Power system load frequency control method based on high-order all-drive system theory

Abstract

The invention provides a power system load frequency control method based on a high-order all-drive system theory, and relates to the technical field of power system load frequency control. Comprising the following steps: collecting physical parameters of a power system, and establishing a power system state space equation mathematical model according to the physical parameters of the power system; verifying the controllability of the power system according to the state-space equation model, and obtaining a system controllability matrix; based on the controllability matrix, converting a state-space equation model of the power system into a high-order all-drive system model; providing a power system state observer and a spoofing attack observer according to the high-order all-drive system model; and providing a power system load frequency controller based on a high-order all-drive system theory according to the high-order all-drive system model and the observer. According to the method, the linear dynamic model of the electric power system more conforming to actual working conditions is constructed. Based on the high-order all-drive method, the design complexity of the power system controller can be reduced, and the stability of the power system is ensured.

Description

A Power System Load Frequency Control Method Based on High-Order All-Drive System Theory Technical Field

[0001] This invention relates to the technical field of power system load frequency control, and more particularly to a power system load frequency control method based on high-order all-drive system theory. Background Technology

[0002] As a crucial pillar of national development, the power system plays a vital role in daily life and industry. Frequency is a key indicator of power quality in power system operation. Frequency fluctuations can impact the normal operation of the power system and even jeopardize its overall safety. Load frequency is a crucial means of maintaining the power system's load frequency within an acceptable range. It detects deviations in the grid frequency and uses these deviations to achieve stable control of the power system's load frequency, thereby ensuring the stable operation of the power system.

[0003] In actual operation, the interconnected nature of power systems leads to increasing openness, making them constantly vulnerable to severe cyberattacks. Among these, deception attacks are a frequent and highly covert method of cybersecurity in power systems. Their core danger lies in breaching system defenses by forging data and altering commands. Without effective countermeasures, such attacks could lead to the hijacking of the power system and ultimately cause a complete network outage. Therefore, designing reasonable defense strategies to ensure the stable and safe operation of power systems in a cyberattack environment has become a focus of attention for both academia and industry.

[0004] On the other hand, traditional load frequency control methods require solving linear matrix inequalities during the design process, which is complex and computationally expensive. In contrast, the high-order all-drive system method transforms the system into a high-order all-drive form, and then the controller design can be completed with simple pole placement, greatly simplifying the calculation process and improving design efficiency. Therefore, introducing the high-order all-drive system method into the design of power system load frequency control has important theoretical and applied value for optimizing control strategy design. Summary of the Invention

[0005] To address the technical problems mentioned in the background section, this invention provides a power system load frequency control method based on high-order full-drive system theory. First, the physical parameters of the power system are collected to establish a dynamic mathematical model of the power system. Then, based on the state-space equation model, the controllability of the power system is verified, and the controllability matrix of the system is obtained. Further, based on the controllability matrix, the power system state-space equation model is converted into a high-order full-drive system model. Subsequently, based on the high-order full-drive system model, a power system state observer and a spoofing attack observer are provided. Finally, based on the high-order full-drive system model and high-order full-drive system theory, a power system load frequency controller is provided.

[0006] The technical means adopted in this invention are as follows: A power system load frequency control method based on high-order full-drive system theory, comprising the following steps: S1, collecting the physical parameters of the power system, and establishing a power system state-space equation mathematical model based on the physical parameters of the power system; S2, verifying the controllability of the power system based on the state-space equation model, and obtaining the system controllability matrix; S3, converting the power system state-space equation model into a high-order full-drive system model based on the controllability matrix; S4, providing a power system state observer and a deception attack observer based on the high-order full-drive system model; S5, providing a power system load frequency controller based on the high-order full-drive system model and the observer, and using high-order full-drive system theory.

[0007] Furthermore, the power system state-space equation model established in S1 is as follows: ; ;in ; Represents the frequency offset function; Indicates the governor value position. Indicates the turbine's output power; Indicates the incremental change in electric vehicles; Indicates regional control error; Indicates the controller input signal; This indicates a deception attack that the system has suffered; This indicates external disturbances to the system; Indicates system output; matrix , , As shown below: ; ; ; ;in, Indicates the load damping coefficient; Represents the inertia constant; This indicates the droop characteristic of the speed controller; Represents the governor constant; Indicates the turbine time constant; This indicates the sag characteristic of electric vehicles; , These are respectively represented as the electric vehicle participation factor and the electric vehicle thermal turbine coefficient; , These represent the electric vehicle gain and the electric vehicle time constant, respectively. Represents the frequency offset constant; the deception attack The model is as follows:

[0008] in, Denotes the coefficients of the deception attack system, satisfying .

[0009] Furthermore, S2 includes the following steps: determining the following controllability matrix. The singularity of S1 is used to verify the controllability of the power system in S1. ;in, and The system matrix is ​​given in S1; if the controllability matrix is... If it is not singular, then the power system is controllable.

[0010] Further, S3 includes the following steps: S31, Write the following characteristic polynomial based on the power system state-space equation model: S32. Obtain the following matrix through the characteristic polynomial: S33. Perform a non-singular transformation: ;in, , S2 is the system controllability matrix; S34, based on the non-singular transformation in S33, the power system state-space equation model is transformed into the following controllable canonical form: ;in, For the state variables in the standard form of power system energy control, ; ; S35. According to the power system energy control standard type in S34, let... The state-space equation model of the power system in S1 can be transformed into the following high-order all-drive system model: ;in, ; ; ; For integers , and They represent and of First derivative; S36, based on the power system energy control standard form in S34 and We can obtain: ;in, According to the non-singular transformation in S33, the control output of the original power system can be converted into a higher-order all-drive model: .

[0011] Furthermore, S4 includes the following steps: S41, based on the theory of high-order full-drive systems, the state observer and the deception attack observer of the power system take the following forms: ;in, ; Represents the state observation value, express The derivative; Observations representing deception attack signals; Represents auxiliary variables. express The derivative; S42, Solve for the observer gain. (This section represents the state observer gain and the attack signal observer gain, respectively.) and .

[0012] Further, S42 includes the following steps: S421, for solving... and First, we need to solve for the matrix that satisfies the following conditions. and : ;in ;in, ; ; Represents positive real numbers; Represents the identity matrix; Given by S41; This represents the output matrix of the original power system; This is the correlation matrix of the deception attack model in S1; This is the non-singular transformation matrix in S33; Given by S35; Given by S36; S422, solved by the following formula and : ; .

[0013] Furthermore, in S5, based on the theory of high-order all-drive systems, the power system load frequency controller is: ;in, This represents the desired pole of the closed-loop power system, and its value can be determined based on the specific performance indicators of the power system load frequency control required by the user.

[0014] Compared with existing technologies, this invention has the following advantages: The method of this invention considers the interference characteristics of deception attacks and constructs a linear dynamic model of the power system that better reflects actual operating conditions. Based on the given state transformation of the controllable-high-order full-drive system, the power system dynamic model is transformed into a high-order full-drive system; and based on the theory of high-order full-drive systems, a power system load frequency control scheme is designed. This scheme can directly transform the closed-loop system into a linear time-invariant high-order system, and allows for arbitrary configuration of the coefficients of the closed-loop characteristic polynomial. In contrast, traditional state-space equation methods require matrix operations to solve for feedback gain, which is somewhat indirect. In summary, the method provided by this invention makes controller design more intuitive, effectively reduces computational complexity, and improves the engineering practicality of the control scheme. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 is a schematic block diagram of the present invention.

[0017] Figure 2 shows the observation error curve of the deception attack.

[0018] Figure 3 shows the system state observation error curve.

[0019] Figure 4 shows the system state response curves under a high-order all-drive system.

[0020] Figure 5 shows the system state response curve under the original system. Detailed Implementation

[0021] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0022] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0023] As shown in Figure 1, this invention provides a power system load frequency control method based on high-order full-drive system theory. Considering a power system, it is converted into a high-order full-drive system model, and a feedback controller is designed. The method includes the following steps executed by a computer: S1. Collecting the physical parameters of the power system and establishing a mathematical model of the power system's state-space equations based on these parameters; S2. Verifying the controllability of the power system based on the state-space equation model and obtaining a system controllability matrix; S3. Based on the controllability matrix, converting the power system's state-space equation model into a high-order full-drive system model; S4. Providing a power system state observer and a deception attack observer based on the high-order full-drive system model; S5. Based on the high-order full-drive system model and the observer, providing a power system load frequency controller based on high-order full-drive system theory.

[0024] Preferably, the power system state-space equation model established in step S1 is as follows: ; ;in ; Represents the frequency offset function; Indicates the governor value position. Indicates the turbine's output power; Indicates the incremental change in electric vehicles; Indicates regional control error; Indicates the controller input signal; This indicates a deception attack that the system has suffered; This indicates external disturbances to the system; Indicates system output; matrix , , and As shown below: ; ; ; ;in, Indicates the load damping coefficient; Represents the inertia constant; This indicates the droop characteristic of the speed controller; Represents the governor constant; Indicates the turbine time constant; This indicates the sag characteristic of electric vehicles; , These are respectively represented as the electric vehicle participation factor and the electric vehicle thermal turbine coefficient; , These represent the electric vehicle gain and the electric vehicle time constant, respectively. This represents the frequency offset constant.

[0025] The deception attack The model is as follows:

[0026] in The coefficient of the deception attack system. .

[0027] Preferably, step S2 specifically includes the following steps: determining the following controllability matrix. The singularity of S1 is used to verify the controllability of the power system in S1. ;in, and The system matrix is ​​given in S1. If the controllability matrix... If it is not singular, then the power system is controllable.

[0028] Preferably, step S3 specifically includes the following steps: S31, Write the following characteristic polynomial based on the power system state-space equation model: S32. Obtain the following matrix through the characteristic polynomial: S33. Perform a non-singular transformation: ;in, , S2 is the system controllability matrix; S34, based on the non-singular transformation in S33, the power system state-space equation model is transformed into the following controllable canonical form: ;in, For the state variables in the standard form of power system energy control, ; ; S35. According to the power system energy control standard type in S34, let... The state-space equation model of the power system in S1 can be transformed into the following high-order all-drive system model: ;in, ; ; ; .

[0029] For integers , and They represent and of The first derivative.

[0030] S36, Based on the power system energy control standard type in S34 and We can obtain: ;in, .

[0031] Based on the nonsingular transformation in S33, the control output of the original power system can be converted into the following high-order all-drive model: .

[0032] Preferably, step S4 specifically includes the following steps: S41, based on the theory of high-order full-drive systems, the state observer and deception attack observer of the power system take the following forms: ;in ; These are state observations. yes The derivative; These are observations of deception attack signals; It is an auxiliary variable. yes The derivative; These are the state observer gain and the attack signal observer gain, respectively.

[0033] S42, Solve for observer gain and

[0034] S421, To solve and First, we need to solve for the matrix that satisfies the following conditions. and : ;in

[0035] in ; ; It is a positive real number; It is the identity matrix; Given by S41; This is the output matrix of the original power system; This is the correlation matrix of the deception attack model in S1; This is the non-singular transformation matrix in S33; Given by S35; Given by S36.

[0036] S422, Solve using the following formula and : ; .

[0037] Preferably, the controller provided in step S5 is in the following form: ;in, This represents the desired pole of the closed-loop power system, and its value can be determined based on the specific performance indicators of the power system load frequency control required by the user.

[0038] Example: Select the following observer gain ; and controller gain Figure 2 shows the system state curves under the high-order all-drive system after the designed load frequency controller is applied to the system. Figure 3 shows the system state curves under the original system. It can be seen that the load frequency controller designed in this invention can ensure the stability of the power system.

[0039] Table 1 Power System Simulation Parameter Table

[0040] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. In the above embodiments of the present invention, the descriptions of each embodiment have their own emphasis; parts not described in detail in a certain embodiment can be referred to in the relevant descriptions of other embodiments. It should be understood that the disclosed technical content in the several embodiments provided in this application can be implemented in other ways.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention 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 or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A power system load frequency control method based on high-order all-drive system theory, characterized in that, Includes the following steps: S1. Collect the physical parameters of the power system and establish a mathematical model of the state-space equations of the power system based on the physical parameters of the power system; S2. Verify the controllability of the power system based on the state-space equation model and obtain the system controllability matrix; S3. Based on the controllability matrix, convert the power system state-space equation model into a high-order full-drive system model; S4. Based on the high-order full-drive system model, provide a power system state observer and a deception attack observer; S5. Based on the high-order full-drive system model and the observer, provide a power system load frequency controller based on high-order full-drive system theory.

2. The power system load frequency control method based on high-order all-drive system theory according to claim 1, characterized in that, The state-space equation model of the power system established in S1 is as follows: ； ;in ； Represents the frequency offset function; Indicates the governor value position. Indicates the turbine's output power; Indicates the incremental change in electric vehicles; Indicates regional control error; Indicates the controller input signal; This indicates a deception attack that the system has suffered; This indicates external disturbances to the system; Indicates system output; matrix ， ， As shown below: ； ； ； ;in, Indicates the load damping coefficient; Represents the inertia constant; This indicates the droop characteristic of the speed controller; Represents the governor constant; Indicates the turbine time constant; This indicates the sag characteristic of electric vehicles; ， These are respectively represented as the electric vehicle participation factor and the electric vehicle thermal turbine coefficient; ， These represent the electric vehicle gain and the electric vehicle time constant, respectively. Represents the frequency offset constant; the deception attack The model is as follows: in, Denotes the coefficients of the deception attack system, satisfying 。 3. The power system load frequency control method based on high-order all-drive system theory according to claim 1, characterized in that, S2 includes the following steps: determining the following controllability matrix The singularity of S1 is used to verify the controllability of the power system in S1. ;in, and The system matrix is ​​given in S1; if the controllability matrix is... If it is not singular, then the power system is controllable.

4. The power system load frequency control method based on high-order all-drive system theory according to claim 1, characterized in that, The S3 The steps include: S31. Based on the state-space equation model of the power system, write the following characteristic polynomial: S32. Obtain the following matrix through the characteristic polynomial: S33. Perform a non-singular transformation: ;in, ， S2 is the system controllability matrix; S34, based on the non-singular transformation in S33, the power system state-space equation model is transformed into the following controllable canonical form: ;in, For the state variables in the standard form of power system energy control, ； ； S35. According to the power system energy control standard type in S34, let... The state-space equation model of the power system in S1 can be transformed into the following high-order all-drive system model: ;in, ； ； ； For integers ， and They represent and of First derivative; S36, based on the power system energy control standard form in S34 and We can obtain: ;in, According to the non-singular transformation in S33, the control output of the original power system can be converted into a higher-order all-drive model: 。 5. The power system load frequency control method based on high-order all-drive system theory according to claim 1, characterized in that, S4 includes the following steps: S41, Based on the high-order full-drive system theory, the state observer and deception attack observer of the power system are in the following form: ;in, ； Represents the state observation value, express The derivative; Observations representing deception attack signals; Represents auxiliary variables. express The derivative; S42, Solve for the observer gain. (This section represents the state observer gain and the attack signal observer gain, respectively.) and 。 6. The power system load frequency control method based on high-order all-drive system theory according to claim 1, characterized in that, S42 includes the following steps: S421, for solving... and First, we need to solve for the matrix that satisfies the following conditions. and ： ;in ;in, ； ； Represents positive real numbers; Represents the identity matrix; Given by S41; This represents the output matrix of the original power system; This is the correlation matrix of the deception attack model in S1; This is the non-singular transformation matrix in S33; Given by S35; Given by S36; S422, solved by the following formula and ： ； 。 7. The power system load frequency control method based on high-order all-drive system theory according to claim 1, characterized in that, In S5, based on the theory of high-order all-drive systems, the power system load frequency controller is: ;in, This represents the desired pole of the closed-loop power system, and its value can be determined based on the specific performance indicators of the power system load frequency control required by the user.

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