Power system wide frequency oscillation damping monitoring method, device and equipment and storage medium
By monitoring speed-like and power-like variable signals at the generator unit port, and using Fourier transform and iterative adjustment, a time-domain estimation expression for the real part of the eigenvalues is constructed, solving the monitoring problem of broadband oscillations in new power systems and achieving efficient and accurate damping monitoring.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-08-15
- Publication Date
- 2026-03-17
AI Technical Summary
Existing energy flow methods are mainly used to monitor low-frequency oscillations in traditional power systems, but they are difficult to effectively monitor broadband oscillations in new power systems, which are mainly composed of new energy sources and power electronic converters.
By monitoring speed-like and power-like variable signals at the generator unit port, and using Fourier transform and iterative adjustment, a time-domain estimation expression for the real part of the eigenvalues is constructed to capture the damping information of broadband oscillations, thus avoiding high-dimensional modeling of the entire system.
It enables accurate monitoring of broadband oscillation damping in new power systems, improving the feasibility and accuracy of monitoring, and is applicable to power systems containing a large number of new energy sources and power electronic devices.
Smart Images
Figure CN115453231B_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of power system monitoring, and in particular relates to a method, device, equipment and computer-readable storage medium for monitoring broadband oscillation damping in power systems. Background Technology
[0002] The energy flow method, also known as the oscillation energy flow method, is a highly efficient method for monitoring and analyzing various power oscillations in power systems. Its working principle is based on the monitored attenuation rate of the oscillation energy flow, effectively reflecting the damping information of power oscillations in the system, thereby assisting power system operators in conducting system oscillation stability analysis and operational safety decisions. The energy flow method is an analytical method, and its data acquisition and input device is a phasor measurement unit (PMU).
[0003] Current energy flow methods are mainly used to monitor and analyze low-frequency oscillations in traditional power systems dominated by conventional synchronous generators. For emerging broadband oscillation problems in new power systems dominated by renewable energy sources and power electronic converters, there is an urgent need to expand the current energy flow method analysis theory. Summary of the Invention
[0004] This application provides a method, apparatus, device, and computer-readable storage medium for monitoring broadband oscillation damping in power systems, which can enable monitoring of various types of broadband oscillations at the power generation unit port.
[0005] In a first aspect, embodiments of this application provide a method for monitoring broadband oscillation damping in a power system, including:
[0006] In the dominant oscillation mode involved in the control loop of the measured power generation unit with two consecutive integral elements, the time-domain estimation expression of the real part of the characteristic value of the measured power generation unit is obtained.
[0007] Within a preset time period, the speed-like variable signal and power-like variable signal of the control loop of the measured power generation unit are collected;
[0008] Perform a Fourier transform on the speed variable signal, and obtain the angular frequency of the dominant oscillation mode involved in the control loop from the amplitude-frequency characteristic image obtained by the transform;
[0009] Select a dominant oscillation mode of interest, substitute the angular frequency, the speed-like variable signal, and the power-like variable signal into the time-domain estimation expression of the real part of the eigenvalue, and calculate the final estimated value of the real part of the eigenvalue of the dominant oscillation mode of interest through iterative adjustment.
[0010] Secondly, embodiments of this application provide a power system broadband oscillation damping monitoring device, comprising:
[0011] The expression acquisition unit is used to acquire the time-domain estimation expression of the real part of the eigenvalues of the measured power generation unit under the dominant oscillation mode involving the control loop of the measured power generation unit with two consecutive integral elements.
[0012] The phasor measurement unit is used to collect speed-like variable signals and power-like variable signals of the control loop of the measured power generation unit within a preset time period.
[0013] The signal transformation unit is used to perform Fourier transform on the speed variable signal and obtain the angular frequency of the dominant oscillation mode involved in the control loop from the amplitude-frequency characteristic image obtained by the transformation.
[0014] The computation unit is used to substitute the angular frequency, the speed-like variable signal, and the power-like variable signal into the time-domain estimation expression of the real part of the eigenvalues in a selected dominant oscillation mode of interest, and to calculate the final estimated value of the real part of the eigenvalues of the dominant oscillation mode of interest through iterative adjustment.
[0015] Thirdly, embodiments of this application provide a power system broadband oscillation damping monitoring device, the damping monitoring device including the damping monitoring device described in any of the second aspects, the damping monitoring device being disposed at the power generation unit port, such that the damping monitoring device performs the method described in any of the first aspects.
[0016] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in any of the first aspects.
[0017] Fifthly, embodiments of this application provide a computer program product that, when run on a terminal device, causes the terminal device to execute the method described in any one of the first aspects.
[0018] It is understood that the beneficial effects of the second to fifth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here.
[0019] Compared with the prior art, the beneficial effects of this application embodiment are as follows: by collecting speed-like variable signals and power-like variable signals of the control loop with two continuous integral elements of the measured power generation unit within a preset time period, oscillation damping information can be captured at the power generation unit port. It is only necessary to construct a time-domain estimation expression of the real part of the eigenvalue of the broadband oscillation and process the signal data to monitor the damping status of the broadband oscillation introduced by various power generation units without having to perform high-dimensional modeling of the entire system. It has high accuracy and strong feasibility. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 This is a flowchart of a damping monitoring method provided in an embodiment of this application;
[0022] Figure 2 This is a schematic diagram of a quasi-electromechanical oscillation ring constructed using a control loop with two consecutive integral elements, provided in an embodiment of this application.
[0023] Figure 3 This is a schematic diagram illustrating the final estimated value of the real part of the eigenvalue obtained through iterative adjustment according to an embodiment of this application;
[0024] Figure 4 This is a structural block diagram of a damping monitoring device provided in one embodiment of this application. Detailed Implementation
[0025] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.
[0026] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.
[0027] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.
[0028] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."
[0029] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0030] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.
[0031] The broadband oscillation damping monitoring method for power systems provided in this application embodiment can be applied to new power systems containing a large number of new energy sources and power electronic devices. It is used for a broadband oscillation damping online monitoring solution. The method is executed by a broadband oscillation damping monitoring device for power systems, which consists of software and / or hardware and is generally integrated into a broadband oscillation damping monitoring device for power systems. The device is installed at the power generation unit port of the power system.
[0032] Figure 1 This is a flowchart of the power system broadband oscillation damping monitoring method provided in this embodiment. Figure 1 As shown, the broadband oscillation damping monitoring method for power systems includes the following steps:
[0033] S11, obtain the time-domain estimation expression of the real part of the eigenvalue of the measured power generation unit.
[0034] Before practical application, the time-domain estimation expression of the real part of the eigenvalue of the measured power generation unit is obtained through derivation. The derivation process is based on the dominant oscillation mode involved in the control loop of the measured power generation unit with two continuous integral elements.
[0035] In practical applications, a time-domain estimation expression for the real part of the eigenvalues, derived in advance, is obtained. This time-domain estimation expression can be stored in the storage unit of the monitoring device and can be obtained by reading the storage unit or by retrieving it from a cloud storage platform via network communication.
[0036] The derivation of the time-domain estimation expression for the real part of the eigenvalues is as follows:
[0037] Construct a state-space model of the power system containing the measured power generation units in the frequency domain: Wherein, the measured power generation unit is the i-th power generation unit in the power system, ΔSV 1,i (s) and ΔSV 2,i ΔZ(s) represents the first and second state variables involved in a control loop of the measured power generation unit with two consecutive integral elements, and ΔZ(s) represents all other state variables of the measured power generation unit besides the first and second state variables. Let be the state matrix, and s be the Laplace operator.
[0038] ΔSV 1,i (s) and ΔSV 2,i (s) are the variables involved in a control loop with two consecutive integral elements selected for constructing the "quasi-electromechanical oscillating loop". The structure of the quasi-electromechanical oscillating loop is as follows: Figure 2 As shown.
[0039] Suppose the state equation associated with the second state variable is: sΔSV 2,i (s)=cF(s); where cF(s) is the frequency domain expression related to ΔSV. 2,i F(s) is a related function. Depending on the control loop being analyzed, F(s) may be a single variable or a multivariate operation involving addition, subtraction, multiplication, and division (but excluding the negation operation). c is the constant part of cF(s) excluding all variables. The specific value of c varies depending on the control loop being analyzed.
[0040] By simultaneously solving the state-space model and the state equations, we can obtain two relationships in the frequency domain:
[0041]
[0042]
[0043] By combining the two frequency domain relationships described above, and using the eigenvalue σ of the dominant oscillation mode of interest... d ±jw d Replacing the Laplace operator s, and then using Passevar's theorem to transform the obtained relation from the frequency domain to the time domain, we obtain the time-domain estimation expression for the real part of the eigenvalues of the dominant oscillation modes involved in the measured power generation unit: Among them, signal It is a type of speed variable signal ΔSV 2,i ΔSV is obtained by the transformation of (t). 2,i (t) is ΔSV 2,i The time-domain form of (s), the signal It is obtained by transforming the power variable signal F(t), where F(t) is the time-domain form of F(s), and F(s) is the part of cF(s) excluding the constant; t is the time variable.
[0044] As can be understood from the above description, in this embodiment, the damping information of broadband oscillation is captured based on signal measurement, processing and transformation, without the need to establish a high-dimensional model, thus avoiding the possible curse of dimensionality in calculation and analysis.
[0045] S12, within a preset time period, acquire speed-like variable signals and power-like variable signals of the control loop of the measured power generation unit with two continuous integral elements.
[0046] Speed variable signal ΔSV 2,i (t) is the value of the speed-like variable of the measured power generation unit at time t.
[0047] The power variable signal F(t) is related to ΔSV 2,i (t) related functions.
[0048] In practical applications, the speed variable signal ΔSV 2,i The power variable signal F(t) and the power variable signal F(t) are measured by a phasor measurement unit (PMU).
[0049] S13, perform a Fourier transform on the speed variable signal, and obtain the angular frequency of the dominant oscillation mode involved in the control loop from the amplitude-frequency characteristic image obtained by the transform.
[0050] Amplitude-frequency characteristic refers to the frequency-amplitude scatter plot of the signal obtained by Fourier transform. The angular frequency of the dominant oscillation mode involved in the control loop of the measured power generation unit with two continuous integral elements can be obtained from the plot.
[0051] S14. Select a dominant oscillation mode of interest and substitute the angular frequency, speed-like variable signal, and power-like variable signal into the time-domain estimation expression of the real part of the eigenvalue for calculation.
[0052] Select a dominant oscillation mode of interest at an angular frequency w d At this point, σ is set. d The initial value is 0.
[0053] The speed variable signal ΔSV 2,i (t) multiplied by the exponential function Then at angular frequency wd Perform Fourier decomposition at the point to obtain the signal.
[0054] Multiply the power variable signal F(t) by an exponential function Then at angular frequency w d Perform Fourier decomposition at the point to obtain the signal.
[0055] Signal and signal Substituting the calculation into the right-hand side of the time-domain estimation expression for the real part of the eigenvalues, i.e. Preliminary estimates of the real part of the eigenvalues of the dominant oscillation mode of interest, σ. d0 .
[0056] S15, through iterative adjustment, obtains the final estimate of the real part of the eigenvalue of the dominant oscillation mode of interest.
[0057] Figure 3 This is a schematic diagram illustrating the final estimated value of the real part of the eigenvalue obtained through iterative adjustment, as provided in this embodiment.
[0058] like Figure 3 As shown, the real part of the eigenvalues is solved by iterative enumeration, specifically including the following steps:
[0059] S151, the preliminary estimated value σ d0 With σ d Compare the initial values to determine σ. d0 -σ d Is it less than the preset error u? If yes, proceed to step S152; otherwise, proceed to step S153.
[0060] The error u is set according to the actual needs of the project, and u is a positive value; as an example, the value in this embodiment is 0.01.
[0061] S152, the preliminary estimated value σ d0 The final estimate of the real part of the eigenvalue of the dominant oscillation mode of interest is output.
[0062] If the preliminary estimated value σ d0 If the condition in step S151 is satisfied, then the current σ can be considered to be satisfied. d The value of σ must be such that the equality of the time-domain estimation expression for the real part of the eigenvalue holds. If the condition is not met, then σ needs to be adjusted. d The value is iteratively corrected.
[0063] S153, σ d The value is changed to σ d ±r.
[0064] Where r is the correction value,
[0065] S154, according to the modified σ d The signal was recalculated. and signal
[0066] S155 will update the signal and signal Substituting the values into the right-hand side of the time-domain estimation expression for the real part of the eigenvalues, we obtain a preliminary estimate σ of the real part of the eigenvalues of the dominant oscillation mode of interest. d0 .
[0067] S156, the revised preliminary estimate σ d0 With the changed σ d Compare until σ d0 -σ d Less than the preset error u.
[0068] By acquiring and processing signals, the real part of the eigenvalues of the dominant oscillation mode is calculated, thereby enabling the monitoring of the damping of broadband oscillations introduced by a large number of power electronic converters, in addition to the low-frequency oscillation mode dominated by generators.
[0069] The real part of the eigenvalue can be used to observe whether the damping of the power system is sufficient. When the real part of the eigenvalue approaches 0 or is greater than 0, it indicates that the damping of the power system is insufficient. Damping information can reflect the convergence of power oscillations in the system. By adjusting the damping to a reasonable range, broadband oscillations can be suppressed.
[0070] Corresponding to the damping monitoring method in the above embodiments, Figure 4 A structural block diagram of the damping monitoring device provided in the embodiments of this application is shown. For ease of explanation, only the parts related to the embodiments of this application are shown.
[0071] Reference Figure 4 The damping monitoring device 400 includes:
[0072] The expression acquisition unit 410 is used to acquire the time-domain estimation expression of the real part of the eigenvalues of the measured power generation unit under the dominant oscillation mode involved in the control loop of the measured power generation unit with two consecutive integral elements.
[0073] The phasor measurement unit 420 is used to acquire, within a preset time period, the speed-like variable signal and the power-like variable signal of the control loop of the measured power generation unit with two continuous integral elements.
[0074] The signal transformation unit 430 is used to perform Fourier transform on the speed variable signal and obtain the angular frequency of the dominant oscillation mode involved in the control loop from the amplitude-frequency characteristic image obtained by the transformation.
[0075] The computation unit 440 is used to, under a selected dominant oscillation mode of interest, substitute the angular frequency, speed-like variable signal, and power-like variable signal into the time-domain estimation expression of the real part of the eigenvalues to obtain a preliminary estimate of the real part of the eigenvalues of the dominant oscillation mode of interest. Then, by iteratively adjusting the preliminary estimate of the real part of the eigenvalues, the final estimate of the real part of the eigenvalues of the dominant oscillation mode of interest is obtained.
[0076] In this embodiment, the expression acquisition unit 410 is specifically used to derive the time-domain estimation expression of the real part of the eigenvalue, or to obtain the time-domain estimation expression of the real part of the eigenvalue from the local storage unit or the network storage device.
[0077] The derivation process of the time-domain estimation expression for the real part of the eigenvalues by the expression acquisition unit 410 includes:
[0078] Construct a state-space model of the power system containing the measured power generation units in the frequency domain: Wherein, the measured power generation unit is the i-th power generation unit in the power system, ΔSV 1,i (s) and ΔSV 2,i ΔZ(s) represents the first and second state variables involved in a control loop of the measured power generation unit with two consecutive integral elements, and ΔZ(s) represents all other state variables of the measured power generation unit besides the first and second state variables. Let be the state matrix, and s be the Laplace operator.
[0079] Suppose the state equation associated with the second state variable is: sΔSV 2,i (s)=cF(s); where cF(s) is the frequency domain expression related to ΔSV. 2,i (s) is a function related to c, where c is the constant part of cF(s) excluding all variables.
[0080] By simultaneously solving the state-space model and the state equations, we can obtain two relationships in the frequency domain:
[0081]
[0082]
[0083] We combine the two relationships in the frequency domain and use the eigenvalue σ of the dominant oscillation mode of interest. d ±jw d Replacing the Laplace operator s, the resulting relation is transformed from the frequency domain to the time domain, yielding a time-domain estimation expression for the real part of the eigenvalues of the dominant oscillation modes involved in the measured power generation unit:
[0084] Among them, signal It is a type of speed variable signal ΔSV 2,i The speed-like variable signal ΔSV obtained by (t) transformation 2,i (t) represents the second state variable ΔSV. 2,i The time-domain form of (s), the signal It is obtained by transforming the power variable signal F(t), which is the time-domain form of F(s), and F(s) is the part of cF(s) excluding the constant; t is the time variable.
[0085] In practical applications, after the expression acquisition unit 410 obtains the time-domain estimation expression of the real part of the eigenvalue, the signal transformation unit 430 is used to transform the speed variable signal ΔSV into a time-domain estimation expression. 2,i (t) multiplied by the exponential function Then at angular frequency w d Perform Fourier decomposition at the point to obtain the signal.
[0086] The signal transformation unit 430 is also used to multiply the power variable signal F(t) by an exponential function. Then at angular frequency w d Perform Fourier decomposition at the point to obtain the signal.
[0087] The arithmetic unit 440 is specifically used to, in a selected dominant oscillation mode of interest, at an angular frequency ω d At this point, σ is set. d The initial value is 0; substitute the transformed signal output by the signal transformation unit 430 into the calculation formula on the right side of the time-domain estimation expression for the real part of the eigenvalue: Preliminary estimates of the real part of the eigenvalues of the dominant oscillation mode of interest, σ. d0 .
[0088] Furthermore, the damping monitoring device 400 also includes an iterative adjustment unit 450, used to obtain a preliminary estimate of the real part of the eigenvalue σ. d0 Next, the preliminary estimated value σ d0 With σ d Compare the initial values to determine σ. d0 -σ d Whether it is less than the preset error u, where u is a positive value.
[0089] If so, the preliminary estimated value σ d0 The final estimate of the real part of the eigenvalue of the dominant oscillation mode of interest is output.
[0090] If not, σ d The value is changed to σ d ±r; based on the modified σd The signal was recalculated. and signal Where r is the correction value, Updated signal and signal Substituting the values into the right-hand side of the time-domain estimation expression for the real part of the eigenvalues, we obtain a preliminary estimate σ of the real part of the eigenvalues of the dominant oscillation mode of interest. d0 The revised preliminary estimate σ d0 With the changed σ d Compare until σ d0 -σ d Less than the preset error u.
[0091] It should be noted that the information interaction and execution process between the above modules / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.
[0092] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.
[0093] This application also provides a damping monitoring device, including any of the damping monitoring devices described in the above embodiments, wherein the damping monitoring device is installed at the port of the power generation unit.
[0094] In this embodiment, the damping monitoring device is based on the processing and transformation of signals captured by the power generation unit port, which has high accuracy and strong feasibility, without the need for high-dimensional modeling of the entire system.
[0095] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps described in the various method embodiments above.
[0096] This application provides a computer program product that, when run on a mobile terminal, enables the mobile terminal to implement the steps described in the above-described method embodiments.
[0097] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of this application can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include at least: any entity or device capable of carrying computer program code to a photographing device / terminal device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium. Examples include USB flash drives, portable hard drives, magnetic disks, or optical disks. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electrical carrier signals or telecommunication signals.
[0098] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.
[0099] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.
[0100] In the embodiments provided in this application, it should be understood that the disclosed apparatus / devices and methods can be implemented in other ways. For example, the apparatus / device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.
[0101] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.
[0102] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.
Claims
1. A method of power system wideband oscillation damping monitoring, characterized by, Comprising: Obtaining a time-domain estimation expression of a real part of an eigenvalue of a dominant oscillation mode of a measured power generation unit under a control loop involving two continuous integral links; wherein the measured power generation unit comprises a power electronic converter type power supply; Collecting a speed-like variable signal and a power-like variable signal of the control loop of the measured power generation unit within a preset time period; Performing Fourier transform on the speed-like variable signal, and obtaining an angular frequency of the dominant oscillation mode of the control loop from an amplitude-frequency characteristic image obtained by the transform; the dominant oscillation mode comprises a broadband oscillation mode; Selecting a dominant oscillation mode of interest, and substituting the angular frequency, the speed-like variable signal and the power-like variable signal into the time-domain estimation expression of the real part of the eigenvalue for calculation, and obtaining a final estimation value of the real part of the eigenvalue of the dominant oscillation mode of interest through iterative adjustment; Obtaining a time-domain estimation expression of a real part of an eigenvalue of a dominant oscillation mode of a measured power generation unit, comprising: Construct a state-space model of the power system containing the measured power generation unit in the frequency domain: The measured power generation unit is the first in the power system. i One power generation unit, Δ SV 1,i ( s ) and Δ SV 2,i ( s ) are the first and second state variables involved in a control loop of the measured power generation unit having two consecutive integral elements, Δ Z ( s ) refers to all other state variables of the measured power generation unit besides the first and second state variables. The state matrix, s The Laplace operator is used; the control loop is a quasi-electromechanical oscillatory loop. Assume that the state equation related to the second state variable is: ; wherein cF ( s ) is a function related to Δ SV 2,i ( s ) in the frequency domain, c is a constant part of cF ( s ) except for all variables; By combining the state space model and the state equation, two relationship expressions in the frequency domain can be obtained: ； ； simultaneously solving the two relations in the frequency domain and using the eigenvalue of the dominant oscillation mode of interest instead of the Laplace operator s converting the resulting relation from the frequency domain to the time domain, obtaining a time-domain estimation expression of the real part of the eigenvalue of the dominant oscillation mode involved in the measured power generating unit: ; Among them, signal It is the type of speed variable signal Δ SV 2,i ( t The speed variable signal Δ obtained by transformation SV 2,i ( t ) is the second state variable Δ SV 2,i ( s The time-domain form of the signal It is the power variable signal of the class F ( t The power variable signal obtained by transformation F ( t )for F ( s The time-domain form of ) F ( s )for cF ( s The part excluding constants; t It is a time variable; Substituting the angular frequency, the speed-like variable signal and the power-like variable signal into the time-domain estimation expression of the real part of the eigenvalue for calculation, comprising: selecting a dominant oscillation mode of interest at an angular frequency w d setting an initial value of 0 at the angular frequency σ d of interest The class speed variable signal Δ SV 2,i ( t ) is multiplied by an exponential function , and Fourier decomposition is performed at the angular frequency w d to obtain a signal ; multiplying the class power variable signal F ( t ) by an exponential function and Fourier decomposing the result at the angular frequency w d to obtain a signal ; substituting said signal and said signal into the calculation formula on the right side of the equality of the time-domain estimated expression of the real part of the eigenvalue: , obtaining a preliminary estimated value of the real part of the eigenvalue of the dominant oscillation mode of interest σ d0 ; Obtaining a final estimation value of the real part of the eigenvalue of the dominant oscillation mode of interest through iterative adjustment, comprising: comparing the initial value of the preliminary estimate value σ d0 with σ d a preset error value, determining whether the initial value is less than the preset error value u , u a positive value. If so, the preliminary estimate of the eigenvalue real part of the dominant oscillation mode of interest is updated as follows: σ d0 as the final estimate of the eigenvalue real part of the dominant oscillation mode of interest, and output. If not, the value of σ d is changed to ; according to the changed σ d , the signal and the signal are recalculated, wherein r is a correction value, ; the updated signal and the signal are substituted into the calculation formula on the right side of the equality of the time-domain estimation expression of the real part of the eigenvalue of the dominant oscillation mode of interest, and the preliminary estimation value of the real part of the eigenvalue of the dominant oscillation mode of interest is obtained again σ d0 The changed preliminary estimation value σ d0 is compared with the changed σ d until is less than the preset error u .
2. A power system wide area oscillation damping monitoring apparatus characterized by comprising: Comprising: An expression obtaining unit, configured to obtain a time-domain estimation expression of a real part of an eigenvalue of a dominant oscillation mode of a measured power generation unit under a control loop involving two continuous integral links; wherein the measured power generation unit comprises a power electronic converter type power supply; A phasor measurement unit, configured to collect a speed-like variable signal and a power-like variable signal of the control loop of the measured power generation unit within a preset time period; A signal conversion unit, configured to perform Fourier transform on the speed-like variable signal, and obtain an angular frequency of the dominant oscillation mode of the control loop from an amplitude-frequency characteristic image obtained by the transform; the dominant oscillation mode comprises a broadband oscillation mode; An operation unit, configured to substitute the angular frequency, the speed-like variable signal and the power-like variable signal into the time-domain estimation expression of the real part of the eigenvalue for calculation under a selected dominant oscillation mode of interest, and obtain a final estimation value of the real part of the eigenvalue of the dominant oscillation mode of interest through iterative adjustment; The expression obtaining unit is specifically configured to: constructing a state space model of a power system in a frequency domain, the power system comprising a measured power generating unit; wherein the measured power generating unit is an i i th power generating unit in the power system, Δ SV 1,i ( s ) and Δ SV 2,i ( s ) are a first state variable and a second state variable involved in a control loop of the measured power generating unit having two consecutive integral links, Δ Z ( s ) is all other state variables of the measured power generating unit except the first state variable and the second state variable, is a state matrix, s is a Laplace operator; the control loop is a class of electromechanical oscillation loops; Assume that the state equation related to the second state variable is: ; wherein cF ( s ) is a function related to Δ SV 2,i ( s ) in the frequency domain, c is a constant part of cF ( s ) except for all variables; By combining the state space model and the state equation, two relationship expressions in the frequency domain can be obtained: ； ； simultaneously solving the two relations in the frequency domain and using the eigenvalue of the dominant oscillation mode of interest instead of the Laplace operator s converting the resulting relation from the frequency domain to the time domain, obtaining a time-domain estimation expression of the real part of the eigenvalue of the dominant oscillation mode involved in the measured power generating unit: ; wherein the signal is obtained by transforming the class speed variable signal Δ SV 2,i ( t ) which is a time domain form of the second state variable Δ SV 2,i ( t ), the signal SV 2,i ( s ) is obtained by transforming the class power variable signal Δ F ( t ) which is a time domain form of F t F ( s ), F ( s ) is the part of cF ( s ) excluding a constant; t is a time variable; The signal conversion unit is also configured to multiply the class speed variable signal Δ SV 2,i ( t ) by an exponential function , and then perform Fourier decomposition on the angular frequency w d to obtain a signal ; The signal transformation unit is also configured to multiply the class power variable signal F ( t ) by an exponential function and to perform a Fourier decomposition at the angular frequency w d to obtain a signal ; The operation unit is specifically configured to, in the selected one dominant oscillation mode of interest, at the angular frequency w d , set the initial value of 0; substitute the transformed signal output by the signal transformation unit into the calculation formula on the right side of the time-domain estimation expression of the real part of the eigenvalue: σ d , to obtain the preliminary estimation value of the real part of the eigenvalue of the dominant oscillation mode of interest σ d0 ; Further comprising: An iterative adjustment unit is configured to compare the initial value of the preliminary estimation value with an initial value of the target value, and determine whether the initial value of the preliminary estimation value is less than a preset error σ d0 With σ d the initial value of the target value, and determine whether the initial value of the preliminary estimation value is less than a preset error u , u a positive value. If so, the preliminary estimate of the eigenvalue real part of the dominant oscillation mode of interest is updated as follows: σ d0 as the final estimate of the eigenvalue real part of the dominant oscillation mode of interest, and output. If not, the value of σ d is changed to ; according to the changed σ d , the signal and the signal are recalculated, wherein r is a correction value, ; the updated signal and the signal are substituted into the calculation formula on the right side of the equality of the time-domain estimation expression of the real part of the eigenvalue of the characteristic value of the signal of interest, and the preliminary estimation value of the real part of the eigenvalue of the dominant oscillation mode of the signal of interest is obtained again σ d0 The changed preliminary estimation value σ d0 is compared with the changed σ d , until is less than the preset error u .
3. A power system wide-area oscillation damping monitoring device characterized by comprising: Comprising: The damping monitoring device of claim 2; The damping monitoring device is arranged at a port of the power generation unit.
4. A computer-readable storage medium storing a computer program, the computer program comprising instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 3. The computer program is executed by the processor to implement the method of claim 1.