New energy station broadband oscillation monitoring method and system, storage medium and terminal

Abstract

The embodiment of the invention discloses a new energy station broadband oscillation monitoring method and system, a storage medium and a terminal. The method comprises the following steps: monitoring the active power and three-phase current of a new energy station grid-connected point in real time; obtaining inter-harmonics according to the active power and the three-phase current; performing clustering analysis on the inter-harmonics to determine a plurality of groups of sample clusters with different frequencies; and performing broadband oscillation monitoring according to the number of the plurality of groups of sample clusters with different frequencies. The inter-harmonics are analyzed based on the big data clustering algorithm, the inter-harmonics are divided into sample cluster data with different frequencies, the amplitude and frequency of the inter-harmonics are monitored more comprehensively, and accurate early warning and evaluation of broadband oscillation are achieved based on clustering analysis.

Description

Technical Field

[0001] This invention relates to the field of new energy power generation and grid connection technology, and in particular to a broadband oscillation monitoring method, system, storage medium and terminal for new energy power plants. Background Technology

[0002] With the increasing proportion of new energy sources and power electronic equipment in the power system, broadband resonance caused by their interaction with the grid has become a significant issue affecting the safe and stable operation of the power grid. Since 2012, the Guyuan Wind Farm in North China has experienced multiple broadband oscillations, severely impacting the stable grid connection of the power system. While the "Technical Standard for Measurement Methods and Instruments for Harmonics and Interharmonics in Power Systems and Their Connected Equipment" proposes detection criteria for interharmonics, this standard only allows for a 5Hz frequency interval for interharmonic detection and is only applicable to stable signals, far from meeting the requirements for monitoring broadband oscillations. Summary of the Invention

[0003] Based on this, it is necessary to propose a broadband oscillation monitoring method, system, storage medium, and terminal for new energy power plants to address the above problems.

[0004] A method for monitoring broadband oscillations at renewable energy power plants, the method comprising:

[0005] Real-time monitoring of active power and three-phase current at the grid connection points of new energy power plants.

[0006] Interharmonics are obtained based on the active power and three-phase current.

[0007] Cluster analysis is performed on the interharmonic waves to identify several sample clusters with different frequencies.

[0008] Broadband oscillation monitoring is performed based on the number of sample clusters with different frequencies.

[0009] Specifically, obtaining interharmonics based on the active power and three-phase current includes:

[0010] Obtain the active power within a preset time interval.

[0011] The phase angle change rate is determined based on the active power.

[0012] Determine the comparison between the phase angle change rate and the preset phase angle change rate.

[0013] When the phase angle change rate is greater than the preset phase angle change rate, the three-phase current within the preset time interval is obtained.

[0014] Interharmonics are obtained based on the three-phase currents.

[0015] The determination of the comparison between the phase angle change rate and the preset phase angle change rate further includes:

[0016] When the phase angle change rate is less than or equal to the preset phase angle change rate, the active power and three-phase current are preprocessed to reacquire different active power within the preset time interval.

[0017] Specifically, obtaining the inter-harmonics based on the three-phase current includes:

[0018] The current signal is obtained from the three-phase current.

[0019] The window is determined based on the current signal and noise data.

[0020] Interharmonics are obtained based on the three-phase current within the window.

[0021] Specifically, determining the window based on the current signal and noise data includes:

[0022] according to Define the window, where SNR is the signal-to-noise ratio of the current signal and the noise data.

[0023] Specifically, obtaining inter-harmonics based on three-phase current within the window includes:

[0024] according to Obtain the interharmonics, where W0 is the synchronization frequency; W i φ0 is the broadband resonant frequency; φ0 is the initial phase angle of the fundamental signal of the three-phase current; φ i Let be the initial phase angle of the broadband resonance of the three-phase current, A be the fundamental amplitude, M be the extreme value, and i be the number of interharmonics.

[0025] Specifically, the broadband oscillation monitoring based on the plurality of sample clusters with different frequencies includes:

[0026] The several groups of sample clusters with different frequencies include the fundamental frequency, the zeroth harmonic, and the first harmonic.

[0027] The number of samples within the several groups of sample clusters with different frequencies is determined by counting the peak values ​​of the fundamental wave, the zeroth harmonic, and the first harmonic.

[0028] Based on the number of samples, the number of the first high-frequency cluster and the number of the second high-frequency cluster are determined by sorting the several groups of sample clusters with different frequencies.

[0029] Determine the comparison between the ratio of the first high cluster number and the second high cluster number and the preset number ratio.

[0030] When the ratio of the number of the first high-cluster clusters to the number of the second high-cluster clusters is greater than the preset cluster number ratio, broadband oscillation occurs.

[0031] The comparison between determining the ratio of the first high cluster number and the second high cluster number and the preset cluster number ratio further includes:

[0032] When the ratio of the first high cluster number to the second high cluster number is less than or equal to the preset cluster number ratio, wideband oscillation does not occur.

[0033] A broadband oscillation monitoring system for new energy power plants, the system comprising:

[0034] The active power and three-phase current monitoring module is used to monitor the active power and three-phase current at the grid connection point of new energy power plants in real time.

[0035] The interharmonic acquisition module is used to acquire interharmonics based on the active power and three-phase current.

[0036] The sample cluster acquisition module is used to perform cluster analysis on the interharmonics to determine several sample clusters with different frequencies.

[0037] A broadband oscillation monitoring module is used to perform broadband oscillation monitoring based on the number of sample clusters with different frequencies.

[0038] The system also includes:

[0039] The waveform recording module is used to connect with the active power and three-phase current monitoring modules to store broadband oscillation monitoring data.

[0040] A storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the method described above.

[0041] A terminal includes a memory and a processor, the memory storing a computer program that, when executed by the processor, causes the processor to perform the steps of the method described above.

[0042] The embodiments of the present invention have the following beneficial effects:

[0043] This invention analyzes interharmonics based on big data clustering algorithms, dividing interharmonics into sample clusters with different frequencies, enabling more comprehensive monitoring of the amplitude and frequency of interharmonics, and achieving accurate early warning and assessment of broadband resonances based on clustering analysis. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] in:

[0046] Figure 1 This is a flowchart illustrating an embodiment of the broadband oscillation monitoring method for new energy power stations provided by the present invention;

[0047] Figure 2 This is a flowchart illustrating another embodiment of the broadband oscillation monitoring method for new energy power stations provided by the present invention;

[0048] Figure 3 This is a schematic diagram of an embodiment of the broadband oscillation monitoring system for new energy power stations provided by the present invention;

[0049] Figure 4 This is a schematic diagram of another embodiment of the broadband oscillation monitoring system for new energy power stations provided by the present invention;

[0050] Figure 5 This is a schematic diagram of the structure of an embodiment of the terminal provided by the present invention;

[0051] Figure 6 This is a schematic diagram of the structure of an embodiment of the medium provided by the present invention. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] like Figure 1 As shown, Figure 1 This is a flowchart illustrating an embodiment of the broadband oscillation monitoring method for new energy power plants provided by the present invention. A broadband oscillation monitoring method for new energy power plants includes:

[0054] S101: Real-time monitoring of active power and three-phase current at the grid connection point of new energy power plants.

[0055] Preferably, the active power and three-phase current of the new energy power station grid connection point are collected in real time at high speed by the monitoring terminal, and the high-speed collection speed of the monitoring terminal includes 12.8 Hz / s and 25.6 Hz / s.

[0056] S102: Obtain interharmonics based on active power and three-phase current.

[0057] In one implementation scenario, the active power within a preset time interval is obtained, the phase angle change rate is determined based on the active power, and the comparison between the phase angle change rate and the preset phase angle change rate is determined. When the phase angle change rate is greater than the preset phase angle change rate, the three-phase current within the preset time interval is obtained, the current signal is obtained based on the three-phase current, the window is determined based on the current signal and noise data, and the interharmonics are obtained based on the three-phase current within the window.

[0058] Specifically, the preset time interval is 20ms. The active power at the grid connection point is counted every 20ms to determine the rate of change of active power. The phase angle change rate is determined based on the rate of change of active power, and the phase angle change rate is determined according to the following formula:

[0059]

[0060]

[0061]

[0062] Where Δθ is the rate of change of phase angle, Δp is the change in active power, and Δt is the change in time.

[0063] When the phase angle change rate is less than or equal to the preset phase angle change rate, the active power and three-phase current are preprocessed to reacquire different active power within the preset time interval.

[0064] When the phase angle change rate is greater than the preset phase angle change rate, the three-phase current at the grid connection point is counted every 20ms. The current signal is obtained based on the three-phase current. The window for extracting inter-harmonics is adaptively determined based on the noise level of the new energy power station using a radial basis neural network. Within the window, a fast Fourier analysis is performed on the three-phase current to extract the inter-harmonics in the range of 0 to 2kHz.

[0065] Preferably, the preset phase angle change rate is 5%.

[0066] Specifically, by refitting the radial basis function neural network with the current signal, the noise data can be obtained, with a signal-to-noise ratio of:

[0067]

[0068] Among them, P s For the current signal power, P n This represents the power of the noise.

[0069] To balance real-time performance and accuracy, a window length is selected when monitoring broadband oscillations at renewable energy power plants. Different window lengths are chosen based on different noise levels, and the selection formula for the window length is as follows:

[0070]

[0071] Furthermore, within a suitable window size, a fast Fourier analysis is performed on the three-phase currents, and the interharmonics are determined according to the following formula:

[0072]

[0073] Where W0 is the synchronization frequency; W i φ0 is the broadband resonant frequency; φ0 is the initial phase angle of the fundamental signal of the three-phase current; φ i Let be the initial phase angle of the broadband resonance of the three-phase current, A be the fundamental amplitude, M be the extreme value, and i be the number of interharmonics.

[0074] S103: Perform cluster analysis on interharmonics to determine several sample clusters with different frequencies.

[0075] In one implementation scenario, the peak values ​​of interharmonic waves are extracted, and cluster analysis is performed on the peak data to identify points with similar characteristics as belonging to the same cluster, thus determining several sample clusters with different frequencies. Specifically, the K-means clustering algorithm is an algorithm based on large datasets that divides samples into several disjoint subsets, using Euclidean distance to measure the similarity of samples. The interharmonic peak data: x1, x2, ..., xn are divided into several centroids, with the mean of each centroid being the centroid of the cluster, as shown in the following formula:

[0076]

[0077] Among them, C i For the central object, μ i Let x be the centroid and x be the peak value of the interharmonic wave.

[0078] Clusters are identified based on their centroids, and then several groups of sample clusters with different frequencies are obtained. The squared error (E) is used to measure the clustering effectiveness; the smaller the E value, the higher the similarity of the data within each cluster. The squared error E is shown in the following formula:

[0079]

[0080] S104: Broadband oscillation monitoring based on the number of sample clusters.

[0081] In one implementation scenario, several sample clusters with different frequencies include the fundamental frequency, the zeroth harmonic, and the first harmonic. The peak counts of the fundamental frequency, the zeroth harmonic, and the first harmonic are counted to determine the sample quantity within each frequency cluster. Based on the sample quantity, the frequency clusters are ranked to determine the first and second highest cluster counts. The ratio of the first and second highest cluster counts is compared to a preset count ratio. When the ratio of the first and second highest cluster counts is greater than the preset count ratio, broadband oscillation occurs. When the ratio of the first and second highest cluster counts is less than or equal to the preset count ratio, broadband oscillation does not occur.

[0082] Preferably, the preset quantity ratio is 5%.

[0083] As described above, this invention analyzes interharmonics based on big data clustering algorithms, divides interharmonics into sample clusters with different frequencies, monitors the amplitude and frequency of interharmonics more comprehensively, and achieves accurate early warning and assessment of broadband resonances based on clustering analysis.

[0084] like Figure 2 and Figure 3 As shown, Figure 2 This is a flowchart illustrating another embodiment of the broadband oscillation monitoring method for new energy power plants provided by the present invention. Figure 3 This is a schematic diagram of an embodiment of the broadband oscillation monitoring system for new energy power plants provided by the present invention. A method for monitoring broadband oscillations in new energy power plants includes:

[0085] S201: Real-time monitoring of active power and three-phase current at the grid connection point of new energy power plants.

[0086] In a specific implementation scenario, combined with Figure 2 and Figure 3 The system monitors and collects active power and three-phase current at the grid-connected points of new energy power plants in real time through monitoring terminals, and transmits the data to the secondary master station via frequency division. The high-speed data acquisition speeds of the monitoring terminals are 12.8 Hz / s and 25.6 Hz / s, and the frequency division transmission cycles are 80 points and 32 points per cycle, respectively.

[0087] S202: Obtain the active power within a preset time interval.

[0088] S203: Determine the phase angle change rate based on the active power.

[0089] In a specific implementation scenario, the active power at the grid connection point is counted every 20ms to determine the rate of change of active power. The phase angle change rate is then determined based on the rate of change of active power, using the formula shown below:

[0090]

[0091]

[0092]

[0093] Where Δθ is the rate of change of phase angle, Δp is the change in active power, and Δt is the change in time.

[0094] S204: Determine the comparison between the phase angle change rate and the preset phase angle change rate.

[0095] S2041: When the phase angle change rate is less than or equal to the preset phase angle change rate, the active power and three-phase current are preprocessed to reacquire different active power within the preset time interval.

[0096] S2042: When the phase angle change rate is greater than the preset phase angle change rate, the three-phase current within the preset time interval is obtained.

[0097] S205: Obtain interharmonics based on three-phase current.

[0098] In a specific implementation scenario, the three-phase current at the grid connection point is counted every 20ms. Based on the three-phase current, the current signal is obtained. The window for extracting inter-harmonics is adaptively determined according to the noise level of the new energy power station based on the radial basis neural network. Within the window, the three-phase current is subjected to fast Fourier analysis to extract the inter-harmonics in the range of 0 to 2kHz.

[0099] Interharmonics are determined according to the following formula:

[0100]

[0101] Where W0 is the synchronization frequency; W i φ0 is the broadband resonant frequency; φ0 is the initial phase angle of the fundamental signal of the three-phase current; φ i Let be the initial phase angle of the broadband resonance of the three-phase current, A be the fundamental amplitude, M be the extreme value, and i be the number of interharmonics.

[0102] S206: Perform cluster analysis on interharmonics to determine several sample clusters with different frequencies.

[0103] S207: Several sample clusters with different frequencies include the fundamental frequency, the zeroth harmonic, and the first harmonic.

[0104] S208: Count the peak values ​​of the fundamental frequency, the zeroth harmonic, and the first harmonic respectively to determine the number of samples in several sample clusters with different frequencies.

[0105] S209: Based on the sample size, sort several groups of sample clusters with different frequencies to determine the number of the first and second highest clusters.

[0106] S210: Determine the comparison between the ratio of the number of the first high cluster and the number of the second high cluster and the preset ratio.

[0107] S211: When the ratio of the number of the first high cluster to the number of the second high cluster is greater than the preset cluster number ratio, a wideband oscillation occurs.

[0108] S212: When the ratio of the number of the first high cluster to the number of the second high cluster is less than or equal to the preset cluster number ratio, wideband oscillation does not occur.

[0109] It should be noted that steps S206-S212 are... Figure 1 The implementation scenarios shown have been discussed in detail and will not be repeated here.

[0110] It should also be noted that steps S202-S212 are performed via... Figure 3 The station-domain storage and analysis device in the secondary master station is shown, and the data is transmitted to the primary master station through other remote transmission equipment. The secondary master station needs to upload the monitoring data, analysis data, and transient data files required by the primary master station, which are then uniformly scheduled and allocated by the primary master station.

[0111] As described above, this invention analyzes interharmonics based on big data clustering algorithms, dividing interharmonics into fundamental, zeroth, and first harmonics, thus more comprehensively monitoring the amplitude and frequency of interharmonics. Furthermore, based on clustering analysis, it achieves accurate early warning and assessment of broadband resonances.

[0112] like Figure 4 As shown, Figure 4 This is a schematic diagram of another embodiment of the broadband oscillation monitoring system for new energy power plants provided by the present invention. A broadband oscillation monitoring system 10 for new energy power plants includes:

[0113] The active power and three-phase current monitoring module 11 is used to monitor the active power and three-phase current at the grid connection point of the new energy power station in real time.

[0114] Interharmonic acquisition module 12 is used to acquire interharmonics based on active power and three-phase current.

[0115] The sample cluster acquisition module 13 is used to perform cluster analysis on interharmonics to determine several sample clusters with different frequencies.

[0116] The broadband oscillation monitoring module 14 is used to perform broadband oscillation monitoring based on the number of sample clusters with different frequencies.

[0117] In a specific implementation scenario, the active power and three-phase current monitoring module 11 monitors and collects the active power and three-phase current at the grid connection point of the new energy power station in real time and at high speed. Further, the interharmonic acquisition module 12 acquires the active power within a preset time interval, determines the phase angle change rate based on the active power, and compares the phase angle change rate with the preset phase angle change rate. When the phase angle change rate is greater than the preset phase angle change rate, the three-phase current at the grid connection point is statistically analyzed every 20ms. Based on the three-phase current, the current signal is acquired, and a window for extracting system interharmonics is adaptively determined based on the noise level of the new energy power station using a radial basis function neural network. Within the window, a fast Fourier analysis is performed on the three-phase current to extract interharmonics in the range of 0 to 2kHz. However, when the phase angle change rate is less than or equal to the preset phase angle change rate, the active power and three-phase current are preprocessed, and different active power values ​​within the preset time interval are acquired again. Further, in the sample cluster acquisition module 13, the peak values ​​of interharmonics are extracted, and cluster analysis is performed on the peak data to identify points with the same characteristics as the same cluster, thus determining several sample clusters with different frequencies. Specifically, the K-means clustering algorithm is an algorithm based on big data to divide samples into several disjoint subsets, using Euclidean distance to measure the similarity of samples, thereby determining several sample clusters with different frequencies. Finally, in the broadband oscillation monitoring module 14, broadband oscillation monitoring is performed based on the number of sample clusters with different frequencies. Specifically, the sample clusters with different frequencies include the fundamental wave, the zeroth harmonic, and the first harmonic. The peak values ​​of the fundamental wave, the zeroth harmonic, and the first harmonic are counted to determine the number of samples within each sample cluster with different frequencies. Based on the number of samples, the sample clusters with different frequencies are sorted to determine the number of the first and second highest clusters. The ratio of the number of the first and second highest clusters is compared with a preset ratio. When the ratio of the number of the first and second highest clusters is greater than the preset ratio, broadband oscillation occurs. When the ratio of the number of the first high-cluster clusters to the number of the second high-cluster clusters is less than or equal to the preset cluster number ratio, broadband oscillation does not occur.

[0118] It should be noted that the broadband oscillation monitoring system 10 for new energy power plants also includes a waveform recording module (not shown in the figure), which is used to connect with the active power and three-phase current monitoring modules to store broadband oscillation monitoring data and has a continuous waveform recording function for 48 hours, which facilitates the subsequent study of broadband resonance data.

[0119] like Figure 5 As shown, Figure 5 This is a schematic diagram of the structure of an embodiment of the terminal provided by the present invention. The terminal 20 includes a memory 21 and a processor 22. The memory 21 stores a computer program, and the processor 22 executes the computer program during operation to achieve, for example, Figure 1 and Figure 2 The method shown.

[0120] The specific technical details of the broadband oscillation monitoring method for new energy power stations implemented by the aforementioned terminal 20 when executing the computer program have been discussed in detail in the above method steps, and therefore will not be repeated here.

[0121] like Figure 6 As shown, Figure 6 This is a schematic diagram of a structure of an embodiment of the storage medium provided by the present invention. The storage medium 30 stores at least one computer program 31, which is executed by the processor 22 to perform the following... Figure 1 and Figure 2 The method shown is detailed above and will not be repeated here. In one embodiment, the storage medium 30 can be a storage chip, hard disk, portable hard disk, USB flash drive, optical disk, or other read / write storage device, or even a server, etc.

[0122] The foregoing has described specific embodiments of this specification; other embodiments are within the scope of the appended claims. In some cases, the actions or steps described in the claims may be performed in a different order than those shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily have to follow the specific or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0123] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the embodiments of apparatus, devices, and non-volatile computer-readable storage media are basically similar to the method embodiments, so the descriptions are relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0124] The apparatus, device, non-volatile computer-readable storage medium and method provided in the embodiments of this specification are corresponding. Therefore, the apparatus, device and non-volatile computer storage medium also have similar beneficial technical effects as the corresponding method. Since the beneficial technical effects of the method have been described in detail above, the beneficial technical effects of the corresponding apparatus, device and non-volatile computer storage medium will not be repeated here.

[0125] The systems, devices, modules, or units described in the above embodiments can be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer. Specifically, a computer can be, for example, a personal computer, laptop computer, cellular phone, camera phone, smartphone, personal digital assistant, media player, navigation device, email device, game console, tablet computer, wearable device, or any combination of these devices.

[0126] For ease of description, the above apparatus is described by dividing it into various functional units. Of course, in implementing this specification, the functions of each unit can be implemented in one or more software and / or hardware components. Those skilled in the art will understand that the embodiments of this specification can be provided as methods, systems, or computer program products. Therefore, the embodiments of this specification can take the form of entirely hardware embodiments, entirely software embodiments, or embodiments combining software and hardware aspects. Furthermore, the embodiments of this specification can take the form of computer program products implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0127] This specification is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this specification. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0128] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0129] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0130] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0131] Memory may include non-persistent storage in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0132] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information 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 technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0133] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0134] This specification can be described in the general context of computer-executable instructions that are executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform a specific task or implement a specific abstract data type. This specification can also be practiced in distributed computing environments, where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0135] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0136] The above description discloses only preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for monitoring broadband oscillations at new energy power plants, characterized in that, The method includes: Real-time monitoring of active power and three-phase current at the grid connection points of new energy power plants; Interharmonics are obtained based on the active power and three-phase current. Cluster analysis is performed on the interharmonic waves to determine several sample clusters with different frequencies; Broadband oscillation monitoring is performed based on the number of sample clusters with different frequencies.

2. The broadband oscillation monitoring method for new energy power stations according to claim 1, characterized in that, The method of obtaining interharmonics based on the active power and three-phase current specifically includes: Obtain the active power within a preset time interval; The phase angle change rate is determined based on the active power. Determine the comparison between the phase angle change rate and the preset phase angle change rate; When the phase angle change rate is greater than the preset phase angle change rate, the three-phase current within the preset time interval is obtained; Interharmonics are obtained based on the three-phase currents.

3. The broadband oscillation monitoring method for new energy power stations according to claim 2, characterized in that, The determination of the comparison between the phase angle change rate and the preset phase angle change rate also includes: When the phase angle change rate is less than or equal to the preset phase angle change rate, the active power and three-phase current are preprocessed to reacquire different active power within the preset time interval.

4. The broadband oscillation monitoring method for new energy power stations according to claim 3, characterized in that, The step of obtaining inter-harmonics based on the three-phase current specifically includes: Obtain the current signal based on the three-phase current; The window is determined based on the current signal and noise data; Interharmonics are obtained based on the three-phase current within the window.

5. The broadband oscillation monitoring method for new energy power stations according to claim 4, characterized in that, The step of determining the window based on the current signal and noise data specifically includes: according to Define the window, where SNR is the signal-to-noise ratio of the current signal and the noise data.

6. The broadband oscillation monitoring method for new energy power stations according to claim 5, characterized in that, The acquisition of inter-harmonics based on the three-phase current within the window specifically includes: according to Obtain the interharmonics, where W0 is the synchronization frequency; W i φ0 is the broadband resonant frequency; φ0 is the initial phase angle of the fundamental signal of the three-phase current; φ i Let be the initial phase angle of the broadband resonance of the three-phase current, A be the fundamental amplitude, M be the extreme value, and i be the number of interharmonics.

7. The broadband oscillation monitoring method for new energy power stations according to claim 6, characterized in that, The broadband oscillation monitoring based on the aforementioned sample clusters with different frequencies specifically includes: The several groups of sample clusters with different frequencies include the fundamental wave, the zeroth harmonic, and the first harmonic; The number of samples within the several groups of samples with different frequencies is determined by counting the peak values ​​of the fundamental wave, the zeroth harmonic, and the first harmonic. Based on the number of samples, the number of the first high cluster and the number of the second high cluster are determined by sorting the several groups of sample clusters with different frequencies. Determine the comparison between the ratio of the number of the first high-cluster clusters and the number of the second high-cluster clusters and the preset ratio; When the ratio of the number of the first high-cluster clusters to the number of the second high-cluster clusters is greater than the preset cluster number ratio, broadband oscillation occurs.

8. The broadband oscillation monitoring method for new energy power stations according to claim 7, characterized in that, The comparison between determining the ratio of the first high cluster number and the second high cluster number and the preset cluster number ratio also includes: When the ratio of the first high cluster number to the second high cluster number is less than or equal to the preset cluster number ratio, wideband oscillation does not occur.

9. A broadband oscillation monitoring system for new energy power stations, characterized in that, The system includes: The active power and three-phase current monitoring module is used to monitor the active power and three-phase current at the grid connection point of new energy power plants in real time. Interharmonic acquisition module, used to acquire interharmonics based on the active power and three-phase current; The sample cluster acquisition module is used to perform cluster analysis on the interharmonics to determine several groups of sample clusters with different frequencies. A broadband oscillation monitoring module is used to perform broadband oscillation monitoring based on the number of sample clusters with different frequencies.

10. A broadband oscillation monitoring system for new energy power stations according to claim 9, characterized in that, The system also includes: The waveform recording module is used to connect with the active power and three-phase current monitoring modules to store broadband oscillation monitoring data.

11. A storage medium, characterized in that, The device stores a computer program that, when executed by a processor, causes the processor to perform the steps of the method as described in any one of claims 1 to 8.

12. A terminal, characterized in that, It includes a memory and a processor, the memory storing a computer program that, when executed by the processor, causes the processor to perform the steps of the method as described in any one of claims 1 to 8.

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