Transformer withstand voltage test device and test method

Abstract

The invention belongs to the technical field of transformer testing, and particularly relates to a transformer withstand voltage testing device and method, the transformer withstand voltage testing device comprises a base table, a fixing frame, an isolation box and a fixing frame, a fire extinguisher is installed in the fixing frame, a voltage regulator is installed in the isolation box, and a lifting table is installed on the base table; the cylinder is installed on the fixing frame, and the induction table is installed at the output end of the cylinder and connected with the testing table through the first electromagnetic chuck. The test bench is provided with a test probe, and the induction bench is provided with a sensor group. If the transformer catches fire in the pressure maintaining process, the sensor group controls the fire extinguisher to extinguish the fire of the transformer, and if the fire behavior is small and controllable; the electromagnetic chuck II is powered off, so that the test board is connected with the inclined plane block II; the cylinder controls the induction bench and the test bench to move up and down to drive the voltage regulating gear to rotate, thereby reducing the voltage of the detection circuit, and avoiding the direct power failure of the detection circuit, causing the instantaneous sudden change of the output voltage of the transformer, and further causing extra damage to the tested transformer.

Description

Technical Field

[0001] The present invention belongs to the technical field of transformer testing, and particularly relates to a withstand voltage testing device and a testing method for a transformer. Background Art

[0002] A transformer withstand voltage testing device is an important equipment for detecting the insulation performance of a transformer, mainly used to evaluate the insulation strength and stability of the transformer under high voltage. When a transformer leaves the factory, it has not been tested under harsh environments for a long time, nor has it undergone long-term tests with a power supply of rated voltage and frequency. Therefore, there may be potential insulation faults in the transformer, and these faults do not differ much from those of a transformer with good insulation performance in terms of no-load current and no-load power consumption, so it is difficult to detect. The withstand voltage testing device applies a voltage more than twice the rated voltage to the transformer, establishing a higher and more concentrated electric field strength at the longitudinal insulation defects, so that the voltages between turns, layers, and sections of the winding reach and exceed the breakdown voltage at the dielectric defects, thereby reliably detecting the longitudinal insulation performance of the transformer.

[0003] When testing a transformer, the transformer needs to be connected to the test circuit, and then the voltage regulator is adjusted to increase the voltage; when the test voltage reaches the set value, the voltage is kept stable and the timing starts until the withstand voltage test ends.

[0004] If the transformer catches fire or smokes during the voltage holding process, the transformer needs to be powered off in time. For example, in the patent with publication number CN118818378A, when the transformer catches fire during the voltage holding process, the test equipment is quickly separated from the transformer through a rebound control component. However, due to the high voltage of the test circuit, directly powering off may cause an instantaneous mutation of the output voltage of the test transformer, generating a high switching overvoltage and causing additional damage to the transformer under test. Summary of the Invention

[0005] The purpose of the present invention is to provide a withstand voltage testing device and a testing method for a transformer in view of the deficiencies of the prior art, so as to solve the technical problems in the prior art.

[0006] The object of the present invention can be achieved by the following technical solutions: A transformer withstand voltage testing device, which includes a base platform, a fixing frame is installed on the base platform, an isolation box and a fixing frame are installed inside the fixing frame, the fixing frame is located at the bottom of the isolation box, a fire extinguisher is installed inside the fixing frame, a voltage regulator is installed inside the isolation box, and a lifting platform is installed on the base platform; A cylinder is installed on the fixing frame, an induction table is installed at the output end of the cylinder, the induction table is connected to the test table through an electromagnetic chuck I, the test table is located on top of the induction table, and the test table is connected to the fixing frame through a spring II; A test probe is installed on the test table, and a sensor group is installed on the induction table; A side plate is installed on the isolation box, a voltage regulating gear is installed on the voltage regulator, a baffle is installed on the side plate, longitudinal sliding grooves are opened on the isolation box and the baffle, a rack is slidably installed in the longitudinal sliding groove on the isolation box, and an inclined block I is slidably installed in the longitudinal sliding groove on the baffle, the rack and the inclined block I are in contact through an inclined surface, and the rack and the voltage regulating gear are detachably connected, and an inclined block II is installed on the inclined block I; The test table abuts against the inclined block II, and the test table can also be connected to the inclined block II; A push-button switch is installed on the top of the test table.

[0007] As a further optimization or improvement of this solution, a side plate is installed on the isolation box, a side sliding groove is opened on the side plate, and the test table is slidably matched with the side sliding groove.

[0008] As a further optimization or improvement of this solution, a guide bar is installed on the inclined surface of the rack, a guide groove is opened on the inclined surface of the inclined block I, and the guide groove is slidably connected to the guide bar.

[0009] As a further optimization or improvement of this solution, a pressing plate is slidably installed horizontally in the longitudinal sliding groove, and the pressing plate is connected to the inner wall of the isolation box through a spring.

[0010] As a further optimization or improvement of this solution, a horizontal sliding groove is opened on the side wall of the test table, a plug block is slidably installed in the horizontal sliding groove, the plug block is connected to the test table through a spring I, a metal plate is installed on the plug block, and an electromagnetic chuck II is installed at the bottom of the horizontal sliding groove, and the electromagnetic chuck II adsorbs the metal plate; A clamping groove is opened on the inclined block II, and the test table is connected to the inclined block II by inserting the plug block into the clamping groove.

[0011] As a further optimization or improvement of this solution, the sensor group includes a smoke sensor and a flame sensor.

[0012] A transformer withstand voltage testing method, which is applied to the transformer withstand voltage testing device as described above, and the method includes the following steps: Step S1: Fix the transformer on the lifting platform, drive the induction table and the test table to move down synchronously through the cylinder, connect the test probe to the transformer, and boost the voltage by adjusting the voltage regulator; Step S2: When the test voltage reaches the set value, keep the voltage stable and start timing until the withstand voltage test ends; Step S3: During the downward movement of the induction table and the test table, through the cooperation of the inclined plane on the side wall of the test table and the second inclined plane block, the test table pushes the second inclined plane block and the first inclined plane block to move outward, making the first inclined plane block move closer to the rack direction. Through the cooperation of the inclined plane on the rack and the first inclined plane block, the first inclined plane block pushes the tooth surface of the rack to move closer to the pressure regulating gear direction and engage with the pressure regulating gear; Step S4: If the transformer catches fire during the pressure holding process, the flame sensor in the sensor group detects the flame and controls the activation of the fire extinguisher, and the fire extinguisher extinguishes the fire on the transformer; Step S5: The sensor group detects the fire situation. If the fire is small and controllable, the second electromagnetic chuck is powered off. At this time, the insertion block is inserted into the card slot under the elastic return of the first spring, connecting the test table with the second inclined plane block. The induction table and the test table are controlled by the cylinder to move upward, and at the same time, the lifting table lifts the transformer, so that the transformer moves upward at the same speed as the induction table and the test table; Step S6: During the upward movement of the test table, the test table drives the rack to move synchronously through the first inclined plane block. Under the action of the engagement between the rack and the pressure regulating gear, the upward movement of the test table drives the pressure regulating gear to rotate, thereby reducing the voltage of the detection circuit. Until the push-button switch on the top of the test table contacts the fixed frame, the detection circuit is powered off; Step S7: Control the transformer to reset through the lifting table, so that the transformer is disconnected from the test probe.

[0013] Advantages of the present invention: (1) If the transformer catches fire during the pressure holding process, the sensor group controls the fire extinguisher to extinguish the fire on the transformer. During this process, if the fire is small and controllable; by powering off the second electromagnetic chuck, the test table is connected to the second inclined plane block.

[0014] Specifically, the induction table and the test table are controlled by the cylinder to move upward, and at the same time, the lifting table lifts the transformer, so that the transformer moves upward at the same speed as the induction table and the test table; during the upward movement of the test table, the test table drives the rack to move synchronously through the first inclined plane block, making the rack drive the pressure regulating gear to rotate, thereby reducing the voltage of the detection circuit. Until the push-button switch on the top of the test table contacts the fixed frame, the detection circuit is powered off, avoiding the direct power-off of the detection circuit, resulting in an instantaneous mutation of the output voltage of the transformer, and further causing additional damage to the transformer under test. During the voltage reduction and power-off process of the present invention, the lifting table lifts the transformer, isolating the transformer from the ground, which can reduce the risk of electric shock caused by ground moisture.

[0015] (2) If the transformer catches fire during the pressure-holding process and the fire is intense, the present invention energizes the second electromagnetic chuck, causing the insertion block to disengage from the card slot and slide into the lateral chute, disconnecting the test bench from the second inclined block; the first electromagnetic chuck is de-energized, disconnecting the induction table from the test bench. The test bench quickly moves upward under the action of the second spring. When the push-button switch on the top of the test bench contacts the fixed frame, the detection circuit is de-energized. When the fire is intense, the present invention skips the circuit voltage reduction process and directly de-energizes the detection circuit to avoid high voltage assisting combustion and prevent the fire from further spreading due to electrification. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below in conjunction with the drawings.

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0018] Figure 2 It is a front view of the overall structure of the present invention.

[0019] Figure 3 It is a schematic diagram of the installation positions of the sensor group and the test probe.

[0020] Figure 4 It is a cross-sectional view of the overall structure of the present invention.

[0021] Figure 5 For Figure 4 Enlarged view of the structure of part A of

[0022] Figure 6 It is a schematic diagram of the installation position of the baffle.

[0023] Figure 7 It is a schematic diagram of the installation positions of the rack and the first inclined block.

[0024] Figure 8 It is a schematic diagram of the connection structure between the rack and the first inclined block.

[0025] Figure 9 It is a schematic diagram of the installation position structure of the pressing plate.

[0026] Figure 10 For Figure 4 Enlarged view of the structure of part B of

[0027] Figure 11 It is a schematic diagram of the sliding connection between the test bench and the side chute.

[0028] The labels in the figure are: 1, base; 2, fixing frame; 3, cylinder; 4, isolation box; 5, fixing frame; 6, lifting platform; 7, fire extinguisher; 8, side plate; 9, second spring; 10, voltage regulator; 11, voltage regulating gear; 12, side chute; 13, longitudinal chute; 14, rack; 15, first inclined block; 16, baffle; 17, second inclined block; 18, card slot; 19, guide groove; 20, guide bar; 21, pressing plate; 22, induction platform; 23, test platform; 24, sensor group; 25, first electromagnetic chuck; 26, first spring; 27, test probe; 28, second electromagnetic chuck; 29, metal plate; 30, push-button switch; 31, transverse chute; 32, insertion block. Specific embodiments

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] See Figures 1-11 , a withstand voltage test device for a transformer, which includes a base 1, a fixing frame 2 is installed on the base 1, an isolation box 4 and a fixing frame 5 are installed in the fixing frame 2, the fixing frame 5 is located at the bottom of the isolation box 4, a fire extinguisher 7 is installed in the fixing frame 5, a voltage regulator 10 is installed in the isolation box 4, and a lifting platform 6 is installed on the base 1; a cylinder 3 is installed on the fixing frame 2, an induction platform 22 is installed at the output end of the cylinder 3, the induction platform 22 is connected to a test platform 23 through a first electromagnetic chuck 25, the test platform 23 is located on top of the induction platform 22, and the test platform 23 is connected to the fixing frame 2 through a second spring 9; a test probe 27 is installed on the test platform 23, and a sensor group 24 is installed on the induction platform 22; a side plate 8 is installed on the isolation box 4, a voltage regulating gear 11 is installed on the voltage regulator 10, a baffle 16 is installed on the side plate 8, longitudinal chutes 13 are opened on the isolation box 4 and the baffle 16, a rack 14 is slidably installed in the longitudinal chute 13 on the isolation box 4, a first inclined block 15 is slidably installed in the longitudinal chute 13 on the baffle 16, the rack 14 and the first inclined block 15 are in abutment through an inclined surface, and the rack 14 and the voltage regulating gear 11 are detachably connected, and a second inclined block 17 is installed on the first inclined block 15; the test platform 23 abuts against the second inclined block 17, and the test platform 23 can also be connected to the second inclined block 17; a push-button switch 30 is installed on the top of the test platform 23.

[0031] Specifically, a side plate 8 is installed on the isolation box 4, a side chute 12 is opened on the side plate 8, and the test platform 23 is slidably matched with the side chute 12.

[0032] Specifically, the sensor group 24 includes a smoke sensor and a flame sensor.

[0033] It should be noted that an electromagnetic chuck 25 is installed on the induction table 22. In the initial state, the electromagnetic chuck 25 is electrified, and the induction table 22 is connected to the test bench 23 through the electromagnetic chuck 25. The side wall of the test bench 23 is arranged as an inclined plane. Through the cooperation of the inclined plane on the test bench 23 and the second inclined plane block 17, the test bench 23 moves downward to push the second inclined plane block 17 and the first inclined plane block 15 to move; one side of the rack 14 close to the first inclined plane block 15 is arranged as an inclined plane. Through the cooperation of the inclined plane on the rack 14 and the first inclined plane block 15, the first inclined plane block 15 pushes the tooth surface of the rack 14 to move close to the pressure regulating gear 11 and meshes with the pressure regulating gear 11. During this process, the first inclined plane block 15 and the rack 14 are slidably matched through the guide groove 19 and the guide bar 20 to realize the connection between the first inclined plane block 15 and the rack 14.

[0034] When the present invention is in use, the transformer needs to be placed on the lifting table 6. The cylinder 3 drives the induction table 22 and the test bench 23 to move downward synchronously, so that the test probe 27 is connected to the transformer, and the voltage is increased by adjusting the voltage regulator 10; when the test voltage reaches the set value, the voltage is kept stable and the timing starts until the withstand voltage test ends.

[0035] During the downward movement of the induction table 22 and the test bench 23, through the cooperation of the inclined plane on the side wall of the test bench 23 and the second inclined plane block 17, the test bench 23 pushes the second inclined plane block 17 and the first inclined plane block 15 to move outward, so that the first inclined plane block 15 moves close to the rack 14. Through the cooperation of the inclined plane on the rack 14 and the first inclined plane block 15, the first inclined plane block 15 pushes the tooth surface of the rack 14 to move close to the pressure regulating gear 11 and meshes with the pressure regulating gear 11. During this process, the first inclined plane block 15 and the rack 14 are slidably matched through the guide groove 19 and the guide bar 20 to realize the connection between the first inclined plane block 15 and the rack 14.

[0036] The sensor group 24 of the present invention is used to detect whether the transformer catches fire or smokes. If the transformer catches fire during the pressure holding process, the flame sensor in the sensor group 24 detects the flame and controls the activation of the fire extinguisher 7. The fire extinguisher 7 extinguishes the fire on the transformer. During this process, the sensor group 24 detects the fire situation. If the fire is small and controllable, the electromagnetic chuck 28 is in a power-off state. At this time, the insertion block 32 is inserted into the card slot 18 under the rebounding action of the first spring 26, so that the test bench 23 is connected to the second inclined plane block 17.

[0037] The induction table 22 and the test table 23 are controlled by the air cylinder 3 to move upward. At the same time, the lifting table 6 lifts the transformer, so that the transformer moves upward at the same speed as the induction table 22 and the test table 23. During this process, the transformer is in a connected state with the test probe 27. During the upward movement of the test table 23, the test table 23 drives the rack 14 to move synchronously through the inclined block 15. Under the action of the meshing of the rack 14 and the voltage regulating gear 11, the upward movement of the test table 23 drives the voltage regulating gear 11 to rotate, thereby reducing the voltage of the detection circuit. Until the push switch 30 at the top of the test table 23 contacts the fixed frame 2, the detection circuit is powered off. The transformer is controlled to reset by the lifting table 6, so that the transformer is disconnected from the test probe 27, avoiding direct power-off of the detection circuit, resulting in an instantaneous mutation of the output voltage of the transformer, and further causing additional damage to the transformer under test. In the process of voltage reduction and power-off of the present invention, the lifting table 6 lifts the transformer, isolating the transformer from the ground, which can reduce the risk of electric shock caused by ground moisture or conductivity.

[0038] When the smoke sensor in the sensor group 24 detects that the transformer is smoking and not on fire, the decompression and power-off operation is the same as above.

[0039] See Figures 4-8 As shown in, a horizontal chute 31 is provided on the side wall of the test table 23. An insertion block 32 is slidably installed in the horizontal chute 31. The insertion block 32 is connected to the test table 23 through a spring 26. A metal plate 29 is installed on the insertion block 32, and an electromagnetic chuck 28 is installed at the bottom of the horizontal chute 31. The electromagnetic chuck 28 adsorbs the metal plate 29; a card slot 18 is provided on the inclined block 17. The test table 23 is connected to the inclined block 17 by inserting the insertion block 32 into the card slot 18.

[0040] It should be noted that if the transformer catches fire during the pressure holding process and the fire is relatively large, at this time, insulation breakdown or winding short circuit may have occurred inside the transformer, resulting in continuous combustion of the arc. Under the live state, the arc will continuously release energy, intensifying the fire. Therefore, it is necessary to cut off the power supply of the detection circuit urgently. By energizing the electromagnetic chuck 28, see Figure 5 As shown in, the metal plate 29 moves in the direction close to the electromagnetic chuck 28, so that the insertion block 32 disengages from the card slot 18 and slides into the horizontal chute 31, and the test table 23 is disconnected from the inclined block 17; then the electromagnetic chuck 1 is powered off, disconnecting the connection between the induction table 22 and the test table 23. At this time, the spring 9 resets, and the test table 23 quickly moves upward under the action of the spring 9. When the push switch 30 at the top of the test table 23 contacts the fixed frame 2, the detection circuit is powered off. When the fire is relatively large, the present invention skips the process of circuit voltage reduction and directly cuts off the power supply of the detection circuit, avoiding high-voltage combustion support and preventing the fire from further expanding due to electrification.

[0041] See Figures 4-8, a guide bar 20 is installed on the inclined surface of the rack 14, and a guide groove 19 is formed on the inclined surface of the first inclined surface block 15. The guide groove 19 is slidably connected to the guide bar 20.

[0042] The side wall of the test bench 23 is arranged as an inclined surface. Through the cooperation of the inclined surface on the test bench 23 and the second inclined surface block 17, the test bench 23 moves downward to push the second inclined surface block 17 and the first inclined surface block 15 to move; one side of the rack 14 close to the first inclined surface block 15 is arranged as an inclined surface. Through the cooperation of the inclined surface on the rack 14 and the first inclined surface block 15, the first inclined surface block 15 pushes the tooth surface of the rack 14 to move closer to the voltage regulating gear 11 and meshes with the voltage regulating gear 11. During this process, the first inclined surface block 15 and the rack 14 are slidably connected through the guide groove 19 and the guide bar 20.

[0043] See Figure 9 , a pressing plate 21 is horizontally and slidably installed in the longitudinal sliding groove 13, and the pressing plate 21 is connected to the inner wall of the isolation box 4 through a spring.

[0044] It should be noted that the pressing plate 21 presses against the rack 14 through the action of the spring, so that the rack 14 is in a separated state from the voltage regulating gear 11 in the initial state.

[0045] Please refer to Figures 4-10 As shown in the figure, the present invention is a method for testing the withstand voltage of a transformer. The method is applied to the transformer withstand voltage testing device as described in the above embodiment. The method includes the following steps: Step S1: Fix the transformer on the lifting table 6, drive the induction table 22 and the test bench 23 to move downward synchronously through the cylinder 3, connect the test probe 27 to the transformer, and boost the voltage by adjusting the voltage regulator 10; Step S2: When the test voltage reaches the set value, keep the voltage stable and start timing until the withstand voltage test ends; Step S3: During the downward movement of the induction table 22 and the test bench 23, through the cooperation of the inclined surface on the side wall of the test bench 23 and the second inclined surface block 17, the test bench 23 pushes the second inclined surface block 17 and the first inclined surface block 15 to move outward, so that the first inclined surface block 15 moves closer to the rack 14. Through the cooperation of the inclined surface on the rack 14 and the first inclined surface block 15, the first inclined surface block 15 pushes the tooth surface of the rack 14 to move closer to the voltage regulating gear 11 and meshes with the voltage regulating gear 11; Step S4: If the transformer catches fire during the pressure holding process, the flame sensor in the sensor group 24 detects the flame and controls the activation of the fire extinguisher 7, and the fire extinguisher 7 extinguishes the fire of the transformer; Step S5: The sensor group 24 detects the fire. If the fire is small and controllable, the electromagnetic chuck two 28 is powered off. At this time, the insertion block 32 is inserted into the card slot 18 under the rebounding action of the spring one 26, connecting the test bench 23 with the inclined plane block two 17. The cylinder 3 is used to control the induction bench 22 and the test bench 23 to move upward. At the same time, the lifting platform 6 lifts the transformer so that the transformer moves upward at the same speed as the induction bench 22 and the test bench 23. Step S6: During the upward movement of the test bench 23, the test bench 23 drives the rack 14 to move synchronously through the inclined plane block one 15. Under the meshing action of the rack 14 and the voltage regulating gear 11, the upward movement of the test bench 23 drives the voltage regulating gear 11 to rotate, thereby reducing the voltage of the detection circuit. Until the push-button switch 30 at the top of the test bench 23 contacts the fixed frame 2, the detection circuit is powered off. Step S7: The lifting platform 6 is used to control the transformer to reset, disconnecting the transformer from the test probe 27.

[0046] The implementation principle of the present invention is as follows: The transformer is fixedly placed on the lifting platform 6. The cylinder 3 is used to drive the induction bench 22 and the test bench 23 to move downward synchronously, connecting the test probe 27 to the transformer, and boosting the voltage by adjusting the voltage regulator 10. When the test voltage reaches the set value, the voltage is kept stable and the timing starts until the withstand voltage test ends.

[0047] During the downward movement of the induction bench 22 and the test bench 23, through the cooperation of the inclined plane on the side wall of the test bench 23 and the inclined plane block two 17, the test bench 23 pushes the inclined plane block two 17 and the inclined plane block one 15 to move outward, causing the inclined plane block one 15 to move in the direction close to the rack 14. Through the cooperation of the inclined plane on the rack 14 and the inclined plane block one 15, the inclined plane block one 15 pushes the tooth surface of the rack 14 to move in the direction close to the voltage regulating gear 11 and mesh with the voltage regulating gear 11. During this process, the inclined plane block one 15 and the rack 14 are slidably matched through the guide groove 19 and the guide bar 20 to realize the connection between the inclined plane block one 15 and the rack 14.

[0048] Specifically, the sensor group 24 can detect whether the transformer catches fire or smokes. If the transformer catches fire during the pressure holding process, the flame sensor in the sensor group 24 detects the flame and controls the activation of the fire extinguisher 7. The fire extinguisher 7 extinguishes the fire on the transformer. During this process, the sensor group 24 detects the fire. If the fire is small and controllable, the electromagnetic chuck two 28 is powered off. At this time, the insertion block 32 is inserted into the card slot 18 under the rebounding action of the spring one 26, connecting the test bench 23 with the inclined plane block two 17.

[0049] The induction table 22 and the test table 23 are controlled by the air cylinder 3 to move upward. At the same time, the lifting table 6 lifts the transformer, so that the transformer moves upward at the same speed as the induction table 22 and the test table 23. During this process, the transformer is in a connected state with the test probe 27. During the upward movement of the test table 23, the test table 23 drives the rack 14 to move synchronously through the inclined plane block 15. Under the action of the engagement between the rack 14 and the pressure regulating gear 11, the upward movement of the test table 23 drives the pressure regulating gear 11 to rotate, thereby reducing the voltage of the detection circuit. Until the push-button switch 30 at the top of the test table 23 contacts the fixed frame 2, the detection circuit is powered off. The transformer is controlled to reset by the lifting table 6, so that the transformer is disconnected from the test probe 27, avoiding direct power-off of the detection circuit, resulting in an instantaneous mutation of the output voltage of the transformer, and further causing additional damage to the transformer under test. In the process of voltage reduction and power-off of the present invention, the lifting table 6 lifts the transformer, isolating the transformer from the ground, which can reduce the risk of electric shock caused by wet or conductive ground.

[0050] If the transformer catches fire during the pressure holding process and the fire is large, at this time, insulation breakdown or winding short circuit may have occurred inside the transformer, resulting in continuous combustion of the arc. Under the live state, the arc will continuously release energy, intensifying the fire. Therefore, it is necessary to cut off the power supply of the detection circuit urgently. By energizing the electromagnetic chuck two 28, see Figure 5 , the metal plate 29 moves in the direction close to the electromagnetic chuck two 28, so that the insert block 32 disengages from the card slot 18 and slides into the transverse chute 31, and the test table 23 is disconnected from the inclined plane block two 17; then the electromagnetic chuck one 25 is powered off, disconnecting the connection between the induction table 22 and the test table 23. At this time, the spring two 9 resets, and the test table 23 quickly moves upward under the action of the spring two 9. When the push-button switch 30 at the top of the test table 23 contacts the fixed frame 2, the detection circuit is powered off. When the fire is large, the present invention skips the circuit voltage reduction process and directly cuts off the power supply of the detection circuit, avoiding high-voltage combustion support and preventing the fire from further expanding due to electrification.

[0051] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A withstand voltage test device for a transformer, characterized in that: It includes a base (1), on which a fixing frame (2) is installed. An isolation box (4) and a fixing frame (5) are installed inside the fixing frame (2). The fixing frame (5) is located at the bottom of the isolation box (4), and a fire extinguisher (7) is installed inside the fixing frame (5). A voltage regulator (10) is installed inside the isolation box (4). A lifting platform (6) is installed on the base (1). A cylinder (3) is installed on the fixing frame (2). An induction platform (22) is installed at the output end of the cylinder (3). The induction platform (22) is connected to a test platform (23) through an electromagnetic chuck one (25). The test platform (23) is located on top of the induction platform (22). The test platform (23) is connected to the fixing frame (2) through a spring two (9). A test probe (27) is installed on the test platform (23), and a sensor group (24) is installed on the induction platform (22). A side plate (8) is installed on the isolation box (4). A voltage regulating gear (11) is installed on the voltage regulator (10). A baffle (16) is installed on the side plate (8). Longitudinal sliding grooves (13) are opened on the isolation box (4) and the baffle (16). A rack (14) is slidably installed in the longitudinal sliding groove (13) on the isolation box (4). An inclined block one (15) is slidably installed in the longitudinal sliding groove (13) on the baffle (16). The rack (14) and the inclined block one (15) are in abutment through an inclined surface. The rack (14) and the voltage regulating gear (11) are detachably connected. An inclined block two (17) is installed on the inclined block one (15). The test platform (23) abuts against the inclined block two (17), and the test platform (23) can also be connected to the inclined block two (17). A push-button switch (30) is installed on the top of the test platform (23).

2. The withstand voltage testing device for a transformer according to claim 1, wherein: A side plate (8) is installed on the isolation box (4), and a side sliding groove (12) is opened on the side plate (8). The test platform (23) is in sliding fit with the side sliding groove (12).

3. The withstand voltage test device for a transformer according to claim 1, wherein: A guide bar (20) is installed on the inclined surface of the rack (14), and a guide groove (19) is opened on the inclined surface of the inclined block one (15). The guide groove (19) is slidably connected to the guide bar (20).

4. A withstand voltage testing device for a transformer according to claim 1, characterized in that: A pressing plate (21) is slidably installed horizontally in the longitudinal sliding groove (13), and the pressing plate (21) is connected to the inner wall of the isolation box (4) through a spring.

5. The withstand voltage testing device for a transformer according to claim 1, wherein: A horizontal sliding groove (31) is opened on the side wall of the test platform (23). An insertion block (32) is slidably installed in the horizontal sliding groove (31). The insertion block (32) is connected to the test platform (23) through a spring one (26). A metal plate (29) is installed on the insertion block (32). An electromagnetic chuck two (28) is installed at the bottom of the horizontal sliding groove (31), and the electromagnetic chuck two (28) adsorbs the metal plate (29). A card slot (18) is opened on the inclined block two (17). The test platform (23) is connected to the inclined block two (17) by inserting the insertion block (32) into the card slot (18).

6. The voltage withstand test device for a transformer according to claim 1, characterized in that: The sensor group (24) includes a smoke sensor and a flame sensor.

7. A method for withstand voltage testing of a transformer, characterized in that, The method is applied to the transformer withstand voltage test device as described in any one of the above claims 1-6. The method includes the following steps: Step S1: Fix the transformer on the lifting platform (6), drive the induction table (22) and the test table (23) to move downward synchronously through the air cylinder (3), connect the test probe (27) to the transformer, and boost the voltage by adjusting the voltage regulator (10). Step S2: When the test voltage reaches the set value, keep the voltage stable and start timing until the withstand voltage test ends. Step S3: During the downward movement of the induction table (22) and the test table (23), through the cooperation of the inclined plane on the side wall of the test table (23) and the second inclined plane block (17), the test table (23) pushes the second inclined plane block (17) and the first inclined plane block (15) to move outward, so that the first inclined plane block (15) moves closer to the rack (14). Through the cooperation of the inclined plane on the rack (14) and the first inclined plane block (15), the first inclined plane block (15) pushes the tooth surface of the rack (14) to move closer to the voltage regulating gear (11) and meshes with the voltage regulating gear (11). Step S4: If the transformer catches fire during the pressure holding process, the flame sensor in the sensor group (24) detects the flame and controls the activation of the fire extinguisher (7), and the fire extinguisher (7) extinguishes the fire on the transformer. Step S5: The sensor group (24) detects the fire situation. If the fire is small and controllable, the electromagnetic chuck two (28) is powered off. At this time, the plug block (32) is inserted into the card slot (18) under the rebound action of the first spring (26), connecting the test table (23) and the second inclined plane block (17). Control the induction table (22) and the test table (23) to move upward through the air cylinder (3), and at the same time, the lifting platform (6) supports the transformer, so that the transformer moves upward at the same speed as the induction table (22) and the test table (23). Step S6: During the upward movement of the test table (23), the test table (23) drives the rack (14) to move synchronously through the first inclined plane block (15). Under the action of the meshing of the rack (14) and the voltage regulating gear (11), the upward movement of the test table (23) drives the voltage regulating gear (11) to rotate, thereby reducing the voltage of the detection circuit until the push switch (30) at the top of the test table (23) contacts the fixed frame (2), and the detection circuit is powered off. Step S7: Control the transformer to reset through the lifting platform (6) to disconnect the transformer from the test probe (27).

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