Cooling device for transformer and control method

Abstract

The invention discloses a cooling device for a transformer and a control method, the cooling device comprises a hanging bracket, the hanging bracket comprises a cooling assembly, the cooling assembly comprises a plurality of groups of flow guide shells and vortex shells fixed on the inner ring surfaces of the flow guide shells, the axes of the spliced flow guide shells and the axes of the vortex shells are collinear, and air inlet pipes are arranged on the side walls of the flow guide shells in a penetrating manner; air flow penetrates through the flow guide shell and extends to the vortex shell, the air flow spirally ascends along the central axis of the vortex shell, the flow guide shell and the vortex shell can be installed at the bottom of a winding in a smaller space, and when air enters the flow disturbing shell and the vortex shell, the air flow generates vortex in the flow guide grooves through the flow guide plates and then is discharged from the flow guide holes. Therefore, the part of airflow spirally ascends along the inner side wall of the winding, the other part of airflow makes contact with the vortex shell and spirally ascends along the iron core part in the winding, the guiding effect of the airflow exhausted by the flow guide holes can be received in the process, and certain impact heat dissipation on a small gap between the iron cores is constantly kept.

Description

Technical Field

[0001] This invention relates to the field of hydraulic valve maintenance, and in particular to a cooling device and control method for transformers. Background Technology

[0002] During actual operation, electrical transformers inevitably generate various forms of energy consumption, resulting in significant energy loss. The main function of the cooling system is to gradually exchange the heat generated in the transformer with the outside environment, thereby gradually reducing the transformer's temperature rise and ensuring its normal operation.

[0003] Many transformers have cooling fans installed at the bottom. When the set start-up value is reached, the fans will start to gradually cool the transformer.

[0004] The existing excitation transformer has been in operation for over ten years. Due to the aging of its internal equipment, the temperature of the excitation transformer has been rising year by year. The continuously increasing transformer temperature reduces the withstand voltage and mechanical strength of the insulation material, which may reduce insulation or cause flashover, thus affecting the normal start-up and operation of the unit. The excitation transformer is located in a closed cabinet, and it is difficult to achieve a cooling effect by using an external temporary fan. If the temperature is too high for a long time, it will lead to damage to the excitation transformer, increasing repair costs. Furthermore, the heat dissipation modules of the existing dry-type transformer are insufficient to provide adequate cooling for the excitation transformer as they age. The limited space directly below the insulation sleeve of the excitation transformer makes it impossible to place a fan below to directly cool the interior of the excitation transformer. Moreover, the straight-up-down airflow is interrupted by the iron core inside the windings. Since the iron core is tightly fitted, the airflow cannot reach the small gaps between the iron cores, resulting in poor cooling effect. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is that the heat dissipation module of the existing dry-type transformer is insufficient to provide enough cooling for the excitation transformer as the service life increases. The space directly below the insulation sleeve of the excitation transformer is limited, so it is impossible to place a fan below to directly cool the inside of the excitation transformer by airflow. Furthermore, the straight up-down airflow cannot penetrate into the winding, which leads to poor cooling effect.

[0006] The above-mentioned technical problems are solved by the following technical solution: The present invention proposes a cooling device for transformers, which includes a cooling component, including several sets of guide shells and a vortex shell fixed in the inner annular surface of the guide shell. After the several sets of guide shells are spliced, their axes are collinear with the axis of the vortex shell. An air inlet pipe is provided through the side wall of the guide shell, and the airflow extends through the guide shell to the vortex shell. The airflow spirals upward along the central axis of the vortex shell.

[0007] In a preferred embodiment of the transformer cooling device of the present invention, the vortex shell contracts spirally in the axial direction.

[0008] In a preferred embodiment of the transformer cooling device of the present invention: a flow guide groove is provided inside the flow guide shell, and a plurality of flow guide plates are fixedly arranged inside the flow guide groove. The plurality of flow guide plates guide the flow in the same clockwise direction, and the flow guide shell is provided with flow guide holes at the end of the flow guide plates extending in the discharge direction.

[0009] In a preferred embodiment of the transformer cooling device of the present invention: the guide plate is inclined from bottom to top, and its side wall is attached to the side wall of the guide groove. The guide plate has a through hole on the side near the vortex shell.

[0010] In a preferred embodiment of the transformer cooling device of the present invention: the air inlet pipe is connected between two sets of guide plates, and includes an air inlet, and a first air outlet is provided on the side near the inclined lower end of the guide plate. A first wind baffle is provided at the air inlet of the first air outlet, and the first wind baffle is inclined towards the first air outlet.

[0011] In a preferred embodiment of the transformer cooling device of the present invention: the air inlet pipe further includes a second air outlet opened on the side close to the vortex shell, and a second wind baffle is provided on the side of the second air outlet away from the first air outlet. The second wind baffle is inclined and the guiding direction is the same clockwise direction as the guiding direction of the guide groove.

[0012] In a preferred embodiment of the transformer cooling device of the present invention: the end of the vortex shell away from the guide groove guides the airflow to the side away from the guide groove, and the airflow is inclined upward.

[0013] In a preferred embodiment of the transformer cooling device of the present invention, it further includes an installation assembly fixedly connected to the outer ring surface of the current guide shell, which includes a connecting plate connected to the outer ring surface of the current guide shell, a positioning plate cooperating with the connecting plate, and a clamping member provided at the end of the positioning plate away from the connecting plate.

[0014] In a preferred embodiment of the transformer cooling device of the present invention: a plurality of sliding grooves are provided through the surface of the connecting plate; a plurality of sliding rods are fixedly provided on the positioning plate and the sliding rods are fixedly locked by nuts; a rotating groove is provided on the positioning plate; the clamping member includes two sets of rotating rods that slide in the rotating groove; clamping rings are fixedly connected to both ends of the two sets of rotating rods; and the two sets of opposing clamping rings are fixedly locked by screws.

[0015] Another object of the present invention is to provide a control method that aims to solve the problem.

[0016] To solve the above-mentioned technical problems, the present invention also provides the following technical solution: a control method, comprising a cooling device for a transformer; and, fabricating a suitable steel frame and fixing several cooling fans to the ground of the excitation transformer without damaging the original equipment, using suitable insulation testing tools to test the insulation performance of the cooling fans to ensure that the insulation resistance and absorption ratio meet the preset standards, fastening the steel frame and fans to the corresponding phases of the excitation transformer to reduce vibration, and the fans delivering airflow to the air inlet through a sealed pipe connection, selecting a power switch with a capacity greater than the power of the cooling fans; installing a temperature control box at a suitable location in the excitation transformer cabinet and laying cables, and after wiring and debugging, recording the automatic start-up status of the cooling fans and the temperature change of the excitation transformer.

[0017] The beneficial effects of the control method of the present invention are as follows: the guide shell and the vortex shell can be installed at the bottom of the winding in a smaller space, so that heat can be dissipated from bottom to top in the direction of the winding axis. At the same time as the vortex shell and the vortex shell are inlet, the airflow generates vortices in the guide plate in the guide groove and then exits from the guide hole, so that part of the airflow spirals up along the inner side wall of the winding, and another part of the airflow contacts the vortex shell and spirals up along the iron core part inside the winding. In this process, the airflow discharged from the guide hole can be guided, and a certain impact heat dissipation is maintained on the small gap between the iron cores at all times. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments of the present invention will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention. Wherein: Figure 1 A schematic diagram showing the interaction between the transformer cooling device and the transformer is shown. Figure 2 A schematic diagram of the overall structure of the transformer cooling device is shown. Figure 3 A top cross-sectional view of the transformer cooling system is shown. Figure 4 This shows a split view of the guide plates at both ends of the guide channel along the wind direction in the transformer cooling device; Figure 5 A detailed cross-sectional view of the transformer cooling device is shown; Figure 6 A detailed cross-sectional view of the air inlet duct in the transformer cooling system is shown; Figure 7 A split schematic diagram of the components installed in the transformer cooling system is shown.

[0019] Figure 8 A side view of the flow guide shell in a transformer cooling device is shown; Figure 9The diagram shows the effect of airflow generated by the guide shell and vortex shell in the transformer cooling device on the iron core; Figure 10 A schematic diagram of the fan installation in a transformer cooling system is shown. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0021] The terminology used in this invention is that which is currently widely used in the art in consideration of the function of the invention; however, these terms may vary according to the intent of those skilled in the art, precedent, or new technology in the art. Furthermore, specific terms may be chosen by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the invention. Therefore, the terms used in this specification should not be construed as simple names, but rather based on their meanings and the overall description of the invention.

[0022] Reference Figures 1-10 This embodiment provides a transformer cooling device, including a cooling assembly 1, comprising several sets of guide shells 11 and eddy current shells 12 fixed on the inner annular surface of the guide shells 11. It is noted that the guide shells 11 and eddy current shells 12 are designed to fit into the bottom of the winding. Since the gap between the winding and the bottom pad is small in the field, conventional cooling fans are difficult to place at the bottom of the winding. Therefore, careful attention needs to be paid to the dimensions when designing the guide shells 11 and eddy current shells 12. After the several sets of guide shells 11 are spliced ​​together, their axes are collinear with the axes of the eddy current shells 12. A splicing method is used here. Figure 1As shown, since the iron core inside the winding extends downwards and occupies a large space below, a splicing and internal hollowing method can be used to better place it below the winding. The splicing method can use bolts on both sides or other fixing methods, ensuring the internal connectivity of the guide shell 11. The fixing method is not specifically limited here. An air inlet pipe 13 is provided through the side wall of the guide shell 11. The air inlet pipe 13 is used to receive the airflow transmitted by the fan, and the airflow extends through the guide shell 11 to the vortex shell 12. The airflow spirals upwards along the central axis of the vortex shell 12, and the vortex shell 12 spirals and contracts towards the axis. During the spiral upward process, it can be ensured that the airflow always flows towards the winding. The iron core at the central axis of the winding is cooled by air blowing, and the airflow is always directed towards the center of the iron core, which greatly increases the amount of airflow entering the gap between the iron cores. At the same time, the airflow discharged from the guide shell 11 can always contact the inner circumferential side wall of the winding. Since the space at the bottom of the winding is limited, the airflow generated by the guide shell 11 always rises along the inner circumferential side wall of the winding, which can generate a spiral airflow at all times. After a certain vortex generated in the center of the vortex shell 12 is decomposed by the iron core on the central axis of the winding, the airflow generated by the guide shell 11 on the outer side of the winding and adhering to the inner side wall of the winding can always conduct the vortex to the vortex shell 12 in the center.

[0023] The design adopts a "multi-group flow guide shell splicing + hollow vortex shell" design, which does not require occupying a large amount of space at the bottom of the winding. "The space below the excitation transformer insulation sleeve is limited, and conventional fans cannot be placed there." It can be directly embedded into the bottom of the winding, which is suitable for on-site installation conditions.

[0024] Specifically, the flow guide shell 11 has a flow guide groove 111 inside, and several sets of flow guide plates 112 are fixedly installed inside the flow guide groove 111. The several sets of flow guide plates 112 guide the flow in the same clockwise direction. The clockwise direction specifically refers to clockwise and counterclockwise. The term "clockwise direction" in the following text is the same as described here. The flow guide shell 11 has a flow guide hole 113 at the end of the flow guide plate 112 extending in the discharge direction. The flow guide hole 113 should fit tightly with the flow guide plate 112 at the connection point and the transition should be smooth. This can ensure that the airflow can achieve stable discharge and will not suffer significant loss during the discharge process.

[0025] Specifically, the guide plate 112 is inclined from bottom to top to ensure that the airflow flows from bottom to top, and its sidewall is in close contact with the sidewall of the guide groove 111 to prevent some airflow from being stored inside the guide shell 11 and unable to be discharged. The guide plate 112 has a through hole a on the side near the vortex shell 12. When the airflow enters the interior of the guide shell 11, the airflow will pass through several sets of guide plates 112 in a clockwise direction. When passing through any set of guide plates 112, part of the airflow will rise along the inclined surface of the guide plate 112 and finally... The airflow is discharged into the winding through the guide hole 113, where it dissipates heat to the iron core and excitation transformer. Another part of the airflow passes through the through hole a and reaches the guide plate 112 behind it. It rises on the inclined surface of the guide plate 112 and is discharged through the guide hole 113. Some of the airflow will continue backward until all the guide plates 112 are in contact with the airflow and the airflow is discharged from above the guide hole 113. The through hole a of the last set of guide plates 112 should be sealed, or the last set of guide plates 112 should not have a through hole a.

[0026] It should be noted that the several sets of guide plates 112 are arranged clockwise or counterclockwise. When the airflow is sufficient, the size of the through hole a can be set to the same size. If the airflow is insufficient, it is recommended to set the size of the through hole a to gradually increase. The through hole a of the several sets of through holes a should be set to the largest size in the clockwise direction from the first through hole a, and the diameter of the subsequent through holes a should decrease in sequence. The through hole a of the second to last set of guide plates 112 should be the smallest diameter. The through hole a of the last set of guide plates 112 should be sealed or not set. This can ensure that although the airflow is at its maximum when the airflow reaches the first set of guide plates 112, the airflow is lost more due to the large through hole of the guide plate 112. This makes the airflow contacted on each subsequent guide plate 112 approximately equal. This can better ensure that the airflow discharged from each guide hole 113 is approximately uniform, which makes it easier to ensure the spiral stability of the airflow.

[0027] The air inlet duct 13 is connected between two sets of guide plates 112. It includes an air inlet 131 and a first air outlet 132 is provided on the side near the lower inclined end of the guide plate 112. A first wind baffle 133 is provided at the air inlet of the first air outlet 132. The first wind baffle 133 is inclined towards the first air outlet 132. This ensures that some of the air entering the air inlet duct 131 will reach the first wind baffle 133. After contacting the inclined surface of the first wind baffle 133, it will be guided into the guide groove 111 of the guide shell 11 and flow circumferentially.

[0028] Furthermore, the air inlet duct 13 also includes a second air outlet 134 located near the vortex shell 12. A second baffle 135 is provided on the side of the second air outlet 134 away from the first air outlet 132. The second baffle is inclined, and its guiding direction is clockwise with that of the guiding channel 111. This ensures that the remaining airflow after not contacting the first baffle 133 flows along the second baffle 135 and enters the vortex shell 12, flowing along the side wall of the vortex shell 12. The end of the vortex shell 12 away from the guiding channel 111 guides the airflow towards the side away from the guiding channel 111, and the airflow is inclined upwards. Figure 8 The airflow direction of the vortex shell 12 shown is towards the central axis of the vortex shell 12. This generates vortices that impact the gap between the iron cores. It should be noted that the airflow generated by the vortex shell 12 is in constant contact with the iron core, and the iron core will provide some turbulence, preventing the airflow from flowing upward in the vortex direction. At this time, the airflow generated by the vortex shell 12 and the airflow generated by the guide plate 112 are in the same direction. When the airflow generated by the vortex shell 12 is affected, the vortex generated at the guide plate 112 does not change its shape because it is in contact with the inner ring surface of the winding. At this time, the airflow generated by the guide plate 112 can ensure that the airflow generated by the vortex shell 12 will return to the original vortex state when it encounters the resistance of the iron core. This ensures that the airflow can enter from the side at all times through the gap between the iron cores, which can greatly improve the continuous impact and heat dissipation of the small gap between the iron cores.

[0029] Through "dual airflow path + vortex entrainment" - the airflow of the guide shell 11 spirals up along the winding side wall (stable and not disturbed by the iron core), and the airflow of the vortex shell rises along the iron core. The former drives the latter to restore the vortex shape through the entrainment effect, avoiding the discontinuity of airflow and ensuring the continuous impact on the iron core gap. "The straight up and down airflow is cut off by the iron core and cannot penetrate the gap."

[0030] The inclined guide plate 112 inside the guide groove 111 with through hole a design (the diameter of the through hole can be gradually changed) can make the airflow evenly discharged from each guide hole, avoiding local excess or insufficient airflow. At the same time, the structure of the vortex shell "contracting towards the axis" forces the airflow to converge towards the center of the iron core, specifically solving the problems of "uneven airflow distribution and local overheating".

[0031] The "dual air outlets + baffle" design of the air inlet duct 13 (the first air outlet supplies air to the guide channel, and the second air outlet supplies air to the vortex shell) achieves a reasonable distribution of air volume—ensuring the stability of the spiral airflow on the side wall and providing sufficient airflow to the iron core area. At the same time, the "tilted upward + contracted towards the axis" guidance of the vortex shell further enhances the penetration of the airflow into the iron core gap.

[0032] Furthermore, it also includes a mounting assembly 3 fixedly connected to the outer annular surface of the guide shell 11. Since there is a bracket below the insulating sleeve of the winding, the guide shell 11 can be fixedly mounted on the bracket below the winding through the mounting assembly 3. It includes a connecting plate 31 connected to the outer annular surface of the guide shell 11, a positioning plate 32 connected to the connecting plate 31, a clamping member 33 provided at the end of the positioning plate 32 away from the connecting plate 31, and a number of sliding grooves 311 through the surface of the connecting plate 31. The size of the sliding grooves 311 should be larger than the size of the sliding rod 321. The surface of the sliding rod 321 should have threaded protrusions. The size of the nut that is threadedly connected to the sliding rod 321 should be larger than the size of the sliding grooves 311 to ensure that the side of the nut abuts against both ends of the sliding grooves 311. On the side wall of the connecting plate 31, the flow guide shell 11 can slide on the sliding groove 311 of the connecting plate 31 to adjust its height. Several sets of sliding rods 321 are fixedly provided on the positioning plate 32 of the rotating groove 322. The sliding rods 321 can slide to adjust the clamping position of the clamping member 33, so as to adapt to more types of winding bottom supports. The sliding rods 321 are fixedly locked by nuts. The clamping member 33 includes two sets of rotating rods 331 that slide in the rotating groove 322. Both ends of the two sets of rotating rods 331 are fixedly connected to clamping rings 332. The two sets of opposing clamping rings 332 are fixedly locked by the cooperation of screws and nuts. The specific fixing and locking method is not specifically limited here.

[0033] Furthermore, a suitable steel frame was fabricated and several cooling fans were fixed to the ground of the excitation transformer without damaging the original equipment. The insulation performance of the cooling fans was tested using suitable insulation testing tools to ensure that the insulation resistance and absorption ratio met the preset standards. The steel frame and fans were fastened to the corresponding phases of the excitation transformer to reduce vibration. The fans were connected to the air inlet 131 through a sealed pipe. A power switch with a capacity greater than that of the cooling fans was selected. A temperature control box was installed in a suitable position in the excitation transformer cabinet and cables were laid. After wiring and debugging, the automatic start-up status of the cooling fans and the temperature change of the excitation transformer were recorded.

[0034] Specifically, this embodiment refers to Figure 10 Fabricate a steel frame for the fixed cooling fans, take on-site measurements to ensure that there are 6 fans, specifically for the heat dissipation windings, which can be fixed to the ground of the excitation transformer without damaging the original equipment.

[0035] Includes the following steps: After on-site analysis of the screw and steel frame locations, it was decided to arrange the components on the bottom steel frame, with a total of two steel frames, each equipped with three cooling fans. Figure 10In this embodiment, M represents the fan motor, and the quantity is set to 6 sets. QF represents the miniature circuit breaker, and the quantity is set to 1 set. KM1 and KM2 are both AC contactors, and the quantity is 1 set each. FU1, FU2, and FU3 are all fuses, and each is 1 set. K represents the temperature control box contact, and it is set to 1 set.

[0036] Secondly, the insulation performance of the cooling fan is tested, including the following steps: Test the insulation resistance of the cooling fan with a 1000V megohmmeter; it should not be less than 30MΩ. Otherwise, the insulation resistance of the cooling fan is too low and it cannot be put into use. Read the insulation resistance values ​​R15 and R60 at 15s and 60s, respectively, and calculate the absorption ratio R60 / R15. An insulation resistance of not less than 30MΩ is considered qualified, and an absorption ratio of not less than 1.3 is considered qualified.

[0037] Install the cooling fan and steel frame, securing them to the ground around the excitation transformer, ensuring no damage to existing equipment. This includes the following steps: Connect and secure the steel frame to the ground. After securing it, install the cooling fan directly below the three phases and fix it to the steel frame. Ensure the installation is tight to reduce vibration.

[0038] Next, determine the power supply for the cooling fan. The principle is that the power switch capacity should be greater than the cooling fan's power to prevent overload tripping after the cooling fan is turned on. This includes the following steps: Secondly: The cooling fan has a power of 90W. Based on the instantaneous current measured during the test start-up and the current of the components inside the temperature control box, it was decided to use a 16A circuit breaker. Finally, the air from the cooling fan completely enters the air inlet pipe 13 through the connecting pipe. The cooling fan temperature control box should be installed on the excitation transformer cabinet for easy wiring and convenient inspection by operation and maintenance personnel. The installation includes the following steps: After installing and securing the excitation transformer in a suitable location on the excitation transformer cabinet, pull the cable into the temperature control box.

[0039] Wiring and debugging were performed, and records were kept of whether the cooling fan would start automatically when the set value for starting the cooling fan was reached after the installation, and whether the temperature of the excitation transformer would decrease after starting.

[0040] Finally, it should be noted that the methods and devices described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways as long as they do not depart from the scope of the present invention.

Claims

1. A cooling device for a transformer, characterized in that: include, The cooling assembly (1) includes several sets of guide shells (11) and a vortex shell (12) fixed inside the guide shell (11). After the several sets of guide shells (11) are spliced ​​together, their axes are collinear with the axes of the vortex shell (12). An air inlet pipe (13) is provided through the side wall of the guide shell (11), and the airflow extends through the guide shell (11) to the vortex shell (12). The airflow spirals upward along the central axis of the vortex shell (12).

2. The transformer cooling device according to claim 1, characterized in that: The vortex shell (12) contracts spirally in the axial direction.

3. The transformer cooling device according to claim 1 or 2, characterized in that: The flow guide shell (11) has a flow guide groove (111) inside, and a number of flow guide plates (112) are fixedly installed inside the flow guide groove (111), and the number of flow guide plates (112) guide the flow in the same clockwise direction. The guide shell (11) has a guide hole (113) extending in the discharge direction at the end of the guide plate (112).

4. The transformer cooling device according to claim 3, characterized in that: The guide plate (112) is inclined from bottom to top, and its side wall is attached to the side wall of the guide groove (111). The guide plate (112) has a through hole (a) on the side near the vortex shell (12).

5. The transformer cooling device according to claim 4, characterized in that: The air inlet pipe (13) is connected between two sets of guide plates (112). It includes an air inlet (131) and a first air outlet (132) is provided on the side near the lower end of the guide plate (112). A first wind baffle (133) is provided at the air inlet of the first air outlet (132). The first wind baffle (133) is inclined towards the first air outlet (132).

6. The transformer cooling device according to claim 5, characterized in that: The air inlet pipe (13) also includes a second air outlet (134) opened on the side near the vortex shell (12). The second air outlet (134) is provided with a second wind baffle (135) on the side away from the first air outlet (132). The second wind baffle is inclined and the flow direction is the same clockwise direction as the flow direction of the flow channel (111).

7. The transformer cooling device according to claim 6, characterized in that: The vortex shell (12) at the end away from the guide groove (111) guides the airflow to the side away from the guide groove (111), and the airflow is inclined upward.

8. The transformer cooling device according to any one of claims 1 to 7, characterized in that: It also includes an installation assembly (3) that is fixedly connected to the outer ring surface of the flow guide shell (11), which includes a connecting plate (31) connected to the outer ring surface of the flow guide shell (11), and a positioning plate (32) that is connected to the connecting plate (31). A clamping member (33) is provided at the end of the positioning plate (32) away from the connecting plate (31).

9. The transformer cooling device according to claim 8, characterized in that: The connecting plate (31) has several sets of sliding grooves (311) through it, and the positioning plate (32) has several sets of sliding rods (321) fixedly installed on it. The sliding rods (321) are fixed and locked by nuts. The positioning plate (32) has a rotating groove (322). The clamping member (33) includes two sets of rotating rods (331) that slide in the rotating groove (322). Both ends of the two sets of rotating rods (331) are fixedly connected to clamping rings (332), and the two sets of opposing clamping rings (332) are fixed and locked by screws.

10. A control method, characterized in that: The cooling device for transformers as described in any one of claims 1 to 9; and, to manufacture a suitable steel frame and fix a plurality of cooling fans to the ground of the excitation transformer without damaging the original equipment; Use appropriate insulation testing tools to test the insulation performance of the cooling fan to ensure that the insulation resistance and absorption ratio meet the preset standards; The steel frame and fan are fastened to the corresponding phase below the excitation transformer to reduce vibration, and the fan delivers airflow to the air inlet (131) through a sealed pipe connection. Select a power switch with a capacity greater than that of the cooling fan, install a temperature control box in a suitable location in the excitation transformer cabinet and lay cables; after wiring and debugging, record the automatic start-up status of the cooling fan and the temperature change of the excitation transformer.

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