Fault recording data processing method and device, equipment and storage medium

Abstract

The embodiment of the invention provides a fault recording data processing method and device, equipment and a storage medium, and relates to the technical field of electric power. The method comprises the steps of obtaining a wave recording file of a photovoltaic grid-connected point in a preset time period, carrying out data sampling on the wave recording file according to a time period of sampling frequency determined according to the time period of sampling time so as to obtain fault wave recording data, and finally carrying out fault analysis on a power grid fault according to the fault wave recording data. Wherein the time period comprises a fault occurrence stage, a fault development stage or a fault change stage. According to the method, on the premise of ensuring that key fault information is obtained, the data storage amount is effectively reduced, the balance of high sampling rate and low occupied memory of the fault recording data is realized, then a reliable basis is provided for power grid fault analysis, the comprehensiveness and accuracy of power grid fault analysis are greatly improved, and the method is suitable for popularization and application. And safe and stable operation of the low-voltage power grid after distributed photovoltaic large-scale access is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric power, and in particular to a fault recording data processing method and device, equipment and a storage medium. BACKGROUND

[0002] A large number of distributed photovoltaic power is connected to a low-voltage power grid, and when a fault occurs in the power grid, the output power of the photovoltaic inverter presents the characteristics of rapid change and long duration. In order to accurately capture the fault information of the power grid, high-quality fault recording data must meet the requirements of high sampling rate and long delay.

[0003] At present, the recording device generally adopts a fixed sampling frequency sampling mode. First, a high sampling frequency (such as 6400 Hz) is used for fault recording data sampling, and at this time, the fault recording data obtained has high quality but occupies a large memory. Since the carrier communication bandwidth of the distribution network is narrow, it is impossible to complete the data transmission of large capacity. Then, the sampling frequency is reduced (such as 800 Hz) to reduce the occupied memory of the fault recording data. However, at this time, the fault recording data obtained can only analyze the effective value and peak value of the current and voltage, and cannot analyze the transient change process when the power grid is short-circuited, that is, high-quality fault recording data cannot be effectively obtained, and thus the fault analysis of the power grid fault is not accurate.

[0004] To sum up, it is a technical problem to be solved to provide a fault recording data processing method and to improve the accuracy of power grid fault analysis. SUMMARY

[0005] The embodiments of the present application provide a fault recording data processing method, device, equipment and storage medium, so as to achieve the technical effect of improving the accuracy of power grid fault analysis.

[0006] In a first aspect, the embodiments of the present application provide a fault recording data processing method, comprising:

[0007] Obtaining a recording file of a photovoltaic grid-connected point in a preset time period;

[0008] When the recording file is data-sampled, a sampling frequency is determined according to a time period in which a sampling time is located, and data sampling is performed according to a time period in which the sampling frequency is located, so as to obtain fault recording data, the time period including a fault occurrence stage, a fault development stage or a fault change stage;

[0009] According to the fault recording data, a fault analysis of the power grid fault is performed.

[0010] In a possible implementation manner, the sampling frequency is determined according to the time period in which the sampling time is located, comprising:

[0011] determine the sampling frequency corresponding to the sampling time according to the sampling time and a preset sampling frequency determination rule;

[0012] The sampling frequency determination rule comprises:

[0013] determine whether there is a harmonic in a first time period from a starting position in the recording file;

[0014] if there is a harmonic in the first time period, use a first sampling frequency to sample data in the first time period;

[0015] use a second sampling frequency to sample data in a second time period, the second time period being a time period after the first time period and continuous with the first time period;

[0016] determine whether a change amount of current amplitude, a change amount of voltage amplitude or a voltage frequency in a third time period in the recording file exceeds a threshold value, the third time period being a time period after the second time period and continuous with the second time period;

[0017] if at least one of the change amount of current amplitude, the change amount of voltage amplitude or the voltage frequency in the third time period exceeds the threshold value, use a third sampling frequency to sample data in the third time period;

[0018] if the change amount of current amplitude, the change amount of voltage amplitude and the voltage frequency in the recording file all do not exceed the threshold value after the third time period, end the sampling;

[0019] The first sampling frequency is greater than the second sampling frequency, and the second sampling frequency is greater than the third sampling frequency.

[0020] In a possible implementation, the sampling frequency determination rule further comprises:

[0021] if the change amount of current amplitude, the change amount of voltage amplitude and the voltage frequency in the third time period all do not exceed the threshold value, use a fourth sampling frequency to sample data in the third time period;

[0022] The fourth sampling frequency is less than the third sampling frequency.

[0023] In a possible implementation, the sampling frequency determination rule further comprises:

[0024] if at least one of the change amount of current amplitude, the change amount of voltage amplitude or the voltage frequency in the recording file exceeds the threshold value in a fourth time period after the third time period and continuous with the third time period, use a fifth sampling frequency to sample data in the fourth time period.

[0025] The fifth sampling frequency is less than or equal to the fourth sampling frequency.

[0026] In a possible implementation, the sampling frequency rule further includes:

[0027] If there is no harmonic in the first time period, a sixth sampling frequency is used for data sampling in the first time period.

[0028] The sixth sampling frequency is less than the first sampling frequency, and the sixth sampling frequency is greater than or equal to the second sampling frequency.

[0029] In a possible implementation, the third time period is longer than the second time period, and the second time period is longer than the first time period.

[0030] In a possible implementation, the fourth time period is longer than the third time period.

[0031] In a second aspect, an embodiment of the present application provides a fault recording data processing device, including:

[0032] A first processing module is configured to acquire a recording file of a photovoltaic grid-connected point in a preset time period.

[0033] A second processing module is configured to determine a sampling frequency according to a time period in which a sampling time is located when data sampling is performed on the recording file, and perform data sampling according to a time period in which the sampling frequency is located to obtain fault recording data, the time period including a fault occurrence stage, a fault development stage, or a fault change stage.

[0034] A third processing module is configured to perform fault analysis on a power grid fault according to the fault recording data.

[0035] In a third aspect, an embodiment of the present application provides an electronic device, including a memory and a processor.

[0036] The memory stores computer execution instructions.

[0037] The processor executes the computer execution instructions stored in the memory, so that the processor executes the first aspect and / or various possible implementation manners of the first aspect.

[0038] In a fourth aspect, an embodiment of the present application provides a computer readable storage medium, the computer readable storage medium stores computer execution instructions, and the computer execution instructions are executed by a processor to implement the first aspect and / or various possible implementation manners of the first aspect.

[0039] The embodiment of the present application provides a fault recording data processing method, device, equipment and storage medium, the fault recording data processing method comprises the following steps: acquiring a recording file of a photovoltaic grid-connected point in a preset time period; sampling data in a time period of a sampling frequency of the recording file according to a time period in which the sampling time is located; obtaining fault recording data; and performing fault analysis on a power grid fault according to the fault recording data. The time period comprises a fault occurrence stage, a fault development stage or a fault change stage. Through the above method, the data storage amount is effectively reduced under the premise of ensuring that key fault information is acquired, the balance between high sampling rate of fault recording data and low memory occupation is realized, and then a reliable basis is provided for power grid fault analysis, the comprehensiveness and accuracy of power grid fault analysis are greatly improved, and the safe and stable operation of a low-voltage power grid after large-scale access of distributed photovoltaics is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0040] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate embodiments consistent with the present application and, together with the description, further serve to explain the principles of the application.

[0041] Figure 1 A flowchart of a fault recording data processing method provided by the present application Figure 1 ;

[0042] Figure 2 A flowchart of a fault recording data processing method provided by the present application Figure 2 ;

[0043] Figure 3 A structural diagram of a fault recording data processing device provided by the present application

[0044] Figure 4 A structural diagram of an electronic device provided by the present application.

[0045] Through the above drawings, the specific embodiments of the present application have been shown, and more detailed descriptions will be given hereinafter. These drawings and the written description are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0046] The exemplary embodiments will be described in detail herein with reference to the drawings. Unless otherwise specified, the same numbers in different drawings indicate the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of devices and methods consistent with some aspects of the present application, as detailed in the appended claims.

[0047] The application background of the present application is explained as follows:

[0048] With the growing demand for clean energy and the promotion of the "double carbon" target, distributed photovoltaic power generation has an increasing share in the energy structure due to its advantages of being clean, renewable, flexible in form, and low in management and operation cost. In particular, in the field of low-voltage power grids, the scale of distributed photovoltaic access continues to expand. When the power grid fails, such as entering an isolated network operation state, the output power of the photovoltaic inverter exhibits characteristics of rapid change and long duration. In order to accurately analyze the causes of power grid failure, assess the impact of failure on power grid equipment and system operation, and develop effective failure response strategies, accurate and detailed fault recording data is needed.

[0049] Currently, recording devices generally use a fixed sampling frequency sampling method. Taking a common 50Hz power grid as an example, when high-quality fault recording data is needed, the data sampling frequency of the photovoltaic grid-connected point alternating voltage and current can be set to a high value, such as 6400Hz, i.e. 6400 data are collected per second, and 128 groups of data are collected per cycle. However, when long-delay data of minutes are needed to be recorded, the storage capacity of the obtained fault recording data is large, occupying a large amount of memory. However, due to the narrow bandwidth of the carrier communication of the distribution network, it is not possible to complete the uploading of large-capacity data. In order to reduce the memory occupied by the fault recording data, the data sampling frequency of the photovoltaic grid-connected point alternating voltage and current is reduced to 800Hz, i.e. 800 data are collected per second, and 16 groups of data are collected per cycle. However, at this time, the obtained fault recording data is prone to lose high-frequency signal details due to the low sampling frequency, and only the effective value and peak value of the current and voltage can be analyzed, and the transient change process (such as harmonics, voltage sudden drop or sudden rise) of the power grid short circuit cannot be analyzed, i.e. high-quality fault recording data cannot be effectively obtained, and thus the fault analysis of the power grid failure is not accurate.

[0050] In summary, it is a technical problem to be solved to provide a fault recording data processing method and to improve the accuracy of power grid failure analysis.

[0051] Based on the above technical problems, the inventors found that the power grid failure is a dynamic and phased process from occurrence to recovery, and by dividing the acquisition process of the fault recording data into different fault phases and sampling data at different sampling frequencies, the balance between high sampling rate and low memory occupation of the fault recording data can be achieved, and thus the comprehensiveness and accuracy of the power grid failure analysis can be improved. Based on this, the present application provides a fault recording data processing method, device, electronic equipment and storage medium.

[0052] The technical solutions of the present application and how the technical solutions of the present application solve the above technical problems will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes can not be described again in some embodiments. The embodiments of the present application will be described below with reference to the drawings.

[0053] Figure 1 A flowchart of a fault recording data processing method provided by the present application Figure 1 As shown in Figure 1 , the method comprises:

[0054] S101: Obtain the recording file of the photovoltaic grid-connected point in a preset time period.

[0055] In this step, the photovoltaic grid-connected point refers to the node where the distributed photovoltaic power generation system is electrically connected to the low-voltage power grid, which is the key position of the power generated by photovoltaic power output into the public power grid. The preset time period refers to the whole process from the occurrence of a short circuit, grounding and other faults in the power grid to the action of the protection device to remove the fault source, and then to the recovery of the power grid, which is usually completed within a few seconds. This preset time period can cover the sudden change of electrical quantity (such as voltage drop, current surge) at the moment of fault occurrence, and also can include the steady-state characteristics during the fault duration and the voltage and current recovery process after the fault is removed, thereby providing complete fault timing data for power grid fault analysis. The recording file refers to the file recorded by the recorder, which records the change of voltage, current and other electrical parameters in the power grid with time, which helps technicians understand the operation state of the power grid in different time periods, and thus ensures the safe and reliable operation of the power grid.

[0056] S102: When data sampling is performed on the recording file, the sampling frequency is determined according to the time period in which the sampling time is located, and data sampling is performed according to the time period in which the sampling frequency is located, to obtain fault recording data, the time period including the fault occurrence stage, the fault development stage or the fault change stage.

[0057] In this step, the sampling frequency represents the number of data points collected per unit of time, determining the density and precision of the collected data. The time period is divided into different stages according to the characteristics of the power grid fault process, including the fault occurrence stage, the fault development stage, and the fault change stage. The fault occurrence stage is the moment when the power grid fault occurs from nothing to something, with extremely rapid changes in electrical quantities and containing a large amount of key information. For example, in the moment of short-circuit fault of the power grid, the current may rise several times within a few milliseconds, and the voltage drops rapidly. The fault development stage is the process from the occurrence of the power grid fault to the removal of the fault, during which the electrical quantities are still changing but relatively stable compared to the fault occurrence stage. The fault change stage covers the fault recovery process, during which the voltage and current begin to gradually recover to normal after the protection device acts to remove the fault line or the power grid system adjusts the output. The changes in electrical quantities include both sudden changes (such as the moment of protection action) and gradual changes (such as the process of voltage and current recovery to steady state).

[0058] Specifically, according to the characteristics of the change in electrical quantities in different time periods, different sampling frequencies are used for data sampling. For example, in the fault occurrence stage where the electrical quantities change extremely rapidly and contain a large amount of key information, a higher sampling frequency is used for data sampling. In the fault development stage where the electrical quantities continue to change but are relatively stable, the sampling frequency can be appropriately reduced for data sampling. In the fault change stage, since the electrical quantities contain both sudden changes and gradual changes, the sampling frequency can be dynamically adjusted according to the changes in voltage amplitude, current amplitude, or voltage frequency.

[0059] By using different sampling frequencies for data sampling according to the time period in which the sampling time is located, i.e., the different stages of the fault, the final sampling data is obtained, achieving the balance between high sampling rate and low memory occupation of the fault recording data, and further improving the comprehensiveness and accuracy of the power grid fault analysis, providing strong support for subsequent power grid fault diagnosis and system operation optimization.

[0060] S103: According to the fault recording data, performing fault analysis on the power grid fault.

[0061] In this step, the acquired sampled data is typically presented as a time series. Each data point records parameters such as the voltage amplitude, phase, and current magnitude and phase at the corresponding moment in time at the PV grid connection point. When analyzing a power grid fault, technicians or the analysis system will first preprocess the sampled data, including removing outliers and correcting for time synchronization errors, to ensure data reliability. Subsequently, the fault type is determined by analyzing the characteristics of electrical quantity changes in the sampled data, such as the timing of sudden changes in voltage and current, the magnitude of amplitude changes, and the degree of waveform distortion. For example, a sudden voltage drop and a sudden current surge may indicate a short circuit, while a voltage that remains below the threshold may indicate an undervoltage fault. Furthermore, the timestamp information in the sampled data can be used to precisely determine the time and duration of the fault. This, combined with the grid topology and protection device operation logic, can further pinpoint the fault location. Furthermore, by comparing the electrical quantities before and after the fault in the sampled data, such as the load status before the fault and the parameter changes after the fault, the impact of the fault on the power grid can be assessed, providing a basis for developing fault resolution plans and optimizing the system.

[0062] The quality and integrity of sampling data directly affect the accuracy of power grid fault analysis results and provide a data basis for power grid fault analysis.

[0063] The method for processing fault recording data provided in the embodiment of the present application is to obtain the recording file of the photovoltaic grid-connected point within a preset time period, and then when sampling the recording file, based on the fault occurrence stage, fault development stage or fault change stage at the sampling time, combined with the characteristics of the electrical quantity changes in each stage, adopt differentiated sampling frequencies to perform data sampling and obtain sampled data. Finally, a fault analysis of the power grid fault is performed based on the sampled data. Through the above method, by differential sampling at different sampling frequencies in different stages, while ensuring the acquisition of key fault information, the amount of data storage is effectively reduced, and a balance between high sampling rate and low memory occupancy of fault recording data is achieved, alleviating the problem of large-capacity data transmission caused by insufficient carrier communication bandwidth of the distribution network, thereby providing a reliable basis for power grid fault analysis, greatly improving the comprehensiveness and accuracy of power grid fault analysis, and ensuring the safe and stable operation of the low-voltage power grid after large-scale access of distributed photovoltaics.

[0064] Figure 2 A schematic diagram of a method for processing fault recording data provided in this application Figure 2 ,like Figure 1 As shown, this embodiment Figure 2 Based on the embodiment, S102 determines the sampling frequency according to the time period of the sampling time, specifically including:

[0065] In a possible implementation, the sampling frequency corresponding to the sampling time is determined according to the sampling time and a preset sampling frequency determination rule.

[0066] According to the preset sampling frequency determination rule, the sampling frequency corresponding to the sampling time is determined, which specifically includes the following steps (sampling frequency determination rule):

[0067] S201: Determine whether there is a harmonic in the first time period starting from the starting position in the recording wave file.

[0068] In this step, the harmonic refers to the component of the integer multiple frequency of the fundamental frequency existing in the voltage or current waveform in the power system, which is usually caused by nonlinear loads or devices, such as power electronic devices, frequency converters, computers, electric arc furnaces, and fluorescent lamps, etc. When these devices are working, they cause distortion of the current or voltage waveform, thereby generating harmonics.

[0069] The first time period starting from the sampling starting position is usually accompanied by a dramatic change in electrical parameters, and harmonic detection helps to accurately diagnose the fault type and cause. By timely detecting and analyzing the harmonics in the fault stage, it is a key step to ensure the safe and efficient operation of the power system, which can provide important data support for subsequent system optimization and improvement.

[0070] S202: If there is a harmonic in the first time period, a first sampling frequency is used for data sampling in the first time period.

[0071] In this step, the first time period can be used to indicate the fault occurrence stage of the time period in which the sampling time is located, and the first sampling frequency represents the sampling frequency for data sampling in the fault occurrence stage. The fault occurrence stage is the moment when the power grid fault goes from nothing to something, at which time the electrical quantity such as voltage drops sharply and current surges, changes extremely dramatically and contains a large amount of key information, for example, the current may rise several times in a few milliseconds and the voltage drops rapidly at the moment of short-circuit fault. In order to capture these instantaneous changes, a higher sampling frequency needs to be set to ensure that every subtle fluctuation can be recorded, providing accurate data for fault type judgment and fault point positioning.

[0072] For example, for a common 50Hz power grid, the fault recording wave data of a preset time period of 10s is obtained, and the 50Hz power grid has a cycle of 0.02s. Assuming that the first time period containing 10 cycles starting from the sampling starting position is the fault occurrence stage (0-0.2s), if there is a harmonic in this time period, a first sampling frequency of 6400Hz is used for data sampling, that is, 6400 data are collected per second, 128 groups of data are collected per cycle, and a total of 1280 groups of data are collected.

[0073] S203: A second sampling frequency is used for data sampling in a second time period, and the second time period is a time period after the first time period and continuous with the first time period.

[0074] Wherein, the first sampling frequency is greater than the second sampling frequency.

[0075] In this step, the second time period is a time period after and continuous with the first time period, i.e., the time period is after and continuous with the fault occurrence stage, and thus the second time period can be a fault development stage for indicating a time period in which the sampling time is located, and the second sampling frequency represents a sampling frequency for sampling data in the fault development stage. The electrical quantity in the fault development stage is still continuously changing but is relatively stable compared with the fault occurrence stage, and thus the data sampling frequency of the fault development stage needs to remain high but can be lower than the data sampling frequency of the fault occurrence stage, i.e., the first sampling frequency is greater than the second sampling frequency.

[0076] For example, the second time period is a time period after and continuous with the first time period. Assuming that, after and continuous with the first time period, the second time period corresponding to the fault development stage (0.2-1s) in which 40 cycles are included, the second sampling frequency 1600Hz is used for data sampling, i.e., 1600 pieces of data are collected per second, 32 groups of data are collected per cycle, and a total of 1280 groups of data are collected. The sampling frequency is less than the sampling frequency corresponding to the presence of harmonics in the fault occurrence stage.

[0077] S204: Determine whether the change amount of the current amplitude, the change amount of the voltage amplitude, or the voltage frequency in the third time period in the recording wave file exceeds a threshold value.

[0078] The third time period is a time period after and continuous with the second time period.

[0079] In this step, the third time period is a time period after and continuous with the second time period, i.e., the time period is after and continuous with the fault development stage, and thus the third time period can be a fault change stage for indicating a time period in which the sampling time is located.

[0080] In the fault change stage, if at least one of the change amount of the current amplitude, the change amount of the voltage amplitude, or the voltage frequency exceeds a threshold value, it indicates that the power grid is in a non-steady state process, and data sampling is performed by using a high sampling frequency to accurately record the rising or falling slope of the voltage and current, the overshoot amplitude, the frequency jump moment, and the like, thereby providing a basis for subsequent power grid fault analysis.

[0081] Specifically, the expression that the change amount of the current amplitude exceeds the threshold value is as follows:

[0082]

[0083] wherein k represents a current time, N is a constant, represents current sampling data of the current time, represents current sampling data of the k-N time, represents the change rate of the current sampling data at the current time and the current sampling data at k-N time, and A represents a threshold value for determining whether the current amplitude changes.

[0084] The expression that the change amount of the voltage amplitude exceeds the threshold value is:

[0085]

[0086] wherein k represents the current time, and N is a constant, represents the voltage sampling data at the current time, represents the voltage sampling data at k-N time, represents the change rate of the voltage sampling data at the current time and the voltage sampling data at k-N time, and B represents a threshold value for determining whether the voltage amplitude changes.

[0087] The expression that the voltage frequency exceeds the threshold value is:

[0088] , or

[0089] wherein k represents the current time, represents the voltage frequency at the current time, and f represents the power grid frequency, , N is a constant, represents the voltage frequency at k-N time, represents the difference between the voltage frequency at the current time and the voltage frequency at k-N time.

[0090] S205: If at least one of the change amount of the current amplitude, the change amount of the voltage amplitude, or the voltage frequency exceeds the threshold value in the third time period, data sampling is performed at a third sampling frequency in the third time period.

[0091] wherein the second sampling frequency is greater than the third sampling frequency.

[0092] In this step, as described in S204, in the third time period (fault change stage), if at least one of the change amount of the current amplitude, the change amount of the voltage amplitude, or the voltage frequency exceeds the threshold value, it indicates that the power grid is in a non-steady state process, at which time data sampling is performed by a high sampling frequency to accurately record the rising or falling slope of the voltage and current, the overshoot amplitude, the frequency jump time, etc. The third sampling frequency represents the sampling frequency at which data sampling is performed in the fault change stage.

[0093] For example, it is assumed that in the fault change stage (1-5s) corresponding to the third time period containing 200 cycles after and continuous with the second time period, the change amount of the current amplitude a change in the voltage amplitude (the change in the voltage amplitude exceeds a threshold value), , or a change in the voltage frequency / a change in the voltage frequency exceeds a threshold value, wherein the power grid frequency f = 50 Hz, , the third sampling frequency 50 Hz is used for data sampling, that is, 50 data are collected per second, 1 group of data is collected per cycle, and a total of 200 groups of data are collected. The sampling frequency is less than the corresponding sampling frequency in the fault development stage.

[0094] S206: If the changes in the current amplitude, the voltage amplitude and the voltage frequency do not exceed the threshold values in the third time period, the fourth sampling frequency is used for data sampling in the third time period.

[0095] wherein the fourth sampling frequency is less than the third sampling frequency.

[0096] For example, corresponding to S205, it is assumed that in the third time period (1-5s) corresponding to the fault change stage after the second time period and continuous therewith, the change in the current amplitude (the change in the current amplitude does not exceed a threshold value), and the change in the voltage amplitude (the change in the voltage amplitude does not exceed a threshold value), and the change in the voltage frequency (the change in the voltage frequency does not exceed a threshold value, wherein the power grid frequency f = 50 Hz, ), the fourth sampling frequency 1 Hz is used for data sampling, that is, 1 data is collected per second, 0.02 groups of data are collected per cycle, and a total of 4 groups of data are collected. The sampling frequency is less than the corresponding sampling frequency when at least one of the change in the current amplitude, the change in the voltage amplitude or the change in the voltage frequency exceeds a threshold value.

[0097] S207: Determine whether the changes in the current amplitude, the voltage amplitude or the voltage frequency exceed the threshold values in the time period after the third time period in the recording wave file.

[0098] S208: If the changes in the current amplitude, the voltage amplitude and the voltage frequency do not exceed the threshold values in the recording wave file after the third time period, the sampling is ended.

[0099] In this step, in order to comprehensively capture potential abnormal fluctuations in the fault recovery process and prevent missing key data due to premature ending of sampling, the changes in electrical quantities need to be continuously monitored after the third time period to ensure thorough confirmation of the fault recovery state and accurate assessment of the stability of the power grid operation. Therefore, the time period after the third time period represents the time period after the fault change stage, which can be represented as another stage of fault change.

[0100] For example, assuming that after the third time period and continuous with the third time period, another phase (5-10s) of fault change corresponding to a time period containing 200 cycles, the change amount of the current amplitude (the change amount of the current amplitude does not exceed the threshold value), and the change amount of the voltage amplitude (the change amount of the voltage amplitude does not exceed the threshold value), and the voltage frequency (the voltage frequency does not exceed the threshold value, wherein the power grid frequency f=50Hz, ), then the sampling is ended, and the waveform data of the current and the voltage is no longer recorded, and the fault recording data is obtained.

[0101] S209: If at least one of the change amount of the current amplitude, the change amount of the voltage amplitude or the voltage frequency in the recording wave file exceeds the threshold value in a fourth time period after the third time period and continuous with the third time period, then the fifth sampling frequency is used for data sampling in the fourth time period.

[0102] The fifth sampling frequency is less than or equal to the fourth sampling frequency.

[0103] For example, corresponding to S208, assuming that after the third time period and continuous with the third time period, another phase (5-10s) of fault change corresponding to a time period containing 200 cycles, the change amount of the current amplitude (the change amount of the current amplitude exceeds the threshold value), or the change amount of the voltage amplitude (the change amount of the voltage amplitude exceeds the threshold value), or the voltage frequency / (the voltage frequency exceeds the threshold value, wherein the power grid frequency f=50Hz, ), then the fifth sampling frequency 1Hz is used for data sampling, that is, 1 data is collected per second, 0.02 groups of data are collected per cycle, and a total of 4 groups of data are collected. The sampling frequency is less than or equal to the sampling frequency corresponding to the case that the change amount of the current amplitude, the change amount of the voltage amplitude and the voltage frequency all exceed the threshold value in the fault change phase.

[0104] S210: If there is no harmonic in the first time period, then the sixth sampling frequency is used for data sampling in the first time period.

[0105] The sixth sampling frequency is less than the first sampling frequency, and the sixth sampling frequency is greater than or equal to the second sampling frequency.

[0106] For example, corresponding to S202, it is assumed that the first time period of 10 cycles from the sampling start position is the fault occurrence stage (0-0.2s), and no harmonics exist in the time period. In this case, the sixth sampling frequency 1600 Hz is used for data sampling, that is, 1600 data are collected per second, 32 groups of data are collected per cycle, and a total of 1280 groups of data are collected. The sampling frequency is less than the sampling frequency corresponding to the presence of harmonics in the fault occurrence stage, and is greater than or equal to the sampling frequency corresponding to the fault development stage.

[0107] In a possible implementation, the duration of the third time period is greater than the duration of the second time period, and the duration of the second time period is greater than the duration of the first time period in S201-S210 of the embodiment.

[0108] In a possible implementation, the duration of the fourth time period is greater than the duration of the third time period.

[0109] That is, when the sampling frequency is determined according to the time period in which the sampling time is located, the duration relationship of the fault occurrence stage, the fault development stage, or the fault change stage in the time period satisfies that the duration of the fault change stage is greater than the duration of the fault development stage, the duration of the fault development stage is greater than the duration of the fault occurrence stage, and the duration of another stage of fault change is greater than the duration of the fault change stage.

[0110] This is because in the fault occurrence stage, the problem just occurs, the signal change may be small and not obvious, and therefore a high sampling frequency is needed to capture the early slight change. This stage usually lasts for a short duration because the transition of the power grid from the normal state to the initial fault may be fast. In the fault development stage, the fault characteristics become more obvious, the signal change amplitude increases, and a high sampling frequency is still needed to accurately capture the change. However, because the signal characteristics are already relatively obvious, the sampling frequency can be appropriately reduced. This stage usually lasts for a longer duration than the fault occurrence stage because the performance of the device in this stage may be gradually deteriorating. The fault change stage is the period when the fault characteristics are most obvious, and the signal changes are violent and frequent. Therefore, if at least one of the change amount of the current amplitude, the change amount of the voltage amplitude, or the voltage frequency exceeds the threshold value, a high sampling frequency is maintained to ensure that all key changes are captured. In order to comprehensively capture potential abnormal fluctuations in the fault recovery process, the duration of another stage of fault change is maintained to be greater than the duration of the fault change stage, so as to prevent missing key data due to early termination of sampling. Until the sampling is ended, the fault recording data is obtained. Through the above duration mapping relationship, the state change characteristics and monitoring requirements of the device in different fault stages are reflected.

[0111] It should be noted that the above preset time period, the length of different stages of the fault, the sampling frequency, the change threshold of the current amplitude, the change threshold of the voltage amplitude, and the threshold of the voltage frequency are all exemplary, and are only used to illustrate the embodiments of the present application, and do not constitute a limitation on the scheme of the present application. In actual application, these parameters can be adjusted and optimized according to the specific power grid environment, equipment characteristics and fault type to adapt to different monitoring needs and technical conditions.

[0112] In a specific implementation of the present scheme, taking the common 50Hz power grid and the fault recording data of 10s as an example, the sampling method of fixed sampling frequency in the prior art is adopted, and a total of 64000 groups of fault recording data are obtained. In comparison, the sampling frequency corresponding to the sampling time is determined according to the sampling time and the preset sampling frequency determination rule as described in the embodiment, and a total of 2765 groups of fault recording data are obtained. In addition, when the power grid does not have a fault, a total of 1604 groups of sampling data are obtained. Figure 3

[0113] The processing method of fault recording data provided by the embodiments of the present application adjusts the sampling frequency flexibly according to different time periods in which the sampling time is located, to adapt to different stage characteristics of the power grid fault. Specifically, the method sets different sampling frequencies by identifying the fault occurrence, the fault development, the fault change and another stage of the fault change, to ensure that the key electrical parameter changes can be effectively captured in each stage. In the fault occurrence stage and the fault development stage, high sampling frequency is used for data sampling to ensure the integrity of the data, and in the fault change stage, whether the voltage amplitude change, the current amplitude change and the voltage frequency exceed the threshold are detected as the basis for reducing the sampling frequency to record the data. Through the above method, accurate monitoring in different fault stages is realized, the data acquisition efficiency is optimized, unnecessary data redundancy is reduced, and the complete capture of key fault information is ensured, which not only improves the accuracy and efficiency of fault diagnosis, but also provides reliable data support for the safe and stable operation of the power grid.

[0114] Figure 3 The structure diagram of a fault recording data processing device provided by the present application is shown in FIG. 30, and the fault recording data processing device 30 provided by the present embodiment includes: Figure 4

[0115] The first processing module 301 is configured to obtain a recording file of the photovoltaic grid-connected point in a preset time period.

[0116] ​​The second processing module 302 is configured to determine a sampling frequency according to a time period in which a sampling time is located when data sampling is performed on the recording wave file, and perform data sampling according to a time period in which the sampling frequency is located to obtain fault recording wave data, the time period including a fault occurrence stage, a fault development stage or a fault change stage.

[0117] The third processing module 303 is configured to perform fault analysis on the power grid fault according to the fault recording wave data.

[0118] In a possible implementation, the second processing module 302 is specifically configured to:

[0119] determine the sampling frequency corresponding to the sampling time according to the sampling time and a preset sampling frequency determination rule;

[0120] The sampling frequency determination rule includes:

[0121] determine whether a harmonic exists in a first time period in the recording wave file from a starting position;

[0122] if the harmonic exists in the first time period, perform data sampling in the first time period by using a first sampling frequency;

[0123] perform data sampling in a second time period by using a second sampling frequency, the second time period being a time period after the first time period and continuous with the first time period;

[0124] determine whether a change amount of a current amplitude, a change amount of a voltage amplitude or a voltage frequency in a third time period in the recording wave file exceeds a threshold value, the third time period being a time period after the second time period and continuous with the second time period;

[0125] if at least one of the change amount of the current amplitude, the change amount of the voltage amplitude or the voltage frequency in the third time period exceeds the threshold value, perform data sampling in the third time period by using a third sampling frequency;

[0126] if the change amount of the current amplitude, the change amount of the voltage amplitude and the voltage frequency in the recording wave file all do not exceed the threshold value after the third time period, end the sampling;

[0127] The first sampling frequency is greater than the second sampling frequency, and the second sampling frequency is greater than the third sampling frequency.

[0128] In a possible implementation, the sampling frequency determination rule further includes:

[0129] if the change amount of the current amplitude, the change amount of the voltage amplitude and the voltage frequency in the third time period all do not exceed the threshold value, perform data sampling in the third time period by using a fourth sampling frequency;

[0130] The fourth sampling frequency is less than the third sampling frequency.

[0131] In a possible implementation, the sampling frequency determination rule further includes:

[0132] If at least one of the change amount of the current amplitude, the change amount of the voltage amplitude or the voltage frequency in the recording wave file exceeds the threshold value in a fourth time period after and continuous with the third time period, a fifth sampling frequency is used for data sampling in the fourth time period;

[0133] The fifth sampling frequency is less than or equal to the fourth sampling frequency.

[0134] In a possible implementation, the sampling frequency rule further includes:

[0135] If there is no harmonic in the first time period, a sixth sampling frequency is used for data sampling in the first time period;

[0136] The sixth sampling frequency is less than the first sampling frequency, and the sixth sampling frequency is greater than or equal to the second sampling frequency.

[0137] In a possible implementation, the length of the third time period is greater than the length of the second time period, and the length of the second time period is greater than the length of the first time period.

[0138] In a possible implementation, the length of the fourth time period is greater than the length of the third time period.

[0139] The processing device for fault recording wave data provided in this embodiment can execute the method provided in the method embodiment, and has similar implementation principles and technical effects, which will not be described here again in this embodiment.

[0140] Figure 4 A structural schematic diagram of an electronic device provided in this application is shown in FIG. 1. ​ As shown in FIG. 1, the electronic device 40 provided in this embodiment includes at least one processor 401 and a memory 402. Optionally, the device 40 further includes a communication component 403. The processor 401, the memory 402 and the communication component 403 are connected through a bus 404.

[0141] In the specific implementation process, the at least one processor 401 executes the computer execution instructions stored in the memory 402, so that the at least one processor 401 executes the above-mentioned method.

[0142] The specific implementation process of the processor 401 can refer to the method embodiment, which has similar implementation principles and technical effects, which will not be described here again in this embodiment.

[0143] In the above embodiments, it should be understood that the processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. A general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the present invention may be directly implemented by a hardware processor or implemented by a combination of hardware and software modules in the processor.

[0144] The memory may include random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage.

[0145] A bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. Buses can be categorized as address buses, data buses, and control buses. For ease of illustration, the buses in the figures of this application are not limited to just one bus or just one type of bus.

[0146] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When a processor executes the computer-executable instructions, the above method is implemented.

[0147] The above-mentioned readable storage medium can be realized by any type of volatile or nonvolatile storage devices or a combination thereof, such as Static Random-Access Memory (SRAM), Electrically Erasable Programmable Read Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk or optical disk. The readable storage medium can be any available medium that can be accessed by a general or special purpose computer.

[0148] An exemplary readable storage medium is coupled to the processor, so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be an integral part of the processor. The processor and the readable storage medium can be located in an Application Specific Integrated Circuit (ASIC). Of course, the processor and the readable storage medium can also exist as discrete components in the device.

[0149] The division of units is only a logical functional division, and in actual implementation, there can be another division manner, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0150] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on multiple network units. According to actual needs, part or all of the units can be selected to achieve the purpose of the embodiment scheme.

[0151] In addition, the functional units in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit.

[0152] If the functions are implemented in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the parts of the technical solutions that essentially contribute to the prior art can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the embodiments of the method of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0153] It can be understood by those skilled in the art that all or part of the steps of the above-mentioned method embodiments can be completed by program instruction related hardware. The aforementioned program can be stored in a computer readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk, and various media that can store program codes.

[0154] Finally, it should be noted that: those skilled in the art will easily derive other embodiments of the present application after considering the specification and practicing the application disclosed herein. The present application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of the present application and include common knowledge or conventional technical means in the art that are not disclosed in the present application, and is not limited to the precise structure described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the present application is only limited by the appended claims.

Claims

1. A method for processing fault recording data, characterized in that: The method comprises: Obtain the recording files of the photovoltaic grid-connected points within the preset time period; When sampling the recorded waveform file, a sampling frequency is determined according to the time period of the sampling time, and data sampling is performed according to the time period of the sampling frequency to obtain fault recorded waveform data, wherein the time period includes a fault occurrence stage, a fault development stage, or a fault change stage; A fault analysis of the power grid fault is performed based on the fault recording data.

2. The method according to claim 1, characterized in that Determining the sampling frequency according to the time period of the sampling time includes: Determine the sampling frequency corresponding to the sampling time according to the sampling time and a preset sampling frequency determination rule; The sampling frequency determination rules include: Determine whether there are harmonics in the first time period starting from the starting position in the recording file; If harmonics exist in the first time period, data sampling is performed using a first sampling frequency in the first time period; Performing data sampling using a second sampling frequency in a second time period, where the second time period is a time period that is subsequent to and continuous with the first time period; Determining whether a change in current amplitude, a change in voltage amplitude, or a voltage frequency within a third time period in the recorded file exceeds a threshold, wherein the third time period is a time period after the second time period and continuous with the second time period; If at least one of the change in current amplitude, the change in voltage amplitude, or the voltage frequency within the third time period exceeds a threshold, data sampling is performed using a third sampling frequency within the third time period; If after the third time period, the change in the current amplitude, the change in the voltage amplitude, and the voltage frequency in the recorded file do not exceed the threshold, then the sampling is terminated; The first sampling frequency is greater than the second sampling frequency, and the second sampling frequency is greater than the third sampling frequency.

3. The method according to claim 2, characterized in that The sampling frequency determination rule also includes: If the change in current amplitude, the change in voltage amplitude, and the voltage frequency within the third time period do not exceed the threshold, data sampling is performed using a fourth sampling frequency within the third time period; The fourth sampling frequency is lower than the third sampling frequency.

4. The method according to claim 3, characterized in that The sampling frequency determination rule also includes: If, in a fourth time period that is subsequent to the third time period and continuous with the third time period, at least one of the change in current amplitude, the change in voltage amplitude, or the voltage frequency in the recorded file exceeds a threshold, data sampling is performed using a fifth sampling frequency in the fourth time period; The fifth sampling frequency is less than or equal to the fourth sampling frequency.

5. The method according to any one of claims 2 to 4, characterized in that The sampling frequency rules also include: If no harmonics exist in the first time period, data sampling is performed using a sixth sampling frequency in the first time period; The sixth sampling frequency is less than the first sampling frequency, and the sixth sampling frequency is greater than or equal to the second sampling frequency.

6. The method according to any one of claims 2 to 4, characterized in that The duration of the third time period is longer than that of the second time period, and the duration of the second time period is longer than that of the first time period.

7. The method according to claim 4, characterized in that The duration of the fourth time period is greater than the duration of the third time period.

8. A device for processing fault recording data, characterized in that: include: The first processing module is used to obtain the recording file of the photovoltaic grid-connected point within a preset time period; A second processing module is configured to determine a sampling frequency according to a time period of a sampling time when sampling the waveform file, and to sample data according to the time period of the sampling frequency to obtain fault waveform data, wherein the time period includes a fault occurrence stage, a fault development stage, or a fault change stage; The third processing module is used to perform fault analysis on the power grid fault based on the fault recording data.

9. An electronic device, characterized in that: include: Memory, processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory, so that the processor performs the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 7 when executed by a processor.

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