Intelligent pressurization leakage testing device for transformer

Abstract

The invention discloses an intelligent pressurization leakage testing device for a transformer, and belongs to the technical field of transformer maintenance. The device comprises a main pipeline, wherein an air compressing and pressurizing device and a gas drying tank are sequentially arranged on the main pipeline. And the gas drying tank is connected with a first electromagnetic self-control type pressure reducing valve and is connected with a second electromagnetic self-control type pressure reducing valve and a device gas outlet through a three-way pipeline. The device is further provided with three air pressure monitoring meters which are used for monitoring the air source, the pressure after primary pressure reduction and the final output pressure respectively. The digital control module is connected with all monitoring meters and execution parts, and cooperatively controls the air compressor and the two electromagnetic valves according to real-time pressure data, so that automation of pressurization, pressure maintaining and pressure relief processes is achieved, and the problems that an existing leakage testing tool is inaccurate in pressure control, depends on manual operation, is inconvenient to transport and the like are solved.

Description

Technical Field

[0001] This application relates to the field of power system transformer fault detection technology, specifically to a transformer intelligent pressure testing device. Background Technology

[0002] Oil-immersed transformers are widely used in power systems, but due to the high incidence of oil leakage, maintenance teams frequently need to perform pressure leak testing during transformer commissioning, maintenance, and troubleshooting. Existing pressure leak testing tools have the following problems: Insufficient pressure adjustment capability of the tool: The specification requires a pressure test leak pressure of 0.03 MPa, but the pressure gauge of the existing technology system is easily affected by the gas output pressure. When the output pressure is high, the pressure count value deviates significantly, affecting the process quality; when the output pressure is low, the pressurization speed is very slow, affecting work efficiency.

[0003] Transporting nitrogen cylinders is difficult and uneconomical: a 50L high-pressure nitrogen cylinder weighs about 60kg and requires multiple people to lift and transport it, resulting in poor human-machine efficiency. Moreover, high-pressure nitrogen is expensive, and the operation requires a large amount of high-pressure nitrogen, making it uneconomical.

[0004] There are safety risks associated with pressure testing tools: the current technical system requires manual observation and operation to pressurize and stop, which relies excessively on the experience and skill level of personnel. There is a risk that human error may lead to overpressure damage to the equipment or delays in power grid outages, which does not meet the requirements of the China Southern Power Grid's inherently safe enterprise construction. Summary of the Invention

[0005] The purpose of this application is to propose an intelligent transformer pressure testing device to solve the problems of insufficient pressure adjustment capability, difficulty in transporting nitrogen cylinders, and high safety risks in existing transformer pressure testing tools.

[0006] To achieve the above objectives, this application proposes an intelligent transformer pressure testing device, comprising: The main pipeline is provided with an air inlet (1), an air compression and pressurization device (2) and a gas drying tank (3) arranged sequentially along the gas flow direction. The device has an air inlet (1) for inputting gas; The first pressure monitoring gauge (4) is installed on the gas drying tank (3) to monitor the gas pressure inside the gas drying tank (3); The first electromagnetic self-controlled pressure reducing valve (5) has its inlet connected to the outlet of the gas drying tank (3). The first port of the three-way pipe (6) is connected to the outlet of the first electromagnetic self-controlled pressure reducing valve (5); The second electromagnetic self-controlled pressure reducing valve (7) is connected to the second port of the three-way pipe (6), and the outlet of the second electromagnetic self-controlled pressure reducing valve (7) is configured as the device pressure relief port (9). The device has an outlet (8) and a third port of the three-way pipe (6) for outputting gas to the transformer. The second pressure monitoring gauge (8a) is installed on the pipe near its first port on the three-way pipe and is used to monitor the gas pressure after the first stage of depressurization. The third gas pressure monitoring meter (8b) is installed on the pipe near its third port on the tee pipe to monitor the gas pressure that is finally output to the transformer; The digital control module (10) is electrically connected to the air compression and pressurization device (2), the first air pressure monitoring meter (3), the second air pressure monitoring meter (8a), the third air pressure monitoring meter (8b), the first electromagnetic self-controlled pressure reducing valve (5), and the second electromagnetic self-controlled pressure reducing valve (7). It is used to receive the pressure data from the first air pressure monitoring meter (3), the second air pressure monitoring meter (8a), and the third air pressure monitoring meter (8b), and to control the coordinated operation of the air compression and pressurization device (2), the first electromagnetic self-controlled pressure reducing valve (5), and the second electromagnetic self-controlled pressure reducing valve (7) according to the pressure data, so as to realize the automation of the pressurization, pressure holding, and pressure release process.

[0007] In some embodiments, the digital control module (10) is configured to perform the following hierarchical pressure feedback control: Based on the pressure data of the first air pressure monitoring table (3), control the start / stop or power adjustment of the air compression and pressurization device (2) to maintain the pressure inside the gas drying tank (3) within a preset air source pressure range; Based on the pressure data from the second pressure monitoring meter (8a), the opening of the first electromagnetic self-controlled pressure reducing valve (5) is controlled to precisely stabilize the gas pressure after the first stage of pressure reduction at a preset intermediate pressure target value. Based on the pressure data from the third pressure monitoring meter (8b), the opening degree of the second electromagnetic self-controlled pressure reducing valve (7) is controlled to adjust the gas pressure finally output to the transformer to the target pressure value set by the user, thereby achieving precise control of the final output pressure.

[0008] In some embodiments, the digital control module (10) is configured to execute a dynamic pressurization strategy, specifically: The pressure difference between the real-time pressure value of the third barometer (8b) and the target pressure value set by the user is continuously calculated. When the pressure difference is greater than the first threshold, the second electromagnetic self-controlled pressure reducing valve (7) is controlled to operate at the first preset opening degree to achieve rapid pressurization; When the pressure difference is less than or equal to the first threshold but greater than the second threshold, the second electromagnetic self-controlled pressure reducing valve (7) is controlled to operate at a second preset opening less than the first preset opening to achieve smooth pressurization; When the pressure difference is less than or equal to the second threshold, the second electromagnetic self-controlled pressure reducing valve (7) is controlled to close or be finely adjusted to achieve precise pressure maintenance and prevent pressure overshoot.

[0009] In some embodiments, the digital control module (10) is configured to execute pressure relief and safety protection logic, specifically: When the pressure value of the third pressure monitoring gauge (8b) exceeds the preset safety limit, the second electromagnetic self-controlled pressure reducing valve (7) is controlled to open and release pressure. During the pressure holding stage, if the pressure drop rate exceeds the preset leakage threshold based on the data from the third air pressure monitoring meter (8b), it is determined to be an abnormal leak, and the second electromagnetic self-controlled pressure reducing valve (7) is controlled to open and release pressure.

[0010] In some embodiments, the digital control module (10) is provided with a touch screen for users to set target pressurization pressure, monitor pressure data in real time, and manually control the start and stop of the device.

[0011] In some embodiments, the gas drying tank (3) is filled with a desiccant to remove moisture and impurities from the gas after it has been compressed by the air compression pressurization device (2).

[0012] Compared with the prior art, this application has the following significant advantages: Economical and efficient, easy to use: The use of an air compression pressurization device to replace the traditional high-pressure nitrogen cylinder fundamentally solves the problems of difficult transportation and high handling costs of high-pressure cylinders, and significantly reduces operating costs and manpower input.

[0013] Precise control and high process quality: By using a digital control module in conjunction with multiple air pressure monitoring gauges and electromagnetic pressure reducing valves, closed-loop precise control of the pressurization process is achieved, effectively solving the problems of large pressure deviation and insufficient adjustment capability of traditional tools, and ensuring the accuracy of leak test pressure.

[0014] Safe and reliable, reducing risks: It automates the entire process of pressurization, pressure holding and pressure release, reduces manual intervention, avoids the risk of equipment damage due to overpressure caused by human error, and meets the requirements of inherent safety.

[0015] Improved efficiency and time-saving: The automated control process responds quickly, pressurizes rapidly, and maintains stable pressure, significantly shortening the time for a single leak test and improving maintenance efficiency. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings required in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a structural diagram of a transformer intelligent pressure testing device according to an embodiment of this application. Detailed Implementation

[0018] The detailed description of the accompanying drawings is intended to illustrate the present embodiments of this application and is not intended to represent only the forms in which this application can be implemented. It should be understood that the same or equivalent functions can be accomplished by different embodiments intended to be included within the spirit and scope of this application.

[0019] like Figure 1 As shown, an embodiment of this application provides a transformer intelligent pressure testing device, comprising: The main pipeline is provided with an air inlet 1, an air compression and pressurization device 2 and a gas drying tank 3 arranged sequentially along the gas flow direction. The device has an air inlet 1 for inputting gas; The first pressure monitoring gauge 4 is installed on the gas drying tank 3 to monitor the gas pressure inside the gas drying tank 3; The first electromagnetic self-controlled pressure reducing valve 5 has its inlet connected to the outlet of the gas drying tank 3. The three-way pipe 6 has its first port connected to the outlet of the first electromagnetic self-controlled pressure reducing valve 5. The second electromagnetic self-controlled pressure reducing valve 7 is connected to the second port of the three-way pipe 6, and the outlet of the second electromagnetic self-controlled pressure reducing valve 7 is configured as the device pressure relief port 9. The device has an outlet 8, which is equipped with the third port of the three-way pipe 6 for outputting gas to the transformer; The second pressure monitoring gauge 8a is installed on the pipe near its first port on the three-way pipe and is used to monitor the gas pressure after the first stage of pressure reduction. The third gas pressure monitoring gauge 8b is installed on the pipe near its third port of the three-way pipe to monitor the gas pressure finally output to the transformer; The digital control module 10 is electrically connected to the air compression and pressurization device 2, the first pressure monitoring gauge 3, the second pressure monitoring gauge 8a, the third pressure monitoring gauge 8b, the first electromagnetic self-controlled pressure reducing valve 5, and the second electromagnetic self-controlled pressure reducing valve 7. It is used to receive pressure data from the first pressure monitoring gauge 3, the second pressure monitoring gauge 8a, and the third pressure monitoring gauge 8b, and to control the coordinated operation of the air compression and pressurization device 2, the first electromagnetic self-controlled pressure reducing valve 5, and the second electromagnetic self-controlled pressure reducing valve 7 according to the pressure data, so as to realize the automation of the pressurization, pressure holding, and pressure release processes.

[0020] Specifically, the working principle of the device in this embodiment is as follows: First, air enters through the air inlet 1, is pressurized by the air compression and pressurization device 2, and then has its moisture removed by the gas drying tank 3, forming a clean high-pressure air source. The digital control module 10, as an intelligent control unit, receives pressure data from three key nodes in real time: the first pressure monitoring gauge 4 monitors the air source pressure, the second pressure monitoring gauge 8a monitors the intermediate pressure after the first electromagnetic self-controlled pressure reducing valve 5, and the third pressure monitoring gauge 8b monitors the final output pressure to the transformer. Based on this data, the control module 10 coordinates the control of each actuator: it adjusts the air compressor 2 to stabilize the air source, precisely controls the first electromagnetic pressure reducing valve 5 to stabilize the intermediate pressure, and precisely adjusts the final output pressure to the set value by controlling the opening of the second electromagnetic pressure reducing valve 6; at the same time, when the pressure exceeds the limit or pressure relief is required, the control module 10 will instruct the second electromagnetic pressure reducing valve 6 to release pressure through the pressure relief port 7, thereby realizing the automated closed-loop control of the entire pressurization, pressure holding, and pressure relief process.

[0021] In some embodiments, the digital control module 10 is configured to perform the following hierarchical pressure feedback control: Based on the pressure data from the first air pressure monitoring meter 3, the start / stop or power adjustment of the air compression and pressurization device 2 is controlled to maintain the pressure inside the gas drying tank 3 within a preset air source pressure range. Specifically, the first level of control maintains a stable and sufficient upstream gas source pressure, providing a solid foundation for subsequent precision control. The digital control module 10 continuously monitors the reading on meter 3. When the pressure falls below the lower limit of the preset range, it starts or increases the compressor's power; when the pressure reaches the upper limit, it stops or reduces the compressor's power. Assuming the preset gas source pressure range is 0.6-0.8 MPa, when the meter 3 reading drops to 0.6 MPa, the control module starts compressor 2; when the pressure reaches 0.8 MPa, it shuts it down. This is analogous to a reservoir's water level management system, ensuring a consistently sufficient and stable water supply.

[0022] Based on the pressure data from the second pressure monitoring meter 8a, the opening of the first electromagnetic self-controlled pressure reducing valve 5 is controlled to precisely stabilize the gas pressure after the first stage of pressure reduction at a preset intermediate pressure target value. Specifically, the second-stage control reduces the unstable gas source pressure to a precise and stable "intermediate" pressure value, acting as a buffer between the initial and subsequent pressure reductions. The control module compares the readings from Table 8a with the preset intermediate pressure target value, and then dynamically and precisely adjusts the opening of the pressure reducing valve 5. Assuming the intermediate pressure target value is 0.1 MPa, if Table 8a detects a pressure of 0.09 MPa, the control module will command the opening of the pressure reducing valve 5 to increase; if it detects a pressure of 0.11 MPa, it will decrease the opening, thus precisely "pinning" the pressure after the first-stage pressure reduction to 0.1 MPa.

[0023] Based on the pressure data from the third pressure monitoring meter 8b, the opening degree of the second electromagnetic self-controlled pressure reducing valve 7 is controlled to adjust the gas pressure finally output to the transformer to the target pressure value set by the user, thereby achieving precise control of the final output pressure.

[0024] Specifically, the third-level control aims to achieve the most precise adjustment of the final output pressure to the transformer based on a stable intermediate pressure, directly meeting the leak test process requirements. The control module performs millisecond-level fine-tuning of the pressure reducing valve 6 based on the difference between the real-time reading in Table 8b and the user-set target pressure value, such as 0.03 MPa. The user-set target pressure is 0.03 MPa. The control module uses the readings in Table 8b to precisely control the pressure reducing valve 6, adjusting for any pressure difference and closing it slightly if the pressure is too high. If the pressure is 0.029 MPa, the valve is slightly opened; if it is 0.031 MPa, the valve is slightly closed, ensuring that the final pressure applied to the transformer is exactly as expected.

[0025] In summary, to achieve intelligent and high-precision control, this embodiment proposes a "hierarchical pressure feedback control" strategy. This strategy cleverly decomposes the complex task of "pressurizing from 0 to a precise target value" into three relatively simple and independent sub-tasks. Each sub-task is completed by an independent "sensor-controller-actuator" loop. The greatest advantage of this hierarchical control lies in decoupling and isolating disturbances. For example, the start-up and shutdown of the first-stage compressor 2 will cause fluctuations in the gas source pressure. However, due to the existence of the second-stage control loop, these fluctuations are quickly absorbed and regulated by the pressure reducing valve 5, and are not directly transmitted to the final output. This ensures the stability and high precision of the third-stage control. This is similar to a multi-stage shock absorption system, where each stage absorbs a portion of the impact, ultimately achieving an extremely stable effect.

[0026] In some embodiments, the digital control module 10 is configured to execute a dynamic pressurization strategy, specifically: The pressure difference between the real-time pressure value of the third barometer 8b and the target pressure value set by the user is continuously calculated. Specifically, the initial real-time pressure value is lower than the target pressure value, and the pressure needs to be increased gradually; First, when the pressure difference is greater than the first threshold, the second electromagnetic self-controlled pressure reducing valve 7 is controlled to operate at the first preset opening degree to achieve rapid pressurization; Then, when the pressure difference is less than or equal to the first threshold but greater than the second threshold, the second electromagnetic self-controlled pressure reducing valve 7 is controlled to operate at a second preset opening less than the first preset opening to achieve smooth pressurization. Finally, when the pressure difference is less than or equal to the second threshold, the second electromagnetic self-regulating pressure reducing valve 7 is controlled to close or be finely adjusted to achieve precise pressure maintenance and prevent pressure overshoot.

[0027] Specifically, the dynamic pressurization strategy in this embodiment is an intelligent segmented control method. It calculates the difference between the current pressure and the target pressure in real time and divides the pressurization process into three stages based on a preset threshold: when moving away from the target, it uses a large opening to achieve rapid pressurization; when approaching the target, it switches to a smaller opening for gradual pressurization; and when about to reach the target, it achieves precise pressure maintenance by closing or fine-tuning the valve, effectively preventing pressure overshoot, thus cleverly solving the contradiction between pressurization speed and control accuracy.

[0028] In some embodiments, the digital control module 10 is configured to execute pressure relief and safety protection logic, specifically: When the pressure value of the third pressure monitoring gauge 8b exceeds the preset safety limit, the second electromagnetic self-controlled pressure reducing valve 7 is controlled to open and release pressure. During the pressure holding phase, if the pressure drop rate exceeds the preset leakage threshold based on the data from the third air pressure monitoring table 8b, it is determined to be an abnormal leak, and the second electromagnetic self-controlled pressure reducing valve 7 is controlled to open and release pressure.

[0029] Specifically, the pressure relief and safety protection logic in this embodiment ensures operational safety through two complementary mechanisms. First, it provides passive overpressure protection: when the final output pressure exceeds the preset safety upper limit as monitored by the third pressure monitoring gauge 8b, the control module immediately commands the second electromagnetic pressure reducing valve 6 to open and relieve pressure to prevent equipment damage. Furthermore, it performs active anomaly diagnosis: during the pressure holding phase, if the system detects that the pressure drop rate is too rapid, exceeding the preset leakage threshold, it identifies this as a serious leak in the test object and actively opens valve 6 to relieve pressure, thereby avoiding invalid pressure holding attempts and improving test efficiency and safety. In some embodiments, the digital control module 10 is equipped with a touchscreen for users to set the target pressurization pressure, monitor pressure data in real time, and manually control the start and stop of the device.

[0030] Specifically, the touchscreen integrated into the digital control module 10 serves as the core interface for user interaction with the device, greatly enhancing the intuitiveness and convenience of operation. Users can easily set the target pressurization pressure through this touchscreen and intuitively monitor pressure data at key points in real-time charts or numerical values, making the entire pressurization process transparent and controllable. Simultaneously, it also provides manual control of the device's start and stop functions, ensuring that operators can still make necessary manual interventions based on site conditions outside of automatic mode, thereby enhancing the device's ease of use and operational flexibility.

[0031] In some embodiments, the gas drying tank 3 is filled with a desiccant to remove moisture and impurities from the gas after it has been compressed by the air compression and pressurization device 2.

[0032] Specifically, the desiccant inside the gas drying canister 3 plays a crucial role as a gas purifier. Because air inevitably releases moisture and carries impurities after being compressed by the air compression and pressurization device 2, these contaminants, if directly introduced into the transformer, would severely damage its internal insulation performance and affect the accuracy of leak test results. Therefore, this drying canister effectively removes moisture and impurities from the gas through the adsorption effect of the desiccant, ensuring the cleanliness and dryness of the output gas, thereby protecting the tested equipment and guaranteeing the reliability of the test.

[0033] The process of the intelligent transformer pressure testing device for testing transformers is a highly automated and intelligent closed-loop control process, which can be summarized into the following four main stages: Phase 1: Preparation and Setup; Physical connection: The operator connects the device's air outlet 8 to the air inlet of the transformer's oil tank bladder or other components that require pressure testing via a dedicated air pipe and connector.

[0034] Parameter setting: The operator sets the key parameters for this leak test operation through the touch screen of the digital control module 10. The most important parameters are the target pressurization pressure, such as the standard 0.03MPa, and the pressure holding time, such as 30 minutes.

[0035] Start the test: After the parameters are set, the operator clicks the "Start Test" button on the touch screen.

[0036] Phase Two: Intelligent Pressurization; Start the air source: After receiving the start command, the digital control module 10 first starts the air compression and pressurization device 2 to start working, compressing the air and sending it into the gas drying tank 3.

[0037] Graded stability: The control module 10 controls the start / stop or power of the compressor 2 based on the data from the first air pressure monitoring table 4, ensuring that the air source pressure is stable within a preset range, such as 0.6-0.8 MPa.

[0038] Meanwhile, the control module 10 precisely adjusts the opening of the first electromagnetic self-regulating pressure reducing valve 5 based on the data from the second air pressure monitoring meter 8a, stabilizing the pressure at an intermediate value such as 0.1MPa, thus laying the foundation for final precise control.

[0039] Dynamic pressurization: This is the core of pressurization. Control module 10 focuses on the data from the third barometer 8b and executes the dynamic pressurization strategy: Rapid pressurization: In the initial stage, the pressure difference is large, and the module controls the second electromagnetic self-controlled pressure reducing valve 7 to operate at a large opening, and gas is rapidly filled into the transformer capsule.

[0040] Gradual pressurization: When the pressure approaches the target value, the module reduces the opening of valve 6 to slow down the pressurization rate.

[0041] Precise positioning: When the pressure is very close to the target value, the module fine-tunes or briefly closes valve 6 to ensure that the pressure reaches 0.03MPa precisely without overshooting.

[0042] Phase Three: Pressure Holding and Leak Testing; Entering the pressure holding phase: Once the third pressure monitoring gauge 8b confirms that the pressure has reached the target value, the system automatically enters the "pressure holding" phase and begins the countdown.

[0043] Leakage monitoring: During the pressure holding period, the digital control module 10 continuously and frequently reads the readings of the third pressure monitoring gauge 8b and analyzes the pressure change trend.

[0044] Normal situation: If the pressure remains stable or the rate of decrease is very small and within the allowable range, it indicates that the seal is good.

[0045] Abnormal Leakage: If the module detects that the rate of pressure drop exceeds the preset "leakage threshold", it will determine it as an "abnormal leak" and can issue an alarm.

[0046] Phase Four: Termination and Depressurization; Test End: The test process will automatically end when the set pressure holding time ends or when an abnormal leak is detected.

[0047] Automatic pressure relief: To ensure safety, the digital control module 10 will issue a command to fully open the second electromagnetic self-controlled pressure reducing valve 7 to the pressure relief function, and the compressed air in the system will be safely released into the atmosphere through the device's pressure relief port 9.

[0048] Results presentation: After depressurization is complete, the touchscreen will display the test results, such as "Test completed, sealing qualified" or "Leak detected", and can provide a report containing pressure-time curves for operators to record and analyze.

[0049] Through the above four stages, the device in this embodiment completely replaces manual observation and operation, realizing full automation of the pressure leak test operation. The whole process is fast, accurate, and extremely safe.

[0050] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used in these embodiments is chosen to best explain the principles, practical applications, or technological improvements to the embodiments in the market, or to enable other those skilled in the art to understand the embodiments disclosed herein.

Claims

1. A transformer intelligent pressure testing device, characterized in that, include: The main pipeline is provided with an air inlet (1), an air compression and pressurization device (2) and a gas drying tank (3) arranged sequentially along the gas flow direction. The device has an air inlet (1) for inputting gas; The first pressure monitoring gauge (4) is installed on the gas drying tank (3) to monitor the gas pressure inside the gas drying tank (3); The first electromagnetic self-controlled pressure reducing valve (5) has its inlet connected to the outlet of the gas drying tank (3). The first port of the three-way pipe (6) is connected to the outlet of the first electromagnetic self-controlled pressure reducing valve (5); The second electromagnetic self-controlled pressure reducing valve (7) is connected to the second port of the three-way pipe (6), and the outlet of the second electromagnetic self-controlled pressure reducing valve (7) is configured as the device pressure relief port (9). The device has an outlet (8) and a third port of the three-way pipe (6) for outputting gas to the transformer. The second pressure monitoring gauge (8a) is installed on the pipe near its first port on the three-way pipe and is used to monitor the gas pressure after the first stage of depressurization. The third gas pressure monitoring meter (8b) is installed on the pipe near its third port on the tee pipe to monitor the gas pressure that is finally output to the transformer; The digital control module (10) is electrically connected to the air compression and pressurization device (2), the first air pressure monitoring meter (3), the second air pressure monitoring meter (8a), the third air pressure monitoring meter (8b), the first electromagnetic self-controlled pressure reducing valve (5), and the second electromagnetic self-controlled pressure reducing valve (7). It is used to receive the pressure data from the first air pressure monitoring meter (3), the second air pressure monitoring meter (8a), and the third air pressure monitoring meter (8b), and to control the coordinated operation of the air compression and pressurization device (2), the first electromagnetic self-controlled pressure reducing valve (5), and the second electromagnetic self-controlled pressure reducing valve (7) according to the pressure data, so as to realize the automation of the pressurization, pressure holding, and pressure release process.

2. The intelligent transformer pressure testing device as described in claim 1, characterized in that, The digital control module (10) is configured to perform the following hierarchical pressure feedback control: Based on the pressure data of the first air pressure monitoring table (3), control the start / stop or power adjustment of the air compression and pressurization device (2) to maintain the pressure inside the gas drying tank (3) within a preset air source pressure range; Based on the pressure data from the second pressure monitoring meter (8a), the opening of the first electromagnetic self-controlled pressure reducing valve (5) is controlled to precisely stabilize the gas pressure after the first stage of pressure reduction at a preset intermediate pressure target value. Based on the pressure data from the third pressure monitoring meter (8b), the opening degree of the second electromagnetic self-controlled pressure reducing valve (7) is controlled to adjust the gas pressure finally output to the transformer to the target pressure value set by the user, thereby achieving precise control of the final output pressure.

3. The intelligent transformer pressure testing device as described in claim 2, characterized in that, The digital control module (10) is configured to execute a dynamic pressurization strategy, specifically: The pressure difference between the real-time pressure value of the third barometer (8b) and the target pressure value set by the user is continuously calculated. When the pressure difference is greater than the first threshold, the second electromagnetic self-controlled pressure reducing valve (7) is controlled to operate at the first preset opening degree to achieve rapid pressurization; When the pressure difference is less than or equal to the first threshold but greater than the second threshold, the second electromagnetic self-controlled pressure reducing valve (7) is controlled to operate at a second preset opening less than the first preset opening to achieve smooth pressurization; When the pressure difference is less than or equal to the second threshold, the second electromagnetic self-controlled pressure reducing valve (7) is controlled to close or be finely adjusted to achieve precise pressure maintenance and prevent pressure overshoot.

4. The intelligent transformer pressure testing device as described in claim 2, characterized in that, The digital control module (10) is configured to execute pressure relief and safety protection logic, specifically: When the pressure value of the third pressure monitoring gauge (8b) exceeds the preset safety limit, the second electromagnetic self-controlled pressure reducing valve (7) is controlled to open and release pressure. During the pressure holding stage, if the pressure drop rate exceeds the preset leakage threshold based on the data from the third air pressure monitoring meter (8b), it is determined to be an abnormal leak, and the second electromagnetic self-controlled pressure reducing valve (7) is controlled to open and release pressure.

5. The intelligent transformer pressure testing device as described in any one of claims 1 to 4, characterized in that, The digital control module (10) is equipped with a touch screen for users to set target pressurization pressure, monitor pressure data in real time, and manually control the start and stop of the device.

6. The intelligent transformer pressure testing device as described in any one of claims 1 to 4, characterized in that, The gas drying tank (3) is filled with a desiccant to remove moisture and impurities from the gas after it has been compressed by the air compression pressurization device (2).

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