Oscillation stability analysis method based on calculation of logarithmic derivative of aggregate impedance determinant

Abstract

The present application relates to the technical field of power system stability analysis, and in particular to an oscillation stability analysis method based on the calculation of the logarithmic derivative of the aggregate impedance determinant, the method comprising: calculating the aggregate impedance determinant of the power system; taking a derivative or difference of the aggregate impedance determinant to obtain the logarithmic derivative of the aggregate impedance determinant; obtaining the frequency of each extreme point based on the real extreme value of the logarithmic derivative, and analyzing the stability of the power system from the frequency of each extreme point to generate the stability analysis result of the power system. Thus, the problem of large amount of calculation or difficulty in accurately obtaining quantitative analysis results such as damping in the related technology is solved, and the oscillation stability can be accurately and quantitatively analyzed, and the conditions of easy modeling and low computational complexity are met.

Description

Technical Field

[0001] The present application relates to the technical field of power system stability analysis, and in particular to an oscillation stability analysis method based on the calculation of the logarithmic derivative of the aggregate impedance determinant. Background Art

[0002] With the massive access of power electronic equipment to the power grid, the problem of negatively damped electromagnetic oscillation caused by the interaction between power electronic equipment and the power grid has become increasingly prominent, seriously threatening the safe and stable operation of the power grid.

[0003] The oscillation stability analysis methods in related technologies mainly include the eigenvalue method and the impedance method.

[0004] However, although the eigenvalue method can accurately and quantitatively analyze the oscillation stability, it is difficult to model the "black-gray box" models that exist in large numbers in the system. In addition, in actual engineering, the number of power electronic equipment in the system is large and the topology is complex, resulting in a high dynamic order of the overall system and a huge amount of calculation. Although the impedance method is simple to calculate and easy to use, it can often only be used for qualitative stability judgment and it is difficult to accurately obtain quantitative analysis results such as damping.

[0005] Therefore, there is an urgent need for a method to solve the problems of large amount of calculation or difficulty in accurately obtaining quantitative analysis results such as damping in related technologies, which can accurately and quantitatively analyze oscillation stability and meet the conditions of easy modeling and low computational complexity.

[0006] Application Contents

[0007] The present application provides an oscillation stability analysis method based on the calculation of the logarithmic derivative of the aggregate impedance determinant to solve the problems of large amount of calculation or difficulty in accurately obtaining quantitative analysis results such as damping in related technologies. It can accurately and quantitatively analyze the oscillation stability and meet the conditions of easy modeling and low computational complexity.

[0008] The first aspect of the present application provides an oscillation stability analysis method based on the calculation of the logarithmic derivative of the aggregate impedance determinant, comprising the following steps:

[0009] Calculate the aggregate impedance determinant of the power system;

[0010] Derivative or differential the aggregate impedance determinant to obtain a logarithmic derivative of the aggregate impedance determinant;

[0011] Based on the real extreme value of the logarithmic derivative, the frequency of each extreme point is obtained, and the stability of the power system is analyzed by the frequencies of each extreme point to generate a stability analysis result of the power system.

[0012] Optionally, analyzing the stability of the power system by the extreme point frequencies to generate a stability analysis result of the power system includes:

[0013] Determine the imaginary and real parts of the zero point corresponding to the extreme point frequency;

[0014] The stability of the power system is determined based on the imaginary part and the real part of the zero point, and the oscillation damping and frequency are obtained.

[0015] Optionally, determining the stability of the power system based on the imaginary part and the real part of the zero point, and obtaining the oscillation damping and frequency, includes:

[0016] If the real part is greater than 0 and the imaginary part is not 0, the zero point corresponds to an unstable oscillation mode;

[0017] If the real parts of all zero points are less than 0, the power system is determined to be stable.

[0018] Optionally, calculating the aggregate impedance determinant of the power system includes:

[0019] Obtaining the aggregate impedance of the power system based on a preset frequency domain impedance model of each element in the power system;

[0020] A determinant of an aggregate impedance of the power system is calculated based on the aggregate impedance of the power system.

[0021] Optionally, the calculation formula of the logarithmic derivative is:

[0022]

[0023] Among them, Δ'(ω) is the derivative of the determinant Δ(ω), D L (Δ) is the logarithmic derivative of the determinant Δ(ω), ω is the frequency, and j is the imaginary unit.

[0024] The second aspect of the present application provides an oscillation stability analysis device based on the calculation of the logarithmic derivative of the aggregate impedance determinant, comprising:

[0025] A calculation module for calculating the aggregate impedance determinant of the power system;

[0026] An acquisition module, used for performing differentiation or differentiation on the aggregate impedance determinant to obtain a logarithmic derivative of the aggregate impedance determinant;

[0027] The analysis module is used to obtain the frequency of each extreme point based on the real extreme value of the logarithmic derivative, and analyze the stability of the power system based on the extreme point frequencies to generate a stability analysis result of the power system.

[0028] Optionally, the analysis module is specifically used to:

[0029] Determine the imaginary and real parts of the zero point corresponding to the extreme point frequency;

[0030] The stability of the power system is determined based on the imaginary part and the real part of the zero point, and the oscillation damping and frequency are obtained.

[0031] Optionally, the analysis module is specifically used to:

[0032] If the real part is greater than 0 and the imaginary part is not 0, the zero point corresponds to an unstable oscillation mode;

[0033] If the real parts of all zero points are less than 0, the power system is determined to be stable.

[0034] Optionally, the calculation module is specifically used to:

[0035] Obtaining the aggregate impedance of the power system based on a preset frequency domain impedance model of each element in the power system;

[0036] A determinant of an aggregate impedance of the power system is calculated based on the aggregate impedance of the power system.

[0037] Optionally, the calculation formula of the logarithmic derivative is:

[0038]

[0039] Among them, Δ'(ω) is the derivative of the determinant Δ(ω), D L (Δ) is the logarithmic derivative of the determinant Δ(ω), ω is the frequency, and j is the imaginary unit.

[0040] The third aspect of the present application provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the oscillation stability analysis method based on the calculation of the logarithmic derivative of the aggregate impedance determinant as described in the above embodiment.

[0041] The fourth aspect of the present application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the above-mentioned oscillation stability analysis method based on the calculation of the logarithmic derivative of the aggregate impedance determinant.

[0042] Therefore, the oscillation stability analysis method based on the calculation of the logarithmic derivative of the aggregate impedance determinant in the embodiment of the present application has the following advantages:

[0043] (1) The present application has high computational efficiency. The damping and frequency of each oscillation mode in a given frequency band can be obtained only by the real and imaginary part curves of the logarithmic derivative in the given frequency band, thus avoiding the extremely computationally intensive problem of solving the zero points of high-order polynomials.

[0044] (2) Since the present application is calculated based on the frequency domain impedance characteristics of the system, the frequency domain impedance of the "black-gray box" model can be obtained by injecting disturbances, that is, the present application is applicable to the "black-gray box" model scenario;

[0045] (3) The calculation accuracy of this application is high and it can be applied to larger-scale power systems. It has been verified in a single-machine grid-connected system of a voltage source converter and a large-scale wind power grid-connected system.

[0046] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0048] Figure 1 A flowchart of an oscillation stability analysis method based on the calculation of the logarithmic derivative of the aggregate impedance determinant provided according to an embodiment of the present application;

[0049] Figure 2 This is an example diagram of an oscillation stability analysis device based on the calculation of the logarithmic derivative of the aggregate impedance determinant according to an embodiment of the present application;

[0050] Figure 3 is an exemplary diagram of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0051] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0052] The following describes the oscillation stability analysis method based on the calculation of the logarithmic derivative of the aggregate impedance determinant of the embodiment of the present application with reference to the accompanying drawings. In view of the problem that the related technology mentioned in the above background technology has a large amount of calculation, or it is difficult to accurately obtain quantitative analysis results such as damping, the present application provides an oscillation stability analysis method based on the calculation of the logarithmic derivative of the aggregate impedance determinant. In this method, the aggregate impedance determinant of the power system is calculated, and the logarithmic derivative of the aggregate impedance determinant is calculated, and the real extreme value of the logarithmic derivative is solved, and all extreme points are identified one by one to determine whether they correspond to a zero point, and the zero point is solved, so as to judge the system oscillation stability by the real and imaginary parts of the zero point, and give the oscillation damping and frequency. As a result, the problem that the related technology has a large amount of calculation, or it is difficult to accurately obtain quantitative analysis results such as damping, can accurately and quantitatively analyze the oscillation stability, and meet the conditions of easy modeling and low computational complexity.

[0053] Specifically, Figure 1 A schematic flow chart of an oscillation stability analysis method based on the calculation of the logarithmic derivative of the aggregate impedance determinant provided in an embodiment of the present application.

[0054] like Figure 1 As shown, the oscillation stability analysis method based on the calculation of the logarithmic derivative of the aggregate impedance determinant includes the following steps:

[0055] In step S101 , the aggregate impedance determinant of the power system is calculated.

[0056] Optionally, in some embodiments, calculating the aggregate impedance determinant of the power system includes: obtaining the aggregate impedance of the power system based on a preset frequency domain impedance model of each element in the power system; and calculating the aggregate impedance determinant of the power system according to the aggregate impedance of the power system.

[0057] Specifically, the embodiment of the present application can first establish a frequency domain impedance model of each component in the power system, obtain the aggregate impedance through operations such as impedance series and parallel connection and node elimination, and then calculate the aggregate determinant Δ(ω) of the power system based on the aggregate impedance.

[0058] In step S102, the aggregate impedance determinant is differentiated or differentiated to obtain a logarithmic derivative of the aggregate impedance determinant.

[0059] It should be understood that the embodiment of the present application can calculate the logarithmic derivative D of the aggregate impedance determinant Δ(ω) by a derivation or differential method. L (Δ).

[0060] In some embodiments, the calculation formula of the logarithmic derivative is:

[0061]

[0062] Among them, Δ'(ω) is the derivative of the determinant Δ(ω), D L (Δ) is the logarithmic derivative of the determinant Δ(ω), ω is the frequency, and j is the imaginary unit.

[0063] In step S103, based on the extreme value of the real part of the logarithmic derivative, the frequency of each extreme point is obtained, and the stability of the power system is analyzed by the frequency of each extreme point to generate a stability analysis result of the power system.

[0064] Optionally, in some embodiments, the stability of the power system is analyzed by each extreme point frequency to generate a stability analysis result of the power system, including: determining the imaginary part and the real part of the zero point corresponding to the extreme point frequency; determining the stability of the power system based on the imaginary part and the real part of the zero point, and obtaining the oscillation damping and frequency.

[0065] Among them, in some embodiments, the stability of the power system is determined based on the imaginary part and the real part of the zero point, and the oscillation damping and frequency are obtained, including: if the real part is greater than 0 and the imaginary part is not 0, the zero point corresponds to an unstable oscillation mode; if the real part of each zero point is less than 0, the power system is determined to be stable.

[0066] Specifically, the embodiment of the present application can solve the extreme value of the real part of the logarithmic derivative to obtain the frequency ω of each extreme point i , and then identify all extreme points one by one. If the extreme point frequency ω i The corresponding imaginary slope of the logarithmic derivative is negative, then the extreme point corresponds to the zero point:

[0067] z i =α i +jω i ; (2)

[0068] Among them, the real part α i It can be solved by the following formula:

[0069]

[0070] If there is a zero point whose real part is greater than 0 and whose imaginary part is not 0, then the zero point corresponds to an unstable oscillation mode, and the real part corresponds to the divergence rate, and the imaginary part corresponds to the oscillation frequency; if the real parts of all the zero points obtained are less than 0, the power system is determined to be stable.

[0071] For example, the aggregate impedance determinant Δ(ω) is a first-order polynomial in the real frequency domain with only one zero α i +jω i :

[0072] Δ(ω)=a(jω-(α i +jω i )); (4)

[0073] Calculate the real and imaginary parts of its logarithmic derivative:

[0074]

[0075]

[0076] The real part of the logarithmic derivative has only one extreme point ω=ω i , and the slope of the imaginary part of the logarithmic derivative at the extreme point is negative (-1 / α i 2 ), then the extreme point corresponds to the zero point, and the real part of the zero point calculated by formula (3) is different from the actual real part of the zero point α i Exactly equal, the extreme point is also equal to the actual zero point imaginary part ω i This verifies that the zero point can be calculated from the logarithmic derivative, and then the stability can be judged based on the zero point. If α i Greater than 0 and ω i is not 0, then the zero point corresponds to an unstable oscillation mode. i If it is less than 0, the system is stable.

[0077] It should be noted that in the above steps S101 to S103, the embodiment of the present application can replace Δ(ω) in the logarithmic derivative method with other transfer functions converted to the real frequency domain to solve the zero point; it can also be based on the method of obtaining the zero point, by determining that the slope of the imaginary part of the logarithmic derivative is positive, removing the negative sign in equation (3), and changing it to a method of solving the pole, to implement the oscillation stability analysis method based on the calculation of the logarithmic derivative of the aggregate impedance determinant of the present application, without specific limitation here.

[0078] According to the oscillation stability analysis method based on the calculation of the logarithmic derivative of the aggregate impedance determinant proposed in the embodiment of the present application, the aggregate impedance determinant of the power system is calculated, and the logarithmic derivative of the aggregate impedance determinant is calculated, and the real extreme value of the logarithmic derivative is solved, and all extreme points are identified one by one to determine whether they correspond to a zero point, and the zero point is solved, so as to judge the system oscillation stability through the real and imaginary parts of the zero point, and give the oscillation damping and frequency. Thus, the problem of large amount of calculation or difficulty in accurately obtaining quantitative analysis results such as damping in the related technology is solved, and the oscillation stability can be accurately and quantitatively analyzed, and the conditions of easy modeling and low computational complexity are met.

[0079] Next, an oscillation stability analysis device based on the calculation of the logarithmic derivative of the aggregate impedance determinant proposed in accordance with an embodiment of the present application will be described with reference to the accompanying drawings.

[0080] Figure 2 It is a block diagram of an oscillation stability analysis device based on the calculation of the logarithmic derivative of the aggregate impedance determinant according to an embodiment of the present application.

[0081] like Figure 2As shown, the oscillation stability analysis device 10 based on the calculation of the logarithmic derivative of the aggregate impedance determinant includes: a calculation module 100 , an acquisition module 200 and an analysis module 300 .

[0082] Wherein, the calculation module 100 is used to calculate the aggregate impedance determinant of the power system;

[0083] The acquisition module 200 is used to derive or differentiate the aggregate impedance determinant to obtain the logarithmic derivative of the aggregate impedance determinant;

[0084] The analysis module 300 is used to obtain the frequency of each extreme point based on the real extreme value of the logarithmic derivative, and analyze the stability of the power system according to the frequency of each extreme point to generate a stability analysis result of the power system.

[0085] Optionally, the analysis module 300 is specifically used for:

[0086] Determine the imaginary and real parts of the zero point corresponding to the extreme point frequency;

[0087] The stability of the power system is determined based on the imaginary and real parts of the zero point, and the oscillation damping and frequency are obtained.

[0088] Optionally, the analysis module 300 is specifically used for:

[0089] If the real part is greater than 0 and the imaginary part is not 0, the zero point corresponds to an unstable oscillation mode;

[0090] If the real parts of all zeros are less than 0, the power system is considered stable.

[0091] Optionally, the calculation module 200 is specifically used for:

[0092] Obtaining the aggregate impedance of the power system based on a preset frequency domain impedance model of each component in the power system;

[0093] The aggregate impedance determinant of the power system is calculated based on the aggregate impedance of the power system.

[0094] Optionally, the logarithmic derivative is calculated as:

[0095]

[0096] Among them, Δ'(ω) is the derivative of the determinant Δ(ω), D L (Δ) is the logarithmic derivative of the determinant Δ(ω), ω is the frequency, and j is the imaginary unit.

[0097] It should be noted that the aforementioned explanation of the embodiment of the oscillation stability analysis method based on the calculation of the logarithmic derivative of the aggregate impedance determinant is also applicable to the oscillation stability analysis device based on the calculation of the logarithmic derivative of the aggregate impedance determinant of this embodiment, and will not be repeated here.

[0098] According to the oscillation stability analysis device based on the calculation of the logarithmic derivative of the aggregate impedance determinant proposed in the embodiment of the present application, the aggregate impedance determinant of the power system is calculated, and the logarithmic derivative of the aggregate impedance determinant is calculated, and the real extreme value of the logarithmic derivative is solved, and all extreme points are identified one by one to determine whether they correspond to a zero point, and the zero point is solved, so as to determine the system oscillation stability through the real and imaginary parts of the zero point, and give the oscillation damping and frequency. Thus, the problem of large amount of calculation or difficulty in accurately obtaining quantitative analysis results such as damping in the related art is solved, and the oscillation stability can be accurately and quantitatively analyzed, and the conditions of easy modeling and low computational complexity are met.

[0099] Figure 3 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device may include:

[0100] A memory 301 , a processor 302 , and a computer program stored in the memory 301 and executable on the processor 302 .

[0101] When the processor 302 executes the program, the oscillation stability analysis method based on the calculation of the logarithmic derivative of the aggregate impedance determinant provided in the above embodiment is implemented.

[0102] Furthermore, the electronic device further comprises:

[0103] The communication interface 303 is used for communication between the memory 301 and the processor 302 .

[0104] The memory 301 is used to store computer programs that can be run on the processor 302 .

[0105] The memory 301 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0106] If the memory 301, the processor 302 and the communication interface 303 are implemented independently, the communication interface 303, the memory 301 and the processor 302 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 3Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0107] Optionally, in a specific implementation, if the memory 301, the processor 302 and the communication interface 303 are integrated on a chip, the memory 301, the processor 302 and the communication interface 303 can communicate with each other through an internal interface.

[0108] The processor 302 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0109] This embodiment also provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the oscillation stability analysis method based on the calculation of the logarithmic derivative of the aggregate impedance determinant is implemented as described above.

[0110] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0111] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0112] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0113] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or N wirings (electronic devices), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0114] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0115] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0116] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0117] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. An oscillation stability analysis method based on the calculation of the logarithmic derivative of the polymer impedance determinant, characterized in that: The following steps are involved: Calculate the aggregate impedance determinant of the power system; The aggregate impedance determinant is differentiated or differentiated to obtain a logarithmic derivative of the aggregate impedance determinant, wherein the calculation formula of the logarithmic derivative is: Among them, Δ'(ω) is the derivative of the determinant Δ(ω), D L (Δ) is the logarithmic derivative of the determinant Δ(ω), ω is the frequency, and j is the imaginary unit; Based on the real extreme value of the logarithmic derivative, the frequency of each extreme point is obtained, and the stability of the power system is analyzed by the frequencies of each extreme point to generate a stability analysis result of the power system; The step of analyzing the stability of the power system by the extreme point frequencies to generate the stability analysis result of the power system includes: determining the imaginary part and the real part of the zero point corresponding to the extreme point frequency; determining the stability of the power system based on the imaginary part and the real part of the zero point, and obtaining the oscillation damping and frequency; The determining the stability of the power system based on the imaginary part and the real part of the zero point, and obtaining the oscillation damping and frequency, comprises: if the real part is greater than 0 and the imaginary part is not 0, the zero point corresponds to an unstable oscillation mode; if the real parts of all zero points are less than 0, the power system is determined to be stable; Among them, the frequency of each extreme point ω i The real part of the logarithmic derivative is solved and then all extreme points are identified one by one. If the extreme point frequency ω i The corresponding imaginary slope of the logarithmic derivative is negative, then the extreme point corresponds to the zero point: z i =α i +jω i ; Among them, the real part α i It can be solved by the following formula: Among them, D L (Δ) is the logarithmic derivative of the polymer impedance determinant.

2. The method according to claim 1, characterized in that The method of calculating the aggregate impedance determinant of the power system comprises: Obtaining the aggregate impedance of the power system based on a preset frequency domain impedance model of each element in the power system; A determinant of an aggregate impedance of the power system is calculated based on the aggregate impedance of the power system.

3. An oscillation stability analysis device based on the calculation of the logarithmic derivative of the polymer impedance determinant, characterized in that: include: A calculation module for calculating the aggregate impedance determinant of the power system; An acquisition module is used to derive or differentiate the aggregate impedance determinant to obtain a logarithmic derivative of the aggregate impedance determinant, wherein the calculation formula of the logarithmic derivative is: Among them, Δ'(ω) is the derivative of the determinant Δ(ω), D L (Δ) is the logarithmic derivative of the determinant Δ(ω), ω is the frequency, and j is the imaginary unit; An analysis module, configured to obtain the frequency of each extreme point based on the real extreme value of the logarithmic derivative, and analyze the stability of the power system according to the frequency of each extreme point to generate a stability analysis result of the power system; The analysis module is specifically used to: determine the imaginary part and the real part of the zero point corresponding to the extreme point frequency; determine the stability of the power system based on the imaginary part and the real part of the zero point, and obtain the oscillation damping and frequency; The analysis module is specifically used to: if the real part is greater than 0 and the imaginary part is not 0, the zero point corresponds to an unstable oscillation mode; if the real parts of all zero points are less than 0, it is determined that the power system is stable; Among them, the frequency of each extreme point ω i The real part of the logarithmic derivative is solved and then all extreme points are identified one by one. If the extreme point frequency ω i The corresponding imaginary slope of the logarithmic derivative is negative, then the extreme point corresponds to the zero point: z i =α i +jω i ; Among them, the real part α i It can be solved by the following formula: Among them, D L (Δ) is the logarithmic derivative of the polymer impedance determinant.

4. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the oscillation stability analysis method based on the calculation of the logarithmic derivative of the aggregate impedance determinant as described in any one of claims 1 to 2.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the oscillation stability analysis method based on the calculation of the logarithmic derivative of the aggregate impedance determinant as described in any one of claims 1 to 2.

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