Wind power converter oscillation characteristic suppression method, system and equipment based on broadband impedance scanning and storage medium

Abstract

The invention discloses a wind power converter oscillation characteristic suppression method, system and device based on broadband impedance scanning and a storage medium, and relates to the technical field of wind power grid-connected control, and the method comprises the steps: based on grid-connected steady-state small signal voltage disturbance injection, respectively extracting broadband response data of positive sequence impedance and negative sequence impedance, and constructing a machine end broadband impedance model; constructing an impedance phase and amplitude matching criterion based on the broadband impedance model in combination with the power grid side equivalent impedance, identifying risk frequency bands of subsynchronous and super-synchronous oscillation, and determining a dynamic influence interval related to the phase-locked loop bandwidth; adjusting a phase-locked loop bandwidth and a filtering parameter based on a risk frequency band and a dynamic influence interval, and executing d / q control link collaborative constraint in combination with a leakage matrix parameter; according to the method, accurate modeling of positive and negative sequence impedance of the wind power converter and bandwidth adaptive vibration suppression control are realized, and the stability and the anti-oscillation capability of the system are improved.

Description

Technical Field

[0001] This invention relates to the field of wind power grid connection control technology, specifically to a method, system, device, and storage medium for suppressing the oscillation characteristics of wind power converters based on wideband impedance scanning. Background Technology

[0002] With the continuous growth of wind farm installed capacity and the rapid increase in the proportion of power electronics, wind power converters have become the main dynamic control unit in the power grid. The converter achieves independent regulation of active and reactive power through power electronic switching devices. The dynamic characteristics are affected by factors such as control parameters, sampling period, filtering links and phase-locked loop bandwidth. Under the condition of high penetration of new energy access, the power system exhibits significant weak grid characteristics. The electromagnetic inertia effect of traditional synchronous generators is weakened, and the impedance characteristics of the power grid are gradually dominated by the converter control link, forming a multi-frequency coupling relationship between voltage and current. When multiple types of converter devices are running at the same time, the matching state between the terminal impedance and the equivalent impedance of the power grid directly affects the frequency domain stability of the system, especially in the subsynchronous and supersynchronous frequency bands where oscillations are prone to occur.

[0003] Existing impedance scanning and modeling techniques still face several challenges in practical engineering applications. In broadband modeling, positive-sequence and negative-sequence impedances are often affected by sampling errors, control delays, and non-ideal filter characteristics, causing cross-responses between positive and negative-sequence components. This affects the accuracy of impedance characteristic identification. Sequence component leakage can cause shifts in impedance phase and amplitude on the complex plane, making the identification results of risky frequency bands unstable. Traditional modeling methods mainly employ frequency point fitting and amplitude normalization, but these methods suffer from discontinuous phase responses in the high-frequency range and gaps in spectrum stitching, failing to comprehensively reflect the impedance distribution of the system over a wide frequency range.

[0004] Oscillation risk analysis often uses impedance amplitude or phase alone as criteria, making it difficult to consider the combined matching relationship of the two simultaneously. Therefore, it has limitations in determining the risk range of subsynchronization and supersynchronization. Phase-locked loop (PLL) control plays the role of voltage phase synchronization and frequency tracking in converter systems. However, traditional designs often use fixed bandwidth parameters, which cannot be dynamically corrected when the grid impedance changes or the system coupling increases. This can easily lead to a decrease in phase margin and cause unstable oscillations. Filter parameters and sampling period also affect the sensitivity of bandwidth adjustment, limiting the dynamic performance of the PLL in the high-frequency range. The d / q decoupling of the current control loop usually operates independently of the PLL. When the parameters are not adjusted synchronously, coordinate rotation errors will occur, causing the current reference signal to deviate from the actual feedback signal, further affecting the symmetry of the positive and negative sequence impedances and the frequency domain stability. Summary of the Invention

[0005] In view of the above-mentioned problems, the present invention is proposed.

[0006] Therefore, the technical problem solved by this invention is that existing wideband impedance analysis methods for wind power converters have problems such as easy coupling leakage between positive and negative sequence components, insufficient impedance modeling accuracy, reliance on a single phase or amplitude criterion for risk band identification, sluggish response of phase-locked loop bandwidth adjustment, and asynchronous d / q control loop parameters. The accuracy of impedance matching and dynamic stability assessment in the wideband domain is low, making it difficult to achieve real-time coordinated control of the generator terminal impedance and the grid equivalent impedance, as well as effective suppression of oscillation characteristics.

[0007] To address the aforementioned technical problems, this invention provides the following technical solution: a method for suppressing the oscillation characteristics of wind power converters based on wideband impedance scanning, comprising: based on the small-signal voltage disturbance injection in grid-connected steady state, extracting wideband response data of positive-sequence impedance and negative-sequence impedance respectively, and constructing a wideband impedance model at the generator terminal; based on the wideband impedance model, constructing an impedance phase and amplitude matching criterion in combination with the grid-side equivalent impedance, identifying the risk frequency bands of subsynchronous and supersynchronous oscillations, and determining the dynamic influence range related to the phase-locked loop bandwidth; based on the risk frequency bands and the dynamic influence range, adjusting the phase-locked loop bandwidth and filtering parameters, and performing collaborative constraints of the d / q control loop in combination with the leakage matrix parameters.

[0008] As a preferred embodiment of the wind power converter oscillation characteristic suppression method based on wideband impedance scanning described in this invention, the small-signal voltage disturbance injection includes: superimposing a positive-sequence disturbance signal and a negative-sequence disturbance signal with controllable amplitude onto the generator terminal voltage under the grid-connected steady state of the converter; collecting the generator terminal current response before and after the disturbance; performing synchronous rotating coordinate transformation on the three-phase signal; decomposing the sampled signal into positive-sequence and negative-sequence components; obtaining the complex ratio value of each injection point; forming wideband response curves of positive-sequence impedance and negative-sequence impedance; and characterizing the voltage and current coupling characteristics of the converter in the low-frequency, subsynchronous, and supersynchronous frequency bands.

[0009] As a preferred embodiment of the wind power converter oscillation characteristic suppression method based on wideband impedance scanning described in this invention, the wideband impedance model at the generator terminal includes: interpolating and fitting positive-sequence impedance and negative-sequence impedance data in the frequency domain to establish a frequency response matrix; extracting the real and imaginary impedance parameters respectively during the modeling process and performing composite normalization processing, and continuously splicing the impedance characteristics of each frequency point on the frequency axis.

[0010] As a preferred embodiment of the wind power converter oscillation characteristic suppression method based on wideband impedance scanning described in this invention, the impedance phase and amplitude matching criteria include: constructing a matching function based on the phase and amplitude relationship between the generator terminal wideband impedance model and the grid-side equivalent impedance in the complex plane; obtaining the phase difference and amplitude ratio in real time; when the amplitude ratio approaches 1 and the phase difference approaches 180°, determining the current frequency point as a potential oscillation risk point; performing cluster analysis on all risk points to form a continuous risk frequency band interval, distinguishing risk areas belonging to the subsynchronous frequency band and the supersynchronous frequency band, and providing phase-locked loop parameter adjustment constraint boundaries.

[0011] As a preferred embodiment of the wind power converter oscillation characteristic suppression method based on wideband impedance scanning described in this invention, the dynamic influence range includes: establishing a mapping relationship between bandwidth adjustment and impedance phase change based on the phase response among phase-locked loop bandwidth, filter cutoff frequency, and sampling period; defining the frequency point corresponding to the current bandwidth as being within the dynamic influence range when the bandwidth adjustment causes the impedance phase margin to decrease to a preset stable threshold; and obtaining the adjustable bandwidth range and the allowable variation range of filter parameters by analyzing the response of the frequency points within the dynamic influence range.

[0012] As a preferred embodiment of the wind power converter oscillation characteristic suppression method based on wideband impedance scanning described in this invention, the leakage matrix parameters include: constructing a two-dimensional complex matrix describing the positive-sequence and negative-sequence coupling characteristics, defining matrix elements to represent the ratio of positive-sequence current leakage to the negative-sequence channel and the ratio of negative-sequence current leakage to the positive-sequence channel; the matrix parameters are obtained by performing frequency response matrix analysis on the generator terminal sampled signal; when the amplitude of the cross term in the leakage matrix is ​​greater than a set leakage threshold, the phase-locked loop bandwidth and filter parameters are reconstructed in tandem; the leakage components are compensated and corrected through matrix inversion to reduce inter-sequence coupling errors.

[0013] As a preferred embodiment of the wind power converter oscillation characteristic suppression method based on wideband impedance scanning described in this invention, the d / q control link collaborative constraint includes: after leakage matrix compensation and phase-locked loop bandwidth adjustment, synchronously updating the gain parameters of the d-axis and q-axis current control links, real-time calibrating the rotation angle and current reference coordinates of the d / q decoupling matrix, and performing vector reconstruction of voltage and current in a synchronously rotating coordinate system to ensure that the corrected positive-sequence impedance and negative-sequence impedance maintain symmetry in the frequency domain distribution.

[0014] Another objective of this invention is to provide a wind power converter oscillation characteristic suppression system based on wideband impedance scanning. This system can achieve independent modeling and dynamic correction of positive-sequence and negative-sequence impedances through wideband impedance modeling at the generator terminal, oscillation risk identification, and phase-locked loop coordinated control. This solves the problems of current wind power converter impedance identification being easily affected by sequence component leakage, unstable risk band determination, and lag in control loop bandwidth adjustment.

[0015] As a preferred embodiment of the wind power converter oscillation characteristic suppression system based on wideband impedance scanning described in this invention, it includes: a generator-end wideband impedance modeling module, an oscillation risk identification module, and a phase-locked loop collaborative control module; the generator-end wideband impedance modeling module is used to perform small-signal voltage disturbance injection under the grid-connected steady state of the converter, collect positive-sequence and negative-sequence voltage and current data, complete synchronous rotating coordinate transformation, obtain complex ratio values ​​to obtain frequency response data of positive-sequence and negative-sequence impedances, and construct a generator-end wideband impedance model based on real and imaginary part parameters; the oscillation risk identification module is used to combine the generator-end wideband impedance model with the grid... The equivalent impedance is used to construct impedance phase and amplitude matching criteria, and the impedance amplitude ratio and phase difference are analyzed in real time. Frequency points with amplitude ratios approaching 1 and phase differences approaching 180° are identified as potential oscillation risk points. The identified frequency points are clustered to form subsynchronous and supersynchronous risk frequency bands, and the dynamic influence range related to the phase-locked loop bandwidth is determined. The phase-locked loop collaborative control module is used to adjust the phase-locked loop bandwidth and filtering parameters based on the identified risk frequency bands and dynamic influence ranges, construct a leakage matrix describing the positive-sequence and negative-sequence coupling characteristics, perform matrix inversion compensation, and synchronously update the gain parameters of the d-axis and q-axis current control links.

[0016] Another object of the present invention is to provide a wind power converter oscillation characteristic suppression device based on wideband impedance scanning, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps of the wind power converter oscillation characteristic suppression method based on wideband impedance scanning.

[0017] Another object of the present invention is to provide a storage medium for suppressing the oscillation characteristics of a wind power converter based on wideband impedance scanning, wherein a computer program is stored thereon, and when the computer program is executed by a processor, the steps of the method for suppressing the oscillation characteristics of a wind power converter based on wideband impedance scanning are implemented.

[0018] The beneficial effects of this invention are as follows: The wind power converter oscillation characteristic suppression method based on wideband impedance scanning provided by this invention achieves continuous and high-precision characterization of terminal impedance through wideband modeling of positive and negative sequence impedances, accurately identifies subsynchronous and supersynchronous risk frequency bands through complex plane amplitude and phase matching criteria, and achieves dynamic correction of impedance distribution through the linkage of phase-locked loop bandwidth and filter parameters combined with leakage matrix and d / q control constraints. This invention achieves better results in terms of impedance identification accuracy, risk frequency band determination reliability, system stability and adaptability. Attached Figure Description

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

[0020] Figure 1 The flowchart shows the overall process of the wind power converter oscillation characteristic suppression method based on wideband impedance scanning provided in Embodiment 1 of the present invention.

[0021] Figure 2 The impedance characteristic diagram of a direct-drive wind turbine under operating condition 1 is provided for the wind power converter oscillation characteristic suppression method based on wideband impedance scanning in Embodiment 2 of the present invention.

[0022] Figure 3 The impedance characteristic diagram of a direct-drive wind turbine under operating condition 2 is provided for the wind power converter oscillation characteristic suppression method based on wideband impedance scanning in Embodiment 2 of the present invention.

[0023] Figure 4 The impedance characteristic diagram of a direct-drive wind turbine under operating condition 3 is provided for the wind power converter oscillation characteristic suppression method based on wideband impedance scanning in Embodiment 2 of the present invention. Detailed Implementation

[0024] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0025] Example 1, referring to Figure 1 As one embodiment of the present invention, a method for suppressing the oscillation characteristics of a wind power converter based on wideband impedance scanning is provided, comprising:

[0026] S1: Based on the small-signal voltage disturbance injection in grid-connected steady state, the broadband response data 10 of positive sequence impedance and negative sequence impedance are extracted respectively, and the broadband impedance model 100 of the machine terminal is constructed.

[0027] Furthermore, the small-signal voltage disturbance injection includes superimposing a positive-sequence disturbance signal and a negative-sequence disturbance signal with controllable amplitude onto the generator terminal voltage under the grid-connected steady state of the converter, collecting the generator terminal current response before and after the disturbance, performing synchronous rotating coordinate transformation on the three-phase signal 11, decomposing the sampled signal into positive-sequence and negative-sequence components, obtaining the complex ratio value of each injection point, forming wideband response curves of positive-sequence impedance and negative-sequence impedance, characterizing the voltage and current coupling characteristics of the converter in the low-frequency, subsynchronous and supersynchronous frequency bands.

[0028] It should be noted that the wideband impedance model 100 at the machine end includes: interpolating and fitting positive-sequence impedance and negative-sequence impedance data in the frequency domain to establish a frequency response matrix; extracting the real and imaginary impedance parameters respectively during the modeling process and performing composite normalization processing, and continuously splicing the impedance features of each frequency point on the frequency axis.

[0029] Under grid-connected steady-state conditions, injection frequency points ranging from 2.5Hz to 1000Hz are selected. Positive and negative sequence voltage disturbance signals are superimposed point by point. The three-phase current response is recorded using a synchronous sampling device. Park transform is performed on the sampled signals and positive and negative sequence components are extracted to obtain the complex ratio value of each frequency point. Frequency point densification and curve fitting are performed according to the frequency distribution interval to generate a high-resolution wideband impedance model. Imaginary part compensation is performed to reduce the phase shift caused by control delay.

[0030] Reducing phase shift caused by control delay includes setting a phase shift correction criterion, expressed as: , in, This indicates that the phase-locked loop (PLL) is in the first... The phase offset correction at each injection frequency point is used to correct phase deviations caused by PLL lockout delay or signal noise. This is an operator that determines the optimal phase correction by minimizing the error function. This indicates that the phase angle is estimated based on the PLL. And introduce phase correction amount The order component extraction matrix is ​​used for transformations between the abc coordinate system and positive / negative ordered rotating coordinate systems. Indicates the voltage at the three-camera terminals on the first... The vector values ​​of each sampling point This represents the theoretical positive-sequence and negative-sequence voltage component vectors at the injection frequency. This represents the squared form of the L2 norm, used to calculate the Euclidean distance between the transformed output and the theoretical order components. The smaller the value, the better the phase correction effect. It represents the angular frequency of the small-signal voltage disturbance injection, which is the corresponding frequency sampling point in the wideband impedance scan.

[0031] It should also be noted that by adopting a positive / negative sequence injection separation and wideband complex ratio fitting strategy, the continuous description of the terminal impedance in multiple frequency bands is achieved, ensuring the phase consistency of frequency domain data at the junction of subsynchronous and supersynchronous states.

[0032] S2: Based on the broadband impedance model, and combined with the equivalent impedance of the power grid side, an impedance phase and amplitude matching criterion is constructed 200 to identify the risk frequency bands of subsynchronous and supersynchronous oscillations 20, and to determine the dynamic influence range related to the bandwidth of the phase-locked loop 21.

[0033] Furthermore, the impedance phase and amplitude matching criterion 200 includes constructing a matching function based on the phase and amplitude relationship between the generator-side broadband impedance model 100 and the grid-side equivalent impedance in the complex plane, and obtaining the phase difference and amplitude ratio in real time; when the amplitude ratio approaches 1 and the phase difference approaches 180°, the current frequency point is determined to be a potential oscillation risk point; cluster analysis is performed on all risk points to form a continuous risk frequency band 20 interval, distinguishing risk areas belonging to the subsynchronous frequency band and the supersynchronous frequency band, and providing phase-locked loop parameter adjustment constraint boundaries.

[0034] It should be noted that the dynamic influence interval 21 includes establishing a mapping relationship between bandwidth adjustment and impedance phase change based on the phase response among the phase-locked loop bandwidth, filter cutoff frequency, and sampling period; when the bandwidth adjustment causes the impedance phase margin to drop to a preset stable threshold, the frequency point corresponding to the current bandwidth is defined as being in the dynamic influence interval 21; by performing response analysis on the frequency points within the dynamic influence interval 21, the adjustable bandwidth range and the allowable variation range of the filter parameters are obtained.

[0035] It should be noted that, firstly, under steady-state operating conditions, a small-signal voltage disturbance is injected into the wind power converter. The three-phase signal 11 at the generator terminal is obtained through synchronous sampling. The positive and negative sequence impedances are acquired and a complex plane matching relationship is established with the equivalent impedance of the grid. The impedance phase difference and amplitude ratio are obtained. The phase difference and amplitude ratio at each injection frequency point are solved and monitored in real time. When the amplitude ratio approaches 1 and the phase difference approaches 180°, it indicates that the generator terminal and grid impedances form an anti-phase coupling relationship at the current frequency, and the current frequency point is determined to be in the potential oscillation risk range.

[0036] Frequency clustering and risk density analysis were performed on all risk points. A sliding window aggregation method was used to form 20 continuous risk frequency bands, where the low-frequency part corresponds to the subsynchronous oscillation region and the high-frequency part corresponds to the supersynchronous oscillation region. For each risk interval, its center frequency and boundary bandwidth were extracted to generate a set of 20 risk frequency bands.

[0037] It should also be noted that the dynamic influence interval 21 includes, , in, This indicates the phase-locked loop (PLL) at the injection frequency. The phase response function, The angular frequency that represents the bandwidth of the phase-locked loop. This indicates the cutoff angular frequency of the filter. Indicates the sampling period.

[0038] It should also be noted that the boundary of the dynamic influence interval 21 is adaptively defined according to the sampling resolution of the wind power converter in grid-connected operation. By comparing the broadband response curves under different frequency bands, the bandwidth configuration of the phase-locked loop is automatically corrected to keep the phase margin within the safe threshold.

[0039] S3: Based on the risk frequency band 20 and the dynamic influence interval 21, adjust the phase-locked loop bandwidth and filter parameters, and combine the leakage matrix parameter 300 to perform d / q control link coordination constraints.

[0040] Furthermore, the leakage matrix parameter 300 includes constructing a two-dimensional complex matrix describing the coupling characteristics of positive and negative sequences, defining matrix elements to represent the ratio of positive sequence current leakage to the negative sequence channel and the ratio of negative sequence current leakage to the positive sequence channel, respectively; the matrix parameters are obtained by performing frequency response matrix analysis on the sampled signal at the machine end; when the amplitude of the cross term in the leakage matrix is ​​greater than the set leakage threshold, the linkage reconstruction of the phase-locked loop bandwidth and filtering parameters is triggered; the leakage component is compensated and corrected through matrix inversion to reduce inter-sequence coupling error.

[0041] It should be noted that the collaborative constraints of the d / q control loop include: after the leakage matrix compensation and phase-locked loop bandwidth adjustment are completed, the gain parameters of the d-axis and q-axis current control loops are updated synchronously, the rotation angle and current reference coordinates of the d / q decoupling matrix are calibrated in real time, and the voltage and current are reconstructed in a synchronous rotating coordinate system so that the corrected positive-sequence impedance and negative-sequence impedance maintain symmetry in the frequency domain distribution.

[0042] The leakage matrix is ​​represented as: , in, Indicates the injection frequency at the machine end. The broadband leakage matrix below, Indicates injection frequency The positive sequence current component below, Indicates the injection frequency at the machine end. The negative sequence current component below, Indicates the injection frequency at the machine end. The positive sequence voltage component below, Indicates the injection frequency at the machine end. The positive sequence voltage component.

[0043] It should also be noted that leakage matrix compensation is expressed as: , in, Represents the broadband leakage matrix at the machine end. The result of the inverse matrix operation, This represents the estimated positive sequence current after broadband leakage compensation. This represents the estimated negative sequence current after broadband leakage compensation. This represents the undecoupled, raw machine-side current sequence component. Indicates the injection frequency The positive sequence wideband impedance of the machine terminal after leakage compensation. Indicates the injection frequency The estimated positive sequence current after broadband leakage compensation.

[0044] Example 2, refer to Figures 2-4 As an embodiment of the present invention, a method for suppressing the oscillation characteristics of wind power converters based on wideband impedance scanning is provided. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments.

[0045] First, based on the hardware-in-the-loop simulation of the new energy generator unit 6.x series, a detailed switching model was adopted. The operating conditions of the new energy generator unit should be set according to Table 1. If time permits, operating conditions with active power output of 10%, 30%, 40%, 60%, 80%, and 90% can be considered. The impedance scan of the new energy generator unit was performed, and the positive sequence impedance and negative sequence impedance of the new energy generator unit in the range of 2.5Hz-1000Hz were given.

[0046]

[0047] Table 1 Simulation Operating Conditions of Impedance Characteristics of New Energy Units

[0048] The sampling frequency is no less than 5kHz, and the impedance frequency intervals are: 2.5Hz-10Hz with a step size of 0.1Hz; 10Hz-100Hz with a step size of 1Hz; and 100Hz-1000Hz with a step size of 10Hz. The impedance is scanned using a voltage perturbation injection method. The perturbation voltage signal is divided into positive-sequence and negative-sequence signals, and the perturbation voltage amplitude is 3% of the rated voltage amplitude.

[0049] Operating Condition 1: As per reference Figure 2 As shown, under the current operating conditions, the converter's output active power is 100% of the rated power, that is, it is in full-load operation, and the output reactive power is 30% of the rated power.

[0050] Operating Condition 2: As per reference Figure 3 As shown, under the current operating conditions, the converter's output active power is 100% of the rated power, that is, it is in full-load operation, and the output reactive power is 0% of the rated power.

[0051] Operating Condition 3: As per reference Figure 4 As shown, under the current operating conditions, the converter's output active power is 70% of the rated power, that is, it is in full-load operation, and the output reactive power is 30% of the rated power.

[0052] Experimental Results: Under a hardware-in-the-loop simulation test environment with a short-circuit ratio of 1.5 at the turbine terminals, the tested direct-drive wind turbine can operate stably under all test conditions. The tested direct-drive wind turbine can operate continuously connected to the grid during low-voltage ride-through, high-voltage ride-through, continuous high-low voltage ride-through, and small external reactive power disturbance tests, and can perform dynamic reactive power support and active power maintenance according to the corresponding requirements. Using the test data from low-voltage ride-through, high-voltage ride-through, and continuous high-low voltage ride-through, the control parameters of the tested direct-drive wind turbine are comprehensively evaluated, and the control parameters meet the performance optimization requirements for grid connection of new energy in northern Shaanxi. A frequency scan of the impedance characteristics of the direct-drive wind turbine was conducted, providing positive-sequence and negative-sequence impedances in the range of 2.5Hz-1000Hz. By optimizing the control parameters or improving the control strategy, impedance reshaping was achieved, suppressing wideband oscillations, and the impedance characteristics meet the operational safety requirements.

[0053] Example 3, an embodiment of the present invention, provides a wind power converter oscillation characteristic suppression system based on wideband impedance scanning, including a generator terminal wideband impedance modeling module, an oscillation risk identification module, and a phase-locked loop collaborative control module.

[0054] The terminal wideband impedance modeling module is used to perform small-signal voltage disturbance injection under grid-connected steady state of the converter, collect positive and negative sequence voltage and current data, complete synchronous rotating coordinate transformation, obtain the frequency response data of positive and negative sequence impedance by obtaining complex ratio values, and construct the terminal wideband impedance model 100 based on the real and imaginary part parameters.

[0055] The oscillation risk identification module is used to combine the wideband impedance model 100 at the generator end with the equivalent impedance on the grid side to construct the impedance phase and amplitude matching criterion 200, analyze the impedance amplitude ratio and phase difference in real time, identify frequency points with amplitude ratio approaching 1 and phase difference approaching 180° as potential oscillation risk points, cluster the identified frequency points to form subsynchronous and supersynchronous risk frequency bands, and determine the dynamic influence interval 21 related to the phase-locked loop bandwidth.

[0056] The phase-locked loop (PLL) collaborative control module is used to adjust the PLL bandwidth and filtering parameters based on the identified risk frequency band 20 and dynamic influence interval 21, construct a leakage matrix describing the positive-sequence and negative-sequence coupling characteristics, perform matrix inversion compensation, and synchronously update the gain parameters of the d-axis and q-axis current control loops.

[0057] This embodiment also provides a computer device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements a personnel positioning safety management visualization analysis system as proposed in the above embodiment.

[0058] This embodiment also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements a personnel positioning safety management visualization analysis system as proposed in the above embodiment.

[0059] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part 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 is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0060] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-including system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0061] More specific examples of computer-readable media (a non-exhaustive list) include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0062] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0063] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for suppressing oscillation characteristics of wind power converters based on wideband impedance scanning, characterized in that, include: Based on the small-signal voltage disturbance injection in grid-connected steady state, the broadband response data of positive sequence impedance and negative sequence impedance are extracted respectively (10), and the broadband impedance model of the machine terminal is constructed (100). Based on the broadband impedance model, the impedance phase and amplitude matching criteria are constructed by combining the equivalent impedance of the power grid side (200), the risk frequency bands of subsynchronous and supersynchronous oscillations are identified (20), and the dynamic influence range related to the bandwidth of the phase-locked loop is determined (21). Based on the risk frequency band (20) and dynamic influence range (21), the phase-locked loop bandwidth and filtering parameters are adjusted, and the d / q control loop is coordinated and constrained in combination with the leakage matrix parameters (300).

2. The method for suppressing oscillation characteristics of wind power converters based on wideband impedance scanning as described in claim 1, characterized in that: The small-signal voltage perturbation injection includes, Under grid-connected steady state, positive-sequence disturbance signals and negative-sequence disturbance signals with controllable amplitudes are superimposed on the generator terminal voltage. The generator terminal current response before and after the disturbance is collected respectively. Synchronous rotating coordinate transformation is performed on the three-phase signal (11) to decompose the sampled signal into positive-sequence and negative-sequence components. The complex ratio value of each injection point is obtained to form the wideband response curves of positive-sequence impedance and negative-sequence impedance, which characterize the voltage and current coupling characteristics of the converter in the low-frequency, subsynchronous and supersynchronous frequency bands.

3. The method for suppressing oscillation characteristics of wind power converters based on wideband impedance scanning as described in claim 1 or 2, characterized in that: The terminal broadband impedance model (100) includes, A frequency response matrix is ​​established by interpolating and fitting positive-sequence impedance and negative-sequence impedance data in the frequency domain. During the modeling process, the real and imaginary impedance parameters are extracted and subjected to composite normalization, and the impedance features at each frequency point are continuously spliced ​​on the frequency axis.

4. The method for suppressing oscillation characteristics of wind power converters based on wideband impedance scanning as described in claim 3, characterized in that: The impedance phase and amplitude matching criterion (200) includes, A matching function is constructed based on the phase and amplitude relationship between the terminal broadband impedance model (100) and the grid-side equivalent impedance in the complex plane to obtain the phase difference and amplitude ratio in real time. When the amplitude ratio approaches 1 and the phase difference approaches 180°, the current frequency point is determined to be a potential oscillation risk point; Cluster analysis is performed on all risk points to form a continuous risk frequency band (20) interval, distinguishing risk areas belonging to subsynchronous frequency band and supersynchronous frequency band, and providing phase-locked loop parameter adjustment constraint boundary.

5. The method for suppressing the oscillation characteristics of wind power converters based on wideband impedance scanning as described in any one of claims 1, 2, and 4, characterized in that: The dynamic influence range (21) includes, Based on the phase response among phase-locked loop bandwidth, filter cutoff frequency, and sampling period, a mapping relationship between bandwidth adjustment and impedance phase change is established. When bandwidth adjustment causes the impedance phase margin to drop to a preset stable threshold, the frequency point corresponding to the current bandwidth is defined as being in the dynamic influence range (21). By analyzing the response of frequency points within the dynamic influence range (21), the adjustable bandwidth range and the allowable variation range of filter parameters are obtained.

6. The method for suppressing oscillation characteristics of wind power converters based on wideband impedance scanning as described in claim 5, characterized in that: The leakage matrix parameters (300) include, Construct a two-dimensional complex matrix to describe the coupling characteristics of positive-sequence and negative-sequence currents, and define the matrix elements to represent the ratio of positive-sequence current leakage to the negative-sequence channel and the ratio of negative-sequence current leakage to the positive-sequence channel, respectively; The matrix parameters are obtained by performing frequency response matrix analysis on the sampled signal at the machine end. When the amplitude of the cross term in the leakage matrix is ​​greater than the set leakage threshold, the linkage reconstruction of the phase-locked loop bandwidth and the filtering parameters is triggered. The leakage component is compensated and corrected by matrix inversion to reduce inter-sequence coupling error.

7. The method for suppressing the oscillation characteristics of wind power converters based on wideband impedance scanning as described in any one of claims 1, 2, 4, and 6, characterized in that: The coordinated constraints of the d / q control loop include: After the leakage matrix compensation and phase-locked loop bandwidth adjustment are completed, the gain parameters of the d-axis and q-axis current control loops are updated synchronously. The rotation angle of the d / q decoupling matrix and the current reference coordinates are calibrated in real time. The voltage and current are vector reconstructed in the synchronous rotating coordinate system so that the corrected positive-sequence impedance and negative-sequence impedance maintain symmetry in the frequency domain distribution.

8. A wind power converter oscillation characteristic suppression system based on wideband impedance scanning, employing the wind power converter oscillation characteristic suppression method based on wideband impedance scanning as described in any one of claims 1 to 7, characterized in that: Includes a wideband impedance modeling module for the machine terminal, an oscillation risk identification module, and a phase-locked loop collaborative control module; The terminal wideband impedance modeling module is used to perform small-signal voltage disturbance injection under grid-connected steady state of the converter, collect positive and negative sequence voltage and current data, complete synchronous rotating coordinate transformation, obtain complex ratio values ​​to obtain frequency response data of positive and negative sequence impedance, and construct a terminal wideband impedance model (100) based on real and imaginary part parameters. The oscillation risk identification module is used to combine the wideband impedance model (100) of the generator end with the equivalent impedance of the grid side to construct the impedance phase and amplitude matching criterion (200), analyze the impedance amplitude ratio and phase difference in real time, identify frequency points with amplitude ratio close to 1 and phase difference close to 180° as potential oscillation risk points, cluster the identified frequency points to form subsynchronous and supersynchronous risk frequency bands, and determine the dynamic influence range (21) related to the phase-locked loop bandwidth. The phase-locked loop collaborative control module is used to adjust the phase-locked loop bandwidth and filtering parameters based on the identified risk frequency band (20) and dynamic influence interval (21), construct a leakage matrix describing the positive and negative sequence coupling characteristics, perform matrix inversion compensation, and synchronously update the gain parameters of the d-axis and q-axis current control links.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the wind power converter oscillation characteristic suppression method based on wideband impedance scanning as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the wind power converter oscillation characteristic suppression method based on wideband impedance scanning as described in any one of claims 1 to 7.

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