Dry-type voltage transformer with temperature measurement

Abstract

This invention discloses a temperature-measurable dry-type voltage transformer, belonging to the technical field of voltage transformers. It includes a mounting base, an insulating housing, terminals, and a transformer assembly. The insulating housing and terminals are fixedly connected to the upper end of the mounting base, and the transformer assembly is connected to the terminals via wires. An equipment compartment is also fixedly connected to the upper end of the mounting base, and a mounting shell is fixedly connected to the upper end of the equipment compartment. A cooling assembly for cooling the interior of the insulating housing is installed inside the mounting shell. In use, a temperature sensor can monitor the temperature inside the insulating housing in real time. When the temperature inside the insulating housing increases, the negative pressure piston and the pushing piston in the negative pressure tube will repeatedly move up and down, thereby drawing coolant from the storage tube and circulating it within the cooling tube. This allows the invention to cool the interior of the insulating housing without additional power, thus preventing damage to the voltage transformer due to excessively high internal temperatures.

Description

Technical Field

[0001] This invention relates to the field of voltage transformer technology, specifically a dry-type voltage transformer capable of measuring temperature. Background Technology

[0002] The main function of a voltage transformer is to convert high-voltage signals into standardized, measurable low-voltage signals. In this way, the voltage values ​​of high-voltage systems can be safely introduced into low-voltage instruments, relay protection devices, and automation equipment, facilitating the measurement, monitoring, and analysis of the power grid voltage.

[0003] The core structure of dry-type voltage transformers of 35kV and below is to solidify the high and low voltage windings wound on silicon steel cores into a whole through vacuum casting epoxy resin process, and then add an external insulating shell, terminals and base to form a safe, reliable and maintenance-free measurement and protection device.

[0004] However, the aforementioned epoxy resin-encapsulated voltage transformers offer virtually no heat dissipation during use and cannot monitor internal temperature changes in real time. Furthermore, voltage transformers continuously generate heat during operation. Currently, heat dissipation methods typically involve natural cooling or the use of cooling fans. Neither natural cooling nor fan cooling effectively dissipates heat from the inside of the voltage transformer, leading to insufficient heat dissipation. Over time, this results in damage to the internal structure of the voltage transformer. Once damaged, epoxy resin-encapsulated voltage transformers can only be replaced, not repaired. Therefore, this invention provides a temperature-measurable dry-type voltage transformer to solve the aforementioned problems. Summary of the Invention

[0005] The purpose of this invention is to provide a dry-type voltage transformer capable of measuring temperature, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A temperature-measurable dry-type voltage transformer includes a mounting base, an insulating housing, terminals, and a transformer assembly. The insulating housing and terminals are both fixedly connected to the upper end of the mounting base, and the transformer assembly is connected to the terminals via wires. An equipment compartment is also fixedly connected to the upper end of the mounting base, and a mounting shell is fixedly connected to the upper end of the equipment compartment. A cooling assembly for cooling the interior of the insulating housing is installed inside the mounting shell.

[0008] The transformer assembly includes several steel sheets stacked together. Several inner coils are wound around the outside of the steel sheets. An insulating layer is wound around the outside of the inner coils. A temperature sensor is inserted inside the insulating layer. An insulating sleeve is also provided inside the insulating shell to protect the transformer assembly.

[0009] As a further embodiment of the present invention, a plurality of outer coils are wound around the outside of the insulating layer, and the temperature sensor is located between the inner coil and the outer coil, and the temperature sensor is electrically connected to the inner coil.

[0010] As a further embodiment of the present invention, an isolation sleeve is also provided inside the isolation shell, and the steel sheet, inner coil, insulation layer and outer coil are all located inside the isolation sleeve. The output line of the temperature sensor is also electrically connected to the control motherboard inside the equipment compartment. A power supply battery is also installed inside the equipment compartment, and insulating resin is filled between the isolation shell and the isolation sleeve.

[0011] As a further embodiment of the present invention, the cooling component includes a temperature difference box, which is fixedly connected to the upper end of the equipment compartment, and the equipment compartment is filled with helium. A plurality of heat-conducting columns are fixedly connected inside the isolation sleeve, and the ends of the heat-conducting columns away from the isolation sleeve are all inserted into the temperature difference box.

[0012] As a further embodiment of the present invention, a negative pressure pipe is fixedly connected to the upper end of the temperature difference box, and a cooling pipe is connected to the outside of the negative pressure pipe. The end of the cooling pipe away from the negative pressure pipe is coiled inside the steel sheet. A liquid storage pipe is installed on the outer wall of the isolation shell. The liquid storage pipe is filled with coolant, and several first cooling fins are fixedly connected to the outer wall of the liquid storage pipe. The outlet of the liquid storage pipe is connected to the negative pressure pipe through a pipe, and the return end of the cooling pipe is also connected to the liquid storage pipe.

[0013] As a further embodiment of the present invention, two power pipes are symmetrically fixedly connected to the upper end of the temperature difference box. The power pipes are located on both sides of the negative pressure pipe, and the two power pipes are respectively connected to the negative pressure pipe through a guide pipe. A one-way valve is installed in the guide pipe. The one-way valve in the guide pipe only allows air in the negative pressure pipe to enter the power pipe. A conduction column is fixedly connected inside the power pipe. The end of the conduction column away from the power pipe is inserted into the temperature difference box. A cold pressing block is movably connected inside the power pipe. A pull rod is fixedly connected to the upper end of the cold pressing block. The upper end of the pull rod slides through the top end of the power pipe.

[0014] As a further embodiment of the present invention, two flow holes are opened at the bottom of the inner side of the negative pressure pipe, and a one-way valve is installed in each of the two flow holes. A negative pressure piston is slidably connected inside the negative pressure pipe. An inner rod is fixedly connected to the upper end of the negative pressure piston. An outer column is slidably sleeved on the outer side of the inner rod. A pushing piston is fixedly connected to the lower end of the outer column, and the pushing piston is located above the negative pressure piston. A ventilation hole is also opened on the inner wall of the negative pressure pipe, and a one-way valve is also installed in the ventilation hole. The one-way valve in the ventilation hole only allows outside air to enter the negative pressure pipe. A magnetic ring is fixedly connected to the end of the pushing piston and the negative pressure piston that are close to each other, and the two magnetic rings repel each other. Several second cooling fins are fixedly connected to the outer wall of the negative pressure pipe.

[0015] As a further embodiment of the present invention, a reset tube is fixedly connected to the upper end of the negative pressure tube, a lower power chamber is opened in the reset tube, an upper power chamber is opened at the upper end of the lower power chamber, the upper power chamber and the lower power chamber are connected through a flow channel, the outer column is slidably connected in the lower power chamber, and a pressure plug is fixedly connected to the end of the inner rod away from the negative pressure piston.

[0016] As a further embodiment of the present invention, the pressure plug is slidably connected in the upper power chamber, and a return spring is fixedly connected to the top of the upper power chamber. The upper end of the pull rod is fixedly connected to the pressure plug by a pull rope.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. When the voltage transformer of the present invention is in use, the temperature inside the isolation shell can be monitored in real time by a temperature sensor. When the temperature inside the isolation shell rises significantly, the staff can detect it in time and take targeted measures to avoid the voltage transformer burning out.

[0019] 2. When the present invention is in use, the voltage transformer will continuously generate heat during use. At this time, the temperature inside the isolation sleeve will increase significantly. Then, the negative pressure piston and the pushing piston inside the negative pressure tube will move up and down repeatedly, thereby drawing the coolant in the storage tube and circulating it in the cooling tube. This allows the present invention to cool the inside of the isolation sleeve without the need for additional power, thereby preventing the voltage transformer from being damaged due to excessively high internal temperature of the isolation sleeve. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a dry-type voltage transformer capable of measuring temperature.

[0021] Figure 2 This is a split diagram of a temperature-measurable dry-type voltage transformer.

[0022] Figure 3This is a split view of the transformer assembly in a temperature-measurable dry-type voltage transformer.

[0023] Figure 4 This is a structural diagram of a cooling component in a temperature-measurable dry-type voltage transformer.

[0024] Figure 5 This is a structural diagram of the negative pressure tube and the power tube in a dry-type voltage transformer capable of measuring temperature.

[0025] Figure 6 This is a cross-sectional view of the negative pressure tube and the power tube in a temperature-measurable dry-type voltage transformer.

[0026] Figure 7 In a dry-type voltage transformer capable of measuring temperature Figure 6 Enlarged diagram of point A in the middle.

[0027] In the diagram: 1. Mounting base; 2. Isolation housing; 3. Terminal block; 4. Mounting housing; 5. Equipment compartment; 6. Isolation sleeve; 7. Transformer assembly; 8. Cooling assembly;

[0028] 700, Steel sheet; 701, Inner coil; 702, Insulation layer; 703, Outer coil; 704, Temperature sensor; 800, Temperature difference box; 801, Liquid storage tube; 802, First cooling fin; 803, Negative pressure tube; 804, Power tube; 805, Heat conduction column; 806, Second cooling fin; 807, Conduction column; 808, Cold pressing block; 809, Tie rod; 810, Flow guide tube;

[0029] 812. Negative pressure piston; 813. Push piston; 814. Magnet ring; 815. Inner rod; 816. Reset tube; 817. Outer column; 818. Pull rope; 819. Upper power chamber; 820. Lower power chamber; 821. Reset spring; 822. Guide channel; 823. Pressure plug; 824. Sealing bellows; 825. Cooling pipe; 826. Flow hole. Detailed Implementation

[0030] 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.

[0031] Example 1: Reading Figures 1-3In this embodiment of the invention, a dry-type voltage transformer capable of measuring temperature includes a mounting base 1, an insulating shell 2, a terminal block 3, and a transformer assembly 7. The insulating shell 2 and the terminal block 3 are both fixedly connected to the upper end of the mounting base 1, and the transformer assembly 7 is connected to the terminal block 3 via wires. Specifically, the voltage transformer is prior art, and the connection between the transformer assembly 7 and the terminal block 3 is also prior art, and will not be described in detail here. The upper end of the mounting base 1 is also fixedly connected to an equipment compartment 5, and the upper end of the equipment compartment 5 is fixedly connected to a mounting shell 4. A cooling assembly 8 for cooling the interior of the insulating shell 2 is installed inside the mounting shell 4.

[0032] The transformer assembly 7 includes several steel sheets 700 stacked together. The steel sheets 700 are silicon steel sheets. Several inner coils 701 are wound around the outside of each steel sheet 700. An insulating layer 702, which is insulating paper, is wound around the outside of each inner coil 701. A temperature sensor 704 is inserted inside the insulating layer 702. Several outer coils 703 are also wound around the outside of the insulating layer 702. The temperature sensor 704 is located between the inner coils 701 and the outer coils 703, and is electrically connected to the inner coils 701. An insulating sleeve 6 is also provided inside the insulating shell 2. The steel sheets 700, inner coils 701, and outer coils 703 are connected to the inner coils 701. The coil 701, the insulating layer 702, and the outer coil 703 are all located inside the insulating sleeve 6. The inner coil 701 is a low-voltage coil that powers the temperature sensor 704 without burning it out. The output line of the temperature sensor 704 is also electrically connected to the control mainboard inside the equipment compartment 5. A power supply battery is also installed inside the equipment compartment 5. The control mainboard is also equipped with a wireless communication module, which facilitates signal transmission by the temperature sensor 704. The power supply battery provides temporary power when the inner coil 701 cannot power the temperature sensor 704. Insulating resin is also filled between the insulating outer shell 2 and the insulating sleeve 6.

[0033] Example 2: Please refer to Figure 2 and Figure 4 The cooling component 8 includes a temperature difference box 800, which is fixedly connected to the upper end of the equipment compartment 5. The equipment compartment 5 is filled with helium gas, which has high thermal conductivity. A plurality of heat-conducting columns 805 are fixedly connected inside the isolation sleeve 6. The ends of the heat-conducting columns 805 away from the isolation sleeve 6 are inserted into the temperature difference box 800. The plurality of heat-conducting columns 805 pass through the isolation sleeve 6, the insulating resin and the isolation shell 2 in sequence, and the temperature inside the isolation sleeve 6 can be transferred to the temperature difference box 800 through the heat-conducting columns 805.

[0034] Please see Figure 4 and Figure 5The upper end of the temperature difference box 800 is fixedly connected to a negative pressure pipe 803, and a cooling pipe 825 is connected to the outside of the negative pressure pipe 803. The end of the cooling pipe 825 away from the negative pressure pipe 803 is coiled inside the steel sheet 700 (see details). Figure 2 The hot air inside the insulating sleeve 6 can be cooled by the cooling pipe 825. A liquid storage pipe 801 is installed on the outer wall of the insulating outer shell 2. The liquid storage pipe 801 is filled with coolant, and several first cooling fins 802 are fixedly connected to the outer wall of the liquid storage pipe 801. The first cooling fins 802 can cool the coolant in the liquid storage pipe 801. It is worth noting that the coolant itself has highly efficient heat exchange characteristics. After absorbing heat and flowing back into the liquid storage pipe 801, the coolant exchanges heat with the outside air. The fins 802 can further increase the heat exchange rate of the coolant. The internal temperature of the voltage transformer is much higher than the outside air temperature during use. When the coolant returns to the storage pipe 801, it will cool down. Therefore, there is no need to add an additional heat dissipation structure, such as a cooling fan. The outlet of the storage pipe 801 is connected to the negative pressure pipe 803 through a pipe, and the return end of the cooling pipe 825 is also connected to the storage pipe 801. Through the cooperation of the negative pressure pipe 803, the storage pipe 801 and the cooling pipe 825, the coolant can circulate in the isolation shell 2.

[0035] Please see Figure 5 and Figure 6 The upper end of the temperature difference box 800 is symmetrically and fixedly connected to two power pipes 804. The power pipes 804 are located on both sides of the negative pressure pipe 803, and the two power pipes 804 are respectively connected to the negative pressure pipe 803 through guide pipes 810. A one-way valve is installed in the guide pipe 810, which only allows air in the negative pressure pipe 803 to enter the power pipe 804. A conductive column 807 is fixedly connected inside the power pipe 804. The conductive column 807 is made of graphite. Made of a material, the end of the conductive column 807 away from the power tube 804 is inserted into the temperature difference box 800, and the conductive column 807 and the temperature difference box 800 are sealed to prevent the helium gas in the temperature difference box 800 from escaping; a cold pressing block 808 is movably connected inside the power tube 804, the outer diameter of the cold pressing block 808 is smaller than the inner diameter of the power tube 804, and a pull rod 809 is fixedly connected to the upper end of the cold pressing block 808, the upper end of the pull rod 809 slidingly passing through the top end of the power tube 804;

[0036] Two flow holes 826 are opened at the bottom of the negative pressure pipe 803. A one-way valve is installed in each of the two flow holes 826. The outlet of the liquid storage pipe 801 is connected to one of the flow holes 826, and the inlet of the cooling pipe 825 is connected to the other flow hole 826. One one-way valve allows coolant to flow into the negative pressure pipe 803 only, while the other one-way valve allows coolant to flow out of the negative pressure pipe 803 only. A negative pressure piston 812 is slidably connected inside the negative pressure pipe 803. An inner rod 815 is fixedly connected to the upper end of the negative pressure piston 812. An outer column 817 is slidably fitted around the inner rod 815. The lower end of the outer column 817 is fixedly connected to... There is a push piston 813, which is located above the negative pressure piston 812. The inner wall of the negative pressure pipe 803 is also provided with a ventilation hole, and a one-way valve is also provided in the ventilation hole. The one-way valve in the ventilation hole only allows outside air to enter the negative pressure pipe 803. The push piston 813 and the negative pressure piston 812 are both fixedly connected to the ends that are close to each other, and the two magnetic rings 814 repel each other. Several second cooling fins 806 are fixedly connected to the outer wall of the negative pressure pipe 803, and the several second cooling fins 806 are located in the upper half of the negative pressure pipe 803. The several second cooling fins 806 can further promote the cooling of the air in the negative pressure pipe 803.

[0037] Please see Figure 6 and Figure 7 The upper end of the negative pressure pipe 803 is fixedly connected to a reset pipe 816. A lower power chamber 820 is formed inside the reset pipe 816. An upper power chamber 819 is formed at the upper end of the lower power chamber 820. The inner diameter of the upper power chamber 819 is smaller than the inner diameter of the lower power chamber 820. The upper power chamber 819 and the lower power chamber 820 are connected through a guide channel 822. The outer column 817 is slidably connected inside the lower power chamber 820, and a pressure plug 82 is fixedly connected to the end of the inner rod 815 away from the negative pressure piston 812. 3. The pressure plug 823 is slidably connected in the upper power chamber 819, and a return spring 821 is fixedly connected to the top of the upper power chamber 819. Specifically, a sealing bellows 824 is sleeved on the outside of the inner rod 815. One end of the sealing bellows 824 is fixedly connected to the lower end of the pressure plug 823, and the other end is fixedly connected to the upper end of the outer column 817. The sealing bellows 824 can prevent the gas in the upper power chamber 819 and the lower power chamber 820 from flowing out through the connection between the inner rod 815 and the outer column 817.

[0038] The upper end of the pull rod 809 is fixedly connected to the pressure plug 823 via a pull rope 818. Specifically, the upper end of the negative pressure tube 803 is symmetrically fixedly connected to a fixed pulley, the pull rope 818 is laid outside the fixed pulley, and the pull rope 818 passes through the top end of the reset tube 816 and is fixedly connected to the pressure plug 823.

[0039] The working principle of this invention is:

[0040] When the voltage transformer of the present invention is in use, the temperature inside the isolation housing 2 can be detected in real time by the temperature sensor 704. When the temperature inside the isolation housing 2 rises abnormally, the staff can detect it in time and take targeted measures to avoid the voltage transformer burning out.

[0041] During operation, the voltage transformer will continuously generate heat, and the temperature inside the isolation sleeve 6 will increase significantly. When the temperature inside the isolation sleeve 6 increases, the heat conduction column 805 will transfer the temperature inside the isolation sleeve 6 to the temperature difference box 800. The helium gas in the temperature difference box 800 will transfer the temperature to the conduction column 807. When the conduction column 807 heats up, it will heat the bottom of the inside of the power tube 804. When the air below the cold pressure block 808 (the bottom of the inside of the power tube 804) is heated, the air will expand. At this time, the cold pressure block 808 will be pushed upward. As the cold pressure block 808 moves upward, the pull rod 809 will drive the pressure plug 823 to move upward in the upper power chamber 819 through the pull rope 818.

[0042] As the pressure plug 823 moves upward, it carries the negative pressure piston 812 within the negative pressure pipe 803. When the negative pressure piston 812 moves, it draws coolant from the reservoir pipe 801. As the negative pressure piston 812 moves upward, it moves closer to the pushing piston 813. As the pressure plug 823 moves upward, it compresses the air in the upper power chamber 819, causing the air in the upper power chamber 819 to flow into the lower power chamber 820 through the guide channel 822. At this time, the outer column 817 is compressed, causing the pushing piston 813 to move downward. As the pushing piston 813 and the negative pressure piston 812 approach each other, the negative pressure piston 812 is pushed downward under the action of the magnetic ring 814. When the negative pressure piston 812 is pushed downward, coolant flows into the cooling pipe 825.

[0043] As the piston 813 moves downward, the air in the negative pressure pipe 803 enters the power pipe 804 through the guide pipe 810. The air temperature in the negative pressure pipe 803 is much lower than that in the power pipe 804, so the heated air at the bottom of the power pipe 804 is cooled. At this time, the expanded air in the power pipe 804 will contract, and the air discharged through the guide pipe 810 will push the cold pressure block 808 downward. At this time, the return spring 821 will pull the pressure plug 823 to reset.

[0044] As the pressure plug 823 resets, it draws air from the lower power chamber 820 through the flow channel 822, thereby resetting the outer column 817. When the outer column 817 resets, it pushes the piston 813 to draw in outside air through the ventilation hole. This process repeats, causing the negative pressure piston 812 to work repeatedly, which in turn causes the coolant to flow in the cooling pipe 825, thereby cooling the inside of the isolation sleeve 6. When the negative pressure pipe 803 is working, coolant enters it, so the temperature inside the negative pressure pipe 803 is lower than the outside air temperature. When outside air enters the negative pressure pipe 803, it will be cooled down. This allows the invention to cool the inside of the isolation sleeve 6 without additional power, thus preventing the voltage transformer from being damaged due to excessively high internal temperature of the isolation sleeve 6.

[0045] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A dry-type voltage transformer with temperature measurement, comprising a mounting base (1), an insulating housing (2), a terminal (3) and a transformer assembly (7), characterized in that, The insulating shell (2) and the wiring terminal (3) are both fixedly connected to the upper end of the mounting base (1), and the transformer assembly (7) is connected to the wiring terminal (3) through a wire. The upper end of the mounting base (1) is also fixedly connected to the equipment compartment (5), and the upper end of the equipment compartment (5) is fixedly connected to the mounting shell (4). The inside of the mounting shell (4) is a cooling assembly (8) for cooling the inside of the insulating shell (2). The transformer assembly (7) includes several steel sheets (700) stacked together. Several inner coils (701) are wound around the outside of the steel sheets (700). An insulating layer (702) is wound around the outside of the inner coils (701). A temperature sensor (704) is inserted inside the insulating layer (702). An insulating sleeve (6) is also provided inside the insulating shell (2) to protect the transformer assembly (7). The cooling component (8) includes a temperature difference box (800), which is fixedly connected to the upper end of the equipment compartment (5), and the equipment compartment (5) is filled with helium. A plurality of heat-conducting columns (805) are fixedly connected inside the isolation sleeve (6), and the ends of the heat-conducting columns (805) away from the isolation sleeve (6) are all inserted into the temperature difference box (800). The upper end of the temperature difference box (800) is fixedly connected to a negative pressure pipe (803), and a cooling pipe (825) is connected to the outside of the negative pressure pipe (803). The end of the cooling pipe (825) away from the negative pressure pipe (803) is coiled inside the steel sheet (700). A liquid storage pipe (801) is installed on the outer wall of the isolation shell (2). The inside of the liquid storage pipe (801) is filled with coolant, and a number of first cooling fins (802) are fixedly connected to the outer wall of the liquid storage pipe (801). The outlet of the liquid storage pipe (801) is connected to the negative pressure pipe (803) through a pipe, and the return end of the cooling pipe (825) is also connected to the liquid storage pipe (801). Two power pipes (804) are symmetrically fixedly connected to the upper end of the temperature difference box (800). The power pipes (804) are located on both sides of the negative pressure pipe (803), and the two power pipes (804) are respectively connected to the negative pressure pipe (803) through the guide pipe (810). A one-way valve is installed in the guide pipe (810). The one-way valve in the guide pipe (810) only allows air in the negative pressure pipe (803) to enter the power pipe (804). A conduction column (807) is fixedly connected inside the power pipe (804). The end of the conduction column (807) away from the power pipe (804) is inserted into the temperature difference box (800). A cold pressing block (808) is movably connected inside the power pipe (804). A pull rod (809) is fixedly connected to the upper end of the cold pressing block (808). The upper end of the pull rod (809) slides through the top end of the power pipe (804).

2. A dry-type voltage transformer of which temperature is measurable according to claim 1, characterized in that, The outer side of the insulating layer (702) is also wound with several outer coils (703), and the temperature sensor (704) is located between the inner coil (701) and the outer coil (703), and the temperature sensor (704) is electrically connected to the inner coil (701).

3. A dry-type voltage transformer with temperature measurement according to claim 2, characterized in that, The steel sheet (700), inner coil (701), insulation layer (702) and outer coil (703) are all located inside the isolation sleeve (6), and the output line of the temperature sensor (704) is also electrically connected to the control motherboard inside the equipment compartment (5), and a power supply battery is also installed inside the equipment compartment (5), and insulating resin is also filled between the isolation shell (2) and the isolation sleeve (6).

4. The dry-type voltage transformer of claim 1, wherein The negative pressure tube (803) has two flow holes (826) at its bottom. A one-way valve is installed in each of the two flow holes (826). A negative pressure piston (812) is slidably connected inside the negative pressure tube (803). An inner rod (815) is fixedly connected to the upper end of the negative pressure piston (812). An outer column (817) is slidably sleeved on the outer side of the inner rod (815). A push piston (813) is fixedly connected to the lower end of the outer column (817), and the push piston (813) is located at... Above the negative pressure piston (812), an air exchange hole is also provided on the inner wall of the negative pressure pipe (803), and a one-way valve is also provided in the air exchange hole. The one-way valve in the air exchange hole only allows outside air to enter the negative pressure pipe (803). The pushing piston (813) and the negative pressure piston (812) are both fixedly connected to a magnetic ring (814) at their respective ends, and the two magnetic rings (814) repel each other. Several second cooling fins (806) are fixedly connected to the outer wall of the negative pressure pipe (803).

5. A dry-type voltage transformer of which temperature is measurable according to claim 4, characterized in that, The upper end of the negative pressure tube (803) is fixedly connected to a reset tube (816), and a lower power chamber (820) is opened in the reset tube (816). An upper power chamber (819) is opened at the upper end of the lower power chamber (820). The upper power chamber (819) and the lower power chamber (820) are connected through a guide channel (822). The outer column (817) is slidably connected in the lower power chamber (820), and a pressure plug (823) is fixedly connected to the end of the inner rod (815) away from the negative pressure piston (812).

6. A dry-type voltage transformer of which temperature is measurable according to claim 5, characterized in that, The pressure plug (823) is slidably connected in the upper power chamber (819), and a return spring (821) is fixedly connected to the top of the upper power chamber (819). The upper end of the pull rod (809) is fixedly connected to the pressure plug (823) through the pull rope (818).

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