Oscillation control methods, systems and electronic equipment for grid-connected power plants

Abstract

This application discloses an oscillation control method, system, and electronic equipment for grid-connected power plants, belonging to the field of new energy grid-connected control technology. It includes determining the control levels corresponding to multiple protection elements within the grid-connected power plant, wherein different control levels have a topological order relationship; in response to the detection of an oscillating element among the protection elements, hierarchical oscillation elimination control is performed on each oscillating element according to the topological order relationship of the control levels corresponding to the oscillating element. This application can improve the coordination and precision of the oscillation elimination process, achieving a balance between the safe and stable operation of the grid-connected power plant and the economic efficiency of power generation and consumption.

Description

Technical Field

[0001] This application relates to the field of new energy grid-connected control technology, specifically to an oscillation control method, system, and electronic equipment for grid-connected power plants. Background Technology

[0002] With the increasing scale of power electronic equipment such as new energy sources and energy storage being connected to the grid, grid-connected power plants are more susceptible to broadband oscillations caused by factors such as changes in control parameters, network impedance, and operating conditions. To reduce the impact of oscillations on the grid-connected operation of power plants, oscillation monitoring and control functions are typically configured for key equipment or lines within the power plant during engineering projects. Once an oscillation exceeds the limit, corresponding control measures are triggered to suppress its continued development.

[0003] However, grid-connected power stations have a wide variety and large number of internal equipment, and complex electrical connections. Oscillations can affect each other between different equipment or lines. When oscillation anomalies occur at multiple locations close to each other simultaneously, the control precision of the relevant broadband oscillation control schemes is insufficient, which can easily lead to timing overlap and control conflicts, causing over-switching of units and increasing the risk of broadband oscillations in grid-connected power stations, thus resulting in lower safety of grid-connected power stations. Summary of the Invention

[0004] This invention provides an oscillation control method, system, and electronic equipment for grid-connected power plants, aiming to solve the problem that oscillation elimination control in existing oscillation control schemes for grid-connected power plants can easily lead to low safety of the power plants.

[0005] Firstly, an oscillation control method for grid-connected power plants is provided, comprising the following steps: Determine the control levels corresponding to multiple defense components within a grid-connected power station, wherein there is a topological order relationship between different control levels; In response to the detection of an oscillating element among the defense elements, hierarchical oscillation elimination control is performed on each of the oscillating elements according to the topological order of the control levels corresponding to the oscillating elements.

[0006] In some embodiments, the response to detecting the presence of an oscillating element in the defense element includes: Collect the target electrical quantities of the defense components and calculate the oscillation characteristic quantities corresponding to the target electrical quantities; The oscillation state of the defense element is determined based on the oscillation characteristic quantity and the preset oscillation action threshold value. Based on the oscillation state of each of the aforementioned defensive elements, the oscillating element among the defensive elements that is oscillating is determined.

[0007] In some embodiments, oscillation cancellation control is performed on each of the oscillation elements according to the topological order of the control levels corresponding to the oscillation elements, including: In the case where there are oscillating elements in the defense elements within at least two control levels, based on the topological order relationship between the at least two control levels, hierarchical oscillation elimination control is performed on the oscillating elements in different control levels, and round-robin oscillation elimination control is performed on multiple oscillating elements within the same control level.

[0008] In some embodiments, the hierarchical oscillation elimination control of oscillating elements within different control levels includes: According to the control level from low to high, the oscillation elements in each control level are subjected to hierarchical oscillation elimination control; After the current round of hierarchical oscillation elimination control is completed, if a new oscillating element or a remaining oscillating element is detected, the hierarchical oscillation elimination control steps are executed cyclically.

[0009] In some embodiments, the step of performing oscillation elimination control on multiple oscillating elements within the same control level includes: In the case of multiple oscillating elements within the same control level, an intra-level control sequence for the multiple oscillating elements in the current control level is established according to the oscillation action time and / or the priority of the oscillation control factor. The oscillation control factor includes at least one of oscillation amplitude, element characteristics, oscillation duration, power frequency power, and electrical position. The control rounds are determined according to the layer control sequence, and the oscillation element is subjected to round-by-round oscillation elimination control in turn.

[0010] In some embodiments, determining the control round according to the intra-layer control sequence includes: In each control round, the target control quantity corresponding to the oscillating element is accumulated according to the control sequence within the layer, with the preset upper limit of the target control quantity in a single round as a constraint, to determine the control object of the current round.

[0011] In some embodiments, the step of performing round-by-round oscillation elimination control on the oscillating element includes: After each control round is executed, wait for a preset inter-round delay, and reacquire the oscillation state of the uncontrolled defensive elements within the control level, or reacquire the oscillation state of all the defensive elements in the subordinate control levels of the current control level. In response to the detection of an oscillating element, the system proceeds to the next control cycle based on the updated oscillation state.

[0012] In some embodiments, each of the defense elements is equipped with an oscillation action flag and an oscillation reset flag; The method further includes: After any control cycle is executed, if all oscillation elements in the current control level generate an oscillation reset flag, or if there is no oscillation action flag in the current control level, the control action of the current control level ends.

[0013] In some embodiments, the control hierarchy includes a power generation layer, a power collection layer, and a grid connection layer with increasing control priority; The step of performing tiered oscillation elimination control on the oscillating elements within each control level, in ascending order of control level, includes: For the power generation layer, oscillation elimination control is performed on the defense elements of the power generation layer in sequence; For the current collector layer, oscillation cancellation control is performed sequentially on the protection elements of the current collector layer; For the grid-connected layer, the defense element in the subordinate control level corresponding to the oscillation state of the grid-connected layer performs oscillation cancellation control.

[0014] In some embodiments, determining the control levels corresponding to multiple protection components within a grid-connected power station includes: Obtain the topology association information of multiple protection components within a grid-connected power station; Based on the topological association information of the defense elements, the multiple defense elements are assigned to different control levels.

[0015] Secondly, an oscillation control system for a grid-connected power station is also provided, the oscillation control system comprising: The control level determination module is used to determine the control level corresponding to multiple defense components in a grid-connected power station, wherein there is a topological order relationship between different control levels; An oscillation detection and control module is used to respond to the detection of an oscillating element in the defense components, and to perform hierarchical oscillation elimination control on each of the oscillating elements according to the topological order of the control levels corresponding to the oscillating elements.

[0016] Thirdly, an electronic device is also provided, including a memory and a processor, wherein a computer program is stored on the memory, and the computer program, when executed by the processor, implements the method as described in any of the preceding claims.

[0017] Fourthly, a computer-readable storage medium is also provided, on which a computer program is stored, the computer program being loaded by a processor to perform the steps of the method as described in any of the preceding claims.

[0018] Beneficial effects: This application establishes a hierarchical control hierarchy based on the electrical location and topological relationships of various protection components within a grid-connected power station. Upon detecting an oscillating component, it executes layered oscillation elimination control in conjunction with its respective control hierarchy. This allows oscillation control to proceed systematically according to the electrical connections within the power station, rather than relying solely on the independent action of a single component. Consequently, when multiple protection components, especially those in different electrical locations, oscillate simultaneously or nearly simultaneously, the coordination and precision of the oscillation elimination process are improved, reducing the risks of over-cutting, under-cutting, and unnecessary equipment shutdown, thereby effectively enhancing the operational safety of grid-connected power stations. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic flowchart of an oscillation control method for grid-connected power plants provided in an exemplary embodiment of this disclosure; Figure 2 This is a flowchart of a hierarchical oscillation control method for grid-connected power plants provided in an exemplary embodiment of this disclosure; Figure 3 This is a timing logic diagram of the generation layer of a grid-connected power station provided in an exemplary embodiment of this disclosure; Figure 4 This is a timing logic diagram of the sorting control of the collector layer of a grid-connected power station provided in an exemplary embodiment of this disclosure; Figure 5 This is a timing logic diagram of the grid connection layer of a grid-connected power station provided in an exemplary embodiment of this disclosure; Figure 6 This is a schematic diagram of the functional modules of the oscillation control system of a grid-connected power station provided in an exemplary embodiment of this disclosure; Figure 7 This is an example embodiment of the oscillation control system architecture of a grid-connected power station provided in this disclosure; Figure 8 This is the main wiring diagram of a grid-connected power station provided in an exemplary embodiment of this disclosure. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0023] "A and / or B" includes the following three combinations: A only, B only, and a combination of A and B.

[0024] The use of "applies to" or "configured to" in this application implies open and inclusive language, which does not exclude the applicability to or configuration to devices performing additional tasks or steps. Additionally, the use of "based on" implies openness and inclusivity, because processes, steps, calculations, or other actions "based on" one or more of the stated conditions or values ​​may in practice be based on additional conditions or values ​​beyond those stated.

[0025] In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use this application. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that this application can be made without using these specific details. In other instances, well-known structures and processes are not described in detail to avoid obscuring the description of this application with unnecessary detail. Therefore, this application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0026] On the one hand, this embodiment provides an oscillation control method for grid-connected power stations. Applicable grid-connected power stations include, but are not limited to, wind farms, photovoltaic power stations, integrated wind-solar-storage power stations, integrated solar-storage power stations, and integrated wind-storage power stations, as well as other new energy aggregation stations containing energy storage power stations. For example... Figure 1 As shown, the method includes the following steps: Step 1000: Determine the control level corresponding to multiple protection components within the grid-connected power station, where there is a topological order relationship between different control levels.

[0027] Specifically, the equipment type, installation location, access interval, and electrical connection relationship with the grid connection point of each protection element within the grid-connected power station can be obtained first. Protection elements may include generation units, transformer substations, collector lines, reactive power compensation equipment, main transformer related intervals, and grid connection outgoing lines. Then, based on the relative position of each protection element in the primary wiring structure of the station, the upstream / downstream relationship or sequential propagation relationship between the protection elements is determined, and protection elements with similar electrical locations and control object attributes are grouped into the same control level. For example, protection elements closer to the generation equipment side can be determined as lower control levels, protection elements located in collector lines or reactive power compensation links can be determined as intermediate control levels, and protection elements closer to the grid connection point or station outlet side can be determined as higher control levels, thus forming multiple control levels with topological sequential relationships.

[0028] Step 2000: In response to the detection of an oscillating element in the armored components, hierarchical oscillation elimination control is performed on each oscillating element according to the topological order of the control levels corresponding to the oscillating elements.

[0029] Specifically, the system continuously collects operating electrical quantities such as voltage, current, and power at corresponding intervals of each protection element, and determines whether each protection element is oscillating based on the collected electrical quantities. If one or more protection elements are detected to meet the oscillation action conditions, they are identified as oscillating elements, and the control level to which each oscillating element belongs is further determined. After identifying the presence of oscillating elements, instead of simply executing control on all oscillating elements simultaneously, the system considers the topological order between the control levels of each oscillating element and performs layered oscillation elimination control on the oscillating elements within different control levels according to a preset hierarchical sequence. For the control level currently requiring processing, the control action of the oscillating elements within that level can be enabled, while the control actions of other levels can be restricted. After the oscillation at the current level is suppressed or the reset condition is met, the system proceeds to the next relevant control level for further processing. This reduces the overlap of oscillation control actions at different electrical locations, lowering the risk of redundant control or over-cutting.

[0030] This embodiment establishes a hierarchical control hierarchy based on the electrical location and topological relationships of each protection element within the grid-connected power station. Upon detecting an oscillating element, it executes layered oscillation elimination control in conjunction with its respective control hierarchy. This allows oscillation control to proceed systematically according to the electrical connections within the power station, rather than relying solely on the independent action of a single element. In this way, when multiple protection elements, especially those in different electrical locations, oscillate simultaneously or nearly simultaneously, the timing overlap, control conflicts, and redundant cut-offs caused by concurrent triggering of control actions at different levels can be reduced. This facilitates prioritizing the handling of oscillating elements closer to the oscillation source or at lower levels, addressing higher-level oscillations only after their oscillations are eliminated. This improves the coordination and precision of the oscillation elimination process, reduces the risks of over-cutting, under-cutting, and unnecessary equipment shutdown, and achieves a balance between the safe and stable operation of the grid-connected power station and the economic efficiency of power generation and consumption.

[0031] In some embodiments, step 2000, in response to detecting the presence of an oscillating element in the protection element, includes: Step 2100: Collect the target electrical quantities of the defense components and calculate the oscillation characteristic quantities corresponding to the target electrical quantities.

[0032] Specifically, target electrical quantities can be collected for monitoring intervals corresponding to each protected component within a grid-connected power station. These target electrical quantities may include three-phase voltage, three-phase current, power, and related operating quantities converted from voltage and current. For example, the control hierarchy of the grid-connected power station can be defined as the generation layer, the collector layer, and the grid connection layer. For protected components in the generation layer, the target electrical quantities can be collected by the source control terminal device on the generation unit side or the transformer substation side. For protected components in the collector layer and the grid connection layer, the target electrical quantities of the collector lines, reactive power compensation equipment, main transformer related intervals, or grid-connected outgoing lines can be collected by the station-side oscillation monitoring device. After collecting the target electrical quantities, the oscillation components can be extracted to obtain oscillation characteristic quantities characterizing the oscillation status of the protected components. These oscillation characteristic quantities may include at least one of power oscillation characteristic quantities, current oscillation characteristic quantities, and voltage oscillation characteristic quantities, and may further include information such as oscillation amplitude, oscillation frequency, and oscillation duration.

[0033] Step 2200: Determine the oscillation state of the defense element based on the oscillation characteristic quantity and the preset oscillation action threshold value.

[0034] Specifically, the oscillation characteristic quantity can be compared with the oscillation action threshold value of the control level to which the corresponding protection element belongs, and the oscillation state of the protection element can be determined by combining criteria such as confirmation delay. Protection elements at different control levels can be configured with independent oscillation action threshold values ​​and confirmation delays to adapt to the differences in equipment capacity, oscillation response, and control objects among the generation layer, collector layer, and grid connection layer.

[0035] For example, if the power, current or voltage-related oscillation characteristic of a certain protection element reaches the corresponding oscillation action threshold value and continues to meet the confirmation conditions, it can be determined that the protection element is in an oscillation action state; after its oscillation characteristic value falls back to the reset condition and remains for a certain period of time, it can be determined that the protection element is in an oscillation elimination or reset state.

[0036] The confirmation condition refers to the condition whereby, after the oscillation characteristic of a protected element reaches or exceeds the oscillation action threshold value corresponding to its control level, the oscillation state of the protected element is determined to be an oscillation action state only if it continuously meets the preset confirmation delay for the action threshold, or continuously meets preset requirements such as the number of oscillation cycles or the duration of oscillation. This generates an oscillation action flag. Therefore, setting confirmation conditions can avoid misjudgments caused by instantaneous disturbances or short-term measurement fluctuations. The reset condition refers to the condition where, after a protected element has been determined to be in an oscillation action state, its oscillation characteristic value decreases below a preset return threshold, or the duration of the oscillation action threshold no longer meets the preset reset confirmation time. In this case, the oscillation of the protected element is determined to have been eliminated or returned to a non-action state, and an oscillation reset flag is generated. Therefore, setting reset conditions can avoid frequent actions and resets when the oscillation characteristic value fluctuates near the threshold.

[0037] Step 2300: Based on the oscillation state of each defense element, determine the oscillating element that is oscillating among the defense elements.

[0038] Specifically, based on whether each defense element is in an oscillating state, the oscillating elements present in the power generation layer, power collection layer, and grid connection layer can be identified, and the control level to which the oscillating element belongs, the time of action, the oscillation amplitude, the oscillation frequency, the corresponding interval, and the executable control object can be recorded. In this way, it can be determined whether the oscillating element exists in a single layer or multiple control layers simultaneously, and further intra-layer round control or inter-layer hierarchical control can be performed accordingly.

[0039] This embodiment collects the target electrical quantities of the protected components and calculates the corresponding oscillation characteristic quantities. Then, by combining this with a preset oscillation action threshold value, it determines the oscillation state of each protected component. This allows it to identify the oscillating component that is actually oscillating from among multiple protected components in a grid-connected power station and clearly define its control level. This reduces misjudgments and omissions caused by instantaneous disturbances or abnormalities in a single measurement quantity, providing reliable object identification results for hierarchical oscillation elimination control and same-level sequential control.

[0040] In some embodiments, step 2000, which involves performing oscillation cancellation control on each oscillation element according to the topological order of the control levels corresponding to the oscillation elements, includes: Step 2400: When there are oscillating elements in the defense elements within at least two control levels, based on the topological order relationship between at least two control levels, perform hierarchical oscillation elimination control on the oscillating elements in different control levels, and perform round-robin oscillation elimination control on multiple oscillating elements within the same control level.

[0041] Specifically, the process can begin by determining whether the current oscillation event involves at least two control levels based on the control level to which each oscillating element belongs. If oscillating elements exist in at least two of the control levels (e.g., generation, collection, grid connection), the inter-level control sequence for this oscillation event is determined based on the topological order from the generation side to the grid connection side among these control levels. Oscillation elimination control is then prioritized for control levels with lower topological positions. For currently open control levels, if multiple oscillating elements exist within that level, an intra-level control sequence can be formed based on factors such as the order of action of each oscillating element, oscillation amplitude, oscillation duration, power frequency, electrical location, or element characteristics. These intra-level control sequences are then used to assign multiple oscillating elements to different control rounds for sequential processing.

[0042] This embodiment performs layered oscillation elimination control on oscillation elements in different control levels based on the topological order between control levels when oscillation elements exist in at least two control levels, and performs round-robin oscillation elimination control on multiple oscillation elements in the same control level. This enables grid-connected power stations to determine the control objects and control timing in an orderly manner according to electrical connection relationships when facing complex operating conditions where multiple elements oscillate simultaneously or nearly simultaneously across levels. This reduces timing overlap and control conflicts caused by concurrent triggering of control actions at different levels.

[0043] In some embodiments, step 2400, which involves performing hierarchical oscillation cancellation control on oscillating elements within different control levels, includes: Step 2410: Perform tiered oscillation elimination control on the oscillation elements within each control level, in ascending order of control level; Step 2420: After the hierarchical oscillation elimination control is completed in this round, if a new oscillation element or a remaining oscillation element is detected, the hierarchical oscillation elimination control steps are executed cyclically.

[0044] Specifically, the control sequence from low to high can be determined based on multiple predetermined control levels and their topological order, such as generation layer, collector layer, and grid connection layer. If oscillating elements are detected in at least two control levels, the lowest control level can be designated as the current control level, and the control output of the oscillating elements within that level can be opened to perform disconnection, blocking, load reduction, or other oscillation elimination controls. For higher control levels that have not yet been addressed, their control outputs can be temporarily closed or their control actions can be blocked to reduce overlap between different control levels. It is easy to understand that the lower the control level, the higher the priority of the corresponding oscillation elimination control.

[0045] After completing one or more rounds of oscillation elimination control at the previous control level, the oscillation state of the protected elements within that level can be reacquired. If the oscillating element within that level meets the oscillation reset condition or there are no longer any oscillation action flags within that level, after a preset inter-level delay, the adjacent higher control level is determined as the new current control level, and oscillation elimination control is performed on the oscillating elements within that adjacent higher control level. If there are no oscillating elements within a certain control level, that control level can be skipped and the process can continue to the next control level. After the highest control level has finished processing, if new oscillating elements or remaining oscillating elements are still detected, the process can restart from the lower control level until the oscillation within the grid-connected power station is eliminated.

[0046] Please see Figure 2 , Figure 2 This is a flowchart of a hierarchical oscillation control method for a grid-connected power station. The control hierarchy of this power station includes a generation layer, a collector layer, and a grid connection layer, with decreasing control priority. Following the order of priority from highest to lowest, oscillation cancellation control is first applied to the protection elements of the generation layer; then, it is applied to the protection elements of the collector layer; finally, it is applied to the protection elements in the subordinate control levels corresponding to the oscillation elements of the grid connection layer. The protection elements of the generation layer can include generation units, converters, or transformer substations formed by multiple converters; the protection elements of the collector layer can include collector lines, static var generators (SVG), and other reactive power compensation equipment, as well as bays related to the collection process. The protection elements of the grid connection layer can include the power station's grid connection outgoing lines or related bays near the grid connection point. Oscillation cancellation control methods include, but are not limited to, disconnection, blocking, or load reduction. If a grid-connected layer protection element is identified as an oscillating element, instead of directly cutting off the grid-connected layer element itself, a target element can be selected from the collector layer or other subordinate layers based on the subordinate control level corresponding to the grid-connected layer oscillation element for cutting off, in order to suppress grid-connected layer oscillation.

[0047] After each control round is executed, a preset inter-round delay can be waited for, and the oscillation status of the relevant defense elements in the current control level can be reacquired. If there are still oscillating elements that have not been eliminated, the next control round will continue to be entered according to the updated control sequence in the layer until the oscillation in the control level is eliminated or the exit condition is met.

[0048] This embodiment employs layered oscillation elimination control of oscillating elements according to a control hierarchy from low to high. This allows control actions at different levels to unfold sequentially along the station topology, prioritizing lower-level oscillating elements and addressing higher-level elements only after their oscillations are eliminated. This reduces cross-level control action overlap, redundant cut-offs, and control conflicts, thus lowering the risk of over-cutting. Simultaneously, the sequential opening of control between levels provides time for oscillation status verification after each level of control. This allows higher-level control decisions to be based on actual oscillation changes after lower-level control, avoiding blindly expanding the control range before lower-level oscillations are eliminated. This improves the targeting and coordination of oscillation elimination, reduces the risk of over-cutting, and helps maintain available station output while ensuring grid-connected operation safety.

[0049] In some embodiments, step 2400, which involves performing oscillation elimination control on multiple oscillating elements within the same control level, includes: Step 2430: When there are multiple oscillating elements in the same control level, establish the intra-level control sequence of the multiple oscillating elements in the current control level according to the priority of the oscillation action time and / or the oscillation control factor.

[0050] Specifically, when multiple oscillating elements are detected within the current control level, the oscillation action time of each element and the oscillation control factor used to evaluate control priority can be obtained first, and an intra-level control sequence can be established accordingly. The oscillation action time represents the time sequence in which each protection element meets the oscillation action condition. The oscillation control factor can include at least one of oscillation amplitude, element characteristics, oscillation duration, power frequency power, and electrical position. Oscillation amplitude and oscillation duration can be used to reflect the severity of the oscillation; element characteristics can be used to distinguish the control methods of power generation units, collector lines, reactive power compensation equipment, or grid-connected related elements; power frequency power can be used to assess the potential scale of power cut-off after control; and electrical position can be used to reflect the position of the oscillating element relative to the upper-level collection point or grid connection point within the current level.

[0051] Optionally, the basic sorting can be determined based on the oscillation action time, or the sorting can be adjusted by combining one or more oscillation control factors. For example, oscillating elements with stronger negative resistance characteristics, larger oscillation amplitudes, earlier actions, longer durations, or higher contributions to oscillation are given priority, thus obtaining an intra-layer control sequence for multiple oscillating elements within the current control level. For example, oscillating elements that meet the negative resistance characteristics and exceed a preset oscillation amplitude threshold are first screened out, and then sorted according to their negative resistance characteristics from strongest to weakest; that is, the intra-layer control sequence is determined by comprehensively considering both negative resistance characteristics and oscillation amplitude.

[0052] Step 2440: Determine the control round according to the control sequence within the layer, and perform round-by-round oscillation elimination control on the oscillation element in each round.

[0053] Specifically, after obtaining the intra-layer control sequence, multiple oscillating elements within the current control level can be identified into one or more control rounds according to the intra-layer control sequence, and oscillation elimination control can be executed round by round. Specifically, the control object for this round can be selected from the beginning of the intra-layer control sequence, and the oscillating elements that need to be controlled in this round can be determined by combining the upper limit of the single-round control quantity, the type of control object, the control output status, and the station operation constraints.

[0054] It should be noted that for grid-connected power plants with three control levels—generation layer, collector layer, and grid connection layer—after one round of oscillation elimination control for the protection elements in the generation and collector layers, the oscillating elements return to normal or no longer exhibit oscillation action indicators. Furthermore, since oscillations in the grid connection layer may be caused by lower-level elements, even after one round of oscillation elimination control for the protection elements in the grid connection layer, oscillating elements in lower-level layers may still cause oscillations in the grid connection layer. Therefore, this embodiment performs only one round of oscillation elimination control for the generation and collector layers, while performing multiple rounds of oscillation elimination control for the grid connection layer, which is beneficial for improving the safety and stability of the entire system.

[0055] In this embodiment, when multiple oscillating elements exist within the same control level, the control sequence within the level is determined based on the oscillation action time and oscillation control factor. The oscillation elimination control is then executed in rounds according to this sequence. This avoids excessive control input caused by multiple oscillating elements operating simultaneously, thereby improving the precision, orderliness, and adaptability of oscillation elimination for multiple elements at the same level. It also facilitates prioritizing the handling of elements that have a more significant impact on oscillation or require more timely intervention. Furthermore, the round-robin control avoids excessive control input caused by cutting off multiple elements at once, thus reducing the risk of over-cutting and erroneous cutting.

[0056] In some embodiments, determining the control round according to the intra-layer control sequence in step 2440 includes: Step 2441: In each control round, using the preset upper limit of the single-round target control quantity as a constraint, determine the control object of this round by accumulating the target control quantity corresponding to the oscillating element according to the control sequence within the layer.

[0057] Specifically, after the start of the current control round, oscillating elements that have not yet been controlled can be selected sequentially from the control sequence within the current control level, and the target control quantity corresponding to each oscillating element can be obtained. The target control quantity can be an electrical quantity related to the power frequency, current, or voltage of the oscillating element, used to characterize the control scale that may result after controlling the oscillating element. Then, the target control quantities of candidate oscillating elements are accumulated one by one according to the control sequence within the level, and the accumulated control quantities are compared with the preset single-round target control quantity upper limit. Candidate oscillating elements that, even after being added, still do not exceed the preset single-round target control quantity upper limit can be included in the current round of control; candidate oscillating elements whose addition would cause the accumulated control quantity to exceed the preset single-round target control quantity upper limit are not included in the current control round. After determining the control object for the current round, the control output corresponding to the control object for the current round is opened to perform cutoff, blocking, load reduction, or other oscillation elimination control on the control object for the current round. At the same time, the control outputs of oscillating elements other than the control object for the current round within the same control level are kept blocked, thereby constraining the control scale of each control round.

[0058] This embodiment limits the number or scale of oscillating elements participating in each round of control by using a preset upper limit for the target control quantity in each round as a constraint, and by accumulating the target control quantity corresponding to the oscillating element according to the control sequence within the layer, thus determining the control object for this round. This avoids excessive control quantity caused by multiple oscillating elements acting intensively in the same round. Simultaneously, by only opening the control output of the control object for this round and blocking the control outputs of other unselected oscillating elements, it reduces the risk of disordered concurrent control actions at the same level, lowers the risk of over-cutting, erroneous cutting, and excessive impact on the power station output, thereby improving the precision and controllability of the round-by-round oscillation elimination control.

[0059] In some embodiments, step 2440, which involves sequentially controlling the oscillation element to eliminate oscillations, includes: Step 2442: After each control round is executed, wait for the preset inter-round delay, and reacquire the oscillation state of the uncontrolled defensive elements within the control level, or reacquire the oscillation state of all defensive elements in the subordinate control levels of the current control level.

[0060] Specifically, after the oscillation element corresponding to the current control cycle completes its cutoff, blocking, load reduction, or other oscillation elimination control, a preset inter-cycle delay can be waited for. This allows the impact of the current control action on the station's electrical quantities and oscillation state to be fully reflected, avoiding immediate entry into the next control cycle before the transient changes have stabilized. After the inter-cycle delay ends, the oscillation state of the corresponding protection element can be reacquired according to the type of the current control level.

[0061] For the power generation or collector layer, the oscillation status of uncontrolled protection elements within that control level can be reacquired to determine whether oscillations still exist in the remaining power generation units, transformer substations, collector lines, or reactive power compensation equipment. For elements that have already been controlled, since their control outputs have been activated and are in an exit or lockout state, they can no longer be considered as subsequent control objects at the current level. For the grid-connected layer, the oscillation status of all relevant protection elements in its subordinate control levels can be reacquired, such as the status of elements in the subordinate collector or power generation layers, to determine whether grid-connected layer oscillations may still be caused by subordinate elements.

[0062] Step 2443: In response to the detection of an oscillating element, proceed to the next control round based on the updated oscillation state.

[0063] Specifically, after reacquiring the updated oscillation state, it can be determined whether there are still oscillating elements in the current control level, or, in the case of grid-connected layer control, whether there are still oscillating elements in its subordinate control levels that can cause grid-connected layer oscillations. If oscillating elements are still detected, the object to be controlled can be re-determined based on the updated oscillation state. For example, the control sequence within the layer can be updated, controlled elements can be removed, the oscillation amplitude or action sequence of candidate elements can be adjusted, and the control object for the next control round can be determined in combination with the upper limit of the single-round target control quantity. Then, the next control round is entered, and the control outputs of the corresponding oscillating elements or their subordinate elements are opened round by round until the updated oscillation state indicates that the oscillation at the current level has been eliminated, or the conditions for entering other control levels or ending the control of this oscillation event are met.

[0064] It is easy to understand that the oscillation element corresponding to the updated oscillation state can be the same as or different from the uncontrolled oscillation element in the previous round, and the oscillation state of the oscillation element can be the same as or different from the oscillation state of the same oscillation element in the previous round. That is to say, after this round of control, the oscillation element that was not controlled in this round may no longer oscillate, and the defense element that did not oscillate in this round may oscillate.

[0065] Please see Figure 3 , Figure 3The diagram shows the timing logic of the round-robin control of the power generation layer in a grid-connected power station. In the power generation layer, each power generation unit or transformer-side source control terminal continuously monitors the voltage, current, and other electrical quantities of the corresponding power generation layer components, and determines whether broadband oscillations are occurring based on oscillation criteria. When multiple power generation layer components reach the oscillation action condition sequentially or simultaneously, the station-side broadband oscillation monitoring device determines the control sequence based on the oscillation action order of each power generation layer component. During the control process, each round only opens the control output of the corresponding power generation layer oscillating component, performs cut-off or exit control on it, and waits for the preset inter-round delay after that round of control. Then, the oscillation status of the remaining unremoved power generation layer elements is reassessed. If oscillating elements still exist, the process continues in the next round of sequential removal until the oscillation within the power generation layer is eliminated or there are no longer any oscillation action indicators.

[0066] Please see Figure 4 , Figure 4 The diagram shown is the timing logic diagram of the collector layer control in a grid-connected power plant. The control principle of the collector layer is the same as... Figure 3 The control principle corresponding to the timing logic of the generator layer's wheel control differs in the following ways: the types of electrical quantities can be different; the electrical quantities of the collector layer can be voltages, currents, etc., of collector layer components such as collector lines and SVG. Obviously, the control outputs corresponding to different electrical quantities are also different; the preset inter-wheel delay duration can be different, with the preset inter-wheel delay of the collector layer being... .

[0067] In addition, the collector layer has an upper limit on the single-wheel control quantity, and the upper limit of the collector layer's power frequency control quantity is [missing information]. During the control process, the upper limit of the single-round collector layer power frequency control quantity is used. To constrain this process, the oscillating elements to be cut off in this round are selected according to the control sequence, ensuring that the sum of the power frequency power of the oscillating elements controlled in each round does not exceed [a certain limit]. This allows for the elimination of collector layer oscillations while avoiding the simultaneous disconnection of too many collector lines or reactive power compensation equipment, thus reducing the risk of over-cutting.

[0068] Please see Figure 5 , Figure 5 The diagram shows the timing logic of the batch control at the grid connection layer of a grid-connected power plant. The control principle of the grid connection layer is the same as... Figure 4 The control principle corresponding to the timing logic of the collector layer's wheel control differs in that: the types of electrical quantities can be different; the electrical quantities of the grid-connected layer can be voltages and currents of grid-connected components such as grid-connected outgoing lines. Clearly, different electrical quantities correspond to different control outputs; the preset inter-wheel delay duration can also be different, with the preset inter-wheel delay of the grid-connected layer being... The upper limit of single-wheel control quantity is different; the upper limit of grid-connected layer power frequency control quantity is... During the control process, the upper limit of the single-round grid-connected layer power frequency control quantity is used. To constrain this, the protection elements at the subordinate control levels corresponding to the grid-connected oscillation elements to be cut off in this round are selected according to the control sequence, so as to ensure that the sum of the power frequency power of the oscillation elements controlled in each round does not exceed the limit. This avoids large-scale outages caused by directly cutting off grid-connected outgoing lines, and achieves refined suppression of grid-connected layer oscillations by selectively cutting off the defense components at the subordinate control level in stages.

[0069] It is easy to understand that the control type corresponding to the upper limit of the control quantity can be other types besides power frequency power, and the upper limit of the control quantity can also be different for different control layers.

[0070] This embodiment waits for a preset inter-round delay after each control round and reacquires the oscillation state of uncontrolled protected components or protected components in the control level below the grid connection layer. Based on the updated oscillation state, it determines whether to proceed to the next control round. This allows the actual vibration suppression effect after each round of control to be verified in a timely manner, preventing the control range from being expanded further before the oscillation state has stabilized or been eliminated. Simultaneously, selecting the next control target based on the updated oscillation state can eliminate components that have already been controlled or reset, and continue processing components that still oscillate in separate rounds, thereby improving the dynamic adaptability of oscillation elimination control.

[0071] In some embodiments, each protection element is equipped with an oscillation action flag and an oscillation reset flag; the oscillation control method for the above-mentioned grid-connected power station further includes step 4000, which specifically includes: After any control cycle is executed, if all oscillation elements in the current control level generate an oscillation reset flag, or if there is no oscillation action flag in the current control level, the control action of the current control level ends.

[0072] Specifically, each protected element within a grid-connected power station can be configured with an oscillation action flag to indicate its oscillation occurrence state and an oscillation reset flag to indicate its oscillation elimination state. The oscillation action flag is generated when the oscillation characteristic of the protected element meets the oscillation action condition and continues to meet the confirmation requirements. The oscillation reset flag is generated after the oscillation characteristic of the protected element falls back to the reset condition and remains for a certain period of time. After any control cycle is completed and the necessary state update is performed, the flag status of each oscillation element in the current control level can be checked. If all oscillation elements that have been controlled or are still monitored in the current control level have generated oscillation reset flags, it indicates that the oscillation in this cycle has been eliminated in this level, and the control action of this control level can be terminated. Alternatively, if no protected element in the current control level maintains an oscillation action flag, it can also be considered that this level no longer needs to continue oscillation elimination control, thereby terminating the control action of the current control level. After the control action of the current control level ends, the control action of the adjacent upper level can be opened according to the hierarchical control logic, jump to other control levels, or the control of this oscillation event can be terminated when the termination conditions are met in all levels.

[0073] This embodiment determines whether to terminate the control action of the current control level after each control cycle is executed based on the oscillation reset flag and oscillation action flag of the oscillating element within the current control level. This avoids continuing unnecessary control cycles after the oscillation at the current level has been eliminated, thereby reducing repeated cutoffs and over-control. Simultaneously, it can dynamically update the real-time oscillation status of each defense element, which helps improve the reliability of oscillation control.

[0074] In some embodiments, determining the control level corresponding to multiple protection components within a grid-connected power station in step 1000 includes: Step 1100: Obtain the topology association information of multiple protection components within the grid-connected power station.

[0075] Specifically, the primary wiring structure, equipment register, bay configuration, monitoring and control points, protection or control device configuration, and electrical connection relationships between each protection element and the grid connection point of the grid-connected power station can be obtained to form topological association information of multiple protection elements. Protection elements may include generation units, converters, transformer substations, collector lines, reactive power compensation equipment, main transformer related bays, grid-connected outgoing lines, etc.; topological association information can be used to characterize the access location of each protection element in the station, upstream and downstream connection relationships, bus or branch to which it belongs, convergence relationship with other protection elements, and electrical connection path from the generation side to the grid connection side, thereby clarifying the electrical location and interrelationship of each protection element in the grid-connected power station.

[0076] Step 1200: Based on the topology association information of the defense elements, determine multiple defense elements to different control levels, where there is a topology order relationship between different control levels.

[0077] Specifically, based on the electrical location and upstream / downstream connections of the protected components within the grid-connected power station, lower control levels can be defined as follows: components closer to the generating equipment side, used to reflect the oscillation state of the generating unit or transformer; components located within the station's collection links, used to reflect the oscillation state of the collection lines or reactive power compensation equipment; and components closer to the grid connection point or station outlet side, used to reflect the oscillation state of the grid-connected outgoing lines or the grid-connected side. Different control levels can be topologically ordered according to the electrical connection sequence from the generating side to the grid connection side, for example, forming a generating layer, a collection layer, and a grid connection layer sequentially. Therefore, in the event of multi-component or cross-level oscillations, the control objects and control sequence can be organized based on the hierarchical relationship.

[0078] On the other hand, this embodiment provides an oscillation control system for a grid-connected power station. Please refer to [link / reference]. Figure 6 The oscillation control system 60 includes: The control level determination module 601 is used to determine the control level corresponding to multiple protection components in the grid-connected power station, wherein there is a topological order relationship between different control levels; The oscillation detection and control module 602 is used to respond to the detection of an oscillating element in the defense components, and to perform hierarchical oscillation elimination control on each oscillating element according to the topological order of the control level corresponding to the oscillating element.

[0079] Please see Figure 7 , Figure 7This is a diagram illustrating the architecture of an oscillation control system for a grid-connected power station. The system mainly includes a station-side broadband oscillation monitoring device, a terminal communication aggregation device, and multiple generator unit-side source control terminal devices. The generator unit-side source control terminal devices are located at the generator unit or transformer substation side of the generator layer. They are used to collect electrical quantities such as voltage and current of generator layer components, calculate oscillation characteristics, perform local oscillation discrimination, and upload the oscillation information of each generator unit to the terminal communication aggregation device. The terminal communication aggregation device collects the oscillation information uploaded by multiple generator unit-side source control terminal devices and forwards it to the station-side broadband oscillation monitoring device. Simultaneously, it receives generator layer control commands issued by the station-side broadband oscillation monitoring device and forwards them to the corresponding source control terminal devices. The station-side broadband oscillation monitoring device collects or receives oscillation information from grid-connected outgoing lines, collector lines, SVG, and other collector layer and grid-connected layer components, and generates a hierarchical, multi-stage coordinated control strategy by integrating the oscillation states of the generator layer, collector layer, and grid-connected layer. In specific control, the broadband oscillation monitoring device on the station side can directly execute local control outputs such as collector lines and SVG, and when it is necessary to control the power generation layer components, it can send a cut-off command to the source control terminal device on the corresponding power generation unit side through the terminal communication collection device, thereby realizing information aggregation, control coordination and hierarchical and round-robin oscillation elimination between the power generation layer, collector layer and grid connection layer.

[0080] In some embodiments, the broadband oscillation monitoring device on the station side and the terminal communication collection device communicate via a multiplexed fiber optic channel, and the terminal communication collection device communicates with multiple source control terminal devices on the power generation unit side via a Generic Object Oriented Substation Event (GOOSE) ring network.

[0081] Specifically, the source control terminal device on the generator unit side can be deployed on the generator unit or transformer side to collect electrical quantities such as voltage and current of the generator layer protection components, and determine the oscillation state of the corresponding generator layer protection components based on the collected electrical quantities. The terminal communication aggregation device is used to receive information such as oscillation state, oscillation action flag, and oscillation recovery flag uploaded by each generator unit side source control terminal device, and send the aggregated generator layer oscillation information to the station side broadband oscillation monitoring device through a multiplexed fiber optic channel. The station side broadband oscillation monitoring device is used to monitor the oscillation state of the collector layer and grid-connected layer protection components, and generate layered and rounded oscillation elimination control commands based on the oscillation states of the generator layer, collector layer, and grid-connected layer. When it is necessary to control the generator layer oscillation components, the station side broadband oscillation monitoring device can send the control commands to the terminal communication aggregation device through a multiplexed fiber optic channel, and then the terminal communication aggregation device forwards the control commands to the corresponding generator unit side source control terminal device through the substation event ring network communication oriented to general objects, so that the corresponding generator layer unit can perform oscillation elimination actions such as disconnection, blocking, or load reduction.

[0082] This communication architecture enables the establishment of a hierarchical communication path between the monitoring device on the power plant side and the terminal on the power generation unit side. This allows for the centralized collection and rapid uploading of power generation layer oscillation information, and enables the reliable distribution of hierarchical and sequential control commands generated on the power plant side to the corresponding controlled objects. This improves the real-time performance and coordination of cross-device oscillation control.

[0083] In some embodiments, the station-side broadband oscillation monitoring device can communicate with multiple terminal communication collection devices, and each terminal communication collection device can communicate with multiple power generation unit-side source control terminal devices.

[0084] Specifically, based on the number of generating units, the distribution of collection lines, the grouping of transformer substations, or the partitioning of communication networks within a grid-connected power station, multiple source control terminal devices on the generating unit side can be divided into multiple terminal groups. Each terminal group corresponds to a terminal communication aggregation device. Each terminal communication aggregation device receives the oscillation status uploaded by its subordinate generating unit side source control terminal devices and sends the aggregated oscillation information to the same station-side broadband oscillation monitoring device. After receiving the information uploaded by multiple terminal communication aggregation devices, the station-side broadband oscillation monitoring device can form a full station oscillation status view covering the generating layer, collection layer, and grid connection layer, and determine the oscillation element that needs to be controlled based on the topological order of the control hierarchy. When the controlled object belongs to a generating unit side source control terminal device under a certain terminal communication aggregation device, the station-side broadband oscillation monitoring device can send the control command to the corresponding terminal communication aggregation device, which then further sends it to the target generating unit side source control terminal device.

[0085] This system architecture can adapt to application scenarios with a large number of power generation units, a wide distribution range, and many communication access points in large grid-connected power plants. It reduces the data aggregation pressure on a single communication node and facilitates expansion and deployment according to power generation unit partitioning, transmission line partitioning, or transformer grouping.

[0086] Please see Figure 8 , Figure 8 This is a main wiring diagram of a grid-connected power station. From bottom to top, the grid-connected power station mainly includes 40 35kV box-type substations for wind power, photovoltaic, and energy storage power generation units, 2 35kV SVG (Static Var Generator) units, 10 35kV collector lines, 1 220kV main transformer, and 1 220kV outgoing line, among other equipment components. In the example operating condition of the new energy power station, box-type substations #1, #2, #3, #4, #13, #14, #15, and #16, collector lines #1, #4, and #10, SVG #1, and outgoing line #1 experience broadband oscillations. Based on the above embodiment and its example operating condition, the implementation steps of this invention are as follows: Step 1: Using the transformer substations as power generation units, 40 power generation unit-side source control terminal devices are deployed on the high-voltage side of the wind power, photovoltaic, and energy storage power generation unit combiner transformer substations in the grid-connected power station to monitor the oscillation information of the 40 transformer substations in real time; a station-side broadband oscillation monitoring device is deployed on the station side to monitor the oscillation information of 10 collector lines, 2 SVG units, and one outgoing line interval of the new energy station in real time; at the same time, a terminal communication aggregation device is deployed on the station side to establish communication with the 40 transformer substation-side source control terminal devices and the station-side broadband oscillation monitoring device respectively.

[0087] Step 2: Select the power criterion and calculate the oscillation characteristics such as power oscillation amplitude and power oscillation frequency of the transformer substation, collector line, SVG, and outgoing line. The source control terminal device on the transformer substation side determines that the power oscillation amplitude of transformer substations #1, #2, #3, #4, #13, #14, #15, and #16 successively reaches the action threshold (e.g., 3MW) and the duration exceeds the confirmation delay set value (e.g., 30s). #14, transformer #15, and transformer #16 oscillate; the broadband oscillation monitoring device on the station side determines that the power oscillation amplitude of collector lines #1, #4, #10, and SVG #1 successively reaches the action threshold (e.g., 5MW) and the duration exceeds the confirmation delay setting (e.g., 40s), and the power oscillation amplitude of outgoing line #1 successively reaches the action threshold (e.g., 10MW) and the duration exceeds the confirmation delay setting (e.g., 60s), and collector lines #1, #4, #10, SVG #1, and outgoing line #1 oscillate.

[0088] Step 3: The broadband oscillation monitoring device on the station side summarizes the oscillation status of each level and component. First, it determines that oscillations have occurred in transformer substations #1, #2, #3, #4, #13, #14, #15, and #16 at the power generation level. Then, it disconnects the transformer substations one by one in turn according to the order of oscillation actions, with a waiting time between each round of control. Assuming that after the three-stage operation disconnects transformer #1, transformer #2, and transformer #3, all remaining transformer oscillations in the power generation layer are eliminated.

[0089] Step 4: When all transformer interval oscillations are eliminated, wait for the time difference delay between the power generation layer and the collector layer. The oscillation control of the collector layer components is then enabled. Assuming that collector wires #1, #4, #10, and SVG #1 are still oscillating, the oscillating collector wires or SVGs are disconnected in batches according to the order of their oscillation actions. The sum of the power frequency power of each batch disconnection of the collector wires and SVGs must not exceed the maximum control value in a single operation. Under the condition that, assuming that in one round of action the collector wire #1 and SVG #1 are cut off, all remaining collector wires and SVG oscillations in the collector layer are eliminated.

[0090] Step 5: When all collector wire and SVG interval oscillations are eliminated, wait for the time difference delay between the collector layer and the grid connection layer. Then, the oscillation control of outgoing line #1 at the grid connection layer is activated. Assuming that outgoing line #1 is still oscillating at this time, the remaining uncut collector lines or SVGs within the station are selected and switched in batches in rounds. The sum of the power frequency power of the collector lines and SVGs in each round of batch switching does not exceed the maximum control quantity in a single operation. Under the condition that, assuming that the negative resistance characteristics and the principle of prioritizing large amplitude are followed, after one round of cutting off the collector wire #4, the oscillation of the outgoing line #1 is eliminated.

[0091] Step 6: Assuming that after the oscillation control of outgoing line #1 is eliminated, only the collector line #10 oscillates again, then wait for the time difference between the grid connection layer and the generation layer. Afterwards, the oscillation control is restarted layer by layer from the generator layer components. At this point, the oscillation of the generator layer transformer has been completely eliminated, and the oscillation control of the collector layer is directly opened. The collector line #10 is cut off according to the oscillation cutoff strategy of the collector line itself. At this point, the oscillation of all layer components is eliminated, and the control of this oscillation event ends.

[0092] This embodiment also provides an electronic device, including a memory and a processor. In a specific example, the memory stores a computer program, which, when executed by the processor, implements the method of any of the above embodiments.

[0093] This embodiment also provides a computer-readable storage medium having a computer program stored thereon, the computer program being loaded by a processor to perform the steps of any of the methods in the above embodiments.

[0094] In the embodiments of this application, the storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM), etc.

[0095] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0096] The above provides a detailed description of the oscillation control method, system, and electronic equipment for a grid-connected power station provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An oscillation control method for a grid-connected power plant, characterized in that, Includes the following steps: Determine the control levels corresponding to multiple defense components within a grid-connected power station, wherein there is a topological order relationship between different control levels; In response to the detection of an oscillating element among the defense elements, hierarchical oscillation elimination control is performed on each of the oscillating elements according to the topological order of the control levels corresponding to the oscillating elements.

2. The oscillation control method for grid-connected power plants according to claim 1, characterized in that, The response to detecting the presence of an oscillating element oscillating in the defense element includes: Collect the target electrical quantities of the defense components and calculate the oscillation characteristic quantities corresponding to the target electrical quantities; The oscillation state of the defense element is determined based on the oscillation characteristic quantity and the preset oscillation action threshold value. Based on the oscillation state of each of the aforementioned defensive elements, the oscillating element among the defensive elements that is oscillating is determined.

3. The oscillation control method for grid-connected power plants according to claim 1, characterized in that, Based on the topological order of the control levels corresponding to the oscillation elements, oscillation cancellation control is performed on each of the oscillation elements, including: In the case where there are oscillating elements in the defense elements within at least two control levels, based on the topological order relationship between the at least two control levels, hierarchical oscillation elimination control is performed on the oscillating elements in different control levels, and round-robin oscillation elimination control is performed on multiple oscillating elements within the same control level.

4. The oscillation control method for grid-connected power plants according to claim 3, characterized in that, The hierarchical oscillation elimination control for oscillating elements within different control levels includes: According to the control level from low to high, the oscillation elements in each control level are subjected to hierarchical oscillation elimination control; After the current round of hierarchical oscillation elimination control is completed, if a new oscillating element or a remaining oscillating element is detected, the hierarchical oscillation elimination control steps are executed cyclically.

5. The oscillation control method for grid-connected power plants according to claim 3, characterized in that, The method of performing round-robin oscillation elimination control on multiple oscillation elements within the same control level includes: In the case of multiple oscillating elements within the same control level, an intra-level control sequence for the multiple oscillating elements in the current control level is established according to the oscillation action time and / or the priority of the oscillation control factor. The oscillation control factor includes at least one of oscillation amplitude, element characteristics, oscillation duration, power frequency power, and electrical position. The control rounds are determined according to the layer control sequence, and the oscillation element is subjected to round-by-round oscillation elimination control in turn.

6. The oscillation control method for grid-connected power plants according to claim 5, characterized in that, Determining the control round according to the intra-layer control sequence includes: In each control round, the target control quantity corresponding to the oscillating element is accumulated according to the control sequence within the layer, with the preset upper limit of the target control quantity in a single round as a constraint, to determine the control object of the current round.

7. The oscillation control method for grid-connected power plants according to claim 5 or 6, characterized in that, The step-by-step oscillation elimination control of the oscillating element includes: After each control round is executed, wait for a preset inter-round delay, and reacquire the oscillation state of the uncontrolled defensive elements within the control level, or reacquire the oscillation state of all the defensive elements in the subordinate control levels of the current control level. In response to the detection of an oscillating element, the system proceeds to the next control cycle based on the updated oscillation state.

8. The oscillation control method for grid-connected power plants according to claim 7, characterized in that, Each of the aforementioned defensive elements is equipped with an oscillation action indicator and an oscillation reset indicator; The method further includes: After any control cycle is executed, if all oscillation elements in the current control level generate an oscillation reset flag, or if there is no oscillation action flag in the current control level, the control action of the current control level ends.

9. The oscillation control method for grid-connected power plants according to claim 4, characterized in that, The control hierarchy includes a power generation layer, a power collection layer, and a grid connection layer with increasing control priority. The step of performing tiered oscillation elimination control on the oscillating elements within each control level, in ascending order of control level, includes: For the power generation layer, oscillation elimination control is performed on the defense elements of the power generation layer in sequence; For the current collector layer, oscillation cancellation control is performed sequentially on the protection elements of the current collector layer; For the grid-connected layer, the defense element in the subordinate control level corresponding to the oscillation state of the grid-connected layer performs oscillation cancellation control.

10. The oscillation control method for grid-connected power plants according to any one of claims 1 to 6, characterized in that, The determination of the control levels corresponding to multiple defense components within a grid-connected power station includes: Obtain the topology association information of multiple protection components within a grid-connected power station; Based on the topological association information of the defense elements, the multiple defense elements are assigned to different control levels.

11. An oscillation control system for a grid-connected power station, characterized in that, The oscillation control system includes: The control level determination module is used to determine the control level corresponding to multiple defense components in a grid-connected power station, wherein there is a topological order relationship between different control levels; An oscillation detection and control module is used to respond to the detection of an oscillating element in the defense components, and to perform hierarchical oscillation elimination control on each of the oscillating elements according to the topological order of the control levels corresponding to the oscillating elements.

12. An electronic device, characterized in that, It includes a memory and a processor, wherein the memory stores a computer program that, when executed by the processor, implements the method as described in any one of claims 1 to 10.

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