Intelligent control system of transformer vacuum oil filter

Abstract

The application relates to the technical field of transformer maintenance equipment, in particular to a transformer vacuum oil filter intelligent control system. The system comprises a pressure monitoring module, an alarm module, a pressure relief module, a video monitoring module, a control module and a man-machine interaction module. The pressure monitoring module adopts double pressure sensors to monitor the system pressure in real time; the alarm module is configured with a hierarchical delay trigger mechanism, a first alarm signal is triggered when the pressure exceeds a first threshold value and lasts for a first delay time, and a second alarm signal is triggered when the pressure exceeds a second threshold value and lasts for a second delay time; the pressure relief module is automatically opened when the pressure exceeds the second threshold value, and is automatically closed or waits for manual reset according to the reset mode selected by a user; the video monitoring module collects oil state images; the control module automatically controls the video monitoring module to capture and store the images in association with the alarm event when the alarm is triggered; and the man-machine interaction module displays alarm information and real-time video and receives manual confirmation input.

Description

Technical Field

[0001] This application relates to the field of transformer maintenance equipment technology, and more specifically, to an intelligent control system for a transformer vacuum oil filter. Background Technology

[0002] As a core piece of equipment for insulating oil treatment in power systems, transformer vacuum oil filters play an irreplaceable role in transformer installation, inspection, and daily maintenance. Their performance directly affects the insulation strength, service life, and power grid safety of transformers. my country has a large number of transformers in operation, and oil filtration operations are frequent. However, there are long-standing problems such as low equipment intelligence, crude pressure control, and difficulty in tracing abnormal events, resulting in low oil filtration efficiency, frequent equipment failures, and even safety accidents such as oil leaks and pipe bursts caused by excessive pressure. Traditional vacuum oil filters mainly rely on mechanical pressure switches and simple relays for control. When the filter element is clogged or the oil outlet valve is accidentally closed, the system pressure rises sharply. The conventional approach is to set a single pressure threshold to trigger an alarm or shutdown. This method is prone to frequent malfunctions due to instantaneous pressure fluctuations, and manual reset is often required on-site after pressure relief, leading to long-term shutdowns in unattended scenarios.

[0003] In recent years, PLC control technology has been gradually introduced into oil filtration systems, enabling overpressure protection and audible and visual alarms. However, these solutions still employ fixed thresholds and alarm logic without time-delay differentiation, failing to distinguish between instantaneous disturbances and sustained overpressure. Pressure relief valve control is often limited to simple solenoid valves that open and close directly, lacking refined management based on pressure grading and reset mode selection. Furthermore, existing oil filtration systems generally lack intuitive recording methods for overpressure events. Operators can only rely on post-event pressure curve analysis to determine the cause, making it difficult to quickly pinpoint whether the issue is filter blockage, valve malfunction, or sensor failure. Regarding visualization, while some equipment features observation windows in the enclosure, these are often made of acrylic glass, which is prone to deformation and fogging under high temperature and vacuum conditions, and is not integrated with the control system. Remote video monitoring is only an optional feature in a few high-end devices, lacking intelligent functions such as automatic alarm-triggered video recording and image recognition of oil level bubbles.

[0004] Therefore, there is an urgent need for an intelligent control system for transformer vacuum oil filters that can achieve graded delayed alarms, selectable pressure relief and reset modes, and video event linkage and tracing, in order to improve the reliability and intelligence of pressure control and reduce false alarm rate and accident risk. Summary of the Invention

[0005] In view of this, in order to solve the above-mentioned problems in the prior art, this application provides an intelligent control system for a transformer vacuum oil purifier.

[0006] The embodiments of this application are implemented as follows: This application provides an intelligent control system for a transformer vacuum oil filtration machine, including a pressure monitoring module, an alarm module, a pressure relief module, a video monitoring module, a control module, and a human-machine interaction module. The pressure monitoring module includes a first pressure sensor and a second pressure sensor. Both the first pressure sensor and the second pressure sensor are installed in the oil circuit of the oil filter to monitor the system pressure in real time. The signal output terminal of the pressure monitoring module is connected to the alarm module and the control module, respectively. The input terminal of the alarm module is connected to the signal output terminal of the pressure monitoring module. When the system pressure exceeds a first threshold and the duration exceeds a first delay time, a first alarm signal is triggered. When the system pressure exceeds a second threshold and the duration exceeds a second delay time, a second alarm signal is triggered. The second threshold is greater than the first threshold, and the second delay time is less than the first delay time. The alarm signal output terminal of the alarm module is connected to the human-machine interaction module and the control module. The pressure relief module is installed on the pressure relief pipeline of the oil filter. The control terminal of the pressure relief module is connected to the output terminal of the control module. When the system pressure exceeds the second threshold, the pressure relief module is opened. After pressure relief, the pressure relief module is automatically closed or waits for a manual reset signal according to the reset mode selected by the user. The video monitoring module is installed at the observation window and is used to collect images of the oil condition. The data output terminal of the video monitoring module is connected to the data input terminal of the control module. The first signal input terminal of the control module is connected to the alarm signal output terminal of the alarm module, the second signal input terminal of the control module is connected to the signal output terminal of the pressure monitoring module, and the data input terminal of the control module is connected to the data output terminal of the video monitoring module. When the first alarm signal or the second alarm signal is received, the video monitoring module is automatically controlled to capture an image and associate the image with the alarm event for storage. The human-machine interface module is bidirectionally connected to the control module and is used to display alarm information, real-time video footage, and receive manual confirmation input. When the second alarm signal is triggered, the control module needs to receive the manual confirmation input from the human-machine interface module before controlling the pressure relief module to reset or the system to resume operation.

[0007] In one possible implementation, the alarm module further includes an adaptive delay adjustment unit. The input of the adaptive delay adjustment unit is connected to the operating mode signal output of the control module. The adaptive delay adjustment unit automatically adjusts the first delay time and the second delay time according to the current operating mode of the oil filter. The operating mode includes filtration mode, regeneration mode, and shutdown cooling mode.

[0008] In one possible implementation, the pressure relief module includes a pilot-operated solenoid pressure relief valve and a manual ball valve connected in series with the pilot-operated solenoid pressure relief valve. The reset modes include automatic recovery mode and manual reset mode; Automatic recovery mode: When the system pressure drops below the recovery threshold after depressurization and the duration exceeds the recovery delay time, the control module controls the pilot-operated electromagnetic pressure relief valve to automatically close. Manual reset mode: The pilot-operated solenoid pressure relief valve remains open until the human-machine interface module receives a manual reset command, at which point the control module controls the pilot-operated solenoid pressure relief valve to close.

[0009] In one possible implementation, the pressure monitoring module further includes a pressure change rate detection unit. The input of the pressure change rate detection unit is connected to the output of the first pressure sensor and the second pressure sensor, and the output of the pressure change rate detection unit is connected to the alarm module and the control module. When the change in system pressure within a unit time exceeds the change rate threshold, the alarm module and the pressure relief module are prohibited from triggering.

[0010] In one possible implementation, the observation window includes tempered glass, and an LED light and an electric heating film are integrated on the window frame. The control terminals of the LED light and the electric heating film are respectively connected to the output terminal of the control module. The electric heating film automatically starts defogging based on the difference between the temperature inside the window and the dew point temperature.

[0011] In one possible implementation, the video monitoring module includes a first camera and a second camera. The first camera is installed facing the observation window to capture the overall state of the oil, and the second camera is installed on the top of the oil filter housing to capture the surface of the oil. The video monitoring module supports multi-view switching, manual snapshot, and storage functions.

[0012] In one possible implementation, an image analysis module is also included, wherein the input of the image analysis module is connected to the data output of the video surveillance module, and the output of the image analysis module is connected to the input of the control module.

[0013] In one possible implementation, a safety redundancy module is also included. The safety redundancy module includes a mechanical pressure switch installed in the oil circuit of the oil filter. The normally closed contact of the mechanical pressure switch is connected in series in the power circuit of the oil filter heater and the oil pump. When the system pressure exceeds the mechanical safety threshold, the normally closed contact of the mechanical pressure switch opens, directly cutting off the power supply to the heater and the oil pump.

[0014] In one possible implementation, the human-machine interaction module is an industrial touch screen. The manual confirmation input includes clicking a confirmation button on the screen, entering an employee number, and fingerprint recognition. Before receiving the manual confirmation input, even if the system pressure returns to normal, the control module maintains the shutdown interlock state corresponding to the second alarm signal.

[0015] In one possible implementation, the first threshold is 0.5 MPa, the second threshold is 0.7 MPa, the first delay time is 3 to 10 seconds, and the second delay time is 1 to 3 seconds.

[0016] The technical solution provided in this application can achieve at least the following beneficial effects: This application provides an intelligent control system for a transformer vacuum oil purifier. The system uses a pressure monitoring module to collect real-time data from dual pressure sensors and transmits the system pressure value to an alarm module and a control module. The alarm module employs a tiered delay triggering mechanism to eliminate instantaneous pressure fluctuations and interference spikes, preventing frequent false alarms. It also distinguishes between alert alarms and critical alarms, improving alarm accuracy and system reliability. Furthermore, the pressure relief module automatically opens a pilot-operated electromagnetic pressure relief valve when the pressure exceeds a second threshold, supporting both automatic recovery and manual reset modes. Combined with a series-connected manual ball valve, it achieves maintenance isolation, meeting the safety and efficiency requirements of different monitoring scenarios.

[0017] Furthermore, the pressure change rate detection unit further eliminates sensor spike interference to prevent false triggering; the control module automatically links with the video monitoring module to capture and record images when an alarm event is triggered, storing the images in association with the alarm event for fault traceability; the observation window integrates tempered glass, LED lighting, and an electric heating film to ensure clear images in high humidity and cold environments; dual cameras and multi-view switching, along with manual capture functions, comprehensively record the oil status; the image analysis module identifies oil level, bubble density, and color change trends, providing non-contact auxiliary monitoring; the normally closed contact of the mechanical pressure switch in the safety redundancy module is connected in series with the heater and oil pump power circuits to achieve hard-lock emergency shutdown in case of electronic control failure; the human-machine interface module displays alarm information and real-time video, and receives manual confirmation input to ensure timely handling of serious alarms; finally, the adaptive delay adjustment unit automatically adjusts the delay parameters according to the filtering mode, regeneration mode, and shutdown cooling mode to optimize the control strategy under different operating conditions.

[0018] This system significantly improves the intelligence and safety of pressure control in vacuum oil filters by employing multiple mechanisms, including graded delayed alarms, dual sensor redundancy, pressure change rate-based anti-malfunction, video linkage tracing, intelligent observation window, image analysis, and mechanical safety redundancy. It also reduces false alarm rates and accident risks, enhances fault analysis and handling efficiency, and enables reliable operation in unattended scenarios. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the system module framework of an intelligent control system for a transformer vacuum oil purifier, as shown in an exemplary embodiment of this application. Figure 2 This is a schematic diagram of the oil circuit structure shown in an exemplary embodiment of this application; Figure 3 This is a schematic diagram of the structure of the viewing window shown in an exemplary embodiment of this application.

[0021] Figure label: 100. Intelligent control system for transformer vacuum oil purifier; 110. Pressure monitoring module; 111. First pressure sensor; 112. Second pressure sensor; 113. Pressure change rate detection unit; 120. Alarm module; 121. Adaptive delay adjustment unit; 130. Pressure relief module; 131. Pilot-operated solenoid pressure relief valve; 132. Manual ball valve; 140. Video monitoring module; 141. First camera; 142. Second camera; 150. Control module; 151. Programmable logic controller; 160. 161. Human-machine interaction module; 162. Industrial touch screen; 163. Fingerprint module; 170. Log; 180. Image analysis module; 181. Safety redundancy module; 181. Mechanical pressure switch; 210. Observation window; 211. Tempered glass; 212. Window frame; 213. LED lighting; 214. Electric heating film; 215. Temperature and humidity sensor; 216. Sealing ring; 217. Pressure plate; 301. Oil pump; 302. Fine filter; 303. Main pipeline; 304. Oil storage tank; 310. Pressure relief pipeline. Detailed Implementation

[0022] To make the objectives, implementation methods and advantages of this application clearer, the exemplary implementation methods of this application will be clearly and completely described below with reference to the accompanying drawings of the exemplary embodiments of this application. Obviously, the exemplary embodiments described are only some embodiments of this application, and not all embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0023] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0024] The terms "first," "second," "third," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar or related objects or entities, and do not necessarily imply a specific order or sequence, unless otherwise specified. It should be understood that such terms are interchangeable where appropriate.

[0025] The terms “comprising” and “having”, and any variations thereof, are intended to cover but not exclude inclusion, for example, a product or device that includes a range of components is not necessarily limited to all of the components that are clearly listed, but may include other components that are not clearly listed or that are inherent to such product or device.

[0026] Next, the technical solutions of this application and how they solve the aforementioned technical problems will be described in detail through embodiments and in conjunction with the accompanying drawings. The embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application.

[0027] In one exemplary embodiment, such as Figure 1 As shown, an intelligent control system 100 for a transformer vacuum oil purifier is provided. In this embodiment, the system may include a pressure monitoring module 110, an alarm module 120, a pressure relief module 130, a video monitoring module 140, a control module 150, and a human-machine interaction module 160. The pressure monitoring module 110 includes a first pressure sensor 111 and a second pressure sensor 112. The first pressure sensor 111 and the second pressure sensor 112 are both installed in the oil circuit of the oil filter and are used to monitor the system pressure in real time. The signal output terminal of the pressure monitoring module 110 is connected to the alarm module 120 and the control module 150 respectively. The input terminal of the alarm module 120 is connected to the signal output terminal of the pressure monitoring module 110. When the system pressure exceeds a first threshold and the duration exceeds a first delay time, a first alarm signal is triggered. When the system pressure exceeds a second threshold and the duration exceeds a second delay time, a second alarm signal is triggered. The second threshold is greater than the first threshold, and the second delay time is less than the first delay time. The alarm signal output terminal of the alarm module 120 is connected to the human-machine interaction module 160 and the control module 150. The pressure relief module 130 is installed on the pressure relief pipeline 310 of the oil filter. The control terminal of the pressure relief module 130 is connected to the output terminal of the control module 150. When the system pressure exceeds the second threshold, the pressure relief module 130 is opened. After pressure relief, the pressure relief module 130 is automatically closed according to the reset mode selected by the user or waits for a manual reset signal. The video monitoring module 140 is installed at the observation window 210 and is used to collect images of the oil status. The data output terminal of the video monitoring module 140 is connected to the data input terminal of the control module 150. The first signal input terminal of the control module 150 is connected to the alarm signal output terminal of the alarm module 120, the second signal input terminal of the control module 150 is connected to the signal output terminal of the pressure monitoring module 110, and the data input terminal of the control module 150 is connected to the data output terminal of the video monitoring module 140. When the first alarm signal or the second alarm signal is received, the video monitoring module 140 is automatically controlled to capture an image and associate the image with the alarm event for storage. The human-machine interaction module 160 is bidirectionally connected to the control module 150 and is used to display alarm information and real-time video footage, and to receive manual confirmation input. When the second alarm signal is triggered, the control module 150 needs to receive the manual confirmation input from the human-machine interaction module 160 before controlling the pressure relief module 130 to reset or the system to resume operation.

[0028] In one embodiment, such as Figure 1 and Figure 2As shown, the intelligent control system 100 for the transformer vacuum oil filtration machine includes a pressure monitoring module 110, an alarm module 120, a pressure relief module 130, a video monitoring module 140, a control module 150, and a human-machine interaction module 160. The modules are connected and exchange data through signal lines, data buses, or industrial fieldbuses. The control module 150 uses a combination of a programmable logic controller 151 and an industrial-grade embedded industrial control computer. The PLC is responsible for real-time logic control and signal acquisition, while the industrial control computer is responsible for image processing, data storage, and the operation of the human-machine interface. This system can be applied to vacuum oil filtration equipment for various transformer oils and insulating oils, and is especially suitable for occasions requiring unattended operation or remote monitoring.

[0029] The pressure monitoring module 110 includes a first pressure sensor 111 and a second pressure sensor 112. Both the first pressure sensor 111 and the second pressure sensor 112 are installed in the oil circuit of the oil filter. Specifically, they can be installed at the outlet of the oil pump 301 and the front end of the fine filter 302, respectively. The two sensors are pressure transmitters with a range of 0 to 1.0 MPa and an accuracy of 0.5 class. The two sensors are powered independently and output 4 to 20 mA analog signals. The signal output terminal of the pressure monitoring module 110 is connected to the analog input terminal of the alarm module 120 and the analog input terminal of the control module 150, respectively. The two sensors work simultaneously. The control module 150 reads the two pressure values ​​in real time and performs mutual verification: if the difference between the two exceeds 0.05 MPa for more than 5 seconds, it is judged as a sensor fault and a sensor fault alarm is issued.

[0030] The input terminal of the alarm module 120 is connected to the signal output terminal of the pressure monitoring module 110. When the system pressure exceeds the first threshold and the duration exceeds the first delay time, a first alarm signal (indicative alarm) is triggered; when the system pressure exceeds the second threshold and the duration exceeds the second delay time, a second alarm signal (critical alarm) is triggered. The second threshold is greater than the first threshold, and the second delay time is less than the first delay time. Example parameters: first threshold 0.5MPa, first delay time 8 seconds; second threshold 0.7MPa, second delay time 0.5 seconds. The alarm signal output terminal of the alarm module 120 is connected to the human-machine interaction module 160 and the control module 150, respectively.

[0031] The pressure relief module 130 is installed on the pressure relief pipeline 310 of the oil filter. One end of the pressure relief pipeline 310 is connected to the main pipeline 303 between the oil pump 301 and the fine filter 302, and the other end is connected to the return oil tank or storage tank 304. The control terminal of the pressure relief module 130 is connected to the output terminal of the control module 150. When the control module 150 determines that the system pressure exceeds the second threshold (0.7MPa), it controls the pressure relief module 130 to open, and the oil flows back to the oil tank through the pressure relief pipeline 310. After pressure relief, the oil is returned to the tank according to the user's pre-selected parameters on the human-machine interface module 160. The pressure relief module 130 will automatically shut down or wait for a manual reset signal if the selected reset mode (automatic recovery mode or manual reset mode) is selected. Specifically, if the automatic recovery mode is selected, the control module 150 will output a shut-off signal after the pressure drops to the recovery threshold (e.g., 0.45 MPa) and the duration exceeds the recovery delay (e.g., 5 seconds). If the manual reset mode is selected, the pressure relief module 130 will remain open until the operator clicks the "Reset" button on the human-machine interface module 160 and enters the confirmation information, at which point the control module 150 will shut down the pressure relief module 130.

[0032] The video monitoring module 140 is installed at the observation window 210 to collect images of the oil status. In this embodiment, a high-definition network camera is used and installed facing the observation window 210. The camera is connected to the industrial control computer via Ethernet. The data output terminal of the video monitoring module 140 is connected to the data input terminal of the control module 150. The control module 150 can display the video in real time and capture and record images when needed.

[0033] The first signal input terminal of the control module 150 is connected to the alarm signal output terminal of the alarm module 120, the second signal input terminal is connected to the signal output terminal of the pressure monitoring module 110, and the data input terminal is connected to the data output terminal of the video monitoring module 140. When the first alarm signal or the second alarm signal is received, the video monitoring module 140 is automatically controlled to capture images and associate the captured images with the alarm events and store them in the local database of the industrial control computer or the solid-state drive. For the second alarm signal, in addition to capturing images, continuous recording can also be automatically started for detailed analysis of the cause of overpressure.

[0034] The human-machine interface module 160 and the control module 150 are bidirectionally connected. In this embodiment, a 10-inch industrial touch screen 161 is used. The human-machine interface module 160 is used to display alarm information (pop-up window, color flashing), real-time video footage (video stream pushed by the industrial control computer), and receive manual confirmation input. When the second alarm signal is triggered, the control module 150 must receive manual confirmation input from the human-machine interface module 160 before allowing the pressure relief module 130 to reset or the system to resume operation. The form of manual confirmation input can be clicking the "I have confirmed" button in the "Alarm Confirmation" window that pops up on the touch screen, and entering the employee number at the same time. Before confirmation, even if the pressure has returned to normal, the control module 150 will not automatically reset the second-level alarm, and the system will remain in a shutdown interlock state to ensure that the abnormality is noticed by humans.

[0035] In one embodiment, the alarm module 120 further includes an adaptive delay adjustment unit 121. The input terminal of the adaptive delay adjustment unit 121 is connected to the operation mode signal output terminal of the control module 150. The control module 150 generates an operation mode signal based on the current working status of the oil filter (which can be manually selected by the operator on the human-machine interaction module 160, or automatically determined by detecting the operating combination of the oil pump, heater, and vacuum pump). The operation modes include filtration mode, regeneration mode, and shutdown cooling mode.

[0036] The characteristics of pressure fluctuations differ in different modes: In filtration mode, the oil pump runs continuously and the pressure fluctuations are relatively stable, but the pressure rises slowly when the filter element is clogged. Therefore, the first delay time can be set to be longer (e.g., 10 seconds) to avoid false alarms. In regeneration mode, more sensitive monitoring of pressure changes is required, so the first delay time is shortened to 5 seconds. In shutdown cooling mode, the system pressure is lower, so the first delay time can be appropriately extended to 15 seconds. The adaptive delay adjustment unit 121 automatically adjusts the first delay time and / or the second delay time according to the current operating mode without manual intervention, thus improving adaptability under different operating conditions.

[0037] In one embodiment, the pressure relief module 130 includes a pilot-operated solenoid pressure relief valve 131 and a manual ball valve 132 connected in series with the pilot-operated solenoid pressure relief valve 131. The inlet of the pilot-operated solenoid pressure relief valve 131 is connected to the main oil line, and the outlet is connected to the return oil line. The manual ball valve 132 is installed upstream or downstream of the pilot-operated solenoid pressure relief valve 131. It is normally in a fully open state and can be manually closed when the pressure relief valve is under maintenance so that the valve can be disassembled without leaking oil.

[0038] The reset modes include automatic recovery mode and manual reset mode. Users can set the mode via the "Reset Mode Selection" switch of the human-machine interface module 160, and the setting value is stored in the holding register of the control module 150.

[0039] The automatic recovery mode is implemented as follows: The control module 150 monitors the system pressure in real time. When the pressure relief valve is opened, the pressure drops rapidly. The control module 150 continuously compares the current pressure with the recovery threshold (preset to 0.45MPa). When the pressure is lower than the recovery threshold and continues to exceed the recovery delay time (preset to 5 seconds), the control module 150 outputs a shut-off signal to the pilot-operated solenoid pressure relief valve 131. The pressure relief valve coil is de-energized, the valve closes, and the oil filter automatically resumes normal operation. The recovery delay time can prevent the valve from frequently opening and closing due to pressure fluctuations.

[0040] The manual reset mode is implemented as follows: After the pressure relief valve is opened, the control module 150 does not automatically close the valve, but keeps it open. Simultaneously, a prompt window appears on the human-machine interface module 160 stating "Pressure relief valve is open, please check and manually reset." The operator must first rule out the cause of overpressure (such as cleaning or replacing the filter element, or confirming the oil outlet valve is fully open), and then click the "Manual Reset" button on the human-machine interface module 160. Upon receiving this instruction, the control module 150 outputs a closing signal to the pilot-operated solenoid pressure relief valve 131. In manual reset mode, a timeout reminder can also be set. If the valve is not manually reset after a certain time (e.g., 30 minutes), the system will issue an audible and visual alarm.

[0041] In one embodiment, the pressure monitoring module 110 further includes a pressure change rate detection unit 113, which calculates the rate of change by dividing the difference in pressure sensor readings per unit time (e.g., 0.1 seconds) by time. The input of the pressure change rate detection unit 113 is connected to the output of the first pressure sensor 111 and the second pressure sensor 112, and its output is connected to the alarm module 120 and the control module 150.

[0042] When the change in system pressure per unit time exceeds the rate of change threshold (e.g., 2 MPa / s), it indicates that an extremely rapid pressure spike has occurred. This is usually a false signal caused by electromagnetic interference, loose sensor wiring, or vibration impact, rather than a true overpressure. At this time, the pressure change rate detection unit 113 outputs an "interference flag" signal. After receiving the flag, the alarm module 120 and the pressure relief module 130 are prohibited from triggering. This design effectively avoids false alarms and false pressure relief caused by instantaneous interference. At the same time, the control module 150 records the event as a "pressure spike interference event" for subsequent analysis of the equipment's electromagnetic environment.

[0043] It should be noted that the readings of the two pressure sensors are independently measured for rate of change. Normal alarm and pressure relief logic is only allowed when the rate of change of both sensors does not exceed the threshold. If the rate of change of one sensor exceeds the threshold while the other is normal, the system judges that the sensor is faulty and issues a corresponding fault alarm.

[0044] In one embodiment, such as Figure 3 As shown, the observation window 210 includes tempered glass 211, the thickness of which is not less than 8mm to meet the requirements of pressure resistance, oil resistance and temperature resistance. The tempered glass 211 is fixed to the opening of the box body by a fluororubber sealing ring 216 and a pressure plate 217 to ensure no leakage under an internal pressure of 0.8MPa.

[0045] The window frame 212 of the observation window 210 integrates an LED light 213 and an electric heating film 214. The LED light 213 is a ring-shaped white LED light strip that surrounds the inside of the glass. Its on / off state is controlled by the control module 150 through a relay output, or it can be automatically turned on according to the ambient brightness through a photosensitive sensor. The electric heating film 214 is a transparent conductive film (such as an ITO film) attached to the inside of the glass. Its control terminal is connected to the output terminal of the control module 150. The defogging activation condition of the electric heating film 214 is as follows: the control module 150 detects the temperature inside the window and the dew point temperature through a temperature and humidity sensor 215 installed near the observation window 210. When the temperature inside the window is less than 2°C below the dew point temperature, the electric heating film 214 is automatically activated to heat the window until the temperature is 5°C above the dew point temperature. This function ensures that the observation window 210 remains clear in high humidity environments or during winter operation, ensuring that the camera can capture clear images of the oil.

[0046] In one embodiment, the video monitoring module 140 includes a first camera 141 and a second camera 142. The first camera 141 is installed facing the observation window 210, with the lens axis perpendicular to the glass plane and the focal length selected as 6mm. The field of view covers the entire range of the observation window 210 and is used to capture the overall state of the oil. The second camera 142 is installed on the top of the oil filter housing, with a top-down installation angle and the lens pointing downwards at the surface of the oil. It is used to capture the foam accumulation and impurity sedimentation on the surface of the oil.

[0047] Both cameras are network cameras. The video monitoring module 140 supports multi-screen switching (the first camera 141, the second camera 142, or split-screen display can be shown on the human-machine interaction module 160), manual snapshot (click the "snap" button on the screen to save the current image), and recording storage function (recording can be manually started / stopped, or timed recording can be set). All captured images and recording files are automatically named according to date and time and stored in the hard drive of the industrial control computer. When the storage space is full, the oldest unmarked file is automatically overwritten. However, images and recordings associated with alarm events are marked as "important" and will not be automatically overwritten, requiring manual cleaning.

[0048] In one embodiment, the intelligent control system 100 for the transformer vacuum oil purifier further includes an image analysis module 170. The input terminal of the image analysis module 170 is connected to the data output terminal of the video monitoring module 140, and the output terminal of the image analysis module 170 is connected to the input terminal of the control module 150. The image analysis module 170 can run within an industrial computer and employs an algorithm library based on OpenCV or a lightweight deep learning model. This module can analyze real-time video images and automatically identify the following: Oil level recognition: By recognizing the boundary between oil and air (based on color threshold and edge detection), the proportion of the oil level in the field of view of the observation window 210 is calculated, and then the oil level height in the oil tank is calculated. When the oil level is lower than the set safety line, a "low oil level" warning is sent to the control module 150.

[0049] Bubble density detection: The background difference of the oil area is performed to extract the bubble outline and count the number of bubbles per unit area. When the bubble density exceeds the preset threshold, an "abnormal bubble" warning is issued, indicating that there may be a vacuum system leak or oil emulsification.

[0050] Color change trend: Extract the average RGB or HSV value of the oil area at regular intervals (e.g., 1 hour), record and generate a curve of change over time. If the color gradually darkens (e.g., shifts towards reddish-brown), it can be preliminarily judged that the oil is aging or contaminated, indicating that an oil sample needs to be taken for further testing.

[0051] The output of the image analysis module 170 serves as auxiliary monitoring information and is not directly linked to the safety interlock. However, the analysis results can be displayed on the human-machine interaction module 160, and users can decide whether to trigger a general alarm based on their settings.

[0052] In one embodiment, the intelligent control system 100 for the transformer vacuum oil purifier further includes a safety redundancy module 180. The safety redundancy module 180 includes a mechanical pressure switch 181. The mechanical pressure switch 181 is a normally closed pressure switch with a set value of 0.82MPa, which is installed in the oil circuit of the oil purifier. The normally closed contact of the mechanical pressure switch 181 is connected in series in the power circuit of the oil purifier heater and the oil pump. Specifically, the two ends of the contact are respectively connected to the neutral wire of the heater contactor coil circuit and the neutral wire (or live wire) of the oil pump contactor coil circuit, forming a hard interlock.

[0053] When the system pressure exceeds the mechanical safety threshold (e.g., 0.82 MPa), the diaphragm inside the mechanical pressure switch 181 pushes the microswitch, causing the normally closed contact to open. This opening action directly cuts off the power supply to the coils of the heater contactor and the oil pump contactor, thereby forcibly stopping the heater and the oil pump. This action does not depend on the control module 150, PLC program, or any electronic devices. It is a purely mechanical protection and meets the safety integrity level requirements. When the pressure returns to the normal range, the pressure switch automatically resets and the contacts close. However, the system requires manual restart of the heater and the oil pump. This safety redundancy module 180 is the last line of defense to prevent overpressure accidents in the event of electronic control system failure.

[0054] In one embodiment, the human-machine interaction module 160 is an industrial touch screen 161. Manual confirmation input includes a combination or selection of three methods: clicking the confirmation button on the screen, entering the employee number, and fingerprint recognition. For example, for a general second alarm, only clicking the confirmation button and entering the employee number are required; for an important second alarm (such as one that occurs again within 30 minutes), fingerprint recognition is required at the same time to confirm the operator's identity and record the responsibility.

[0055] Specifically, when the second alarm signal is triggered, the HMI displays an alarm confirmation dialog box, showing the current pressure, alarm time, and suggested handling measures (such as "Please check if the filter element is clogged and if the oil outlet valve is fully open"), and displays a "Confirm" button. After the operator clicks the confirm button, a soft keyboard pops up to enter their employee number. If the system is configured with a fingerprint module 162, it further requires the operator to press their fingerprint. All confirmation operations are recorded in log 163, including the time, operator's employee number, and confirmation method.

[0056] Before receiving manual confirmation, even if the system pressure has automatically returned to normal (e.g., pressure drop after a momentary disturbance), the control module 150 still maintains the shutdown interlock state corresponding to the second alarm signal: that is, the pressure relief valve remains open (if manual reset mode is selected), and the oil pump and heater must not be started unless a manual reset operation is performed. This design ensures that every serious overpressure event is known and handled by the operator, preventing potential faults from being overlooked due to automatic pressure drop.

[0057] In one embodiment, the first threshold is preferably 0.5 MPa, the second threshold is preferably 0.7 MPa, and the first delay time is 3 to 10 seconds, which can be adjusted according to the scale and operating conditions of the oil filter: For large oil filters (processing capacity ≥ 10000 L / h), due to the large system inertia and slow pressure change, the first delay time can be 10 seconds; for small oil filters (processing capacity ≤ 3000 L / h), the first delay time can be 3 seconds, and the second delay time is 1 to 3 seconds, usually 1 to 2 seconds. In this embodiment, the first delay is 8 seconds and the second delay is 1 second in filtration mode; the first delay is 5 seconds and the second delay is 1 second in regeneration mode; and the first delay is 10 seconds and the second delay is 2 seconds in shutdown cooling mode. All of the above parameters can be modified by authorized engineers through the human-machine interaction module 160.

[0058] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An intelligent control system for a transformer vacuum oil filtration machine, characterized in that, It includes a pressure monitoring module, an alarm module, a pressure relief module, a video monitoring module, a control module, and a human-machine interface module. The pressure monitoring module includes a first pressure sensor and a second pressure sensor. Both the first pressure sensor and the second pressure sensor are installed in the oil circuit of the oil filter to monitor the system pressure in real time. The signal output terminal of the pressure monitoring module is connected to the alarm module and the control module, respectively. The input terminal of the alarm module is connected to the signal output terminal of the pressure monitoring module. When the system pressure exceeds a first threshold and the duration exceeds a first delay time, a first alarm signal is triggered. When the system pressure exceeds a second threshold and the duration exceeds a second delay time, a second alarm signal is triggered. The second threshold is greater than the first threshold, and the second delay time is less than the first delay time. The alarm signal output terminal of the alarm module is connected to the human-machine interaction module and the control module. The pressure relief module is installed on the pressure relief pipeline of the oil filter. The control terminal of the pressure relief module is connected to the output terminal of the control module. When the system pressure exceeds the second threshold, the pressure relief module is opened. After pressure relief, the pressure relief module is automatically closed or waits for a manual reset signal according to the reset mode selected by the user. The video monitoring module is installed at the observation window and is used to collect images of the oil condition. The data output terminal of the video monitoring module is connected to the data input terminal of the control module. The first signal input terminal of the control module is connected to the alarm signal output terminal of the alarm module, the second signal input terminal of the control module is connected to the signal output terminal of the pressure monitoring module, and the data input terminal of the control module is connected to the data output terminal of the video monitoring module. When the first alarm signal or the second alarm signal is received, the video monitoring module is automatically controlled to capture an image and associate the image with the alarm event for storage. The human-machine interface module is bidirectionally connected to the control module and is used to display alarm information, real-time video footage, and receive manual confirmation input. When the second alarm signal is triggered, the control module needs to receive the manual confirmation input from the human-machine interface module before controlling the pressure relief module to reset or the system to resume operation.

2. The intelligent control system for the transformer vacuum oil purifier as described in claim 1, characterized in that, The alarm module also includes an adaptive delay adjustment unit. The input of the adaptive delay adjustment unit is connected to the operating mode signal output of the control module. The adaptive delay adjustment unit automatically adjusts the first delay time and the second delay time according to the current operating mode of the oil filter. The operating modes include filtration mode, regeneration mode and shutdown cooling mode.

3. The intelligent control system for the transformer vacuum oil purifier as described in claim 1, characterized in that, The pressure relief module includes a pilot-operated electromagnetic pressure relief valve and a manual ball valve connected in series with the pilot-operated electromagnetic pressure relief valve. The reset modes include automatic recovery mode and manual reset mode; Automatic recovery mode: When the system pressure drops below the recovery threshold after depressurization and the duration exceeds the recovery delay time, the control module controls the pilot-operated electromagnetic pressure relief valve to automatically close. Manual reset mode: The pilot-operated solenoid pressure relief valve remains open until the human-machine interface module receives a manual reset command, at which point the control module controls the pilot-operated solenoid pressure relief valve to close.

4. The intelligent control system for the transformer vacuum oil purifier as described in claim 3, characterized in that, The pressure monitoring module further includes a pressure change rate detection unit. The input terminal of the pressure change rate detection unit is connected to the output terminals of the first pressure sensor and the second pressure sensor. The output terminal of the pressure change rate detection unit is connected to the alarm module and the control module. When the change in system pressure within a unit time exceeds the change rate threshold, the alarm module and the pressure relief module are prohibited from triggering.

5. The intelligent control system for the transformer vacuum oil purifier as described in claim 1, characterized in that, The observation window includes tempered glass, and the window frame of the observation window integrates an LED light and an electric heating film. The control terminals of the LED light and the electric heating film are respectively connected to the output terminal of the control module. The electric heating film automatically starts defogging based on the difference between the temperature inside the window and the dew point temperature.

6. The intelligent control system for the transformer vacuum oil purifier as described in claim 1, characterized in that, The video monitoring module includes a first camera and a second camera. The first camera is installed facing the observation window to capture the overall state of the oil, and the second camera is installed on the top of the oil filter housing to capture the surface of the oil. The video monitoring module supports multi-view switching, manual snapshot, and storage functions.

7. The intelligent control system for the transformer vacuum oil purifier as described in claim 1, characterized in that, It also includes an image analysis module, the input of which is connected to the data output of the video surveillance module, and the output of which is connected to the input of the control module.

8. The intelligent control system for the transformer vacuum oil purifier as described in claim 1, characterized in that, It also includes a safety redundancy module, which contains a mechanical pressure switch. The mechanical pressure switch is installed in the oil circuit of the oil filter. The normally closed contact of the mechanical pressure switch is connected in series in the power circuit of the oil filter heater and the oil pump. When the system pressure exceeds the mechanical safety threshold, the normally closed contact of the mechanical pressure switch opens, directly cutting off the power supply to the heater and the oil pump.

9. The intelligent control system for the transformer vacuum oil purifier as described in claim 1, characterized in that, The human-machine interaction module is an industrial touch screen. The manual confirmation input includes clicking the confirmation button on the screen, entering the employee number, and fingerprint recognition. Before receiving the manual confirmation input, even if the system pressure returns to normal, the control module maintains the shutdown interlock state corresponding to the second alarm signal.

10. The intelligent control system for the transformer vacuum oil purifier as described in claim 1, characterized in that, The first threshold is 0.5 MPa, and the second threshold is 0.7 MPa; the first delay time is 3 to 10 seconds, and the second delay time is 1 to 3 seconds.

Images