High-temperature-resistant h-class dry-type transformer and manufacturing method thereof

Abstract

The application discloses a high-temperature-resistant H-grade dry-type transformer and a manufacturing method thereof, and relates to the technical field of transformers. The high-temperature-resistant H-grade dry-type transformer comprises a base, an iron core, a winding and a cooling structure, the winding comprises an inner cylinder, an outer cylinder and a supporting block, the cooling structure comprises a heat dissipation channel arranged between the inner cylinder and the outer cylinder, the cooling structure further comprises a gravity ring slidingly connected in the heat dissipation channel, the top of the gravity ring is connected with a lifting ring through a first lifting mechanism, and the top of the winding is provided with a second lifting mechanism for lifting the gravity ring. The high-temperature-resistant H-grade dry-type transformer and the manufacturing method thereof can segmentally and reciprocally cool the inner cylinder and the outer cylinder, the cooling effect is not worse from top to bottom, the cooling efficiency and effect are ensured, targeted and rapid cooling operation can be performed on a high-temperature area, other areas are not affected, and the cooling efficiency and effect are higher and better.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, specifically to a high-temperature resistant H-class dry-type transformer and its manufacturing method. Background Technology

[0002] Dry-type transformers are widely used in high-safety environments such as buildings, subways, data centers, and industrial and mining enterprises due to their oil-free insulation, fire and explosion protection, and ease of maintenance. Among them, H-class dry-type transformers, with their advantages of high temperature resistance, high insulation level, and strong overload capacity, have become the preferred equipment for high-load, high-temperature environments. During operation, the entire coil heats up. The lower part of the coil has the lowest temperature, the middle part has the highest temperature (the hottest spot is here), and the upper part is slightly lower than the middle but higher than the lower part. Furthermore, the voltage regulation function of a dry-type transformer is achieved by switching the tap position of the high-voltage winding. Different tap positions correspond to different effective working turns of the high-voltage winding, which not only changes the overall current density of the winding but also shifts the heating area along the height direction. Combined with the natural temperature distribution characteristic of the winding itself—hotter in the middle and cooler at both ends—significant differences in heating occur at different heights of the winding under different voltage regulation positions, with localized high-temperature points easily appearing in the tap section or the middle area of ​​the winding.

[0003] Publication number CN120878411A discloses a high heat dissipation dry-type transformer. However, existing high-temperature resistant H-class dry-type transformers are cooled by blowing air through a fan during use. Air is blown in from the bottom of the heat dissipation channel and blown out from the top to achieve cooling. The cooling effect is worse the higher up the channel. Furthermore, this method is not convenient for targeted and rapid cooling of high-temperature areas and can easily affect other areas, resulting in low cooling efficiency and poor effect. Summary of the Invention

[0004] The purpose of this invention is to provide a high-temperature resistant H-class dry-type transformer and its manufacturing method, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a high-temperature resistant H-class dry-type transformer, comprising a base, an iron core, windings, and a cooling structure. The windings include an inner cylinder, an outer cylinder, and a support block. The cooling structure includes a heat dissipation channel disposed between the inner and outer cylinders. The cooling structure also includes a gravity ring slidably connected within the heat dissipation channel. The top of the gravity ring is connected to a lifting ring via a first lifting mechanism. The top of the windings is provided with a second lifting mechanism for lifting the gravity ring. A cooling chamber is formed between the gravity ring and the lifting ring. A detection mechanism for detecting temperature is provided within the cooling chamber. The top of the gravity ring is provided with an air inlet mechanism for supplying air into the cooling chamber. The top of the lifting ring is provided with an air outlet mechanism for discharging air from the cavity within the cooling chamber.

[0006] Preferably, the detection mechanism includes a mounting block fixedly connected to the top of the gravity ring, and a temperature sensor is fixedly inserted into the side wall of the mounting block.

[0007] Preferably, the first lifting mechanism includes two symmetrically arranged sleeves fixedly connected to the top of the gravity ring, and each sleeve is inserted with a sleeve rod. The upper end of the sleeve rod is fixed to the top of the lifting ring, and the sleeve rod is connected to the sleeve through a spring. The bottom of the gravity ring is provided with a pulling mechanism for pulling the lifting ring.

[0008] Preferably, the pulling mechanism includes a support plate fixedly connected to the bottom of the gravity ring, and a first motor is fixedly connected to the side wall of the support plate. A first winding roller is fixedly connected to the output end of the first motor, and a first pull rope is fixedly connected to the side wall of the first winding roller. The upper end of the first pull rope is fixed to the bottom of the lifting ring.

[0009] Preferably, the second lifting mechanism includes a support frame fixedly connected to the side wall of the support block, and a second motor is fixedly connected to the side wall of the support frame. A second winding roller is fixedly connected to the output end of the second motor. A second pull rope is fixedly connected to the side wall of the second winding roller, and the lower end of the second pull rope is fixed to the top of the gravity ring.

[0010] Preferably, the air inlet mechanism is formed in the first annular groove on the inner sidewall of the gravity ring, and a rotating cover is rotatably connected in the first annular groove. The top of the rotating cover has multiple air inlets, and multiple stirring plates are fixedly connected to the top of the rotating cover. The bottom of the rotating cover is rotatably connected to a ring, and a connecting block is fixedly connected between the ring and the gravity ring. A fixing pipe is fixedly inserted into the bottom of the ring, and multiple fans are fixedly connected to the sidewall of the base. The air outlet of the fan is connected to the fixing pipe through a first flexible hose, and the rotation of the rotating cover is driven by a driving mechanism.

[0011] Preferably, the driving mechanism includes a fixed box that is fixedly inserted into the side wall of the fixed tube, and a rubber wheel is rotatably connected to the side wall of the fixed box. The rubber wheel abuts against the bottom of the rotating cover, and a power component for driving the rubber wheel to rotate is provided inside the fixed box.

[0012] Preferably, the power assembly includes a rotating fan disposed inside a fixed housing, the rotating fan being rotatably connected to the side wall of the fixed housing via a rotating shaft, and one end of the rotating shaft being fixed to a rubber wheel.

[0013] Preferably, the air outlet mechanism includes a second annular groove formed on the outer wall of the lifting ring, and an annular cover is fixedly connected in the second annular groove. The top of the annular cover is connected to a second flexible hose, and the second flexible hose is connected to the side wall of the support frame through a connecting frame.

[0014] A manufacturing method suitable for high-temperature H-class dry-type transformers includes the following steps:

[0015] S1. Material preparation and pretreatment: Polyimide or polyamide-imide enameled wire with a nominal heat resistance grade of H (180℃) or above is selected as the winding conductor. Mica tape, Nomex® paper or high-density polyester film composite material is selected as interlayer and slot insulation. H-grade epoxy glass cloth board is selected to make insulation support strips, pads, inner cylinders, outer cylinders and other structural components. All insulation materials are tested for matching thermal expansion coefficients. The iron core is processed with low-loss silicon steel sheets and the clamps are treated with anti-corrosion. The gravity ring, lifting ring and various transmission components of the cooling structure are treated with high temperature resistance and rust prevention.

[0016] S2. Transformer body assembly: Fix the iron core to the base, wind the high and low voltage windings and fit them on the iron core column, assemble the inner cylinder, outer cylinder and support block to form the winding body with heat dissipation channel, slide the gravity ring in the heat dissipation channel, connect the gravity ring and the lifting ring through the first lifting mechanism, assemble the second lifting mechanism on the top of the winding, and install the detection mechanism, air inlet mechanism and air outlet mechanism in sequence to complete the overall assembly of the transformer body. During assembly, set the elastic insulation buffer structure in the area of ​​concentrated thermal stress, and retain the fitting gap in the insulation shrinkage reserved part.

[0017] S3. Vacuum Pressure Impregnation (VPI): After pre-drying and dehumidifying the assembled body, place it into the VPI tank, evacuate to a residual pressure of <10Pa and maintain for 1 hour, inject H-grade solvent-free epoxy or silicone resin insulating varnish, and maintain pressure at 0.6MPa for 3 hours to allow the insulating varnish to fully penetrate into the windings, insulating components and various structural gaps.

[0018] S4. Staged Precision Curing: The impregnated container body is sent into a curing oven to perform a step-by-step curing process. Stage 1: The temperature is increased from room temperature to 80-100℃ at a rate of ≤5℃ / h and held for 2-4 hours to remove residual low-molecular-weight substances in the paint. Stage 2: The temperature is increased to 120-130℃ at a rate of ≤5℃ / h and held for 4-6 hours to complete the initial cross-linking of the resin. Stage 3: The temperature is increased to 150℃±2℃ at a rate of ≤5℃ / h and held for 8-10 hours to achieve deep and complete three-dimensional cross-linking of the resin. After curing, the container body is cooled to below 80℃ in the oven before being removed from the oven.

[0019] S5. Commissioning and Testing: After the transformer is taken out of the furnace, the cooling structure is debugged to verify the lifting and lowering action of the gravity ring and the lifting ring, the airflow delivery effect of the air inlet and outlet mechanisms, the temperature sensing accuracy of the testing mechanism and the coordination of each mechanism. Then, a full set of type tests are carried out on the transformer, focusing on testing the winding insulation resistance, dielectric loss factor and partial discharge under the 180℃ thermal stability state to ensure that all performance indicators meet the high temperature resistance requirements of H-class dry-type transformers.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] (1) The high-temperature H-class dry-type transformer and its manufacturing method, by setting a second lifting mechanism, an air inlet mechanism and an air outlet mechanism, etc., when cooling, the fan is started so that the external air can enter the rotating cover through the first hose and the fixed pipe. Then, it enters the cooling chamber between the gravity ring and the lifting ring through the air inlet. At this time, the inner cylinder and the outer cylinder can be cooled. The cooled air enters the annular cover and then is discharged from the top of the winding through the second hose. At the same time, the gravity ring and the lifting ring can be driven to rise and fall along the heat dissipation channel by the second lifting mechanism. The second motor is started to drive the second winding roller to rotate, which can wind the second pull rope, thereby pulling the gravity ring to move upward. At the same time, the lifting ring is driven to move upward by the first lifting mechanism. When the second motor reverses, the gravity ring and the lifting ring can move downward and reset under the action of gravity. This process is repeated to cool the inner cylinder and the outer cylinder in segments. The cooled air will not come into contact with the inner cylinder and the outer cylinder in other positions, which can avoid interference and ensure the efficiency and effect of cooling.

[0022] (2) The high-temperature H-class dry-type transformer and its manufacturing method, by setting a drive mechanism, etc., when cooling, when air enters the fixed tube, it can enter the fixed box and impact the surface of the rotating fan, causing the rotating fan to rotate. When the rotating fan rotates, it can drive the rubber wheel to rotate through the rotating shaft, thereby driving the rotating cover to rotate, and then driving the stirring plate to rotate. When air enters the rotating cover, it can be stirred by the stirring plate to make it more uniform. Then, when it enters the cooling chamber through the air inlet, with the rotation of the rotating cover, the air entering the cooling chamber can be more uniform, thereby making the cooling effect of the inner cylinder and the outer cylinder better.

[0023] (3) The high-temperature H-class dry-type transformer and its manufacturing method, by setting up a detection mechanism, can monitor the temperature of each height of the winding by a temperature sensor when the gravity ring and the lifting ring move up and down in the heat dissipation channel. When the temperature in a certain range is detected to be too high, the first motor can be started to reverse. At this time, the first pull rope is gradually loosened, and the lifting ring can move upward under the action of the spring, so that the cooling chamber completely covers the height range and performs cooling operation. It can perform targeted and rapid cooling operation on the high-temperature area, and can avoid affecting other areas, making the cooling efficiency higher and the effect better. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2This is a partial cross-sectional view of the outer cylinder in this invention;

[0026] Figure 3 This is a partial cross-sectional view of the outer cylinder from another perspective in this invention;

[0027] Figure 4 This is a schematic diagram of the structure of the first lifting mechanism in this invention;

[0028] Figure 5 This is a schematic diagram of the gravity ring and lifting ring in this invention;

[0029] Figure 6 This is a schematic diagram of the structure of the second lifting mechanism in this invention;

[0030] Figure 7 This is a schematic diagram of the detection mechanism in this invention;

[0031] Figure 8 This is a partial cross-sectional view of the fixed box in this invention.

[0032] In the diagram: 101, base; 102, iron core; 103, inner cylinder; 104, outer cylinder; 105, support block; 106, heat dissipation channel; 201, sleeve; 202, sleeve rod; 301, support plate; 302, first motor; 303, first winding roller; 304, first pull rope; 401, support frame; 402, second motor; 403, second winding roller; 404, second pull rope; 501, mounting block; 502, temperature sensor; 60 1. First annular groove; 602. Rotating cover; 603. Stirring plate; 604. Air inlet; 605. Fixed pipe; 606. Fan; 607. First flexible hose; 608. Connecting block; 609. Ring; 701. Second annular groove; 702. Annular cover; 703. Second flexible hose; 704. Connecting frame; 801. Rubber wheel; 802. Fixed box; 901. Rotating shaft; 902. Rotating fan; 1001. Gravity ring; 1002. Lifting ring. Detailed Implementation

[0033] 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.

[0034] Please see Figures 1-8This invention provides a high-temperature resistant H-class dry-type transformer, including a base 101, an iron core 102, windings, and a cooling structure. The windings include an inner cylinder 103, an outer cylinder 104, and a support block 105. The cooling structure includes a heat dissipation channel 106 disposed between the inner cylinder 103 and the outer cylinder 104. These are well-known technologies in this field and will not be described in detail here. The cooling structure also includes a gravity ring 1001 slidably connected within the heat dissipation channel 106. The top of the gravity ring 1001 is connected to a lifting ring 1002 via a first lifting mechanism. A second lifting mechanism for lifting the gravity ring 1001 is provided at the top of the windings. A cooling chamber is formed between the inner cylinder 103 and the lifting ring 1002, and a detection mechanism for detecting temperature is provided in the cooling chamber. An air inlet mechanism for supplying air into the cooling chamber is provided at the top of the gravity ring 1001, and an air outlet mechanism for discharging air from the cavity in the cooling chamber is provided at the top of the lifting ring 1002. This allows for segmented reciprocating cooling of the inner cylinder 103 and the outer cylinder 104, preventing the cooling effect from decreasing as you go higher, ensuring cooling efficiency and effectiveness. Furthermore, it enables targeted and rapid cooling of high-temperature areas and avoids affecting other areas, resulting in higher cooling efficiency and better effect.

[0035] Please see Figure 5 and Figure 7 The detection mechanism includes a mounting block 501 fixedly connected to the top of the gravity ring 1001, and a temperature sensor 502 is fixedly inserted into the side wall of the mounting block 501. When the gravity ring 1001 and the lifting ring 1002 move up and down in the heat dissipation channel 106, the temperature of the winding at each height can be inspected by the temperature sensor 502.

[0036] Please see Figure 4 and Figure 8 The first lifting mechanism includes two symmetrically arranged sleeves 201 fixedly connected to the top of the gravity ring 1001, and each sleeve 201 is inserted with a sleeve rod 202. The upper end of the sleeve rod 202 is fixed to the top of the lifting ring 1002, and the sleeve rod 202 is connected to the sleeve 201 by a spring. The bottom of the gravity ring 1001 is provided with a pulling mechanism for pulling the lifting ring 1002. By pulling the lifting ring 1002 through the pulling mechanism, the lifting ring 1002 moves closer to the gravity ring 1001. At the same time, the sleeve rod 202 slides into the sleeve 201, the spring is compressed, and the height of the cooling chamber can be adjusted.

[0037] Please see Figure 4 and Figure 8The pulling mechanism includes a support plate 301 fixedly connected to the bottom of the gravity ring 1001, and a first motor 302 fixedly connected to the side wall of the support plate 301. A first winding roller 303 is fixedly connected to the output end of the first motor 302, and a first pull rope 304 is fixedly connected to the side wall of the first winding roller 303. The upper end of the first pull rope 304 is fixed to the bottom of the lifting ring 1002. When the first motor 302 is started, the rotation of the first motor 302 drives the first winding roller 303 to rotate, thereby winding the first pull rope 304 and pulling the lifting ring 1002 downward.

[0038] Please see Figure 3 , Figure 5 , Figure 6 and Figure 7 The second lifting mechanism includes a support frame 401 fixedly connected to the side wall of the support block 105, and a second motor 402 fixedly connected to the side wall of the support frame 401. A second winding roller 403 is fixedly connected to the output end of the second motor 402, and a second pull rope 404 is fixedly connected to the side wall of the second winding roller 403. The lower end of the second pull rope 404 is fixed to the top of the gravity ring 1001. When the second motor 402 is started, the second winding roller 403 is driven to rotate, which can wind up the second pull rope 404, thereby pulling the gravity ring 1001 to move upward. At the same time, the lifting ring 1002 is driven to move upward through the first lifting mechanism. When the second motor 402 reverses, the gravity ring 1001 and the lifting ring 1002 can move downward and reset under the action of gravity. This process is repeated to lift the gravity ring 1001 and the lifting ring 1002.

[0039] Please see Figure 7 and Figure 8 The air intake mechanism is located in the first annular groove 601 on the inner sidewall of the gravity ring 1001, and a rotating cover 602 is rotatably connected within the first annular groove 601. Multiple air intake holes 604 are provided on the top of the rotating cover 602, and multiple stirring plates 603 are fixedly connected to the top of the rotating cover 602. A circular ring 609 is rotatably connected to the bottom of the rotating cover 602, and a connecting block 608 is fixedly connected between the circular ring 609 and the gravity ring 1001. A fixing tube 605 is fixedly inserted into the bottom of the circular ring 609, and the side of the base 101... Multiple fans 606 are fixedly connected to the wall. The air outlet of the fan 606 is connected to the fixed pipe 605 through the first hose 607. The rotation of the rotating cover 602 is driven by the drive mechanism. When cooling, the fan 606 is started so that the outside air can enter the rotating cover 602 through the first hose 607 and the fixed pipe 605. Then, it enters the cooling chamber between the gravity ring 1001 and the lifting ring 1002 through the air inlet 604. At this time, the inner cylinder 103 and the outer cylinder 104 can be cooled.

[0040] Please see Figure 8The driving mechanism includes a fixed box 802 fixedly inserted into the side wall of the fixed tube 605, and a rubber wheel 801 is rotatably connected to the side wall of the fixed box 802. The rubber wheel 801 abuts against the bottom of the rotating cover 602, and a power component for driving the rubber wheel 801 to rotate is provided inside the fixed box 802. When cooling, when air enters the fixed tube 605, it can enter the fixed box 802 and drive the rubber wheel 801 to rotate through the power component, thereby driving the rotating cover 602 to rotate, and then driving the stirring plate 603 to rotate. When air enters the rotating cover 602, it can be stirred by the stirring plate 603 to make it more uniform. Then, when it enters the cooling chamber through the air inlet 604, the rotation of the rotating cover 602 makes the air entering the cooling chamber more uniform, thereby making the cooling effect of the inner cylinder 103 and the outer cylinder 104 better.

[0041] Please see Figure 8 The power assembly includes a rotating fan 902 installed inside a fixed housing 802. The rotating fan 902 is rotatably connected to the side wall of the fixed housing 802 via a rotating shaft 901, and one end of the rotating shaft 901 is fixed to a rubber wheel 801. When air enters the fixed pipe 605, it can enter the fixed housing 802 and impact the surface of the rotating fan 902, causing the rotating fan 902 to rotate. When the rotating fan 902 rotates, it can drive the rubber wheel 801 to rotate via the rotating shaft 901.

[0042] Please see Figure 3 , Figure 6 and Figure 7 The air outlet mechanism includes a second annular groove 701 opened on the outer wall of the lifting ring 1002, and an annular cover 702 is fixedly connected in the second annular groove 701. The top of the annular cover 702 is connected to a second flexible hose 703, and the second flexible hose 703 is connected to the side wall of the support frame 401 through a connecting frame 704. The cooled air enters the annular cover 702, and then is discharged from the top of the winding through the second flexible hose 703. The cooled air will not come into contact with the inner cylinder 103 and the outer cylinder 104 in other positions, thus avoiding any impact.

[0043] A manufacturing method suitable for high-temperature H-class dry-type transformers includes the following steps:

[0044] S1. Material preparation and pretreatment: Polyimide or polyamide-imide enameled wire with a nominal heat resistance grade of H (180℃) or above is selected as the winding conductor. Mica tape, Nomex® paper or high-density polyester film composite material is selected as interlayer and slot insulation. H-grade epoxy glass cloth board is selected to make insulation support strips, pads, inner cylinders, outer cylinders and other structural components. All insulation materials are tested for matching thermal expansion coefficients. The iron core is processed with low-loss silicon steel sheets and the clamps are treated with anti-corrosion. The gravity ring, lifting ring and various transmission components of the cooling structure are treated with high temperature resistance and rust prevention.

[0045] S2. Transformer body assembly: Fix the iron core to the base, wind the high and low voltage windings and fit them on the iron core column, assemble the inner cylinder, outer cylinder and support block to form the winding body with heat dissipation channel, slide the gravity ring in the heat dissipation channel, connect the gravity ring and the lifting ring through the first lifting mechanism, assemble the second lifting mechanism on the top of the winding, and install the detection mechanism, air inlet mechanism and air outlet mechanism in sequence to complete the overall assembly of the transformer body. During assembly, set the elastic insulation buffer structure in the area of ​​concentrated thermal stress, and retain the fitting gap in the insulation shrinkage reserved part.

[0046] S3. Vacuum Pressure Impregnation (VPI): After pre-drying and dehumidifying the assembled body, place it into the VPI tank, evacuate to a residual pressure of <10Pa and maintain for 1 hour, inject H-grade solvent-free epoxy or silicone resin insulating varnish, and maintain pressure at 0.6MPa for 3 hours to allow the insulating varnish to fully penetrate into the windings, insulating components and various structural gaps.

[0047] S4. Staged Precision Curing: The impregnated container body is sent into a curing oven to perform a step-by-step curing process. Stage 1: The temperature is increased from room temperature to 80-100℃ at a rate of ≤5℃ / h and held for 2-4 hours to remove residual low-molecular-weight substances in the paint. Stage 2: The temperature is increased to 120-130℃ at a rate of ≤5℃ / h and held for 4-6 hours to complete the initial cross-linking of the resin. Stage 3: The temperature is increased to 150℃±2℃ at a rate of ≤5℃ / h and held for 8-10 hours to achieve deep and complete three-dimensional cross-linking of the resin. After curing, the container body is cooled to below 80℃ in the oven before being removed from the oven.

[0048] S5. Commissioning and Testing: After the transformer is taken out of the furnace, the cooling structure is debugged to verify the lifting and lowering action of the gravity ring and the lifting ring, the airflow delivery effect of the air inlet and outlet mechanisms, the temperature sensing accuracy of the testing mechanism and the coordination of each mechanism. Then, a full set of type tests are carried out on the transformer, focusing on testing the winding insulation resistance, dielectric loss factor and partial discharge under the 180℃ thermal stability state to ensure that all performance indicators meet the high temperature resistance requirements of H-class dry-type transformers.

[0049] Working principle: During use, when cooling, the fan 606 is started, allowing external air to enter the rotating cover 602 through the first hose 607 and the fixed pipe 605. Then, it enters the cooling chamber between the gravity ring 1001 and the lifting ring 1002 through the air inlet 604. At this time, the inner cylinder 103 and the outer cylinder 104 can be cooled. The cooled air enters the annular cover 702 and then is discharged from the top of the winding through the second hose 703.

[0050] Meanwhile, the gravity ring 1001 and the lifting ring 1002 can be driven to rise and fall along the heat dissipation channel 106 by the second lifting mechanism. The second motor 402 is started, which drives the second winding roller 403 to rotate, which can wind up the second pull rope 404, thereby pulling the gravity ring 1001 to move upward. At the same time, the lifting ring 1002 is driven to move upward by the first lifting mechanism. When the second motor 402 reverses, the gravity ring 1001 and the lifting ring 1002 can move downward and reset under the action of gravity. This process is repeated to cool the inner cylinder 103 and the outer cylinder 104 in segments. The cooled air will not come into contact with the inner cylinder 103 and the outer cylinder 104 in other positions, which can avoid interference and ensure the efficiency and effect of cooling.

[0051] When air enters the fixed pipe 605, it enters the fixed box 802 and impacts the surface of the rotating fan 902, causing the fan 902 to rotate. When the fan 902 rotates, it drives the rubber wheel 801 to rotate via the rotating shaft 901, thereby driving the rotating cover 602 to rotate, which in turn drives the stirring plate 603 to rotate. When air enters the rotating cover 602, it is agitated by the stirring plate 603, making it more uniform. Then, when it enters the cooling chamber through the air inlet 604, the rotation of the rotating cover 602 makes the air entering the cooling chamber more uniform, thus improving the cooling effect on the inner cylinder 103 and the outer cylinder 104.

[0052] When the gravity ring 1001 and the lifting ring 1002 move up and down within the heat dissipation channel 106, the temperature sensor 502 can monitor the temperature at various heights of the winding. When an excessively high temperature is detected in a certain range, the first motor 302 can be started to reverse. At this time, the first pull rope 304 is gradually loosened, and the lifting ring 1002 can move upward under the action of the spring, so that the cooling chamber completely covers the height range and performs cooling operations. This allows for targeted and rapid cooling of high-temperature areas and avoids affecting other areas, resulting in higher cooling efficiency and better effect.

[0053] All standard parts used in this invention can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here. The contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0054] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A high-temperature resistant H-class dry-type transformer, comprising a base (101), an iron core (102), windings, and a cooling structure, wherein the windings comprise an inner cylinder (103), an outer cylinder (104), and a support block (105), and the cooling structure comprises a heat dissipation channel (106) disposed between the inner cylinder (103) and the outer cylinder (104), characterized in that: The cooling structure also includes a gravity ring (1001) slidably connected in the heat dissipation channel (106), and the top of the gravity ring (1001) is connected to a lifting ring (1002) through a first lifting mechanism. The top of the winding is provided with a second lifting mechanism for lifting the gravity ring (1001). A cooling chamber is formed between the gravity ring (1001) and the lifting ring (1002), and a detection mechanism for detecting temperature is provided in the cooling chamber. The top of the gravity ring (1001) is provided with an air inlet mechanism for supplying air into the cooling chamber, and the top of the lifting ring (1002) is provided with an air outlet mechanism for discharging air from the cavity in the cooling chamber.

2. The high-temperature resistant H-class dry-type transformer according to claim 1, characterized in that: The detection mechanism includes a mounting block (501) fixedly connected to the top of the gravity ring (1001), and a temperature sensor (502) is fixedly inserted into the side wall of the mounting block (501).

3. The high-temperature resistant H-class dry-type transformer according to claim 1, characterized in that: The first lifting mechanism includes two symmetrically arranged sleeves (201) fixedly connected to the top of the gravity ring (1001), and each sleeve (201) is inserted with a sleeve rod (202). The upper end of the sleeve rod (202) is fixed to the top of the lifting ring (1002), and the sleeve rod (202) is connected to the sleeve (201) by a spring. The bottom of the gravity ring (1001) is provided with a pulling mechanism for pulling the lifting ring (1002).

4. A high-temperature resistant H-class dry-type transformer according to claim 3, characterized in that: The pulling mechanism includes a support plate (301) fixedly connected to the bottom of the gravity ring (1001), and a first motor (302) is fixedly connected to the side wall of the support plate (301). The output end of the first motor (302) is fixedly connected to a first winding roller (303), and a first pull rope (304) is fixedly connected to the side wall of the first winding roller (303). The upper end of the first pull rope (304) is fixed to the bottom of the lifting ring (1002).

5. A high-temperature resistant H-class dry-type transformer according to claim 1, characterized in that: The second lifting mechanism includes a support frame (401) fixedly connected to the side wall of the support block (105), and a second motor (402) fixedly connected to the side wall of the support frame (401). The output end of the second motor (402) is fixedly connected to a second winding roller (403), and a second pull rope (404) is fixedly connected to the side wall of the second winding roller (403). The lower end of the second pull rope (404) is fixed to the top of the gravity ring (1001).

6. A high-temperature resistant H-class dry-type transformer according to claim 1, characterized in that: The air intake mechanism is opened in the first annular groove (601) on the inner side wall of the gravity ring (1001), and a rotating cover (602) is rotatably connected in the first annular groove (601). The top of the rotating cover (602) is provided with multiple air inlets (604), and multiple stirring plates (603) are fixedly connected to the top of the rotating cover (602). The bottom of the rotating cover (602) is rotatably connected with a ring (609), and a connecting block (608) is fixedly connected between the ring (609) and the gravity ring (1001). A fixing pipe (605) is fixedly inserted into the bottom of the ring (609), and multiple fans (606) are fixedly connected to the side wall of the base (101). The air outlet of the fan (606) is connected to the fixing pipe (605) through a first flexible hose (607), and the rotation of the rotating cover (602) is driven by a driving mechanism.

7. A high-temperature resistant H-class dry-type transformer according to claim 6, characterized in that: The driving mechanism includes a fixed box (802) fixedly inserted into the side wall of the fixed tube (605), and a rubber wheel (801) is rotatably connected to the side wall of the fixed box (802). The rubber wheel (801) abuts against the bottom of the rotating cover (602), and a power component for driving the rubber wheel (801) to rotate is provided inside the fixed box (802).

8. A high-temperature resistant H-class dry-type transformer according to claim 7, characterized in that: The power assembly includes a rotating fan (902) disposed in a fixed box (802). The rotating fan (902) is rotatably connected to the side wall of the fixed box (802) via a rotating shaft (901), and one end of the rotating shaft (901) is fixed to a rubber wheel (801).

9. A high-temperature resistant H-class dry-type transformer according to claim 1, characterized in that: The air outlet mechanism includes a second annular groove (701) opened on the outer wall of the lifting ring (1002), and an annular cover (702) is fixedly connected in the second annular groove (701). The top of the annular cover (702) is connected to a second flexible hose (703), and the second flexible hose (703) is connected to the side wall of the support frame (401) through a connecting frame (704).

10. A manufacturing method applicable to the high-temperature resistant H-class dry-type transformer according to any one of claims 1-9, characterized in that: Includes the following steps: S1. Material preparation and pretreatment: Polyimide or polyamide-imide enameled wire with a nominal heat resistance grade of H (180℃) or above is selected as the winding conductor. Mica tape, Nomex® paper or high-density polyester film composite material is selected as interlayer and slot insulation. H-grade epoxy glass cloth board is selected to make insulation support strips, pads, inner cylinder and outer cylinder structural components. All insulation materials are tested for matching thermal expansion coefficient. The iron core is processed with low-loss silicon steel sheets and the clamps are treated with anti-corrosion. The gravity ring, lifting ring and various transmission components of the cooling structure are treated with high temperature resistance and rust prevention. S2. Transformer body assembly: Fix the iron core to the base, wind the high and low voltage windings and fit them on the iron core column, assemble the inner cylinder, outer cylinder and support block to form the winding body with heat dissipation channel, slide the gravity ring in the heat dissipation channel, connect the gravity ring and the lifting ring through the first lifting mechanism, assemble the second lifting mechanism on the top of the winding, and install the detection mechanism, air inlet mechanism and air outlet mechanism in sequence to complete the overall assembly of the transformer body. During assembly, set the elastic insulation buffer structure in the area of ​​concentrated thermal stress, and retain the fitting gap in the insulation shrinkage reserved part. S3. Vacuum Pressure Impregnation (VPI): After pre-drying and dehumidifying the assembled body, place it into the VPI tank, evacuate to a residual pressure of <10Pa and maintain for 1 hour, inject H-grade solvent-free epoxy or silicone resin insulating varnish, and maintain pressure at 0.6MPa for 3 hours to allow the insulating varnish to fully penetrate into the windings, insulating components and various structural gaps. S4. Staged Precision Curing: The impregnated container body is sent into a curing oven to perform a step-by-step curing process. Stage 1: The temperature is increased from room temperature to 80-100℃ at a rate of ≤5℃ / h and held for 2-4 hours to remove residual low-molecular-weight substances in the paint. Stage 2: The temperature is increased to 120-130℃ at a rate of ≤5℃ / h and held for 4-6 hours to complete the initial cross-linking of the resin. Stage 3: The temperature is increased to 150℃±2℃ at a rate of ≤5℃ / h and held for 8-10 hours to achieve deep and complete three-dimensional cross-linking of the resin. After curing, the container body is cooled to below 80℃ in the oven before being removed from the oven. S5. Commissioning and Testing: After the transformer is taken out of the furnace, the cooling structure is debugged to verify the lifting and lowering action of the gravity ring and the lifting ring, the airflow delivery effect of the air inlet and outlet mechanisms, the temperature sensing accuracy of the testing mechanism and the coordination of each mechanism. Then, a full set of type tests are carried out on the transformer, focusing on testing the winding insulation resistance, dielectric loss factor and partial discharge under the 180℃ thermal stability state to ensure that all performance indicators meet the high temperature resistance requirements of H-class dry-type transformers.

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