platform is equipped with multiple support feet, and each support foot is equipped with a caster wheel on its inner side; the support feet are configured to support the movable platform and keep it horizontal during the testing process, and the caster wheel is configured to carry the movable platform to achieve movement and turning during the transfer process; the bottom of the support feet is provided with an anti-slip pad to prevent the movable platform from shifting during the testing process.

[0017] On the other hand, the present invention also provides a method for detecting fault discharge in a complete set of switchgear, comprising the following steps: S1. Equipment positioning: Use casters to move the mobile platform to the designated testing position of the switchgear to be tested, unfold the support legs to keep the mobile platform level and lock it to prevent displacement during the testing process; S2. Coarse alignment: Start the flipping component to drive the right-angle frame to flip, and adjust the entire mounting plate and multi-mode partial discharge sensor to face the preset detection surface of the switchgear under test; S3, Attitude fine adjustment: Drive the tilt adjustment component to make its moving output end produce displacement, drive the first drive cylinder, the terminal corner plate and the multimodal partial discharge sensor to rotate as a whole, switch the multimodal partial discharge sensor to and lock it to one of the three detection attitudes that matches the surface to be measured: horizontal, 45° upward, and 45° downward. S4. Spacing fine adjustment: Control the extension and retraction of the piston rod of the first drive cylinder to push the terminal corner plate to move along the detection direction. Under the condition of maintaining the detection posture unchanged, adjust the detection spacing between the multimodal partial discharge sensor and the surface to be measured to the preset value. S5. Signal Acquisition: The multi-mode partial discharge sensor is activated to perform partial discharge detection on the complete switchgear. The multi-mode discharge signal acquired by the sensor is conditioned by the signal conditioning module inside the enclosure and then digitally acquired and stored by the data acquisition unit. S6. Status Monitoring and Alarms: The visual interactive terminal displays discharge detection data and equipment operating status in real time; when an abnormal discharge signal is detected, the audible and visual alarm triggers a tiered alarm.

[0018] Preferably, in step S5, the multi-modal partial discharge sensor synchronously acquires partial discharge signals of three modes: ultrasonic signal, transient ground voltage signal, and high-frequency current signal; after the signal conditioning module performs bandpass filtering and gain adjustment on the three modes of signals respectively, the data acquisition unit performs synchronous digital acquisition of the three modes of signals at a sampling rate of not less than 10MS / s and writes the acquired data into the storage unit; in step S6, the hierarchical alarm of the audible and visual warning device includes: triggering a level one alarm when the discharge signal amplitude exceeds a first preset threshold; triggering a level two alarm when the discharge signal amplitude exceeds a second preset threshold or the duration exceeds a preset time window; and triggering a level three alarm when the discharge signal amplitude exceeds a third preset threshold; wherein the first preset threshold, the second preset threshold, and the third preset threshold increase sequentially, and each level of alarm corresponds to a different audible and visual prompt mode.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention overcomes the physical detection blind spots caused by the limitations of arm length and line of sight in traditional manual handheld detection modes through the coordinated operation of the flipping component and the tilt adjustment component. The flipping component adopts a structure in which the T-shaped frame is driven by the second drive cylinder to flip around the horizontal axis. The rotational motion is transmitted to the right-angle frame through the support rod, so that the carrier plate and all the detection components mounted on it can be unfolded from the storage state inside the box to any working height, realizing a large-area coverage of the multimodal partial discharge sensor in the vertical direction. On this basis, the tilt adjustment component pushes the first drive cylinder to move along the right-angle groove guide slide at the cantilever end of the adjustment frame through the third drive cylinder. By utilizing the sliding cooperation between the pulley and the guide slide, the sensor as a whole is forced to rotate at a deterministic angle, thereby accurately locking the detection surface of the multimodal partial discharge sensor in any one of the three standard detection postures: 45° upward, horizontal, and 45° downward. The above structural design enables the sensor to reach the top and bottom areas of the cabinet, which are not effectively covered by traditional manual inspection. This eliminates the blind spots caused by the physical limitations of the enclosed space, achieves complete coverage of the entire height range of the switchgear, effectively avoids the risk of missing potential insulation defects at the top and bottom, and significantly improves the quality control level during the factory and initial installation stages.

[0020] 2. This invention effectively solves the technical problems of insufficient anti-interference capability and high false positive rate of traditional single-mode handheld detection devices in complex electromagnetic environments through the integrated design of multimodal sensing fusion and signal conditioning architecture. The multimodal partial discharge sensor integrates three detection modes: ultrasonic sensing channel, transient ground voltage sensing channel, and high-frequency current sensing channel. It can synchronously collect and cross-verify the same discharge source from three different physical dimensions: sound waves, electromagnetic waves, and current pulses. Only when the three modal signals show consistent response can it be determined as a real discharge event, thereby effectively distinguishing real partial discharge signals from environmental electromagnetic interference or mechanical vibration noise, and significantly reducing false positives and false negatives caused by environmental noise contamination of single-mode signals. At the signal processing level, the integrated signal conditioning module inside the enclosure performs bandpass filtering and gain adjustment on the three analog signals, precisely filtering out out-of-band environmental noise interference and retaining only the effective signal components that match the characteristic frequencies of partial discharge. The data acquisition unit synchronously digitally acquires the three conditioned signals at a sampling rate of no less than 10ms / s, ensuring the complete preservation of weak early discharge signals and subsequent traceability analysis. Furthermore, the hinged triangular frame structure composed of the partition beam and the insulating plate not only provides stable lateral support for the detection arm, suppressing relative displacement caused by cabinet vibration or external collisions during detection, but also acts as a physical barrier to effectively isolate the energized switchgear from external operators, ensuring both detection stability and operational safety. This multimodal fusion and precision signal processing structural design enables the equipment to maintain excellent anti-interference performance and detection sensitivity even in unshielded environments, significantly reducing the misjudgment and missed detection rates during the factory and installation stages.

[0021] 3. This invention solves the technical problem of large data dispersion and lack of standardization in traditional manual handheld inspection, which is caused by the difficulty in maintaining constant sensor distance, angle, and pressure. The invention utilizes a standardized adjustment mechanism combining mechanical positioning and cylinder fine-tuning of the distance. The right-angled groove geometry of the guide slide provides rigid mechanical positioning and automatic locking for the three inspection postures, eliminating the need for operators to visually judge or manually adjust the angle based on experience. This replaces the subjective arbitrariness of angle setting in manual inspection, ensuring strict consistency of the inspection angle when comparing multiple switchgear units in the same batch laterally or comparing the same switchgear unit longitudinally at different times. After the posture is locked, the mounting axis of the first drive cylinder remains aligned with the current inspection direction. The extension and retraction of its piston rod only changes the normal distance between the sensor and the cabinet surface without changing the locked inspection angle. This achieves a decoupled adjustment mechanism of first fixing the posture and then adjusting the distance, ensuring that the sensor faces the cabinet surface at a constant standard angle and a preset standard distance during each inspection. As can be seen, this invention forms a complete closed loop from data collection and status determination to graded handling, providing a repeatable, comparable, and traceable quantitative data foundation for establishing standardized baseline status files and full life cycle health files for equipment in the early stages of operation. Attached Figure Description

[0022] To more clearly illustrate the technical solution of the present invention, the drawings used in the description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Figure 1 This is a schematic diagram of the overall structure of the detection device of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the overall structure of the detection device of the present invention. Figure 2 ; Figure 3 This is a schematic diagram of the installation structure of the flipping component and tilt adjustment component of the present invention; Figure 4 This is a schematic diagram of the specific structure of the flipping component of the present invention; Figure 5 This is a schematic diagram of the support beam installation structure of the present invention; Figure 6 This is a schematic diagram of the adjustment frame mounting structure of the present invention; Figure 7 This is a schematic diagram of the pulley mounting structure of the present invention; Figure 8 This is a schematic diagram of the shell structure of the present invention; Figure 9 This is a schematic diagram of the installation structure of the visual interactive terminal of the present invention; In the diagram: 1. Movable base, 2. Tilting assembly, 201. Second drive cylinder, 202. Support, 203. Horizontal axis, 204. T-shaped frame, 205. Support rod, 3. Right-angle frame, 4. Loading plate, 5. Tilt adjustment assembly, 501. Loading seat, 502. Adjustment frame, 503. Guide slide, 504. Pulley, 505. Third drive cylinder, 6. First drive cylinder, 7. Terminal corner plate, 8. Multimodal partial discharge sensor, 9. Square channel, 10. Fixed beam, 11. Partition beam, 12. Support beam, 13. Insulation board, 14. Box shell, 15. Box panel, 16. Box door, 17. Wiring hole, 18. Door lock handle, 19. Upright pole, 20. Slide, 21. Locking rod, 22. Visual interactive terminal, 23. Sound and light warning device, 24. Support foot, 25. Universal wheel. Detailed Implementation

[0023] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the specific embodiments. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0024] This specific embodiment provides a complete set of switchgear fault discharge detection equipment, such as... Figures 1-9 As shown; including a movable base 1, the movable base 1 is a rectangular structure, welded from high-strength aluminum alloy and carbon steel, with sufficient rigidity and resistance to bending and torsion to support the weight of the upper flipping assembly 2, right-angle frame 3, box shell 14 and all detection components, and resist the reaction force generated by the flipping torque and cylinder thrust during the detection process, ensuring that the overall structure does not flex or deform.

[0025] Support feet 24 are installed at the four corners of the bottom surface of the mobile platform 1. Each support foot 24 adopts a threaded lifting structure. Its upper part is fastened to the bottom surface of the mobile platform 1 via a flange, and its lower part is equipped with a rotatable and adjustable support screw. A circular support pad is fixed to the bottom end of the support screw, and a rubber anti-slip pad is adhered to the bottom surface of the support pad. During transport, the support feet 24 are in a retracted state, and the weight of the equipment is entirely borne by the casters 25. Each support foot 24 is equipped with a caster 25 on its inner side. The casters 25 are made of polyurethane coated wheel surface, which has good wear resistance and quiet characteristics. The top of the wheel frame is connected to the bottom surface of the mobile platform 1 by bolts. The wheel frame can rotate freely 360° around the vertical axis, realizing flexible movement, on-the-spot turning, and precise positioning of the equipment in narrow spaces such as factory workshops, power distribution room corridors, and cable tunnels.

[0026] When the equipment reaches the designated testing station and enters the testing state, the operator rotates the support screws of each support leg 24 to extend them downwards until the support pad presses firmly against the ground. At this time, the movable base 1 is raised until the casters 25 are off the ground. By adjusting the extension length of the four support legs 24, the movable base 1 can remain level even on uneven ground. The rubber anti-slip pads at the bottom of the support legs 24 provide sufficient frictional resistance, effectively preventing horizontal displacement or deflection of the equipment due to cylinder thrust or external collisions during the testing process. This establishes a stable and repeatable physical measurement benchmark for subsequent high-precision attitude adjustment and signal acquisition. This design fundamentally eliminates the positional and angular deviations introduced by the operator's unstable standing, trembling arms, or body swaying during manual handheld testing as described in the background art.

[0027] In addition, a through square groove 9 is provided on the movable base 1. The square groove 9 has a rectangular through-slot structure. The square groove 9 allows the second drive cylinder 201 of the flipping assembly 2 to be installed in the space below the movable base 1, while the T-shaped frame 204 and the support rod 205 can extend upward through the square groove 9 and connect with the right-angle frame 3, which not only ensures the stroke space of the flipping movement, but also minimizes the overall height of the equipment when it is stored. The edges of the square groove 9 are chamfered and deburred to prevent the moving parts from interfering with or scratching the groove wall during the flipping process.

[0028] The enclosure 14 is fixedly mounted on the upper surface of the movable base 1, located to the side of the square groove 9. The enclosure 14 has an overall rectangular box structure. The internal space of the enclosure 14 is rationally partitioned to accommodate core electronic components such as the signal conditioning module, data acquisition unit, power management module, and control motherboard.

[0029] The side of the housing 14 closest to the square slot 9 is open. When the flipping assembly 2 is in its closed, stowed state, the right-angle frame 3 and its mounted carrier plate 4, tilt adjustment assembly 5, first drive cylinder 6, terminal corner plate 7, and multi-mode partial discharge sensor 8 are all completely housed within the internal cavity of the housing 14. The side wall height of the housing 14 is specially designed to ensure that all the aforementioned components are surrounded by the walls of the housing 14 in the stowed state and do not exceed the outer contour of the housing 14.

[0030] The aforementioned storage design brings two significant technical benefits. First, during equipment transport and in non-operating states, all precision testing components are housed within the enclosure 14. The overall outer contour of the equipment is compressed to the size range of the enclosure 14 and the movable base 1, significantly reducing the space occupied by the equipment. This allows it to pass smoothly through narrow power distribution room door frames, cable trench cover openings, and congested switchgear bay passages, greatly increasing the flexibility of equipment transport in complex field environments. Second, the enclosure 14 forms a complete physical protective shell for the internal precision components, effectively isolating them from impacts during transportation, dust splashes during on-site construction, and moisture corrosion during storage. This prevents damage or contamination to the sensitive probe of the multimodal partial discharge sensor 8, the mating surface of the precision guide slide 503, and the cylinder seals, thereby extending the service life of the equipment and ensuring the consistency of testing accuracy.

[0031] A cable threading hole 17 is provided on one side panel 15 of the enclosure 14. The cable threading hole 17 is used for the orderly passage of sensor signal cables and power cables, preventing the cables from being cut by the hole wall during repeated bending. The other side of the enclosure 14 is provided with a door 16, which is connected to the enclosure by a hinge. The door 16 is equipped with a door lock handle 18, which allows operators to open the door 16 to inspect, replace, or upgrade the signal conditioning module, data acquisition unit, and power module inside the enclosure 14.

[0032] The tilting assembly 2 includes a second drive cylinder 201 and a support 202. The second drive cylinder 201 is a double-acting cylinder, with its cylinder head hinged to the top surface of the movable base 1 outside the square groove 9 via a pin seat, and the piston rod facing upwards. The support 202 is fastened to the upper surface of the movable base 1 outside the square groove 9. A transversely arranged horizontal shaft 203 is rotatably mounted inside the support 202 via bearings. The axis of the horizontal shaft 203 is parallel to the width direction of the movable base 1. A T-shaped frame 204 is fixedly connected to the outer wall of the horizontal shaft 203. The T-shaped frame 204 is T-shaped in overall shape, and one side of its horizontal section is fixedly connected to the outer wall of the horizontal shaft 203. The top of the piston rod of the second drive cylinder 201 is fastened to the bottom of the horizontal section of the T-shaped frame 204. When the piston rod of the second drive cylinder 201 extends, it pushes the T-shaped frame 204 to rotate upward around the horizontal axis 203. When the piston rod retracts, the T-shaped frame 204 rotates downward around the horizontal axis 203 under the action of gravity and cylinder restoring force.

[0033] The top of the T-shaped frame 204 is securely connected to the right-angle frame 3 via a support rod 205. The support rod 205 is a rigid connecting rod, with both ends welded to the top of the T-shaped frame 204 and the bottom of the right-angle frame 3, respectively, transmitting the rotational motion of the tilting assembly 2 to the right-angle frame 3. The right-angle frame 3 has an overall L-shaped bent structure, with its horizontal section connected to the support rod 205 and its vertical section extending outwards to provide an installation platform for the loading plate 4 and the tilt adjustment assembly 5.

[0034] In the retracted state, the piston rod of the second drive cylinder 201 is fully retracted, and the T-shaped frame 204 and the right-angle frame 3 are flipped downwards to their lowest position, with the right-angle frame 3 and all the detection components mounted on it retracted into the housing 14. In the detection state, the piston rod of the second drive cylinder 201 extends, driving the T-shaped frame 204 to flip upwards around the horizontal axis 203 to its working angle, and the right-angle frame 3 and all the detection components are removed from the housing 14. By controlling the stroke of the second drive cylinder 201, the unfolded height of the right-angle frame 3 can be adjusted, allowing the multimodal partial discharge sensor 8 to adjust its orientation angle, overcoming the angular physical limitations described in the background art and eliminating the detection blind spot outside the cabinet.

[0035] The partition protection structure includes a fixed beam 10, a partition beam 11, a support beam 12, and an insulating plate 13. The fixed beam 10 is a vertically arranged profile column, its bottom end fastened to the side of the movable base 1 by bolts, and its top end has a hinge lug. One end of the partition beam 11 is hinged to the top end of the fixed beam 10 via a hinge shaft, allowing it to rotate in the vertical plane around the hinge point. The support beam 12 is a diagonal brace, its two ends hinged to both the fixed beam 10 and the partition beam 11, forming a hinged triangular frame structure. This triangular frame structure forms a stable, geometrically invariant system in the unfolded state, providing reliable lateral support for the flipped detection arm and preventing overturning and vibration under heavy loads or cylinder thrust.

[0036] An insulating plate 13 is fixedly installed on the inner side of the partition beam 11. The insulating plate 13 is made of epoxy resin board or SMC molded board with a thickness of not less than 5mm, and has excellent electrical insulation performance and mechanical strength. The insulating plate 13 is firmly connected to the right-angle frame 3 and unfolds synchronously with the flipping assembly 2. After flipping into place, the partition beam 11 and the insulating plate 13 place the switchgear to be tested in the inner area. This design has a dual technical effect: on the one hand, the partition beam 11 and the insulating plate 13 act as a physical barrier to effectively isolate the energized switchgear from the operators on the outside, preventing the testing personnel from accidentally touching the energized parts during operation and ensuring personal safety; on the other hand, the triangular frame structure and the partition beam 11 provide lateral constraint and stable support for the switchgear, suppressing the cabinet shaking caused by the switchgear's own vibration, cable stress or external collision during the testing process, ensuring that the relative position between the multi-mode partial discharge sensor 8 and the cabinet surface remains constant, thereby ensuring the accuracy and repeatability of the test results.

[0037] The mounting plate 4 is a rectangular flat plate structure, which is fastened to the outer surface of the vertical section of the right-angle frame 3 by bolts. The mounting plate 4 provides an installation reference surface for the tilt adjustment assembly 5 and its auxiliary components, and its flatness and installation accuracy directly affect the accuracy of subsequent attitude adjustment.

[0038] The tilt adjustment assembly 5 includes two carrier seats 501, two adjustment brackets 502, a guide slide 503, a pulley 504, and a third drive cylinder 505. The two carrier seats 501 are symmetrically arranged and are fastened to the carrier plate 4 by bolts, providing support for the entire tilt adjustment assembly 5. Adjustment brackets 502 are fastened to the outer sides of the two carrier seats 501 respectively. The adjustment brackets 502 are C-shaped cantilevered, with their roots fixedly connected to the carrier seats 501 and the cantilever ends extending outwards.

[0039] The cantilever end of the adjusting frame 502 is provided with a guide groove 503. The guide groove 503 is a through groove that runs through the cantilever end of the adjusting frame 502. Its trajectory is a right-angle groove, which is formed by two mutually perpendicular straight line segments connected by a middle corner. The middle corner of this right-angle groove is chamfered to form a smooth transition arc segment. The radius of curvature of this arc segment is determined according to the outer diameter of the pulley 504 and the requirements for smooth movement, ensuring that the pulley 504 does not get stuck, impact, or disengage when passing through the corner. After the posture is reversed, the orientation of the guide groove 503 in space is determined as follows: its two ends are located at the highest point and the lowest point, respectively, and the middle corner is located at the middle height between the two ends.

[0040] The first drive cylinder 6 is arranged between two adjusting brackets 502, with pulleys 504 symmetrically mounted on both sides of its cylinder body. The pulleys 504 are made of wear-resistant engineering plastic, with their outer edges embedded in the inner wall of the guide groove 503, forming a sliding fit with the guide groove 503. The cylinder body end of the third drive cylinder 505 is hinged to the carrier plate 4 via a hinge seat, and the piston rod end of the third drive cylinder 505 is hinged to the cylinder body of the first drive cylinder 6. When the piston rod of the third drive cylinder 505 extends or retracts, it pushes the first drive cylinder 6 to move along the trajectory of the guide groove 503. Since the guide groove 503 is a fixed right-angle groove trajectory, the sliding of the pulleys 504 within the groove forces the first drive cylinder 6 and its front-end mounted terminal corner plate 7 and multi-mode partial discharge sensor 8 to undergo a deterministic angular rotation.

[0041] The two ends and the middle corner of the guide chute 503 correspond to three discrete locking positions. When the pulley 504 moves to the lowest end of the guide chute 503, the first drive cylinder 6 and the multi-mode partial discharge sensor 8 are guided to the lowest position. At this time, the detection surface of the multi-mode partial discharge sensor 8 is precisely locked at a 45° downward angle. This orientation is used to align with low-level detection objects such as the bottom cable compartment of the switchgear, cable entry and exit terminals, and bottom insulation supports. When the pulley 504 moves to the highest end of the guide chute 503, the first drive cylinder 6 and the multi-mode partial discharge sensor 8 are guided to the highest position. At this time, the detection surface of the multi-mode partial discharge sensor 8 is precisely locked at a 45° upward angle. This orientation is used to align with high-level detection objects such as the top insulators of the switchgear, busbar through-wall bushings, and gaps in the top of the switchgear. When the pulley 504 moves to the arc-shaped corner in the middle of the guide slide 503, the first drive cylinder 6 and the multi-mode partial discharge sensor 8 are in the middle position. At this time, the detection surface of the multi-mode partial discharge sensor 8 is precisely locked in a horizontal orientation. This orientation is used to align with the middle detection objects such as the switch cabinet panel, the circuit breaker room observation window, and the instrument room partition.

[0042] The three preset postures mentioned above are mechanically limited and automatically locked by the geometry of the guide slide 503, eliminating the need for operators to visually judge or manually adjust the angle. This replaces the subjective arbitrariness of manual adjustment based on experience as described in the background technology, ensuring strict consistency of the detection angle when comparing multiple switch cabinets in the same batch laterally or comparing the same switch cabinet at different times longitudinally.

[0043] After the detection posture is locked by the guide groove 503, to further eliminate the signal amplitude attenuation difference caused by the inconsistent distance between the sensor and the cabinet surface, the first drive cylinder 6 is configured to push the terminal corner plate 7 to translate along the detection direction via the extension and retraction of its piston rod. The terminal corner plate 7 is an L-shaped bent plate, with its vertical section firmly connected to the piston rod end of the first drive cylinder 6, and its horizontal section used to install the multimode partial discharge sensor 8. Since the mounting axis of the first drive cylinder 6 is consistent with the detection direction in the current locked posture, the extension and retraction of its piston rod only changes the normal distance between the multimode partial discharge sensor 8 and the surface of the cabinet under test, without changing the detection angle already locked by the guide groove 503. The above-mentioned adjustment mechanism of first fixing the posture and then adjusting the distance ensures that the sensor faces the cabinet surface at a constant standard angle and a preset standard distance during each test, laying a solid mechanical foundation for obtaining repeatable and comparable standardized test data, and effectively solving the problem of large data dispersion and difficulty in establishing a baseline state file in the early stage of equipment operation mentioned in the background art.

[0044] The multimodal partial discharge sensor 8 is the core detection and execution element of this equipment, fixedly mounted on the terminal corner plate 7, and its attitude and spacing are adjusted synchronously with the terminal corner plate 7. The multimodal partial discharge sensor 8 integrates three detection modes: an ultrasonic sensing channel, a transient ground voltage (TEV) sensing channel, and a high-frequency current (HFCT) sensing channel. It can simultaneously acquire acoustic wave signals, electromagnetic wave signals, and current pulse signals generated by partial discharge inside the switchgear. The coordinated operation of the multimodal sensing channels enables the equipment to cross-verify the same discharge source from different physical dimensions, effectively distinguishing real discharge signals from environmental electromagnetic interference or mechanical vibration noise, significantly reducing the false positive rate and false negative rate caused by environmental noise as described in the background art.

[0045] The signal processing unit is integrated inside the housing 14, including a signal conditioning module and a data acquisition unit. The signal conditioning module performs bandpass filtering, gain adjustment, and impedance matching on the three analog signals output from the multimode partial discharge sensor 8, respectively, to filter out out-of-band environmental noise interference. The data acquisition unit synchronously digitizes the three conditioned signals at a sampling rate of not less than 10 MS / s and writes the raw data to the built-in storage unit to ensure the complete preservation of weak discharge signals and subsequent traceability.

[0046] The human-machine interface unit includes a visual interactive terminal 22 and an audible and visual alarm 23. A vertical pole 19, which is a round or square tube, is fixedly installed on the side of the enclosure 14. A slide 20 is slidably fitted around the outer periphery of the pole 19, allowing it to slide up and down along the pole and be locked at any height by a locking rod 21. The visual interactive terminal 22, an industrial-grade LCD screen, is fixedly installed on the slide 20, displaying the discharge detection waveform, amplitude trend, spectrum analysis, and equipment operating status in real time. The testing personnel can adjust the height of the visual interactive terminal 22 by loosening the locking rod 21 and then re-locking it according to their height and the available line of sight, obtaining the optimal viewing angle. An audible and visual alarm 23 is fixedly installed on the top of the enclosure 14. When an abnormal discharge signal is detected, a graded audible and visual alarm is triggered based on the signal amplitude and duration, providing immediate on-site feedback of the detection results and a visual indication of the risk level.

[0047] The foregoing has described in detail an embodiment of a complete switchgear fault discharge detection device. Based on the complete switchgear fault discharge detection device described in the above embodiment, this invention also provides a complete switchgear fault discharge detection method corresponding to the detection device, including the following steps: S1. Equipment Positioning: In the stowed state, the mobile base 1 is moved to the designated testing position of the switchgear to be tested using the casters 25. Upon arrival, the four support legs 24 are rotated sequentially to extend downwards and press firmly against the ground. The extension length of each support leg 24 is finely adjusted to keep the mobile base 1 level, ensuring the casters 25 are completely detached from the ground. The rubber anti-slip pads on the bottom of the support legs 24 provide sufficient frictional resistance, effectively preventing equipment displacement or deflection during testing. This establishes a stable physical reference for subsequent high-precision testing, eliminating positional errors caused by personnel shaking during manual handheld testing.

[0048] S2. Coarse Adjustment Orientation: Activate the second drive cylinder 201 of the flipping assembly 2, driving the T-shaped frame 204 to flip upwards around the horizontal axis 203, causing the right-angle frame 3 and all detection components to unfold from inside the housing 14 to the working position. Simultaneously, the partition beam 11 and the insulating plate 13 unfold synchronously with the right-angle frame 3, placing the switchgear under test in the inner area, forming a safety isolation barrier and providing lateral stability support. Based on the approximate height of the part under test, fine-tune the unfolding angle of the right-angle frame 3 by controlling the stroke of the second drive cylinder 201, roughly adjusting the multimodal partial discharge sensor 8 to face the surface under test, eliminating detection blind spots at the top and bottom of the switchgear, and providing an initial position basis for subsequent attitude fine-tuning.

[0049] S3. Attitude Fine-tuning: The third drive cylinder 505 of the drive tilt adjustment component 5 pushes the first drive cylinder 6 to move along the guide slide 503 of the adjustment frame 502. Since the guide slide 503 is a right-angled groove with a chamfered arc at the middle corner, the sliding of the pulley 504 within the groove forces the multimodal partial discharge sensor 8 to undergo a deterministic rotation: when the pulley 504 is at the lowest end of the guide slide 503, the sensor is locked in a 45° downward angle, used to align with low-level objects such as the cable compartment at the bottom of the cabinet; when the pulley 504 is at the highest end, the sensor is locked in a 45° upward angle, used to align with high-level objects such as the insulator at the top of the cabinet; when the pulley 504 is at the middle arc-shaped corner, the sensor is locked in a horizontal orientation, used to align with mid-level objects such as the middle panel of the cabinet. These three preset attitudes are mechanically limited and automatically locked by the geometry of the guide slide 503, eliminating the need for manual visual adjustment and ensuring the standardization and consistency of the detection angle.

[0050] S4. Spacing Fine-tuning: Under the premise of locked detection posture, the piston rod of the first drive cylinder 6 is controlled to extend and retract, pushing the terminal corner plate 7 and the multi-mode partial discharge sensor 8 to translate along the normal of the current detection direction. Since the mounting axis of the first drive cylinder 6 is consistent with the detection direction, its extension and retraction only changes the normal spacing between the sensor and the cabinet surface, without changing the locked detection angle, thus achieving posture fixation and spacing adjustment. After the spacing is precisely adjusted to the preset standard value, it is locked to ensure that the sensor couples to the cabinet surface at a constant angle and standard distance during each detection, eliminating signal amplitude deviation caused by distance fluctuations, and laying the foundation for obtaining repeatable and comparable standardized data.

[0051] S5. Signal Acquisition: The multimodal partial discharge sensor 8 is activated, simultaneously opening three sensing channels: ultrasonic, transient ground voltage, and high-frequency current, to continuously monitor partial discharge activity inside the switchgear. The three analog signals undergo bandpass filtering and gain adjustment by the signal conditioning module within the enclosure 14, and are then synchronously digitized by the data acquisition unit at a sampling rate of no less than 10 MS / s. During acquisition, the visual interactive terminal 22 displays the signal waveform and spectrum in real time, allowing operators to intuitively assess coupling status and interference. After each acquisition cycle, the raw data, along with metadata such as attitude angle, normal distance, and timestamp, is written to the storage unit to ensure complete preservation of weak discharge signals and subsequent traceability. If signal quality is abnormal, the system prompts for recalibration or adjustment followed by re-acquisition to prevent invalid data from being mixed in.

[0052] S6. Status Monitoring and Alarms: Throughout the detection process, the visual interactive terminal 22 displays the discharge detection data and equipment operating status in real time. Operators can adjust the height of the slide 20 on the pole 19 to obtain the best viewing angle. When the system determines that an abnormal discharge signal exists, the audible and visual alarm 23 triggers a tiered alarm according to preset rules. When the discharge signal amplitude exceeds the first preset threshold, a level 1 alarm is triggered (slow yellow flashing and low-frequency warning sound), and it is marked as a state of concern, prompting a focus on retesting during the next routine inspection; when the amplitude exceeds the second preset threshold or the duration exceeds the preset window, a level 2 alarm is triggered (fast orange flashing and medium-frequency warning sound), marking it as a state of re-inspection, and suggesting that the detection be intensified in the short term or that a power outage inspection be arranged; when the amplitude exceeds the third preset threshold, a level 3 alarm is triggered (constant red light and high-frequency alarm sound), marking it as a state of serious defect, prompting immediate reporting and evaluation for emergency handling. Alarm information at all levels, along with the original data, analysis results, and handling suggestions, are stored together to form a complete and traceable record. After a single switch cabinet is tested, the second drive cylinder 201 is controlled to reverse and retract all components into the housing 14, restoring the storage state for transfer to the next work station.

[0053] As can be seen from the above, compared with the prior art, the present invention systematically solves the three core defects of the traditional manual handheld detection method through the coordinated cooperation of the basic mobile support unit, storage and protection unit, posture flipping unit, precision adjustment unit and multimodal sensing unit. First, the mechanically limited guide rails automatically lock the sensor in three standard postures: 45° downward, horizontal, and 45° upward. This replaces the subjective arbitrariness of manual angle adjustment based on experience, ensuring strict consistency of the detection angle during horizontal comparisons of the same batch and longitudinal comparisons of the same equipment. Second, the flipping assembly unfolds the detection component from inside the enclosure to the working position, allowing the sensor to reach the top insulator area and bottom cable compartment area of ​​the switchgear. This overcomes the physical limitations of manual arm length and line of sight, eliminating blind spots at the top and bottom of the cabinet. Third, the adoption of a posture-first, distance-later adjustment mechanism ensures that the sensor couples to the cabinet surface at a constant standard angle and preset standard distance each time. Combined with multi-modal signal synchronous acquisition and hierarchical alarm judgment, this significantly reduces the false positive and false negative rates caused by environmental noise. The acquired data is repeatable and comparable, providing a standardized data foundation for establishing a full life-cycle health record for the equipment. Meanwhile, the storage and protection unit allows all precision components to be completely stored inside the enclosure when not in operation. This reduces the space occupied during transportation, improves the passability in complex on-site environments, effectively isolates the equipment from transportation bumps, dust and moisture, extends the service life of the equipment, and ensures the long-term stability of testing accuracy.

[0054] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A complete set of switchgear fault discharge detection equipment, comprising a movable base (1), characterized in that, A flipping assembly (2) is hinged to the movable base (1). A right-angle bracket (3) is fixedly mounted on the rotation output end of the flipping assembly (2). A carrier plate (4) is fixedly mounted on the right-angle bracket (3). A tilt adjustment assembly (5) is fixedly mounted on the carrier plate (4). A first drive cylinder (6) is fixedly mounted on the movable output end of the tilt adjustment assembly (5). A terminal angle plate (7) is fixedly mounted on the piston rod end of the first drive cylinder (6). A multi-mode partial discharge sensor (8) is fixedly mounted on the terminal angle plate (7). The angle adjustment component (5) is configured to drive the first drive cylinder (6), the terminal corner plate (7) and the multimodal partial discharge sensor (8) to rotate as a whole via the displacement of its moving output end, so as to switch and lock the multimodal partial discharge sensor (8) to any one of the horizontal, 45° upward and 45° downward tilt detection postures; the first drive cylinder (6) is configured to push the terminal corner plate (7) to translate via the extension and retraction of its piston rod, so as to finely adjust the detection distance between the multimodal partial discharge sensor (8) and the test surface of the complete switch cabinet while keeping the detection posture unchanged.

2. The complete set of switchgear fault discharge detection equipment according to claim 1, characterized in that, The movable base (1) has a through square groove (9). The flipping assembly (2) includes a second drive cylinder (201) and a support (202). The second drive cylinder (201) is hinged to the inside of the square groove (9). The support (202) is fastened to the movable base (1) and arranged on the outside of the square groove (9). A transverse shaft (203) is rotatably installed inside the support (202). A T-shaped frame (204) is fixedly connected to the outer wall of the transverse shaft (203). The piston rod of the second drive cylinder (201) is arranged upward and its end is fastened to the bottom of the T-shaped frame (204). The top of the T-shaped frame (204) is fastened to the right angle frame (3) through a support rod (205).

3. The complete set of switchgear fault discharge detection equipment according to claim 1, characterized in that, A vertically arranged fixed beam (10) is fixedly installed on the side of the movable base (1). A partition beam (11) is hinged to the top of the fixed beam (10). A support beam (12) is provided between the partition beam (11) and the fixed beam (10). The two ends of the fixed beam (10) are respectively hinged to the partition beam (11) and the support beam (12). The fixed beam (10), the partition beam (11), and the support beam (12) together form a hinged triangular frame structure. An insulating plate (13) is fixedly installed on the inner side of the partition beam (11). The insulating plate (13) is fastened to the right angle frame (3).

4. The complete set of switchgear fault discharge detection equipment according to claim 1, characterized in that, The tilt adjustment assembly (5) includes two carrier seats (501) that are fastened to the carrier plate (4). Adjustment frames (502) are fastened to the sides of the two carrier seats (501). The first drive cylinder (6) is arranged between the two adjustment frames (502). The adjustment frame (502) is a C-shaped cantilever structure. The cantilever end of the adjustment frame (502) is provided with a guide groove (503). The guide groove (503) is a right-angle groove structure. Pulleys (504) are installed on both sides of the first drive cylinder (6). The pulleys (504) slide in cooperation with the inner wall of the guide groove (503).

5. The complete set of switchgear fault discharge detection equipment according to claim 4, characterized in that, A third driving cylinder (505) is provided on the carrier plate (4). The piston rod of the third driving cylinder (505) is arranged upward. The cylinder body end of the third driving cylinder (505) is hinged to the carrier plate (4). The piston rod end of the third driving cylinder (505) is arranged between two adjusting brackets (502). The piston rod end of the third driving cylinder (505) is hinged to the cylinder body of the first driving cylinder (6).

6. The complete set of switchgear fault discharge detection equipment according to claim 1, characterized in that, A housing (14) is fixedly installed on the movable base (1). The housing (14) has an opening on the side facing the multimodal partial discharge sensor (8). The interior of the housing (14) is a component mounting area, in which a signal conditioning module and a data acquisition unit are integrated. The two sides of the housing (14) are a housing plate (15) and a housing door (16), respectively. A wire hole (17) is opened on the housing plate (15), and a door lock handle (18) for opening, closing and locking is installed on the housing door (16).

7. The complete set of switchgear fault discharge detection equipment according to claim 6, characterized in that, A vertical rod (19) is fixedly installed on the side of the housing (14). A slide (20) is slidably sleeved on the outer periphery of the vertical rod (19). A locking rod (21) for locking the axial position of the slide (20) is arranged between the slide (20) and the vertical rod (19). A visual interactive terminal (22) is fixedly installed on the slide (20). The visual interactive terminal (22) is configured to display discharge detection data and equipment operating status in real time. An audible and visual alarm (23) is fixedly installed on the top of the housing (14). The audible and visual alarm (23) is configured to trigger a graded alarm when an abnormal discharge signal is detected.

8. The complete set of switchgear fault discharge detection equipment according to claim 1, characterized in that, The bottom of the movable platform (1) is equipped with multiple support feet (24), and each support foot (24) is equipped with a caster wheel (25) on its inner side. The support feet (24) are configured to support the movable platform (1) and keep it horizontal during the testing process. The caster wheel (25) is configured to carry the movable platform (1) during the transfer process to achieve movement and turning. The bottom of the support feet (24) is provided with anti-slip pads to prevent the movable platform (1) from shifting during the testing process.

9. A method for detecting fault discharge in a complete set of switchgear, characterized in that, Based on the complete switchgear fault discharge detection equipment as described in any one of claims 1 to 8, the method includes the following steps: S1. Equipment positioning: The mobile base (1) is moved to the predetermined testing position of the switch cabinet to be tested by means of casters (25), and the support legs (24) are unfolded to keep the mobile base (1) horizontal and locked to prevent displacement during the testing process. S2, Coarse adjustment of orientation: Start the flipping component (2), drive the right angle frame (3) to flip, and adjust the mounting plate (4) and the multi-mode partial discharge sensor (8) as a whole to face the preset detection surface of the switch cabinet to be tested; S3, attitude fine adjustment: drive the tilt adjustment component (5) to make its moving output end produce displacement, drive the first drive cylinder (6), the terminal corner plate (7) and the multimodal partial discharge sensor (8) to rotate as a whole, switch the multimodal partial discharge sensor (8) to switch and lock it to one of the three detection attitudes of horizontal, 45° upward and 45° downward that matches the surface to be measured; S4. Spacing fine adjustment: Control the piston rod of the first drive cylinder (6) to extend and retract, push the terminal corner plate (7) to move along the detection direction, and adjust the detection spacing between the multimodal partial discharge sensor (8) and the surface to be tested to a preset value while keeping the detection posture unchanged. S5, Signal Acquisition: The multi-mode partial discharge sensor (8) is activated to perform partial discharge detection on the complete switch cabinet. The multi-mode discharge signal acquired by the sensor is conditioned by the signal conditioning module in the enclosure (14) and then digitally acquired and stored by the data acquisition unit. S6. Status monitoring and alarm: The visual interactive terminal (22) displays the discharge detection data and equipment operation status in real time; when an abnormal discharge signal is detected, the audible and visual alarm (23) triggers a graded alarm.

10. The method for detecting fault discharge in a complete set of switchgear according to claim 9, characterized in that, In step S5, the multi-mode partial discharge sensor (8) synchronously acquires three modes of partial discharge signals: ultrasonic signal, transient ground voltage signal and high-frequency current signal; after the signal conditioning module performs bandpass filtering and gain adjustment on the three modes of signals respectively, the data acquisition unit performs synchronous digital acquisition of the three modes of signals at a sampling rate of not less than 10MS / s and writes the acquired data into the storage unit. In step S6, the tiered alarms of the audible and visual alarm device (23) include: triggering a level 1 alarm when the discharge signal amplitude exceeds a first preset threshold; triggering a level 2 alarm when the discharge signal amplitude exceeds a second preset threshold or the duration exceeds a preset time window; and triggering a level 3 alarm when the discharge signal amplitude exceeds a third preset threshold. The first preset threshold, the second preset threshold, and the third preset threshold increase sequentially, and each level of alarm corresponds to a different audible and visual prompting method.

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