Air leakage compensation type clean air voltage transformer

Abstract

An air leakage compensation type clean air voltage transformer belongs to the technical field of voltage transformers and comprises a transformer body, an inner cavity of a shell of the transformer body is filled with an insulating medium, the insulating medium is clean air formed by mixing oxygen and nitrogen, a pressure sensor is arranged on the shell, and the pressure sensor is connected with the transformer body. The pressure sensor is used for monitoring the pressure of clean air in the inner cavity of the shell; the shell is connected with an air supplementing system, the air supplementing system can supplement clean air into an inner cavity of the shell, the pressure sensor is electrically connected with the air supplementing system, and the pressure sensor can control the air supplementing system. The air leakage compensation type clean air voltage transformer is reasonable in design and simple in structure, has real-time monitoring and automatic compensation functions, is low in operation difficulty and high in working efficiency, can effectively save manpower and material resources, can guarantee stable operation of the voltage transformer, and is suitable for popularization.

Description

Technical Field

[0001] The invention relates to the technical field of voltage transformers, and in particular to a leakage-compensated clean air voltage transformer. Background Art

[0002] The tank voltage transformer is a gas-insulated, metal-enclosed voltage transformer. It uses the principle of electromagnetic induction to convert the voltage in the high-voltage system into a low voltage in proportion for use in measurement, protection, and automatic control devices. The working principle of the tank voltage transformer is based on the law of electromagnetic induction. Generally, there are two windings with different numbers of turns and mutual insulation on a closed iron core. The primary winding N1 is connected to the power supply side, and the secondary winding N2 is connected to the output side. Tank voltage transformers are widely used in power systems and industrial automation control fields, especially in high-voltage substations, and are often used to measure and protect transformers, switch cabinets, cables and other equipment.

[0003] Insulating gas refers to the gas medium used to isolate electrodes and prevent conduction in electrical equipment. It is mainly used in high-voltage electrical equipment and systems to prevent arc discharge and flashover and improve insulation performance. These gases can fill or surround the non-conductive parts of electrical equipment to ensure the safe operation of the equipment under high voltage. The common insulating gases on the market are mainly dry air, nitrogen, sulfur hexafluoride, etc. Insulating gas plays a vital role in electrical equipment. By selecting suitable insulating gases and taking corresponding environmental protection measures, the safe and stable operation of the power system can be ensured while reducing the negative impact on the environment.

[0004] Although the existing tank-type voltage transformer adopts a metal enclosed structure, leakage problems still occur during actual use. At present, regular manual inspections are generally used for on-site inspections. This traditional inspection method consumes a lot of manpower and material resources, has low work efficiency, and has a "gap period", making it difficult to detect leakage problems in time; at the same time, non-original gases such as nitric oxide and nitrogen dioxide will appear in the inner cavity of the voltage transformer's shell after discharge, and regular manual inspections are also difficult to detect this problem in time. Over time, the purity of the insulating gas will be reduced, affecting the stable operation of the voltage transformer. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art, such as the difficulty in detecting voltage transformers, the large amount of manpower and material resources consumed, and the low work efficiency, and to provide a leakage-compensated clean air voltage transformer with reasonable design, simple structure, real-time monitoring and automatic compensation functions, low operation difficulty, and high work efficiency. It can not only effectively save manpower and material resources, but also ensure the stable operation of the voltage transformer, and is suitable for promotion.

[0006] The present invention is realized through the following technical scheme: a leakage-compensated clean air voltage transformer, comprising a transformer body, the inner cavity of the outer shell of the transformer body is filled with an insulating medium, the insulating medium is clean air mixed with oxygen and nitrogen, the air pressure of the clean air in the inner cavity of the outer shell is not more than 0.8MPa and not less than 0.7MPa, a pressure sensor is arranged on the outer shell, and the pressure sensor is used to monitor the air pressure of the clean air in the inner cavity of the outer shell; the outer shell is connected to an air supply system, the air supply system can replenish clean air into the inner cavity of the outer shell, the pressure sensor is electrically connected to the air supply system, the pressure sensor can control the air supply system, when the air pressure of the clean air in the inner cavity of the outer shell is less than 0.7MPa, the pressure sensor controls the air supply system to replenish air, and when the air pressure is replenished to 0.8MPa, the pressure sensor controls the air supply system to stop replenishing air.

[0007] A further improvement of the present invention is that the air replenishment system includes a high-pressure oxygen cylinder, a high-pressure nitrogen cylinder and an air replenishment valve installed on the outer shell, the high-pressure oxygen cylinder is connected to an oxygen delivery pipe, the high-pressure nitrogen cylinder is connected to a nitrogen delivery pipe, the oxygen delivery pipe and the nitrogen delivery pipe are commonly connected to a mixing box, the mixing box is connected to a main delivery pipe, the main delivery pipe is connected to the air replenishment valve, the air replenishment valve is electrically connected to a pressure sensor, and the pressure sensor controls the operation of the air replenishment system by controlling the air replenishment valve.

[0008] A further improvement of the present invention is that the gas pressure of the high-pressure oxygen cylinder and the high-pressure nitrogen cylinder is greater than 1MPa, and a gas pressure controller is provided at the main delivery pipe, through which the delivery gas pressure of the main delivery pipe can be made not less than 1MPa.

[0009] A further improvement of the present invention is that a proportional regulating valve A is provided at the oxygen delivery pipe, and a proportional regulating valve B is provided at the nitrogen delivery pipe. Through the cooperation between the proportional regulating valve A and the proportional regulating valve B, the ratio of oxygen to nitrogen can be adjusted to 8:2.

[0010] A further improvement of the present invention is that the oxygen delivery pipe and the nitrogen delivery pipe are commonly connected to a mixing pipe, and the mixing pipe is connected to a mixing box; the mixing pipe includes a pipe body, and spiral blades are arranged on the inner side wall of the pipe body.

[0011] A further improvement of the present invention is that a pressure relief mechanism is provided on the outer shell, the pressure relief mechanism includes a cylinder body, one end of the cylinder body is connected to the outer shell, the other end of the cylinder body is screwed with a sealing cover, and a pressure relief hole is provided at a position of the cylinder body close to the outer shell, a piston is provided inside the cylinder body, a compression spring is provided between the side of the piston facing away from the outer shell and the inner side of the sealing cover, the two ends of the compression spring respectively abut against the piston and the sealing cover, a coaxial sealing rod is provided on the side of the piston facing the outer shell, an exhaust hole corresponding to the sealing rod is provided on the outer shell, the sealing rod is inserted in the exhaust hole, thereby forming a seal for the exhaust hole.

[0012] A further improvement of the present invention is that the pressure sensor is electrically connected to the background system of the transformer body, and the pressure sensor can transmit the air pressure information of the clean air in the inner cavity of the shell to the background system.

[0013] A further improvement of the present invention is that a gas composition detector is provided on the shell, and the gas composition detector is electrically connected to the background system of the transformer body. The gas composition detector is used to monitor the gas composition and mixing ratio of the clean air in the inner cavity of the shell, and transmit the monitoring information to the background system.

[0014] The beneficial effects of the present invention are: 1. The pressure sensor of the voltage transformer can monitor the pressure of the clean air in the inner cavity of the shell in real time, and the pressure sensor is linked with the air supply system to control the air supply system by monitoring the changes in air pressure. Through the above design, the voltage transformer has real-time monitoring and automatic compensation functions, low operation difficulty, high work efficiency, and effectively saves manpower and material resources.

[0015] 2. The pressure relief mechanism of this voltage transformer has an automatic pressure relief function. When overshoot occurs during the gas replenishment process or the transformer body causes the air pressure in the inner cavity of the shell to increase during operation, the pressure can be automatically relieved through the pressure relief mechanism, which solves the problem of increased air pressure in the inner cavity of the shell and ensures the normal operation of the voltage transformer.

[0016] 3. The pressure sensor of the voltage transformer is linked to the background system of the transformer body, and the staff can timely understand the air pressure information of the clean air in the inner cavity of the shell through the background system; and the gas composition detector of the voltage transformer is linked to the background system of the transformer body, and the staff can timely understand the composition of the clean air in the inner cavity of the shell through the background system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the description will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0018] Figure 1 It is a structural schematic diagram of a specific embodiment of the present invention.

[0019] Figure 2 It is a schematic structural diagram of a gas replenishing system according to a specific embodiment of the present invention.

[0020] Figure 3 It is a schematic diagram of the structure of a mixing pipeline according to a specific embodiment of the present invention.

[0021] Figure 4It is a structural schematic diagram of a pressure relief mechanism according to a specific embodiment of the present invention.

[0022] 1. Shell; 2. Iron core; 3. Basin insulator; 4. Protective cap; 5. Explosion-proof device; 6. Junction box; 7. Pressure sensor; 8. Air supply system; 801. High-pressure oxygen cylinder; 802. High-pressure nitrogen cylinder; 803. Air supply valve; 804. Oxygen delivery pipe; 805. Nitrogen delivery pipe; 806. Mixing pipeline; 8061. Pipeline body; 8062. Spiral blade; 807. Mixing box; 808. Main delivery pipe; 9. Pressure relief mechanism; 901. Cylinder body; 902. Sealing gland; 903. Piston; 904. Compression spring; 905. Sealing rod; 10. Gas composition detector; 11. Proportional control valve A; 12. Proportional control valve B; 13. Air pressure controller. DETAILED DESCRIPTION

[0023] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in this specific embodiment. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of them. Based on the embodiments in this patent, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this patent.

[0024] Now refer to Figure 1-4 , combined with a specific embodiment, it is explained as follows: The leakage-compensated clean air voltage transformer described in the present invention includes a transformer body, which is a tank-type voltage transformer. The transformer body is mainly composed of a shell 1, an iron core 2, a pot-type insulator 3, a protective cap 4, an explosion-proof device 5 and a junction box 6. For the specific structure, refer to the existing tank-type voltage transformer.

[0025] The inner cavity of the shell 1 of the transformer body is filled with an insulating medium, which is clean air mixed with oxygen and nitrogen. The air pressure of the clean air in the inner cavity of the shell 1 is not more than 0.8MPa and not less than 0.7MPa. A pressure sensor 7 is provided on the shell 1, and the pressure sensor 7 is used to monitor the air pressure of the clean air in the inner cavity of the shell 1; the shell 1 is connected to an air supply system 8, and the air supply system 8 can replenish clean air into the inner cavity of the shell 1. The pressure sensor 7 is electrically connected to the air supply system 8, and the pressure sensor 7 can control the air supply system 8. When the air pressure of the clean air in the inner cavity of the shell 1 is less than 0.7MPa, the pressure sensor 7 controls the air supply system 8 to replenish air. When the air pressure is equal to 0.8MPa, the pressure sensor 7 controls the air supply system 8 to stop replenishing air.

[0026] Specifically, the gas replenishment system 8 includes a high-pressure oxygen cylinder 801, a high-pressure nitrogen cylinder 802, and a gas replenishment valve 803 installed on the housing 1. The high-pressure oxygen cylinder 801 is connected to an oxygen delivery pipe 804, and the high-pressure nitrogen cylinder 802 is connected to a nitrogen delivery pipe 805. The oxygen delivery pipe 804 and the nitrogen delivery pipe 805 are connected to a mixing box 807. The mixing box 807 is connected to a main delivery pipe 808. The main delivery pipe 808 is connected to the gas replenishment valve 803. The gas replenishment valve 803 is electrically connected to the pressure sensor 7. The pressure sensor 7 controls the operation of the gas replenishment system 8 by controlling the gas replenishment valve 803. The above-mentioned high-pressure oxygen cylinder 801 and high-pressure nitrogen cylinder 802 are used as supplementary gas sources. They are mixed and temporarily stored in the mixing box 807 according to the required ratio. When replenishment is needed, they are then delivered to the inner cavity of the housing 1 through the gas replenishment valve 803.

[0027] Specifically, the gas pressure of the high-pressure oxygen cylinder 801 and the high-pressure nitrogen cylinder 802 is greater than 1MPa, and a gas pressure controller 13 is provided at the main delivery pipe 808, and the delivery gas pressure of the main delivery pipe 808 can be made not less than 1MPa through the gas pressure controller 13. The above design can ensure that the delivery gas pressure of the main delivery pipe 808 is not less than 1MPa, thereby ensuring that the gas replenishment operation proceeds smoothly.

[0028] Specifically, a ratio regulating valve A11 is provided at the oxygen delivery pipe 804, and a ratio regulating valve B12 is provided at the nitrogen delivery pipe 805. Through the cooperation between the ratio regulating valve A11 and the ratio regulating valve B12, the ratio of oxygen to nitrogen can be adjusted to 8:2. The above design can adjust the ratio of oxygen to nitrogen to 8:2, which is more reasonable, thereby ensuring the use effect of clean air.

[0029] Specifically, the oxygen delivery pipe 804 and the nitrogen delivery pipe 805 are connected to a mixing pipe 806, and the mixing pipe 806 is connected to a mixing box 807; the mixing pipe 806 includes a pipe body 8061, and a spiral blade 8062 is arranged on the inner wall of the pipe body 8061. Through the above design, during the process of oxygen and nitrogen being transported through the pipe body 8061, they are evenly mixed under the action of the spiral blade 8062, which greatly improves the mixing effect of oxygen and nitrogen and shortens the mixing time of oxygen and nitrogen.

[0030] The use principle of the present invention: combined with the existing sensor technology, the pressure sensor 7 can monitor the air pressure of the clean air in the inner cavity of the shell 1 in real time, and the pressure sensor 7 is linked with the air supply system 8 to control the air supply system 8 by monitoring the change of air pressure. That is, when there is a leak in the shell 1, when the air pressure becomes smaller and is lower than 0.7MPa, the pressure sensor 7 controls the air supply system 8 to replenish air, and when the air pressure is equal to 0.8MPa, the pressure sensor 7 controls the air supply system 8 to stop replenishing air. It can be seen that this voltage transformer has the functions of real-time monitoring of air pressure and automatic air replenishment, simple operation, high work efficiency, and great savings in manpower and material resources. It also solves the problem of "gap period" in inspection and solves the problem of air leakage in a timely manner.

[0031] In one of the embodiments, a pressure relief mechanism 9 is provided on the outer shell 1, and the pressure relief mechanism 9 includes a cylinder body 901, one end of the cylinder body 901 is connected to the outer shell 1, and the other end of the cylinder body 901 is screwed with a sealing cover 902, and a pressure relief hole is opened at a position of the cylinder body 901 close to the outer shell 1, and a piston 903 is arranged inside the cylinder body 901, and a compression spring 904 is arranged between the side of the piston 903 facing away from the outer shell 1 and the inner side of the sealing cover 902, and the two ends of the compression spring 904 respectively abut against the piston 903 and the sealing cover 902, and a coaxial sealing rod 905 is arranged on the side of the piston 903 facing the outer shell 1, and an exhaust hole corresponding to the sealing rod 905 is opened on the outer shell 1, and the sealing rod 905 is inserted in the exhaust hole to form a seal for the exhaust hole.

[0032] The above-mentioned pressure relief mechanism 9 can relieve the pressure in the inner cavity of the housing 1. The elastic force of the compression spring 904 corresponds to the air pressure of 0.8MPa. Under normal circumstances, under the action of the elastic force, the compression spring 904 always applies an elastic force to the piston 903, so that the sealing rod 905 is always inserted in the exhaust hole through the piston 903, thereby ensuring that the exhaust hole is always in a sealed state. It should be noted that the rotating sealing gland 902 can adjust the elastic force of the compression spring 904, so that the compression spring 904 can better correspond to the air pressure in the inner cavity of the housing 1; at the same time, in order to improve the sealing effect, the insertion end of the sealing rod 905 and the exhaust hole adopt a conical design, and the insertion end of the sealing rod 905 can also be made of rubber material.

[0033] When overshoot occurs during the air replenishment process or the transformer body causes the air pressure in the inner cavity of the housing 1 to rise and exceed 0.8MPa during operation, the sealing rod 905 is pushed out of the exhaust hole under the action of the air pressure. At this time, the sealing rod 905 pushes the piston 903 to compress the compression spring 904, and the exhaust hole exhausts the air at the same time, and finally exhausts the air through the pressure relief hole on the cylinder body 901. When the air pressure is about to reach 0.8MPa, the sealing rod 905 is reinserted into the exhaust hole under the action of the compression spring 904. It can be seen that the pressure relief mechanism 9 has an automatic pressure relief function, which can solve the problem of increased air pressure in the inner cavity of the housing 1.

[0034] In one embodiment, the pressure sensor 7 is electrically connected to the background system of the transformer body, and the pressure sensor 7 can transmit the air pressure information of the clean air in the inner cavity of the housing 1 to the background system. Through the above design, the staff can timely understand the air pressure information of the clean air in the inner cavity of the housing 1 through the background system.

[0035] In one embodiment, a gas composition detector 10 is provided on the housing 1, and the gas composition detector 10 is electrically connected to the background system of the transformer body. The gas composition detector 10 is used to monitor the gas composition and mixing ratio of the clean air in the inner cavity of the housing 1, and transmit the monitoring information to the background system. Combined with the instructions for use of the gas composition detector 10, the clean air in the inner cavity of the housing 1 is monitored by the gas composition detector 10. When non-original gases such as nitric oxide and nitrogen dioxide appear in the inner cavity of the housing 1, the staff can promptly discover this problem through the background system.

[0036] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referenced to each other.

[0037] The terms "upper", "lower", "outer side", "inner side", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish the relative relationship in position if they exist, and do not need to be qualitative. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0038] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A leakage-compensated clean air voltage transformer, comprising a transformer body, wherein the inner cavity of the housing (1) of the transformer body is filled with an insulating medium, and characterized in that: The insulating medium is clean air mixed with oxygen and nitrogen. The pressure of the clean air in the inner cavity of the shell (1) is not greater than 0.8 MPa and not less than 0.7 MPa. A pressure sensor (7) is provided on the shell (1). The pressure sensor (7) is used to monitor the pressure of the clean air in the inner cavity of the shell (1). The shell (1) is connected to an air supply system (8). The air supply system (8) can supply clean air to the inner cavity of the shell (1). The pressure sensor (7) is electrically connected to the air supply system (8). The pressure sensor (7) can control the air supply system (8). When the pressure of the clean air in the inner cavity of the shell (1) is less than 0.7 MPa, the pressure sensor (7) controls the air supply system (8) to supply air. When the pressure is equal to 0.8 MPa, the pressure sensor (7) controls the air supply system (8) to stop supplying air.

2. A leakage-compensated clean air voltage transformer according to claim 1, characterized in that: The gas replenishment system (8) comprises a high-pressure oxygen cylinder (801), a high-pressure nitrogen cylinder (802) and a gas replenishment valve (803) installed on the housing (1); the high-pressure oxygen cylinder (801) is connected to an oxygen delivery pipe (804); the high-pressure nitrogen cylinder (802) is connected to a nitrogen delivery pipe (805); the oxygen delivery pipe (804) and the nitrogen delivery pipe (805) are connected to a mixing box (807); the mixing box (807) is connected to a main delivery pipe (808); the main delivery pipe (808) is connected to the gas replenishment valve (803); the gas replenishment valve (803) is electrically connected to a pressure sensor (7); the pressure sensor (7) controls the gas replenishment valve (803) and thus controls the operation of the gas replenishment system (8).

3. A leakage-compensated clean air voltage transformer according to claim 2, characterized in that: The gas pressure of the high-pressure oxygen cylinder (801) and the high-pressure nitrogen cylinder (802) is greater than 1 MPa. A gas pressure controller (13) is provided at the main delivery pipe (808). The gas pressure controller (13) can ensure that the delivery gas pressure of the main delivery pipe (808) is not less than 1 MPa.

4. A leakage-compensated clean air voltage transformer according to claim 3, characterized in that: The oxygen delivery pipe (804) is provided with a ratio regulating valve A (11), and the nitrogen delivery pipe (805) is provided with a ratio regulating valve B (12). Through the cooperation between the ratio regulating valve A (11) and the ratio regulating valve B (12), the ratio of oxygen to nitrogen can be adjusted to 8:

2.

5. A leakage-compensated clean air voltage transformer according to claim 4, characterized in that: The oxygen delivery pipe (804) and the nitrogen delivery pipe (805) are connected to a mixing pipe (806), and the mixing pipe (806) is connected to a mixing box (807); the mixing pipe (806) includes a pipe body (8061), and a spiral blade (8062) is arranged on the inner side wall of the pipe body (8061).

6. A leakage-compensated clean air voltage transformer according to claim 1 or 5, characterized in that: The housing (1) is provided with a pressure relief mechanism (9), which comprises a cylinder body (901), one end of the cylinder body (901) being connected to the housing (1), the other end of the cylinder body (901) being screwed with a sealing gland (902), and a pressure relief hole being provided in the cylinder body (901) at a position close to the housing, a piston (903) being provided inside the cylinder body (901), a compression spring (904) being provided between a side of the piston (903) facing away from the housing (1) and an inner side of the sealing gland (902), two ends of the compression spring (904) respectively abutting against the piston (903) and the sealing gland (902), a coaxial sealing rod (905) being provided on a side of the piston (903) facing the housing (1), an exhaust hole corresponding to the sealing rod (905) being provided on the housing (1), and the sealing rod (905) being inserted into the exhaust hole, thereby forming a seal for the exhaust hole.

7. A leakage-compensated clean air voltage transformer according to claim 6, characterized in that: The pressure sensor (7) is electrically connected to the background system of the transformer body, and the pressure sensor (7) is capable of transmitting air pressure information of the clean air in the inner cavity of the housing (1) to the background system.

8. The leakage-compensated clean air voltage transformer according to claim 6, characterized in that: A gas composition detector (10) is provided on the housing (1). The gas composition detector (10) is electrically connected to a background system of the transformer body. The gas composition detector (10) is used to monitor the gas composition and mixing ratio of the clean air in the inner cavity of the housing (1), and transmit the monitoring information to the background system.

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