Broadband oscillation suppression method, device, equipment and medium for flexible direct current system

Abstract

The present invention provides a method, device, equipment, and medium for suppressing broadband oscillations in a flexible direct current system, relating to the field of power transmission technology. The method comprises: obtaining a target oscillation amplitude and a target oscillation frequency of a broadband oscillation corresponding to the flexible direct current system; when the target oscillation amplitude is within a preset amplitude range, determining an oscillation mode corresponding to an oscillation frequency range including the target oscillation frequency as a target oscillation mode; determining a modal adjustment order for each target oscillation mode based on the damping ratio range corresponding to each target oscillation mode; and adjusting each target participation factor for each target oscillation mode corresponding to the modal adjustment order based on the adjustment relationship between each target participation factor corresponding to the target oscillation mode and the damping ratio of the target oscillation mode, until the broadband oscillation meets a preset suppression condition. Compared with the method of reproducing and then adjusting fixed parameters, the present invention is more accurate, can better suppress broadband oscillations, and can also adapt to solving variable oscillation problems.

Description

Technical Field

[0001] The present invention relates to the field of power transmission technology, and in particular to a method, device, equipment and medium for suppressing broadband oscillations in a flexible direct current system. Background Art

[0002] Flexible direct current (HVDC) transmission systems (FDCs), characterized by flexible control, rapid response, and strong support capabilities, are a core technology for addressing renewable energy transmission and grid integration. However, in recent years, with the increasing penetration of renewable energy, broadband oscillations have occurred in many FDCs both domestically and internationally. These oscillations have restricted their operation and even caused long-term outages. Therefore, research is warranted to address this issue.

[0003] The broadband oscillation phenomenon in flexible DC systems has a complex mechanism, primarily encompassing the following scenarios: 1. Internal oscillation within the converter station; 2. Inter-station oscillation on the DC side of the converter station; and 3. Oscillation between the converter station and the AC system. As can be seen, broadband oscillations vary in frequency characteristics depending on their source. Furthermore, the increasing number of power electronic devices in flexible DC systems inevitably introduces new potential broadband oscillation risks.

[0004] Existing technologies struggle to effectively suppress oscillations across different frequency bands. For broadband oscillations that have already occurred, simulation analysis is often used to replicate the phenomenon. Based on the replicated state, the oscillations are then suppressed by optimizing fixed parameters. However, since the simulated results often differ from the actual situation, the suppression effect on broadband oscillations is not ideal. Furthermore, this approach struggles to adapt to changing oscillation conditions. Summary of the Invention

[0005] The present invention provides a method, apparatus, device, and medium for suppressing broadband oscillations in flexible direct current (DC) systems. This method addresses the prior art approach of suppressing oscillations by optimizing fixed parameters based on a reproduction process. However, due to discrepancies between simulated and actual results, the broadband oscillation suppression effect is not ideal. Furthermore, this approach is also difficult to adapt to variable oscillation problems. The present invention's technical solution adjusts the participation factor based on the amplitude and frequency of the broadband oscillation, providing greater accuracy than the prior art approach of reproducing and then adjusting fixed parameters. It can better suppress broadband oscillations and address variable oscillation problems.

[0006] The present invention provides a broadband oscillation suppression method applied to a flexible direct current system, comprising the following steps.

[0007] Determining multiple typical operating conditions corresponding to the flexible DC system according to actual operating condition information corresponding to the flexible DC system;

[0008] For each of the typical operating conditions, a state-space small-signal model corresponding to the flexible direct current system under the typical operating condition is established; based on the state-space small-signal model corresponding to the typical operating condition, the oscillation frequencies of the plurality of oscillation modes corresponding to the typical operating condition are calculated, and a plurality of participation factors corresponding to the plurality of oscillation modes are determined;

[0009] Obtaining a target oscillation amplitude and a target oscillation frequency of a broadband oscillation corresponding to the flexible direct current system; when the target oscillation amplitude is within a preset amplitude range, determining an oscillation mode corresponding to an oscillation frequency range including the target oscillation frequency as the target oscillation mode; the oscillation frequency range is determined based on the oscillation frequency of the corresponding oscillation mode;

[0010] Based on the damping ratio intervals corresponding to each of the target oscillation modes, the modal adjustment order of each of the target oscillation modes is determined; for each of the target oscillation modes corresponding to the modal adjustment order, based on the adjustment relationship between each target participation factor corresponding to the target oscillation mode and the damping ratio of the target oscillation mode, each of the target participation factors is adjusted until the broadband oscillation meets the preset suppression condition.

[0011] According to a broadband oscillation suppression method for a flexible direct current system provided by the present invention, the oscillation frequency range is determined by the following steps:

[0012] For each of the participation factors, determining a factor adjustment domain corresponding to the participation factor based on the engineering parameters corresponding to the flexible direct current system and the theoretical stability boundary of the state space small signal model corresponding to the participation factor;

[0013] For each of the oscillation modes, based on the factor adjustment domains corresponding to the oscillation modes and the adjustment relationships between the participation factors corresponding to the oscillation modes and the damping ratios of the oscillation modes, the participation factors corresponding to the oscillation modes are adjusted to obtain the oscillation frequency range of the oscillation frequency of the oscillation mode.

[0014] According to a broadband oscillation suppression method for a flexible DC system provided by the present invention, determining a factor adjustment domain corresponding to the participation factor based on engineering parameters corresponding to the flexible DC system and a theoretical stability boundary of a state space small signal model corresponding to the participation factor includes:

[0015] In a case where the engineering parameters include a participation factor boundary, determining a factor adjustment domain corresponding to the participation factor based on an intersection of the participation factor boundary and a theoretical stability boundary of a state space small signal model corresponding to the participation factor;

[0016] In a case where the engineering parameters do not include the participation factor boundary, the theoretical stability boundary of the state space small signal model corresponding to the participation factor is determined as the factor adjustment domain corresponding to the participation factor.

[0017] According to a broadband oscillation suppression method for a flexible DC system provided by the present invention, for each participation factor corresponding to the oscillation mode, an adjustment relationship between the participation factor and the damping ratio of the oscillation mode is determined by the following steps:

[0018] increasing or decreasing the value of the participation factor, and calculating, based on a corresponding state-space small signal model, an adjusted damping ratio of the oscillation mode after the participation factor is adjusted;

[0019] In a case where the adjusted damping ratio and the participation factor increase or decrease synchronously, determining that the adjustment relationship between the participation factor and the damping ratio of the oscillation mode is a proportional relationship;

[0020] In a case where the adjusted damping ratio and the values of the participation factor decrease or increase synchronously, it is determined that the adjustment relationship between the participation factor and the damping ratio of the oscillation mode is an inversely proportional relationship.

[0021] According to a broadband oscillation suppression method for a flexible DC system provided by the present invention, determining a modal adjustment order of each target oscillation mode based on a damping ratio interval corresponding to each target oscillation mode includes:

[0022] For each target oscillation mode, adjusting the value of the participation factor corresponding to the target oscillation mode multiple times, and determining, based on the corresponding state-space small signal model, a damping ratio range corresponding to the target oscillation mode after the participation factor is adjusted multiple times;

[0023] The target oscillation modes are sorted based on the lower limit of the damping ratio range to obtain the mode adjustment order.

[0024] According to a broadband oscillation suppression method for a flexible direct current system provided by the present invention, the preset suppression conditions include that the target oscillation amplitude is less than the lower limit of the preset amplitude range, and that the target participation factor corresponding to each target oscillation mode is adjusted;

[0025] The step of adjusting, for each target oscillation mode corresponding to the modal adjustment sequence, each target participation factor based on an adjustment relationship between each target participation factor corresponding to the target oscillation mode and the damping ratio of the target oscillation mode, until the broadband oscillation satisfies a preset suppression condition, includes:

[0026] Obtaining a participation factor order of each target participation factor corresponding to the target oscillation mode; the participation factor order is determined based on the numerical values of each target participation factor arranged from large to small;

[0027] According to the order of the participation factors, the values of the target participation factors are adjusted based on the adjustment relationship between the target participation factors and the damping ratios of the target oscillation modes, until the target oscillation amplitude of the broadband oscillation corresponding to the flexible direct current system is less than the lower limit of the preset amplitude range, or the target participation factors corresponding to each of the target oscillation modes are adjusted.

[0028] According to a method for suppressing broadband oscillation in a flexible direct current system provided by the present invention, the method further includes:

[0029] When the target oscillation amplitude is greater than the upper limit of the preset amplitude range, the broadband oscillation of the flexible DC system is suppressed based on a second suppression strategy; the second suppression strategy includes at least an active damping method and a voltage feedforward method.

[0030] The present invention also provides a broadband oscillation suppression device for a flexible direct current system, comprising the following modules:

[0031] A first determining module is configured to determine multiple typical operating conditions corresponding to the flexible direct current system according to actual operating condition information corresponding to the flexible direct current system;

[0032] An establishment module is used to establish, for each of the typical working conditions, a state-space small-signal model corresponding to the flexible direct current system under the typical working condition; based on the state-space small-signal model corresponding to the typical working condition, calculate the oscillation frequencies of the multiple oscillation modes corresponding to the typical working condition, and determine the multiple participation factors corresponding to the respective oscillation modes;

[0033] a second determination module, configured to obtain a target oscillation amplitude and a target oscillation frequency of the broadband oscillation corresponding to the flexible direct current system; and, if the target oscillation amplitude is within a preset amplitude range, determine an oscillation mode corresponding to an oscillation frequency range including the target oscillation frequency as the target oscillation mode; the oscillation frequency range is determined based on the oscillation frequency of the corresponding oscillation mode;

[0034] An adjustment module is configured to determine a modal adjustment order for each target oscillation mode based on the damping ratio interval corresponding to each target oscillation mode; and for each target oscillation mode corresponding to the modal adjustment order, adjust each target participation factor based on an adjustment relationship between each target participation factor corresponding to the target oscillation mode and the damping ratio of the target oscillation mode until the broadband oscillation meets a preset suppression condition.

[0035] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method for suppressing broadband oscillations in a flexible direct current system as described above is implemented.

[0036] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for suppressing broadband oscillations applied to a flexible direct current system as described above is implemented.

[0037] The present invention also provides a computer program product, comprising a computer program, which, when executed by a processor, implements any of the above-described methods for suppressing broadband oscillations applied to a flexible direct current system.

[0038] The present invention provides a method, apparatus, device, and medium for suppressing broadband oscillations in a flexible DC system. The method, apparatus, equipment, and medium determine, based on actual operating condition information corresponding to the flexible DC system, multiple typical operating conditions corresponding to the flexible DC system; establish, for each typical operating condition, a state-space small-signal model corresponding to the flexible DC system under the typical operating condition; calculate, based on the state-space small-signal model corresponding to the typical operating condition, the oscillation frequencies of multiple oscillation modes corresponding to the typical operating condition, and determine multiple participation factors corresponding to each oscillation mode; obtain a target oscillation amplitude and target oscillation frequency for the broadband oscillation corresponding to the flexible DC system; when the target oscillation amplitude is within a preset amplitude range, determine the oscillation mode corresponding to an oscillation frequency range including the target oscillation frequency as the target oscillation mode; determine, based on the damping ratio range corresponding to each target oscillation mode, a modal adjustment order for each target oscillation mode; and, for each target oscillation mode corresponding to the modal adjustment order, adjust each target participation factor based on the adjustment relationship between each target participation factor corresponding to the target oscillation mode and the damping ratio of the target oscillation mode until the broadband oscillation meets a preset suppression condition; wherein the oscillation frequency range is determined based on the oscillation frequency of the corresponding oscillation mode. The technical solution of the present invention adjusts the participation factor by the amplitude and frequency of the broadband oscillation, which is more accurate than the method of reproducing and then adjusting fixed parameters in the prior art, can better suppress broadband oscillations, and can also adapt to solving variable oscillation problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1This is one of the flow charts of the broadband oscillation suppression method applied to a flexible DC system provided by the present invention.

[0041] Figure 2 This is the second flow chart of the broadband oscillation suppression method applied to a flexible DC system provided by the present invention.

[0042] Figure 3 It is a structural schematic diagram of a broadband oscillation suppression device applied to a flexible direct current system provided by the present invention.

[0043] Figure 4 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0044] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0045] In view of the above problems in the prior art, the present invention provides a broadband oscillation suppression method for a flexible direct current system. Figure 1 This is one of the flow charts of the broadband oscillation suppression method for flexible direct current system provided by the present invention. Figure 1 As shown, the method includes the following:

[0046] Step 110: Determine multiple typical operating conditions corresponding to the flexible DC system according to actual operating condition information corresponding to the flexible DC system.

[0047] Specifically, the actual operating condition information corresponding to the flexible DC system can be obtained. This actual operating condition information may include the strength of the external grid corresponding to the flexible DC system, as well as the operating mode of the flexible DC system, line parameters, and the active and reactive outputs of each converter. The external grid strength can be assessed, for example, using the short-circuit ratio or other quantitative indicators. Operating modes may include, for example, AC / DC parallel operation, pure DC operation, grid-connected operation, and off-grid operation.

[0048] Furthermore, various typical operating conditions of the flexible DC system can be determined based on the actual operating condition information. It should be noted that each typical operating condition corresponds to multiple oscillation modes. In addition, a typical operating condition matrix can be constructed based on various typical operating conditions. ,in, Indicates typical working conditions. The subscripts indicate the number of typical working conditions. Indicates the total number of typical operating conditions.

[0049] Step 120: For each of the typical working conditions, a state-space small-signal model corresponding to the flexible direct current system under the typical working condition is established; based on the state-space small-signal model corresponding to the typical working condition, the oscillation frequencies of the multiple oscillation modes corresponding to the typical working condition are calculated, and the multiple participation factors corresponding to the respective oscillation modes are determined.

[0050] Specifically, for each typical working condition, a state-space small-signal model corresponding to the flexible DC system under the typical working condition can be established. The state-space small-signal model is a mathematical tool for analyzing the behavior of nonlinear circuits or systems under small-signal conditions. The establishment process of the state-space small-signal model will not be described in detail in the present embodiment. Further, the oscillation frequencies of the multiple oscillation modes corresponding to the typical working condition can be calculated based on the state-space small-signal model corresponding to the typical working condition, where the oscillation frequency It can be expressed by the following formula:

[0051]

[0052] in, Indicates that the absolute value is solved. represents the numerical solution of the imaginary part, represents the eigenvalue corresponding to the state-space small-signal model, The value of is related to the participation factor of the corresponding oscillation mode, Represents pi.

[0053] It is also possible to determine multiple participation factors corresponding to each oscillation mode based on the state space small signal model corresponding to the typical operating conditions. In addition, the value of each participation factor can be calculated. The value of the participation factor can be calculated using the following formula:

[0054]

[0055]

[0056] in, Indicates the The first oscillation mode The value of the participation factor, Indicates the The first oscillation mode The degree of participation of the participating factors, represents the total number of participation factors corresponding to each oscillation mode, Indicates the The first oscillation mode The left eigenvector of the participation factors, Indicates the oscillation mode The right eigenvector of the participating factors.

[0057] The participation factor order can be obtained by sorting the participation factors corresponding to each oscillation mode from large to small. The participation factor order represents the importance of the participation factor, and each oscillation mode and the corresponding participation factor can be expressed in the following matrix form:

[0058]

[0059] in, represents the oscillation mode, The number after represents the number of the oscillation mode, for example represents oscillation mode 2, represents the total number of oscillation modes, represents the participation factor, The number after represents the number of the participation factor. represents the participation factor 21, Represents the total number of participation factors corresponding to each oscillation mode, and in the above matrix, the participation factors corresponding to each oscillation mode are sorted according to the size of the value, for example .

[0060] Step 130: Obtain a target oscillation amplitude and a target oscillation frequency of the broadband oscillation corresponding to the flexible direct current system; when the target oscillation amplitude is within a preset amplitude range, determine an oscillation mode corresponding to an oscillation frequency range including the target oscillation frequency as the target oscillation mode; the oscillation frequency range is determined based on the oscillation frequency of the corresponding oscillation mode.

[0061] Specifically, when broadband oscillation occurs in the flexible DC system, the target oscillation amplitude and target oscillation frequency of the broadband oscillation can be obtained. Both the target oscillation amplitude and the target oscillation frequency can be obtained through instrument detection. Figure 2 This is the second flow chart of the broadband oscillation suppression method for flexible direct current system provided by the present invention. Figure 2 As shown, when the target oscillation amplitude is within a preset amplitude interval, the oscillation frequency interval in which the target oscillation frequency is located can be determined. The target oscillation frequency may be within the oscillation frequency interval corresponding to each of a plurality of oscillation modes. In this case, these plurality of oscillation modes can all be determined as target oscillation modes. The target oscillation frequency may also be within the oscillation frequency interval corresponding to only one oscillation mode. In this case, only this oscillation mode is determined as the target oscillation mode. The target oscillation frequency may also not be within any oscillation frequency interval. In this case, there is no need to suppress broadband oscillation. The preset amplitude interval can be determined as needed. For example, the preset amplitude interval can be determined as [b, a]. The upper and lower limits of the preset amplitude interval (i.e., the values of b and a) can be set in advance based on experience.

[0062] In one embodiment, the method further comprises:

[0063] When the target oscillation amplitude is greater than the upper limit of the preset amplitude range, the broadband oscillation of the flexible DC system is suppressed based on a second suppression strategy; the second suppression strategy includes at least an active damping method and a voltage feedforward method.

[0064] Specifically, assuming that the preset amplitude interval is [b, a], when the target oscillation amplitude is greater than a, the broadband oscillation of the flexible direct current system can be suppressed based on the second suppression strategy. The second suppression strategy includes at least active damping method and voltage feedforward method. The second suppression strategy can also include other methods of suppressing oscillations.

[0065] It should be noted that if the target oscillation amplitude is smaller than the lower limit of the preset amplitude range, that is, if the target oscillation amplitude is smaller than b, there is no need to suppress the broadband oscillation.

[0066] In the above embodiment, when it is difficult to effectively suppress the oscillation frequency of the flexible direct current system based on the adjustment of the participation factor, if the target oscillation amplitude is greater than the upper limit of the preset amplitude range, other methods are used to suppress the broadband oscillation, which greatly increases the success rate of suppression.

[0067] In one embodiment, the oscillation frequency interval is determined by the following steps:

[0068] For each of the participation factors, determining a factor adjustment domain corresponding to the participation factor based on the engineering parameters corresponding to the flexible direct current system and the theoretical stability boundary of the state space small signal model corresponding to the participation factor;

[0069] For each of the oscillation modes, based on the factor adjustment domains corresponding to the oscillation modes and the adjustment relationships between the participation factors corresponding to the oscillation modes and the damping ratios of the oscillation modes, the participation factors corresponding to the oscillation modes are adjusted to obtain the oscillation frequency range of the oscillation frequency of the oscillation mode.

[0070] Specifically, for each participation factor, the factor adjustment domain corresponding to the participation factor can be determined based on the engineering parameters corresponding to the flexible direct current system and the theoretical stability boundary of the state space small signal model corresponding to the participation factor. Among them, the theoretical stability boundary of the state space small signal model is: the real part of the eigenvalue corresponding to the state space small signal model is located in the left half plane of the real axis, that is, The real part of is less than zero. The factor adjustment domain corresponding to the participation factor represents the adjustable range of the participation factor.

[0071] Furthermore, for each participation factor corresponding to each oscillation mode, the value of the participation factor can be adjusted within the factor adjustment domain corresponding to the participation factor, based on the adjustment relationship between the participation factor and the damping ratio of the oscillation mode. During the process of adjusting the value of the participation factor, the oscillation frequency of the corresponding oscillation mode will change. Therefore, after adjusting the participation factors corresponding to a particular oscillation mode, the change in the oscillation frequency of the oscillation mode can be obtained, and based on this change, the oscillation frequency range corresponding to the oscillation mode can be easily determined.

[0072] In the above embodiment, by adjusting the participation factor within the factor adjustment domain through the relationship between the participation factor and the damping ratio, the oscillation frequency range of the oscillation frequency can be accurately obtained, thereby providing a basis for judging whether the broadband oscillation needs to be adjusted and how to adjust it.

[0073] In one embodiment, determining the factor adjustment domain corresponding to the participation factor based on the engineering parameters corresponding to the flexible direct current system and the theoretical stability boundary of the state space small signal model corresponding to the participation factor includes:

[0074] In a case where the engineering parameters include a participation factor boundary, determining a factor adjustment domain corresponding to the participation factor based on an intersection of the participation factor boundary and a theoretical stability boundary of a state space small signal model corresponding to the participation factor;

[0075] In a case where the engineering parameters do not include the participation factor boundary, the theoretical stability boundary of the state space small signal model corresponding to the participation factor is determined as the factor adjustment domain corresponding to the participation factor.

[0076] Specifically, the engineering parameters corresponding to the flexible DC system may or may not include participation factor boundaries. If the engineering parameters include participation factor boundaries, the factor adjustment domain corresponding to the participation factor can be determined based on the intersection of the participation factor boundaries and the theoretical stability boundaries of the state-space small-signal model corresponding to the participation factor. If the engineering parameters do not include participation factor boundaries, the theoretical stability boundaries of the state-space small-signal model corresponding to the participation factor can be directly determined as the factor adjustment domain corresponding to the participation factor.

[0077] In the above embodiment, the factor adjustment domain corresponding to the participation factor is determined based on the engineering parameters and the theoretical stability boundary, which lays a foundation for adjusting the participation factor.

[0078] Step 140: Determine a modal adjustment order for each target oscillation mode based on the damping ratio interval corresponding to each target oscillation mode; for each target oscillation mode corresponding to the modal adjustment order, adjust each target participation factor based on the adjustment relationship between each target participation factor corresponding to the target oscillation mode and the damping ratio of the target oscillation mode until the broadband oscillation meets the preset suppression condition.

[0079] Specifically, when there are multiple target oscillation modes, it is necessary to determine which target oscillation mode's corresponding participation factor should be adjusted first, and therefore the target oscillation modes need to be sorted according to the damping ratio range.

[0080] In one embodiment, determining the modal adjustment order of each target oscillation mode based on the damping ratio interval corresponding to each target oscillation mode includes:

[0081] For each target oscillation mode, adjusting the value of the participation factor corresponding to the target oscillation mode multiple times, and determining, based on the corresponding state-space small signal model, a damping ratio range corresponding to the target oscillation mode after the participation factor is adjusted multiple times;

[0082] The target oscillation modes are sorted based on the lower limit of the damping ratio range to obtain the mode adjustment order.

[0083] Specifically, for each target oscillation mode, the numerical value of the participation factor corresponding to the target oscillation mode can be adjusted multiple times. When the participation factor changes, the damping ratio of the target oscillation mode will also change. Then, the values of multiple damping ratios after the participation factor is adjusted multiple times can be determined based on the corresponding state-space small signal model, and the smallest of the multiple damping ratios is determined as the lower limit of the damping ratio interval, and the largest of the multiple damping ratios is determined as the upper limit of the damping ratio interval. Furthermore, the target oscillation modes can be sorted according to the lower limit of the damping ratio interval, that is, the target oscillation modes can be sorted in order from small to large according to the lower limit of the corresponding damping ratio interval, and the mode adjustment order can be obtained.

[0084] Furthermore, according to the mode adjustment sequence, the participation factor of the target oscillation mode with a smaller lower limit of the damping ratio range should be adjusted first.

[0085] In one embodiment, for each of the participation factors corresponding to the oscillation modes, the adjustment relationship between the participation factor and the damping ratio of the oscillation mode is determined by the following steps:

[0086] increasing or decreasing the value of the participation factor, and calculating, based on a corresponding state-space small signal model, an adjusted damping ratio of the oscillation mode after the participation factor is adjusted;

[0087] In a case where the adjusted damping ratio and the participation factor increase or decrease synchronously, determining that the adjustment relationship between the participation factor and the damping ratio of the oscillation mode is a proportional relationship;

[0088] In a case where the adjusted damping ratio and the values of the participation factor decrease or increase synchronously, it is determined that the adjustment relationship between the participation factor and the damping ratio of the oscillation mode is an inversely proportional relationship.

[0089] Specifically, the value of the participation factor can be increased or decreased, and the adjusted damping ratio of the oscillation mode after the participation factor adjustment is calculated based on the corresponding state space small signal model. It can be determined by the following formula:

[0090]

[0091] in, represents the numerical solution of the real part, Indicates square root.

[0092] It should be noted that when the value of the participation factor changes, the corresponding eigenvalue of the state space small signal model It will also change accordingly, which will affect the value of the damping ratio.

[0093] When the damping ratio and participation factor values increase or decrease synchronously after adjustment, that is, when the participation factor value increases, the damping ratio increases, and when the participation factor value decreases, the damping ratio decreases, the adjustment relationship between the participation factor and the damping ratio of the oscillation mode is determined to be proportional. It is easy to understand that a larger damping ratio indicates a higher stability of the flexible direct current system. When the adjustment relationship is proportional, the participation factor value should be increased during subsequent adjustment of the participation factor.

[0094] When the damping ratio and participation factor values decrease or increase synchronously after adjustment, that is, when the participation factor value increases, the damping ratio decreases, and when the participation factor value decreases, the damping ratio increases, the adjustment relationship between the participation factor and the damping ratio of the oscillation mode is determined to be inversely proportional. It is easy to understand that a larger damping ratio indicates a higher stability of the flexible direct current system. When the adjustment relationship is inversely proportional, the participation factor value should be reduced during subsequent adjustment.

[0095] In the above embodiment, by adjusting the value of the participation factor, the inverse proportional relationship between the participation factor and the damping ratio can be determined, so that broadband oscillation can be suppressed by subsequently adjusting the participation factor.

[0096] In one embodiment, the preset suppression condition includes that the target oscillation amplitude is less than the lower limit of the preset amplitude range, and that the target participation factor corresponding to each target oscillation mode is adjusted;

[0097] The step of adjusting, for each target oscillation mode corresponding to the modal adjustment sequence, each target participation factor based on an adjustment relationship between each target participation factor corresponding to the target oscillation mode and the damping ratio of the target oscillation mode, until the broadband oscillation satisfies a preset suppression condition, includes:

[0098] Obtaining a participation factor order of each target participation factor corresponding to the target oscillation mode; the participation factor order is determined based on the numerical values of each target participation factor arranged from large to small;

[0099] According to the order of the participation factors, the values of the target participation factors are adjusted based on the adjustment relationship between the target participation factors and the damping ratios of the target oscillation modes, until the target oscillation amplitude of the broadband oscillation corresponding to the flexible direct current system is less than the lower limit of the preset amplitude range, or the target participation factors corresponding to each of the target oscillation modes are adjusted.

[0100] Specifically, the participation factors corresponding to each oscillation mode also have a participation factor order, which reflects the degree of influence of each participation factor on the flexible DC system under that oscillation mode. Therefore, the participation factor order of each target participation factor corresponding to the target oscillation mode can be obtained. This participation factor order can be, for example, in the matrix form described in step 120. It will be readily understood that this participation factor order is determined based on the numerical values of each target participation factor, arranged from largest to smallest.

[0101] Furthermore, the target participation factors are adjusted in order of the participation factors, and the values of the target participation factors are adjusted based on the adjustment relationship between the target participation factors and the damping ratios of the target oscillation modes (if the adjustment relationship is a proportional relationship, the value of the target participation factors is increased, and if the adjustment relationship is an inverse relationship, the value of the target participation factors is decreased), until the target oscillation amplitude of the broadband oscillation corresponding to the flexible direct current system is less than the lower limit of the preset amplitude range, or until the target participation factors corresponding to each target oscillation mode are all adjusted.

[0102] For example, the order of the target participation factors corresponding to the target oscillation mode A is: participation factor 1, participation factor 2, and participation factor 3; the order of the target participation factors corresponding to the target oscillation mode B is: participation factor 4, participation factor 3, and participation factor 2. The lower limit of the damping ratio interval corresponding to the target oscillation mode A is smaller, so the target oscillation mode A is adjusted first, that is, the value of participation factor 1 is adjusted first, and it is judged whether the target oscillation amplitude is less than the lower limit of the preset amplitude interval. If it is not less than, the value of participation factor 2 is continued to be adjusted. If it is less than, the adjustment of the participation factors is terminated. If the target oscillation amplitude is still greater than the lower limit of the preset amplitude interval after all the participation factors corresponding to the target oscillation mode A are adjusted, the participation factor 4 corresponding to the target oscillation mode B is adjusted, and then it is judged whether the target oscillation amplitude is less than the lower limit of the preset amplitude interval. If it is not less than, the value of participation factor 3 is continued to be adjusted. When the target participation factors corresponding to target oscillation mode B are all adjusted, and the target oscillation amplitude is still greater than the lower limit of the preset amplitude range, since the target participation factors corresponding to each target oscillation mode have all been adjusted, no further adjustment of the participation factors is performed. It is easy to understand that when the broadband oscillation changes, and thus the target oscillation amplitude changes, the method of the present invention can be re-executed.

[0103] The present invention provides a method for suppressing broadband oscillations in a flexible DC system. The method determines, based on actual operating condition information corresponding to the flexible DC system, multiple typical operating conditions corresponding to the flexible DC system; establishes a state-space small-signal model corresponding to each typical operating condition for the flexible DC system; calculates the oscillation frequencies of multiple oscillation modes corresponding to the typical operating condition based on the state-space small-signal model corresponding to the typical operating condition, and determines multiple participation factors corresponding to each oscillation mode; obtains a target oscillation amplitude and a target oscillation frequency for the broadband oscillation corresponding to the flexible DC system; determines, when the target oscillation amplitude is within a preset amplitude range, an oscillation mode corresponding to an oscillation frequency range including the target oscillation frequency as the target oscillation mode; determines a modal adjustment order for each target oscillation mode based on the damping ratio range corresponding to each target oscillation mode; and adjusts each target participation factor for each target oscillation mode corresponding to the modal adjustment order based on the adjustment relationship between each target participation factor corresponding to the target oscillation mode and the damping ratio of the target oscillation mode, until the broadband oscillation satisfies a preset suppression condition; wherein the oscillation frequency range is determined based on the oscillation frequency of the corresponding oscillation mode. The technical solution of the present invention adjusts the participation factor by the amplitude and frequency of the broadband oscillation, which is more accurate than the method of reproducing and then adjusting fixed parameters in the prior art, can better suppress broadband oscillations, and can also adapt to solving variable oscillation problems.

[0104] The following describes a broadband oscillation suppression device for a flexible DC system provided by the present invention. The broadband oscillation suppression device for a flexible DC system described below and the broadband oscillation suppression method for a flexible DC system described above can be referenced to each other.

[0105] Figure 3 FIG. 1 is a schematic diagram of the structure of a broadband oscillation suppression device for a flexible direct current system provided by the present invention. Figure 3 As shown, the broadband oscillation suppression device 300 applied to a flexible direct current system includes the following modules:

[0106] A first determining module 310 is configured to determine multiple typical operating conditions corresponding to the flexible direct current system according to actual operating condition information corresponding to the flexible direct current system;

[0107] Establishing module 320, for establishing, for each of the typical operating conditions, a state-space small-signal model corresponding to the flexible direct current system under the typical operating condition; calculating, based on the state-space small-signal model corresponding to the typical operating condition, respective oscillation frequencies of a plurality of oscillation modes corresponding to the typical operating condition, and determining a plurality of participation factors corresponding to each of the oscillation modes;

[0108] A second determination module 330 is configured to obtain a target oscillation amplitude and a target oscillation frequency of the broadband oscillation corresponding to the flexible direct current system; if the target oscillation amplitude is within a preset amplitude range, determine an oscillation mode corresponding to an oscillation frequency range including the target oscillation frequency as the target oscillation mode; the oscillation frequency range is determined based on the oscillation frequency of the corresponding oscillation mode;

[0109] The adjustment module 340 is used to determine the modal adjustment order of each target oscillation mode based on the damping ratio interval corresponding to each target oscillation mode; for each target oscillation mode corresponding to the modal adjustment order, based on the adjustment relationship between each target participation factor corresponding to the target oscillation mode and the damping ratio of the target oscillation mode, adjust each target participation factor until the broadband oscillation meets the preset suppression condition.

[0110] In one embodiment, the broadband oscillation suppression device applied to a flexible direct current system further includes an interval determination module, which is specifically configured to:

[0111] For each of the participation factors, determining a factor adjustment domain corresponding to the participation factor based on the engineering parameters corresponding to the flexible direct current system and the theoretical stability boundary of the state space small signal model corresponding to the participation factor;

[0112] For each of the oscillation modes, based on the factor adjustment domains corresponding to the oscillation modes and the adjustment relationships between the participation factors corresponding to the oscillation modes and the damping ratios of the oscillation modes, the participation factors corresponding to the oscillation modes are adjusted to obtain the oscillation frequency range of the oscillation frequency of the oscillation mode.

[0113] In one embodiment, the interval determination module is further configured to:

[0114] In a case where the engineering parameters include a participation factor boundary, determining a factor adjustment domain corresponding to the participation factor based on an intersection of the participation factor boundary and a theoretical stability boundary of a state space small signal model corresponding to the participation factor;

[0115] In a case where the engineering parameters do not include the participation factor boundary, the theoretical stability boundary of the state space small signal model corresponding to the participation factor is determined as the factor adjustment domain corresponding to the participation factor.

[0116] In one embodiment, the broadband oscillation suppression device applied to a flexible direct current system further includes a regulation relationship determination module, which is specifically configured to:

[0117] increasing or decreasing the value of the participation factor, and calculating, based on a corresponding state-space small signal model, an adjusted damping ratio of the oscillation mode after the participation factor is adjusted;

[0118] In a case where the adjusted damping ratio and the participation factor increase or decrease synchronously, determining that the adjustment relationship between the participation factor and the damping ratio of the oscillation mode is a proportional relationship;

[0119] In a case where the adjusted damping ratio and the values of the participation factor decrease or increase synchronously, it is determined that the adjustment relationship between the participation factor and the damping ratio of the oscillation mode is an inversely proportional relationship.

[0120] In one embodiment, the adjustment module 340 is specifically configured to:

[0121] For each target oscillation mode, adjusting the value of the participation factor corresponding to the target oscillation mode multiple times, and determining, based on the corresponding state-space small signal model, a damping ratio range corresponding to the target oscillation mode after the participation factor is adjusted multiple times;

[0122] The target oscillation modes are sorted based on the lower limit of the damping ratio range to obtain the mode adjustment order.

[0123] In one embodiment, the preset suppression condition includes that the target oscillation amplitude is less than the lower limit of the preset amplitude range, and that the target participation factor corresponding to each target oscillation mode is adjusted; the adjustment module 340 is further configured to:

[0124] Obtaining a participation factor order of each target participation factor corresponding to the target oscillation mode; the participation factor order is determined based on the numerical values of each target participation factor arranged from large to small;

[0125] According to the order of the participation factors, the values of the target participation factors are adjusted based on the adjustment relationship between the target participation factors and the damping ratios of the target oscillation modes, until the target oscillation amplitude of the broadband oscillation corresponding to the flexible direct current system is less than the lower limit of the preset amplitude range, or the target participation factors corresponding to each of the target oscillation modes are adjusted.

[0126] In one embodiment, the broadband oscillation suppression device applied to a flexible direct current system further includes a suppression module, which is specifically configured to:

[0127] When the target oscillation amplitude is greater than the upper limit of the preset amplitude range, the broadband oscillation of the flexible DC system is suppressed based on a second suppression strategy; the second suppression strategy includes at least an active damping method and a voltage feedforward method.

[0128] The present invention provides a broadband oscillation suppression device for a flexible DC system. The device determines multiple typical operating conditions corresponding to the flexible DC system based on actual operating condition information corresponding to the flexible DC system; establishes a state-space small-signal model corresponding to the flexible DC system under each typical operating condition; calculates the oscillation frequencies of multiple oscillation modes corresponding to the typical operating condition based on the state-space small-signal model corresponding to the typical operating condition, and determines multiple participation factors corresponding to each oscillation mode; obtains a target oscillation amplitude and target oscillation frequency of the broadband oscillation corresponding to the flexible DC system; determines an oscillation mode corresponding to an oscillation frequency interval including the target oscillation frequency as the target oscillation mode when the target oscillation amplitude is within a preset amplitude interval; determines a modal adjustment order for each target oscillation mode based on the damping ratio interval corresponding to each target oscillation mode; and adjusts each target participation factor for each target oscillation mode corresponding to the modal adjustment order based on the adjustment relationship between each target participation factor corresponding to the target oscillation mode and the damping ratio of the target oscillation mode until the broadband oscillation meets a preset suppression condition; wherein the oscillation frequency interval is determined based on the oscillation frequency of the corresponding oscillation mode. The technical solution of the present invention adjusts the participation factor by the amplitude and frequency of the broadband oscillation, which is more accurate than the method of reproducing and then adjusting fixed parameters in the prior art, can better suppress broadband oscillations, and can also adapt to solving variable oscillation problems.

[0129] Figure 4 An example of a physical structure diagram of an electronic device is shown below. Figure 4 As shown, the electronic device may include: a processor 410, a communication interface 420, a memory 430, and a communication bus 440, wherein the processor 410, the communication interface 420, and the memory 430 communicate with each other via the communication bus 440. The processor 410 may call logic instructions in the memory 430 to execute a broadband oscillation suppression method applied to a flexible direct current system, the method including:

[0130] Determining multiple typical operating conditions corresponding to the flexible DC system according to actual operating condition information corresponding to the flexible DC system;

[0131] For each of the typical operating conditions, a state-space small-signal model corresponding to the flexible direct current system under the typical operating condition is established; based on the state-space small-signal model corresponding to the typical operating condition, the oscillation frequencies of the plurality of oscillation modes corresponding to the typical operating condition are calculated, and a plurality of participation factors corresponding to the plurality of oscillation modes are determined;

[0132] Obtaining a target oscillation amplitude and a target oscillation frequency of a broadband oscillation corresponding to the flexible direct current system; when the target oscillation amplitude is within a preset amplitude range, determining an oscillation mode corresponding to an oscillation frequency range including the target oscillation frequency as the target oscillation mode; the oscillation frequency range is determined based on the oscillation frequency of the corresponding oscillation mode;

[0133] Based on the damping ratio intervals corresponding to each of the target oscillation modes, the modal adjustment order of each of the target oscillation modes is determined; for each of the target oscillation modes corresponding to the modal adjustment order, based on the adjustment relationship between each target participation factor corresponding to the target oscillation mode and the damping ratio of the target oscillation mode, each of the target participation factors is adjusted until the broadband oscillation meets the preset suppression condition.

[0134] Furthermore, the logic instructions in the aforementioned memory 430 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product, stored in a storage medium, includes instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a mobile hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0135] On the other hand, the present invention further provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can perform the broadband oscillation suppression method for a flexible direct current system provided by the above methods, which includes:

[0136] Determining multiple typical operating conditions corresponding to the flexible DC system according to actual operating condition information corresponding to the flexible DC system;

[0137] For each of the typical operating conditions, a state-space small-signal model corresponding to the flexible direct current system under the typical operating condition is established; based on the state-space small-signal model corresponding to the typical operating condition, the oscillation frequencies of the plurality of oscillation modes corresponding to the typical operating condition are calculated, and a plurality of participation factors corresponding to the plurality of oscillation modes are determined;

[0138] Obtaining a target oscillation amplitude and a target oscillation frequency of a broadband oscillation corresponding to the flexible direct current system; when the target oscillation amplitude is within a preset amplitude range, determining an oscillation mode corresponding to an oscillation frequency range including the target oscillation frequency as the target oscillation mode; the oscillation frequency range is determined based on the oscillation frequency of the corresponding oscillation mode;

[0139] Based on the damping ratio intervals corresponding to each of the target oscillation modes, the modal adjustment order of each of the target oscillation modes is determined; for each of the target oscillation modes corresponding to the modal adjustment order, based on the adjustment relationship between each target participation factor corresponding to the target oscillation mode and the damping ratio of the target oscillation mode, each of the target participation factors is adjusted until the broadband oscillation meets the preset suppression condition.

[0140] In another aspect, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for suppressing broadband oscillations in a flexible direct current system provided by the above methods is implemented. The method comprises:

[0141] Determining multiple typical operating conditions corresponding to the flexible DC system according to actual operating condition information corresponding to the flexible DC system;

[0142] For each of the typical operating conditions, a state-space small-signal model corresponding to the flexible direct current system under the typical operating condition is established; based on the state-space small-signal model corresponding to the typical operating condition, the oscillation frequencies of the plurality of oscillation modes corresponding to the typical operating condition are calculated, and a plurality of participation factors corresponding to the plurality of oscillation modes are determined;

[0143] Obtaining a target oscillation amplitude and a target oscillation frequency of a broadband oscillation corresponding to the flexible direct current system; when the target oscillation amplitude is within a preset amplitude range, determining an oscillation mode corresponding to an oscillation frequency range including the target oscillation frequency as the target oscillation mode; the oscillation frequency range is determined based on the oscillation frequency of the corresponding oscillation mode;

[0144] Based on the damping ratio intervals corresponding to each of the target oscillation modes, the modal adjustment order of each of the target oscillation modes is determined; for each of the target oscillation modes corresponding to the modal adjustment order, based on the adjustment relationship between each target participation factor corresponding to the target oscillation mode and the damping ratio of the target oscillation mode, each of the target participation factors is adjusted until the broadband oscillation meets the preset suppression condition.

[0145] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0146] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0147] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A broadband oscillation suppression method for a flexible DC system, characterized in that: include: Determining multiple typical operating conditions corresponding to the flexible DC system according to actual operating condition information corresponding to the flexible DC system; For each of the typical operating conditions, a state-space small-signal model corresponding to the flexible direct current system under the typical operating condition is established; based on the state-space small-signal model corresponding to the typical operating condition, the oscillation frequencies of the plurality of oscillation modes corresponding to the typical operating condition are calculated, and a plurality of participation factors corresponding to the plurality of oscillation modes are determined; Obtaining a target oscillation amplitude and a target oscillation frequency of a broadband oscillation corresponding to the flexible direct current system; when the target oscillation amplitude is within a preset amplitude range, determining an oscillation mode corresponding to an oscillation frequency range including the target oscillation frequency as the target oscillation mode; The oscillation frequency interval is determined based on the oscillation frequency of the corresponding oscillation mode; Based on the damping ratio intervals corresponding to each of the target oscillation modes, the modal adjustment order of each of the target oscillation modes is determined; for each of the target oscillation modes corresponding to the modal adjustment order, based on the adjustment relationship between each target participation factor corresponding to the target oscillation mode and the damping ratio of the target oscillation mode, each of the target participation factors is adjusted until the broadband oscillation meets the preset suppression condition.

2. The broadband oscillation suppression method for flexible direct current system according to claim 1, characterized in that: The oscillation frequency interval is determined by the following steps: For each of the participation factors, determining a factor adjustment domain corresponding to the participation factor based on the engineering parameters corresponding to the flexible direct current system and the theoretical stability boundary of the state space small signal model corresponding to the participation factor; For each of the oscillation modes, based on the factor adjustment domains corresponding to the oscillation modes and the adjustment relationships between the participation factors corresponding to the oscillation modes and the damping ratios of the oscillation modes, the participation factors corresponding to the oscillation modes are adjusted to obtain the oscillation frequency range of the oscillation frequency of the oscillation mode.

3. The broadband oscillation suppression method for flexible DC system according to claim 2, characterized in that: The determining of the factor adjustment domain corresponding to the participation factor based on the engineering parameters corresponding to the flexible direct current system and the theoretical stability boundary of the state space small signal model corresponding to the participation factor includes: In a case where the engineering parameters include a participation factor boundary, determining a factor adjustment domain corresponding to the participation factor based on an intersection of the participation factor boundary and a theoretical stability boundary of a state space small signal model corresponding to the participation factor; In a case where the engineering parameters do not include the participation factor boundary, the theoretical stability boundary of the state space small signal model corresponding to the participation factor is determined as the factor adjustment domain corresponding to the participation factor.

4. The broadband oscillation suppression method for flexible direct current system according to claim 2, characterized in that: For each of the participation factors corresponding to the oscillation modes, the adjustment relationship between the participation factor and the damping ratio of the oscillation mode is determined by the following steps: increasing or decreasing the value of the participation factor, and calculating, based on a corresponding state-space small signal model, an adjusted damping ratio of the oscillation mode after the participation factor is adjusted; In a case where the adjusted damping ratio and the participation factor increase or decrease synchronously, determining that the adjustment relationship between the participation factor and the damping ratio of the oscillation mode is a proportional relationship; In a case where the adjusted damping ratio and the values of the participation factor decrease or increase synchronously, it is determined that the adjustment relationship between the participation factor and the damping ratio of the oscillation mode is an inversely proportional relationship.

5. The broadband oscillation suppression method for a flexible direct current system according to any one of claims 2 to 4, characterized in that: The determining of the modal adjustment order of each target oscillation mode based on the damping ratio intervals corresponding to each target oscillation mode includes: For each target oscillation mode, adjusting the value of the participation factor corresponding to the target oscillation mode multiple times, and determining, based on the corresponding state-space small signal model, a damping ratio range corresponding to the target oscillation mode after the participation factor is adjusted multiple times; The target oscillation modes are sorted based on the lower limit of the damping ratio range to obtain the mode adjustment order.

6. The broadband oscillation suppression method for flexible DC system according to claim 5, characterized in that: The preset suppression conditions include that the target oscillation amplitude is less than the lower limit of the preset amplitude range, and that the target participation factors corresponding to each target oscillation mode are adjusted; The step of adjusting, for each target oscillation mode corresponding to the modal adjustment sequence, each target participation factor based on an adjustment relationship between each target participation factor corresponding to the target oscillation mode and the damping ratio of the target oscillation mode, until the broadband oscillation satisfies a preset suppression condition, includes: Obtaining a participation factor order of each target participation factor corresponding to the target oscillation mode; the participation factor order is determined based on the numerical values of each target participation factor arranged from large to small; According to the order of the participation factors, the values of the target participation factors are adjusted based on the adjustment relationship between the target participation factors and the damping ratios of the target oscillation modes, until the target oscillation amplitude of the broadband oscillation corresponding to the flexible direct current system is less than the lower limit of the preset amplitude range, or the target participation factors corresponding to each of the target oscillation modes are adjusted.

7. The broadband oscillation suppression method for a flexible DC system according to claim 6, characterized in that: The method further comprises: When the target oscillation amplitude is greater than the upper limit of the preset amplitude range, the broadband oscillation of the flexible DC system is suppressed based on a second suppression strategy; the second suppression strategy includes at least an active damping method and a voltage feedforward method.

8. A broadband oscillation suppression device for a flexible direct current system, characterized in that: include: A first determining module is configured to determine multiple typical operating conditions corresponding to the flexible direct current system according to actual operating condition information corresponding to the flexible direct current system; An establishment module is used to establish, for each of the typical working conditions, a state-space small-signal model corresponding to the flexible direct current system under the typical working condition; based on the state-space small-signal model corresponding to the typical working condition, calculate the oscillation frequencies of the multiple oscillation modes corresponding to the typical working condition, and determine the multiple participation factors corresponding to the respective oscillation modes; a second determination module, configured to obtain a target oscillation amplitude and a target oscillation frequency of the broadband oscillation corresponding to the flexible direct current system; and, when the target oscillation amplitude is within a preset amplitude range, determine an oscillation mode corresponding to an oscillation frequency range including the target oscillation frequency as the target oscillation mode; The oscillation frequency interval is determined based on the oscillation frequency of the corresponding oscillation mode; An adjustment module is configured to determine a modal adjustment order for each target oscillation mode based on the damping ratio interval corresponding to each target oscillation mode; and for each target oscillation mode corresponding to the modal adjustment order, adjust each target participation factor based on an adjustment relationship between each target participation factor corresponding to the target oscillation mode and the damping ratio of the target oscillation mode until the broadband oscillation meets a preset suppression condition.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the broadband oscillation suppression method applied to a flexible direct current system as claimed in any one of claims 1 to 7 is implemented.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for suppressing broadband oscillations applied to a flexible direct current system as claimed in any one of claims 1 to 7 is implemented.

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