False data injection method for broadband synchronous phasor of power system

Abstract

The invention discloses a false data injection method for a broadband synchronous phasor of a power system, and relates to the technical field of wide area measurement and control of the power system, and the method comprises the steps: collecting broadband synchronous phasor measurement unit (WPMU) data of a target area; when it is detected that broadband oscillation occurs in the power grid and the oscillation duration exceeds a preset threshold value, the attack starting opportunity is judged; randomly selecting the measurement value of one oscillation mode as a false data injection target, and obtaining the measurement value of the oscillation mode; constructing and solving a multi-target nonlinear programming model, generating tampered WPMU data, and injecting the tampered WPMU data into a scheduling center through man-in-the-middle attack MITM or protocol vulnerabilities; and monitoring whether the power system cuts off the target wind power plant or not, and if the target wind power plant is not successfully cut off, performing attack again. According to the method, the data tampering quantity can be reduced, the attack concealment is improved, the risk found by a detected system is reduced, and a powerful guarantee is provided for safe operation of a power system.

Description

Technical Field

[0001] The present invention relates to the technical field of wide-area measurement and control of power systems, in particular to a false data injection method for wide-band synchronized phasors of power systems. Background Art

[0002] With the growing global demand for clean energy, large-scale wind power integration has become an inevitable trend in power system development. However, the intermittent and fluctuating nature of wind power, coupled with the extensive use of power electronics, has led to an increasing problem of broadband oscillations in power grids. Broadband oscillations can damage power equipment, degrade power quality, and even cause grid disconnection and widespread blackouts, seriously threatening the safe and stable operation of power systems.

[0003] Power-based source tracing is a common method for analyzing broadband oscillation sources. This technique measures the phase difference between node voltage and current to calculate the direction of the oscillating energy flow and, therefore, the location of the oscillation source. However, this method has limitations. An attacker could inject false data to alter the measured values, thereby misleading the dispatch center's judgment of the oscillation source. This could lead to the incorrect removal of wind farms and significant economic losses. Summary of the Invention

[0004] The present invention is proposed in view of the problems existing in the existing false data injection method for wide-band synchronized phasors in power systems. Therefore, the problem to be solved by the present invention is how to provide a false data injection method for wide-band synchronized phasors in power systems.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] In a first aspect, the present invention provides a false data injection method for wideband synchronized phasors in a power system, comprising continuously collecting wideband synchronized phasor measurement unit (WPMU) data in a target area through a wide area measurement system (WAMS), including the wideband voltage amplitude and phase of each node and the wideband current amplitude and phase of each branch;

[0007] When a broadband oscillation is detected in the power grid and the duration of the oscillation exceeds a preset threshold, it is determined that the attack is initiated;

[0008] Select a measurement value of an oscillation mode as a false data injection target to obtain the measurement value of the oscillation mode;

[0009] Construct and solve a multi-objective nonlinear programming model, wherein the multi-objective nonlinear programming model is composed of multiple objective functions, generate tampered WPMU data, and inject it into the dispatch center through a man-in-the-middle attack MITM or protocol vulnerability;

[0010] Monitor whether the power system has cut off the target wind farm. If the target wind farm is not successfully cut off, dynamically adjust the weights of each objective function to attack again.

[0011] As a preferred embodiment of the false data injection method for wide-band synchronized phasors of a power system according to the present invention, the measured values of the oscillation mode include the voltage amplitude and phase measurement values U and θ of the wide-band oscillation target mode at the PCC point where multiple wind farms are connected to the power grid. U , the measured values of the current amplitude and phase of the broadband oscillation target mode in the m transmission lines connected to the PCC point I i and

[0012] As a preferred solution of the false data injection method for wide-band synchronized phasors in power systems described in the present invention, the multi-objective nonlinear programming model includes maximizing the attack effect and minimizing the amount of data tampering as objective functions, and the constraints include power method traceability misjudgment constraints, Kirchhoff's current law constraints, and variable range constraints; the multi-objective nonlinear programming model is solved using a weighted sum method;

[0013] Maximize the objective function P of the attack effect impact Expressed as:

[0014]

[0015] Where n is the number of wind farms connected to the grid, P i is the active power delivered by wind farm i, b i Used to define whether wind farm i is an attack target: If wind farm i is an attack target, then b i =1; if wind farm i is not the target of attack, then b i =0;

[0016] The objective function for minimizing the amount of data tampering includes the objective function F1 for minimizing the amount of amplitude tampering and the objective function F2 for minimizing the amount of phase tampering, which are expressed as:

[0017]

[0018] Among them, ΔU and Δθ U are the tampering amounts of the voltage amplitude and phase data of the broadband oscillation target mode at the PCC point where multiple wind farms are connected to the grid, ΔI i and Δθ Ii are the tampering amounts of the current amplitude and phase data of the broadband oscillation target mode in the m transmission lines connected to the PCC point.

[0019] As a preferred solution of the false data injection method for wide-band synchronized phasors in power systems according to the present invention, the expression of the power method source tracing misjudgment constraint is:

[0020]

[0021] Among them, sgn(·) is the sign function, P i_TEFL and P' i_TEFL are the energy flow power of wind farm i before and after the false data injection, is the voltage amplitude after false data injection, is the current amplitude after false data injection, is the voltage phase after false data injection, is the current phase after false data injection.

[0022] As a preferred solution of the false data injection method for wide-band synchronized phasors in power systems according to the present invention, the expression of Kirchhoff's current law constraint is:

[0023]

[0024] Where m is the number of transmission lines, is the current amplitude after false data injection, is the current phase angle after false data injection.

[0025] As a preferred solution of the false data injection method for wide-band synchronized phasors in power systems according to the present invention, the expression of the variable range constraint is:

[0026]

[0027] Among them, τ1, τ2, τ3 and τ4 are tampering coefficients.

[0028] As a preferred solution of the false data injection method for wide-band synchronized phasors in power systems according to the present invention, the method of solving the multi-objective nonlinear programming model using the weighted sum method includes constructing an overall objective function, solving the model using power method source tracing misjudgment constraints, Kirchhoff's current law constraints, and variable range constraints as constraints. The overall objective function is expressed as follows:

[0029]

[0030] Among them, ω mag 、ω phase and ω p The objective functions F1, F2 and P are impact The weight of .

[0031] In a second aspect, the present invention provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: when the processor executes the computer program, the steps of a false data injection method for a wide-band synchronized phasor of a power system are implemented.

[0032] In a third aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, the steps of a false data injection method for a wide-band synchronized phasor of a power system are implemented.

[0033] The beneficial effects of the present invention are as follows: by establishing a multi-objective nonlinear programming model, the present invention comprehensively considers the two goals of attack effect and data tampering amount, and while ensuring the attack effect, it reduces the amount of data tampering as much as possible, improves the concealment of the attack, and reduces the risk of being discovered by the detection system.

[0034] This invention sets a power-method traceability misjudgment constraint to ensure that the power flow is sign-reversed after tampering, thereby preventing the dispatch center from misjudging the oscillation source. The introduction of this constraint makes the attack more precise and can effectively interfere with the power-method traceability results.

[0035] This invention can be applied to network security protection testing in power dispatching centers, helping to evaluate the anti-attack capabilities of broadband oscillation tracing algorithms. By simulating false data injection attacks, it is possible to test whether the dispatching center's existing security protection mechanisms can effectively resist such attacks and discover loopholes and weaknesses in the algorithms. At the same time, it provides a basis for optimizing power system defense strategies. Based on the test results, targeted improvement measures can be proposed, such as strengthening data encryption, improving monitoring mechanisms, and optimizing algorithm design, to improve the security and reliability of the power system. In practical applications, it can be integrated into the power system's security assessment platform for regular testing and evaluation, providing strong guarantees for the safe operation of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 A flow chart of a method for injecting false data into a wide-band synchronized phasor of a power system;

[0038] Figure 2 This is a schematic diagram of the grid-connected system architecture of four direct-drive wind farms;

[0039] Figure 3This is a schematic diagram of the broadband oscillation tracing results before the injection of false data;

[0040] Figure 4 Schematic diagram of broadband oscillation tracing results after false data injection. DETAILED DESCRIPTION

[0041] To make the above-mentioned objects, features, and advantages of the present invention more easily understood, the following detailed description of the specific embodiments of the present invention is given in conjunction with the accompanying drawings. It is obvious that the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in this field without creative work should fall within the scope of protection of the present invention.

[0042] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0043] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it constitute a separate or selective embodiment that is mutually exclusive with other embodiments.

[0044] Reference Figures 1-4 , which is the first embodiment of the present invention, provides a false data injection method for a wide-band synchronized phasor of a power system, comprising:

[0045] S1: Continuously collect broadband synchronized phasor measurement unit (WPMU) data in the target area through the wide area measurement system (WAMS), including broadband voltage amplitude and phase of each node and broadband current amplitude and phase of each branch.

[0046] Specifically, taking the four-direct-drive wind farm grid-connected system as an example, its system architecture is as follows: Figure 2 As shown in the figure, four wind farms with different parameters are connected to two receiving systems via transformers and transmission lines. To construct the tampering parameters for false data injection, the data required include the amplitude and phase of each modal voltage at the PCC point, as well as the amplitude and phase of each modal current in each branch. After the system reaches steady state, changes in the internal damping of the wind farms cause broadband oscillations in the grid-connected system.

[0047] S2: When a broadband oscillation is detected in the power grid and the duration of the oscillation exceeds a preset threshold, it is determined that the attack is initiated;

[0048] Specifically, when it is detected that the power grid has a broadband oscillation and lasts for more than 0.5 s, it is determined as the attack start timing.

[0049] S3: Select the measurement value of any oscillation mode as the false data injection target, and obtain the measurement value of the oscillation mode;

[0050] Specifically, select the measurement value of any oscillation mode as the injection target. The measurement value of the oscillation mode includes the voltage amplitude and its phase U, θ of the target mode at the PCC point U , and the current amplitude and its phase I of the target mode in the m transmission lines connected to the PCC point i ,

[0051] S4: Construct a multi-objective nonlinear programming model and solve it. Among them, the multi-objective nonlinear programming model is composed of multiple objective functions, generate tampered WPMU data, and inject it into the dispatching center through a man-in-the-middle attack MITM or a protocol vulnerability;

[0052] Specifically, establish a multi-objective nonlinear programming model to achieve the balance between the attack effect and the data tampering amount. Take maximizing the attack effect and minimizing the data tampering amount as the objective functions, and the constraint conditions include the misjudgment constraint of power method traceability, the Kirchhoff current law constraint and the variable range constraint; use the weighted sum method to solve the multi-objective nonlinear programming model.

[0053] The objective function P for maximizing the attack effect impact is:

[0054]

[0055] Among them, n (n < m) is the number of wind farms connected to the power grid by wind power, and P i is the active power sent out by wind farm i, and b i is used to define whether wind farm i is an attack target:

[0056] If wind farm i is an attack target, then b i = 1; if wind farm i is not an attack target, then b i = 0.

[0057] Define the objective functions of the amplitude tampering amount F1 and the phase tampering amount F2 respectively, and the expressions are:

[0058]

[0059] Among them, ΔU and Δθ U are respectively the tampering amounts of the voltage amplitude and its phase data of the broadband oscillation target mode at the PCC point where multiple wind farms are connected to the power grid, and ΔI i and Δθ Iiare the tampering amounts of the current amplitude and phase data of the broadband oscillation target mode in the five transmission lines connected to the PCC point.

[0060] By minimizing these two objective functions, the degree of data tampering can be reduced and the concealment of the attack can be improved.

[0061] In order to ensure that the sign of the energy flow power is reversed after tampering, it is necessary to add a power method traceability misjudgment constraint. For wind farm i, the energy flow power P of a certain oscillation mode before the false data is injected i_TEFL The calculation is as follows:

[0062]

[0063] The criterion for tracing the broadband oscillation source of the power method is: define the voltage and current directions as the same as the positive direction, and calculate when P i_TEFL When <0, the power equipment or network is determined to be the oscillation source under the oscillation mode, otherwise it is not the oscillation source.

[0064] For multi-port devices, the power absorbed or released is the sum of the power of each port. Energy flow power is a key indicator for power source tracing. Changing its sign can mislead the dispatch center's judgment of the oscillation source. The specific construction of the power source tracing misjudgment constraint is as follows:

[0065]

[0066] Among them, sgn(·) is the sign function, specifically:

[0067]

[0068] Calculate the energy flow power P' of wind farm i after false data injection i_TEFL , specifically:

[0069]

[0070] Among them, sgn(·) is the sign function, P i_TEFL and P' i_TEFL are the energy flow power of wind farm i before and after the false data injection, is the voltage amplitude after false data injection, is the current amplitude after false data injection, is the voltage phase after false data injection, is the current phase after false data injection.

[0071] To ensure node current balance, the five branch current vectors at the PCC point after tampering must satisfy Kirchhoff's current law. Kirchhoff's current law is one of the basic laws of power system analysis. When injecting false data, this constraint must be met:

[0072]

[0073] Where m is the number of transmission lines, is the current amplitude after false data injection, is the current phase angle after false data injection.

[0074] To prevent the injected false data from being identified by bad data detection, it is necessary to limit the value of each tampered amount, that is, the variable range constraint, which is expressed as:

[0075]

[0076] Among them, τ1, τ2, τ3 and τ4 are the maximum tampering coefficients.

[0077] When solving the model, the weighted sum method is used to transform the multi-objective into a single objective function, which can be expressed as:

[0078]

[0079] Among them, ω mag , τ phase and ω p The objective functions F1, F2 and P are impact The selection of these weight coefficients needs to be adjusted according to the actual attack requirements and the characteristics of the power system. For example, if more attention is paid to the concealment of the attack, ω can be appropriately increased. mag and ω phase If you pay more attention to the attack effect, you can increase ω appropriately. p value.

[0080] The optimal solution to the multi-objective optimization problem is obtained through the optimization algorithm solver, and then the tampered data is injected into the dispatch center through a man-in-the-middle attack or protocol vulnerability.

[0081] S5: Monitor whether the power system has cut off the target wind farm. If the target wind farm is not successfully cut off, dynamically adjust the weights of each objective function to attack again.

[0082] Specifically, by modifying the measurement values in the IEEE C37.111 protocol message and injecting tampered data, the dispatch center calculated the wrong direction of energy flow, misjudging wind farm 1 as the oscillation source and removing it, while the actual oscillation source, wind farm 2, continued to oscillate and remained connected to the grid. Figure 3 and Figure 4 In the figure, the red arrows indicate the direction of energy flow before the injection of false data, and the blue arrows indicate the direction of energy flow after the injection of false data.

[0083] After data injection, the attack's effectiveness needs to be monitored. This can be assessed by analyzing the dispatch center's judgment of the oscillation source, calculated energy flow, and other indicators. If the attack is unsatisfactory, the weights can be dynamically adjusted and the attack reinitiated. If the tampered data still fails to misjudge the oscillation source, the weight of the attack effect can be appropriately increased, the optimization model can be re-solved, and new tampered data can be generated.

[0084] This embodiment also provides a computer device, which is suitable for the case of a false data injection method for wide-band synchronized phasors in power systems, including: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute computer-executable instructions to implement all or part of the steps of the method described in the embodiment of the present invention proposed in the above embodiment.

[0085] This embodiment further provides a storage medium having a computer program stored thereon, which, when executed by a processor, performs the method of any optional implementation of the above embodiment. The storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk, or optical disk.

[0086] The storage medium proposed in this embodiment and the data storage method proposed in the above embodiment belong to the same inventive concept. Technical details not fully described in this embodiment can be found in the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0087] In summary, the present invention establishes a multi-objective nonlinear programming model that comprehensively considers both attack effectiveness and the amount of data tampering. While ensuring attack effectiveness, it minimizes the amount of data tampering, improves the concealment of the attack, and reduces the risk of detection by the detection system. By setting a power method source tracing misjudgment constraint, the sign of the power flow is reversed after tampering, thereby preventing the dispatch center from misjudging the oscillation source. The introduction of this constraint makes the attack more precise and effectively interferes with the power method source tracing results. It can be applied to network security testing of power dispatch centers to help evaluate the attack resistance of broadband oscillation source tracing algorithms. By simulating false data injection attacks, it is possible to test whether the dispatch center's existing security protection mechanisms can effectively resist such attacks and identify vulnerabilities and weaknesses in the algorithms. This also provides a basis for optimizing power system defense strategies. Based on the test results, targeted improvement measures can be proposed, such as strengthening data encryption, improving monitoring mechanisms, and optimizing algorithm design, to improve the security and reliability of the power system. In practical applications, the system can be integrated into the power system security assessment platform for regular testing and evaluation, providing strong guarantees for the safe operation of the power system.

[0088] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for injecting false data into a wide-band synchronized phasor in a power system, characterized by: include, The wide-area measurement system (WAMS) continuously collects broadband synchronized phasor measurement unit (WPMU) data in the target area, including broadband voltage amplitude and phase at each node and broadband current amplitude and phase at each branch. When a broadband oscillation is detected in the power grid and the duration of the oscillation exceeds a preset threshold, it is determined that the attack is initiated; Select a measurement value of an oscillation mode as a false data injection target to obtain the measurement value of the oscillation mode; Construct and solve a multi-objective nonlinear programming model, wherein the multi-objective nonlinear programming model is composed of multiple objective functions, generate tampered WPMU data, and inject it into the dispatch center through a man-in-the-middle attack MITM or protocol vulnerability; Monitor whether the power system has cut off the target wind farm. If the target wind farm is not successfully cut off, dynamically adjust the weights of each objective function to attack again.

2. The method for injecting false data into a wide-band synchronized phasor of a power system according to claim 1, wherein: The measured values of the oscillation mode include the voltage amplitude and phase measurement values U and θ of the broadband oscillation target mode at the PCC point where multiple wind farms are connected to the grid. U , the measured values of the current amplitude and phase of the broadband oscillation target mode in the m transmission lines connected to the PCC point I i and i=1,2,…,m.

3. The method for injecting false data into a wide-band synchronized phasor of a power system according to claim 2, wherein: The multi-objective nonlinear programming model includes maximizing the attack effect and minimizing the amount of data tampering as objective functions, and the constraints include power method traceability misjudgment constraint, Kirchhoff's current law constraint, and variable range constraint; the multi-objective nonlinear programming model is solved using a weighted sum method; Maximize the objective function P of the attack effect impact Expressed as: Where n is the number of wind farms connected to the wind power grid, P i is the active power delivered by wind farm i, b i Used to define whether wind farm i is an attack target: If wind farm i is an attack target, then b i =1; if wind farm i is not the target of attack, then b i =0; The objective function for minimizing the amount of data tampering includes the objective function F1 for minimizing the amount of amplitude tampering and the objective function F2 for minimizing the amount of phase tampering, which are expressed as: Among them, ΔU and Δθ U are the tampering amounts of the voltage amplitude and phase data of the broadband oscillation target mode at the PCC point where multiple wind farms are connected to the grid, ΔI i and Δθ Ii are the tampering amounts of the current amplitude and phase data of the broadband oscillation target mode in the m transmission lines connected to the PCC point.

4. The method for injecting false data into a wide-band synchronized phasor of a power system according to claim 3, wherein: The expression of the power method traceability misjudgment constraint is: Among them, sgn(·) is the sign function, P i_TEFL and P' i_TEFL are the energy flow power of wind farm i before and after the false data injection, is the voltage amplitude after false data injection, is the current amplitude after false data injection, is the voltage phase after false data injection, is the current phase after false data injection.

5. The method for injecting false data into a wide-band synchronized phasor of a power system according to claim 4, wherein: The expression of Kirchhoff's current law constraint is: Where m is the number of transmission lines, is the current amplitude after false data injection, is the current phase angle after false data injection.

6. The method for injecting false data into a wide-band synchronized phasor of a power system according to claim 5, wherein: The expression of the variable range constraint is: Among them, τ1, τ2, τ3 and τ4 are tampering coefficients.

7. The method for injecting false data into a wide-band synchronized phasor of a power system according to claim 6, wherein: The weighted sum method is used to solve the multi-objective nonlinear programming model, which includes constructing an overall objective function and solving the model with power method tracing misjudgment constraint, Kirchhoff's current law constraint, and variable range constraint as constraint conditions. The overall objective function is expressed as follows: Among them, ω mag 、ω phase and ω p The objective functions F1, F2 and P are impact The weight of .

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the false data injection method for wide-band synchronized phasors of a power system according to any one of claims 1 to 7 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the false data injection method for wide-band synchronized phasors of a power system according to any one of claims 1 to 7 are implemented.

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