Graded early warning method and system for oscillation risk of new energy access system

Abstract

The invention discloses a graded early warning method and system for oscillation risks of a new energy access system, and belongs to the technical field of new energy access and control. The method comprises the following steps: acquiring system information of a new energy access system, and initializing to obtain parameter information of the new energy system under different working conditions according to the system information; based on the parameter information, determining a network source impedance ratio curve, a risk area and a prohibited area of the new energy access system in different frequency bands under a Newton plane; and determining whether the network source impedance ratio curves of different frequency bands under the Nyquist plane enter a risk area in the Nyquist plane, if yes, judging whether the network source impedance ratio curves enter a prohibited area, if yes, sending out advanced early warning of oscillation risks, and if not, sending out intermediate early warning of the oscillation risks. By dividing the risk area and the prohibited area and judging whether the curve enters the risk area and the prohibited area, graded early warning can be performed, and calculation is simple and efficient.

Description

Technical Field

[0001] The present invention relates to the field of new energy access and control technology, and more specifically, to a hierarchical early warning method and system for oscillation risk of a new energy access system. Background Art

[0002] my country's new energy is mostly developed on a large scale and transmitted over long distances. Large new energy bases are mostly far away from the main grid, resulting in a high proportion of new energy connected to weak grids in some local areas. New energy / energy storage equipment is directly or indirectly connected to the grid through power electronic equipment, which has the characteristics of low inertia and weak synchronous support. In addition, the control structure of power electronic equipment is complex, and the grid-connected characteristics vary significantly in the broadband, which leads to increased stability risks of large-scale new energy grid-connected systems. How to effectively warn of the broadband oscillation risk of new energy access systems is an urgent problem to be solved. Summary of the invention

[0003] In view of the above problems, the present invention proposes a hierarchical early warning method for oscillation risk of a new energy access system, comprising:

[0004] Acquire system information of a new energy access system, and initialize and obtain parameter information of the new energy system under different working conditions according to the system information;

[0005] Based on the parameter information, determining the network source impedance ratio curve, risk area and prohibited area of ​​the new energy access system in different frequency bands under the Nyx plane;

[0006] Determine whether the network source impedance ratio curves of different frequency bands under the Nyquist plane enter the risk area in the Nyquist plane. If so, determine whether it enters the prohibited area. If so, issue a high-level warning of oscillation risk, otherwise issue a medium-level warning of oscillation risk.

[0007] Optional, system information, including: machine model, capacity and collector line topology.

[0008] Optional, parameter information, including:

[0009] The unit's broadband impedance, frequency band division parameters, prohibited area radius of frequency band setting, resonance warning strategy threshold and collector network line parameters.

[0010] Optionally, based on the parameter information, determining a network source impedance ratio curve of the new energy access system in different frequency bands under the Nyx plane includes:

[0011] According to the unit broadband impedance, frequency band division parameters and collection network line parameters in the parameter information, the source side broadband impedance of the new energy access system is calculated, and according to the source side broadband impedance and the pre-measured grid side broadband impedance, the grid-source impedance ratio of different frequency bands in the Nyquist plane is calculated, and a grid-source impedance ratio curve is drawn according to the grid-source impedance ratio.

[0012] Optionally, based on the parameter information, determining risk areas and prohibited areas of the new energy access system in different frequency bands under the Nyx plane includes:

[0013] According to the prohibited area radius and resonance warning strategy threshold of the sub-band setting in the parameter information, the risk areas of the new energy access system in different frequency bands under the Nyquist plane are calculated, and the prohibited area is determined according to the risk area and the maximum peak Nyquist stability criterion.

[0014] Optionally, the risk area is a circular area with a radius of K*R min ;

[0015] Among them, Rmin is the forbidden area radius of the frequency division band setting, and K is the resonance warning strategy threshold;

[0016] Among them, 1 <K<2。

[0017] Optionally, determining whether the network source impedance ratio curves of different frequency bands under the Nyx plane enter the risk area in the Nyx plane includes:

[0018] Determine whether the distance between the network source impedance ratio curve and the Nyquist plane (-1, j0) point is less than or equal to K*R min , if so, it enters the risk area in the Nyquist plane.

[0019] On the other hand, the present invention also proposes a hierarchical early warning system for oscillation risk of a new energy access system, comprising:

[0020] A data acquisition unit, used to obtain system information of the new energy access system, and initialize parameter information of the new energy system under different working conditions according to the system information;

[0021] A calculation unit, configured to determine, based on the parameter information, a network source impedance ratio curve, a risk area, and a prohibited area of ​​the new energy access system in different frequency bands under the Nyx plane;

[0022] The early warning unit is used to determine whether the network source impedance ratio curves of different frequency bands under the Nyquist plane enter the risk area in the Nyquist plane. If so, it is judged whether it enters the prohibited area. If so, a high-level early warning of oscillation risk is issued, otherwise a medium-level early warning of oscillation risk is issued.

[0023] Optional, system information, including: machine model, capacity and collector line topology.

[0024] Optional, parameter information, including:

[0025] The unit's broadband impedance, frequency band division parameters, prohibited area radius of frequency band setting, resonance warning strategy threshold and collector network line parameters.

[0026] Optionally, the calculation unit determines, based on the parameter information, a network source impedance ratio curve of the new energy access system in different frequency bands in the Nyx plane, including:

[0027] According to the unit broadband impedance, frequency band division parameters and collection network line parameters in the parameter information, the source side broadband impedance of the new energy access system is calculated, and according to the source side broadband impedance and the pre-measured grid side broadband impedance, the grid-source impedance ratio of different frequency bands in the Nyquist plane is calculated, and a grid-source impedance ratio curve is drawn according to the grid-source impedance ratio.

[0028] Optionally, the calculation unit determines, based on the parameter information, risk areas and prohibited areas of the new energy access system in different frequency bands under the Nyx plane, including:

[0029] According to the prohibited area radius and resonance warning strategy threshold of the sub-band setting in the parameter information, the risk areas of the new energy access system in different frequency bands under the Nyquist plane are calculated, and the prohibited area is determined according to the risk area and the maximum peak Nyquist stability criterion.

[0030] Optionally, the risk area is a circular area with a radius of K*R min ;

[0031] Among them, Rmin is the forbidden area radius of the frequency division band setting, and K is the resonance warning strategy threshold;

[0032] Among them, 1 <K<2。

[0033] Optionally, determining whether the network source impedance ratio curves of different frequency bands under the Nyx plane enter the risk area in the Nyx plane includes:

[0034] Determine whether the distance between the network source impedance ratio curve and the Nyquist plane (-1, j0) is less than or equal to K*R min , if so, it enters the risk area in the Nyquist plane.

[0035] In yet another aspect, the present invention further provides a computing device, comprising: one or more processors;

[0036] a processor for executing one or more programs;

[0037] When the one or more programs are executed by the one or more processors, the above-described method is implemented.

[0038] In yet another aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed, the method described above is implemented.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] The present invention provides a hierarchical early warning method for oscillation risk of new energy access system, including: obtaining system information of new energy access system, initializing parameter information of the new energy system under different working conditions according to the system information; determining the network source impedance ratio curve, risk area and prohibited area of ​​the new energy access system in different frequency bands under the Nyx plane based on the parameter information; determining whether the network source impedance ratio curve of different frequency bands under the Nyx plane enters the risk area in the Nyx plane, if so, judging whether it enters the prohibited area, if so, issuing a high-level early warning of oscillation risk, otherwise issuing a medium-level early warning of oscillation risk. The present invention can perform hierarchical early warning by dividing the risk area and the prohibited area, and judging whether the curve enters the risk area and the prohibited area, and the calculation is simple and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a flow chart of the method of the present invention;

[0042] Figure 2 is a flow chart of an embodiment of the method of the present invention;

[0043] Figure 3 The Thevenin equivalent circuit diagram in the embodiment of the method of the present invention;

[0044] Figure 4 A schematic diagram of a prohibited area and a risk area in a complex plane in an embodiment of the method of the present invention;

[0045] Figure 5 It is a structural diagram of the system of the present invention. DETAILED DESCRIPTION

[0046] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0047] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0048] Embodiment 1:

[0049] The present invention proposes a hierarchical early warning method for the oscillation risk of a new energy access system, such as Figure 1 As shown, including:

[0050] Step 1: Obtain system information of a new energy access system, and initialize and obtain parameter information of the new energy system under different working conditions according to the system information;

[0051] Step 2: Based on the parameter information, determine the network source impedance ratio curve, risk area and prohibited area of ​​the new energy access system in different frequency bands under the Nyx plane;

[0052] Step 3: Determine whether the network source impedance ratio curves of different frequency bands under the Nyx plane enter the risk area in the Nyx plane. If so, determine whether it enters the prohibited area. If so, issue a high-level warning of oscillation risk; otherwise, issue a medium-level warning of oscillation risk.

[0053] Among them, system information includes: model, capacity and collection line topology.

[0054] The parameter information includes:

[0055] The unit's broadband impedance, frequency band division parameters, prohibited area radius of frequency band setting, resonance warning strategy threshold and collector network line parameters.

[0056] Wherein, based on the parameter information, determining the network source impedance ratio curve of the new energy access system in different frequency bands under the Nyx plane includes:

[0057] According to the unit broadband impedance, frequency band division parameters and collection network line parameters in the parameter information, the source side broadband impedance of the new energy access system is calculated, and according to the source side broadband impedance and the pre-measured grid side broadband impedance, the grid-source impedance ratio of different frequency bands in the Nyquist plane is calculated, and a grid-source impedance ratio curve is drawn according to the grid-source impedance ratio.

[0058] Wherein, based on the parameter information, determining the risk area and prohibited area of ​​the new energy access system in different frequency bands under the Nyx plane includes:

[0059] According to the prohibited area radius and resonance warning strategy threshold of the sub-band setting in the parameter information, the risk areas of the new energy access system in different frequency bands under the Nyquist plane are calculated, and the prohibited area is determined according to the risk area and the maximum peak Nyquist stability criterion.

[0060] Among them, the risk area is a circular area with a radius of K*R min ;

[0061] Among them, Rmin is the forbidden area radius of the frequency division band setting, and K is the resonance warning strategy threshold;

[0062] Among them, 1 <K<2。

[0063] Among them, determining whether the network source impedance ratio curves of different frequency bands under the Nyx plane enter the risk area within the Nyx plane includes:

[0064] Determine whether the distance between the network source impedance ratio curve and the Nyquist plane (-1, j0) is less than or equal to K*R min , if so, it enters the risk area in the Nyquist plane.

[0065] The present invention is further described below in conjunction with specific implementation cases:

[0066] Example steps Figure 2 As shown, including:

[0067] Step 1: According to the information such as machine type, capacity, and collection line topology collected by the new energy station, initialize the unit broadband impedance, frequency band division parameters, frequency band setting prohibited area radius Rmin, threshold K, and collection network line parameters under different working conditions.

[0068] Referring to the industry standard NB / T 10651-2021 Technical Specification for Wind Farm Impedance Characteristics Evaluation, the frequency bands can be divided as shown in Table 1 below.

[0069] Table 1

[0070]

[0071] Step 2: Calculate the broadband impedance on the source side and the broadband impedance on the grid side respectively.

[0072] The broadband impedance of the grid side can be measured by the signal injection method, or the fundamental impedance of the grid side can be identified online using the measurement information of the grid connection point of the new energy station, and then according to the Thevenin equivalence principle, such as Figure 3 As shown, the broadband impedance on the grid side is calculated.

[0073] The specific steps are as follows:

[0074] (1) As shown in the figure, the Thevenin equivalent circuit, assuming that the Thevenin equivalent electromotive force E on the grid side g And the equivalent impedance Z g If there is no change during the time period of parameter identification, based on the measured data (I1, U1) and (I2, U2) of the grid connection point at different times, and based on Kirchhoff's law, the equivalent impedance on the grid side can be expressed as:

[0075]

[0076] (2) Based on the measurement data of the grid connection point at n different times (I1, U1)…(I n ,U n ), the equivalent impedance on the grid side can be estimated using the least squares method Then the following equation holds.

[0077]

[0078] in,

[0079] (3) The grid-side impedance estimated based on the above formula is the equivalent impedance under the fundamental wave (50Hz). n ,U n ) is in phasor form, the estimated grid-side basic impedance The same is in phasor form, rewriting it into complex form is:

[0080]

[0081] Based on the Thevenin equivalence theorem, the broadband impedance on the grid side can be calculated by the following formula:

[0082]

[0083] Among them, f b =50.

[0084] Step 3: Calculate the network source impedance ratio in different frequency bands based on the estimated value of the network source broadband impedance:

[0085]

[0086] in is the estimated value of broadband impedance on the source side.

[0087] Step 4: According to R min and K determine the risk area and forbidden area in the complex plane under different frequency bands and introduce the maximum peak Nyquist stability criterion, such as Figure 4 As shown in the figure, the system amplitude margin and phase margin requirements are represented as a point centered at (-1, j0) and R minA circular prohibited working area with a radius of; meanwhile, to better achieve the hierarchical early warning of broadband oscillation risks, on the basis of setting R min , a threshold K is set in the resonance early warning strategy, where 1 < K < 2. With the point (-1, j0) as the center and K*R min as the radius, a risk area is set, that is, Figure 4 the area enclosed by the dotted line in

[0088] Step 5: Judge whether the network source impedance ratio curve enters the risk area in different frequency bands under the Nyquist plane. Specifically, it can be determined by calculating whether the distance between the impedance ratio curve in the I, II, and III frequency bands and the point (-1, j0) is less than or equal to K*R min . If the network source impedance ratio curve enters the risk area in any frequency band, go to Step 6); otherwise, there is no oscillation risk in the new energy access system, and jump to Step 2).

[0089] Step 6: Use the same method to judge whether the network source impedance ratio curves in the I, II, and III frequency bands enter the prohibited area. If they enter the prohibited area, issue a high-risk warning of oscillation, and determine the high-risk mode range according to the intersection points of the network source impedance ratio curve and the boundary of the prohibited area; if they do not enter the prohibited area, issue a medium-risk warning of oscillation, and determine the medium-risk mode range according to the intersection points of the network source impedance ratio curve and the boundary of the risk area. Jump to Step 2) to perform the stable risk early warning for the next cycle.

[0090] Embodiment 2:

[0091] The present invention also proposes a hierarchical early warning system 200 for the oscillation risk of a new energy access system, as Figure 5 shown, including:

[0092] A data acquisition unit 201, configured to obtain the system information of the new energy access system, and initialize the parameter information of the new energy system under different working conditions according to the system information;

[0093] A calculation unit 202, configured to determine the network source impedance ratio curves, risk areas, and prohibited areas in different frequency bands of the new energy access system under the Nyquist plane based on the parameter information;

[0094] An early warning unit 203, configured to determine whether the network source impedance ratio curves in different frequency bands under the Nyquist plane enter the risk area in the Nyquist plane. If they enter, judge whether they enter the prohibited area. If so, issue a high-level warning of oscillation risk, otherwise issue a medium-level warning of oscillation risk.

[0095] Among them, the system information includes: model, capacity, and collector line topology.

[0096] Among them, the parameter information includes:

[0097] The unit's broadband impedance, frequency band division parameters, prohibited area radius of frequency band setting, resonance warning strategy threshold and collector network line parameters.

[0098] The calculation unit 202 determines, based on the parameter information, a network source impedance ratio curve of the new energy access system in different frequency bands under the Nyx plane, including:

[0099] According to the unit broadband impedance, frequency band division parameters and collection network line parameters in the parameter information, the source side broadband impedance of the new energy access system is calculated, and according to the source side broadband impedance and the pre-measured grid side broadband impedance, the grid-source impedance ratio of different frequency bands in the Nyquist plane is calculated, and a grid-source impedance ratio curve is drawn according to the grid-source impedance ratio.

[0100] The calculation unit 202 determines, based on the parameter information, risk areas and prohibited areas of the new energy access system in different frequency bands under the Nyx plane, including:

[0101] According to the prohibited area radius and resonance warning strategy threshold of the sub-band setting in the parameter information, the risk areas of the new energy access system in different frequency bands under the Nyquist plane are calculated, and the prohibited area is determined according to the risk area and the maximum peak Nyquist stability criterion.

[0102] Among them, the risk area is a circular area with a radius of K*R min ;

[0103] Among them, Rmin is the forbidden area radius of the frequency division band setting, and K is the resonance warning strategy threshold;

[0104] Among them, 1 <K<2。

[0105] Among them, determining whether the network source impedance ratio curves of different frequency bands under the Nyx plane enter the risk area within the Nyx plane includes:

[0106] Determine whether the distance between the network source impedance ratio curve and the Nyquist plane (-1, j0) point is less than or equal to K*R min , if so, it enters the risk area in the Nyquist plane.

[0107] The present invention can perform graded warning by dividing the risk area and the prohibited area and judging whether the curve enters the risk area and the prohibited area, and the calculation is simple and efficient.

[0108] Embodiment 3:

[0109] Based on the same inventive concept, the present invention also provides a computer device, which includes a processor and a memory, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding functions, so as to implement the steps of the method in the above embodiment.

[0110] Embodiment 4:

[0111] Based on the same inventive concept, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium here can include both a built-in storage medium in a computer device and an extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the method in the above embodiment.

[0112] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present invention may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0113] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0114] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0115] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0116] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0117] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A hierarchical early warning method for oscillation risk of new energy access system, characterized in that: include: Acquire system information of a new energy access system, and initialize and obtain parameter information of the new energy system under different working conditions according to the system information; Based on the parameter information, determining the network source impedance ratio curve, risk area and prohibited area of ​​the new energy access system in different frequency bands under the Nyx plane; Determine whether the network source impedance ratio curves of different frequency bands under the Nyquist plane enter the risk area in the Nyquist plane. If so, determine whether it enters the prohibited area. If so, issue a high-level warning of oscillation risk, otherwise issue a medium-level warning of oscillation risk.

2. The hierarchical warning method according to claim 1, characterized in that: The system information includes: machine model, capacity and collection line topology.

3. The hierarchical warning method according to claim 1, characterized in that: The parameter information includes: The unit's broadband impedance, frequency band division parameters, prohibited area radius of frequency band setting, resonance warning strategy threshold and collector network line parameters.

4. The hierarchical warning method according to claim 1, characterized in that: Based on the parameter information, determining the network source impedance ratio curve of the new energy access system in different frequency bands under the Nyx plane, including: According to the unit broadband impedance, frequency band division parameters and collection network line parameters in the parameter information, the source side broadband impedance of the new energy access system is calculated, and according to the source side broadband impedance and the pre-measured grid side broadband impedance, the grid-source impedance ratio of different frequency bands in the Nyquist plane is calculated, and a grid-source impedance ratio curve is drawn according to the grid-source impedance ratio.

5. The hierarchical warning method according to claim 1, characterized in that: Based on the parameter information, risk areas and prohibited areas of the new energy access system in different frequency bands under the Nyx plane are determined, including: According to the prohibited area radius and resonance warning strategy threshold of the sub-band setting in the parameter information, the risk areas of the new energy access system in different frequency bands under the Nyquist plane are calculated, and the prohibited area is determined according to the risk area and the maximum peak Nyquist stability criterion.

6. The method according to claim 5, characterized in that The risk area is a circular area with a radius of K*R min ; Among them, Rmin is the forbidden area radius of the frequency division band setting, and K is the resonance warning strategy threshold; Among them, 1 <K<2。 7. The method according to claim 1, characterized in that The determining whether the network source impedance ratio curves of different frequency bands under the Nyx plane enter the risk area in the Nyx plane includes: Determine whether the distance between the network source impedance ratio curve and the Nyquist plane (-1, j0) point is less than or equal to K*R min , if so, it enters the risk area in the Nyquist plane.

8. A hierarchical early warning system for oscillation risk of new energy access system, characterized in that: include: A data acquisition unit, used to obtain system information of the new energy access system, and initialize parameter information of the new energy system under different working conditions according to the system information; A calculation unit, configured to determine, based on the parameter information, a network source impedance ratio curve, a risk area, and a prohibited area of ​​the new energy access system in different frequency bands under the Nyx plane; The early warning unit is used to determine whether the network source impedance ratio curves of different frequency bands under the Nyquist plane enter the risk area in the Nyquist plane. If so, it is judged whether it enters the prohibited area. If so, a high-level early warning of oscillation risk is issued, otherwise a medium-level early warning of oscillation risk is issued.

9. The hierarchical warning system according to claim 8, characterized in that: The system information includes: machine model, capacity and collection line topology.

10. The hierarchical warning system according to claim 8, characterized in that: The parameter information includes: The unit's broadband impedance, frequency band division parameters, prohibited area radius of frequency band setting, resonance warning strategy threshold and collector network line parameters.

11. The hierarchical warning system according to claim 8, characterized in that: The calculation unit determines, based on the parameter information, a network source impedance ratio curve of the new energy access system in different frequency bands under the Nyx plane, including: According to the unit broadband impedance, frequency band division parameters and collection network line parameters in the parameter information, the source side broadband impedance of the new energy access system is calculated, and according to the source side broadband impedance and the pre-measured grid side broadband impedance, the grid-source impedance ratio of different frequency bands in the Nyquist plane is calculated, and a grid-source impedance ratio curve is drawn according to the grid-source impedance ratio.

12. The hierarchical warning system according to claim 8, characterized in that: The calculation unit determines, based on the parameter information, risk areas and prohibited areas of the new energy access system in different frequency bands under the Nyx plane, including: According to the prohibited area radius and resonance warning strategy threshold of the sub-band setting in the parameter information, the risk areas of the new energy access system in different frequency bands under the Nyquist plane are calculated, and the prohibited area is determined according to the risk area and the maximum peak Nyquist stability criterion.

13. The system according to claim 12, characterized in that The risk area is a circular area with a radius of K*R min ; Among them, Rmin is the forbidden area radius of the frequency division band setting, and K is the resonance warning strategy threshold; Among them, 1 <K<2。 14. The system according to claim 8, characterized in that The determining whether the network source impedance ratio curves of different frequency bands under the Nyx plane enter the risk area in the Nyx plane includes: Determine whether the distance between the network source impedance ratio curve and the Nyquist plane (-1, j0) point is less than or equal to K*R min , if so, it enters the risk area in the Nyquist plane.

15. A computer device, characterized in that: include: one or more processors; a processor for executing one or more programs; When the one or more programs are executed by the one or more processors, the method according to any one of claims 1 to 7 is implemented.

16. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed, the method according to any one of claims 1 to 7 is implemented.

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