Hydraulic control method of hydraulic power station

Abstract

The invention relates to the technical field of hydraulic control, in particular to a hydraulic control method for a hydraulic power station, which comprises the following steps of: judging whether the hydraulic power station is in a long-time low-load operation state or not according to a production task instruction stream; if the hydraulic power station is in the long-time low-load operation state, the operation mode of the hydraulic power station is switched into a pulse oil supply and pressure inertia maintaining mode; in the pulse oil supply and pressure inertia maintaining mode, the actual working pressure requirement of a key hydraulic executing mechanism sensitive to pressure is continuously monitored, and the pressure fluctuation range of a main pipeline is adjusted; when the pressure of the main pipeline is reduced to the lower limit of the fluctuation range, the variable pump is driven to operate at high-efficiency displacement, so that the pressure of the main pipeline is increased to the upper limit of the pressure fluctuation range, and oil supply of the variable pump is stopped or the variable pump enters a zero-displacement standby state; through intelligent mode switching and optimized oil supply strategies, energy consumption and heat generation of the hydraulic power station are reduced, and the service life of hydraulic oil and elements is prolonged.

Description

[0001] This application is a divisional application of application filed on October 10, 2025, with application number 202511443174X and invention title "A hydraulic control method and system for a hydraulic power station". Technical Field

[0002] This invention relates to the field of hydraulic control technology, and in particular to a hydraulic control method for a hydraulic power station. Background Technology

[0003] In industrial production, the hydraulic power unit serves as the core drive unit. It uses an electric motor to drive a hydraulic pump, pressurizing hydraulic oil to provide hydraulic energy to actuators such as pressing equipment, clamping and positioning devices, and robotic arms. Different actuators have different requirements for system pressure and flow. Its core component is often a variable displacement piston pump driven by a frequency converter motor. The control system adjusts the pump's oil discharge through an "on-demand oil supply" strategy to maintain stable pressure in the main pipeline, theoretically improving energy efficiency.

[0004] However, in actual production, as production tasks change, the hydraulic power station often operates under low load for extended periods, causing the variable displacement piston pump to operate with extremely low oil discharge. At this time, the proportion of internal leakage to effective output flow increases dramatically, and fluid friction, throttling effect, and mechanical friction losses exacerbate heat generation, causing a significant decrease in the overall efficiency of the pump, and a large amount of input electrical energy is converted into useless heat energy.

[0005] This prolonged inefficient operation leads to a gradual accumulation and increase in hydraulic oil temperature. Hydraulic power unit oil coolers are typically designed based on heat generation under average or high loads, failing to adequately account for the unique heat patterns generated by the pump under prolonged low oil discharge and high internal leakage conditions. The cooling system cannot effectively dissipate this additional, continuously generated heat, causing the hydraulic oil temperature to rise continuously, exceeding the recommended operating temperature range. This increased hydraulic oil temperature triggers a series of chain reactions, such as decreased oil viscosity leading to further internal leakage in components, creating a vicious cycle; simultaneously, deteriorated lubrication accelerates component wear, high temperatures accelerate seal aging leading to leaks, reduced precision control component accuracy, decreased system rigidity and response speed, and accelerated oil oxidation and deterioration, increasing the risk of failure.

[0006] While existing hydraulic control methods can adjust the pump's oil discharge based on pressure feedback, they primarily focus on instantaneous pressure stability and energy conservation, failing to adequately consider the heat accumulation caused by the nonlinear characteristics of the pump's efficiency curve under prolonged low-load operation. The control system lacks real-time sensing and prediction capabilities of the system's thermal state, and also lacks a mechanism to proactively adjust pump operating strategies or implement other thermal management measures when oil temperature abnormally rises. It merely passively maintains pressure without actively managing the system's thermal balance, leading to the aforementioned performance degradation and failure risks.

[0007] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0008] The purpose of this invention is to address the shortcomings of existing technologies by proposing a hydraulic control method for a hydraulic power station.

[0009] In a first aspect, the present invention provides a hydraulic control method for a hydraulic power station, the method comprising the following steps: Based on the production task instruction flow, determine whether the hydraulic power station is in a long-term low-load operation state; If the hydraulic power unit is in a long-term low-load operation state, switch the operating mode of the hydraulic power unit to pulse oil supply and pressure inertia maintenance mode. In the pulse oil supply and pressure inertia maintenance mode, the actual working pressure requirements of the pressure-sensitive key hydraulic actuators are continuously monitored, and the pressure fluctuation range of the main pipeline is adjusted according to the actual working pressure requirements. When the pressure in the main pipeline drops to the lower limit of the fluctuation range, the variable pump is driven to operate at high efficiency to raise the pressure in the main pipeline to the upper limit of the pressure fluctuation range, and the oil supply of the variable pump is stopped or it is put into a zero-displacement standby state. In pulse oil supply and pressure inertia maintenance mode, the action commands of high-priority hydraulic actuators are continuously monitored. When the high-priority action command is detected, the pulse oil supply and pressure inertia maintenance mode is immediately interrupted, and the variable pump is driven to operate at maximum displacement.

[0010] Secondly, a hydraulic control system for a hydraulic power station is provided, the system comprising: The judgment module is used to determine whether the hydraulic power station is in a long-term low-load operation state based on the production task instruction flow; The mode switching module is used to switch the operating mode of the hydraulic power station to pulse oil supply and pressure inertia maintenance mode if the hydraulic power station is in a long-term low-load operation state. The lower pressure limit adjustment module is used to continuously monitor the actual working pressure requirements of the pressure-sensitive key hydraulic actuators in the pulse oil supply and pressure inertia maintenance mode, and adjust the pressure fluctuation range of the main pipeline according to the actual working pressure requirements. The pulse oil supply module is used to drive the variable pump to operate at high efficiency when the main pipeline pressure drops to the lower limit of the fluctuation range, so that the main pipeline pressure rises to the upper limit of the pressure fluctuation range, and then stops the oil supply of the variable pump or puts it into a zero displacement standby state. The high-priority response module is used to continuously monitor the action commands of the high-priority hydraulic actuator in pulse oil supply and pressure inertia maintenance mode. When the high-priority action command is detected, the pulse oil supply and pressure inertia maintenance mode is immediately interrupted, and the variable pump is driven to operate at maximum displacement.

[0011] Compared with the prior art, the present invention has the following beneficial effects: By determining whether the hydraulic power station is operating at low load for an extended period based on production task command flow, and switching the operating mode to pulse oil supply and pressure inertia maintenance mode in this state, the system effectively solves the problems of low pump efficiency and heat accumulation leading to increased oil temperature in existing hydraulic power stations under prolonged low load operation. In pulse oil supply and pressure inertia maintenance mode, the system no longer maintains continuous high pressure, but allows the main pipeline pressure to fluctuate within a certain range. Only when the pressure drops to the lower limit is the variable pump driven to operate at high displacement to restore the pressure to the upper limit, after which oil supply stops or enters zero-displacement standby. This intermittent and efficient oil supply method significantly reduces the ineffective power consumption and internal leakage heat generation of the variable pump under low load, thereby lowering the hydraulic oil temperature. Simultaneously, this method continuously monitors the actual working pressure requirements of pressure-sensitive critical hydraulic actuators and adjusts the main pipeline pressure fluctuation range accordingly, ensuring the accuracy and reliability of critical task execution. Furthermore, when a high-priority hydraulic actuator's action command is detected, the system can immediately interrupt the pulse oil supply mode and drive the variable pump to operate at maximum displacement, ensuring the system's rapid response capability to emergency or high-load demands. In summary, the method of this application effectively reduces the energy consumption and heat generation of the hydraulic power station by intelligent mode switching and optimized oil supply strategy, extends the service life of hydraulic oil and components, improves the overall efficiency, stability and reliability of the system, and overcomes the shortcomings of the prior art in passively maintaining pressure while ignoring thermal balance management. Attached Figure Description

[0012] Figure 1 This is a flowchart of the method of the present invention.

[0013] Figure 2 This is a schematic diagram of the system structure of the present invention.

[0014] In the diagram: 201, Judgment Module; 202, Mode Switching Module; 203, Pressure Lower Limit Adjustment Module; 204, Pulse Oil Supply Module; 205, High Priority Response Module. Detailed Implementation

[0015] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0016] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0017] The hydraulic control method proposed in this application aims to optimize the operating efficiency and stability of a hydraulic power station under different load conditions. "Prolonged low-load operation" refers to a state where the average power output of the hydraulic power station is significantly lower than its rated power, and this state persists for a preset period, such as several consecutive hours or a shift. This state typically occurs during light-load operations on the production line, equipment standby, or maintenance. The "pulse oil supply and pressure inertia maintenance mode" is an energy-saving operating strategy. Its core idea is to intermittently supply oil to the main pipeline to maintain the main pipeline pressure within a certain fluctuation range, rather than continuously supplying constant pressure. In this mode, the variable pump only starts supplying oil when the main pipeline pressure is below the set lower limit, and stops or enters a zero-displacement state after reaching the upper limit, thereby reducing pump operating time and lowering energy consumption and heat generation.

[0018] like Figure 1 The hydraulic control method of a hydraulic power station shown includes the following steps: S101. Based on the production task instruction flow, determine whether the hydraulic power station is in a long-term low-load operation state; It should be noted that in the hydraulic control method of the hydraulic power station, the first step is to determine whether the hydraulic power station is in a prolonged low-load operation state based on the production task instruction flow. One approach is to analyze the task instructions issued by the production management system. For example, if the instructions indicate that the current production line is mainly performing light-load assembly or inspection tasks for a relatively long period, it can be determined as low-load operation. Another approach is to monitor the output power or flow rate of the hydraulic power station in real time and compare it with a preset low-load threshold. For example, a threshold can be set; when the average output power of the hydraulic power station is continuously below the threshold for a certain period, it is determined to be a prolonged low-load operation state.

[0019] S102. If the hydraulic power station is in a long-term low-load operation state, the operation mode of the hydraulic power station shall be switched to pulse oil supply and pressure inertia maintenance mode. It should be noted that in the above step, this switching can be achieved by the control system sending a mode switching command to the variable pump controller. For example, when the judgment module issues a low-load operation signal, the mode switching module receives the signal and automatically adjusts the control parameters of the variable pump, changing it from continuous fuel supply mode to pulse fuel supply mode.

[0020] S103. In pulse oil supply and pressure inertia maintenance mode, continuously monitor the actual working pressure requirements of key hydraulic actuators that are sensitive to pressure, and adjust the pressure fluctuation range of the main pipeline according to the actual working pressure requirements. It should be noted that this step can be achieved, for example, by installing pressure sensors at the inlet or working chamber of critical hydraulic actuators to acquire their operating pressure data in real time. This data is fed back to the lower pressure limit adjustment module, which dynamically adjusts the upper and lower limits of the main pipeline pressure fluctuation range based on this real-time pressure data and a preset pressure demand curve or algorithm. For example, if it is detected that a critical actuator requires a higher instantaneous pressure to complete its action, the lower limit of the main pipeline pressure fluctuation range can be appropriately increased to ensure its normal operation.

[0021] S104. When the pressure in the main pipeline drops to the lower limit of the fluctuation range, drive the variable pump to operate at high efficiency to raise the pressure in the main pipeline to the upper limit of the pressure fluctuation range, stop the oil supply of the variable pump or put it into a zero-displacement standby state. It should be noted that in this step, for example, when the main pipeline pressure sensor detects that the pressure is lower than the preset lower limit, the pulse fuel supply module will immediately send a start command to the variable pump, causing it to operate at a preset high-efficiency displacement (e.g., the pump's maximum displacement or close to its maximum displacement) to quickly raise the main pipeline pressure to the upper limit. Once the pressure reaches the upper limit, the variable pump will immediately stop fuel supply or enter a zero-displacement standby state to reduce unnecessary energy consumption.

[0022] S105. In pulse oil supply and pressure inertia maintenance mode, continuously monitor the action commands of high-priority hydraulic actuators. When a high-priority action command is detected, immediately interrupt the pulse oil supply and pressure inertia maintenance mode and drive the variable pump to operate at maximum displacement.

[0023] It should be noted that in this step, for example, the high-priority response module will continuously receive instructions from the production control system or operators, such as emergency stop, safety protection actions, or start instructions for critical process steps. Once such a high-priority instruction is detected, the system will immediately exit the pulse oil supply mode and force the variable pump to operate at maximum displacement to ensure that high-priority actions can be completed quickly and reliably, thus guaranteeing production safety and efficiency.

[0024] The hydraulic control method for the hydraulic power station proposed in this application effectively solves the problems of low efficiency and heat accumulation in traditional hydraulic power stations under long-term low-load operation by introducing a "pulse oil supply and pressure inertia maintenance mode." Traditional methods mainly focus on instantaneous pressure stability and energy saving, but fail to fully consider the special heat generation patterns of the pump under long-term low-displacement and high internal leakage conditions. In contrast, the method in this application can intelligently determine whether the hydraulic power station is in a long-term low-load operation state based on the production task command flow, and switch to pulse oil supply mode in this state. In this mode, the variable pump only starts when the main pipeline pressure drops to the lower limit of the fluctuation range, and stops or enters zero-displacement standby after reaching the upper limit, significantly reducing the pump's operating time and thus greatly reducing the pump's internal losses and heat generation.

[0025] Furthermore, the method of this application can continuously monitor the actual working pressure requirements of pressure-sensitive critical hydraulic actuators and dynamically adjust the pressure fluctuation range of the main pipeline accordingly, ensuring that the performance of critical actuators is not affected while saving energy. Simultaneously, the introduction of a high-priority response mechanism ensures that the system can respond quickly under emergency or critical task requirements, driving the variable pump to operate at maximum displacement, ensuring production safety and efficiency. This proactive management system's thermal balance and response priority strategy enables the hydraulic power station to achieve a better energy efficiency ratio and higher operational reliability under different operating conditions, effectively avoiding a series of problems caused by increased oil temperature, such as decreased oil viscosity, accelerated component wear, aging of seals, and decreased control accuracy, which are common in traditional methods. This significantly improves the overall performance and service life of the hydraulic system.

[0026] As one embodiment of the present invention, in the pulse oil supply and pressure inertia maintenance mode, the step of continuously monitoring the actual working pressure demand of the pressure-sensitive key hydraulic actuator and adjusting the pressure fluctuation range of the main pipeline according to the actual working pressure demand includes: In pulse oil supply and pressure inertia maintenance mode, the actual working pressure requirements of pressure-sensitive key hydraulic actuators are continuously monitored. It should be noted that the above step refers to collecting real-time operating pressure data through pressure sensors installed in the hydraulic circuit of critical hydraulic actuators. This data reflects the instantaneous pressure required by the actuators when performing specific tasks.

[0027] After the variable pump stops supplying oil, monitor the time required for the main pipeline pressure to drop from the initial pressure to the termination pressure; It should be noted that the starting pressure and the ending pressure can be preset to specific pressure thresholds. For example, the starting pressure can be the upper limit of the pressure fluctuation range of the main pipeline, while the ending pressure can be a value slightly lower than the upper limit. The purpose is to obtain the natural decay characteristics of the main pipeline pressure under the condition of no pump oil supply.

[0028] By comparing the required time with the preset baseline time, the change in the main pipeline pressure decay rate can be determined; It should be noted that the preset reference time is based on the standard time required for the main pipeline pressure to drop from the initial pressure to the final pressure under healthy operating conditions of the hydraulic power station. Its purpose is to provide a reference benchmark in order to quantify the degree of deviation of the current pressure decay rate.

[0029] Assess the internal leakage trends of key hydraulic actuators based on changes in pressure decay rate; It should be noted that, for example, if the actual monitored pressure drop time is significantly shorter than the reference time, it indicates an accelerated pressure decay rate, which is usually a direct reflection of increased internal leakage in critical hydraulic actuators.

[0030] Adjust the lower limit of the main pipeline pressure fluctuation range according to the actual working pressure requirements and internal leakage trends to compensate for the loss of effective output force of key hydraulic actuators.

[0031] It should be noted that the lower limit of the pressure fluctuation range of the main pipeline is adjusted according to the actual working pressure requirements and the internal leakage trend. The purpose is to ensure that even if there is internal leakage, the key hydraulic actuator can still obtain sufficient effective pressure to compensate for the loss of its effective output force.

[0032] This application's solution dynamically assesses the internal leakage trend of critical hydraulic actuators by introducing monitoring and analysis of the main pipeline pressure decay rate. When the variable pump stops supplying oil, the rate of pressure drop in the main pipeline is not only affected by the system load but also directly reflects the internal leakage status of the hydraulic actuator. By comparing the actual monitored pressure decay time with a preset reference time, the change in the pressure decay rate can be accurately quantified. This change, especially the acceleration of the decay rate, directly indicates an increase in internal leakage in the critical hydraulic actuator. Once the internal leakage trend is assessed, the system can intelligently adjust the lower limit of the main pipeline pressure fluctuation range based on the actual working pressure requirements of the critical hydraulic actuator. Specifically, if an increase in internal leakage is detected, the system will appropriately raise the lower limit of the main pipeline pressure fluctuation range to compensate for the resulting loss of effective output force. This means that in pulse oil supply mode, when the variable pump restarts oil supply, it will raise the main pipeline pressure to a higher lower limit, thereby ensuring that even in the presence of internal leakage, the critical hydraulic actuator can obtain sufficient effective pressure to meet its required output force.

[0033] Through the aforementioned technical solutions, the hydraulic control method can dynamically adapt to the internal wear and leakage conditions of critical hydraulic actuators. By monitoring the pressure decay rate in real time and assessing internal leakage trends, the system can accurately identify and quantify the loss of effective output force caused by internal leakage. Therefore, by intelligently adjusting the lower limit of the main pipeline pressure fluctuation range, the system can effectively compensate for this loss, ensuring that critical hydraulic actuators maintain the required output force throughout the entire operating cycle, thereby significantly improving the operational accuracy and reliability of the hydraulic system. Furthermore, this adaptive pressure control mechanism helps extend the service life of critical hydraulic components, reduces unplanned downtime, and thus improves production efficiency and reduces maintenance costs.

[0034] In some preferred embodiments, a specific example is illustrated below. Assume that in an injection molding machine hydraulic system, the clamping cylinder is identified as a pressure-sensitive critical hydraulic actuator. When the injection molding machine is operating at low load for an extended period, the system switches to a pulsed injection and pressure inertia maintenance mode. In this mode, after the variable pump completes one injection and stops, the system begins monitoring the time required for the main pipeline pressure to drop from 20 MPa to 18 MPa. Using a high-precision pressure sensor and timer, the system records this pressure drop as taking 4.5 seconds. The system internally stores a baseline decay time for the clamping cylinder in a healthy state, for example, 5.0 seconds. By comparison, the system finds that the actual decay time (4.5 seconds) is shorter than the baseline time (5.0 seconds), indicating an accelerated rate of pressure decay in the main pipeline. Based on this, the system assesses an increasing trend of internal leakage in the clamping cylinder. To compensate for the loss of clamping force due to internal leakage, the system dynamically adjusts the lower limit of the main pipeline pressure fluctuation range based on the current actual operating pressure requirement of the clamping cylinder (e.g., maintaining an effective clamping force of 15 MPa) and the assessed internal leakage trend. If the original lower limit was set to 14MPa, the system may adjust it to 14.5MPa. This means that during the next pulse oil supply, the variable pump will raise the main pipeline pressure to the upper limit and restart when the pressure drops to 14.5MPa, thereby ensuring that the clamping cylinder can continuously obtain sufficient effective pressure even in the presence of internal leakage, to guarantee a stable clamping force and avoid product quality problems.

[0035] As one embodiment of the present invention, prior to the step of monitoring the time required for the main pipeline pressure to decrease from the initial pressure to the final pressure, the method includes: Identify currently active critical hydraulic actuators and isolate the hydraulic circuits of non-critical hydraulic actuators during time monitoring; It's important to note that identifying currently active critical hydraulic actuators means that before conducting an internal leakage trend assessment, the system needs to clearly identify the hydraulic actuators currently performing tasks or requiring high pressure accuracy. This is because hydraulic power units typically serve multiple actuators, and internal leakage assessments should focus on the critical components that have the greatest impact on system performance under the current operating conditions. Identification ensures that subsequent isolation and monitoring operations are highly targeted, avoiding unnecessary resource consumption. During time-based monitoring, isolating the hydraulic circuits of non-critical hydraulic actuators can be understood as disconnecting other non-critical hydraulic circuits that might affect the pressure decay rate measurement from the main pipeline while monitoring the pressure decay in the main pipeline to assess the internal leakage of critical hydraulic actuators. The purpose is to eliminate interference from leaks, volume changes, or residual pressure in non-critical circuits on the pressure decay process in the main pipeline, thereby ensuring that the monitored pressure decay rate more accurately reflects the internal leakage characteristics of the currently active critical hydraulic actuators themselves. In practical applications, this can be achieved by controlling appropriate valves, such as closing the supply branch valves of non-critical hydraulic actuators and / or isolation valves on the common return path.

[0036] The steps for assessing the internal leakage trends of critical hydraulic actuators based on changes in pressure decay rate include: Based on the comparison between the monitored time and the preset baseline time, and the change in the pressure decay rate of the currently active critical hydraulic actuators in the isolated state, the internal leakage trend of the currently active critical hydraulic actuators is assessed and identified.

[0037] It should be noted that the above step refers to a precise assessment of the pressure decay characteristics of the critical hydraulic actuator, assuming that interference from non-critical hydraulic actuator circuits has been eliminated. By comparing the pressure decay data obtained in isolation with a preset reference time, the degree of internal leakage and its changing trend of the critical hydraulic actuator can be determined more accurately. This assessment method can effectively distinguish between leakage within the critical hydraulic actuator itself and leakage or pressure fluctuations in other parts of the system, thus providing a more reliable basis for subsequent adjustments to the main pipeline pressure fluctuation range.

[0038] The proposed solution, when assessing the internal leakage trends of critical hydraulic actuators, first identifies currently active critical hydraulic actuators, ensuring the relevance of the assessment. More importantly, by isolating the hydraulic circuits of non-critical hydraulic actuators during pressure decay time monitoring, it effectively eliminates interference from additional leakage paths, volumetric effects, or residual pressure introduced by these non-critical circuits on the main pipeline pressure decay rate. It is precisely this precise isolation that allows the monitored main pipeline pressure decay rate to more purely and accurately reflect the internal leakage status of the currently active critical hydraulic actuators themselves. Therefore, based on the pressure decay rate changes obtained under isolation conditions, combined with comparisons to preset baseline times, a more accurate assessment of the internal leakage trends of critical hydraulic actuators can be made, thus providing more reliable and accurate data support for subsequent adjustments to the lower limit of the main pipeline pressure fluctuation range.

[0039] Through the above technical solution, this application can significantly improve the accuracy of assessing the internal leakage trend of critical hydraulic actuators. Compared with solutions without isolation, this application eliminates interference from non-critical hydraulic actuator circuits, allowing the measured pressure decay rate to more accurately reflect the actual leakage status of critical hydraulic actuators. This precise leakage assessment enables more accurate compensation for the effective output force loss of critical hydraulic actuators by adjusting the lower limit of the main pipeline pressure fluctuation range. This, in turn, maximizes the duration of pulse oil supply and pressure inertia maintenance modes while ensuring system performance, further reducing the energy consumption of the hydraulic power station. Furthermore, accurate leakage trend assessment helps to detect potential failures of critical components early, improving equipment reliability and maintenance efficiency.

[0040] As one embodiment of the present invention, the step of identifying currently active key hydraulic actuators includes: Acquire production task instructions and status feedback information from key hydraulic actuators; Based on production task instructions and status feedback information from each key hydraulic actuator, identify the hydraulic actuators currently in operation as active hydraulic actuators.

[0041] Specifically, production task instruction information may include the currently executing production process, the type and quantity of hydraulic actuators required, and the expected work cycle. This information is typically provided by a higher-level control system or production management system. Status feedback information from each key hydraulic actuator may include its current operating status (e.g., whether it is in motion, its position, speed, pressure, etc.), fault alarm information, and maintenance status. This information is usually collected in real time through sensors, encoders, or feedback units integrated into the actuators. By comprehensively analyzing this information, it is possible to accurately determine which key hydraulic actuators are currently participating in production tasks or are about to be activated to perform specific operations, thus identifying them as active hydraulic actuators.

[0042] The solution proposed in this application can accurately identify critical hydraulic actuators that are currently operating or about to operate by acquiring production task instruction information and status feedback information from each key hydraulic actuator. This identification mechanism ensures that when monitoring the time required for the main pipeline pressure to drop from the initial pressure to the final pressure, attention can be focused on the active actuators that truly affect the pressure decay rate. This avoids measurement errors introduced by the uncertainty of the loop status of inactive actuators, thus laying the foundation for accurately assessing the internal leakage trends of critical hydraulic actuators.

[0043] As one embodiment of the present invention, the step of isolating the hydraulic circuits of other non-critical hydraulic actuators during time monitoring includes: During time monitoring, identify non-critical hydraulic actuators that share supply or return paths with currently active critical hydraulic actuators; It should be noted that this step specifically refers to analyzing the piping topology and valve configuration of the hydraulic system to determine which non-critical hydraulic actuators' supply or return paths may have hydraulic connections or mutual influences with the main pipelines of critical hydraulic actuators currently undergoing pressure decay monitoring. This typically involves consulting hydraulic system diagrams or making logical judgments using preset system configuration data.

[0044] Coordinate the control of the oil supply branch valves and / or isolation valves on the common return path of non-critical hydraulic actuators to block the connection between non-critical hydraulic actuators and the main pipeline, thereby isolating the hydraulic circuit of non-critical hydraulic actuators. It should be noted that this step specifically refers to, after identifying a potential source of interference, sending a command through the control system to the corresponding solenoid valve, proportional valve, or other type of isolation valve to close or switch to the blocking position. This operation aims to physically disconnect the hydraulic connection between the non-critical hydraulic actuator and the main pipeline, thereby preventing changes in its internal pressure or flow rate from interfering with the pressure decay process of the main pipeline.

[0045] After the blocking operation is completed, monitor the residual pressure or flow in the non-critical hydraulic actuator circuits; It should be noted that the purpose of this step is to verify the effectiveness of the isolation operation. Specifically, pressure or flow sensors can be installed in the isolated non-critical hydraulic actuator circuit to detect in real time whether there is residual pressure that has not been completely eliminated or continuous hydraulic oil flow.

[0046] When the residual pressure or flow exceeds the preset threshold, auxiliary pressure relief or secondary isolation operations are performed to eliminate the interference of residual pressure or flow on the pressure decay rate of the main pipeline.

[0047] It should be noted that this step implies that if the initial isolation fails to completely eliminate the interference, the system will take further measures. Auxiliary pressure relief operations may involve slowly releasing residual pressure in the circuit by opening a pressure relief valve or controlling specific valves. Secondary isolation operations may involve closing additional valves or re-executing the isolation command to ensure a complete disconnection.

[0048] The proposed solution proactively identifies and isolates non-critical hydraulic actuators that may interfere with the main pipeline pressure decay rate during time monitoring, further monitors the isolation effect, and performs auxiliary pressure relief or secondary isolation operations when necessary, thereby ensuring the purity of the main pipeline pressure decay process. As a result, the main pipeline pressure decay will primarily reflect the internal leakage characteristics of the monitored critical hydraulic actuators, avoiding interference from residual pressure or flow in other circuits on the measurement results, and significantly improving the accuracy of pressure decay rate assessment.

[0049] As one embodiment of the present invention, the steps for performing auxiliary depressurization or secondary isolation operations include: Continuously monitor the residual pressure or flow in non-critical hydraulic actuator circuits; It should be noted that the above step refers to acquiring the pressure or flow value in the non-critical hydraulic actuator circuit in real time by installing a pressure sensor or flow sensor in that circuit. The purpose is to provide real-time feedback data for subsequent auxiliary pressure relief or secondary isolation operations, ensuring the accuracy and effectiveness of the operation. Residual pressure or flow can be understood as the pressure or flow that still exists in the non-critical hydraulic actuator circuit after the isolation valve is closed, due to factors such as the compressibility of the hydraulic oil, the volumetric effect of the circuit, or minor leakage of the valve itself, and that may interfere with the measurement of the main pipeline pressure decay rate.

[0050] Adjust the intensity or duration of auxiliary pressure relief or secondary isolation operations based on the monitored residual pressure or flow rate; It should be noted that the above step means that the auxiliary pressure relief or secondary isolation operation is not performed with fixed parameters, but is dynamically adjusted according to the real-time monitored residual pressure or flow rate. For example, when the residual pressure or flow rate is high, the opening degree of the pressure relief valve can be increased or the pressure relief time can be extended to improve pressure relief efficiency; when the residual pressure or flow rate is low, the pressure relief intensity can be reduced or the pressure relief time can be shortened to avoid excessive pressure relief and energy waste. Intensity can refer to the opening degree of the pressure relief valve, the speed of the pressure relief pump, or the diameter of the pressure relief channel, while duration refers to the duration of the pressure relief operation.

[0051] Continue to perform the adjusted auxiliary pressure relief or secondary isolation operations until the residual pressure or flow rate of the non-critical hydraulic actuator circuit drops below the preset threshold.

[0052] It should be noted that the above step implies that the auxiliary pressure relief or secondary isolation operation is an iterative or continuous process, not a one-time operation. The system will continuously adjust operating parameters based on real-time feedback until the residual pressure or flow rate reaches an acceptable level that does not interfere with the measurement of the main pipeline pressure decay rate. The preset threshold is a pre-set benchmark value used to determine whether the residual pressure or flow rate has been sufficiently eliminated.

[0053] This application's solution introduces a continuous monitoring mechanism for residual pressure or flow in non-critical hydraulic actuator circuits, and dynamically adjusts the intensity or duration of auxiliary pressure relief or secondary isolation operations based on this monitoring result, thus forming a closed-loop control system. It is precisely this feedback adjustment mechanism that allows auxiliary pressure relief or secondary isolation operations to precisely target residual pressure or flow, avoiding the shortcomings that may arise from fixed-parameter operation. When residual pressure or flow is high, the system can increase the pressure relief intensity to quickly eliminate interference; when residual pressure or flow approaches a threshold, the system can finely adjust to avoid excessive pressure relief, ensuring optimal isolation with minimal energy consumption. This adaptive control method ensures complete isolation of non-critical hydraulic actuator circuits, providing a clean testing environment for accurate measurement of the subsequent main pipeline pressure decay rate.

[0054] The above technical solutions ensure that residual pressure or flow in non-critical hydraulic actuator circuits is completely and efficiently eliminated, significantly improving the accuracy of main pipeline pressure decay rate measurement. This precise isolation operation makes the assessment of internal leakage trends in critical hydraulic actuators more reliable, thereby enabling more accurate adjustment of the lower limit of main pipeline pressure fluctuation range and effectively compensating for the loss of effective output force in critical hydraulic actuators. Furthermore, by dynamically adjusting the intensity and duration of auxiliary pressure relief or secondary isolation operations, energy consumption can be optimized, unnecessary energy waste avoided, and the overall operating efficiency of the hydraulic power unit improved.

[0055] As one embodiment of the present invention, the process of setting the preset threshold includes: Obtain the current operating parameters of the hydraulic power unit; It should be noted that obtaining the current operating parameters of the hydraulic power unit refers to acquiring key parameters affecting the performance of the hydraulic system in real time through sensors or control system interfaces. These parameters include hydraulic oil temperature, ambient temperature, main system pipeline pressure, and the operating frequency or displacement of the hydraulic pump. These parameters provide basic data for the subsequent preliminary determination of preset thresholds, as they directly affect the physical properties of the hydraulic oil and the dynamic response of the circuit.

[0056] Based on the current operating parameters, the preset threshold is initially determined; It should be noted that this step can be understood as using a pre-established mathematical model, empirical formula, or lookup table to make an initial estimate of the preset threshold based on the currently acquired operating parameters. For example, when the hydraulic oil temperature is high, its viscosity will decrease, and the residual pressure may decay faster, so the initially determined threshold may need to be adjusted lower accordingly.

[0057] Under preset calibration conditions, monitor the residual pressure or flow decay process of non-critical hydraulic actuator circuits; It should be noted that the above step refers to actively triggering the isolation of non-critical hydraulic actuator circuits under controlled and known specific operating conditions, and accurately recording the changes in residual pressure or flow over time. For example, an isolation operation can be performed when the system is under no-load conditions, the hydraulic oil temperature is stable, or a specific main pipeline pressure is applied, and high-precision sensors are used to continuously monitor pressure or flow changes in the circuit. The purpose of this step is to obtain data on the actual attenuation behavior of the system under specific conditions, serving as empirical evidence for subsequent updates to the baseline attenuation characteristics.

[0058] Update the baseline decay characteristics of non-critical hydraulic actuator circuits based on monitoring results of residual pressure or flow decay processes. It should be noted that the above step refers to comparing and analyzing the actual attenuation data monitored under calibration conditions with the existing benchmark attenuation model or curve stored internally in the system. Through methods such as data fitting, parameter optimization, or machine learning, the benchmark attenuation characteristics are corrected and updated to more accurately reflect the actual state of the current hydraulic system, including performance changes caused by factors such as component wear and increased leakage.

[0059] Based on the baseline attenuation characteristics, the initially determined preset threshold is compensated and adjusted.

[0060] It should be noted that this step refers to a fine-tuning of the preset threshold based on the initially determined threshold and the updated baseline attenuation characteristics. For example, if the updated baseline attenuation characteristics show that the residual pressure in the circuit attenuates faster than expected under the current operating parameters, the preset threshold may need to be appropriately lowered to avoid misjudging the presence of residual pressure; conversely, if the attenuation rate slows down, the threshold may need to be increased. This compensatory adjustment ensures that the preset threshold can dynamically adapt to changes in the internal state of the hydraulic system, improving the accuracy and reliability of the judgment.

[0061] This application's solution addresses the inaccuracy issues that may arise from traditional fixed thresholds under complex and variable operating conditions by introducing a dynamic preset threshold setting process. Specifically, it first acquires the current operating parameters of the hydraulic power station, allowing the initial threshold determination to consider the current system's operating environment, such as the influence of oil temperature on hydraulic oil viscosity, thus avoiding initial deviations caused by environmental changes. Furthermore, by monitoring the residual pressure or flow decay process of non-critical hydraulic actuator circuits under preset calibration conditions, this application obtains real decay data of the system under specific conditions, providing empirical evidence for subsequent accurate evaluation. Therefore, the baseline decay characteristics of non-critical hydraulic actuator circuits are updated based on the monitoring results, enabling the system to learn and adapt to long-term changes such as aging, wear, or internal leakage, ensuring the real-time nature and accuracy of the baseline. Finally, the initially determined preset threshold is compensated and adjusted based on the updated baseline decay characteristics, ensuring that the threshold not only considers the current operating parameters but also incorporates the system's own dynamic decay characteristics, thereby ensuring more accurate and reliable judgment of residual pressure or flow when isolating non-critical hydraulic actuator circuits. Through the above technical solution, this application can achieve dynamic and adaptive setting of preset threshold values ​​for residual pressure or flow in non-critical hydraulic actuator circuits.

[0062] As one embodiment of the present invention, the step of updating the reference attenuation characteristics of a non-critical hydraulic actuator circuit includes: Obtain monitoring results of residual pressure or flow decay process; It should be noted that the above step refers to continuously sampling and recording the changes in residual pressure or flow rate over time in the isolated state of non-critical hydraulic actuator circuits using pressure or flow sensors under preset calibration conditions. These monitoring results are typically presented in the form of time-series data, reflecting the natural decay process of the circuit under the influence of no external oil supply or return.

[0063] Based on the preset attenuation model, the monitoring results are processed. It should be noted that the above step can be understood as fitting or comparing the acquired actual attenuation data with a predefined mathematical model. This predefined attenuation model aims to describe the attenuation law of pressure or flow in the hydraulic circuit; for example, it could be an exponential attenuation model, taking into account the compressibility characteristics of the hydraulic oil and the damping characteristics of the circuit. The data processing may include preprocessing steps such as data cleaning, smoothing, and normalization, as well as substituting the monitored data into the model for calculation or fitting.

[0064] Based on the data processing results, determine the parameters of the attenuation model; It should be noted that the above step refers to deriving the model parameters that best represent the actual decay process from the data processing results through optimization algorithms (such as least squares method, gradient descent method, etc.) or statistical analysis methods. These parameters are specific values ​​of the decay model, which quantify the inherent characteristics of the loop, such as decay constant, initial pressure, or flow rate.

[0065] The determined model parameters are used as the baseline attenuation characteristics for non-critical hydraulic actuator circuits.

[0066] It should be noted that this step means that the model parameters, which have been fitted and determined by data, are established as standard descriptions of the degradation behavior of this specific non-critical hydraulic actuator circuit under ideal or healthy conditions. These benchmark characteristics will serve as a reference for subsequent assessments of circuit condition and identification of anomalies or leakage trends.

[0067] This application's solution establishes a quantitative and accurate baseline attenuation characteristic for non-critical hydraulic actuator circuits by introducing a pre-defined attenuation model and determining its parameters based on actual monitoring data. Under pre-defined calibration conditions, when a non-critical hydraulic actuator circuit is isolated, the attenuation process of its residual pressure or flow is mainly affected by factors such as circuit leakage, oil compressibility, and pipeline damping. By acquiring the monitoring results of this attenuation process and fitting them to an attenuation model that reflects these physical phenomena, the inherent attenuation parameters of the circuit can be effectively extracted. These parameters not only accurately describe the current attenuation behavior of the circuit but also have better robustness and interpretability because they are based on a model. Thus, the determined model parameters become the "health fingerprint" of the circuit, providing a reliable benchmark for the attenuation behavior monitored in actual operation, thereby enabling a more accurate assessment of internal leakage trends and providing a scientific basis for adjusting the compensation of pre-defined thresholds.

[0068] Through the above technical solution, this application overcomes the limitations of traditional methods that rely solely on experience or simple time comparisons to evaluate loop attenuation characteristics. By introducing a model-based parameter determination method, the attenuation patterns of non-critical hydraulic actuator loops can be captured more accurately and comprehensively, especially under complex operating conditions, effectively distinguishing between normal attenuation and accelerated attenuation caused by abnormal leakage. This makes the assessment of internal leakage trends in critical hydraulic actuators more accurate, thereby enabling more precise adjustment of the lower limit of the main pipeline pressure fluctuation range to effectively compensate for the output force loss of critical hydraulic actuators and improve the operating efficiency and reliability of the hydraulic system.

[0069] As one embodiment of the present invention, the process of constructing the preset attenuation model includes: The attenuation model was determined based on the compressibility characteristics of hydraulic oil; It should be noted that the attenuation model aims to accurately describe the changes in pressure or flow rate over time in a hydraulic circuit. This step refers to fully considering the physical property that hydraulic oil undergoes minute volume changes under pressure when constructing the model. This compressibility causes the pressure to exhibit a certain degree of elastic behavior as it propagates and attenuates in the circuit.

[0070] The attenuation model is determined based on the damping characteristics of the hydraulic circuit; It should be noted that the above step refers to incorporating various energy dissipation factors present in the hydraulic circuit into the model, such as pipe friction, valve resistance, and internal leakage of hydraulic components. These damping effects cause the pressure or flow rate decay process to exhibit dissipative characteristics.

[0071] The attenuation model is determined to be in the form of exponential attenuation, in order to combine the compression and damping characteristics to construct the attenuation model.

[0072] It should be noted that the exponential decay model was chosen to organically combine the compression characteristics of hydraulic oil and the damping characteristics of the hydraulic circuit. The exponential decay model can well simulate the process of energy or signal gradually weakening over time in many physical systems. Its mathematical form is simple and can effectively reflect the actual dynamics of pressure decay in hydraulic systems.

[0073] This application's solution uses the compressibility characteristics of hydraulic oil and the damping characteristics of the hydraulic circuit as the basis for constructing a preset attenuation model, and employs an exponential attenuation form to more accurately simulate the actual attenuation process of pressure or flow in the hydraulic circuit. The compressibility characteristics of hydraulic oil determine the system's ability to store and release energy when pressure changes, while the damping characteristics of the hydraulic circuit reflect the rate of energy dissipation. Combining these two and expressing them exponentially allows the model to capture the typical behavior of pressure rapidly decreasing from a high point, followed by a gradual slowdown in the attenuation rate. Therefore, when monitoring the residual pressure or flow attenuation process of non-critical hydraulic actuator circuits, data processing based on this model can more accurately fit the actual data, thereby accurately determining the parameters of the attenuation model and updating the baseline attenuation characteristics of non-critical hydraulic actuator circuits.

[0074] Through the aforementioned technical solution, the constructed preset attenuation model can more realistically reflect the physical characteristics of the hydraulic system, improving the accuracy of data processing for residual pressure or flow attenuation processes. This makes the subsequent determination of attenuation model parameters and the updating of the baseline attenuation characteristics of non-critical hydraulic actuator circuits more reliable. Ultimately, this helps to more accurately assess the internal leakage trend of critical hydraulic actuators and more precisely adjust the lower limit of the main pipeline pressure fluctuation range, thereby effectively compensating for the effective output force loss of critical hydraulic actuators and improving the operating efficiency and control accuracy of the hydraulic power station.

[0075] like Figure 2 The hydraulic control system of the hydraulic power station shown includes: The judgment module 201 is used to determine whether the hydraulic power station is in a long-term low-load operation state based on the production task instruction flow. The mode switching module 202 is used to switch the operating mode of the hydraulic power station to pulse oil supply and pressure inertia maintenance mode if the hydraulic power station is in a long-term low-load operation state. The lower pressure limit adjustment module 203 is used to continuously monitor the actual working pressure requirements of key hydraulic actuators that are sensitive to pressure in pulse oil supply and pressure inertia maintenance modes, and adjust the pressure fluctuation range of the main pipeline according to the actual working pressure requirements. The pulse oil supply module 204 is used to drive the variable pump to operate at high efficiency when the main pipeline pressure drops to the lower limit of the fluctuation range, so that the main pipeline pressure rises to the upper limit of the pressure fluctuation range, and stops the oil supply of the variable pump or puts it into a zero displacement standby state. The high-priority response module 205 is used to continuously monitor the action commands of the high-priority hydraulic actuator in pulse oil supply and pressure inertia maintenance mode. When a high-priority action command is detected, the pulse oil supply and pressure inertia maintenance mode is immediately interrupted, and the variable pump is driven to operate at maximum displacement.

[0076] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A hydraulic control method for a hydraulic power station, characterized in that, The method includes the following steps: Based on the production task instruction flow, determine whether the hydraulic power station is in a long-term low-load operation state; If the hydraulic power unit is in a long-term low-load operation state, switch the operating mode of the hydraulic power unit to pulse oil supply and pressure inertia maintenance mode. In the pulse oil supply and pressure inertia maintenance mode, the actual working pressure requirements of the pressure-sensitive key hydraulic actuators are continuously monitored, and the pressure fluctuation range of the main pipeline is adjusted according to the actual working pressure requirements. When the pressure in the main pipeline drops to the lower limit of the fluctuation range, the variable pump is driven to operate at high efficiency to raise the pressure in the main pipeline to the upper limit of the pressure fluctuation range, and the oil supply of the variable pump is stopped or it is put into a zero-displacement standby state. In pulse oil supply and pressure inertia maintenance mode, the action commands of high-priority hydraulic actuators are continuously monitored. When a high-priority action command is detected, the pulse oil supply and pressure inertia maintenance mode is immediately interrupted, and the variable pump is driven to operate at maximum displacement. The step of continuously monitoring the actual working pressure demand of the pressure-sensitive key hydraulic actuators in the pulse oil supply and pressure inertia maintenance mode, and adjusting the pressure fluctuation range of the main pipeline according to the actual working pressure demand, includes: In the pulse oil supply and pressure inertia maintenance mode, the actual working pressure requirements of the pressure-sensitive key hydraulic actuators are continuously monitored. After the variable pump stops supplying oil, monitor the time required for the main pipeline pressure to drop from the initial pressure to the termination pressure. By comparing the required time with a preset reference time, the change in the main pipeline pressure decay rate is determined; Assess the internal leakage trend of the critical hydraulic actuator based on the change in the pressure decay rate; Based on the actual working pressure requirements and the internal leakage trend, adjust the lower limit of the main pipeline pressure fluctuation range to compensate for the loss of effective output force of the key hydraulic actuator. Prior to the step of monitoring the time required for the main pipeline pressure to drop from the initial pressure to the final pressure, the following steps are included: Identify currently active critical hydraulic actuators and isolate the hydraulic circuits of non-critical hydraulic actuators during time monitoring; The steps for assessing the internal leakage trend of the critical hydraulic actuator based on the change in the pressure decay rate include: Based on the comparison between the monitored time and the preset baseline time, and the change in the pressure decay rate of the currently active critical hydraulic actuators in the isolated state, the internal leakage trend of the currently active critical hydraulic actuators is assessed and identified. The step of isolating the hydraulic circuits of other non-critical hydraulic actuators during time monitoring includes: During the time monitoring period, non-critical hydraulic actuators that share a supply or return path with currently active critical hydraulic actuators are identified; The supply branch valves and / or isolation valves on the common return path of the non-critical hydraulic actuator are controlled in a coordinated manner to block the connection between the non-critical hydraulic actuator and the main pipeline, thereby isolating the hydraulic circuit of the non-critical hydraulic actuator. After the blocking operation is completed, monitor the residual pressure or flow rate of the non-critical hydraulic actuator circuit; When the residual pressure or flow exceeds a preset threshold, auxiliary pressure relief or secondary isolation operations are performed to eliminate the interference of the residual pressure or flow on the pressure decay rate of the main pipeline. The steps for identifying currently active key hydraulic actuators include: Acquire production task instructions and status feedback information from key hydraulic actuators; Based on the production task instruction information and the status feedback information of each key hydraulic actuator, identify the hydraulic actuator currently in operation as the active hydraulic actuator; The steps for performing auxiliary depressurization or secondary isolation operations include: Continuously monitor the residual pressure or flow rate of the non-critical hydraulic actuator circuit; Adjust the intensity or duration of the auxiliary pressure relief or secondary isolation operation based on the monitored residual pressure or flow rate; Continue to perform the adjusted auxiliary pressure relief or secondary isolation operation until the residual pressure or flow rate of the non-critical hydraulic actuator circuit drops below the preset threshold.

2. The hydraulic control method for a hydraulic power station according to claim 1, characterized in that, The process of setting the preset threshold includes: Obtain the current operating parameters of the hydraulic power unit; Based on the current operating parameters, the preset threshold is initially determined; Under preset calibration conditions, monitor the residual pressure or flow decay process of the non-critical hydraulic actuator circuit; Based on the monitoring results of the residual pressure or flow decay process, update the baseline decay characteristics of the non-critical hydraulic actuator circuit; Based on the aforementioned baseline attenuation characteristics, the initially determined preset threshold is adjusted for compensation.

3. The hydraulic control method for a hydraulic power station according to claim 2, characterized in that, The step of updating the reference attenuation characteristics of the non-critical hydraulic actuator circuit includes: Obtain the monitoring results of the residual pressure or flow rate decay process; The monitoring results are processed based on a preset attenuation model. Based on the data processing results, the parameters of the attenuation model are determined; The determined model parameters are used as the reference attenuation characteristics of the non-critical hydraulic actuator circuit.

4. The hydraulic control method for a hydraulic power station according to claim 3, characterized in that, The process of constructing the preset attenuation model includes: The attenuation model is determined based on the compressibility characteristics of hydraulic oil; The attenuation model is determined based on the damping characteristics of the hydraulic circuit; The attenuation model is determined to be in the form of exponential attenuation, and the attenuation model is constructed by combining compression characteristics and damping characteristics.

Images