Method and system for monitoring internal leakage of mechanical hydraulic system of water turbine governor

Abstract

The invention relates to the technical field of hydraulic turbine speed regulators, and discloses a hydraulic turbine speed regulator mechanical hydraulic system inner leakage monitoring method and system, and the method comprises the steps: building a hydraulic system model, collecting hydraulic system data, and carrying out the preprocessing. Monitoring the running state of the unit, and determining an inner leakage calculation starting condition; and monitoring the internal leakage of the hydraulic system, and correcting the internal leakage to obtain the accurate internal leakage. An inner leakage threshold value is set according to the accurate leakage, and when the inner leakage exceeds the threshold value, the system automatically gives an alarm. The monitoring precision of the operation state of the hydraulic system is improved. And the monitoring sensitivity and accuracy of the hydraulic system are improved. And monitoring errors caused by environment change and system fluctuation are reduced. A dynamic threshold setting and real-time alarm mechanism ensures safe and stable operation of the system. And the reliability and the practicability of the hydraulic system are improved. And the effect of effectively preventing and treating potential problems of the hydraulic system in advance is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of turbine speed governors, and in particular to a method and a system for monitoring the internal leakage of a mechanical hydraulic system of a turbine speed governor. Background Art

[0002] The application of hydraulic systems in turbine speed governors has a long history. With the improvement of industrial automation, hydraulic systems are widely used in various mechanical systems due to their advantages such as high efficiency, precise control and fast response. However, hydraulic systems often face internal leakage problems in actual operation, which not only affects the working efficiency of the system, but also may cause equipment damage and safety hazards. In order to ensure the safety and reliability of hydraulic systems, it is particularly important to effectively monitor and detect hydraulic systems. Traditional monitoring methods are usually based on a single parameter, such as pressure or flow, and the system status is judged by monitoring the changes in these parameters. These methods are feasible in theory, but in actual applications, due to interference from factors such as ambient temperature, system load fluctuations and sensor errors, the monitoring results are often error-prone and cannot accurately reflect the true status of the system. In addition, the existing technology generally uses fixed thresholds for monitoring and alarming, lacks an adaptive adjustment mechanism, and leads to frequent false alarms and missed alarms under complex working conditions.

[0003] The deficiencies of the existing technology in hydraulic system monitoring are mainly reflected in the following aspects: First, the single parameter monitoring method fails to fully reflect the operating status of the hydraulic system and ignores the impact of temperature changes and system load fluctuations, resulting in large deviations in the monitoring results. Secondly, the traditional method fails to effectively correct the sensor error and directly uses the original data for status monitoring, which is not accurate. Thirdly, the fixed threshold alarm mechanism lacks flexibility and cannot adapt to real-time changes under complex working conditions, resulting in reduced system reliability. In summary, the existing technology has obvious limitations in hydraulic system monitoring, and there is an urgent need for a hydraulic system monitoring method that can comprehensively consider multiple influencing factors and improve monitoring accuracy and reliability. Especially in the field of industrial automation and control, accurate system monitoring is particularly important to ensure the safety and efficiency of the system. Summary of the invention

[0004] In view of the above-mentioned problems, the present invention is proposed.

[0005] Therefore, the technical problem solved by the present invention is that the accuracy and reliability of the existing hydraulic system internal leakage detection method are insufficient. The traditional method mainly relies on the change of a single parameter to estimate the internal leakage, resulting in a large error in the calculation result of the internal leakage. In addition, the existing technology usually uses a fixed threshold for internal leakage monitoring and alarm, lacks an adaptive adjustment mechanism, cannot adapt to real-time changes under complex working conditions, and is prone to false alarms and missed alarms.

[0006] To solve the above technical problems, the present invention provides the following technical solutions: A method for monitoring the internal leakage of a hydraulic system of a turbine governor, comprising: establishing a hydraulic system model, collecting hydraulic system data, and performing preprocessing.

[0007] Monitor the operating status of the unit and determine the conditions for starting to calculate the internal leakage.

[0008] Monitor the internal leakage of the hydraulic system, correct the internal leakage and obtain the accurate internal leakage.

[0009] The internal leakage threshold is set according to the precise leakage amount. When the internal leakage exceeds the threshold, the system will automatically alarm.

[0010] As a preferred solution of the method for monitoring internal leakage of a hydraulic system of a turbine governor described in the present invention, the establishment of a hydraulic system model includes determining components of the hydraulic system, including a hydraulic pump, a hydraulic cylinder, a pressure tank, a main pressure regulating valve, a relay, pipelines and connectors, a control valve and an oil storage tank.

[0011] Create a physical model of the hydraulic system, define the parameters of each component, and define the input and output of the hydraulic system.

[0012] As a preferred solution of the method for monitoring internal leakage of a hydraulic system of a turbine governor described in the present invention, the collection of hydraulic system data and preprocessing includes installing sensors to collect pressure, flow, temperature, hydraulic cylinder position, pressure tank oil level and relay stroke change data.

[0013] The preprocessing is data cleaning, removing outliers and noise data, and filling missing values ​​using the averaging method.

[0014] As a preferred scheme of the method for monitoring internal leakage of the mechanical hydraulic system of a turbine governor described in the present invention, the monitoring unit operating status and determining the conditions for starting to calculate the internal leakage include monitoring pressure, flow fluctuations, temperature, and position changes, and calculating thresholds.

[0015] The pressure mutation threshold is expressed as: , in, represents the pressure variation function over time, represents the mean value of the pressure change, represents the standard deviation of pressure variation, Indicates time.

[0016] The traffic fluctuation threshold is expressed as: , in, represents the flow value at the i-th time point, represents the mean value of flow rate change, It represents the standard deviation of flow rate variation, and n is the total number of monitored flow rate data points.

[0017] The temperature anomaly threshold is expressed as: , in, represents the temperature value at the i-th time point, represents the mean value of temperature change, represents the standard deviation of temperature variation, and n represents the total number of monitored temperature data points.

[0018] The position change threshold is expressed as: , in, represents the position value at the i-th time point, represents the mean of the position change, represents the standard deviation of the position change, and n represents the total number of monitoring position data points.

[0019] When any of the following conditions is met, the internal leakage calculation begins: , , , , in, Indicates pressure changes, Indicates flow rate changes. Indicates temperature change, Indicates position change, represents the pressure at time t, represents the flow rate at time t, represents the temperature at time t, represents the position at time t.

[0020] As a preferred solution of the method for monitoring the internal leakage of the hydraulic system of the turbine governor of the present invention, wherein: the monitoring of the internal leakage of the hydraulic system includes monitoring the change of the oil volume in the pressure tank, which is expressed as: , in, Indicates t 1 Check the oil level in the pressure tank at all times. Indicates the oil level of the pressure tank at time t, Indicates the cross-sectional area of ​​the pressure tank.

[0021] Monitor the servomotor oil consumption, expressed as: , in, Indicates t i The relay stroke sensor value at that moment, Indicates t 1 to s The absolute cumulative value of the relay stroke change at the moment, Represents the cross-sectional area of ​​the relay.

[0022] Monitor the main pressure regulating valve i Time to t i+1 Oil consumption at any time, set t i The value of the main pressure regulating valve stroke sensor at the moment When the main pressure regulating valve t i Time to t i+1 The amount of oil used at any given moment is expressed as: , when When the main pressure regulating valve t i Time to t i+1 The amount of oil used at any given moment is expressed as: , Monitor the oil consumption of the main pressure regulating valve, expressed as: , The internal leakage of the hydraulic system is expressed as: , in, Indicates the cross-sectional area of ​​the main pressure distribution valve closed chamber control cylinder. Indicates the cross-sectional area of ​​the main pressure distribution valve opening control cylinder. Indicates the oil pump loading interval duration.

[0023] As a preferred solution of the method for monitoring internal leakage of a turbine governor mechanical hydraulic system according to the present invention, the correction of the internal leakage to obtain accurate internal leakage includes correcting the internal leakage by taking into account two factors: system load fluctuation and sensor error.

[0024] System load fluctuations cause changes in the pressure and flow of the hydraulic system. The fluctuations are random. The variance of the load fluctuations is used to describe the severity of the load fluctuations. The load fluctuation correction term is expressed as: , in, represents the function of load changing with time, Indicates the mean value of the load and is used to centralize load fluctuation data.

[0025] Sensor error directly affects the accuracy of the measured data. The error presents nonlinear characteristics. The error value is smoothed by logarithmic transformation of the error, and the error influence is accumulated by integration. The sensor error correction term is expressed as: , in, Represents the sensor error as a function of time.

[0026] The final internal leakage correction is: , in, Indicates the load fluctuation correction factor, Indicates the sensor error correction factor.

[0027] As a preferred solution of the method for monitoring internal leakage of a mechanical hydraulic system of a turbine governor according to the present invention, the internal leakage threshold is set according to the precise leakage, and the system automatically alarms when the internal leakage exceeds the threshold, including setting three internal leakage thresholds, including a warning threshold, a risk threshold and a fault threshold.

[0028] When the internal leakage exceeds the warning threshold, the system sends a message to the operator: The system detects that the internal leakage exceeds the warning threshold. Please check the system operation status. It is recommended to check the components of the hydraulic system to ensure that there is no obvious leakage. There is no need to shut down immediately, but the system needs to be checked as soon as possible.

[0029] When the internal leakage exceeds the risk threshold, the system sends a message to the operator: The system detects that the internal leakage exceeds the risk threshold and there is a risk of leakage in the system. Please check the components of the hydraulic system immediately, determine the source of the leakage and repair it. Decide whether to shut down the machine based on the actual situation to avoid further damage.

[0030] When the internal leakage exceeds the fault threshold, the system sends a message to the operator: the system detects that the internal leakage exceeds the fault threshold and the system has a serious leak. Please stop the machine immediately to check the hydraulic system and repair all leaking parts to prevent system damage or safety accidents.

[0031] A system for calculating the internal leakage of a mechanical hydraulic system of a turbine speed governor, characterized in that it comprises: The data acquisition module establishes the hydraulic system model, collects the hydraulic system data, and performs preprocessing.

[0032] Confirm the start calculation module, monitor the unit operation status, and determine the conditions for starting calculation of internal leakage.

[0033] The calculation module monitors the internal leakage of the hydraulic system, corrects the internal leakage and obtains the accurate internal leakage.

[0034] The early warning module sets the internal leakage threshold according to the precise leakage amount. When the internal leakage exceeds the threshold, the system automatically alarms.

[0035] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0036] A computer-readable storage medium stores a computer program, which implements the steps of the method described above when executed by a processor.

[0037] Beneficial effects of the invention: Our invention improves the accuracy of monitoring the operating status of the hydraulic system. It improves the sensitivity and accuracy of monitoring the hydraulic system. It reduces monitoring errors caused by environmental changes and system fluctuations. Dynamic threshold setting and real-time alarm mechanism ensure the safe and stable operation of the system. It improves the reliability and practicality of the hydraulic system. It achieves the effect of effectively preventing and pre-processing potential problems of the hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them: Figure 1 The first embodiment of the present invention provides a method and system for monitoring the internal leakage of a hydraulic system of a turbine governor. DETAILED DESCRIPTION

[0039] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0040] Example 1, reference Figure 1 , as one embodiment of the present invention, provides a method for monitoring the internal leakage of a hydraulic system of a turbine governor, comprising: S1: Establish a hydraulic system model, collect hydraulic system data, and perform preprocessing.

[0041] Building a hydraulic system model includes determining the components of the hydraulic system, including hydraulic pumps, hydraulic cylinders, pressure tanks, main pressure regulating valves, servomotors, pipes and connectors, control valves, and oil storage tanks.

[0042] Use MATLAB to create a physical model of the hydraulic system, define the parameters of each component, and define the input and output of the hydraulic system.

[0043] It should be noted that the hydraulic system input includes system pressure, flow, control signal, etc. The output includes the hydraulic cylinder position.

[0044] Install sensors to collect data on pressure, flow, temperature, hydraulic cylinder position, pressure tank oil level and servomotor stroke change.

[0045] The preprocessing is data cleaning, removing outliers and noise data, and filling missing values ​​using the averaging method.

[0046] S2: Monitor the operating status of the unit and determine the conditions for starting to calculate the internal leakage.

[0047] Monitor pressure, flow fluctuations, temperature, and position changes, and calculate thresholds.

[0048] The pressure mutation threshold is expressed as: , in, represents the pressure variation function over time, represents the mean value of the pressure change, represents the standard deviation of pressure variation, Indicates time.

[0049] It should be noted that the pressure mutation threshold formula can capture any rapid pressure changes in the system, reflecting potential abnormalities or failures in the system. Through the integration method, the formula takes into account the cumulative effect of pressure changes over time, making the results more stable and reliable. The mean and standard deviation are introduced to dynamically adjust the threshold to adapt to different system operating conditions. This not only improves the sensitivity to abnormal conditions, but also avoids misjudgments caused by short-term fluctuations.

[0050] The traffic fluctuation threshold is expressed as: , in, represents the flow value at the i-th time point, represents the mean value of flow rate change, It represents the standard deviation of flow rate variation, and n is the total number of monitored flow rate data points.

[0051] It should be noted that the flow fluctuation threshold formula uses the flow changes of all collection points, accumulates and sums them, and combines them with logarithmic function processing to reflect the overall trend and fluctuation of flow changes in the system. By considering the mean and standard deviation, normal fluctuations and abnormal fluctuations can be effectively distinguished. This method is sensitive to large flow changes and can resist small noise interference.

[0052] The temperature anomaly threshold is expressed as: , in, represents the temperature value at the i-th time point, represents the mean value of temperature change, represents the standard deviation of temperature variation, and n represents the total number of monitored temperature data points.

[0053] It should be noted that the temperature anomaly threshold formula amplifies the impact of temperature changes in the form of a sum of squares, and is particularly sensitive to large temperature fluctuations. The design of the denominator allows the formula to normalize the mean and standard deviation, ensuring the adaptability of the threshold.

[0054] The position change threshold is expressed as: , in, represents the position value at the i-th time point, represents the mean of the position change, represents the standard deviation of the position change, and n represents the total number of monitoring position data points.

[0055] It should be noted that the position change threshold formula uses exponential normalization to make the response to position changes smoother and more adaptable. Taking the mean and standard deviation into account, small random changes can be effectively filtered out and focus on significant displacement changes.

[0056] When any of the following conditions is met, the internal leakage calculation begins: , , , , in, Indicates pressure changes, Indicates flow rate changes. Indicates temperature change, Indicates position change, represents the pressure at time t, represents the flow rate at time t, represents the temperature at time t, represents the position at time t.

[0057] It should be noted that in a hydraulic system, any abnormal change in any parameter may indicate the occurrence of internal leakage or other faults. By monitoring multiple parameters and starting the internal leakage calculation when one of the parameters exceeds the threshold, the sensitivity and timeliness of the system can be improved.

[0058] S3: Monitor the internal leakage of the hydraulic system, correct the internal leakage, and obtain the accurate internal leakage.

[0059] Monitor the oil volume change in the pressure tank, expressed as: , in, Indicates t 1 Check the oil level in the pressure tank at all times. Indicates the oil level of the pressure tank at time t, Indicates the cross-sectional area of ​​the pressure tank.

[0060] Monitor the servomotor oil consumption, expressed as: , in, Indicates t i The relay stroke sensor value at that moment, Indicates t 1 to s The absolute cumulative value of the relay stroke change at the moment, Represents the cross-sectional area of ​​the relay.

[0061] Monitor the main pressure regulating valve i Time to t i+1 Oil consumption at any time, set t i The value of the main pressure regulating valve stroke sensor at the moment When the main pressure regulating valve t i Time to t i+1 The amount of oil used at any given moment is expressed as: , when When the main pressure regulating valve t i Time to t i+1 The amount of oil used at any given moment is expressed as: , Monitor the oil consumption of the main pressure regulating valve, expressed as: , The internal leakage of the hydraulic system is expressed as: , in, Indicates the cross-sectional area of ​​the main pressure distribution valve closed chamber control cylinder. Indicates the cross-sectional area of ​​the main pressure distribution valve opening control cylinder. Indicates the oil pump loading interval duration.

[0062] Taking into account the system load fluctuation and sensor error, the internal leakage is corrected.

[0063] System load fluctuations cause changes in the pressure and flow of the hydraulic system. The fluctuations are random. The variance of the load fluctuations is used to describe the severity of the load fluctuations. The load fluctuation correction term is expressed as: , in, represents the function of load changing with time, Indicates the mean value of the load and is used to centralize load fluctuation data.

[0064] Sensor error directly affects the accuracy of the measured data. The error presents nonlinear characteristics. The error value is smoothed by logarithmic transformation of the error, and the error influence is accumulated by integration. The sensor error correction term is expressed as: , in, Represents the sensor error as a function of time.

[0065] The final internal leakage correction is: , in, Indicates the load fluctuation correction factor, Indicates the sensor error correction factor.

[0066] It should be noted that the specific values ​​of the load fluctuation correction coefficient and the sensor error correction coefficient are obtained through experimental data. The experimental process is as follows: Experimental equipment: hydraulic system test bench, including hydraulic pump, hydraulic cylinder, pressure sensor, flow sensor, temperature sensor, position sensor, etc.

[0067] Experimental conditions: Multiple experiments were conducted under different load and sensor accuracy conditions.

[0068] Experimental steps: Record initial internal leakage and measure system load and sensor error ϵ(t).

[0069] Furthermore, the load variation over time can be obtained through experimental data collection. Usually the load variation of the hydraulic system is random and has a certain regular fluctuation. The load variation over time can be represented by a linear model with random disturbance: , in, Represents the load at time t. represents the reference value of the load. A represents the amplitude of the load fluctuation. ω represents the angular frequency of the load fluctuation. ϕ represents the phase angle. η(t) represents the random disturbance term, which is Gaussian white noise and represents the random fluctuation of the load.

[0070] The change of sensor error over time can be obtained by analyzing the long-term monitoring data of the sensor. Affected by system noise, environmental factors and the accuracy of the sensor itself, the change of sensor error over time is represented by a random walk model: , in, Represents the sensor error at time t. represents the initial error. Indicates the amplitude of error fluctuation. represents independent standard Brownian motion and represents random variation of the error.

[0071] Calculate each correction item and adjust the correction coefficient , By comparing the error between the corrected internal leakage and the actual measured internal leakage, the most appropriate correction coefficient is determined. The experimental results are shown in Table 1.

[0072] Table 1 Correction coefficient value table , When the load fluctuation correction coefficient is 0.6, the error of the internal leakage after correction is the smallest.

[0073] When the sensor error correction coefficient is 0.6, the error of the internal leakage after correction is the smallest.

[0074] S4: Set the internal leakage threshold according to the precise leakage amount. When the internal leakage exceeds the threshold, the system will automatically alarm.

[0075] Set three internal leakage thresholds, including warning threshold, risk threshold and failure threshold.

[0076] It should be noted that in order to set the internal leakage threshold, it is necessary to analyze the historical experimental data and conclude that when the internal leakage exceeds a certain threshold, the system may be at risk. The following is the designed experimental process and analysis results.

[0077] Experimental equipment: hydraulic system test bench, including hydraulic pump, hydraulic cylinder, pressure sensor, flow sensor, temperature sensor, position sensor, etc.

[0078] Experimental conditions: Conduct multiple sets of experiments under different operating conditions and record the internal leakage and system status.

[0079] Experimental steps: Initialize the hydraulic system and ensure that the system is in normal operation. Set different internal leakage amounts (by adjusting system parameters or introducing artificial faults). Record the internal leakage amount and system operation status (including whether there is a fault) of each experimental group.

[0080] Analyze the data, determine the relationship between internal leakage and system failure, and set the internal leakage threshold. The experimental results are shown in Table 2.

[0081] Table 2 Experimental results of internal leakage and system status , According to the experimental data analysis, when the internal leakage exceeds 5.20L, the system begins to show a warning state. When it exceeds 5.50L, the system has a significant leakage risk. When it exceeds 5.80L, the system has a serious fault. Therefore, the internal leakage threshold is set to a warning threshold of 5.20L, a risk threshold of 5.50L, and a fault threshold of 5.80L.

[0082] When the internal leakage exceeds the warning threshold, the system sends a message to the operator: The system detects that the internal leakage exceeds the warning threshold. Please check the system operation status. It is recommended to check the components of the hydraulic system to ensure that there is no obvious leakage. There is no need to shut down immediately, but the system needs to be checked as soon as possible.

[0083] When the internal leakage exceeds the risk threshold, the system sends a message to the operator: The system detects that the internal leakage exceeds the risk threshold and there is a risk of leakage in the system. Please check the components of the hydraulic system immediately, determine the source of the leakage and repair it. Decide whether to shut down the machine based on the actual situation to avoid further damage.

[0084] When the internal leakage exceeds the fault threshold, the system sends a message to the operator: the system detects that the internal leakage exceeds the fault threshold and the system has a serious leak. Please stop the machine immediately to check the hydraulic system and repair all leaking parts to prevent system damage or safety accidents.

[0085] This embodiment also provides a system for calculating the internal leakage of a hydraulic system of a turbine governor, specifically: The data acquisition module establishes the hydraulic system model, collects the hydraulic system data, and performs preprocessing.

[0086] Confirm the start calculation module, monitor the unit operation status, and determine the conditions for starting calculation of internal leakage.

[0087] The calculation module monitors the internal leakage of the hydraulic system, corrects the internal leakage and obtains the accurate internal leakage.

[0088] The early warning module sets the internal leakage threshold according to the precise leakage amount. When the internal leakage exceeds the threshold, the system automatically alarms.

[0089] The computer device may be a server. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected via a system bus, and the communication interface is connected to the system bus via the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data cluster data of the power monitoring system. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection.

[0090] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0091] Embodiment 2, an embodiment of the present invention, provides a method and system for monitoring the internal leakage of a mechanical hydraulic system of a turbine governor. In order to verify the beneficial effects of the present invention, a scientific demonstration is carried out through simulation comparative experiments.

[0092] Our invention and the prior art were tested on the same turbine governor mechanical hydraulic system.

[0093] In the prior art, the calculation of the internal leakage of the hydraulic system is usually based on the monitoring of a single parameter. The existing method includes the following steps: Data collection: Pressure sensor: installed at key locations in the hydraulic system to monitor pressure changes within the system in real time.

[0094] Flow sensor: measures the flow of hydraulic oil and records flow changes.

[0095] Data processing: Perform basic processing on the collected data to remove obvious outliers and noise data.

[0096] Internal leakage monitoring: The internal leakage is calculated based on the pressure and flow rate. The experimental results are shown in Table 3.

[0097] Table 3 Experimental results of prior art , In the experimental data table of the prior art, the internal leakage is calculated by the traditional method without any correction. It can be seen from the table that there is a large deviation between the internal leakage calculation result of the prior art and the actual internal leakage. For example, in experimental group 5, the internal leakage calculated by the prior art is 5.50L, while the actual internal leakage is 5.30L, with an error of 0.20L. This shows that the calculation results of the prior art are not accurate enough when dealing with complex working conditions and system fluctuations.

[0098] Our invention experimental steps: In order to verify the effect of the internal leakage monitoring method of the hydraulic system of the turbine governor invented by us, we compared it with the existing technology and conducted several experiments. The experimental equipment includes hydraulic pump, hydraulic cylinder, pressure tank, main pressure regulating valve, relay, pressure sensor, flow sensor, temperature sensor and position sensor. The data acquisition uses a high-precision data acquisition card, and real-time monitoring and recording are carried out through LabVIEW.

[0099] System initialization: Initialize the hydraulic system, ensure that all equipment is in normal working condition, and check and confirm the calibration accuracy of each sensor.

[0100] Data collection includes pressure data, flow data, temperature data, position data, pressure tank oil level, relay stroke data, main pressure regulating valve stroke data, load data, and sensor error data.

[0101] Data preprocessing: Clean the data to remove outliers and noise.

[0102] Internal leakage calculation: Monitor the internal leakage of the hydraulic system, calculate the load fluctuation correction term, calculate the sensor error correction term, perform internal leakage correction, and obtain the accurate internal leakage. The experimental results are shown in Table 4.

[0103] Table 4 Experimental results of our invention , In Table 4, the internal leakage is the initial calculation result obtained by comprehensively considering multiple parameters. By introducing the load fluctuation correction term and the sensor error correction term, the initial calculation result is corrected to obtain the final internal leakage. The initial internal leakage calculation result of our invention is closer to the actual internal leakage than the prior art. For example, in Experimental Group 5, the initial internal leakage of our invention is 5.55L, while the calculation result of the prior art is 5.50L, with a smaller error.

[0104] The corrected internal leakage is almost completely consistent with the actual internal leakage, indicating that our invention can significantly improve the accuracy of internal leakage calculation by correcting load fluctuations and sensor errors. For example, in experimental group 5, the corrected internal leakage is 5.30L, which is completely consistent with the actual internal leakage.

[0105] In summary, through comparative analysis of experimental data, the internal leakage monitoring method of the hydraulic system of the turbine governor invented by us is obviously innovative and advantageous, and can more accurately calculate the internal leakage and improve the reliability and safety of the system. Compared with the prior art, our invention is not only more sophisticated in data collection and preliminary calculation, but also significantly improves the accuracy of internal leakage calculation, ensuring the stable operation of the hydraulic system.

[0106] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for monitoring internal leakage of a hydraulic system of a turbine governor, characterized in that: include: Establish hydraulic system model, collect hydraulic system data and perform preprocessing; Monitor the operating status of the unit and determine the conditions for starting calculation of internal leakage; Monitor the internal leakage of the hydraulic system, correct the internal leakage and obtain the accurate internal leakage; The internal leakage threshold is set according to the precise leakage amount. When the internal leakage exceeds the threshold, the system will automatically alarm.

2. The method for monitoring internal leakage of a hydraulic system of a turbine governor according to claim 1, characterized in that: The establishment of the hydraulic system model includes determining the components of the hydraulic system, including a hydraulic pump, a hydraulic cylinder, a pressure tank, a main pressure regulating valve, a servomotor, pipelines and connectors, a control valve and an oil storage tank; Create a physical model of the hydraulic system, define the parameters of each component, and define the input and output of the hydraulic system.

3. The method for monitoring internal leakage of a hydraulic system of a turbine governor as claimed in claim 2, characterized in that: The collecting of hydraulic system data and preprocessing includes installing sensors to collect pressure, flow, temperature, hydraulic cylinder position, pressure tank oil level and servomotor stroke change data; The preprocessing is data cleaning, removing outliers and noise data, and filling missing values ​​using the averaging method.

4. The method for monitoring internal leakage of a hydraulic system of a turbine governor as claimed in claim 3, characterized in that: The monitoring of the unit operation status and determining the conditions for starting to calculate the internal leakage include monitoring pressure, flow fluctuation, temperature, and position changes and calculating thresholds; The pressure mutation threshold is expressed as: ， in, represents the pressure variation function over time, represents the mean value of the pressure change, represents the standard deviation of pressure variation, Indicates time; The traffic fluctuation threshold is expressed as: ， in, represents the flow value at the i-th time point, represents the mean value of flow rate change, It represents the standard deviation of flow rate change, and n is the total number of monitored flow rate data points; The temperature anomaly threshold is expressed as: ， in, represents the temperature value at the i-th time point, represents the mean value of temperature change, represents the standard deviation of temperature variation, and n represents the total number of monitored temperature data points; The position change threshold is expressed as: ， in, represents the position value at the i-th time point, represents the mean of the position change, represents the standard deviation of the position change, and n represents the total number of monitoring position data points; When any of the following conditions is met, the internal leakage calculation begins: ， ， ， ， in, Indicates pressure changes, Indicates flow rate changes. Indicates temperature change, Indicates position change, represents the pressure at time t, represents the flow rate at time t, represents the temperature at time t, represents the position at time t.

5. The method for monitoring internal leakage of a hydraulic system of a turbine governor as claimed in claim 4, characterized in that: The monitoring of the internal leakage of the hydraulic system includes monitoring the change of the oil volume in the pressure tank, which is expressed as: ， in, Indicates the oil level of the pressure tank at time t1, Indicates the oil level of the pressure tank at time t, Indicates the cross-sectional area of ​​the pressure tank; Monitor the servomotor oil consumption, expressed as: ， in, Indicates t i The relay stroke sensor value at that moment, Indicates t1 to t s The absolute cumulative value of the relay stroke change at the moment, represents the cross-sectional area of ​​the servomotor; Monitor the main pressure regulating valve i Time to t i+1 Oil consumption at any time, set t i The value of the main pressure regulating valve stroke sensor at the moment When the main pressure regulating valve t i Time to t i+1 The amount of oil used at any given moment is expressed as: ， when When the main pressure regulating valve t i Time to t i+1 The amount of oil used at any given moment is expressed as: ， Monitor the oil consumption of the main pressure regulating valve, expressed as: ， The internal leakage of the hydraulic system is expressed as: ， in, Indicates the cross-sectional area of ​​the main pressure distribution valve closed chamber control cylinder. Indicates the cross-sectional area of ​​the main pressure distribution valve opening control cylinder. Indicates the oil pump loading interval duration.

6. The method for monitoring internal leakage of a hydraulic system of a turbine governor as claimed in claim 5, characterized in that: The correcting of the internal leakage to obtain the accurate internal leakage includes correcting the internal leakage by taking into account two factors: system load fluctuation and sensor error; System load fluctuations cause changes in the pressure and flow of the hydraulic system. The fluctuations are random. The variance of the load fluctuations is used to describe the severity of the load fluctuations. The load fluctuation correction term is expressed as: ， in, represents the function of load changing with time, Indicates the mean value of the load, used to centralize load fluctuation data; Sensor error directly affects the accuracy of the measured data. The error presents nonlinear characteristics. The error value is smoothed by logarithmic transformation of the error, and the error influence is accumulated by integration. The sensor error correction term is expressed as: ， in, represents the function of sensor error changing with time; The final internal leakage correction is: ， in, Indicates the load fluctuation correction factor, Indicates the sensor error correction factor.

7. The method for monitoring internal leakage of a hydraulic system of a turbine governor as claimed in claim 6, characterized in that: The internal leakage threshold is set according to the precise leakage amount, and the system automatically alarms when the internal leakage amount exceeds the threshold, including setting three internal leakage thresholds, including a warning threshold, a risk threshold and a fault threshold; When the internal leakage exceeds the warning threshold, the system sends a message to the operator: the system detects that the internal leakage exceeds the warning threshold, please check the system operation status; it is recommended to check the components of the hydraulic system to ensure that there is no obvious leakage; No immediate shutdown is required, but the system needs to be checked as soon as possible; When the internal leakage exceeds the risk threshold, the system sends a message to the operator: the system detects that the internal leakage exceeds the risk threshold and there is a risk of leakage in the system; please check the components of the hydraulic system immediately, determine the source of the leakage and repair it; decide whether to shut down the machine based on the actual situation to avoid further damage; When the internal leakage exceeds the fault threshold, the system sends a message to the operator: the system detects that the internal leakage exceeds the fault threshold and the system has a serious leak. Please stop the machine immediately to check the hydraulic system and repair all leaking parts to prevent system damage or safety accidents.

8. A system for calculating the internal leakage of a hydraulic system of a turbine governor using the method according to any one of claims 1 to 7, characterized in that: Data acquisition module, building hydraulic system model, collecting hydraulic system data and preprocessing; Confirm the calculation module to start, monitor the unit operation status, and determine the conditions for starting the internal leakage calculation; The calculation module monitors the internal leakage of the hydraulic system, corrects the internal leakage, and obtains the accurate internal leakage; The early warning module sets the internal leakage threshold according to the precise leakage amount. When the internal leakage exceeds the threshold, the system automatically alarms.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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