Method for detecting pressure pulsation peak-to-peak value of hydropower station unit under transient condition and related equipment

Abstract

The invention provides a method for detecting a pressure pulsation peak-to-peak value of a hydropower station unit under a transient condition and related equipment. The method comprises the following steps: acquiring a pressure pulsation signal of a preset position in the hydropower station unit; decomposing the pressure pulsation signal to obtain a corresponding trend item signal and a pulsation item signal; performing signal mapping processing on the trend item signal and the pulsation item signal to obtain peak-to-peak values of the pulsation item under different period lengths; and calculating the average value of the peak-to-peak values of the pulsation item under different period lengths to obtain the pressure pulsation peak-to-peak value of the preset position.

Description

Technical Field

[0001] The present disclosure relates to the field of pressure analysis, and in particular to a method for detecting a peak-to-peak value of pressure pulsation of a hydropower station unit under transient conditions and related equipment. Background Art

[0002] Under transient conditions of hydropower station units, the volute pressure rise and the tailwater pressure drop are unstable, which is prone to safety problems. However, the existing pressure peak detection under transient conditions has low accuracy and long analysis time, which cannot meet actual needs. Summary of the invention

[0003] The present invention discloses a method and related equipment for detecting the peak-to-peak value of pressure pulsation of a hydropower station unit under transient conditions, so as to solve the technical problems of low pressure peak detection accuracy and long analysis time under transient conditions of the hydropower station unit to a certain extent.

[0004] In a first aspect, the present disclosure provides a method for detecting a peak-to-peak value of pressure pulsation of a hydropower station unit under transient conditions, comprising:

[0005] Acquiring a pressure pulsation signal at a preset position in the hydropower station unit;

[0006] Decomposing the pressure pulsation signal to obtain corresponding trend item signal and pulsation item signal;

[0007] Performing signal mapping processing on the trend item signal and the pulsation item signal to obtain the peak-to-peak value of the pulsation item under different cycle lengths;

[0008] The average value of the peak-to-peak value of the pulsation item at different cycle lengths is calculated to obtain the peak-to-peak value of the pressure pulsation at the preset position.

[0009] In some embodiments, the pressure pulsation signal is decomposed to obtain corresponding trend item signals and pulsation item signals, including:

[0010] Decomposing the pressure pulsation signal into a plurality of intrinsic mode function components;

[0011] Convolution and local feature extraction are performed on each of the intrinsic mode function components to obtain the trend term signal and the pulsation term signal.

[0012] In some embodiments, performing convolution and local feature extraction on each of the intrinsic mode function components to obtain the trend term signal and the pulsation term signal includes:

[0013] Extracting the low-frequency part of the intrinsic mode function component to obtain the trend term signal;

[0014] The high frequency part of the intrinsic mode function component is extracted to obtain the pulsation term signal.

[0015] In some embodiments, performing signal mapping processing on the trend item signal and the pulsation item signal to obtain the peak-to-peak value of the pulsation item at different cycle lengths includes:

[0016] Determine a first time node corresponding to a maximum eigenvalue and a second time node corresponding to a minimum eigenvalue in the trend item;

[0017] Determine at least one cycle length based on the first time node and / or the second time node;

[0018] For each cycle length, the peak-to-peak value of the pulsation term is obtained based on the difference between the maximum value and the minimum value time of the pulsation term within the cycle length.

[0019] In some embodiments, determining a first time node corresponding to a maximum eigenvalue and a second time node corresponding to a minimum eigenvalue in the trend item includes:

[0020] Based on the time node in the trend item time chain table pointed to by the first pointer of the maximum eigenvalue, obtaining the first time node;

[0021] Based on the time node in the trend item time linked list pointed to by the second pointer of the minimum eigenvalue, the second time node is obtained.

[0022] In some embodiments, calculating the average of the peak-to-peak values ​​of the pulsation terms at different cycle lengths comprises:

[0023] Wherein, A is the average value, n is the number of different cycle lengths, and k is the sequence number of the cycle length.

[0024] In some embodiments, calculating the average value of the peak-to-peak value of the pulsation term at different cycle lengths further includes:

[0025] Calculating the confidence level of the peak-to-peak value of the pulsation item corresponding to each cycle length;

[0026] The average value is calculated based on the peak-to-peak value of the pulsation item corresponding to the confidence level being greater than or equal to the confidence level threshold.

[0027] In a second aspect of the present disclosure, a device for detecting the peak-to-peak value of pressure pulsation of a hydropower station unit under transient conditions is provided, comprising:

[0028] An acquisition module, used for acquiring a pressure pulsation signal at a preset position in a unit of the hydropower station;

[0029] A decomposition module, used for decomposing the pressure pulsation signal to obtain corresponding trend item signals and pulsation item signals;

[0030] A mapping module, used for performing signal mapping processing on the trend item signal and the pulsation item signal to obtain the peak-to-peak value of the pulsation item under different cycle lengths;

[0031] The mean value module is used to calculate the average value of the peak-to-peak value of the pulsation item under different cycle lengths to obtain the peak-to-peak value of the pressure pulsation at the preset position.

[0032] In some embodiments, the pressure pulsation signal is decomposed to obtain corresponding trend item signals and pulsation item signals, including:

[0033] Decomposing the pressure pulsation signal into a plurality of intrinsic mode function components;

[0034] Convolution and local feature extraction are performed on each of the intrinsic mode function components to obtain the trend term signal and the pulsation term signal.

[0035] In some embodiments, performing convolution and local feature extraction on each of the intrinsic mode function components to obtain the trend term signal and the pulsation term signal includes:

[0036] Extracting the low-frequency part of the intrinsic mode function component to obtain the trend term signal;

[0037] The high frequency part of the intrinsic mode function component is extracted to obtain the pulsation term signal.

[0038] In some embodiments, performing signal mapping processing on the trend item signal and the pulsation item signal to obtain the peak-to-peak value of the pulsation item at different cycle lengths includes:

[0039] Determine a first time node corresponding to a maximum eigenvalue and a second time node corresponding to a minimum eigenvalue in the trend item;

[0040] Determine at least one cycle length based on the first time node and / or the second time node;

[0041] For each cycle length, the peak-to-peak value of the pulsation term is obtained based on the difference between the maximum value and the minimum value time of the pulsation term within the cycle length.

[0042] In some embodiments, determining a first time node corresponding to a maximum eigenvalue and a second time node corresponding to a minimum eigenvalue in the trend item includes:

[0043] Based on the time node in the trend item time chain table pointed to by the first pointer of the maximum eigenvalue, obtaining the first time node;

[0044] Based on the time node in the trend item time linked list pointed to by the second pointer of the minimum eigenvalue, the second time node is obtained.

[0045] In some embodiments, calculating the average of the peak-to-peak values ​​of the pulsation terms at different cycle lengths comprises:

[0046] Wherein, A is the average value, n is the number of different cycle lengths, and k is the sequence number of the cycle length.

[0047] In some embodiments, calculating the average value of the peak-to-peak value of the pulsation term at different cycle lengths further includes:

[0048] Calculating the confidence level of the peak-to-peak value of the pulsation item corresponding to each cycle length;

[0049] The average value is calculated based on the peak-to-peak value of the pulsation item corresponding to the confidence level being greater than or equal to the confidence level threshold.

[0050] In a third aspect of the present disclosure, an electronic device is provided, comprising one or more processors, a memory; and one or more programs, wherein the one or more programs are stored in the memory and executed by the one or more processors, and the programs include instructions for executing the method described in the first aspect.

[0051] According to a fourth aspect of the present disclosure, a non-volatile computer-readable storage medium containing a computer program is provided. When the computer program is executed by one or more processors, the processors execute the method described in the first aspect.

[0052] In a fifth aspect of the present disclosure, a computer program product is provided, comprising computer program instructions, which, when executed on a computer, enable the computer to execute the method described in the first aspect.

[0053] From the above, it can be seen that the present disclosure provides a method and related equipment for detecting the peak-to-peak value of pressure pulsation of a hydropower station unit under transient conditions. The pressure signal at the target position of the hydropower station unit is decomposed by using variational mode decomposition technology to obtain trend terms and pulsation terms; and the peak-to-peak value of the pulsation term under different cycle lengths is obtained by signal mapping calculation, thereby obtaining the peak-to-peak value of pressure pulsation. The accuracy of the peak-to-peak value of pressure pulsation under transient conditions is improved, providing reasonable and accurate technical support for the analysis of related pressure data. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions in the present disclosure or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0055] Figure 1 It is a schematic diagram of a detection architecture for the peak-to-peak value of pressure pulsation of a hydropower station unit under transient conditions according to an embodiment of the present disclosure.

[0056] Figure 2 The figure is a schematic diagram of the hardware structure of an exemplary electronic device according to an embodiment of the present disclosure.

[0057] Figure 3 The present invention is a flow chart of a method for detecting the peak-to-peak value of pressure pulsation of a hydropower station unit under transient conditions according to an embodiment of the present disclosure.

[0058] Figure 4 It is a schematic diagram of a method for detecting the peak-to-peak value of pressure pulsation of a hydropower station unit under transient conditions according to an embodiment of the present disclosure.

[0059] Figure 5 It is a schematic diagram of a device for detecting the peak-to-peak value of pressure pulsation of a hydropower station unit under transient conditions according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0060] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0061] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the embodiments of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0062] It is understandable that before using the technical solutions disclosed in the embodiments of the present disclosure, the types, scope of use, usage scenarios, etc. of the personal information involved in the present disclosure should be informed to the user and the user's authorization should be obtained in an appropriate manner in accordance with relevant laws and regulations.

[0063] For example, in response to receiving an active request from a user, a prompt message is sent to the user to clearly prompt the user that the operation requested to be performed will require obtaining and using the user's personal information. Thus, the user can autonomously choose whether to provide personal information to software or hardware such as an electronic device, application, server, or storage medium that performs the operation of the technical solution of the present disclosure according to the prompt message.

[0064] It is understandable that the above notification and the process of obtaining user authorization are merely illustrative and do not constitute a limitation on the implementation of the present disclosure. Other methods that meet the relevant laws and regulations may also be applied to the implementation of the present disclosure.

[0065] Figure 1 A schematic diagram of a detection architecture for the peak-to-peak value of pressure pulsation of a hydropower station unit under transient conditions according to an embodiment of the present disclosure is shown. Figure 1 The detection architecture 100 of the peak-to-peak value of the pressure pulsation of the hydropower station unit under the transient condition may include a server 110, a terminal 120, and a network 130 providing a communication link. The server 110 and the terminal 120 may be connected via a wired or wireless network 130. The server 110 may be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, security services, and CDN.

[0066] The terminal 120 may be implemented in hardware or software. For example, when the terminal 120 is implemented in hardware, it may be various electronic devices having a display screen and supporting page display, including but not limited to smart phones, tablet computers, e-book readers, laptop portable computers, and desktop computers, etc. When the terminal 120 device is implemented in software, it may be installed in the electronic devices listed above; it may be implemented as multiple software or software modules (such as software or software modules used to provide distributed services), or it may be implemented as a single software or software module, which is not specifically limited here.

[0067] It should be noted that the method for detecting the peak-to-peak value of the pressure pulsation of the hydropower station unit under transient conditions provided in the embodiment of the present application can be executed by the terminal 120 or by the server 110. It should be understood that Figure 1The number of terminals, networks and servers in the embodiment is only for illustration and is not intended to limit the number of terminals, networks and servers. Any number of terminals, networks and servers may be provided as required.

[0068] Figure 2 FIG. 2 shows a schematic diagram of the hardware structure of an exemplary electronic device 200 provided in an embodiment of the present disclosure. Figure 2 As shown, the electronic device 200 may include: a processor 202, a memory 204, a network module 206, a peripheral interface 208 and a bus 210. The processor 202, the memory 204, the network module 206 and the peripheral interface 208 are connected to each other in communication within the electronic device 200 through the bus 210.

[0069] Processor 202 may be a central processing unit (CPU), a detector of the peak-to-peak pressure pulsation of a hydropower station unit under transient conditions, a neural network processor (NPU), a microcontroller (MCU), a programmable logic device, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), or one or more integrated circuits. Processor 202 may be used to perform functions related to the technology described in the present disclosure. In some embodiments, processor 202 may also include multiple processors integrated into a single logical component. For example, Figure 2 As shown, processor 202 may include a plurality of processors 202a, 202b, and 202c.

[0070] The memory 204 may be configured to store data (eg, instructions, computer code, etc.). Figure 2 As shown, the data stored in the memory 204 may include program instructions (for example, program instructions for implementing the method for detecting the peak-to-peak value of the pressure pulsation of the hydropower station unit under transient conditions of the embodiment of the present disclosure) and data to be processed (for example, the memory may store configuration files of other modules, etc.). The processor 202 may also access the program instructions and data stored in the memory 204, and execute the program instructions to operate on the data to be processed. The memory 204 may include a volatile storage device or a non-volatile storage device. In some embodiments, the memory 204 may include a random access memory (RAM), a read-only memory (ROM), an optical disk, a magnetic disk, a hard disk, a solid-state drive (SSD), a flash memory, a memory stick, etc.

[0071] The network module 206 can be configured to provide communication with other external devices to the electronic device 200 via a network. The network can be any wired or wireless network capable of transmitting and receiving data. For example, the network can be a wired network, a local wireless network (e.g., Bluetooth, WiFi, near field communication (NFC) etc.), a cellular network, the Internet or a combination thereof. It is understood that the type of network is not limited to the above specific examples. In some embodiments, the network module 306 can include any number of network interface controllers (NICs), radio frequency modules, transceivers, modems, routers, gateways, adapters, cellular network chips, etc., in any combination.

[0072] The peripheral interface 208 can be configured to connect the electronic device 200 to one or more peripheral devices to achieve information input and output. For example, the peripheral devices can include input devices such as a keyboard, a mouse, a touch pad, a touch screen, a microphone, and various sensors, and output devices such as a display, a speaker, a vibrator, and an indicator light.

[0073] The bus 210 can be configured to transmit information between various components of the electronic device 200 (e.g., the processor 202, the memory 204, the network module 206, and the peripheral interface 208), such as an internal bus (e.g., a processor-memory bus), an external bus (USB port, PCI-E bus), etc.

[0074] It should be noted that, although the architecture of the electronic device 200 only shows the processor 202, the memory 204, the network module 206, the peripheral interface 208 and the bus 210, in the specific implementation process, the architecture of the electronic device 200 may also include other components necessary for normal execution. In addition, it can be understood by those skilled in the art that the architecture of the electronic device 200 may also only include the components necessary for implementing the embodiments of the present disclosure, and does not necessarily include all the components shown in the figure.

[0075] Under transient conditions of the unit, the rise in volute pressure and the drop in tailwater pipe pressure are unstable, which poses a safety problem. The peak-to-peak value of pressure pulsation is the most direct reflection of whether the pressure at the measuring point is stable or not. Under steady-state conditions, when the analysis duration meets certain conditions, the peak-to-peak size is approximately independent of the duration; under transient conditions, the analysis duration is long, and the peak-to-peak value cannot accurately reflect the law of pressure change, while the analysis duration is short, and the peak-to-peak value is meaningless or unstable. Therefore, it is necessary to process the peak-to-peak value analysis of pressure pulsation under transient conditions to obtain a more accurate peak-to-peak value of pressure pulsation. Therefore, how to reduce the detection error of the peak-to-peak value of pressure pulsation under transient conditions and improve detection efficiency have become technical problems that need to be solved urgently.

[0076] In view of this, the embodiment of the present disclosure provides a method and related equipment for detecting the peak-to-peak value of pressure pulsation of a hydropower station unit under transient conditions. The pressure signal at the target position of the hydropower station unit is decomposed by using variational mode decomposition technology to obtain trend terms and pulsation terms; and the peak-to-peak value of the pulsation term under different cycle lengths is calculated by signal mapping, thereby obtaining the peak-to-peak value of pressure pulsation. The accuracy of the peak-to-peak value of pressure pulsation under transient conditions is improved, providing reasonable and accurate technical support for the analysis of related pressure data.

[0077] See also Figure 3 , Figure 3 A schematic flow chart of a method for detecting the peak-to-peak value of pressure pulsation of a hydropower station unit under transient conditions according to an embodiment of the present disclosure is shown. The method for detecting the peak-to-peak value of pressure pulsation of a hydropower station unit under transient conditions according to an embodiment of the present disclosure can be deployed on a server or client. Figure 3 In the present invention, the method 300 for detecting the peak-to-peak value of the pressure pulsation of the hydropower station unit under transient conditions may further include the following steps.

[0078] In step S310, a pressure pulsation signal at a preset position in the hydropower station unit is obtained.

[0079] Among them, the preset position may refer to a specific position in the hydropower station unit that is pre-set according to the design and monitoring requirements and is equipped with a sensor. These positions are usually selected in places that can reflect the key information of the unit's operating status, such as the volute inlet, the tailwater pipe outlet, the periphery of the water guide vane, etc., because these areas are easily affected by the hydrodynamic effects. The pressure pulsation signal may refer to the pressure fluctuations generated inside the pipeline or in specific structural parts due to factors such as the non-uniformity of the water flow, eddy currents, cavitation, etc. when the water flows through the volute, water guide mechanism, runner, etc. during the operation of the hydropower station. This pressure fluctuation that changes rapidly over time is called a pressure pulsation signal, which contains rich information about the operating status of the unit. Sensors can be set at preset positions to sense physical quantities (such as pressure) and convert them into electrical signals. For example, piezoresistive and piezoelectric pressure sensors can monitor pressure changes in real time and convert pressure values ​​into electrical signals for analysis.

[0080] In step S320, the pressure pulsation signal is decomposed to obtain corresponding trend item signals and pulsation item signals.

[0081] Among them, VMD technology can be applied to the collected pressure pulsation signals respectively. VMD decomposes the signal into a series of physically meaningful intrinsic mode functions (IMFs) through an iterative optimization process. Each IMF represents a specific frequency component of the signal, including a trend term (low-frequency component) and a pulsation term (high-frequency component). Specifically, the volute inlet pressure pulsation signal and the tailwater inlet pressure pulsation signal under transient conditions can be collected by sensors. The original pressure pulsation signal is decomposed into multiple IMF components using variational mode decomposition technology for the volute inlet pressure pulsation signal and the tailwater inlet pressure pulsation signal under transient conditions, and each IMF component is convolved to extract local features to obtain the trend term signal and the pulsation term signal of the pressure pulsation signal.

[0082] In some embodiments, the pressure pulsation signal is decomposed to obtain corresponding trend item signals and pulsation item signals, including:

[0083] Decomposing the pressure pulsation signal into a plurality of intrinsic mode function components;

[0084] Convolution and local feature extraction are performed on each of the intrinsic mode function components to obtain the trend term signal and the pulsation term signal.

[0085] In some embodiments, performing convolution and local feature extraction on each of the intrinsic mode function components to obtain the trend term signal and the pulsation term signal includes:

[0086] Extracting the low-frequency part of the intrinsic mode function component to obtain the trend term signal;

[0087] The high frequency part of the intrinsic mode function component is extracted to obtain the pulsation term signal.

[0088] Among them, convolution operation is performed on each IMF component to extract the local features of the signal, enhance the ability to identify signal details, and facilitate subsequent feature analysis. Based on the convolution results, the trend item signal and the pulsation item signal are separated. The trend item reflects the long-term change trend of the signal, while the pulsation item reflects the instantaneous fluctuation characteristics of the signal.

[0089] In step S330, signal mapping processing is performed on the trend item signal and the pulsation item signal to obtain the peak-to-peak value of the pulsation item at different cycle lengths.

[0090] Among them, according to the calculation formula of the signal mapping process, the time nodes corresponding to the maximum and minimum eigenvalues ​​in the trend item are found. This helps to understand the overall trend change of the signal. The pulsation item signal is analyzed periodically, the peak-to-peak value (that is, the difference between the maximum and minimum values ​​of the signal) under different periods is calculated, and the weighted average method (0.2k+0.8 in the formula) is used to comprehensively consider the importance of different periods, where k is the period number and n is the total number of periods. This step aims to extract the typical fluctuation amplitude of the pulsation item.

[0091] In some embodiments, performing signal mapping processing on the trend item signal and the pulsation item signal to obtain the peak-to-peak value of the pulsation item at different cycle lengths includes:

[0092] Determine a first time node corresponding to a maximum eigenvalue and a second time node corresponding to a minimum eigenvalue in the trend item;

[0093] For each cycle length, the peak-to-peak value of the pulsation term is obtained based on the difference between the maximum value and the minimum value time of the pulsation term within the cycle length.

[0094] In some embodiments, determining a first time node corresponding to a maximum eigenvalue and a second time node corresponding to a minimum eigenvalue in the trend item includes:

[0095] Based on the time node in the trend item time chain table pointed to by the first pointer of the maximum eigenvalue, obtaining the first time node;

[0096] Determine at least one cycle length based on the first time node and / or the second time node;

[0097] Based on the time node in the trend item time linked list pointed to by the second pointer of the minimum eigenvalue, the second time node is obtained.

[0098] Among them, since it is impossible to obtain the time node of the transient moment of the signal through the pulsation item, the corresponding time node can be determined through the trend item, and then mapped to the pulsation item to determine the peak-to-peak value of the pulsation item at the corresponding time node. For example, if the time node corresponding to the maximum eigenvalue of the trend item is 3s, then 2.8s~3.2s can be taken and mapped to the pulsation item in this time interval, and the pulsation item data is taken to calculate the peak-to-peak value. Specifically, the maximum / minimum trend item eigenvalue corresponding time node extraction formula may include: the maximum trend item eigenvalue corresponding time node = the trend item maximum eigenvalue pointer → the trend item time chain table; the minimum trend item eigenvalue corresponding time node = the trend item minimum eigenvalue pointer → the trend item time chain table.

[0099] In step S340, the average value of the peak-to-peak value of the pulsation item at different cycle lengths is calculated to obtain the peak-to-peak value of the pressure pulsation at the preset position.

[0100] In some embodiments, calculating the average of the peak-to-peak values ​​of the pulsation terms at different cycle lengths comprises:

[0101] Wherein, A is the average value, n is the number of different cycle lengths, and k is the sequence number of the cycle length.

[0102] Specifically, the trend item and the pulsation item of the volute inlet pressure pulsation signal can be calculated by the signal mapping process, and the peak-to-peak value of the pulsation item of the volute inlet pressure pulsation signal under different periods can be obtained, and the confidence level is 97% (the quantiles are 1.5% and 98.5%); the trend item and the pulsation item of the draft tube inlet pressure pulsation signal obtained by the modal variation module can be calculated by the signal mapping process, and the peak-to-peak value of the pulsation item of the draft tube inlet pressure pulsation signal under different periods can be obtained, and the confidence level is 97% (the quantiles are 1.5% and 98.5%). The average values ​​are taken as the peak-to-peak values ​​of the volute inlet pressure pulsation and the draft tube inlet pressure pulsation under this transient condition.

[0103] In some embodiments, calculating the average value of the peak-to-peak value of the pulsation term at different cycle lengths further includes:

[0104] Calculating the confidence level of the peak-to-peak value of the pulsation item corresponding to each cycle length;

[0105] The average value is calculated based on the peak-to-peak value of the pulsation item corresponding to the confidence level being greater than or equal to the confidence level threshold.

[0106] Among them, in order to improve the robustness of the analysis, a 97% confidence level (i.e., excluding the most extreme 1.5% and 98.5% data points) can be used to calculate the confidence interval of the peak-to-peak value of the pulsation item under different cycles, which helps to eliminate outliers and ensure the reliability of the results. The pressure pulsation signals at the volute inlet and the draft tube inlet are respectively determined according to the calculated peak-to-peak average value of the pulsation item (considering the confidence interval) to determine the representative peak-to-peak value under the transient condition. This provides an important quantitative indicator for evaluating the operating status of the system and predicting potential failures.

[0107] See also Figure 4 , Figure 4 A schematic diagram of a method for detecting a peak-to-peak value of pressure pulsation of a hydropower station unit under transient conditions according to an embodiment of the present disclosure is shown. Figure 4In the test, the operating condition can be set as: a single unit operates normally at a load of 306MW, and suddenly removes 100% of the rated load to simulate the system response of emergency shutdown or sudden load change in the transient operating condition test scenario of the hydropower station. Environmental conditions can include: the water level of the upper reservoir is 580.47m, and the water level of the lower reservoir is 229.76m, from which the head difference can be analyzed. Pressure sensors can be installed at the volute inlet and the tailwater inlet. When a sudden load occurs, the pressure pulsation signal is continuously recorded to provide raw data for subsequent analysis.

[0108] The pressure pulsation data detected by the sensor is used to obtain the IMF component by using the variational mode decomposition method (VMD), and the IMF component is convolved to obtain the pressure pulsation trend term and pulsation term. For example, through signal mapping calculation, the maximum eigenvalue time node of the trend term of the volute inlet pressure measuring point is 24.79s, and the minimum eigenvalue time node of the trend term of the tailwater inlet pressure measuring point is 22.51s. The 1T, 1.2T, 1.3T...3.0T cycles are taken respectively, and the 97% confidence level of the pressure pulsation peak-to-peak value in each cycle is calculated. It can be seen that the pressure pulsation peak-to-peak value of the volute inlet pressure measuring point and the tailwater pipe inlet pressure measuring point changes smoothly at different time lengths, and the average value is taken as the final pressure pulsation peak-to-peak value. According to the actual measurement on site, this result is more accurate than the pressure pulsation peak-to-peak value calculated at a single time length.

[0109] Therefore, the method according to the embodiment of the present disclosure uses the variational modal decomposition technology to decompose the pressure signal at the target position of the hydropower station unit to obtain the trend term and the pulsation term; and calculates the peak-to-peak value of the pulsation term under different cycle lengths through signal mapping, thereby obtaining the peak-to-peak value of the pressure pulsation. The accuracy of the peak-to-peak value detection of the pressure pulsation under transient conditions is improved, and a reasonable and accurate technical support is provided for the analysis of related pressure data.

[0110] It should be noted that the method of the embodiment of the present disclosure can be performed by a single device, such as a computer or a server. The method of the present embodiment can also be applied in a distributed scenario and completed by multiple devices cooperating with each other. In the case of such a distributed scenario, one of the multiple devices can only perform one or more steps in the method of the embodiment of the present disclosure, and the multiple devices will interact with each other to complete the described method.

[0111] It should be noted that the above describes some embodiments of the present disclosure. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the above embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0112] Based on the same technical concept, corresponding to any of the above-mentioned embodiments, the present disclosure also provides a detection device for the peak-to-peak value of pressure pulsation of a hydropower station unit under transient conditions, see Figure 5 The detection device for the peak-to-peak value of the pressure pulsation of the hydropower station unit under the transient working condition comprises:

[0113] An acquisition module, used for acquiring a pressure pulsation signal at a preset position in a unit of the hydropower station;

[0114] A decomposition module, used for decomposing the pressure pulsation signal to obtain corresponding trend item signals and pulsation item signals;

[0115] A mapping module, used for performing signal mapping processing on the trend item signal and the pulsation item signal to obtain the peak-to-peak value of the pulsation item under different cycle lengths;

[0116] The mean value module is used to calculate the average value of the peak-to-peak value of the pulsation item under different cycle lengths to obtain the peak-to-peak value of the pressure pulsation at the preset position.

[0117] For the convenience of description, the above device is described by dividing it into various modules according to its functions. Of course, when implementing the present disclosure, the functions of each module can be implemented in the same or multiple software and / or hardware.

[0118] In some embodiments, the pressure pulsation signal is decomposed to obtain corresponding trend item signals and pulsation item signals, including:

[0119] Decomposing the pressure pulsation signal into a plurality of intrinsic mode function components;

[0120] Convolution and local feature extraction are performed on each of the intrinsic mode function components to obtain the trend term signal and the pulsation term signal.

[0121] In some embodiments, performing convolution and local feature extraction on each of the intrinsic mode function components to obtain the trend term signal and the pulsation term signal includes:

[0122] Extracting the low-frequency part of the intrinsic mode function component to obtain the trend term signal;

[0123] The high frequency part of the intrinsic mode function component is extracted to obtain the pulsation term signal.

[0124] In some embodiments, performing signal mapping processing on the trend item signal and the pulsation item signal to obtain the peak-to-peak value of the pulsation item at different cycle lengths includes:

[0125] Determine a first time node corresponding to a maximum eigenvalue and a second time node corresponding to a minimum eigenvalue in the trend item;

[0126] Determine at least one cycle length based on the first time node and / or the second time node;

[0127] For each cycle length, the peak-to-peak value of the pulsation term is obtained based on the difference between the maximum value and the minimum value time of the pulsation term within the cycle length.

[0128] In some embodiments, determining a first time node corresponding to a maximum eigenvalue and a second time node corresponding to a minimum eigenvalue in the trend item includes:

[0129] Based on the time node in the trend item time chain table pointed to by the first pointer of the maximum eigenvalue, obtaining the first time node;

[0130] Based on the time node in the trend item time linked list pointed to by the second pointer of the minimum eigenvalue, the second time node is obtained.

[0131] In some embodiments, calculating the average of the peak-to-peak values ​​of the pulsation terms at different cycle lengths comprises:

[0132] Wherein, A is the average value, n is the number of different cycle lengths, and k is the sequence number of the cycle length.

[0133] In some embodiments, calculating the average value of the peak-to-peak value of the pulsation term at different cycle lengths further includes:

[0134] Calculating the confidence level of the peak-to-peak value of the pulsation item corresponding to each cycle length;

[0135] The average value is calculated based on the peak-to-peak value of the pulsation item corresponding to the confidence level being greater than or equal to the confidence level threshold.

[0136] The device of the above embodiment is used to implement the method for detecting the peak-to-peak value of the pressure pulsation of the hydropower station unit under the corresponding transient conditions in any of the above embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0137] Based on the same technical concept, corresponding to any of the above-mentioned embodiment methods, the present disclosure also provides a non-transient computer-readable storage medium, wherein the non-transient computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute the method for detecting the peak-to-peak value of the pressure pulsation of a hydropower station unit under transient conditions as described in any of the above embodiments.

[0138] The computer-readable medium of this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, read-only compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device.

[0139] The computer instructions stored in the storage medium of the above embodiment are used to enable the computer to execute the method for detecting the peak-to-peak value of the pressure pulsation of the hydropower station unit under transient conditions as described in any of the above embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0140] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present disclosure (including the claims) is limited to these examples. Based on the concept of the present disclosure, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present disclosure as described above, which are not provided in detail for the sake of simplicity.

[0141] In addition, to simplify the description and discussion, and in order not to make the embodiments of the present disclosure difficult to understand, the known power / ground connections to the integrated circuit (IC) chips and other components may or may not be shown in the provided figures. In addition, the device can be shown in the form of a block diagram to avoid making the embodiments of the present disclosure difficult to understand, and this also takes into account the fact that the details of the implementation of these block diagram devices are highly dependent on the platform on which the embodiments of the present disclosure will be implemented (that is, these details should be fully within the scope of understanding of those skilled in the art). Where specific details (e.g., circuits) are set forth to describe exemplary embodiments of the present disclosure, it is apparent to those skilled in the art that the embodiments of the present disclosure can be implemented without these specific details or with changes in these specific details. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0142] Although the present disclosure has been described in conjunction with specific embodiments of the present disclosure, many replacements, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may use the embodiments discussed.

[0143] The embodiments of the present disclosure are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A method for detecting the peak-to-peak value of pressure pulsation of a hydropower station unit under transient conditions, characterized in that: include: Acquiring a pressure pulsation signal at a preset position in the hydropower station unit; Decomposing the pressure pulsation signal to obtain corresponding trend item signal and pulsation item signal; Performing signal mapping processing on the trend item signal and the pulsation item signal to obtain the peak-to-peak value of the pulsation item under different cycle lengths; The average value of the peak-to-peak value of the pulsation item at different cycle lengths is calculated to obtain the peak-to-peak value of the pressure pulsation at the preset position.

2. The method according to claim 1, characterized in that Decomposing the pressure pulsation signal to obtain corresponding trend term signals and pulsation term signals includes: Decomposing the pressure pulsation signal into a plurality of intrinsic mode function components; Convolution and local feature extraction are performed on each of the intrinsic mode function components to obtain the trend term signal and the pulsation term signal.

3. The method according to claim 2, characterized in that Convolution and local feature extraction are performed on each of the intrinsic mode function components to obtain the trend term signal and the pulsation term signal, including: Extracting the low-frequency part of the intrinsic mode function component to obtain the trend term signal; The high frequency part of the intrinsic mode function component is extracted to obtain the pulsation term signal.

4. The method according to claim 1, characterized in that The trend item signal and the pulsation item signal are subjected to signal mapping processing to obtain the peak-to-peak value of the pulsation item at different cycle lengths, including: Determine a first time node corresponding to a maximum eigenvalue and a second time node corresponding to a minimum eigenvalue in the trend item; Determine at least one cycle length based on the first time node and / or the second time node; For each cycle length, the peak-to-peak value of the pulsation term is obtained based on the difference between the maximum value and the minimum value time of the pulsation term within the cycle length.

5. The method according to claim 4, characterized in that Determining a first time node corresponding to a maximum eigenvalue and a second time node corresponding to a minimum eigenvalue in the trend item includes: Based on the time node in the trend item time chain table pointed to by the first pointer of the maximum eigenvalue, obtaining the first time node; Based on the time node in the trend item time linked list pointed to by the second pointer of the minimum eigenvalue, the second time node is obtained.

6. The method according to claim 4, characterized in that Calculate the average value of the peak-to-peak value of the pulsation term at different cycle lengths, including: Wherein, A is the average value, n is the number of different cycle lengths, and k is the sequence number of the cycle length.

7. The method according to claim 6, characterized in that Calculating the average value of the peak-to-peak value of the pulsation term at different cycle lengths also includes: Calculating the confidence level of the peak-to-peak value of the pulsation item corresponding to each cycle length; The average value is calculated based on the peak-to-peak value of the pulsation item corresponding to the confidence level being greater than or equal to the confidence level threshold.

8. A device for detecting the peak-to-peak value of pressure pulsation of a hydropower station unit under transient conditions, characterized in that: include: An acquisition module, used for acquiring a pressure pulsation signal at a preset position in a unit of the hydropower station; A decomposition module, used for decomposing the pressure pulsation signal to obtain corresponding trend item signals and pulsation item signals; A mapping module, used for performing signal mapping processing on the trend item signal and the pulsation item signal to obtain the peak-to-peak value of the pulsation item under different cycle lengths; The mean value module is used to calculate the average value of the peak-to-peak value of the pulsation item under different cycle lengths to obtain the peak-to-peak value of the pressure pulsation at the preset position.

9. The device according to claim 8, characterized in that Decomposing the pressure pulsation signal to obtain corresponding trend term signals and pulsation term signals includes: Decomposing the pressure pulsation signal into a plurality of intrinsic mode function components; Convolution and local feature extraction are performed on each of the intrinsic mode function components to obtain the trend term signal and the pulsation term signal.

10. The device according to claim 9, characterized in that Convolution and local feature extraction are performed on each of the intrinsic mode function components to obtain the trend term signal and the pulsation term signal, including: Extracting the low-frequency part of the intrinsic mode function component to obtain the trend term signal; The high frequency part of the intrinsic mode function component is extracted to obtain the pulsation term signal.

11. The device according to claim 8, characterized in that The trend item signal and the pulsation item signal are subjected to signal mapping processing to obtain the peak-to-peak value of the pulsation item at different cycle lengths, including: Determine a first time node corresponding to a maximum eigenvalue and a second time node corresponding to a minimum eigenvalue in the trend item; Determine at least one cycle length based on the first time node and / or the second time node; For each cycle length, the peak-to-peak value of the pulsation term is obtained based on the difference between the maximum value and the minimum value time of the pulsation term within the cycle length.

12. The device according to claim 11, characterized in that Determining a first time node corresponding to a maximum eigenvalue and a second time node corresponding to a minimum eigenvalue in the trend item includes: Based on the time node in the trend item time chain table pointed to by the first pointer of the maximum eigenvalue, obtaining the first time node; Based on the time node in the trend item time linked list pointed to by the second pointer of the minimum eigenvalue, the second time node is obtained.

13. The device according to claim 11, characterized in that Calculate the average value of the peak-to-peak value of the pulsation term at different cycle lengths, including: Wherein, A is the average value, n is the number of different cycle lengths, and k is the sequence number of the cycle length.

14. The device according to claim 13, characterized in that Calculating the average value of the peak-to-peak value of the pulsation term at different cycle lengths also includes: Calculating the confidence level of the peak-to-peak value of the pulsation item corresponding to each cycle length; The average value is calculated based on the peak-to-peak value of the pulsation item corresponding to the confidence level being greater than or equal to the confidence level threshold.

15. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method according to any one of claims 1 to 7 when executing the program. 16 . A non-transitory computer-readable storage medium storing computer instructions, wherein the computer instructions are used to cause a computer to execute the method according to claim 1 .

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