High-voltage device high-voltage alternating current withstand voltage test device and method

Abstract

The application relates to the technical field of pressure test, in particular to a high-voltage alternating-current pressure test device and method for high-voltage equipment, which comprises a variable-frequency power supply and a test mechanism connected between the variable-frequency power supply and a tested cable, further comprises a lifting assembly which comprises a fixed frame and a moving frame sliding relative to the fixed frame; a clamping assembly which comprises clamping pieces oppositely arranged at the top of the moving frame; an auxiliary assembly which comprises an auxiliary frame arranged at one side of the moving frame, the auxiliary frame is used for supporting the cable from below, and the top of the auxiliary frame is slidingly connected with oppositely arranged clamping blocks; and a linkage system which comprises a variable-volume air cavity arranged in the moving frame, a variable-pressure assembly for changing the pressure of the variable-volume air cavity is arranged in the variable-volume air cavity, the variable-pressure assembly is used for controlling the clamping action of the clamping pieces and the clamping blocks, and the variable-pressure assembly utilizes airflow damping in the variable-volume air cavity to inhibit the vibration of the tested cable.

Description

Technical Field

[0001] This invention relates to the field of withstand voltage testing technology, specifically to a high-voltage AC withstand voltage testing device and method for high-voltage equipment. Background Technology

[0002] High-voltage AC withstand voltage testing is a crucial method for evaluating the insulation strength and quality of high-voltage equipment such as power cables, transformers, and GIS. It involves applying a high-voltage AC power, either at power frequency or variable frequency, higher than the rated voltage to the equipment to test its ability to withstand overvoltage within a specified time. It is considered the "gold standard" for insulation performance verification. Currently, field testing commonly employs variable frequency series resonant devices, which consist of core electrical components such as a variable frequency power supply, excitation transformer, high-voltage reactor, and capacitive voltage divider. This solution overcomes the problems of bulky and high-capacity requirements associated with traditional power frequency test transformers and has become the mainstream technology.

[0003] For example, patent document CN223841968U relates to the field of cable testing technology, specifically a cable withstand voltage test platform. The platform includes an insulating plate with insulating posts fixed at each of the four corners of its bottom. Support plates are fixed to the underside of the four insulating posts, and two symmetrically positioned storage drawers are located in the middle of the support plates. It also includes two T-shaped frames, each fixed to one side of the top of the insulating plate. A pre-tightening mechanism is provided on the side of each T-shaped frame that is close to the other. A first spring pushes the upper cable frame downwards to press and fix the cable to the top of the lower cable frame. Simultaneously, the movement of the movable frame, via a second spring, drives the cable contact frame to insert cable contact pins into the cable end. A pull rod, pulled by the movable frame, presses the cable contact plate against the cable end on top of the supporting contact plate, thus fixing the cable end. Different voltages are supplied to the cable end through the cable contact plate, supporting contact plate, and cable contact pins, facilitating withstand voltage testing of the cable.

[0004] The existing technology described above can fix cables by setting up upper and lower cable racks. However, in actual AC withstand voltage tests, the cable laying positions (such as trenches, supports, and the ground) are uneven, usually relying on temporary blocks, ropes, or simple clamps. This makes it impossible to accurately control and reproduce the cable's spatial posture (especially the distance to ground), resulting in inconsistencies in key environmental parameters such as capacitance to ground and stray capacitance in each test. This seriously affects the reliability and comparability of precision test results such as dielectric loss measurement and partial discharge detection. Therefore, this application proposes a high-voltage AC withstand voltage test device and method for high-voltage equipment. Summary of the Invention

[0005] The purpose of this invention is to provide a high-voltage AC withstand voltage test apparatus and method for high-voltage equipment, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a high-voltage AC withstand voltage test device for high-voltage equipment, comprising a frequency converter and a test mechanism connected between the frequency converter and the cable under test, and further comprising: A lifting assembly, comprising a fixed frame and a sliding frame that slides relative to the fixed frame; A clamping assembly, comprising clamping plates located on top of the transfer frame and disposed opposite to it; An auxiliary component includes an auxiliary frame located on one side of the transfer frame, the auxiliary frame being used to support the cable from below, and a clamping block slidably connected to the top of the auxiliary frame; The linkage system includes an adjustable air chamber disposed within a moving frame. The adjustable air chamber is equipped with a pressure-changing component that changes its own pressure. The pressure-changing component is used to control the clamping action of the clamping plates and clamping blocks. The pressure-changing component uses the airflow damping within the adjustable air chamber to suppress the vibration of the cable under test.

[0007] Preferably, the lifting assembly further includes a dual-head motor installed at the bottom of the fixed frame, a lead screw driven by the dual-head motor, a moving block threaded with the lead screw, a hinge seat fixedly connected to the side of the moving frame, and a crank rotatably connected between the moving block and the hinge seat. A slide rail for sliding connection of the moving block is fixedly connected to the side of the fixed frame.

[0008] Preferably, the clamping assembly is also rotatably connected to a rocker in the moving frame, one end of the rocker is fixedly connected to one end of the clamping piece, a positioning plate is slidably connected in the moving frame, and a push plate for abutting the bottom of the rocker is fixedly connected to the top of the positioning plate.

[0009] Preferably, the auxiliary component further includes a flexible hollow tube fixedly connected to the side of the transfer frame, one end of the flexible hollow tube being fixedly connected to a telescopic cylinder for supporting the auxiliary frame, a support plate being provided inside the auxiliary frame, limit rods being fixedly connected to both sides of the support plate, and a slanted slide bar being fixedly connected to the side of the clamping block, with the limit rod and the slanted slide bar being slidably connected.

[0010] Preferably, the transformer assembly includes an air cylinder disposed within the shift frame. The top of the air cylinder is connected to the interior of the regulating air chamber via an air supply pipe. The interior of the air supply pipe is provided with multiple damping holes. A cylinder is fixedly connected to the bottom of the air cylinder. The output end of the cylinder extends into the air cylinder and is fixedly connected to a push plug. A movable plug is slidably connected to the interior of the regulating air chamber.

[0011] Preferably, the transformer assembly further includes a hollow push rod fixedly connected to the top of the movable plug, the top of the hollow push rod passing through the shift frame and connected to the positioning plate, one end of the flexible hollow tube being slidably connected to a gas-blocking piston rod adapted thereto, one end of the gas-blocking piston rod being fixedly connected to an expansion piston rod, and one end of the expansion piston rod passing through the auxiliary frame and fixedly connected to the support plate.

[0012] Preferably, a rack is fixedly connected inside the fixed frame, a rotating rod is rotatably connected inside the moving frame, a gear that is connected to the rack is fixedly connected to the outer surface of the rotating rod, and an air delivery impeller housing driven by the rotating rod is provided on the outer surface of the rotating rod. The air delivery impeller housing is connected to the air delivery cylinder through a pressurized air pipe.

[0013] Preferably, it also includes a heat dissipation mechanism, which uses gas in the adjustable gas chamber to dissipate heat from the cable under test. The heat dissipation mechanism includes an air pump fixedly connected to one side of the transfer frame. The air pump's delivery end extends into the adjustable gas chamber. A second solenoid valve is installed inside the hollow push rod. The hollow push rod delivers gas to the push plate for discharge through the second solenoid valve.

[0014] Preferably, the test mechanism includes an excitation transformer, a high-voltage reactor, and a capacitor divider. The excitation transformer is connected between the frequency converter and the high-voltage reactor. The high-voltage end of the capacitor divider is used to connect in parallel with the cable under test, and the low-voltage signal line is connected back to the frequency converter.

[0015] This invention also provides a method for high-voltage AC withstand voltage test of high-voltage equipment, comprising the following steps: S1. Place the cable: Place the end of the cable to be tested between the two clamps, with the lower part of the cable resting on the auxiliary frame; S2. Adjusting the height: Operate the lifting assembly to drive the moving frame to rise or fall to a predetermined height; S3. Linkage and fixing: During the lifting and lowering process of the frame, gas is pumped into the regulating air chamber by driving the transformer assembly to control the clamping action of the clamping plates and clamping blocks; S4. Connect the test circuit: Connect the frequency converter to the cable under test through the test mechanism, set the test parameters and conduct the test; S5. Perform the test and suppress vibration: Start the variable frequency power supply to perform a withstand voltage test. The vibration generated by the cable is transmitted to the transformer assembly through the clamping assembly and the auxiliary assembly, and is consumed by the airflow damping in the adjustable air chamber.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. When adjusting the height of the transfer frame to accommodate cables in different laying positions, the movement of the lifting component automatically drives the impeller inside the air delivery impeller housing to rotate, delivering air to the air delivery cylinder. The pressure changes within the adjustable air chamber then synchronously drive the clamping and auxiliary components. Automatic cable clamping and auxiliary support can be achieved without an additional power source, greatly improving operational efficiency and convenience. The clamping plates hold the cable from the end face, while the clamping blocks support the lower portion of the cable from below. This dual fixing method effectively prevents cable displacement or shaking during testing. Simultaneously, the anti-slip texture and insulating pads on the inner side of the clamping plates, as well as the elastic buffer pads on the inner side of the clamping blocks, protect the cable surface from damage and avoid the risk of electrical short circuits. When the tested cable vibrates, the vibration force is transmitted to the pneumatic system through the clamping blocks and clamping plates, causing the gas in the adjustable air chamber to flow in the opposite direction through the damping orifice. The conical structure of the damping orifice provides damping force for the gas flow, effectively absorbing vibration kinetic energy and significantly improving the stability and safety of the testing process.

[0017] 2. The operator only needs to control the lifting and lowering of the transfer frame to adapt to the cable position. This action is automatically converted into pneumatic power to drive the entire clamping and support system. Gas enters the regulating air chamber through the damping orifice, pushing the movable plug and hollow push rod to make the clamps close precisely. At the same time, the clamp blocks adaptively tighten through the flexible hollow tube and telescopic cylinder. Any vibration energy of the cable is captured by the expansion piston rod and other structures, and converted into the reciprocating flow of gas between the regulating air chamber and the air delivery cylinder. When the gas flows through the specially designed conical damping orifice, it generates strong damping, efficiently dissipating kinetic energy and significantly suppressing cable vibration. This not only protects the cable and the device, but more importantly, it greatly reduces the interference of vibration on weak partial discharge signals and improves diagnostic sensitivity. At the same time, the integrated air pump and second solenoid valve cooling mechanism can guide cooling gas directly to the cable surface at the push plate and support plate. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the first three-dimensional structure of the present invention; Figure 2 This is a schematic diagram of the second three-dimensional structure of the present invention; Figure 3 This is a schematic diagram of the moving frame structure in this invention; Figure 4 This is an exploded structural diagram of the moving frame and the fixed frame in this invention; Figure 5 This is a schematic cross-sectional view of the frame structure in this invention; Figure 6 For the present invention Figure 5 Enlarged structural diagram at point A; Figure 7 This is a schematic diagram of the gear structure in this invention; Figure 8 This is a schematic diagram of the regulating gas chamber in this invention; Figure 9 This is a schematic diagram of the telescopic cylinder in this invention; Figure 10 This is a schematic diagram of the gas delivery cylinder in this invention; Figure 11 This is a schematic diagram of the push plate in this invention; Figure 12 This is a schematic diagram of the clamping block in this invention.

[0019] In the diagram: 100, Variable frequency power supply; 101, Excitation transformer; 102, Gimbal; 103, High-voltage reactor; 104, Capacitor voltage divider; 105, Fixed platform; 200, Moving frame; 201, Fixed frame; 202, Dual-head motor; 203, Lead screw; 204, Slide rail; 205, Moving block; 206, Crank; 207, Hinge seat; 208, Rack; 209, Gear; 210, Rotating rod; 300, Flexible hollow tube; 301, Tie rod; 302, Telescopic cylinder; 303, Auxiliary frame; 304, Clamping block; 305, Support plate; 306, Limiting rod; 307. Slanted slide bar; 308. Air-blocking piston rod; 309. Expansion piston rod; 310. Air vent; 311. First solenoid valve; 312. Clamping plate; 313. Rocker plate; 314. Push plate; 315. Positioning plate; 400. Adjustable air chamber; 401. Air pump; 402. Air delivery cylinder; 403. Cylinder; 404. Air delivery pipe; 405. Air delivery impeller housing; 406. Pressurized air pipe; 407. Top column; 408. Spring; 409. Movable plug; 410. Second solenoid valve; 411. Hollow top rod; 412. Damping orifice; 413. Push plug. Detailed Implementation

[0020] 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.

[0021] Example 1: Please refer to Figure 1 - Figure 12This invention provides a technical solution: a high-voltage AC withstand voltage test device for high-voltage equipment, including a frequency converter 100 and a test mechanism connected between the frequency converter 100 and the cable under test. The frequency converter 100 is used to set test parameters such as target voltage, withstand voltage time, and protection value. The test mechanism includes an excitation transformer 101, a high-voltage reactor 103, and a capacitive voltage divider 104. The excitation transformer 101 is connected between the frequency converter 100 and the high-voltage reactor 103. The high-voltage end of the capacitive voltage divider 104 is used to connect in parallel with the cable under test, and the low-voltage signal line is connected back to the frequency converter 100. The device also includes a fixed platform 105, which is used to support the excitation transformer 101, the high-voltage reactor 103, and the capacitive voltage divider 104. A pan-tilt unit 102 is also fixedly connected to the top of the fixed platform 105 to support the frequency converter 100.

[0022] It also includes a lifting assembly, which includes a fixed frame 201 and a sliding frame 200 that slides relative to the fixed frame 201. The lifting assembly also includes a dual-head motor 202 installed at the bottom of the fixed frame 201, a lead screw 203 driven by the dual-head motor 202, a sliding block 205 threadedly engaged with the lead screw 203, a hinge seat 207 fixedly connected to the side of the sliding frame 200, and a crank 206 rotatably connected between the sliding block 205 and the hinge seat 207. A slide rail 204 for sliding connection of the sliding block 205 is fixedly connected to the side of the fixed frame 201. By setting the dual-head motor 202 to drive the lead screw 203 to rotate, the sliding block 205 can be driven to move. The movement of the sliding block 205 will pull one end of the crank 206 to produce displacement, thereby driving the sliding frame 200 to slide within the fixed frame 201.

[0023] It also includes a clamping assembly, which includes clamping pieces 312 located on top of the transfer frame 200 and arranged opposite each other. The clamping assembly also includes a rocker plate 313 rotatably connected inside the transfer frame 200. One end of the rocker plate 313 is fixedly connected to one end of the clamping piece 312. A positioning plate 315 is slidably connected inside the transfer frame 200. A push plate 314 for abutting against the bottom of the rocker plate 313 is fixedly connected to the top of the positioning plate 315. By setting the clamping pieces 312 to move closer to each other, the end face of the cable under test can be clamped, thereby achieving positioning. By setting the positioning plate 315 to move upward, one end of the rocker plate 313 can be pushed to tilt and pull the clamping piece 312 to move, thereby causing the two clamping pieces 312 to move closer to each other and close, thereby achieving clamping of the cable under test.

[0024] It also includes auxiliary components, including an auxiliary frame 303 located on one side of the transfer frame 200, which supports the cable from below. A clamping block 304 is slidably connected to the top of the auxiliary frame 303. The auxiliary components also include a flexible hollow tube 300 fixedly connected to the side of the transfer frame 200. One end of the flexible hollow tube 300 is fixedly connected to a telescopic cylinder 302 for supporting the auxiliary frame 303. A support plate 305 is provided inside the auxiliary frame 303, and limit rods 306 are fixedly connected to both sides of the support plate 305. The side of the clamping block 304 is fixedly connected with a slanted slide bar 307, and the limiting rod 306 is slidably connected to the slanted slide bar 307. By setting the clamping blocks 304 to be close to each other, auxiliary support can be provided for the cable under test. The telescopic cylinder 302 can change according to the amount of fluid inside it, so it can extend synchronously when the moving frame 200 moves upward, thereby pushing the auxiliary frame 303 upward and increasing its own support height. The pull rod 301 can assist in supporting the flexible hollow tube 300, thereby improving the support strength of the auxiliary frame 303.

[0025] It also includes a linkage system, which includes an adjustable air chamber 400 set in the shift frame 200. The adjustable air chamber 400 is equipped with a pressure changing component that changes its own pressure. The pressure changing component is used to control the clamping action of the clamping plate 312 and the clamping block 304. The pressure changing component uses the airflow damping in the adjustable air chamber 400 to suppress the vibration of the cable under test. By setting the pressure changing component, power can be provided to the clamping plate 312 and the clamping block 304 to achieve automated clamping.

[0026] The transformer assembly includes an air cylinder 402 disposed within the shift frame 200. The top of the air cylinder 402 is connected to the interior of the regulating air chamber 400 via an air supply pipe 404. The interior of the air supply pipe 404 is provided with multiple damping holes 412. A cylinder 403 is fixedly connected to the bottom of the air cylinder 402. The output end of the cylinder 403 extends into the air cylinder 402 and is fixedly connected to a push plug 413. A movable plug 409 is slidably connected inside the regulating air chamber 400. By operating the cylinder 403, its output end drives the push plug 413 to move, thereby compressing the gas in the air cylinder 402 and delivering it to the regulating air chamber 400 through the air supply pipe 404, thereby pushing the movable plug 409 to move. The damping holes 412 have damping force, which can suppress the reset action of the movable plug 409.

[0027] When the cable under test vibrates, it will act on the clamp 304 and clamp 312, causing them to be reset by force. At this time, the pressure in the regulating air chamber 400 will change, thereby squeezing the movable plug 409 to move down and allowing the fluid to flow in the damping hole 412 in the opposite direction. At this time, the damping hole 412 will apply damping force to the fluid, absorb the kinetic energy in the fluid, and thus suppress the kinetic energy of the cable under test.

[0028] Specifically, during use, one end of the cable to be tested is fixed within two clamps 312, while the lower surface of the cable is placed on the auxiliary frame 303, which provides auxiliary support for the cable. Then, the frequency converter 100 is connected to the excitation transformer 101, which in turn is connected to the high-voltage reactor 103. The high-voltage reactor 103 is then connected to the cable under test. The high-voltage end of the capacitive voltage divider 104 is connected in parallel with the cable under test, and the low-voltage signal line of the capacitive voltage divider 104 is connected back to the main frequency converter 100. Parameters such as the target test voltage, withstand voltage time, and overvoltage / overcurrent protection values ​​are set on the frequency converter 100. Since the cable laying positions vary in the field, the clamps 312 can be adjusted by changing the height of the moving bracket 200. The position of the auxiliary frame 303 ensures that the spatial position of the cable relative to the ground and other objects is fixed, so that parameters such as capacitance to ground and stray capacitance remain consistent in each test. This also prevents damage to the cable termination due to improper force or damage to the insulation due to friction or compression. The lead screw 203 is driven to rotate by activating the dual-head motor 202. The lead screw 203 drives the shift block 205 to rotate, causing one end of the crank 206 to tilt. This causes the other end of the crank 206 to push the hinge seat 207 to move, ultimately causing the shift frame 200 to slide upwards within the fixed frame 201. Simultaneously, as the shift frame 200 moves relative to the fixed frame 201, the gear 209 abuts against the rack 208, driving the rotating rod 210 to rotate. At this time, the rotating rod 210 drives the air impeller. The impeller inside shell 405 rotates, delivering external air through pressurized air pipe 406 to the interior of air delivery cylinder 402. The increased gas volume in air delivery cylinder 402 then passes through air delivery pipe 404, through multiple damping holes 412, and into the bottom of regulating air chamber 400, pushing the movable stopper 409 upwards. This upward movement of the movable stopper 409 pushes the hollow push rod 411 upwards. The upward movement of the hollow push rod 411 then moves the positioning plate 315 and its top push plate 314. The push plate 314 abuts against one end of the rocker 313, causing the rocker 313 to flip and causing the two clamping plates 312 to come closer together and clamp the cable to be tested. As the movable stopper 409 moves upwards, it compresses the gas in regulating air chamber 400 through the tough hollow tube 3... The gas is delivered to the inside of the telescopic cylinder 302. At this time, the gas enters the telescopic cylinder 302 through the flexible air tube 300, which pushes the piston end of the gas-blocking piston rod 308 to move, thereby pushing the support plate 305 to move. The support plate 305 will drive one end of the limiting rod 306 to slide in the inclined slide bar 307. At this time, the inclined slide bar 307 is constructed with an inclined surface, which will drive the clamping block 304 to move relatively closer under the traction force of the limiting rod 306, thereby providing auxiliary support for the cable. When the moving stroke of the shift frame 200 is insufficient or the height adjustment is not required, the cylinder 403 can be operated to drive the cylinder 403 to move in the air delivery cylinder 402, so that the gas in the air delivery cylinder 402 flows into the regulating air chamber 400 through the air delivery pipe 404, thereby driving the movable plug 409.

[0029] In summary, when the height of the shift bracket 200 is adjusted to accommodate cables at different laying locations, the movement of the lifting assembly automatically drives the impeller inside the air delivery impeller housing 405 to rotate, delivering air to the air delivery cylinder 402. This, in turn, synchronously drives the clamping and auxiliary components through changes in air pressure within the regulating air chamber 400. Automatic cable clamping and auxiliary support can be achieved without an additional power source, significantly improving operational efficiency and convenience. The clamping plate 312 clamps the cable from the end face, while the clamping block 304 supports the lower portion of the cable from below. This dual-fixing method effectively prevents electrical leakage. During the test, the cable may shift or sway. Meanwhile, the anti-slip texture and insulating pad on the inner side of the clamp 312 and the elastic buffer pad on the inner side of the clamp 304 can protect the cable surface from damage and avoid the risk of electrical short circuit. When the cable under test vibrates, the vibration force is transmitted to the pneumatic system through the clamp 304 and the clamp 312, causing the gas in the regulating air chamber 400 to flow in the opposite direction through the damping hole 412. The conical structure of the damping hole 412 provides damping force for the gas flow, effectively absorbing the vibration kinetic energy and significantly improving the stability and safety of the test process.

[0030] Example 2: Please refer to Figure 1 - Figure 12 The present invention also provides a technical solution, which differs from the technical solution of Embodiment 1 as follows: a high-voltage AC withstand voltage test device for high-voltage equipment.

[0031] Furthermore, the transformer assembly also includes a hollow push rod 411 fixedly connected to the top of the movable plug 409. The top of the hollow push rod 411 passes through the shift frame 200 and is connected to the positioning plate 315. One end of the flexible hollow tube 300 is slidably connected to a gas-blocking piston rod 308 adapted thereto. One end of the gas-blocking piston rod 308 is fixedly connected to an expansion piston rod 309. One end of the expansion piston rod 309 passes through the auxiliary frame 303 and is fixedly connected to the support plate 305. By setting the piston end of the gas-blocking piston rod 308 to be located inside the flexible hollow tube 300, and at the same time, the regulating gas chamber 400 is connected to the telescopic cylinder 302 through the flexible hollow tube 300, when the gas in the regulating gas chamber 400 is compressed and needs to pass through the flexible hollow tube 300, it will push the piston end of the gas-blocking piston rod 308 to move and drive the support plate 305 to move. When the piston end of the gas-blocking piston rod 308 is pushed out of the telescopic cylinder 302, the gas will enter the interior of the telescopic cylinder 302, causing the telescopic cylinder 302 to expand.

[0032] Furthermore, a rack 208 is fixedly connected inside the fixed frame 201, and a rotating rod 210 is rotatably connected inside the shifting frame 200. A gear 209, which is driven by the rack 208, is fixedly connected to the outer surface of the rotating rod 210. An air delivery impeller housing 405 driven by the rotating rod 210 is provided on the outer surface of the rotating rod 210. The air delivery impeller housing 405 is connected to the air delivery cylinder 402 through a pressurized air pipe 406. By setting the rack 208 and the gear 209 to mesh, the shifting frame 200 can be driven by the gear 209 when sliding on the fixed frame 201. At this time, the rotation of the rotating rod 210 will drive the impeller inside the air delivery impeller housing 405 to rotate and pump the external gas into the air delivery cylinder 402 through the pressurized air pipe 406. At this time, the gas volume in the air delivery cylinder 402 can be increased without starting the cylinder 403, so that the gas flows into the regulating gas chamber 400 through the air delivery pipe 404.

[0033] The system includes two air sources that can operate independently or in tandem: an air impeller housing 405 coupled to the lifting motion, and an independently controlled air pump 401 and cylinder 403. The air impeller housing 405 is connected to an air cylinder 402, which serves as an air storage / buffer unit, via a pressurized air pipe 406. The output end of the cylinder 403 extends into the air cylinder 402, driving the pusher 413 to move and directly change its internal air pressure.

[0034] Simultaneously, the upward movement of the movable stopper 409 also compresses the gas in the upper part of the regulating gas chamber 400, causing it to flow through the flexible air tube 300 to the telescopic cylinder 302. The gas first pushes the piston end of the gas-blocking piston rod 308 to move, driving the expansion piston rod 309 and the support plate 305 to move horizontally. Subsequently, the continuously entering gas causes the cavity of the telescopic cylinder 302 to expand, pushing its outer shell to extend, thereby lifting the auxiliary frame 303 as a whole. The horizontal movement of the support plate 305 is converted into the opposing sliding of the two clamping blocks 304 through the engagement of the limiting rod 306 and the inclined surface of the inclined slide bar 307, so that they hug the cable from both sides to complete the auxiliary support.

[0035] It also includes a heat dissipation mechanism, which uses gas in the adjustable gas chamber 400 to dissipate heat from the cable under test. The heat dissipation mechanism includes an air pump 401 fixedly connected to one side of the transfer frame 200, with the air delivery end of the air pump 401 extending into the adjustable gas chamber 400. A second solenoid valve 410 is installed inside the hollow push rod 411, and the hollow push rod 411 delivers gas to the push plate 314 for discharge through the second solenoid valve 410. A vent hole 310 is opened inside the expansion piston rod 309, and a first solenoid valve 311 is installed inside the vent hole 310. By setting up the heat dissipation mechanism, the test cable can be cooled. The cable is cooled by pumping air into the adjustable air chamber 400 by operating the air pump 401. At the same time, the second solenoid valve 410 is opened to connect the inside of the hollow push rod 411 with the adjustable air chamber 400. The supplied gas passes through the hollow push rod 411 and flows into the push plate 314. Then, it is discharged through the top of the push plate 314 and blown onto the surface of the cable under test. At the same time, the first solenoid valve 311 is opened to connect the air passage 310 with the inside of the telescopic cylinder 302, so that the gas is discharged through the top of the support plate 305. The pumping volume of the air pump 401 can be kept consistent with the exhaust volume of the heat dissipation to stabilize the air pressure.

[0036] Specifically, vibration causes a slight displacement of the pallet 305, compressing the gas inside the telescopic cylinder 302. The gas then impacts the movable plug 409 inside the regulating gas chamber 400 through the flexible hollow tube 300. Alternatively, vibration may directly cause the movable plug 409 to displace through the clamping mechanism. Regardless of the path, the gas between the regulating gas chamber 400 and the gas delivery cylinder 402 is ultimately forced to flow back and forth through the damping orifice 412. Because the damping orifice 412 has a tapered structure that is narrower at the top and wider at the bottom, it significantly throttles and dampes the gas flow, especially when flowing from the regulating gas chamber to the gas delivery cylinder. This converts the kinetic energy of the mechanical vibration into heat energy, effectively suppressing cable vibration. When the gas repeatedly passes through the narrow damping orifice 412, especially when flowing from the narrow end to the wide end, it encounters enormous viscous resistance. This process allows for extremely small piston movements to absorb vibration, but due to the extremely high damping, this movement is strictly limited to a very small amplitude and energy range, and will never lead to macroscopic loosening of the clamp.

[0037] When the cable end or connection point heats up, active cooling can be activated. First, the air pump 401 is turned on to pump additional gas into the regulating air chamber 400 for pressurization. Then, the second solenoid valve 410 installed on the hollow top rod 411 is opened, and the cooling gas in the regulating air chamber 400 flows through the internal channel of the hollow top rod 411 to the upper push plate 314, and finally blows out from the exhaust hole at the top, directly cooling the clamped end of the cable or the adjacent terminal head. At the same time, the first solenoid valve 311 located on the vent hole 310 inside the expansion piston rod 309 can be opened, allowing some of the gas in the telescopic cylinder 302 to flow into the support plate 305 through the vent hole 310 and be discharged from its surface, providing auxiliary air cooling for the middle section of the cable. During this process, the continuous supply of gas also provides stable pressure for the gas-blocking piston rod 308, maintaining a constant supporting force.

[0038] In summary, the operator only needs to control the lifting and lowering of the shifter 200 to adapt to the cable position. This action is automatically converted into pneumatic power to drive the entire clamping and support system. Gas enters the regulating air chamber 400 through the damping hole 412, pushing the movable plug 409 and the hollow push rod 411 to precisely close the clamp 312. At the same time, the clamping block 304 adaptively tightens through the flexible hollow tube 300 and the telescopic cylinder 302. Any vibration energy of the cable is captured by the expansion piston rod 309 and other structures, and converted into the reciprocating flow of gas between the regulating air chamber 400 and the air delivery cylinder 402. When the gas flows through the specially designed conical damping hole 412, it generates strong damping, efficiently dissipates kinetic energy, and significantly suppresses cable vibration. This not only protects the cable and the device, but more importantly, it greatly reduces the interference of vibration on weak partial discharge signals and improves diagnostic sensitivity. At the same time, the heat dissipation mechanism integrating the air pump 401 and the second solenoid valve 410 can guide the cooling gas directly to the cable surface at the push plate 314 and the support plate 305.

[0039] It should be noted that the upward movement of the shifter 200 to drive the gear 209 to rotate and drive the air delivery impeller housing 405 is an auxiliary design. It is a pre-positioning of the cable to be tested. Its air delivery volume is small and can only drive the clamping components to close slightly. The subsequent clamping action of the clamping components is completed by the cylinder 403 driving the pusher 413 to move upward to further compress the gas in the air delivery cylinder 402.

[0040] Example 3: Please refer to Figure 1 - Figure 12 The present invention also provides a technical solution, which differs from the technical solution of Embodiment 1 as follows: a high-voltage AC withstand voltage test method for high-voltage equipment, comprising the following steps: S1. Place the cable: Place the end of the cable to be tested between the two clamps 312, with the lower part of the cable resting on the auxiliary frame 303; S2. Adjusting the height: Operate the lifting assembly to drive the moving frame 200 to rise or fall to a predetermined height; S3. Linkage and fixing: During the lifting and lowering process of the moving frame 200, gas is pumped into the regulating air chamber 400 by driving the transformer assembly to control the clamping action of the clamping plate 312 and the clamping block 304. S4. Connect the test circuit: Connect the frequency converter 100 to the cable under test through the test mechanism, set the test parameters and conduct the test; S5. Perform the test and suppress vibration: Start the variable frequency power supply 100 to perform a withstand voltage test. The vibration generated by the cable is transmitted to the transformer assembly through the clamping assembly and the auxiliary assembly and is consumed by the airflow damping in the adjustable air chamber 400.

[0041] The specific steps are as follows: 1. Cable placement: When in use, one end of the cable to be tested is fixed in the two clamps 312, and the lower surface of the cable is placed on the auxiliary frame 303, so that the auxiliary frame 303 provides auxiliary support for the cable. 2. Perform the test: Then connect the frequency converter 100 to the excitation transformer 101, and the excitation transformer 101 to the high-voltage reactor 103. Then connect the high-voltage reactor 103 to the cable under test. Connect the high-voltage end of the capacitor voltage divider 104 in parallel with the cable under test. Connect the low-voltage signal line of the capacitor voltage divider 104 back to the main frequency converter 100. Set the target test voltage, withstand voltage time, overvoltage and overcurrent protection values ​​and other parameters on the frequency converter 100. 3. Adjusting the height: Since the cable laying positions on site are at different heights, the position of the clamp 312 and the auxiliary frame 303 can be changed by adjusting the height of the moving frame 200. This ensures that the spatial position of the cable relative to the ground and other objects is fixed, so that parameters such as capacitance to ground and stray capacitance are consistent in each test. At the same time, it avoids damage to the cable terminal due to improper force or damage to the insulation due to friction and compression. The double-head motor 202 can be turned to drive the lead screw 203 to rotate. The lead screw 203 will drive the moving block 205 to rotate, which will cause one end of the crank 206 to tilt. This will cause the other end of the crank 206 to push the hinge seat 207 to move, and finally make the moving frame 200 slide and move upward within the fixed frame 201. 4. Linkage and Fixing: When the moving frame 200 moves relative to the fixed frame 201, the gear 209 will abut against the rack 208, driving the rotating rod 210 to rotate. At this time, the rotating rod 210 will drive the impeller inside the air delivery impeller housing 405 to rotate, thus delivering external air through the pressurized air pipe 406 to the inside of the air delivery cylinder 402. At this time, the gas in the air delivery cylinder 402 increases and will pass through the air delivery pipe 404 and multiple damping holes 412 before entering the bottom of the regulating air chamber 400, thereby pushing the movable plug 409 to move upward. At this time, the movable plug 409 moves upward, pushing the hollow push rod 411 to move upward. At this time, the hollow push rod 411 moves upward, which will drive the positioning plate 315 and its top push plate 314 to move. The push plate 314 will engage with the rocker arm. One end of plate 313 abuts against the rocker 313, thereby driving the rocker 313 to flip and causing the two clamping plates 312 to come closer together and clamp and fix the cable to be tested. As the movable plug 409 moves upward, it compresses the gas in the regulating gas chamber 400 and delivers it to the inside of the telescopic cylinder 302 through the flexible tube 300. At this time, the gas enters the telescopic cylinder 302 through the flexible tube 300 and pushes the piston end of the gas-blocking piston rod 308 to move, thereby pushing the support plate 305 to move. The support plate 305 will drive one end of the limiting rod 306 to slide in the inclined slide bar 307. At this time, the inclined slide bar 307 is constructed of an inclined surface and will drive the clamping block 304 to move closer together under the traction force of the limiting rod 306, thereby providing auxiliary support for the cable. 5. Height adjustment: When the travel of the moving frame 200 is insufficient or the height adjustment is not required, the cylinder 403 can be operated to move the cylinder 403 in the air supply cylinder 402, so that the gas in the air supply cylinder 402 flows into the volume adjustment air chamber 400 through the air supply pipe 404, thereby driving the movable plug 409. 6. Vibration Suppression: When the cable under test vibrates, its resonant force will be transmitted through the clamping block 304 and the clamping plate 312 respectively. Under the action of force transmission, the gas in the flexible tube 300 will flow and squeeze the movable plug 409 to reset. At the same time, an expansion piston rod 309 is set inside the telescopic cylinder 302. When the support plate 305 is reset by the vibration force, it will squeeze the gas in the telescopic cylinder 302. The gas flows in the adjustable gas chamber 400 and transmits kinetic energy to the movable plug 409, so that the movable plug 409 is pressed down and the gas at its bottom is squeezed back to the gas delivery cylinder 402 through the damping hole 412. Since the damping hole 412 is designed with a narrow upper and wide lower structure, it can effectively increase the damping force for the gas flow, thereby suppressing the kinetic energy generated by vibration. At the same time, the position of the push plug 413 can be continuously adjusted to provide a stronger torque for the clamping block 304 and the clamping plate 312. 7. Selective heat dissipation: When the cable under test generates heat, the air pump 401 can be turned on to increase the air volume inside the adjustable air chamber 400. At the same time, the second solenoid valve 410 can be turned on to allow the gas in the adjustable air chamber 400 to be transported to the inside of the push plate 314 through the hollow push rod 411, and then discharged through the through hole at the top of the push plate 314 to dissipate heat from the end face of the cable under test. At the same time, when the gas in the adjustable air chamber 400 increases, it will be discharged into the telescopic cylinder 302 through the flexible hollow tube 300. The first solenoid valve 311 is turned on to allow the gas in the telescopic cylinder 302 to be transported into the support plate 305 through the air passage 310, and then discharged. At the same time, when the gas in the flexible hollow tube 300 enters the telescopic cylinder 302, it will generate a continuous thrust. This thrust can continuously push the piston end of the air-blocking piston rod 308 to move, thereby providing stable support for the support plate 305.

[0042] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, 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.

[0043] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-voltage AC withstand voltage test device for high-voltage equipment, comprising a frequency converter (100) and a test mechanism connected between the frequency converter (100) and the cable under test, characterized in that, Also includes: The lifting assembly includes a fixed frame (201) and a sliding frame (200) that slides relative to the fixed frame (201). The clamping assembly includes a clamping piece (312) located on top of the shifter (200) and disposed opposite to it. An auxiliary component includes an auxiliary frame (303) disposed on one side of the transfer frame (200), the auxiliary frame (303) being used to support the cable from below, and a clamping block (304) being slidably connected to the top of the auxiliary frame (303). The linkage system includes a regulating air chamber (400) disposed in the shift frame (200), wherein a pressure changing component is disposed in the regulating air chamber (400) to change its own pressure, the pressure changing component is used to control the clamping action of the clamping plate (312) and the clamping block (304), and the pressure changing component uses the airflow damping in the regulating air chamber (400) to suppress the vibration of the cable under test.

2. The high-voltage AC withstand voltage test device for high-voltage equipment according to claim 1, characterized in that: The lifting assembly also includes a dual-head motor (202) installed at the bottom of the fixed frame (201), a lead screw (203) driven by the dual-head motor (202), a moving block (205) threadedly engaged with the lead screw (203), a hinge seat (207) fixedly connected to the side of the moving frame (200), and a crank (206) rotatably connected between the moving block (205) and the hinge seat (207). A slide rail (204) for sliding connection of the moving block (205) is fixedly connected to the side of the fixed frame (201).

3. The high-voltage AC withstand voltage test device for high-voltage equipment according to claim 1, characterized in that: The clamping assembly is also rotatably connected to a rocker (313) inside the shift frame (200). One end of the rocker (313) is fixedly connected to one end of the clamp (312). A positioning plate (315) is slidably connected inside the shift frame (200). A push plate (314) for abutting the bottom of the rocker (313) is fixedly connected to the top of the positioning plate (315).

4. The high-voltage AC withstand voltage test device for high-voltage equipment according to claim 3, characterized in that: The auxiliary component also includes a flexible hollow tube (300) fixedly connected to the side of the transfer frame (200). One end of the flexible hollow tube (300) is fixedly connected to a telescopic cylinder (302) for supporting the auxiliary frame (303). The auxiliary frame (303) is provided with a support plate (305). Limiting rods (306) are fixedly connected to both sides of the support plate (305). An inclined slide bar (307) is fixedly connected to the side of the clamping block (304). The limiting rod (306) and the inclined slide bar (307) are slidably connected.

5. The high-voltage AC withstand voltage test device for high-voltage equipment according to claim 4, characterized in that: The transformer assembly includes an air cylinder (402) disposed in a transfer frame (200). The top of the air cylinder (402) is connected to the interior of the regulating air chamber (400) via an air pipe (404). The interior of the air pipe (404) is provided with multiple damping holes (412). The bottom of the air cylinder (402) is fixedly connected to a cylinder (403). The output end of the cylinder (403) extends into the air cylinder (402) and is fixedly connected to a push plug (413). The interior of the regulating air chamber (400) is slidably connected to a movable plug (409).

6. The high-voltage AC withstand voltage test device for high-voltage equipment according to claim 5, characterized in that: The transformer assembly also includes a hollow top rod (411) fixedly connected to the top of the movable plug (409). The top of the hollow top rod (411) passes through the shift frame (200) and is connected to the positioning plate (315). One end of the flexible hollow tube (300) is slidably connected to a gas-blocking piston rod (308) adapted thereto. One end of the gas-blocking piston rod (308) is fixedly connected to an expansion piston rod (309). One end of the expansion piston rod (309) passes through the auxiliary frame (303) and is fixedly connected to the support plate (305).

7. The high-voltage AC withstand voltage test device for high-voltage equipment according to claim 5, characterized in that: The fixed frame (201) is internally fixedly connected to a rack (208), and the moving frame (200) is internally rotatably connected to a rotating rod (210). The outer surface of the rotating rod (210) is fixedly connected to a gear (209) that is connected to the rack (208) for transmission. The outer surface of the rotating rod (210) is provided with an air conveying impeller housing (405) driven by the rotating rod (210). The air conveying impeller housing (405) is connected to the air conveying cylinder (402) through a pressurized air pipe (406).

8. The high-voltage AC withstand voltage test device for high-voltage equipment according to claim 6, characterized in that: It also includes a heat dissipation mechanism, which uses gas in the adjustable gas chamber (400) to dissipate heat from the cable to be tested. The heat dissipation mechanism includes an air pump (401) fixedly connected to one side of the transfer frame (200). The air pump (401) extends into the adjustable gas chamber (400). A second solenoid valve (410) is installed inside the hollow push rod (411). The hollow push rod (411) delivers gas to the push plate (314) through the second solenoid valve (410) for discharge.

9. The high-voltage AC withstand voltage test device for high-voltage equipment according to claim 1, characterized in that: The test mechanism includes an excitation transformer (101), a high-voltage reactor (103), and a capacitor voltage divider (104). The excitation transformer (101) is connected between the frequency converter (100) and the high-voltage reactor (103). The high-voltage end of the capacitor voltage divider (104) is used to connect in parallel with the cable under test, and the low-voltage signal line is connected back to the frequency converter (100).

10. A method for high-voltage AC withstand voltage test of high-voltage equipment, comprising the high-voltage AC withstand voltage test apparatus for high-voltage equipment according to any one of claims 1-9, characterized in that, Includes the following steps: S1. Place the cable: Place the end of the cable to be tested between the two clamps (312), with the lower part of the cable resting on the auxiliary frame (303); S2. Adjusting the height: Operate the lifting assembly to drive the moving frame (200) to rise or fall to a predetermined height; S3. Linkage fixing: During the lifting and lowering process of the moving frame (200), gas is pumped into the regulating air chamber (400) by driving the transformer assembly to control the clamping action of the clamping plate (312) and the clamping block (304); S4. Connect the test circuit: Connect the frequency converter (100) to the cable under test through the test mechanism, set the test parameters and conduct the test; S5. Perform test and suppress vibration: Start the variable frequency power supply (100) to perform a withstand voltage test. The vibration generated by the cable is transmitted to the transformer assembly through the clamping assembly and the auxiliary assembly and is consumed by the airflow damping in the regulating air chamber (400).

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