Dry-type transformer partial discharge detection device

Abstract

The application relates to a dry-type transformer partial discharge detection device, and belongs to the field of transformer detection devices. The device comprises an intelligent large transformer main body and multiple groups of discharge detection units arranged on the intelligent large transformer main body. The multiple groups of discharge detection units are respectively located at high-voltage connection terminals of the intelligent large transformer main body. The discharge detection unit comprises a support, a detection needle and an indicator lamp. The support is arranged on the intelligent large transformer main body. The indicator lamp is arranged on the support. The detection needle is arranged on the support. One end of the detection needle is opposite to the high-voltage connection terminal. The other end of the detection needle is connected with the indicator lamp in series through an electric wire. A subsidy unit is slidably arranged on the support. The subsidy unit is used for subsidizing an insulating rubber pad to the high-voltage connection terminal. The application has the technical effects of quick discharge detection response and high safety.

Description

Technical Field

[0001] This application relates to the technical field of transformer testing devices, and in particular to a partial discharge testing device for dry-type transformers. Background Technology

[0002] Dry-type transformers are core equipment in power systems. Their high-voltage terminals are under high-voltage conditions for a long time, which can easily lead to partial discharge due to insulation aging, dirt accumulation, abnormal electric field distribution, etc. Partial discharge is a major precursor to insulation deterioration and equipment breakdown, which can accelerate component aging and even cause short circuits and safety accidents, seriously threatening the stable operation of the power system.

[0003] Current traditional partial discharge detection methods suffer from response lag and can only detect faults, failing to provide timely temporary sealing of the discharge site, leading to fault propagation and posing significant safety hazards to maintenance personnel. Furthermore, the need for simultaneous detection of multiple high-voltage terminals is difficult to meet, resulting in low maintenance efficiency.

[0004] Regarding the aforementioned technologies, the inventors believe that existing partial discharge detection equipment suffers from slow detection response and safety hazards during maintenance. Summary of the Invention

[0005] To address the aforementioned technical problems, this application provides a partial discharge detection device for dry-type transformers.

[0006] This application provides a partial discharge detection device for dry-type transformers, which adopts the following technical solution: A partial discharge detection device for a dry-type transformer includes a smart large transformer body and multiple sets of discharge detection units disposed on the smart large transformer body; the multiple sets of discharge detection units are respectively located at the high-voltage terminals of the smart large transformer body; each discharge detection unit includes a bracket, a detection needle, and an indicator light; the bracket is disposed on the smart large transformer body; the indicator light is disposed on the bracket; the detection needle is disposed on the bracket; one end of the detection needle is directly opposite the high-voltage terminal; the other end of the detection needle is connected in series with the indicator light via a wire; a subsidy unit is slidably disposed on the bracket; the subsidy unit is used to apply an insulating rubber pad to the high-voltage terminal.

[0007] By adopting the above technical solution, when partial discharge or leakage occurs at the high-voltage terminal, the detection pin connects to the leakage current, the series circuit is connected, and the indicator light illuminates, which can quickly identify the fault and respond to the partial discharge or leakage signal of the high-voltage terminal in real time. At the same time, the subsidy unit on the bracket can promptly apply insulating rubber pads to the high-voltage terminal, quickly curb the spread of the fault, achieve temporary sealing of the fault, and reduce safety risks.

[0008] Preferably, the subsidy unit includes a drive rod, a compression plate, and a heating plate; the drive rod is slidably mounted on the bracket; the compression plate is located at one end of the drive rod near the high-voltage terminal; the compression plate is provided with a wrapping unit; an insulating pad is provided on the wrapping unit; the heating plate is mounted on the bracket; the heating plate is connected in series with the detection needle and the indicator light via wires; a subsidy opening is provided on the heating plate; the sidewall of the insulating pad is attached to the heating plate and located at the subsidy opening.

[0009] By adopting the above technical solution, when the indicator light illuminates to indicate a fault, the heating plate is activated simultaneously to heat and soften the insulating pad. This, combined with the wrapping unit, makes the insulating pad fit the high-voltage terminal more closely, improving the temporary sealing effect and better preventing the spread of the fault.

[0010] Preferably, the subsidy unit further includes a compression spring; the compression spring is sleeved on the drive rod and located between the compression plate and the bracket; the compression spring is used to provide a force to bring the compression plate close to the high-voltage terminal.

[0011] By adopting the above technical solution, during normal transformer operation, the compression spring pushes the compression plate to move the wrapping unit, causing the insulating rubber pad to adhere to the heating plate and seal the subsidy port, ensuring the subsidy unit is stable and ready for operation. After the insulating rubber pad softens due to heat, the compression spring releases its pre-tightening force, providing a thrust to the compression plate near the high-voltage terminal, pushing the drive rod to slide along the bracket, moving the compression plate and wrapping unit, and applying the insulating rubber pad through the subsidy port to the high-voltage terminal, achieving temporary sealing during faults. This integrates the detection, heating, and automatic pushing of the insulating rubber pad for subsidy, requiring no additional power and providing a faster response. The compression spring, fitted onto the drive rod, is easy to install and provides uniform force, ensuring stable positioning of the insulating rubber pad under normal conditions and providing continuous thrust during faults, thus improving the stability of the subsidy unit's operation.

[0012] Preferably, the packaging unit includes a flexible airbag; the flexible airbag is disposed on the extrusion plate; and the insulating pad is disposed on the flexible airbag.

[0013] By adopting the above technical solution, the packaging unit uses a flexible airbag that can flexibly deform according to the contour of the high-voltage terminal, so that the softened insulating pad fits the terminal surface in all directions, improving the sealing effect and better curbing the spread of discharge and leakage faults; the flexible airbag is soft in texture, which can avoid wear on the high-voltage terminal during the patching process, while buffering the squeezing force to prevent the insulating pad from breaking and ensure the reliability of patching.

[0014] Preferably, the inner and outer walls of the flexible airbag are respectively covered with heat-resistant layers.

[0015] By adopting the above technical solution, the heat-resistant layer of the inner and outer walls of the flexible airbag can effectively isolate the high temperature of the heating plate, prevent the flexible airbag from aging and breaking due to high temperature, extend the service life of the flexible airbag, and ensure the long-term stable operation of the subsidy unit.

[0016] Preferably, the packaging unit further includes a compression tube; the compression tube is sleeved on the compression plate; one end of the compression tube abuts against the flexible airbag.

[0017] By adopting the above technical solution, the extrusion tube and the flexible airbag abut against each other, which can apply a continuous abutment force during the patching process, pushing the flexible airbag to fully fit the contour of the high-voltage terminal, avoiding gaps between the insulating rubber pad and the terminal, greatly improving the sealing effect, and better curbing the spread of discharge and leakage faults; the extrusion tube plays an auxiliary role in fixing and pressurizing the flexible airbag, preventing the flexible airbag from shifting or deforming excessively during the patching process, ensuring that the insulating rubber pad is accurately patched to the corresponding position of the terminal, and ensuring the reliability of the insulating rubber pad patching.

[0018] Preferably, the end of the extrusion tube away from the flexible airbag is connected to two sliding rods; the bracket has two sliding holes; the two sliding rods are slidably disposed in the two sliding holes respectively; the drive rod is provided with a drive unit; the power output end of the drive unit is connected to the two sliding rods.

[0019] By adopting the above technical solution, the drive unit can drive the extrusion tube to move smoothly through the cooperation of the two sliding rods and the sliding hole, and apply a uniform contact force to the flexible airbag, so as to avoid uneven local force and cause the insulating rubber pad to not fit tightly, thus improving the sealing effect. The sliding cooperation of the sliding rod and the sliding hole guides the extrusion tube, prevents the extrusion tube from deviating, and ensures that the extrusion tube is always aligned with the flexible airbag to apply force, ensuring that the insulating rubber pad is accurately attached to the corresponding position of the high voltage terminal.

[0020] Preferably, the drive unit includes a connector and two drive housings; the two drive housings are respectively disposed on the drive rod; a piston is respectively disposed at one end of the two slide rods; the two pistons are respectively located inside the two drive housings; the connector is disposed on the drive rod; an air cavity is formed in the connector; the air cavity communicates with the interior of the two drive housings; an air hole is formed on the drive rod along its axial direction; the air cavity, the air hole and the interior of the flexible airbag are sequentially connected.

[0021] By adopting the above technical solution, the internal air pressure of the flexible airbag increases after heating, and is transmitted to the two drive housings through air holes and air chambers. No additional power source is required, realizing the integration of heating, pressurization and driving extrusion processes. The transmission is smooth and the response is timely. Moreover, the extrusion force can be automatically adapted to the air pressure to avoid excessive extrusion and damage to components. The two drive housings, piston and slide rod cooperate accordingly. The air chamber evenly distributes the air pressure to the two drive housings, pushing the slide rod to move synchronously, driving the extrusion tube to apply a uniform contact force to the flexible airbag, ensuring that the insulating rubber gasket fits tightly to the high-voltage terminal in all directions, greatly improving the sealing effect.

[0022] Preferably, a return spring is sleeved on the slide rod; the return spring is located between the piston and the drive housing; the return spring is used to provide a force to move the piston away from the flexible airbag.

[0023] By adopting the above technical solution, under normal conditions, the return spring pushes the piston and slide rod away from the flexible airbag, keeping the extrusion tube in its initial position. This prevents the extrusion tube from accidentally extruding the flexible airbag and causing the insulating pad to shift, ensuring that the insulating pad is stably attached to the heating plate. The elastic force of the return spring can be balanced with the air pressure thrust, ensuring that the air pressure thrust can smoothly push the slide rod and extrusion tube to achieve extrusion and compensation in case of failure, while avoiding excessive extrusion due to excessive air pressure. This protects the flexible airbag, insulating pad, and terminals from damage and improves the operational safety of the device.

[0024] Preferably, the insulating pad is provided with an annular adhesive element.

[0025] By adopting the above technical solution, the annular adhesive component can make the insulating pad fit tightly against the surface of the high-voltage terminal block, and at the same time adhere to the mating part of the insulating pad itself, avoiding gaps, effectively curbing the spread of partial discharge and leakage, and improving the reliability of temporary sealing; the annular adhesive component can fix the position of the insulating pad, preventing the insulating pad from shifting or falling off due to transformer vibration, external force, etc. after patching, ensuring the continuous and stable sealing effect, and buying enough time for maintenance.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. When partial discharge or leakage occurs at the high-voltage terminal, the detection probe draws the leakage current, the series circuit is connected, and the indicator light illuminates, which can quickly identify the fault and respond to the partial discharge or leakage signal of the high-voltage terminal in real time. At the same time, the subsidy unit on the bracket can promptly apply insulating rubber pads to the high-voltage terminal to quickly curb the spread of the fault, achieve temporary sealing of the fault, and reduce safety risks.

[0027] 2. When the indicator light illuminates to indicate a fault, the heating plate simultaneously activates, heating and softening the insulating pad. This, combined with the wrapping unit, ensures the insulating pad fits more closely to the high-voltage terminal, improving the temporary seal and better preventing the fault from spreading. After the insulating pad softens from the heat, the compression spring releases its pre-tightening force, providing a thrust to the compression plate as it approaches the high-voltage terminal. This pushes the drive rod along the bracket, moving the compression plate and wrapping unit to attach the insulating pad through the patching port to the high-voltage terminal, achieving a temporary seal. This integrates detection, heating, and automatic pad application, requiring no additional power and providing a faster response. The compression spring, fitted onto the drive rod, is easy to install and distributes force evenly, ensuring stable positioning of the insulating pad under normal conditions and providing continuous thrust during faults, thus improving the stability of the patching unit's operation.

[0028] 3. The extrusion tube abuts against the flexible airbag, applying a continuous contact force during the patching process. This pushes the flexible airbag to fully conform to the contour of the high-voltage terminal, preventing gaps between the insulating pad and the terminal, significantly improving the sealing effect, and better curbing the spread of discharge and leakage faults. The extrusion tube also assists in fixing and pressurizing the flexible airbag, preventing it from shifting or deforming excessively during the patching process. This ensures that the insulating pad is accurately patched to the corresponding position of the terminal, guaranteeing the reliability of the patching process. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of a partial discharge detection device for dry-type transformers.

[0030] Figure 2 yes Figure 1 A magnified view of part A in the image.

[0031] Figure 3 This is a schematic diagram of the insulating pad structure in the embodiment.

[0032] Figure 4 This is a schematic diagram of the heating plate in the embodiment.

[0033] Figure 5 This is a schematic diagram of the packaging unit in the embodiment.

[0034] Figure 6 This is a schematic diagram of the structure of the subsidy unit in the embodiment.

[0035] Figure 7 This is a schematic diagram of the fan structure in the embodiment.

[0036] Figure 8 yes Figure 7 A magnified view of part B in the image.

[0037] Explanation of reference numerals in the attached figures: 1. Intelligent large transformer body; 11. High voltage terminal; 2. Discharge detection unit; 21. Bracket; 22. Detection needle; 23. Indicator light; 3. Subsiding unit; 31. Drive rod; 311. Air hole; 32. Extrusion plate; 33. Heating plate; 331. Subsiding port; 34. Extrusion spring; 4. Insulating pad; 41. Annular adhesive component; 5. Wrapping unit; 51. Flexible airbag; 52. Extrusion tube; 6. Slide rod; 61. Piston; 62. Return spring; 7. Drive unit; 71. Connector; 711. Air chamber; 72. Drive housing; 8. Fan; 81. Electromagnet; 82. Iron plate; 83. Switch. Detailed Implementation

[0038] The following is in conjunction with the appendix Figure 1-8 This application will be described in further detail.

[0039] This application discloses a partial discharge detection device for a dry-type transformer. (Refer to...) Figure 1-3 The system includes a main body 1 of an intelligent large transformer and multiple sets of discharge detection units 2 installed on the main body 1. The multiple sets of discharge detection units 2 are located at the high-voltage terminals 11 of the main body 1. Each discharge detection unit 2 includes a bracket 21, a detection needle 22, and an indicator light 23. The bracket 21 is installed on the main body 1. The indicator light 23 and the detection needle 22 are both installed on the bracket 21. One end of the detection needle 22 is directly opposite the high-voltage terminal 11. The other end is connected in series with the indicator light 23 via a wire. The detection needle 22 can be an iron needle or a copper needle. When the main body 1 of the intelligent large transformer is running normally and stably, the electric field of its high-voltage terminal 11 is in a safe and stable state, and there is no abnormal partial discharge phenomenon. At this time, no induced leakage current is generated around the detection needle 22, and the series circuit formed by the detection needle 22 and the indicator light 23 is in an open circuit state, and the indicator light 23 remains off.

[0040] When the insulation at the high-voltage terminal 11 ages, breaks, becomes contaminated, or experiences abnormal electric field distribution, causing partial discharge or leakage at the terminal, a weak stray high-voltage current will leak out. The detection pin 22, positioned directly opposite the terminal 11, can sense and receive the leaked discharge current. The current is transmitted to the indicator light 23 via the connecting wire, forming a complete closed conductive circuit with the detection pin 22, the wire, and the indicator light 23. Once the circuit is complete, the indicator light 23 immediately illuminates, clearly alerting on-site maintenance personnel to the presence of partial discharge or leakage at the high-voltage terminal 11, facilitating timely troubleshooting and handling of potential hazards. To prevent current from being conducted to the bracket 21, a layer of insulating rubber is wrapped around the outside of the detection pin 22, connecting it to the bracket 21. The insulating rubber layer effectively isolates the detection pin 22 from the metal bracket 21, preventing the abnormal discharge current from being conducted and diffused to the bracket 21, thus avoiding the risk of electric shock caused by the bracket becoming energized.

[0041] Reference Figures 1 to 6 A subsidy unit 3 is slidably mounted on the bracket 21; the subsidy unit 3 is used to apply an insulating rubber pad 4 to the high-voltage terminal 11. Specifically, the subsidy unit 3 includes a drive rod 31, a compression spring 34, a compression plate 32, and a heating plate 33; the drive rod 31 is slidably mounted on the bracket 21; the compression plate 32 is located at one end of the drive rod 31 near the high-voltage terminal 11; a wrapping unit 5 is provided on the compression plate 32; the insulating rubber pad 4 is located on the wrapping unit 5; the heating plate 33 is located on the bracket 21; the heating plate 33 is connected in series with the detection needle 22 and the indicator light 23 via wires; a subsidy opening 331 is opened on the heating plate 33; the subsidy opening 331 is directly opposite the high-voltage terminal 11 of the intelligent large transformer body 1; the side wall of the insulating rubber pad 4 is attached to the heating plate 33 and located at the subsidy opening 331; the compression spring 34 is sleeved on the drive rod 31 and located between the compression plate 32 and the bracket 21; the compression spring 34 is used to provide force for the compression plate 32 to approach the high-voltage terminal 11.

[0042] Under normal circumstances, the insulating pad 4 maintains its original solid state. The compression spring 34 pushes the compression plate 32 and the drive rod 31, and the insulating pad 4 is tightly attached to the heating plate 33 through the wrapping unit 5, and the patch opening 331 is sealed.

[0043] When the detection needle 22 is energized, the heating plate 33 is energized; the heating plate 33 heats the insulating pad 4, which is made of ethylene propylene rubber; the insulating pad 4 is heated to 100-110°C and softens and deforms significantly; using the elastic potential energy of the compression spring 34, a continuous pushing force is applied to the compression plate 32 toward the high-voltage terminal 11, and the drive rod 31 slides toward the high-voltage terminal 11, causing the compression plate 32 fixed at the end of the drive rod 31 to move synchronously. At this time, the softened insulating pad 4 no longer has sufficient rigidity to resist the pushing force of the compression plate 32; the compression plate 32, driven by the pushing force of the compression spring 34, will drive the wrapping unit 5 and the softened insulating pad 4 to continue moving toward the high-voltage terminal 11. Since the subsidy port 331 is directly opposite the high-voltage terminal 11 and the insulating pad 4 is located at the subsidy port 331, under the continuous action of the thrust, the softened insulating pad 4 will pass smoothly through the subsidy port 331. When the insulating pad 4 comes into contact with the high-voltage terminal 11, the wrapping unit 5 will conform to the outer contour of the high-voltage terminal 11 with the deformation of the insulating pad 4, wrapping the softened insulating pad 4 on the surface of the high-voltage terminal 11, thereby sealing the fault location of leakage and partial discharge, and playing a role in temporary covering and isolation.

[0044] Reference Figure 3 To improve the sealing performance of the insulating pad 4, an annular adhesive element 41 is provided on the insulating pad 4. The annular adhesive element 41 is an annular unvulcanized raw rubber. The annular adhesive element 41 becomes sticky when heated. After the wrapping unit 5 wraps the insulating pad 4 around the high-voltage terminal 11, the annular adhesive element 41 will tightly adhere to the joint of the insulating pad 4 and the contact surface between the insulating pad 4 and the high-voltage terminal 11, firmly adhering all parts of the wrapped insulating pad 4 together. At the same time, it enhances the tightness of the adhesion between the insulating pad 4 and the surface of the high-voltage terminal 11, further improving the sealing effect and ensuring more reliable coverage of the leakage point. This provides sufficient time for maintenance personnel to troubleshoot and thoroughly handle the subsequent faults.

[0045] Reference Figure 1 , Figure 2 , Figure 3 , Figure 7 and Figure 8To improve the sealing effect of the insulating gasket 4, a fan 8 can be installed at the high-voltage terminal 11. The fan 8 has a power supply. An electromagnet 81 is installed on the fan 8. The positive and negative poles of the electromagnet 81 are electrically connected to the detection needle 22 through wires to form a circuit. An iron plate 82 is slidably installed on the bracket 21. When the detection needle 22 is energized, the electromagnet 81 is activated. The electromagnet 81 quickly generates magnetism after being energized. Since the iron plate 82 is slidably installed on the bracket 21 and corresponds to the position of the electromagnet 81, the magnetic electromagnet 81 will immediately generate an attraction force, attracting the iron plate 82 towards the electromagnet 81, causing the iron plate 82 to slide. During the sliding process of the iron plate 82, its end will toggle the power switch 83, which will start the power supply and begin supplying power to the fan 8. After the fan 8 is powered on, it will start to rotate immediately, and the air outlet will be aimed at the high-voltage terminal 11. The airflow will blow towards the softened insulating pad 4 attached to the surface of the high-voltage terminal 11, which will carry away the heat on the surface of the insulating pad 4 and accelerate the cooling speed of the insulating pad 4. This will cause the softened insulating pad 4 to solidify and harden in a short time, thereby sealing the high-voltage terminal 11 and further curbing the spread of leakage and discharge. The power supply can also be connected to the alarm, and the alarm will be activated when the power is turned on.

[0046] It should be noted that indicator light 23 is directly driven by the discharge current between the detection needle 22 and the high-voltage terminal 11. It only illuminates when there is discharge or leakage at the high-voltage terminal 11 and the detection circuit is open, serving as a real-time signal that the high-voltage terminal 11 is discharging. The alarm, on the other hand, is powered by a power source. Power activation requires the electromagnet 81 to attract the iron plate 82 and the toggle switch 83 to be activated. Alarm activation only indicates that the high-voltage terminal 11 has exhibited leakage characteristics and that the compensation unit 3 has initiated compensation operations. Once the insulating pad 4 cools and solidifies, completely sealing the high-voltage terminal 11, the discharge is suppressed, the detection needle 22 can no longer draw leakage current, and the detection circuit is disconnected. At this point, indicator light 23 automatically turns off. The closure of indicator light 23 indicates that the discharge of the high-voltage terminal 11 has been temporarily controlled, the sealing effect is effective, and maintenance personnel can safely troubleshoot and repair the high-voltage terminal 11 at this time, avoiding the safety risks of encountering live discharge during maintenance.

[0047] The packaging unit 5 includes a flexible airbag 51 and a compression tube 52; the flexible airbag 51 is mounted on the compression plate 32; an insulating pad 4 is mounted on the flexible airbag 51; the compression tube 52 is sleeved on the compression plate 32; one end of the compression tube 52 abuts against the flexible airbag 51; two sliding rods 6 are connected to the end of the compression tube 52 away from the flexible airbag 51; two sliding holes are opened on the bracket 21; the two sliding rods 6 are slidably mounted in the two sliding holes respectively; a drive unit 7 is mounted on the drive rod 31; the power output end of the drive unit 7 is connected to the two sliding rods 6; when the insulating pad 4 abuts against the high-voltage terminal 11; under the push of the compression plate 32, the middle of the flexible airbag 51 is resisted by the high-voltage terminal 11. The push of the baffle and the extrusion plate 32 prevents the middle part from moving further, causing its periphery to protrude and deform outward. This causes the insulating pad 4 on the surface to extend synchronously to the outer periphery of the high-voltage terminal 11, initially wrapping the insulating pad 4 around the surface of the high-voltage terminal 11 to achieve a preliminary seal. At the same time, the drive unit 7 can push the two slide rods 6, thereby driving the extrusion tube 52 to uniformly extrude the periphery of the flexible airbag 51, pushing the flexible airbag 51 to fit tightly against the outer periphery of the high-voltage terminal 11, making the insulating pad 4 fit more tightly against the surface of the high-voltage terminal 11, and pressing the edges of the insulating pad 4 to ensure that the flexible airbag 51 firmly wraps the insulating pad 4 around the high-voltage terminal 11.

[0048] The flexible airbag 51 can be made of nitrile rubber, which has the characteristics of high air pressure resistance, good elasticity, aging resistance, and resistance to repeated compression deformation. Heat-resistant layers are laid on the inner and outer walls of the flexible airbag 51. The heat-resistant layer is made of EPDM insulating heat-resistant rubber. Under normal conditions, the heat-resistant layer provides effective support for the flexible airbag 51. When heated, it gradually softens and no longer maintains a rigid support state. It can deform synchronously with the deformation of the flexible airbag 51 and, together with the extrusion tube 52, wraps the insulating pad 4, while continuing to play a heat-resistant role and preventing the flexible airbag 51 from being damaged by the high temperature of the heating plate 33.

[0049] The drive unit 7 includes a connector 71 and two drive housings 72; the two drive housings 72 are respectively mounted on the drive rod 31; one end of each of the two slide rods 6 is provided with a piston 61; the two pistons 61 are respectively located inside the two drive housings 72; the connector 71 is mounted on the drive rod 31; the drive unit 7 starts working synchronously as the flexible airbag 51 is initially wrapped. When the heating plate 33 works, the heat generated can be transferred to the flexible airbag 51, causing the air inside the flexible airbag 51 to expand due to heat, and the internal air pressure gradually increases; an air cavity 711 is opened in the connector 71; the air cavity 711 is connected to the interior of the two drive housings 72; an air hole 311 is opened along its axial direction on the drive rod 31; the air cavity 711, the air hole 311 and the interior of the flexible airbag 51 are connected in sequence; therefore, the increased air pressure inside the flexible airbag 51 will be transferred to the two drive housings 72 in sequence through the air hole 311 and the air cavity 711. A return spring 62 is fitted on the slide rod 6; the return spring 62 is located between the piston 61 and the drive housing 72; under normal circumstances, the return spring 62 pushes the piston 61 and the slide rod 6 away from the flexible airbag 51, thereby preventing the compression tube 52 from squeezing the flexible airbag 51; when the piston 61 in the drive housing 72 is subjected to the thrust of air pressure, it will overcome the elastic resistance of the return spring 62 and drive the slide rod 6 to slide along the sliding hole on the bracket 21 towards the flexible airbag 51. Since the ends of the two slide rods 6 away from the piston 61 are connected to the compression tube 52, when the slide rod 6 slides, it will drive the compression tube 52 to move synchronously towards the flexible airbag 51, and uniformly squeeze the periphery of the flexible airbag 51.

[0050] Once the fault repair is completed and the high-voltage terminal 11 is restored to normal, the device can be manually reset to its normal standby state: disconnect the power supply, turn off the alarm and fan 8; de-energize the electromagnet 81, and the iron plate 82 returns to its initial position under its own gravity, and the power switch 83 is turned off; the hot air in the flexible airbag 51 gradually cools down, the air pressure decreases, the reset spring 62 pushes the piston 61 and slide rod 6 to reset, the squeeze tube 52 moves away from the flexible airbag 51, and the flexible airbag 51 returns to flatness; the squeeze spring 34 pushes the squeeze plate 32 and drive rod 31 to reset, and the staff reattaches the new insulating pad 4 to the heating plate 33, waiting for the next fault trigger.

[0051] The working principle of the partial discharge detection device for dry-type transformers in this application is as follows: Under normal conditions, the electric field of the high-voltage terminal 11 is stable with no partial discharge, the detection needle 22 has no induced current, the series circuit with the indicator light 23 is broken, and the indicator light 23 is extinguished; the subsidy unit 3 is in standby state, the compression spring 34 pushes the compression plate 32 and the drive rod 31, and the wrapping unit 5 tightly attaches the EPDM rubber insulating pad 4 to the heating plate 33, sealing the subsidy port 331; the drive unit 7 is reset, and the fan 8, alarm and electromagnet 81 are all in the off state.

[0052] When the high-voltage terminal 11 experiences partial discharge or leakage due to insulation aging or damage, the detection needle 22 draws in the leaked high-voltage stray current, causing the detection needle 22, indicator light 23, and the series-connected heating plate 33 and electromagnet 81 to form a conductive circuit. The indicator light 23 illuminates to indicate the fault, the heating plate 33 starts heating, and the electromagnet 81 is energized and becomes magnetic.

[0053] Heating plate 33 heats insulating pad 4 to 100-110°C to soften it. Compression spring 34 pushes compression plate 32, drive rod 31 and wrapping unit 5 to move, so that the softened insulating pad 4 passes through the patch opening 331 and fits the high voltage terminal 11. At the same time, electromagnet 81 attracts iron plate 82 on bracket 21. Iron plate 82 slides to turn on power switch 83, power is started and power is supplied to fan 8 and alarm. Fan 8 blows air to accelerate the cooling and solidification of insulating pad 4, and alarm sounds a fault warning.

[0054] Simultaneously, the extrusion plate 32 pushes the flexible airbag 51 to be compressed in the middle and protrude on the periphery, initially wrapping the insulating pad 4; the heat from the heating plate 33 increases the air pressure inside the flexible airbag 51, which is transmitted to the drive housing 72 through the air hole 311 and the air cavity 711, pushing the piston 61 and the slide rod 6 to move against the resistance of the return spring 62, driving the extrusion tube 52 to squeeze the flexible airbag 51, so that the insulating pad 4 tightly wraps the terminal; the annular unvulcanized raw rubber on the insulating pad 4 becomes sticky when heated, further enhancing the sealing effect.

[0055] After the insulating rubber pad 4 seals effectively, the discharge phenomenon is suppressed, the detection circuit is disconnected, and the indicator light 23 goes out, indicating that maintenance personnel can safely perform maintenance. After maintenance is completed, the device is manually reset, a new insulating rubber pad 4 is replaced, and all components return to standby status, waiting for the next fault trigger.

[0056] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A partial discharge detection device for a dry-type transformer, characterized in that: The system includes a main body (1) of an intelligent large transformer and multiple sets of discharge detection units (2) disposed on the main body (1). The multiple sets of discharge detection units (2) are respectively located at the high-voltage terminals (11) of the main body (1). Each discharge detection unit (2) includes a bracket (21), a detection needle (22), and an indicator light (23). The bracket (21) is disposed on the main body (1). The indicator light (23) is disposed on the bracket (21). The detection needle (22) is disposed on the bracket (21). One end of the detection needle (22) is directly opposite the high-voltage terminal (11). The other end of the detection needle (22) is connected in series with the indicator light (23) via a wire. A subsidy unit (3) is slidably disposed on the bracket (21). The subsidy unit (3) is used to apply an insulating pad (4) to the high-voltage terminal (11).

2. The partial discharge detection device for a dry-type transformer according to claim 1, characterized in that: The subsidy unit (3) includes a drive rod (31), a pressing plate (32), and a heating plate (33); the drive rod (31) is slidably mounted on the bracket (21); the pressing plate (32) is mounted on one end of the drive rod (31) near the high-voltage terminal (11); the pressing plate (32) is provided with a wrapping unit (5); the insulating pad (4) is mounted on the wrapping unit (5); the heating plate (33) is mounted on the bracket (21); the heating plate (33) is connected in series with the detection needle (22) and the indicator light (23) via wires; the heating plate (33) has a subsidy port (331); the side wall of the insulating pad (4) is attached to the heating plate (33) and located at the subsidy port (331).

3. The partial discharge detection device for a dry-type transformer according to claim 2, characterized in that: The subsidy unit (3) also includes a compression spring (34); the compression spring (34) is sleeved on the drive rod (31) and located between the compression plate (32) and the bracket (21); the compression spring (34) is used to provide force for the compression plate (32) to approach the high voltage terminal (11).

4. The partial discharge detection device for a dry-type transformer according to claim 2, characterized in that: The packaging unit (5) includes a flexible airbag (51); the flexible airbag (51) is disposed on the extrusion plate (32); the insulating pad (4) is disposed on the flexible airbag (51).

5. The partial discharge detection device for a dry-type transformer according to claim 4, characterized in that: The flexible airbag (51) has heat-resistant layers laid on its inner and outer walls, respectively.

6. The partial discharge detection device for a dry-type transformer according to claim 4, characterized in that: The packaging unit (5) also includes a compression tube (52); the compression tube (52) is sleeved on the compression plate (32); one end of the compression tube (52) abuts against the flexible airbag (51).

7. The partial discharge detection device for a dry-type transformer according to claim 6, characterized in that: Two slide rods (6) are connected to one end of the extrusion tube (52) away from the flexible airbag (51); two sliding holes are opened on the bracket (21); the two slide rods (6) are slidably disposed in the two sliding holes respectively; a drive unit (7) is provided on the drive rod (31); the power output end of the drive unit (7) is connected to the two slide rods (6).

8. The partial discharge detection device for a dry-type transformer according to claim 7, characterized in that: The drive unit (7) includes a connector (71) and two drive housings (72); the two drive housings (72) are respectively disposed on the drive rod (31); one end of each of the two slide rods (6) is respectively provided with a piston (61); the two pistons (61) are respectively located inside the two drive housings (72); the connector (71) is disposed on the drive rod (31); an air chamber (711) is provided in the connector (71); the air chamber (711) is connected to the interior of the two drive housings (72); an air hole (311) is provided on the drive rod (31) along its axial direction; the air chamber (711), the air hole (311) and the interior of the flexible airbag (51) are connected in sequence.

9. The partial discharge detection device for a dry-type transformer according to claim 8, characterized in that: A return spring (62) is sleeved on the slide rod (6); the return spring (62) is located between the piston (61) and the drive housing (72); the return spring (62) is used to provide a force for the piston (61) to move away from the flexible airbag (51).

10. The partial discharge detection device for a dry-type transformer according to claim 1, characterized in that: An annular adhesive element (41) is provided on the insulating pad (4).

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