Method and system for dynamically adjusting and controlling pressure of transformer oil sample collection

Abstract

The application belongs to the technical field of electric power robots. A transformer oil sample collection pressure dynamic adjustment control method and system are proposed. The flow characteristics are analyzed. Based on the real-time pressure and the environmental pressure difference, the oil density and the valve coefficient are combined to calculate the discharge flow. The feedforward-feedback composite control is executed. The pressure deviation is calculated and the instantaneous flow is estimated. The valve new opening degree instruction is output by using the adaptive control law containing the feedforward compensation term. The pressure mutation is actively inhibited. The multi-dimensional parameter online adaptive scheduling is implemented. The PID gain is dynamically adjusted according to the oil temperature and the oil type. The effective volume elastic modulus and the oil density are corrected. The application solves the problems of response lag and poor parameter adaptability of the traditional control, significantly improves the safety of the sampling process, and avoids the equipment damage caused by pressure impact.

Description

Technical Field

[0001] This invention relates to the field of power robot technology, specifically to a method and system for dynamic adjustment and control of transformer oil sample collection pressure. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Transformer oil sampling is a crucial step in power equipment condition monitoring and fault diagnosis, and the standardization and safety of the sampling process directly affect the accuracy of subsequent test results. With the advancement of smart grid construction, transformer oil sampling robots have gradually replaced manual operation, becoming the mainstream method. These robots typically employ multi-branch pipeline systems with syringes for negative or positive pressure sampling, controlling the oil flow direction and volume through precision solenoid valves. In existing technologies, control systems largely rely on traditional proportional-integral-derivative (PID) feedback regulation strategies. This involves using pressure sensors to monitor the oil pressure within the syringe cavity in real time, comparing it to a fixed threshold, and then adjusting the solenoid valve opening to maintain pressure stability. This single-loop feedback-based control architecture can maintain basic operation under relatively stable operating conditions and constant oil characteristics, forming the fundamental control logic of current automated sampling equipment.

[0004] However, existing control technologies struggle to handle the complex dynamic disturbances and variable environmental factors during transformer sampling, leading to an extremely high risk of injector rupture. Because insulating oil is compressible and its physical parameters vary significantly with temperature and oil type, rapid opening and closing of the sampling valve or pulsation of oil pressure can generate severe instantaneous flow surges. Traditional fixed-parameter feedback control inherently suffers from hysteresis, failing to respond promptly to sudden pressure changes; often, the surge occurs only after overpressure is detected. Furthermore, existing solutions lack an active feedforward compensation mechanism for inflow disturbances and cannot dynamically adjust control gain and model parameters based on real-time oil temperature and viscosity, resulting in a significant decrease in control accuracy under varying operating conditions. This passive, hysteresis-based adjustment method cannot fundamentally suppress pressure surges, making it extremely easy for the injector cavity pressure to exceed safety limits, causing equipment damage or even safety accidents. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method and system for dynamic adjustment and control of transformer oil sample collection pressure. By constructing three closely linked steps—flow characteristic analysis, feedforward-feedback composite control, and online adaptive scheduling of multi-dimensional parameters—precise and proactive control of the sampling pressure is achieved.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for dynamic adjustment and control of transformer oil sample collection pressure.

[0007] A method for dynamic adjustment and control of transformer oil sample collection pressure, wherein the oil sampling port of the transformer oil sampling robot is connected to the oil outlet of the oil sampling tank, the oil sampling port is connected to multiple branch pipelines through a main pipeline, a booster pump and a main solenoid valve are connected to the main pipeline, each branch pipeline is connected to an oil sampling syringe, and each branch pipeline is connected to a corresponding slave solenoid valve and a pressure sensor, including the following process: Flow characteristic analysis steps: Based on the real-time oil pressure in the oil syringe cavity collected by the pressure sensor, calculate the difference between the oil pressure and the ambient pressure as the pressure difference inside and outside the syringe. Feedforward-feedback composite control steps: Calculate the pressure deviation between the oil pressure and the preset safety threshold, and based on the estimated instantaneous flow rate, combine the proportional gain, integral gain, derivative gain, as well as the pressure difference inside and outside the injector, oil density, and rated flow coefficient, and output a new opening command from the solenoid valve through the adaptive control law calculation including the feedforward compensation term. Multidimensional parameter online adaptive scheduling steps: Obtain the current temperature and oil type information of the insulating oil, and dynamically adjust the proportional gain, integral gain, and derivative gain based on the temperature-viscosity mapping relationship or online viscosity estimation results.

[0008] In one implementation of the first aspect of the present invention, the preset security threshold is: ,in, for Preset safety threshold at any time For the material strength of the oil extraction syringe, For safety reasons, This is the margin coefficient. This represents the average peak pressure over the most recent sampling period.

[0009] In one implementation of the first aspect of the present invention, the flow characteristic analysis step further includes: obtaining the discharge flow rate by combining the oil density and the rated flow coefficient of the solenoid valve, wherein the discharge flow rate is: ,in, for The flow rate released from the solenoid valve is constantly monitored. To the rated flow coefficient of the solenoid valve, for The opening command of the solenoid valve is constantly received, and its value ranges from 0 to 1, where 0 represents the fully closed state and 1 represents the fully open state. for Constant pressure difference between the inside and outside of the syringe The density of the oil; The multi-dimensional parameter online adaptive scheduling step also includes: parameter correction of the effective bulk elastic modulus and density of the oil.

[0010] In one implementation of the first aspect of the present invention, a new opening command from the solenoid valve is output through an adaptive control law calculation including a feedforward compensation term, comprising: ,in, for The opening command of the solenoid valve is constantly received. For proportional gain, For integral gain, For differential gain, for Pressure deviation at any time and , The oil pressure in step one, To preset a safety threshold, For integration time variable, To measure instantaneous flow The estimated value, To the rated flow coefficient of the solenoid valve, The pressure difference between the inside and outside of the syringe. This represents the density of the oil.

[0011] Secondly, the present invention provides a dynamic adjustment and control system for transformer oil sample collection pressure.

[0012] A dynamic pressure regulation and control system for transformer oil sampling includes an oil sampling robot whose sampling port is connected to the oil outlet of an oil sampling tank. The sampling port is connected to multiple branch pipelines via a main pipeline. A booster pump and a main solenoid valve are connected to the main pipeline. Each branch pipeline is connected to an oil sampling syringe, and each branch pipeline is connected to a corresponding slave solenoid valve and a pressure sensor. The system includes: The flow characteristic analysis unit is configured to: calculate the difference between the oil pressure and the ambient pressure as the pressure difference inside and outside the syringe based on the oil pressure collected in real time by the pressure sensor. The feedforward-feedback composite control unit is configured to: calculate the pressure deviation between the oil pressure and the preset safety threshold, and based on the estimated instantaneous flow rate, combine the proportional gain, integral gain, derivative gain, and the pressure difference inside and outside the injector, the oil density, and the rated flow coefficient, and output a new opening command from the solenoid valve through an adaptive control law calculation including a feedforward compensation term; The multi-dimensional parameter online adaptive scheduling unit is configured to: acquire the current temperature and oil type information of the insulating oil, and dynamically adjust the proportional gain, integral gain, and derivative gain based on the temperature-viscosity mapping relationship or online viscosity estimation results.

[0013] In one implementation of the second aspect of the present invention, the feedforward-feedback composite control unit outputs a new opening command from the solenoid valve actuation through an adaptive control law calculation including a feedforward compensation term, comprising: ,in, for The opening command of the solenoid valve is constantly received. For proportional gain, For integral gain, For differential gain, for Pressure deviation at any time and , The oil pressure in step one, To preset a safety threshold, For integration time variable, To measure instantaneous flow The estimated value, To the rated flow coefficient of the solenoid valve, The pressure difference between the inside and outside of the syringe. This represents the density of the oil.

[0014] Thirdly, the present invention provides a dynamic adjustment and control system for transformer oil sample collection pressure.

[0015] A transformer oil sample collection pressure dynamic adjustment and control system includes a transformer oil sample collection robot and an oil collection tank. The oil collection port of the transformer oil sample collection robot is used to connect with the oil outlet of the oil collection tank. The oil collection port is connected to multiple branch pipelines through a main pipeline. A booster pump and a main solenoid valve are connected to the main pipeline. Each branch pipeline is connected to an oil collection syringe. Each branch pipeline is connected to a corresponding slave solenoid valve and a pressure sensor. The transformer oil sampling robot is equipped with a control terminal that communicates with the booster pump, main solenoid valve, slave solenoid valve, and pressure sensor. The control terminal is configured to execute the following process: Based on the real-time acquisition of oil pressure in the syringe cavity by the pressure sensor, the difference between the oil pressure and the ambient pressure is calculated as the pressure difference between the inside and outside of the syringe. The pressure deviation between the oil pressure and the preset safety threshold is calculated, and based on the estimated instantaneous flow rate, combined with the proportional gain, integral gain, derivative gain, pressure difference inside and outside the injector, oil density and rated flow coefficient, the new opening command from the solenoid valve is output through the adaptive control law calculation including feedforward compensation term. The system acquires information on the current temperature and type of insulating oil, and dynamically adjusts the proportional gain, integral gain, and derivative gain based on the temperature-viscosity mapping relationship or online viscosity estimation results.

[0016] In one optional implementation of the third aspect of the present invention, a two-position three-way solenoid valve is connected to the connecting pipe between the oil inlet and the oil outlet in the oil tank. The first port of the two-position three-way solenoid valve is connected to the oil inlet, the second port of the two-position three-way solenoid valve is connected to the air filter through a one-way valve, and the third port of the two-position three-way solenoid valve is connected to the oil sampling port of the transformer oil sampling robot. When the two-position three-way solenoid valve is energized, the first port and the third port are connected, which pressurizes the oil from the transformer inlet into the main pipeline, or draws the oil from the main pipeline through the booster pump. At this time, the two-position three-way solenoid valve is de-energized, and the second port and the third port are connected, opening the main solenoid valve and the waste oil tank solenoid valve connected to the main pipeline. The booster pump starts the oil pumping mode, drawing the residual oil in the main pipeline into the waste oil tank. At the same time, air also enters the waste oil tank from the air filter and the check valve until there is no oil in the main pipeline.

[0017] Fourthly, the present invention provides a computer device for mounting on a transformer oil sampling robot. The oil sampling port of the transformer oil sampling robot is connected to the oil outlet of the oil sampling tank. The oil sampling port is connected to multiple branch pipelines through a main pipeline. A booster pump and a main solenoid valve are connected to the main pipeline. Each branch pipeline is connected to an oil sampling syringe. Each branch pipeline is connected to a corresponding slave solenoid valve and a pressure sensor. The computer device includes: a processor and a computer-readable storage medium. A processor, adapted to execute computer programs; A computer-readable storage medium storing a computer program, which, when executed by a processor, performs the following processes: Based on the real-time acquisition of oil pressure in the syringe cavity by the pressure sensor, the difference between the oil pressure and the ambient pressure is calculated as the pressure difference between the inside and outside of the syringe. The pressure deviation between the oil pressure and the preset safety threshold is calculated, and based on the estimated instantaneous flow rate, combined with the proportional gain, integral gain, derivative gain, pressure difference inside and outside the injector, oil density and rated flow coefficient, the new opening command from the solenoid valve is output through the adaptive control law calculation including feedforward compensation term. The system acquires information on the current temperature and type of insulating oil, and dynamically adjusts the proportional gain, integral gain, and derivative gain based on the temperature-viscosity mapping relationship or online viscosity estimation results.

[0018] Fifthly, the present invention provides a computer-readable storage medium for mounting on a transformer oil sampling robot. The oil sampling port of the robot is connected to the oil outlet of an oil sampling tank. The oil sampling port is connected to multiple branch pipelines via a main pipeline. A booster pump and a main solenoid valve are connected to the main pipeline. Each branch pipeline is connected to an oil sampling syringe and a corresponding slave solenoid valve and pressure sensor. The computer-readable storage medium stores a computer program adapted to be loaded by a processor and executed as follows: Based on the real-time acquisition of oil pressure in the syringe cavity by the pressure sensor, the difference between the oil pressure and the ambient pressure is calculated as the pressure difference between the inside and outside of the syringe. The pressure deviation between the oil pressure and the preset safety threshold is calculated, and based on the estimated instantaneous flow rate, combined with the proportional gain, integral gain, derivative gain, pressure difference inside and outside the injector, oil density and rated flow coefficient, the new opening command from the solenoid valve is output through the adaptive control law calculation including feedforward compensation term. The system acquires information on the current temperature and type of insulating oil, and dynamically adjusts the proportional gain, integral gain, and derivative gain based on the temperature-viscosity mapping relationship or online viscosity estimation results.

[0019] Compared with the prior art, the beneficial effects of the present invention are: This invention innovatively proposes a dynamic pressure regulation and control method for a transformer oil sampling robot, and develops a dynamic pressure regulation and control system. Through three closely linked steps—flow characteristic analysis, feedforward-feedback composite control, and multi-dimensional parameter online adaptive scheduling—precise and proactive control of the sampling pressure is achieved. First, the discharge flow characteristics are accurately analyzed based on the difference between real-time pressure and ambient pressure. Then, using an adaptive control law including a feedforward compensation term, the instantaneous flow estimate is directly integrated into the calculation of the opening command. Simultaneously, the control gain and fluid physical parameters are dynamically adjusted according to oil temperature and oil type, thus solving the valve... The invention addresses the problems of large flow surges, delayed response, and low control accuracy during start-up and shutdown by introducing a feedforward compensation mechanism. This mechanism can calculate and output cancellation commands in advance at the moment of disturbance, overcoming the shortcomings of traditional pure feedback control that cannot suppress pressure surges in time due to detection delays. This achieves precise and proactive control of the sampling pressure, avoiding the risk of syringe bursting due to excessive pressure surges. At the same time, this invention overcomes the limitations of fixed control parameters in adapting to changes in the viscosity, density, and bulk modulus of insulating oil with temperature and oil type. Through online adaptive scheduling of multi-dimensional parameters, the accuracy of the control model under different operating conditions is ensured.

[0020] This invention significantly improves the safety and robustness of transformer oil sampling, ensuring that the oil pressure inside the syringe cavity remains within a dynamically set safety threshold range. By real-time correction of the effective bulk modulus and oil density, it avoids the accumulation of control errors caused by model parameter mismatch. This invention fundamentally avoids the risk of syringe bursting due to excessive pressure impact, eliminates potential equipment damage, ensures the continuous stability of sampling operations, and improves the quality and reliability of power equipment condition monitoring data acquisition.

[0021] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0023] Figure 1 A schematic diagram of a transformer oil sampling robot and an oil sampling tank provided as an exemplary embodiment of the present invention; Figure 2 A schematic diagram of a pipeline switching system provided as an exemplary embodiment of the present invention; Figure 3 A schematic diagram of an oil sample collection process provided for an exemplary embodiment of the present invention; Figure 4 A flowchart illustrating a method for dynamically adjusting and controlling the pressure of transformer oil sample collection, provided as an exemplary embodiment of the present invention; Figure 5 A schematic diagram of the principle of a transformer oil sample collection pressure dynamic adjustment control system provided as an exemplary embodiment of the present invention; Figure 6 A schematic diagram of a computer device provided as an exemplary embodiment of the present invention; The components include: 1. Transformer oil sample collection robot; 2. Oil sampling tank; 3. Oil sampling port; 4. Oil outlet; 5. Oil inlet; 6. Air inlet; 7. Air filter; 8. First check valve; 9. Second check valve; 10. Temperature transmitter; 11. Booster pump; 12. Two-position three-way solenoid valve; 13. Main solenoid valve; 14. First slave solenoid valve; 15. Second slave solenoid valve; 16. Third slave solenoid valve; 17. Fourth slave solenoid valve; 18. Fifth slave solenoid valve; 19. Sixth slave solenoid valve; 20. 21. Seventh solenoid valve; 22. Eighth solenoid valve; 23. First pressure sensor; 24. Second pressure sensor; 25. Third pressure sensor; 26. Fourth pressure sensor; 27. Fifth pressure sensor; 28. Sixth pressure sensor; 29. ​​Seventh pressure sensor; 30. First syringe; 31. Second syringe; 32. Third syringe; 33. Reserved port for oil chromatograph; 34. Fourth syringe; 35. Fifth syringe; 36. Sixth syringe; 37. Waste oil tank. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0026] This implementation proposes a method for dynamic adjustment and control of transformer oil sample collection pressure, such as... Figure 1 and Figure 2 As shown, the oil sampling port 3 of the transformer oil sampling robot 1 is used to connect with the oil outlet 4 of the oil sampling tank 2. The oil sampling port 3 is connected to multiple branch pipelines through the main pipeline. The main pipeline is connected to a booster pump 11 and a main solenoid valve 13. Each branch pipeline is connected to an oil sampling syringe. Each branch pipeline is connected to a corresponding slave solenoid valve and a pressure sensor.

[0027] More specifically, the transformer oil sampling robot 1 is equipped with an oil sampling port 3. The oil sampling port 3 is connected in series with a second one-way valve 9 and a main solenoid valve 13 via pipelines. A temperature transmitter 10 is connected in parallel to a branch line on the pipeline between the oil sampling port 3 and the second one-way valve 9 for real-time monitoring of the oil temperature. In addition, the oil sampling tank 2 is equipped with an independent air intake module, including an air intake port 6, which is connected in series with an air filter 7, a first one-way valve 8, and then connected to port A of a two-position three-way solenoid valve 12. At the same time, the oil inlet port 5 is connected to port B of the two-position three-way solenoid valve 12, and the common output port P of the valve is connected to the oil outlet port 4.

[0028] In this implementation, when the two-position three-way solenoid valve 12 is energized, the first port (i.e., port B) is connected to the third port (i.e., port P), which pumps the oil from the transformer inlet into the main pipeline or draws it into the main pipeline through the booster pump 11. At this time, the two-position three-way solenoid valve is de-energized, and the second port (i.e., port A) is connected to the third port, opening the main solenoid valve 13 and the waste oil tank solenoid valve (i.e., the eighth slave solenoid valve 21) connected to the main pipeline. The booster pump 11 starts the oil pumping mode, drawing the residual oil in the main pipeline into the waste oil tank. At the same time, air also enters the waste oil tank 36 from the air filter 7 and the first one-way valve 8 until there is no oil in the main pipeline.

[0029] The downstream pipeline of the main solenoid valve 13 serves as the main pipeline of the pipeline switching system. A booster pump 11 is connected to it to provide sampling power. A first pressure sensor 22 is provided between the inlet and outlet of the booster pump 11 or at the bypass position to monitor the pressure of the main pipeline.

[0030] The main pipeline branches into multiple parallel branch pipelines, each connecting to a different actuator: First branch: connected to the first solenoid valve 14, with a second pressure sensor 23 at its inlet and a first syringe 29 at its outlet; Second branch: connected to the second solenoid valve 15, with a third pressure sensor 24 at its inlet and a second syringe 30 at its outlet; The third branch is connected to the third solenoid valve 16, which has a fourth pressure sensor 25 at its inlet and a third syringe 31 at its outlet. Fourth branch: Connects to the fourth solenoid valve 17, whose outlet is directly connected to the reserved oil chromatograph port 32; Fifth branch: connected to the fifth solenoid valve 18, with a fifth pressure sensor 26 at its inlet and a fourth syringe 33 at its outlet; The sixth branch is connected to the sixth solenoid valve 19, which has a sixth pressure sensor 27 at its inlet and a fifth syringe 34 at its outlet. Seventh branch: connected to the seventh solenoid valve 20, with a seventh pressure sensor 28 at its inlet and a sixth syringe 35 at its outlet; Eighth branch: Connected to the eighth solenoid valve 21, its outlet pipeline extends to the waste oil tank 36 for the discharge of waste oil or cleaning fluid.

[0031] Each pressure sensor in the aforementioned branch pipeline collects the oil pressure in the corresponding syringe cavity in real time and feeds the signal back to the control terminal for dynamic pressure adjustment of each syringe, thereby achieving independent and precise control of the opening degree of each solenoid valve.

[0032] like Figure 3 As shown, the oil sampling process of the transformer oil sampling robot 1 includes the following steps: Step 1: System initialization and status monitoring.

[0033] Oil inlet 3 is connected to oil outlet 4 of oil tank 2. The system first performs environmental and operating condition detection: Determine if the temperature is normal: Use temperature transmitter 10 to determine if the current insulating oil temperature is within the allowable range; if not, terminate the process or wait; if yes, proceed to the next step. Determine if the pressure is normal: Monitor the pressure of the main pipeline or inlet (which can be monitored using the first pressure sensor 22). If the pressure is normal, directly open the main solenoid valve 13 to prepare for operation. If the pressure is abnormal, further determine whether the pressure is too high or too low: If the pressure is too high, execute the oil discharge or pressure relief logic (corresponding to the right process branch). If the pressure is too low, close the main solenoid valve 13 and start the booster pump 11 until the pressure returns to the normal range.

[0034] Step 2: Pipeline cleaning and pretreatment stage.

[0035] Before formal sampling, the system undergoes a rigorous cleaning procedure to eliminate any contamination of the samples by residual tubing: Pipeline cleaning is performed by opening the first solenoid valve 14 and the eighth solenoid valve 21, while closing the remaining solenoid valves. The oil flows through the main pipeline and is then directly discharged into the waste oil tank 36 via the eighth branch, thus flushing the pipeline. The system continuously monitors whether the pipeline cleaning is complete; if not, cleaning continues until completion, at which point it enters the rinsing stage. First syringe oil rinsing: Open only the first solenoid valve 14, close all others, and use the first syringe 29 to draw a small amount of oil for rinsing the inner wall. The system cyclically checks whether the first syringe has been rinsed completely to ensure that the internal environment of the syringe meets the sampling requirements.

[0036] Step 3: Exhausting and formal sampling stage (taking the first syringe as an example).

[0037] After preprocessing, the system enters a precision sampling cycle for each syringe: To drain oil: Open the first solenoid valve 14 (or in conjunction with the eighth solenoid valve 21), while closing the remaining solenoid valves; or, under specific logic, shut down the booster pump 11 to drain oil using gravity or back pressure, aiming to remove air bubbles from the pipeline and syringe. The system determines in real time whether the first syringe has finished draining oil.

[0038] The first syringe performs oil sampling: After confirming that the venting is complete, the main solenoid valve 13 is opened (or the booster pump 11 is started) to establish positive pressure, keeping the first slave solenoid valve 14 open and the others closed, driving the first syringe 29 to perform the formal sampling action. The system continuously monitors whether the first syringe has finished sampling. During this period, the logic process of the pressure dynamic regulation and control method of the present invention runs in real time, and through feedback and feedforward compensation such as the second pressure sensor 23, the valve opening is precisely controlled to prevent pressure shock.

[0039] Step 4: Task completion and multi-channel switching.

[0040] Oil sampling completed: After the first syringe 29 completes sampling, the system closes all solenoid valves and stops the booster pump 11, marking the end of a single sampling operation.

[0041] Other syringes take oil in sequence: The system controls the second syringe 30, the third syringe 31, the fourth syringe 33, the fifth syringe 34 and the sixth syringe 35 to take oil in sequence according to the preset program. The oil taking process is similar to the steps of the first syringe mentioned above (i.e., it includes sub-processes such as venting and sampling).

[0042] Finally, the oil extraction operation was completed once all the pre-selected syringes had finished their work.

[0043] like Figure 4 The diagram illustrates the specific process of the transformer oil sample collection pressure dynamic adjustment and control method of the present invention. It aims to proactively suppress pressure surges during sampling through a theoretically rigorous closed-loop control system, fundamentally eliminating the risk of syringe bursting. The method includes the following steps: S401: Establish a dynamic mathematical model of the system.

[0044] The system controls the hydraulic pressure within the syringe cavity. Establishing a dynamic model is a prerequisite for controller design. Considering the compressibility of the oil, the discharge flow through the solenoid valve, and external disturbances, a pressure differential equation is established based on mass conservation and fluid mechanics: (1); in: This refers to the effective bulk modulus of the insulating oil (which is related to the oil type and temperature). This refers to the constant volume of the syringe cavity and related tubing. The instantaneous flow rate flowing in from the transformer sampling valve is the main source of disturbance, and its sudden changes are caused by valve opening and closing and oil pressure pulsation. The discharge flow through the controlled solenoid valve is the control variable of the system.

[0045] S402: Flow characteristic equation of the actuator (solenoid valve).

[0046] Release flow By solenoid valve opening (0 for fully closed, 1 for fully open) and the internal pressure of the syringe Environmental pressure difference The characteristics of this decision can be described using a simplified model: (2); in: This is the valve's rated flow coefficient; Internal pressure of the syringe Environmental pressure difference; This refers to the oil density (which varies with temperature and type).

[0047] S403: Adaptive PID control.

[0048] An adaptive PID control with feedforward compensation is employed, and the control system uses the measured value from the pressure sensor. With preset safety threshold deviation As input, calculate the solenoid valve opening command. The following control law is adopted: (3); The formula consists of two parts: (1) Feedback part (PID): These are proportional, integral, and derivative gains, used to eliminate steady-state errors and suppress rapid fluctuations. (2) Feedforward compensation section: For the main disturbance The estimated value is obtained by monitoring the rate of change of the sampling valve control signal or the auxiliary pressure sensor at the inlet end. The inflow flow is estimated in real time, and the required venting opening is calculated in advance to offset the flow, which greatly improves the system's shock resistance.

[0049] S404: Parameter adaptive mechanism.

[0050] To ensure different oil temperatures And oil products (affect) The control system exhibits optimal performance under these conditions, and incorporates a built-in online parameter adaptive module. Gain scheduling: Establishing controller parameters Mapping relationship with oil characteristic parameters The PID parameters can be dynamically adjusted by consulting the temperature-viscosity curve table or online viscosity estimation. Model update: Adjusting model parameters based on real-time data and Fine-tuning was performed to make the flow equation The calculations are more accurate.

[0051] S405: Dynamic setting of safety threshold.

[0052] Safety threshold It is not a fixed value, but depends on the strength of the syringe material. Current oil quality and historical peak pressure statistics are dynamically set by the following formula: (4); in, For safety reasons, This is the average peak pressure over the recent sampling period. This is the margin coefficient. This method ensures that the safety threshold can absolutely guarantee safety while adapting to actual working conditions and avoiding unnecessary frequent actions.

[0053] Through the rigorous theoretical system based on dynamic model, feedforward-feedback composite control, parameter adaptation and dynamic threshold setting, the present invention can achieve precise and robust control of transformer oil sampling pressure, effectively cope with pressure shocks caused by oil temperature changes, oil switching and valve operation, and ensure that the sampling process is safe and explosion-free.

[0054] In summary, this invention designs a pipeline oil leakage prevention valve module structure, which can completely remove residual oil from the pipeline, preventing residual oil sample contamination and leakage. It also designs a pipeline oil leakage prevention method, which completely removes residual oil from the pipeline, preventing residual oil sample contamination and leakage. A self-sealing one-way valve is used to prevent oil leakage during pipeline connection. The pipeline switching system of this invention is integrated into the transformer oil sampling robot. After the transformer oil sampling robot arrives at the sampling point once, it can automatically perform multiple steps of pipeline flushing, air bubble removal, formal oil sample collection, and temporary storage through the pipeline switching system. This eliminates the need for the robot to travel back and forth to the oil tank within a single sampling cycle, achieving fully autonomous closed-loop operation. The system utilizes a pressure sensor and control system to monitor the syringe pressure in real time. The control system is configured to dynamically adjust the opening of the solenoid valve based on the feedback from the pressure sensor, to smooth oil pressure shocks caused by oil temperature changes, oil type switching, or valve opening and closing, maintaining the internal pressure of each syringe within a safe threshold.

[0055] Optionally, in some other implementations, while existing control methods can compensate for existing pressure surges, they cannot predict upcoming pressure shocks. When sampling valves open and close, or when disturbances such as oil circuit pulsation occur, there is still a short control window, which can easily cause minor pressure overshoot. Therefore, optionally, calculation... The rate of change of pressure shock at any given moment includes: (5); in, for The predicted rate of change of pressure shock at any given moment, in Pa / s; This is the impact amplification factor, in dimensionless form. for The rate of change of instantaneous inflow at any given moment, expressed in m³ / s². This is the effective bulk elastic modulus of insulating oil, expressed in Pa. This refers to the constant volume of the syringe cavity and related tubing, expressed in m³. This is the pressure difference coupling coefficient, with units of 1 / s; for The pressure difference between the inside and outside of the syringe at any given time, expressed in Pa.

[0056] By coupling the rate of change of inflow rate with the current pressure difference, the trend of pressure shock can be predicted 50-200 ms in advance. This shifts control from in-process compensation to pre-emptive prediction, effectively eliminating the control window at the initial stage of disturbances and avoiding minor pressure overshoot. The rate of change of pressure shock is predicted. As the basis for the correction of the feedforward compensation term, if (If the pressure is anticipated to increase), then the existing feedforward compensation item will be adjusted accordingly. Based on this, the opening command of the solenoid valve is pre-adjusted, and the pre-adjustment range is... Positive correlation; if (If no upward pressure is anticipated), the original feedforward compensation term will remain unchanged to avoid over-adjustment.

[0057] Optionally, in some other implementations, multi-dimensional parameter adaptive scheduling adjusts the PID gain only through temperature-viscosity mapping, without considering the nonlinear coupling relationship between viscosity changes and gain adjustment. This may easily lead to a mismatch between the gain adjustment and the actual viscosity change, especially when the oil temperature changes abruptly, causing fluctuations in control accuracy. Therefore, optionally, for The PID gain after time correction is calculated: (6); in, for PID gain after time correction ( Proportion, integral, Differential), the unit is the corresponding original gain unit ( Dimensionless 1 / s s); This is the PID gain reference value, in units of the same. ; This is the viscosity sensitivity coefficient, with units of m² / s; for The real-time kinematic viscosity of the insulating oil, expressed in m² / s; This is the standard kinematic viscosity of insulating oil, expressed in m² / s. for The predicted rate of change of pressure shock at any given moment, in Pa / s; for The preset safety threshold at any given time, in Pa.

[0058] By introducing the exponential nonlinear relationship between viscosity and gain, the optimal PID gain is precisely matched for different viscosities, solving the problem of gain adjustment mismatch when oil temperature changes abruptly. Furthermore, by incorporating the predicted rate of change of pressure shock, the gain adjustment simultaneously considers both oil characteristics and pressure shock trends, achieving dual adaptive correction. The corrected... , , It is directly used as the final output value of the multi-dimensional parameter online adaptive scheduling unit, replacing the original gain value obtained only through temperature-viscosity mapping, and substituted into the adaptive control law of feedforward-feedback composite control for the calculation of the solenoid valve opening command.

[0059] Optionally, in some other implementations, the estimated value of the instantaneous inflow in the original feedforward compensation term is... There may be some estimation error, and this error accumulates with changes in pipeline conditions and oil viscosity, causing the accuracy of feedforward compensation to gradually decrease and fail to completely offset the impact of flow disturbances. Therefore, optionally, compensation can be made for the flow estimate, including: (7); Estimated flow rate after compensation: (8); in, for The flow disturbance compensation coefficient at any given time, in dimensionless form; for The actual oil pressure inside the syringe cavity at any given time, in Pa; for The preset safety threshold at any given time, in Pa; Cumulative calibration time, in seconds; This is a symbolic function, and its unit is dimensionless. for The predicted rate of change of pressure shock at any given moment, in Pa / s; for The instantaneous inflow rate estimate after time-compensation, in m³ / s; for The original instantaneous inflow estimate at any given time, in m³ / s.

[0060] This invention quantifies the cumulative degree of flow estimation error by integrating the pressure deviation over time, thereby achieving self-correction of the compensation coefficient, real-time correction of the flow estimation value, and elimination of the cumulative effect of estimation error. It also introduces a sign function combined with the pressure shock prediction rate of change, so that the correction direction of the compensation coefficient is consistent with the pressure deviation trend, avoiding pressure fluctuations caused by reverse correction.

[0061] The compensated instantaneous inflow rate estimate Replace the original feedforward-feedback composite control law Substituting this into the opening instruction formula (3), we obtain a more accurate feedforward compensation term, thereby achieving error-free cancellation of flow disturbances.

[0062] Figure 5 A transformer oil sample collection pressure dynamic adjustment and control system is shown, comprising: The flow characteristic analysis unit 501 is configured to: calculate the difference between the oil pressure and the ambient pressure as the pressure difference inside and outside the syringe based on the oil pressure collected in real time by the pressure sensor in the oil syringe cavity. The feedforward-feedback composite control unit 502 is configured to: calculate the pressure deviation between the oil pressure and the preset safety threshold, and based on the estimated instantaneous flow rate, combine the proportional gain, integral gain, derivative gain, and the pressure difference inside and outside the injector, the oil density, and the rated flow coefficient, and output a new opening command from the solenoid valve through an adaptive control law calculation including a feedforward compensation term. The multi-dimensional parameter online adaptive scheduling unit 503 is configured to: obtain the current temperature and oil type information of the insulating oil, and dynamically adjust the proportional gain, integral gain, and derivative gain based on the temperature-viscosity mapping relationship or the online viscosity estimation result.

[0063] It is understood that the aforementioned units can be individually or entirely merged into one or more other units, or some of the units can be further divided into multiple functionally smaller units. This achieves the same operation without affecting the technical effects of the embodiments of the present invention. The aforementioned units are based on logical functional division. In practical applications, the function of one unit can be implemented by multiple units, or the function of multiple units can be implemented by one unit. In other embodiments of the present invention, the system may also include other units. In practical applications, these functions can also be implemented with the assistance of other units, and can be implemented collaboratively by multiple units.

[0064] According to another embodiment of the present invention, the system of this embodiment can be constructed by running a computer program (including program code) capable of performing the steps involved in the corresponding method of the present invention on a general-purpose computing device, such as a computer, which includes processing elements and storage elements such as a central processing unit (CPU), random access memory (RAM), and read-only memory (ROM). The computer program can be recorded on, for example, a computer-readable recording medium, loaded into the aforementioned computing device through the computer-readable recording medium, and run therein.

[0065] Figure 6 A computer device is shown for mounting on a transformer oil sample collection robot. The computer device includes a processor 601, a communication interface 602, and a computer-readable storage medium 603. The processor 601, communication interface 602, and computer-readable storage medium 603 can be connected via a bus or other means.

[0066] The communication interface 602 is used to receive and send data. The computer-readable storage medium 603 can be stored in the memory of the electronic device. The computer-readable storage medium 603 is used to store computer programs, which include program instructions. The processor 601 is used to execute the program instructions stored in the computer-readable storage medium 603.

[0067] The processor 601 is the computing and control core of an electronic device. It is suitable for implementing one or more instructions, specifically for loading and executing one or more instructions to achieve the corresponding method flow or corresponding function.

[0068] Processor 601 is configured to perform the following procedure: Based on the real-time acquisition of oil pressure in the syringe cavity by the pressure sensor, the difference between the oil pressure and the ambient pressure is calculated as the pressure difference between the inside and outside of the syringe. The pressure deviation between the oil pressure and the preset safety threshold is calculated, and based on the estimated instantaneous flow rate, combined with the proportional gain, integral gain, derivative gain, pressure difference inside and outside the injector, oil density and rated flow coefficient, the new opening command from the solenoid valve is output through the adaptive control law calculation including feedforward compensation term. The system acquires information on the current temperature and type of insulating oil, and dynamically adjusts the proportional gain, integral gain, and derivative gain based on the temperature-viscosity mapping relationship or online viscosity estimation results.

[0069] This invention also provides a computer-readable storage medium for mounting on a transformer oil sampling robot. The computer-readable storage medium is a memory device in an electronic device used to store programs and data. It is understood that the computer-readable storage medium here can include both built-in storage media in an electronic device and extended storage media supported by the electronic device. The computer-readable storage medium provides storage space for the processing system of the electronic device.

[0070] Furthermore, this storage space also contains one or more instructions suitable for loading and execution by the processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory; alternatively, it can also be at least one computer-readable storage medium located remotely from the aforementioned processor.

[0071] In one embodiment, the computer-readable storage medium stores one or more instructions; the processor loads and executes the one or more instructions stored in the computer-readable storage medium to perform the following process: Based on the real-time acquisition of oil pressure in the syringe cavity by the pressure sensor, the difference between the oil pressure and the ambient pressure is calculated as the pressure difference between the inside and outside of the syringe. The pressure deviation between the oil pressure and the preset safety threshold is calculated, and based on the estimated instantaneous flow rate, combined with the proportional gain, integral gain, derivative gain, pressure difference inside and outside the injector, oil density and rated flow coefficient, the new opening command from the solenoid valve is output through the adaptive control law calculation including feedforward compensation term. The system acquires information on the current temperature and type of insulating oil, and dynamically adjusts the proportional gain, integral gain, and derivative gain based on the temperature-viscosity mapping relationship or online viscosity estimation results.

[0072] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed in this invention can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can implement the described functions using different methods for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0073] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of the present invention is generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in or transmitted through a computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic cable, digital cable) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that a computer can access or a data processing device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state drive), etc.

[0074] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for dynamic adjustment and control of transformer oil sample collection pressure, characterized in that, The oil sampling port of the transformer oil sampling robot is connected to the oil outlet of the oil sampling tank. The oil sampling port is connected to multiple branch pipelines through a main pipeline. A booster pump and a main solenoid valve are connected to the main pipeline. Each branch pipeline is connected to an oil sampling syringe, and each branch pipeline is connected to a corresponding slave solenoid valve and a pressure sensor. The process includes the following: Flow characteristic analysis steps: Based on the real-time oil pressure in the oil syringe cavity collected by the pressure sensor, calculate the difference between the oil pressure and the ambient pressure as the pressure difference inside and outside the syringe. Feedforward-feedback composite control steps: Calculate the pressure deviation between the oil pressure and the preset safety threshold, and based on the estimated instantaneous flow rate, combine the proportional gain, integral gain, derivative gain, as well as the pressure difference inside and outside the injector, oil density, and rated flow coefficient, and output a new opening command from the solenoid valve through the adaptive control law calculation including the feedforward compensation term. Multidimensional parameter online adaptive scheduling steps: Obtain the current temperature and oil type information of the insulating oil, and dynamically adjust the proportional gain, integral gain, and derivative gain based on the temperature-viscosity mapping relationship or online viscosity estimation results.

2. The method for dynamic adjustment and control of transformer oil sample collection pressure as described in claim 1, characterized in that, The preset security threshold is: ,in, for Preset safety threshold at any time For the material strength of the oil extraction syringe, For safety reasons, This is the margin coefficient. This represents the average peak pressure over the most recent sampling period.

3. The method for dynamic adjustment and control of transformer oil sample collection pressure as described in claim 1, characterized in that, The flow characteristic analysis steps also include: combining the oil density and the rated flow coefficient of the solenoid valve to obtain the discharge flow rate, which is: ,in, for The flow rate released from the solenoid valve is constantly monitored. To the rated flow coefficient of the solenoid valve, for The opening command of the solenoid valve is constantly received, and its value ranges from 0 to 1, where 0 represents the fully closed state and 1 represents the fully open state. for Constant pressure difference between the inside and outside of the syringe The density of the oil; The multi-dimensional parameter online adaptive scheduling step also includes: parameter correction of the effective bulk elastic modulus and density of the oil.

4. The method for dynamic adjustment and control of transformer oil sample collection pressure as described in claim 1, characterized in that, In the feedforward-feedback composite control step, through the calculation of the adaptive control law including the feedforward compensation term, a new opening command from the solenoid valve action is output, including: ,in, for The opening command of the solenoid valve is constantly received. For proportional gain, For integral gain, For differential gain, for Pressure deviation at any time and , The oil pressure mentioned in step one, To preset a safety threshold, For integration time variable, To measure instantaneous flow The estimated value, To the rated flow coefficient of the solenoid valve, The pressure difference between the inside and outside of the syringe. This represents the density of the oil.

5. A dynamic pressure adjustment and control system for transformer oil sample collection, characterized in that, The oil sampling port of the transformer oil sampling robot is connected to the oil outlet of the oil sampling tank. The oil sampling port is connected to multiple branch pipelines via a main pipeline. A booster pump and a main solenoid valve are connected to the main pipeline. Each branch pipeline is connected to an oil sampling syringe, and each branch pipeline is connected to a corresponding slave solenoid valve and a pressure sensor, including: The flow characteristic analysis unit is configured to: calculate the difference between the oil pressure and the ambient pressure as the pressure difference inside and outside the syringe based on the oil pressure collected in real time by the pressure sensor. The feedforward-feedback composite control unit is configured to: calculate the pressure deviation between the oil pressure and the preset safety threshold, and based on the estimated instantaneous flow rate, combine the proportional gain, integral gain, derivative gain, and the pressure difference inside and outside the injector, the oil density, and the rated flow coefficient, and output a new opening command from the solenoid valve through an adaptive control law calculation including a feedforward compensation term; The multi-dimensional parameter online adaptive scheduling unit is configured to: acquire the current temperature and oil type information of the insulating oil, and dynamically adjust the proportional gain, integral gain, and derivative gain based on the temperature-viscosity mapping relationship or online viscosity estimation results.

6. The transformer oil sample collection pressure dynamic adjustment and control system as described in claim 5, characterized in that, In the feedforward-feedback composite control unit, through adaptive control law calculation including feedforward compensation terms, a new opening command from the solenoid valve actuation is output, including: ,in, for The opening command of the solenoid valve is constantly received. For proportional gain, For integral gain, For differential gain, for Pressure deviation at any time and , The oil pressure mentioned in step one, To preset a safety threshold, For integration time variable, To measure instantaneous flow The estimated value, To the rated flow coefficient of the solenoid valve, The pressure difference between the inside and outside of the syringe. This represents the density of the oil.

7. A dynamic pressure adjustment and control system for transformer oil sample collection, characterized in that, It includes a transformer oil sampling robot and an oil sampling tank. The oil sampling port of the transformer oil sampling robot is used to connect with the oil outlet of the oil sampling tank. The oil sampling port is connected to multiple branch pipelines through the main pipeline. A booster pump and a main solenoid valve are connected to the main pipeline. Each branch pipeline is connected to an oil sampling syringe. Each branch pipeline is connected to a corresponding slave solenoid valve and a pressure sensor. The transformer oil sampling robot is equipped with a control terminal that communicates with the booster pump, main solenoid valve, slave solenoid valve, and pressure sensor. The control terminal is configured to execute the following process: Based on the real-time acquisition of oil pressure in the syringe cavity by the pressure sensor, the difference between the oil pressure and the ambient pressure is calculated as the pressure difference between the inside and outside of the syringe. The pressure deviation between the oil pressure and the preset safety threshold is calculated, and based on the estimated instantaneous flow rate, combined with the proportional gain, integral gain, derivative gain, pressure difference inside and outside the injector, oil density and rated flow coefficient, the new opening command from the solenoid valve is output through the adaptive control law calculation including feedforward compensation term. The system acquires information on the current temperature and type of insulating oil, and dynamically adjusts the proportional gain, integral gain, and derivative gain based on the temperature-viscosity mapping relationship or online viscosity estimation results.

8. The transformer oil sample collection pressure dynamic adjustment and control system as described in claim 7, characterized in that, A two-position three-way solenoid valve is connected to the connecting pipe between the oil inlet and the oil outlet in the oil tank. The first port of the two-position three-way solenoid valve is connected to the oil inlet, the second port of the two-position three-way solenoid valve is connected to the air filter through a one-way valve, and the third port of the two-position three-way solenoid valve is connected to the oil sampling port of the transformer oil sampling robot. When the two-position three-way solenoid valve is energized, the first port and the third port are connected, and the oil in the transformer inlet is pumped in or drawn into the main pipeline by the booster pump. At this time, the two-position three-way solenoid valve is de-energized, and the second port and the third port are connected, opening the main solenoid valve and the waste oil tank solenoid valve connected to the main pipeline. The booster pump starts the oil pumping mode, pumping the residual oil in the main pipeline into the waste oil tank. At the same time, air also enters the waste oil tank from the air filter and the one-way valve until there is no oil in the main pipeline.

9. A computer device for mounting on a transformer oil sampling robot, wherein the oil sampling port of the transformer oil sampling robot is connected to the oil outlet of an oil sampling tank, the oil sampling port is connected to multiple branch pipelines via a main pipeline, a booster pump and a main solenoid valve are connected to the main pipeline, each branch pipeline is connected to an oil sampling syringe, and each branch pipeline is connected to a corresponding slave solenoid valve and a pressure sensor, characterized in that, The computer device includes: a processor and a computer-readable storage medium; A processor, adapted to execute computer programs; A computer-readable storage medium storing a computer program, which, when executed by the processor, performs the following process: Based on the real-time acquisition of oil pressure in the syringe cavity by the pressure sensor, the difference between the oil pressure and the ambient pressure is calculated as the pressure difference between the inside and outside of the syringe. The pressure deviation between the oil pressure and the preset safety threshold is calculated, and based on the estimated instantaneous flow rate, combined with the proportional gain, integral gain, derivative gain, pressure difference inside and outside the injector, oil density and rated flow coefficient, the new opening command from the solenoid valve is output through the adaptive control law calculation including feedforward compensation term. The system acquires information on the current temperature and type of insulating oil, and dynamically adjusts the proportional gain, integral gain, and derivative gain based on the temperature-viscosity mapping relationship or online viscosity estimation results.

10. A computer-readable storage medium for mounting on a transformer oil sampling robot, wherein the oil sampling port of the transformer oil sampling robot is connected to the oil outlet of an oil sampling tank, the oil sampling port is connected to multiple branch pipelines via a main pipeline, a booster pump and a main solenoid valve are connected to the main pipeline, each branch pipeline is connected to an oil sampling syringe, and each branch pipeline is connected to a corresponding slave solenoid valve and a pressure sensor, characterized in that, The computer-readable storage medium stores a computer program adapted to be loaded by a processor and executed as follows: Based on the real-time acquisition of oil pressure in the syringe cavity by the pressure sensor, the difference between the oil pressure and the ambient pressure is calculated as the pressure difference between the inside and outside of the syringe. The pressure deviation between the oil pressure and the preset safety threshold is calculated, and based on the estimated instantaneous flow rate, combined with the proportional gain, integral gain, derivative gain, pressure difference inside and outside the injector, oil density and rated flow coefficient, the new opening command from the solenoid valve is output through the adaptive control law calculation including feedforward compensation term. The system acquires information on the current temperature and type of insulating oil, and dynamically adjusts the proportional gain, integral gain, and derivative gain based on the temperature-viscosity mapping relationship or online viscosity estimation results.

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