CN114362245A - Wind power plant attack method and system - Google Patents
Wind power plant attack method and system Download PDFInfo
- Publication number
- CN114362245A CN114362245A CN202210029825.0A CN202210029825A CN114362245A CN 114362245 A CN114362245 A CN 114362245A CN 202210029825 A CN202210029825 A CN 202210029825A CN 114362245 A CN114362245 A CN 114362245A
- Authority
- CN
- China
- Prior art keywords
- current
- attack
- grid
- wind power
- disturbance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/70—Wind energy
- Y02E10/76—Power conversion electric or electronic aspects
Landscapes
- Control Of Eletrric Generators (AREA)
Abstract
The invention discloses a method and a system for attacking a wind power plant, wherein the method comprises the following steps: controlling a direct-hanging disturbance current injection device to inject a broadband current signal into a system, acquiring a system admittance-frequency characteristic curve and a system admittance-frequency characteristic expression based on a voltage signal and a current signal at a grid-connected point, selecting attack modes, and sequencing the attack modes according to the damping ratio; injecting attack current under each attack mode in sequence, wherein each attack lasts for a preset time, monitoring whether the grid-connected current has a divergence trend in each attack process, if so, the attack is successful, otherwise, attacking is performed by using the attack current under the next attack mode; and if all attack currents are unsuccessful, and when the state of the wind power plant or the operation state of the power grid changes, injecting the broadband current signal again, and selecting an attack mode to attack until the attack is successful. According to the method, the disturbance signal is injected at the physical side, so that the identification accuracy and efficiency of the weak points of the wind power plant are improved, and the oscillation risk frequency is effectively identified.
Description
Technical Field
The invention relates to the field of security assessment of power systems, in particular to a method and a system for attacking a wind power plant.
Background
The large-scale renewable energy is connected to the power grid through the power electronic converter, so that the power electronic devices of the power system are continuously increased, and the modern power system gradually develops towards the trend of power electronization. The low inertia, weak interference immunity and non-linear and multi-time scale response characteristics of the high-frequency-ratio broadband power system increase the risk of broadband oscillation of the power electronic power system caused by external risks.
The broadband oscillation is a dynamic process in which electrical quantities (such as voltage, current, power, and the like) caused by interactions between power electronic devices and between the power electronic devices and a power grid periodically fluctuate with time due to the influence of the power system or external factors, and the oscillation frequency changes in a wide range. Due to the interaction of multiple time scales in the wind power grid-connected system, the system may have a potential weak damping oscillation mode, and when disturbance of corresponding frequency occurs in the system, forced oscillation of the wind power grid-connected system in a wide frequency band may occur, and finally the system is unstable. The broadband oscillation problem caused by the wind power grid-connected system seriously affects the equipment safety and the power quality, restricts the efficient consumption of wind power and threatens the safety and stability of a power grid.
With the gradual increase of the number and scale of wind power plants, the dynamic interaction between wind power grid-connected systems is gradually complicated, and the oscillation risk is greatly increased, so that broadband attack on the wind power plants is very necessary, the oscillation risk frequency of the systems can be effectively identified, and effective information is provided for formulating a stable control strategy of the wind power plants.
Disclosure of Invention
Therefore, the technical problem to be solved by the invention is to overcome the defect that the wind power plant in the prior art is easy to generate broadband oscillation, so that a wind power plant attack method and a wind power plant attack system are provided.
In order to achieve the purpose, the invention provides the following technical scheme:
in a first aspect, an embodiment of the present invention provides a wind farm attack method, including: the method comprises the following steps that a direct-hanging disturbance current injection device is installed at a grid-connected point of a wind power plant in parallel, the direct-hanging disturbance current injection device is controlled to inject a broadband current signal into a wind power grid-connected system, and voltage and current signals at the grid-connected point are collected; acquiring a system admittance-frequency characteristic curve based on the acquired voltage and current signals at the grid-connected point, identifying to obtain an admittance-frequency characteristic expression of the system, and calculating the frequency and damping ratio of each mode of the system; setting the modes with the damping ratio smaller than a preset damping value as attack modes according to the frequency and the damping ratio of each mode of the system, and sequencing the attack modes according to the damping ratio; according to the sequence of the attack modes, sequentially injecting attack current under each attack mode, wherein each attack current continuously attacks for a preset time, monitoring whether the grid-connected current of the wind power plant has a divergence trend within the attack time of each attack current, if the grid-connected current of the wind power plant has the divergence trend, the attack is successful, otherwise, the attack current under the next attack mode is used for attacking again; if the attack currents in all the current attack modes are not attacked successfully, judging whether the state of the wind power plant and the operation state of the power grid change or not within a first preset time interval, and returning to the step of controlling the direct-hanging disturbance current injection device to inject a broadband current signal into the wind power grid-connected system and collect voltage and current signals at the grid-connected point when the state of the wind power plant or the operation state of the power grid changes until the attack is successful.
In one embodiment, the direct-hanging disturbance current injection device is composed of a flying capacitor type three-level topological structure and a single-phase H-bridge cascade sub-module power unit; the direct-hanging disturbance current injection device is controlled in the running state by a direct current total voltage control method and a current control method, a single-phase H-bridge cascade submodule is controlled by a voltage balance control method, and a flying capacitor type three-level topological structure is controlled by a direct current voltage control method.
In an embodiment, a process of controlling a direct-hanging disturbance current injection device to inject a broadband current signal into a grid-connected wind power system includes: obtaining a given broadband current signal based on a power spectrum of a random binary sequence and a preset multiple of a rated current of a direct-hanging type disturbance current injection device; superposing a given broadband current signal and a total voltage control output signal at a direct current side to be used as a current control reference value; after the current loop controller and modulation, the direct-hanging disturbance current injection device injects a broadband current signal into the wind power grid-connected system.
In an embodiment, the process of obtaining a system admittance-frequency characteristic curve based on collected voltage and current signals at a grid-connected point, identifying and obtaining an admittance-frequency characteristic expression of the system, and calculating the frequency and damping ratio of each mode of the system includes: carrying out spectrum analysis on the collected voltage and current signals at the grid-connected point to obtain a voltage phasor and a current phasor under each frequency component, and calculating a system admittance value under each frequency component; respectively connecting the real part and the imaginary part of the system admittance under each frequency component into a curve to obtain a system admittance-frequency characteristic curve; identifying the system admittance-frequency characteristic curve by adopting a transfer function identification method to obtain an admittance-frequency characteristic expression of the system; and setting the system admittance-frequency characteristic expression to be zero to obtain a plurality of zero points of the system admittance-frequency characteristic expression, and calculating the frequency and the damping ratio of each oscillation mode based on the zero points.
In an embodiment, the process of obtaining the attack current in each attack mode includes: taking the frequency of the current attack mode as the frequency of a given current disturbance signal; obtaining the amplitude of a given current disturbance signal according to the capacity of the direct-hanging disturbance current injection device and the admittance actual value of the current attack mode; obtaining a given sinusoidal current disturbance signal according to the frequency of the given current disturbance signal and the amplitude of the given current disturbance signal; superposing a given sinusoidal current disturbance signal and a direct-current side total voltage control output signal as a current loop reference value; after the current loop controller and modulation, the direct-hanging disturbance current injection device outputs attack current.
In one embodiment, the process of monitoring whether the grid-connected current of the wind power plant has a divergent trend includes: measuring a current signal at a grid-connected point in real time; acquiring current data of the previous second preset time interval at intervals of a second preset time interval, and calculating the damping ratio of the current signal with the frequency of the current attack mode; and in the attack current continuous attack preset time, if the damping ratio of the current signal with the frequency of the current attack mode is a negative value, determining that the grid-connected current of the wind power plant has a divergence trend.
In an embodiment, the process of determining whether the wind farm state and the grid operating state change within a first preset time interval includes: monitoring the wind speed in a first preset time interval, and judging that the state of the wind power plant changes when the change of the wind speed exceeds a preset multiple of a rated wind speed; and if the state of the wind power plant is not changed within the first preset time interval, judging that the running state of the power grid is changed.
In a second aspect, an embodiment of the present invention provides a wind farm attack apparatus, including: the acquisition module is used for installing the direct-hanging disturbance current injection device in parallel at a grid-connected point of a wind power plant, controlling the direct-hanging disturbance current injection device to inject a broadband current signal into a wind power grid-connected system and acquiring a voltage signal and a current signal at the grid-connected point; the calculation module is used for acquiring a system admittance-frequency characteristic curve based on the acquired voltage and current signals at the grid-connected point, identifying to obtain an admittance-frequency characteristic expression of the system, and calculating the frequency and damping ratio of each mode of the system; the sequencing module is used for setting the modes with the damping ratio smaller than a preset damping value as attack modes according to the frequency and the damping ratio of each mode of the system and sequencing the attack modes according to the damping ratio; the attack module is used for sequentially injecting attack current under each attack mode according to the order of the attack modes, each attack current continuously attacks for a preset time, whether the grid-connected current of the wind power plant has a divergence trend or not is monitored in the attack time of each attack current, if the grid-connected current of the wind power plant has the divergence trend, the attack is successful, and otherwise, the attack current under the next attack mode is used for attacking again; and the cyclic attack module is used for judging whether the state of the wind power plant and the operation state of the power grid change within a first preset time interval if the attack currents in all the current attack modes are not attacked successfully, and returning to the step of controlling the direct-hanging disturbance current injection device to inject a broadband current signal into the wind power grid-connected system and collecting the voltage and current signals at the grid-connected point when the state of the wind power plant or the operation state of the power grid changes until the attack is successful.
In a third aspect, an embodiment of the present invention provides a computer device, including: the wind farm attack system comprises at least one processor and a memory which is in communication connection with the at least one processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to cause the at least one processor to perform the wind farm attack method of the first aspect of the embodiment of the invention.
In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, where computer instructions are stored, and the computer instructions are used to cause a computer to execute the wind farm attack method according to the first aspect of the embodiment of the present invention.
The technical scheme of the invention has the following advantages:
according to the wind power plant attack method and system, the direct-hanging disturbance current injection device is installed at the grid-connected point of the wind power plant in parallel, and the direct-hanging disturbance current injection device is controlled to inject the broadband current signal into the wind power grid-connected system, so that the accuracy and efficiency of weak point identification of the wind power plant are improved; acquiring a system admittance-frequency characteristic curve and a system admittance-frequency characteristic expression based on voltage and current signals at a grid-connected point, and calculating the frequency and damping ratio of each mode of the system; selecting attack modes, and sequencing the attack modes according to the damping ratio; sequentially injecting attack current under each attack mode according to the order of the attack modes, wherein each attack current continuously attacks for a preset time, monitoring whether the grid-connected current of the wind power plant has a divergence trend within the attack time of each attack current, if the grid-connected current of the wind power plant has the divergence trend, the attack is successful, otherwise, the attack current under the next attack mode is used for attacking again; and if the attack currents in all the current attack modes are not attacked successfully, and when the state of the wind power plant or the operation state of the power grid changes, injecting the broadband current signal again, and selecting the attack mode to attack until the attack is successful. According to the method, the disturbance signals are directly injected at the physical side through the parallel disturbance device, so that the accuracy and efficiency of the weak point identification of the wind power plant are improved; the oscillation risk frequency existing in the system is effectively identified, effective information is provided for formulating a stability control strategy of the wind power plant, and the method can be used for testing the grid-connected stability of the wind power plant and verifying the small interference stability of the wind power plant after being connected to a large power grid.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a flowchart of a specific example of a method for attacking a wind farm according to an embodiment of the present invention;
fig. 2 is a structural diagram of a specific example of a direct-hanging disturbance current injection device according to an embodiment of the present invention;
FIG. 3 is a flowchart of another specific example of a method for attacking a wind farm according to an embodiment of the present invention;
FIG. 4 is a flowchart of another specific example of a method for attacking a wind farm according to an embodiment of the present invention;
FIG. 5 is a flowchart of another specific example of a method for attacking a wind farm according to an embodiment of the present invention;
FIG. 6 is a flowchart of another specific example of a method for attacking a wind farm according to an embodiment of the present invention;
FIG. 7 is a flowchart illustrating another specific example of a method for attacking a wind farm according to an embodiment of the present invention;
fig. 8 is a composition diagram of a specific example of a wind farm attack system according to an embodiment of the present invention;
fig. 9 is a block diagram of a specific example of a computer device according to an embodiment of the present invention.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; the two elements may be directly connected or indirectly connected through an intermediate medium, or may be communicated with each other inside the two elements, or may be wirelessly connected or wired connected. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
Example 1
The embodiment of the invention provides a wind power plant attack method, as shown in fig. 1, comprising the following steps:
step S11: the direct-hanging disturbance current injection device is installed at a grid-connected point of a wind power plant in parallel, the direct-hanging disturbance current injection device is controlled to inject a broadband current signal into a wind power grid-connected system, and voltage and current signals at the grid-connected point are collected.
The direct-hanging disturbance current injection device provided by the embodiment of the invention is not limited to the mature structure of the converter in the prior art, and the converter needs to inject a broadband current signal into a wind power grid-connected system, and is not limited herein. Specifically, the topological structure of the direct-hanging disturbance current injection device according to the embodiment of the present invention is shown in fig. 2, and the topological structure is composed of a Flying Capacitor (FC) type three-level topological structure and a single-phase H-bridge cascaded submodule power unit, where the number of H-bridge cascaded submodules per phase in fig. 2 is 4, but the present invention is only by way of example and is not limited thereto.
Specifically, the direct-hanging disturbance current injection device of the embodiment of the invention adopts double closed-loop control, namely, a direct-current total voltage control method and a current control method are utilized to control the running state of the direct-hanging disturbance current injection device, and in addition, a voltage balance control method is utilized to control a single-phase H-bridge cascade submodule and a direct-current voltage control method is utilized to control a flying capacitor type three-level topological structure.
Specifically, the H-bridge cascade sub-module of the embodiment of the invention adopts carrier phase shift modulation, and the FC three-level power unit adopts nearest level approximation modulation; the switching function of the FC three-level power unit and the modulation reference signal of the H-bridge cascade sub-module power unit have the following relation:
in the formula uchjrefIs the phase voltage u of the H-bridge cascade sub-module power unitjrefFor the output voltage reference value, S, of the direct-hanging disturbance current injection deviceFCjAs a switching function of the FC three-level power cell, udcIs the dc bus voltage of the FC three-level power cell.
It should be noted that the control method and the modulation method are mature methods in the prior art, and are not described herein again, and in addition, the embodiment of the present invention is not limited to the control method and the modulation method, and is not limited herein.
Specifically, as shown in fig. 3, the process of controlling the direct-hanging disturbance current injection device to inject the broadband current signal into the grid-connected wind power system is executed in steps S21 to S23, and specifically, the following steps are executed:
step S21: and obtaining a given broadband current signal based on the power spectrum of the random binary sequence and the preset multiple of the rated current of the direct-hanging disturbance current injection device.
Specifically, the power spectrum of the random binary sequence can be expressed as:
in the formula, q is the frequency number of the power spectrum, a is the signal amplitude, and N is the signal length.
And setting the amplitude of the given broadband current signal, wherein the value range is 1% -5% of the rated current of the system, and then obtaining the given broadband current signal according to the formula (2) and the amplitude.
Step S22: and superposing the given broadband current signal and the total voltage control output signal of the direct current side to be used as a current control reference value.
Step S23: after the current loop controller and modulation, the direct-hanging disturbance current injection device injects a broadband current signal into the wind power grid-connected system.
It should be noted that the direct-hanging disturbance current injection device according to the embodiment of the present invention needs to inject a broadband current signal into the grid-connected system, and the control method of the direct-hanging disturbance current injection device is the double closed-loop control, so that the broadband current signal needs to be obtained in step S22 and step S23, and if the direct-hanging disturbance current injection device adopts another control method, step S22 and step S23 may be adaptively transplanted.
Step S12: and acquiring a system admittance-frequency characteristic curve based on the acquired voltage and current signals at the grid-connected point, identifying to obtain an admittance-frequency characteristic expression of the system, and calculating the frequency and damping ratio of each mode of the system.
Specifically, in the embodiment of the present invention, in order to obtain the system oscillation mode under the injection of the broadband current signal, the voltage signal and the current signal need to be subjected to spectrum analysis, as shown in fig. 4, step S12 is executed by steps S31 to S34, as follows:
step S31: and carrying out spectrum analysis on the acquired voltage and current signals at the grid-connected point to obtain a voltage phasor and a current phasor under each frequency component, and calculating a system admittance value under each frequency component.
In the embodiment of the invention, the Fast Fourier Transform (FFT) is utilized to carry out spectrum analysis on the voltage and current signals obtained by sampling so as to obtain the voltage phasor under each frequency component
And current phasor
And calculates the system admittance value at each frequency component.
Step S32: and respectively connecting the real part and the imaginary part of the system admittance under each frequency component into a curve to obtain a system admittance-frequency characteristic curve.
Step S33: and identifying the system admittance-frequency characteristic curve by adopting a transfer function identification method to obtain an admittance-frequency characteristic expression of the system.
Specifically, a transfer function identification method is adopted to identify the system admittance-frequency characteristic curve, namely the following optimization problem is solved:
wherein Y (j ω) is an actual value of the system admittance-frequency characteristic, Yeq(j ω) is the identification of the system admittance-frequency characteristic.
Step S34: and setting the system admittance-frequency characteristic expression to be zero to obtain a plurality of zero points of the system admittance-frequency characteristic expression, and calculating the frequency and the damping ratio of each oscillation mode based on the zero points.
Specifically, let Yeq(s) < 0, calculating the zero point s of the system admittance-frequency characteristic expressioni＝αi±jωiAnd performing stability judgment according to the real part and the imaginary part of each zero point to obtain a plurality of oscillation modes. Calculating the frequency f of the oscillation mode according toiAnd damping ratio xii。
Step S13: and setting the modes with the damping ratios smaller than the preset damping value as attack modes according to the frequency and the damping ratio of each mode of the system, and sequencing the attack modes according to the damping ratios.
Specifically, the damping ratio is selected to be smaller than a preset damping value in all oscillation modesδAll oscillation modes of min are used as attack modes, and the number of the attack modes is N; the attack modes are sequenced according to the damping ratio, so that xi is1≤ξ2≤...≤ξ n ≤...≤ξN。
Step S14: according to the sequence of the attack modes, the attack current under each attack mode is injected in sequence, each attack current continuously attacks for a preset time, whether the grid-connected current of the wind power plant has a divergence trend or not is monitored within the attack time of each attack current, if the grid-connected current of the wind power plant has the divergence trend, the attack is successful, and otherwise, the attack current under the next attack mode is used for attacking again.
Specifically, assuming that there are three attack modes (attack mode # 1, attack mode # 2, attack mode # 3, ordered as attack mode # 1 → attack mode # 2 → attack mode #3) after the broadband current signal is currently injected and the voltage and current signals are collected, the attack is first performed by using the attack current # 1 under the attack mode # 1, in the process of attacking the attack current # 1, if the grid-connected current of the wind power plant has no divergence trend, the attack fails, and the attack current # 2 in the attack mode # 2 is used for attacking, in the process of attacking the attack current # 2, if the grid-connected current of the wind power plant has no divergence trend, the attack fails, and the attack current # 3 in the attack mode # 3 is used for attacking, in the process of attacking the attack current # 3, if the grid-connected current of the wind power plant does not have a divergence trend, the attack fails.
Specifically, as shown in fig. 5, the process of obtaining the attack current in each attack mode includes steps 41 to 45, as follows:
step S41: and taking the frequency of the current attack mode as the frequency of the given current disturbance signal.
Step S42: and obtaining the amplitude of the given current disturbance signal according to the capacity of the direct-hanging disturbance current injection device and the admittance actual value of the current attack mode.
Specifically, according to a system admittance-frequency characteristic curve, obtaining an admittance actual value of a current attack mode, and calculating an amplitude of a given current disturbance signal according to the following formula:
in the formula, SmaxThe maximum output capacity of the direct-hanging disturbance current injection device is obtained.
Step S43: and obtaining a given sinusoidal current disturbance signal according to the frequency of the given current disturbance signal and the amplitude of the given current disturbance signal.
Step S44: and superposing the given sinusoidal current disturbance signal and the total voltage control output signal of the direct current side as a current loop reference value.
Step S45: after the current loop controller and modulation, the direct-hanging disturbance current injection device outputs attack current.
Specifically, after the attack current continues to attack for a preset time, the amplitude of the given sinusoidal current perturbation signal is set to zero.
It should be noted that the direct-hanging disturbance current injection device according to the embodiment of the present invention needs to inject an attack current into the grid-connected system of the wind power plant, and the control method of the direct-hanging disturbance current injection device is the double closed loop control, so that the attack current needs to be obtained in step S44 and step S45, and if the direct-hanging disturbance current injection device adopts another control method, step S44 and step S45 may be adaptively transplanted.
Specifically, as shown in fig. 6, the process of monitoring whether the grid-connected current of the wind farm has a divergence trend includes steps S51 to S53, as follows:
step S51: and measuring a current signal at a grid-connected point in real time.
Step S52: and acquiring current data of the previous second preset time interval every second preset time interval, and calculating the damping ratio of the current signal with the frequency of the current attack mode.
Specifically, in the process of attacking the attack current every time and within the preset time of continuous attack of the attack current, current data within the previous time delta t is taken every second preset time interval delta t, and a Prony algorithm is adopted to calculate the frequency f in the current signaliCurrent signal damping ratio.
Step S53: and in the attack current continuous attack preset time, if the damping ratio of the current signal with the frequency of the current attack mode is a negative value, determining that the grid-connected current of the wind power plant has a divergence trend.
Step S15: if the attack currents in all the current attack modes are not attacked successfully, judging whether the state of the wind power plant and the operation state of the power grid change or not within a first preset time interval, and returning to the step of controlling the direct-hanging disturbance current injection device to inject a broadband current signal into the wind power grid-connected system and collect voltage and current signals at the grid-connected point when the state of the wind power plant or the operation state of the power grid changes until the attack is successful.
Specifically, it is assumed that after the broadband current signal is injected currently and the voltage and current signals are acquired, there are three attack modes, if attack currents in the three attack modes fail to attack, it is possible that the wind farm state and the power grid operating state change, and when one of the attack currents changes, the broadband current signal is injected again, the attack mode and the attack current are selected again, and attack is performed again.
Specifically, as shown in fig. 7, the process of determining whether the wind farm state and the grid operating state change within the first preset time interval includes steps S61 to S62, as follows:
step S61: and monitoring the wind speed in a first preset time interval, and judging that the state of the wind power plant changes when the change of the wind speed exceeds a preset multiple of the rated wind speed.
Step S62: and if the state of the wind power plant is not changed within the first preset time interval, judging that the running state of the power grid is changed.
Specifically, if the wind speed change does not exceed a preset multiple of the rated wind speed within a first preset time interval, the power grid operation state is determined to be changed.
Example 2
An embodiment of the present invention provides a wind farm attack apparatus, as shown in fig. 8, including:
the acquisition module 1 is used for installing the direct-hanging disturbance current injection device in parallel at a grid-connected point of a wind power plant, controlling the direct-hanging disturbance current injection device to inject a broadband current signal into a wind power grid-connected system, and acquiring voltage and current signals at the grid-connected point; this module executes the method described in step S11 in embodiment 1, and is not described herein again.
The calculation module 2 is used for acquiring a system admittance-frequency characteristic curve based on the acquired voltage and current signals at the grid-connected point, identifying to obtain an admittance-frequency characteristic expression of the system, and calculating the frequency and damping ratio of each mode of the system; this module executes the method described in step S12 in embodiment 1, and is not described herein again.
The sequencing module 3 is used for setting the modes with the damping ratio smaller than a preset damping value as attack modes according to the frequency and the damping ratio of each mode of the system and sequencing the attack modes according to the damping ratio; this module executes the method described in step S13 in embodiment 1, and is not described herein again.
The attack module 4 is used for sequentially injecting attack current under each attack mode according to the order of the attack modes, wherein each attack current continuously attacks for a preset time, and monitoring whether the grid-connected current of the wind power plant has a divergence trend within the attack time of each attack current, if the grid-connected current of the wind power plant has the divergence trend, the attack is successful, otherwise, the attack current under the next attack mode is used for attacking again; this module executes the method described in step S13 in embodiment 1, and is not described herein again.
The cyclic attack module 5 is used for judging whether the state of the wind power plant and the operation state of the power grid change within a first preset time interval if attack currents in all current attack modes are not attacked successfully, and returning to the step of controlling the direct-hanging disturbance current injection device to inject a broadband current signal into the wind power grid-connected system and collecting a voltage signal and a current signal at a grid-connected point when the state of the wind power plant or the operation state of the power grid changes until the attack is successful; this module executes the method described in step S14 in embodiment 1, and is not described herein again.
Example 3
An embodiment of the present invention provides a computer device, as shown in fig. 9, including: at least one processor 401, such as a CPU (Central Processing Unit), at least one communication interface 403, memory 404, and at least one communication bus 402. Wherein a communication bus 402 is used to enable connective communication between these components. The communication interface 403 may include a Display (Display) and a Keyboard (Keyboard), and the optional communication interface 403 may also include a standard wired interface and a standard wireless interface. The Memory 404 may be a RAM (random Access Memory) or a non-volatile Memory (non-volatile Memory), such as at least one disk Memory. The memory 404 may optionally be at least one memory device located remotely from the processor 401. Wherein processor 401 may execute the wind farm attack method of embodiment 1. A set of program codes is stored in the memory 404 and the processor 401 invokes the program codes stored in the memory 404 for performing the wind farm attack method of embodiment 1.
The communication bus 402 may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The communication bus 402 may be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one line is shown in FIG. 9, but this does not represent only one bus or one type of bus.
The memory 404 may include a volatile memory (RAM), such as a random-access memory (RAM); the memory may also include a non-volatile memory (english: non-volatile memory), such as a flash memory (english: flash memory), a hard disk (english: hard disk drive, abbreviated: HDD) or a solid-state drive (english: SSD); the memory 404 may also comprise a combination of memories of the kind described above.
The processor 401 may be a Central Processing Unit (CPU), a Network Processor (NP), or a combination of a CPU and an NP.
The processor 401 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a Programmable Logic Device (PLD), or a combination thereof. The PLD may be a Complex Programmable Logic Device (CPLD), a field-programmable gate array (FPGA), a General Array Logic (GAL), or any combination thereof.
Optionally, the memory 404 is also used to store program instructions. Processor 401 may invoke program instructions to implement the wind farm attack method of embodiment 1 as implemented herein.
The embodiment of the invention also provides a computer-readable storage medium, wherein a computer-executable instruction is stored on the computer-readable storage medium, and the computer-executable instruction can execute the wind power plant attack method of the embodiment 1. The storage medium may be a magnetic Disk, an optical Disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a Flash Memory (Flash Memory), a Hard Disk (Hard Disk Drive, abbreviated as HDD), a Solid-State Drive (SSD), or the like; the storage medium may also comprise a combination of memories of the kind described above.
It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of the invention may be made without departing from the spirit or scope of the invention.
Claims (10)
1. A wind farm attack method is characterized by comprising the following steps:
the method comprises the following steps that a direct-hanging disturbance current injection device is installed at a grid-connected point of a wind power plant in parallel, the direct-hanging disturbance current injection device is controlled to inject a broadband current signal into a wind power grid-connected system, and voltage and current signals at the grid-connected point are collected;
acquiring a system admittance-frequency characteristic curve based on the acquired voltage and current signals at the grid-connected point, identifying to obtain an admittance-frequency characteristic expression of the system, and calculating the frequency and damping ratio of each mode of the system;
setting the modes with the damping ratio smaller than a preset damping value as attack modes according to the frequency and the damping ratio of each mode of the system, and sequencing the attack modes according to the damping ratio;
according to the sequence of the attack modes, sequentially injecting attack current under each attack mode, wherein each attack current continuously attacks for a preset time, monitoring whether the grid-connected current of the wind power plant has a divergence trend within the attack time of each attack current, if the grid-connected current of the wind power plant has the divergence trend, the attack is successful, otherwise, the attack current under the next attack mode is used for attacking again;
if the attack currents in all the current attack modes are not attacked successfully, judging whether the state of the wind power plant and the operation state of the power grid change or not within a first preset time interval, and returning to the step of controlling the direct-hanging disturbance current injection device to inject a broadband current signal into the wind power grid-connected system and collect voltage and current signals at the grid-connected point when the state of the wind power plant or the operation state of the power grid changes until the attack is successful.
2. The wind farm attack method according to claim 1,
the direct-hanging disturbance current injection device is composed of a flying capacitor type three-level topological structure and a single-phase H-bridge cascade sub-module power unit;
the direct-hanging disturbance current injection device is controlled to operate by a direct current total voltage control method and a current control method, the single-phase H-bridge cascade sub-module is controlled by a voltage balance control method, and the flying capacitor type three-level topological structure is controlled by a direct current voltage control method.
3. The wind farm attack method according to claim 2, wherein the process of controlling the direct-hanging disturbance current injection device to inject the broadband current signal into the wind power grid-connected system comprises:
obtaining a given broadband current signal based on a power spectrum of a random binary sequence and a preset multiple of a rated current of a direct-hanging type disturbance current injection device;
superposing a given broadband current signal and a total voltage control output signal at a direct current side to be used as a current control reference value;
after the current loop controller and modulation, the direct-hanging disturbance current injection device injects a broadband current signal into the wind power grid-connected system.
4. The wind farm attack method according to claim 1, wherein the process of obtaining a system admittance-frequency characteristic curve based on the collected voltage and current signals at the grid-connected point, identifying and obtaining an admittance-frequency characteristic expression of the system, and calculating the frequency and damping ratio of each mode of the system comprises:
carrying out spectrum analysis on the collected voltage and current signals at the grid-connected point to obtain a voltage phasor and a current phasor under each frequency component, and calculating a system admittance value under each frequency component;
respectively connecting the real part and the imaginary part of the system admittance under each frequency component into a curve to obtain a system admittance-frequency characteristic curve;
identifying the system admittance-frequency characteristic curve by adopting a transfer function identification method to obtain an admittance-frequency characteristic expression of the system;
and setting the system admittance-frequency characteristic expression to be zero to obtain a plurality of zero points of the system admittance-frequency characteristic expression, and calculating the frequency and the damping ratio of each oscillation mode based on the zero points.
5. A wind farm attack method according to claim 4, wherein the process of deriving the attack current in each attack mode comprises:
taking the frequency of the current attack mode as the frequency of a given current disturbance signal;
obtaining the amplitude of a given current disturbance signal according to the capacity of the direct-hanging disturbance current injection device and the admittance actual value of the current attack mode;
obtaining a given sinusoidal current disturbance signal according to the frequency of the given current disturbance signal and the amplitude of the given current disturbance signal;
superposing a given sinusoidal current disturbance signal and a direct-current side total voltage control output signal as a current loop reference value;
after the current loop controller and modulation, the direct-hanging disturbance current injection device outputs attack current.
6. The wind farm attack method according to claim 1, wherein the process of monitoring whether the wind farm grid-connected current has a divergent trend comprises:
measuring a current signal at a grid-connected point in real time;
acquiring current data of the previous second preset time interval at intervals of a second preset time interval, and calculating the damping ratio of the current signal with the frequency of the current attack mode;
and in the attack current continuous attack preset time, if the damping ratio of the current signal with the frequency of the current attack mode is a negative value, determining that the grid-connected current of the wind power plant has a divergence trend.
7. The wind farm attack method according to claim 1, wherein the process of determining whether the wind farm state and the grid operating state change within a first preset time interval comprises:
monitoring the wind speed in a first preset time interval, and judging that the state of the wind power plant changes when the change of the wind speed exceeds a preset multiple of a rated wind speed;
and if the state of the wind power plant is not changed within the first preset time interval, judging that the running state of the power grid is changed.
8. A wind farm attack apparatus, comprising:
the acquisition module is used for installing the direct-hanging disturbance current injection device in parallel at a grid-connected point of a wind power plant, controlling the direct-hanging disturbance current injection device to inject a broadband current signal into a wind power grid-connected system and acquiring a voltage signal and a current signal at the grid-connected point;
the calculation module is used for acquiring a system admittance-frequency characteristic curve based on the acquired voltage and current signals at the grid-connected point, identifying to obtain an admittance-frequency characteristic expression of the system, and calculating the frequency and damping ratio of each mode of the system;
the sequencing module is used for setting the modes with the damping ratio smaller than a preset damping value as attack modes according to the frequency and the damping ratio of each mode of the system and sequencing the attack modes according to the damping ratio;
the attack module is used for sequentially injecting attack current under each attack mode according to the order of the attack modes, each attack current continuously attacks for a preset time, whether the grid-connected current of the wind power plant has a divergence trend or not is monitored in the attack time of each attack current, if the grid-connected current of the wind power plant has the divergence trend, the attack is successful, and otherwise, the attack current under the next attack mode is used for attacking again;
and the cyclic attack module is used for judging whether the state of the wind power plant and the operation state of the power grid change within a first preset time interval if the attack currents in all the current attack modes are not attacked successfully, and returning to the step of controlling the direct-hanging disturbance current injection device to inject the broadband current signal into the wind power grid-connected system and collect the voltage and current signals at the grid-connected point when the state of the wind power plant or the operation state of the power grid changes until the attack is successful.
9. A computer device, comprising: at least one processor, and a memory communicatively coupled to the at least one processor, wherein the memory stores instructions executable by the at least one processor to cause the at least one processor to perform the wind farm attack method of any one of claims 1-7.
10. A computer-readable storage medium having stored thereon computer instructions for causing a computer to execute the wind farm attack method of any one of claims 1-7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210029825.0A CN114362245B (en) | 2022-01-12 | 2022-01-12 | Wind farm attack method and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210029825.0A CN114362245B (en) | 2022-01-12 | 2022-01-12 | Wind farm attack method and system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114362245A true CN114362245A (en) | 2022-04-15 |
| CN114362245B CN114362245B (en) | 2023-09-08 |
Family
ID=81109822
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210029825.0A Active CN114362245B (en) | 2022-01-12 | 2022-01-12 | Wind farm attack method and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114362245B (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101408567A (en) * | 2008-11-28 | 2009-04-15 | 北京四方继保自动化股份有限公司 | Large scale electric network low-frequency oscillation frequency division section detection method based on empirical mode decomposition |
| US20090099798A1 (en) * | 2007-10-09 | 2009-04-16 | Yanfeng Gong | Real-Time Power System Oscillation Detection Using Modal Analysis |
| CN101630273A (en) * | 2009-08-06 | 2010-01-20 | 中国电力科学研究院 | Small interference stability simulation method of electric power system |
| CN102122824A (en) * | 2011-04-11 | 2011-07-13 | 武汉大学 | Method and device for identifying low-frequency oscillation mode parameters of power system |
| CN102170126A (en) * | 2011-04-06 | 2011-08-31 | 华中电网有限公司 | Online analysis and early warning method for low-frequency oscillation of electric power system |
| CN111384717A (en) * | 2020-01-15 | 2020-07-07 | 华中科技大学 | Adaptive damping control method and system for resisting false data injection attack |
| CN112365115A (en) * | 2020-08-26 | 2021-02-12 | 天津大学 | Power grid information energy system stability assessment method |
-
2022
- 2022-01-12 CN CN202210029825.0A patent/CN114362245B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090099798A1 (en) * | 2007-10-09 | 2009-04-16 | Yanfeng Gong | Real-Time Power System Oscillation Detection Using Modal Analysis |
| CN101408567A (en) * | 2008-11-28 | 2009-04-15 | 北京四方继保自动化股份有限公司 | Large scale electric network low-frequency oscillation frequency division section detection method based on empirical mode decomposition |
| CN101630273A (en) * | 2009-08-06 | 2010-01-20 | 中国电力科学研究院 | Small interference stability simulation method of electric power system |
| CN102170126A (en) * | 2011-04-06 | 2011-08-31 | 华中电网有限公司 | Online analysis and early warning method for low-frequency oscillation of electric power system |
| CN102122824A (en) * | 2011-04-11 | 2011-07-13 | 武汉大学 | Method and device for identifying low-frequency oscillation mode parameters of power system |
| CN111384717A (en) * | 2020-01-15 | 2020-07-07 | 华中科技大学 | Adaptive damping control method and system for resisting false data injection attack |
| CN112365115A (en) * | 2020-08-26 | 2021-02-12 | 天津大学 | Power grid information energy system stability assessment method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114362245B (en) | 2023-09-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111368449B (en) | Cascading failure evolution path online identification method considering alternating current and direct current influences | |
| CN113285471B (en) | Offshore wind farm subsynchronous oscillation source sensing and positioning method, device and equipment | |
| CN107766596B (en) | Low-voltage ride-through capability simulation evaluation method based on typical fault working condition set | |
| CN114123344A (en) | Power system inertia evaluation method and device based on adaptive recursive least squares | |
| CN108009063A (en) | The method of a kind of electronic equipment fault threshold detection | |
| Jarrahi et al. | Fault detection in DC microgrid: A transient monitoring function-based method | |
| CN118311376A (en) | Fault line selection method and device for power distribution network, medium and equipment | |
| Kulkarni et al. | Enhancing grid resiliency in distributed energy systems through a comprehensive review and comparative analysis of islanding detection methods | |
| CN114362245A (en) | Wind power plant attack method and system | |
| CN117096848A (en) | Virtual synchronous generator high-current prediction method, system, terminal and storage medium | |
| CN114389241B (en) | Relay protection setting value setting method and device for active power distribution network | |
| CN115407142A (en) | Multi-inverter island detection method for photovoltaic power generation system based on wavelet transformation | |
| CN114784800A (en) | Method and system for analyzing resonance stability of power distribution network | |
| Stanisavljević et al. | A method for real-time prediction of the probability of voltage sag duration based on harmonic footprint | |
| CN113872197A (en) | Method and device for predicting power quality interference source acceptance capacity | |
| Zarei et al. | Predictive control of a permanent magnet synchronous generator connected to an MMC converter in an oscillating water column based power plant | |
| CN117477642B (en) | Asymmetric fault ride-through control method and device for multiple wind power plants and electronic equipment | |
| CN116093979B (en) | Wind power station frequency support control method and system based on PCC-COI frequency | |
| CN117543518B (en) | Transient overvoltage control system and method | |
| CN114123164B (en) | Method and device for calculating short-circuit capacity of power system and terminal equipment | |
| CN110601251B (en) | Voltage prediction method and device in wind power plant | |
| CN115248358A (en) | Fault detection method and device for cascade energy storage system | |
| CN115940196A (en) | Method for inhibiting subsynchronous resonance of power system | |
| CN108535564B (en) | Control method for rapid bypass series compensation equipment of high-voltage direct current system | |
| CN116522588A (en) | Photovoltaic grid-connected system fault analysis method based on coordinate transformation and cluster analysis |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |