Power grid broadband oscillation multi-oscillation source wide area monitoring method, system, device and medium

Abstract

This invention belongs to the field of power automation and discloses a method, system, equipment, and medium for wide-area monitoring of multiple sources of broadband oscillations in a power grid. The method includes: acquiring the oscillation frequency characteristics of each substation node within a wide area; determining the dominant oscillation frequency of each substation node based on its oscillation frequency characteristics; clustering the dominant oscillation frequencies of each substation node to obtain several oscillation frequency clusters; acquiring the substation nodes covered by each oscillation frequency cluster, obtaining the oscillation range of each oscillation frequency cluster, and within the oscillation range of each oscillation frequency cluster, obtaining the oscillation propagation path and oscillation source of each oscillation frequency cluster based on the oscillation power amplitude of each electrical branch of each substation node. This invention enables wide-area monitoring of multiple sources of broadband oscillations occurring in parallel in a power grid, accurately determining the propagation paths of different oscillation sources, providing support for oscillation source tracing, offering new technical means for power grid operation monitoring, and maintaining power grid operation safety.

Description

Technical Field

[0001] This invention belongs to the field of power automation and relates to a method, system, equipment and medium for wide-area monitoring of multiple oscillation sources in power grid broadband oscillation. Background Technology

[0002] Currently, building a new power system with new energy sources as the mainstay has become a development trend. This new power system emphasizes "new energy" as the core, aiming to significantly increase the proportion of power generation from new energy sources such as photovoltaics and wind power. The core is a high proportion of renewable energy combined with a high proportion of power electronic equipment. Looking at the newly installed capacity of various power sources, the proportion of wind and solar power generation is increasing year by year. The ultimate goal of building a new power system is to achieve decarbonization of the power system.

[0003] However, with the large-scale grid connection of inverters in new power systems, the proportion of power electronic devices will increase significantly, and the entire power system will gradually exhibit a trend towards power electronics, further exacerbating grid oscillation events and causing oscillations to evolve from low-frequency to broadband. This new broadband oscillation is a novel electromagnetic transient oscillation, caused by the interaction between power electronic devices and the grid, as well as between power electronic devices themselves, and does not involve traditional synchronous motors, such as thermal power units and hydropower units. Since the development of new power systems is a long-term process, during this development, both low-frequency and sub-supersynchronous electromechanical transient oscillations from traditional thermal power plants and substations, as well as novel electromagnetic transient oscillations such as sub / supersynchronous and medium-to-high-frequency oscillations, will occur simultaneously. Therefore, achieving wide-area monitoring of multiple oscillation sources has become an urgent problem to be solved.

[0004] In summary, the development and construction of new power systems have promoted the large-scale integration of high-proportion renewable energy sources and the application of high-proportion power electronic equipment, which in turn has brought about a series of new broadband oscillation events. Traditional electromechanical transient oscillations and new electromagnetic transient oscillations in power systems involve different oscillation types. Although real-time monitoring of broadband oscillations has been achieved at the power plant and substation level, at the dispatching master station, due to the simultaneous occurrence of multiple oscillation events with different mechanisms and frequencies, the dispatching master station lacks methods for wide-area monitoring and identification of multiple oscillation sources. It is impossible to differentiate and comprehensively display the propagation paths and impact ranges of different oscillation sources, making it difficult to provide support for the operation monitoring and control of the power grid, thus affecting the operational safety of the power grid. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method, system, device and medium for wide-area monitoring of multiple oscillation sources in power grid broadband oscillation.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] In a first aspect, the present invention provides a method for wide-area monitoring of multiple oscillation sources in a power grid with wide-bandwidth oscillations, comprising:

[0008] Obtain the oscillation frequency characteristics of each plant node within a wide area;

[0009] Based on the oscillation frequency characteristics of each plant node, the dominant oscillation frequency of each plant node is determined.

[0010] Clustering the dominant oscillation frequencies of each plant node yields several oscillation frequency clusters;

[0011] The plant nodes covered by each oscillation frequency cluster are obtained, the oscillation range of each oscillation frequency cluster is obtained, and within the oscillation range of each oscillation frequency cluster, the oscillation propagation path and oscillation source of each oscillation frequency cluster are obtained according to the oscillation power amplitude of each electrical branch of each plant node.

[0012] Optionally, the oscillation frequency characteristics of each plant node within the wide area are transmitted to the dispatch master station in real time by each plant node; the acquisition of the oscillation frequency characteristics of each plant node within the wide area includes: oscillation frequency and oscillation amplitude and oscillation phase of each oscillation frequency; wherein, the oscillation amplitude includes oscillation power amplitude, oscillation voltage amplitude and oscillation current amplitude; the oscillation phase includes oscillation voltage phase and oscillation current phase.

[0013] Optionally, determining the dominant oscillation frequency of each plant node based on its oscillation frequency characteristics includes:

[0014] Based on the oscillation frequency characteristics of each plant node, the oscillation voltage amplitude or oscillation power amplitude of each plant node at each oscillation frequency is obtained.

[0015] For each plant node, the dominant oscillation frequency is selected as either the oscillation frequency with an oscillation voltage amplitude greater than the average oscillation voltage amplitude, or the oscillation frequency with an oscillation power amplitude greater than the average oscillation power amplitude.

[0016] Optionally, it also includes: for each oscillation frequency cluster, obtaining the dominant oscillation frequency of the current oscillation frequency cluster using equation (1) or (2):

[0017]

[0018]

[0019] Among them, f main Let P be the dominant oscillation frequency of the current oscillation frequency cluster, k be the plant node number, n be the total number of plant nodes covered by the current oscillation frequency cluster, and P be the total number of plant nodes covered by the current oscillation frequency cluster. k Let f be the oscillation power amplitude at node k of the power plant. k I represents the dominant oscillation frequency of node k in the current oscillation frequency cluster.k U is the amplitude of the oscillating current at node k of the power plant. k U' is the voltage at node k of the power plant, and U' is the preset converted voltage.

[0020] Optionally, within the oscillation range of each oscillation frequency cluster, the oscillation propagation path and oscillation source are obtained based on the oscillation power amplitude of each electrical branch of each plant node, including:

[0021] Within the oscillation range of the current oscillation frequency cluster, obtain the oscillation power amplitude of each electrical branch of each plant node; traverse each electrical branch of each plant node, when the oscillation power amplitude of the current electrical branch is positive, the oscillation propagation path is to flow into the current plant node through the current electrical branch; when the oscillation power amplitude of the current electrical branch is negative, the oscillation propagation path is to flow out of the current plant node through the current electrical branch.

[0022] Within the oscillation range of the current oscillation frequency cluster, a plant node is randomly selected as the initial plant node. According to the oscillation propagation path of the current oscillation frequency cluster, the source is traced to the next higher-level plant node one by one until the current plant node has no higher-level plant node. Then, the current plant node is taken as the oscillation source of the current oscillation frequency cluster. The higher-level plant node is the plant node from which the oscillation flows to the current plant node.

[0023] By traversing each oscillation frequency cluster, the oscillation propagation path and oscillation source of each oscillation frequency cluster can be obtained.

[0024] Optionally, it also includes: displaying the oscillation range, oscillation propagation path, and oscillation source of several oscillation frequency clusters in different colors, with each oscillation frequency cluster corresponding to a different color.

[0025] In a second aspect, the present invention provides a wide-area monitoring system for multiple oscillation sources in a power grid, comprising:

[0026] The oscillation monitoring module is used to acquire the oscillation frequency characteristics of nodes in various plants and stations over a wide area.

[0027] The oscillation frequency analysis module is used to determine the dominant oscillation frequency of each plant node based on the oscillation frequency characteristics of each plant node.

[0028] The clustering module is used to cluster the dominant oscillation frequencies of each plant node to obtain several oscillation frequency clusters;

[0029] The oscillation source tracing module is used to obtain the plant nodes covered by each oscillation frequency cluster, obtain the oscillation range of each oscillation frequency cluster, and within the oscillation range of each oscillation frequency cluster, obtain the oscillation propagation path and oscillation source of each oscillation frequency cluster based on the oscillation power amplitude of each electrical branch of each plant node.

[0030] Optionally, the oscillation frequency analysis module is specifically used for:

[0031] Based on the oscillation frequency characteristics of each plant node, the oscillation voltage amplitude or oscillation power amplitude of each plant node at each oscillation frequency is obtained.

[0032] For each plant node, the dominant oscillation frequency is selected as either the oscillation frequency with an oscillation voltage amplitude greater than the average oscillation voltage amplitude, or the oscillation frequency with an oscillation power amplitude greater than the average oscillation power amplitude.

[0033] Optionally, it also includes a dominant oscillation frequency calculation module, which is used to: for each oscillation frequency cluster, obtain the dominant oscillation frequency of the current oscillation frequency cluster through equation (1) or (2):

[0034]

[0035]

[0036] Among them, f main Let P be the dominant oscillation frequency of the current oscillation frequency cluster, k be the plant node number, n be the total number of plant nodes covered by the current oscillation frequency cluster, and P be the total number of plant nodes covered by the current oscillation frequency cluster. k Let f be the oscillation power amplitude at node k of the power plant. k I represents the dominant oscillation frequency of node k in the current oscillation frequency cluster. k U is the amplitude of the oscillating current at node k of the power plant. k U' is the voltage at node k of the power plant, and U' is the preset converted voltage.

[0037] Optionally, the traceability module is specifically used for:

[0038] Obtain the plant nodes covered by each oscillation frequency cluster, and obtain the oscillation range of each oscillation frequency cluster;

[0039] Within the oscillation range of the current oscillation frequency cluster, obtain the oscillation power amplitude of each electrical branch of each plant node; traverse each electrical branch of each plant node, when the oscillation power amplitude of the current electrical branch is positive, the oscillation propagation path is to flow into the current plant node through the current electrical branch; when the oscillation power amplitude of the current electrical branch is negative, the oscillation propagation path is to flow out of the current plant node through the current electrical branch.

[0040] Within the oscillation range of the current oscillation frequency cluster, a plant node is randomly selected as the initial plant node. According to the oscillation propagation path of the current oscillation frequency cluster, the source is traced to the next higher-level plant node one by one until the current plant node has no higher-level plant node. Then, the current plant node is taken as the oscillation source of the current oscillation frequency cluster. The higher-level plant node is the plant node from which the oscillation flows to the current plant node.

[0041] By traversing each oscillation frequency cluster, the oscillation propagation path and oscillation source of each oscillation frequency cluster can be obtained.

[0042] In a third aspect, the present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above-described wide-area monitoring method for multiple oscillation sources of power grid broadband oscillation.

[0043] In a fourth aspect, the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the above-described wide-area monitoring method for multiple oscillation sources in a power grid broadband oscillation.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] This invention provides a wide-area monitoring method for multiple sources of broadband oscillations in power grids. It acquires the oscillation frequency characteristics of each substation node within a wide area, then determines the dominant oscillation frequency of each substation node based on these characteristics. The dominant oscillation frequencies of each substation node are then clustered to obtain several oscillation frequency clusters. Finally, the substation nodes covered by each oscillation frequency cluster are obtained, along with the oscillation range of each cluster. Within the oscillation range of each frequency cluster, the oscillation propagation path and oscillation source of each frequency cluster are determined based on the oscillation power amplitude of each electrical branch of each substation node. This method enables wide-area monitoring of multiple sources of broadband oscillations occurring simultaneously in the power grid, accurately determining the propagation paths of different oscillation sources, providing support for oscillation source tracing, offering a new technical means for power grid operation monitoring, and maintaining power grid operation safety. Attached Figure Description

[0046] Figure 1 This is a flowchart of a wide-area monitoring method for multiple oscillation sources in a power grid broadband oscillation according to an embodiment of the present invention.

[0047] Figure 2 This is a schematic diagram of a wide-area monitoring architecture for multiple oscillation sources in a power grid broadband oscillation according to an embodiment of the present invention.

[0048] Figure 3 This is a schematic diagram of the cluster analysis of the dominant oscillation frequencies of each plant node in an embodiment of the present invention.

[0049] Figure 4 This is a schematic diagram of oscillation propagation from multiple oscillation sources according to an embodiment of the present invention.

[0050] Figure 5 This is a schematic diagram illustrating the oscillation source tracing principle of an embodiment of the present invention.

[0051] Figure 6This is a block diagram of a wide-area monitoring system for broadband oscillations and multiple oscillation sources in power grids, according to an embodiment of the present invention. Detailed Implementation

[0052] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0053] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0054] The present invention will now be described in further detail with reference to the accompanying drawings:

[0055] See Figure 1 In one embodiment of the present invention, a wide-area monitoring method for multiple sources of broadband oscillations in a power grid is provided. This method can accurately identify multiple oscillation sources over a wide area, effectively supporting dispatching and operation monitoring services and ensuring the safety of power grid operation. Specifically, the wide-area monitoring method for multiple sources of broadband oscillations in a power grid includes the following steps:

[0056] S1: Obtain the oscillation frequency characteristics of each plant node within a wide area.

[0057] S2: Determine the dominant oscillation frequency of each plant node based on the oscillation frequency characteristic of each plant node.

[0058] S3: Cluster the dominant oscillation frequencies of each plant node to obtain several oscillation frequency clusters.

[0059] S4: Obtain the plant nodes covered by each oscillation frequency cluster, obtain the oscillation range of each oscillation frequency cluster, and within the oscillation range of each oscillation frequency cluster, obtain the oscillation propagation path and oscillation source of each oscillation frequency cluster based on the oscillation power amplitude of each electrical branch of each plant node.

[0060] In summary, the wide-area monitoring method for multiple sources of broadband oscillations in power grids of this invention acquires the oscillation frequency characteristics of each substation node within a wide area, then determines the dominant oscillation frequency of each substation node based on these characteristics; clusters the dominant oscillation frequencies of each substation node to obtain several oscillation frequency clusters; finally, it obtains the substation nodes covered by each oscillation frequency cluster, determines the oscillation range of each oscillation frequency cluster, and within the oscillation range of each oscillation frequency cluster, obtains the oscillation propagation path and oscillation source of each oscillation frequency cluster based on the oscillation power amplitude of each electrical branch of each substation node. This method enables wide-area monitoring when multiple sources of broadband oscillations occur in parallel in the power grid, accurately determines the propagation path of each different oscillation source, provides support for oscillation source tracing, offers a new technical means for power grid operation monitoring, and maintains the safety of power grid operation.

[0061] In one possible implementation, the oscillation frequency characteristics of each plant node within a wide area are transmitted in real time from each plant node to the scheduling master station.

[0062] The acquisition of oscillation frequency characteristics of each plant node within a wide area includes: oscillation frequency, oscillation amplitude, and oscillation phase of each oscillation frequency; wherein, oscillation amplitude includes oscillation power amplitude, oscillation voltage amplitude, and oscillation current amplitude; and oscillation phase includes oscillation voltage phase and oscillation current phase.

[0063] See Figure 2 Within the dispatch range, once an oscillation event occurs, the oscillation monitoring devices at all power plants and substations, such as broadband measurement devices, will monitor all oscillation characteristic quantities in real time. Most of these oscillation characteristic quantities fall within the interharmonic range. Specific oscillation characteristic quantities include the voltage, current, and oscillation power of each oscillation signal (interharmonic). The oscillation voltage and oscillation current are the voltage and current corresponding to the oscillation frequency signal. For example, for a 23Hz oscillation, the oscillation voltage is the measured voltage corresponding to the 23Hz frequency, and the oscillation current is the measured current corresponding to the 23Hz frequency. The oscillation power is specific to the oscillation frequency, not the total oscillation power. For example, the oscillation power of a 23Hz oscillation signal is the product of the oscillation voltage and oscillation current corresponding to that frequency.

[0064] If one or more oscillation signals occur simultaneously at a substation node, the broadband measurement and processing unit deployed at the substation will summarize the oscillation information from the broadband measurement devices and promptly transmit the current, voltage amplitude, and phase information of one or more oscillation signals to the dispatch master station, along with oscillation alarm information. Upon receiving the oscillation alarm information from each substation node, the dispatch master station will identify these substation nodes and display the frequency, amplitude, and phase information of the oscillation current and voltage of each substation node.

[0065] In one possible implementation, determining the dominant oscillation frequency of each plant node based on its oscillation frequency characteristic includes: obtaining the oscillation voltage amplitude or oscillation power amplitude of each oscillation frequency of each plant node based on its oscillation frequency characteristic; for each plant node, selecting an oscillation frequency with an oscillation voltage amplitude greater than the average oscillation voltage amplitude, or selecting an oscillation frequency with an oscillation power amplitude greater than the average oscillation power amplitude as the dominant oscillation frequency.

[0066] Specifically, when a power plant node displays an oscillation alarm, the dispatch master station identifies the relevant node and displays its dominant oscillation frequency. The dominant oscillation frequency is chosen because some power plant nodes may involve multiple oscillation frequencies. This can occur due to two main reasons: firstly, the oscillation within the power plant node itself may exhibit multiple frequencies; secondly, multiple oscillation sources at the power grid level may pass through the same power plant node during propagation, leading to the detection of multiple oscillation frequencies at the power plant. Since the dispatch master station involves wide-area monitoring, it cannot comprehensively display all oscillation frequencies of each power plant node at a wide area. Therefore, it is necessary to analyze the dominant frequency and display the most prevalent oscillation.

[0067] The key to determining the dominant frequency is to assess the power or oscillation current of the oscillation signal transmitted from the same substation node. Generally, the frequency signal with the larger oscillation current or power is considered the dominant oscillation signal. The oscillation frequency signals transmitted from each substation node are sorted at the master station level according to the magnitude of the oscillation current or power. Then, the average of all oscillation signals is taken according to their current or power. The amplitude of each sorted oscillation signal is compared with the average; the frequency greater than the average is identified as the dominant oscillation frequency.

[0068] In one possible implementation, when clustering the dominant oscillation frequencies of each plant node to obtain several oscillation frequency clusters, the number of oscillation frequency clusters can be used as the number of oscillation sources.

[0069] Specifically, the oscillation frequency of the same oscillation source can vary slightly over a wide area due to differences in power grid topology parameters. For example, the topology parameters of the power grid differ depending on whether the oscillation propagates over 20km or 50km, leading to variations in the oscillation frequency. Furthermore, measurement errors within the measuring device itself can also cause deviations in the oscillation monitoring results.

[0070] Therefore, the oscillation frequencies exhibited by various plant nodes within a wide area are unlikely to be exactly the same, necessitating a degree of fuzzy judgment. Furthermore, when multiple different oscillation sources are present, multiple oscillation frequencies may also occur, leading to a significant number of different values ​​for oscillation frequencies across the wide area. For example, a plant node might detect oscillations of 23.1Hz, 76.9Hz, 125Hz, and 164Hz, while neighboring plant nodes might detect 23.3Hz, 76.7Hz, 124.8Hz, and 164.3Hz. Based solely on the amplitude of the oscillations, these two plant nodes might have eight different oscillation frequencies, but in reality, some oscillation signals originate from the same source. This example only compares two plant nodes; however, with a large number of plant nodes across a wide area, the number of detected oscillation frequencies would be even greater. Therefore, in a wide area, it is necessary to perform cluster analysis on these oscillation frequency signals to identify the specific number of oscillation sources.

[0071] See Figure 3 Cluster analysis can specifically employ the K-means algorithm to classify the dominant oscillation frequency signals of all plant nodes, identifying one or more distinct oscillation frequency clusters. Each cluster can then be considered a different oscillation source. However, since subsynchronous / supersynchronous oscillations often occur in pairs, the same oscillation source may generate subsynchronous / supersynchronous oscillation signals, for example, simultaneously generating 27Hz or 73Hz. In this case, the two frequencies belong to different oscillation frequency clusters. Using this method, they are considered two different oscillation sources. However, this does not affect the final source tracing, because the oscillation source at this stage is only a preliminary determination during the transition process. When performing final oscillation source tracing analysis, it will be found that both 27Hz and 73Hz originate from the same source. Therefore, the initial oscillation source determination will not affect the final analysis.

[0072] In one possible implementation, obtaining the oscillation propagation path and oscillation source of each oscillation frequency cluster based on the oscillation power amplitude of each electrical branch of each plant node within the oscillation range of each oscillation frequency cluster includes: obtaining the oscillation power amplitude of each electrical branch of each plant node within the oscillation range of the current oscillation frequency cluster; traversing each electrical branch of each plant node, where if the oscillation power amplitude of the current electrical branch is positive, the oscillation propagation path is through the current electrical branch into the current plant node; if the oscillation power amplitude of the current electrical branch is negative, ... The oscillation propagation path is through the current electrical branch and out of the current plant node. Within the oscillation range of the current oscillation frequency cluster, a plant node is randomly selected as the initial plant node. According to the oscillation propagation path of the current oscillation frequency cluster, the source is traced to the next higher-level plant node one by one until the current plant node has no higher-level plant node. The current plant node is then taken as the oscillation source of the current oscillation frequency cluster. The next higher-level plant node is the plant node from which the oscillation flows to the current plant node. By traversing each oscillation frequency cluster, the oscillation propagation path and oscillation source of each oscillation frequency cluster are obtained.

[0073] Optionally, the oscillation range, oscillation propagation path, and oscillation source of several oscillation frequency clusters can be displayed differently using different colors, with each oscillation frequency cluster corresponding to a different color.

[0074] For details, see Figure 4 The system identifies the plant nodes covered by each oscillation frequency cluster at a wide-area level, dynamically associates these nodes, and displays the oscillation range. Plant nodes involved in multiple oscillation frequency clusters are displayed differently using different colors to show the oscillation range. Then, based on each different oscillation range, the oscillation propagation path and oscillation source are determined according to the paths of oscillation power flowing into and out of each plant node. If the oscillation power amplitude of the electrical branch is positive, it indicates that the oscillation is flowing into the node; if the oscillation power amplitude of the electrical branch is negative, it indicates that the oscillation is flowing out of the node. The direction of oscillation propagation is identified based on the direction of oscillation inflow and outflow, and the final oscillation propagation path is determined accordingly.

[0075] Regarding the oscillation source, see Figure 5 Then, arbitrarily select a plant node within the oscillation range and trace back to its upstream plant node according to the oscillation propagation path. The upstream plant node is the plant node from which the oscillation power flows. Continue tracing back in this way until there are no more upstream plant nodes. The last plant node traced back is the oscillation source.

[0076] When tracing back to the next higher-level plant node, if the previous level involves multiple electrical branches, these branches are traced in parallel. Each branch traces back to its respective next higher-level plant node until no further higher-level plant nodes are found. At this point, all the plant nodes found after parallel tracing of each electrical branch are considered oscillation sources. The propagation path of the oscillation is identified according to the inflow and outflow paths of the oscillation power, thus forming an oscillation propagation path diagram.

[0077] In one possible implementation, to facilitate the analysis of each oscillation frequency cluster or oscillation source, the wide-area monitoring method for multiple oscillation sources of the power grid broadband oscillation further includes: for each oscillation frequency cluster, obtaining the dominant oscillation frequency of the current oscillation frequency cluster through equation (1) or (2):

[0078]

[0079]

[0080] Among them, f main Let P be the dominant oscillation frequency of the current oscillation frequency cluster, k be the plant node number, n be the total number of plant nodes covered by the current oscillation frequency cluster, and P be the total number of plant nodes covered by the current oscillation frequency cluster. k Let f be the oscillation power amplitude at node k of the power plant. k I represents the dominant oscillation frequency of node k in the current oscillation frequency cluster. k U is the amplitude of the oscillating current at node k of the power plant. k U' is the voltage at node k of the power plant, and U' is the preset converted voltage.

[0081] Among them, the dominant oscillation frequency of plant node k in the current oscillation frequency cluster specifically refers to the dominant oscillation frequency that is clustered into the current oscillation frequency cluster among all the dominant oscillation frequencies of plant node k.

[0082] Specifically, if a single power plant node exhibits multiple dominant oscillation frequencies, then there will be multiple distinct frequency clusters at the master station's wide-area perspective. Each oscillation frequency cluster may contain the same power plant node. This ensures that even if a power plant node has multiple dominant oscillation frequencies, all frequencies will be covered. For example, if a power plant node has two dominant oscillation frequencies, 12Hz and 68Hz, then as the oscillations propagate, the master station level may have two different oscillation frequency clusters: 12Hz and 68Hz. The 12Hz frequency cluster will cover the power plant node, and the 68Hz frequency cluster will also cover it. The final propagation paths will be displayed according to the differences in oscillation frequencies.

[0083] Specifically, for the oscillation frequency clusters formed after cluster analysis, it is necessary to obtain the dominant oscillation frequency of each oscillation frequency cluster to facilitate the identification of this oscillation frequency at a wide-area level.

[0084] The oscillation frequencies of various different oscillation frequency clusters are compared and analyzed using either oscillation current or oscillation power, focusing on the dominant oscillation frequency f. main Specifically, the dominant oscillation frequency can be obtained through analysis using either oscillation current or oscillation power. The oscillation power method involves multiplying the oscillation frequency amplitude transmitted by each plant node by the oscillation power amplitude, summing the calculated results for all plant nodes, and then dividing by the sum of the oscillation power amplitudes to obtain the dominant oscillation frequency. The oscillation current method involves directly multiplying each oscillation frequency in the oscillation frequency cluster by the corresponding interharmonic current amplitude, summing the calculated results for all plant nodes, and then dividing by the sum of the oscillation current amplitudes to obtain the dominant oscillation frequency.

[0085] When applying the oscillating current method, it can be used directly for substation nodes of the same voltage level. However, for substations of different voltage levels, the oscillating current under different voltage levels needs to be uniformly converted to the same voltage level. This involves multiplying the amplitude of the oscillating current at the current voltage level by the voltage level itself, and then dividing by the voltage level being converted. For example, for 220kV and 110kV substation nodes, the conversion can be done using either the high-voltage or low-voltage conversion method. If converting to a high voltage level, the oscillating current of the 110kV substation is multiplied by 110 and then divided by 220; if converting from a high voltage level to a low voltage level, the oscillating current of the 220kV substation is multiplied by 220 and then divided by 110. Generally speaking, when converting from a high voltage level to a low voltage level, the current will increase, and the increase is exactly the ratio of high voltage to low voltage, and vice versa.

[0086] The following are embodiments of the apparatus of the present invention, which can be used to execute embodiments of the method of the present invention. For details not disclosed in the apparatus embodiments, please refer to the embodiments of the method of the present invention.

[0087] See Figure 6 In another embodiment of the present invention, a wide-area monitoring system for multiple sources of broadband oscillation in a power grid is provided, which can be used to implement the above-mentioned wide-area monitoring method for multiple sources of broadband oscillation in a power grid. Specifically, the wide-area monitoring system for multiple sources of broadband oscillation in a power grid includes an oscillation monitoring module, an oscillation frequency analysis module, a clustering module, and an oscillation source tracing module.

[0088] The oscillation monitoring module is used to acquire the oscillation frequency characteristics of each plant node within a wide area; the oscillation frequency analysis module is used to determine the dominant oscillation frequency of each plant node based on the oscillation frequency characteristics of each plant node; the clustering module is used to cluster the dominant oscillation frequencies of each plant node to obtain several oscillation frequency clusters; and the oscillation source tracing module is used to acquire the plant nodes covered by each oscillation frequency cluster, obtain the oscillation range of each oscillation frequency cluster, and within the oscillation range of each oscillation frequency cluster, obtain the oscillation propagation path and oscillation source of each oscillation frequency cluster based on the oscillation power amplitude of each electrical branch of each plant node.

[0089] In one possible implementation, the oscillation frequency characteristics of each plant node within a wide area are transmitted in real time from each plant node to the dispatch master station; the acquisition of the oscillation frequency characteristics of each plant node within a wide area includes: oscillation frequency and oscillation amplitude and oscillation phase of each oscillation frequency; wherein, the oscillation amplitude includes oscillation power amplitude, oscillation voltage amplitude and oscillation current amplitude; the oscillation phase includes oscillation voltage phase and oscillation current phase.

[0090] In one possible implementation, the oscillation frequency analysis module is specifically used to: obtain the oscillation voltage amplitude or oscillation power amplitude of each oscillation frequency of each plant node based on the oscillation frequency characteristic quantity of each plant node; for each plant node, select the oscillation frequency with an oscillation voltage amplitude greater than the average oscillation voltage amplitude, or select the oscillation frequency with an oscillation power amplitude greater than the average oscillation power amplitude as the dominant oscillation frequency.

[0091] In one possible implementation, the tracing module is specifically used for: obtaining the oscillation power amplitude of each electrical branch of each plant node within the oscillation range of the current oscillation frequency cluster; traversing each electrical branch of each plant node, where if the oscillation power amplitude of the current electrical branch is positive, the oscillation propagation path is through the current electrical branch into the current plant node; if the oscillation power amplitude of the current electrical branch is negative, the oscillation propagation path is through the current electrical branch out of the current plant node; within the oscillation range of the current oscillation frequency cluster, randomly selecting a plant node as the initial plant node, and tracing the source to the next higher-level plant node one by one according to the oscillation propagation path of the current oscillation frequency cluster, until the current plant node has no higher-level plant node, then taking the current plant node as the oscillation source of the current oscillation frequency cluster; wherein, the next higher-level plant node is the plant node from which the oscillation flows to the current plant node; and traversing each oscillation frequency cluster to obtain the oscillation propagation path and oscillation source of each oscillation frequency cluster.

[0092] In one possible implementation, a display module is also included, which is used to differentiate the oscillation range, oscillation propagation path and oscillation source of several oscillation frequency clusters by using different colors, with each oscillation frequency cluster corresponding to a different color.

[0093] In one possible implementation, it further includes: a dominant oscillation frequency calculation module, which is used to: for each oscillation frequency cluster, obtain the dominant oscillation frequency of the current oscillation frequency cluster using equation (1) or (2):

[0094]

[0095]

[0096] Among them, f main Let P be the dominant oscillation frequency of the current oscillation frequency cluster, k be the plant node number, n be the total number of plant nodes covered by the current oscillation frequency cluster, and P be the total number of plant nodes covered by the current oscillation frequency cluster. k Let f be the oscillation power amplitude at node k of the power plant. k I represents the dominant oscillation frequency of node k in the current oscillation frequency cluster. k U is the amplitude of the oscillating current at node k of the power plant. k U' is the voltage at node k of the power plant, and U' is the preset converted voltage.

[0097] All relevant content of each step involved in the aforementioned embodiments of the wide-area monitoring method for wide-frequency oscillations of power grids with multiple oscillation sources can be referenced from the functional description of the corresponding functional module of the wide-area monitoring system for wide-frequency oscillations of power grids with multiple oscillation sources in the embodiments of the present invention, and will not be repeated here.

[0098] The module division in this embodiment of the invention is illustrative and represents only one logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional modules in the various embodiments of the invention can be integrated into a single processor, exist as separate physical entities, or be integrated into a single module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0099] In another embodiment of the present invention, a computer device is provided, comprising a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions from the computer storage medium to achieve a corresponding method flow or corresponding function. The processor described in this embodiment of the present invention can be used for the operation of a wide-area monitoring method for multi-source oscillations in power grids.

[0100] In another embodiment of the present invention, a storage medium is provided, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device used to store programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and extended storage media supported by the computer device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, the storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be high-speed RAM or non-volatile memory, such as at least one disk storage device. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the corresponding steps of the wide-area monitoring method for multiple oscillation sources of power grid broadband oscillations in the above embodiments.

[0101] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied 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.

[0102] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. 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, generate instructions 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.

[0103] 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.

[0104] 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.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A wide-area monitoring method for multiple oscillation sources in a power grid with wide-frequency oscillation, characterized in that, include: Obtain the oscillation frequency characteristics of each plant node within a wide area; Based on the oscillation frequency characteristics of each plant node, the dominant oscillation frequency of each plant node is determined. Clustering the dominant oscillation frequencies of each plant node yields several oscillation frequency clusters; Obtain the plant nodes covered by each oscillation frequency cluster, obtain the oscillation range of each oscillation frequency cluster, and within the oscillation range of each oscillation frequency cluster, obtain the oscillation propagation path and oscillation source of each oscillation frequency cluster based on the oscillation power amplitude of each electrical branch of each plant node. Within the oscillation range of each oscillation frequency cluster, the oscillation propagation path and oscillation source of each oscillation frequency cluster are obtained based on the oscillation power amplitude of each electrical branch of each plant node, including: Within the oscillation range of the current oscillation frequency cluster, obtain the oscillation power amplitude of each electrical branch of each plant node; traverse each electrical branch of each plant node, when the oscillation power amplitude of the current electrical branch is positive, the oscillation propagation path is to flow into the current plant node through the current electrical branch; when the oscillation power amplitude of the current electrical branch is negative, the oscillation propagation path is to flow out of the current plant node through the current electrical branch. Within the oscillation range of the current oscillation frequency cluster, a plant node is randomly selected as the initial plant node. According to the oscillation propagation path of the current oscillation frequency cluster, the source is traced to the next higher-level plant node one by one until the current plant node has no higher-level plant node. Then, the current plant node is taken as the oscillation source of the current oscillation frequency cluster. The higher-level plant node is the plant node from which the oscillation flows to the current plant node. By traversing each oscillation frequency cluster, the oscillation propagation path and oscillation source of each oscillation frequency cluster can be obtained.

2. The wide-area monitoring method for multiple oscillation sources in a power grid according to claim 1, characterized in that, The oscillation frequency characteristics of each plant node within a wide area are transmitted to the dispatch master station in real time by each plant node; The acquisition of oscillation frequency characteristics of each plant node within a wide area includes: oscillation frequency, oscillation amplitude, and oscillation phase of each oscillation frequency; wherein, oscillation amplitude includes oscillation power amplitude, oscillation voltage amplitude, and oscillation current amplitude; and oscillation phase includes oscillation voltage phase and oscillation current phase.

3. The wide-area monitoring method for multiple oscillation sources in a power grid according to claim 1, characterized in that, The process of determining the dominant oscillation frequency of each plant node based on its oscillation frequency characteristics includes: Based on the oscillation frequency characteristics of each plant node, the oscillation voltage amplitude or oscillation power amplitude of each plant node at each oscillation frequency is obtained. For each plant node, the dominant oscillation frequency is selected as either the oscillation frequency with an oscillation voltage amplitude greater than the average oscillation voltage amplitude, or the oscillation frequency with an oscillation power amplitude greater than the average oscillation power amplitude.

4. The wide-area monitoring method for multiple oscillation sources in a power grid with wide frequency band oscillations according to claim 1, characterized in that, Also includes: For each oscillation frequency cluster, the dominant oscillation frequency of the current oscillation frequency cluster can be obtained through equation (1) or (2): （1） （2） in, This is the dominant oscillation frequency of the current oscillation frequency cluster. k Number the plant / station nodes. n This represents the total number of plant nodes covered by the current oscillation frequency cluster. For plant nodes k The amplitude of the oscillation power, For the current oscillation frequency cluster of power plant nodes k The dominant oscillation frequency, For plant nodes k The amplitude of the oscillating current, For plant nodes k voltage, This is the preset conversion voltage.

5. The wide-area monitoring method for multiple oscillation sources in a power grid according to claim 1, characterized in that, Also includes: By assigning a color to each oscillation frequency cluster, the oscillation range, oscillation propagation path, and oscillation source of several oscillation frequency clusters are displayed differently using different colors.

6. A wide-area monitoring system for multiple oscillation sources in a power grid with wide frequency bands, characterized in that, include: The oscillation monitoring module is used to acquire the oscillation frequency characteristics of nodes in various plants and stations over a wide area. The oscillation frequency analysis module is used to determine the dominant oscillation frequency of each plant node based on the oscillation frequency characteristics of each plant node. The clustering module is used to cluster the dominant oscillation frequencies of each plant node to obtain several oscillation frequency clusters; The oscillation source tracing module is used to obtain the plant nodes covered by each oscillation frequency cluster, obtain the oscillation range of each oscillation frequency cluster, and within the oscillation range of each oscillation frequency cluster, obtain the oscillation propagation path and oscillation source of each oscillation frequency cluster based on the oscillation power amplitude of each electrical branch of each plant node. The traceability module is specifically used for: Obtain the plant nodes covered by each oscillation frequency cluster, and obtain the oscillation range of each oscillation frequency cluster; Within the oscillation range of the current oscillation frequency cluster, obtain the oscillation power amplitude of each electrical branch of each plant node; traverse each electrical branch of each plant node, when the oscillation power amplitude of the current electrical branch is positive, the oscillation propagation path is to flow into the current plant node through the current electrical branch; when the oscillation power amplitude of the current electrical branch is negative, the oscillation propagation path is to flow out of the current plant node through the current electrical branch. Within the oscillation range of the current oscillation frequency cluster, a plant node is randomly selected as the initial plant node. According to the oscillation propagation path of the current oscillation frequency cluster, the source is traced to the next higher-level plant node one by one until the current plant node has no higher-level plant node. Then, the current plant node is taken as the oscillation source of the current oscillation frequency cluster. The higher-level plant node is the plant node from which the oscillation flows to the current plant node. By traversing each oscillation frequency cluster, the oscillation propagation path and oscillation source of each oscillation frequency cluster can be obtained.

7. The wide-area monitoring system for multiple oscillation sources in a power grid according to claim 6, characterized in that, The oscillation frequency analysis module is specifically used for: Based on the oscillation frequency characteristics of each plant node, the oscillation voltage amplitude or oscillation power amplitude of each plant node at each oscillation frequency is obtained. For each plant node, the dominant oscillation frequency is selected as either the oscillation frequency with an oscillation voltage amplitude greater than the average oscillation voltage amplitude, or the oscillation frequency with an oscillation power amplitude greater than the average oscillation power amplitude.

8. The wide-area monitoring system for multiple oscillation sources in a power grid according to claim 6, characterized in that, It also includes a dominant oscillation frequency calculation module, which is used to: for each oscillation frequency cluster, obtain the dominant oscillation frequency of the current oscillation frequency cluster by means of equation (1) or (2): （1） （2） in, This is the dominant oscillation frequency of the current oscillation frequency cluster. k Number the plant / station nodes. n This represents the total number of plant nodes covered by the current oscillation frequency cluster. For plant nodes k The amplitude of the oscillation power, For the current oscillation frequency cluster of power plant nodes k The dominant oscillation frequency, For plant nodes k The amplitude of the oscillating current, For plant nodes k voltage, This is the preset conversion voltage.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the wide-area monitoring method for multiple oscillation sources of power grid broadband oscillation as described in any one of claims 1 to 5.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the wide-area monitoring method for multiple oscillation sources of power grid broadband oscillation as described in any one of claims 1 to 5.

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