Water turbine speed regulation system simulation modeling method based on passive control

Abstract

A water turbine speed regulation system simulation modeling method based on passive control is used for generating an accurate and simple model with more physical meanings through modeling, simulation, control, regulation and analysis comparison under the condition that system dynamics is not separated and system physical characteristics are not ignored, and a natural structure of a water turbine speed regulation system is used for establishing a simulation model for a water turbine speed regulation system. And obtaining a Hamiltonian model of the system. A port Hamiltonian model is constructed to accurately describe the dynamic behavior of the water turbine speed regulation system, and a control strategy capable of ensuring the global asymptotic stability of the system is designed on this basis. The frequency regulation capability of the water turbine speed regulation system under the condition of high-proportion unconventional renewable energy grid connection can be effectively improved, and stable operation of a power system is ensured. Compared with an existing speed regulation system, the frequency regulation capacity of the water turbine speed regulation system under the high-proportion unconventional renewable energy source grid connection condition can be effectively improved, and stable operation of a power system is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of water turbine speed regulation, and relates to a simulation modeling method of a water turbine speed regulation system based on passive control. Background Art

[0002] As an important component of clean energy, the efficient and stable operation of hydropower is crucial to the stability of the power system. However, when faced with a high proportion of non-conventional renewable energy such as wind and solar energy, the traditional turbine speed control system may have insufficient frequency regulation capabilities due to the nonlinearity, complexity and time variability of the system itself. Therefore, it is necessary to study an advanced control system that can maintain high performance and stability over a wide range of operating conditions.

[0003] In order to solve the above problems, the study of control methods to ensure stability has attracted great attention in recent decades. Some control methods that consider unknown dynamics or uncertain parameters have been proposed. Although these controls have been proven to be robust at one operating point, they do not guarantee stability. On the other hand, recent studies have shown that the use of controls based on Hamiltonian dynamics has the potential to ensure stability. These controls are separated from the system dynamics and generate Hamiltonian models through orthogonal decomposition methods. In addition to being complex, this method also ignores the physical characteristics of the system. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a simulation modeling method for a turbine speed regulation system based on passive control, which is used to generate a more accurate and simple model with more physical meanings without deviating from the system dynamics and ignoring the system physical characteristics, and utilizes the natural structure of the turbine regulation system to obtain the Hamiltonian model of the system.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a simulation modeling method of a turbine speed regulation system based on passive control, comprising the following steps: S1, modeling, establishing a mathematical model of the turbine speed control system, which takes into account the dynamic characteristics of the pressure pipe, tunnel and turbine as well as the head loss; S2, simulation, based on the established mathematical model, simulation experiments are carried out using MATLAB software to verify the accuracy of the model and the effectiveness of the control strategy; S3, control, according to the passive control theory, appropriate parameters are selected and the control law is solved by substituting the actual and desired dynamic equations; S4, regulation, using adaptive sliding mode control or fuzzy sliding mode control strategy to improve the system's adaptability and robustness to changes in unknown parameters; S5, analysis and comparison, through simulation results analysis, compare the performance differences between traditional PID control and the control strategy of this system under different working conditions.

[0006] In S1, the mathematical model of the turbine speed control system is established as follows: ; (1) Among them, h is the unit head, kf is the friction loss on the pipeline, q is the standardized flow rate on the pressure pipeline, and Tw is the start time of water flow on the pressure pipeline; ; (2) Where qbase is the turbine flow rate when the gate is fully open, hbase is the static head of the water column above the turbine, L and A are the length and area of ​​the pressure pipe, and g is the acceleration due to gravity; The position of the servo motor in the turbine speed control system is defined as: (3) Among them, Ty is the time constant of the servo motor, y is the gate position vector, and u is the output control vector of the speed regulator control unit.

[0007] In S1, the classical model of the hydro-generator, namely the second-order model, is also included, which is defined as: ; ; (4) in, and They represent the relative deviation of rotor angle and turbine speed respectively, H is the turbine inertia time constant, is the angular velocity of the generator, is the power of the turbine, is the maximum electromagnetic power of the power system.

[0008] In S3, including the control unit, the port Hamiltonian model is established according to the mathematical model of the turbine speed control system: (5) Define the following state variables: x1=M ,x2= , x3=Tyy, x4=Twq, the port Hamiltonian model is: (6) in, is the antisymmetric matrix of the interconnection matrix, is the dissipation matrix, is the Hamiltonian function, G is a matrix, is an external disturbance independent of the state variables, () represents the gradient operator; Consider the expected dynamics of the error defined below: (7) in, is the dynamic characteristics of the error; In order to obtain the general control input, the system defined by formula (6) is replaced by the system defined by formula (7), and the following is obtained: (8).

[0009] The main beneficial effects of the present invention are: Without departing from the system dynamics and ignoring the system physical characteristics, it is used to generate more accurate and simple models with physical meanings, and to obtain the Hamiltonian model of the system by utilizing the natural structure of the turbine regulation system.

[0010] The dynamic behavior of the turbine speed regulation system is accurately described by constructing a port Hamiltonian model, and on this basis a control strategy is designed to ensure the global asymptotic stability of the system.

[0011] It can effectively improve the frequency regulation capability of the turbine speed control system when a high proportion of unconventional renewable energy is connected to the grid, ensuring the stable operation of the power system.

[0012] Compared with the existing speed control system, it can effectively improve the frequency regulation capability of the turbine speed control system when a high proportion of unconventional renewable energy is connected to the grid, ensuring the stable operation of the power system.

[0013] It also has the advantages of clear physical meaning, high model accuracy and strong adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0015] Figure 1 It is a system block diagram of the present invention. DETAILED DESCRIPTION

[0016] like Figure 1 A simulation modeling method for a turbine speed control system based on passive control includes the following steps: S1, modeling, establishing a mathematical model of the turbine speed control system, which takes into account the dynamic characteristics of the pressure pipe, tunnel and turbine as well as the head loss; S2, simulation, based on the established mathematical model, simulation experiments are carried out using MATLAB software to verify the accuracy of the model and the effectiveness of the control strategy; S3, control, according to the passive control theory, appropriate parameters are selected and the control law is solved by substituting the actual and desired dynamic equations; S4, regulation, using adaptive sliding mode control or fuzzy sliding mode control strategy to improve the system's adaptability and robustness to changes in unknown parameters; S5, analysis and comparison, through simulation results analysis, compare the performance differences between traditional PID control and the control strategy of this system under different working conditions.

[0017] Preferably, the turbine speed regulation system model mainly includes a modeling unit, a simulation unit, a control unit, a regulating unit and a comparative analysis unit.

[0018] In the preferred solution, in S1, the mathematical model of the turbine speed control system is established as follows: ; (1) Among them, h is the unit head, kf is the friction loss on the pipeline, q is the standardized flow rate on the pressure pipeline, and Tw is the start time of water flow on the pressure pipeline; ; (2) Where qbase is the turbine flow rate when the gate is fully open, hbase is the static head of the water column above the turbine, L and A are the length and area of ​​the pressure pipe, and g is the acceleration due to gravity; The position of the servo motor in the turbine speed control system is defined as: (3) Among them, Ty is the time constant of the servo motor, y is the gate position vector, and u is the output control vector of the speed regulator control unit.

[0019] In the preferred solution, in S1, the classical model of the hydro-generator, i.e., the second-order model, is also included, which is defined as: ; ; (4) in, and They represent the relative deviation of rotor angle and turbine speed respectively, H is the turbine inertia time constant, is the angular velocity of the generator, is the power of the turbine, is the maximum electromagnetic power of the power system.

[0020] In the preferred solution, in S3, a control unit is included to establish a port Hamiltonian model according to the mathematical model of the turbine speed control system: ; (5) Define the following state variables: x1=M ,x2= , x3=Tyy, x4=Twq, the port Hamiltonian model is: (6) in, is the antisymmetric matrix of the interconnection matrix, is the dissipation matrix, is the Hamiltonian function, G is a matrix, is an external disturbance independent of the state variables, () represents the gradient operator; Consider the expected dynamics of the error defined below: (7) in, is the dynamic characteristics of the error; In order to obtain the general control input, the system defined by formula (6) is replaced by the system defined by formula (7), and the following is obtained: (8).

[0021] Without departing from the system dynamics and ignoring the system physical characteristics, it is used to generate more accurate and simple models with physical meanings, and to obtain the Hamiltonian model of the system by utilizing the natural structure of the turbine regulation system.

[0022] In the above method, the dynamic behavior of the turbine speed control system is accurately described by constructing a port Hamiltonian model, and on this basis, a control strategy that can ensure the global asymptotic stability of the system is designed.

[0023] It can effectively improve the frequency regulation capability of the turbine speed control system when a high proportion of unconventional renewable energy is connected to the grid, ensuring the stable operation of the power system.

[0024] Compared with the existing speed control system, it can effectively improve the frequency regulation capability of the turbine speed control system when a high proportion of unconventional renewable energy is connected to the grid, ensuring the stable operation of the power system.

[0025] It also has the advantages of clear physical meaning, high model accuracy and strong adaptability.

[0026] The above-mentioned embodiments are only preferred technical solutions of the present invention and should not be regarded as limitations of the present invention. The embodiments and features in the embodiments of the present application can be arbitrarily combined with each other without conflict. The protection scope of the present invention shall be the technical solutions recorded in the claims, including the equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A simulation modeling method for a turbine speed control system based on passive control, characterized in that , including the following steps: S1, modeling, establishing a mathematical model of the turbine speed control system, which takes into account the dynamic characteristics of the pressure pipe, tunnel and turbine as well as the head loss; S2, simulation, based on the established mathematical model, simulation experiments are carried out using MATLAB software to verify the accuracy of the model and the effectiveness of the control strategy; S3, control, according to the passive control theory, appropriate parameters are selected and the control law is solved by substituting the actual and desired dynamic equations; S4, regulation, using adaptive sliding mode control or fuzzy sliding mode control strategy to improve the system's adaptability and robustness to changes in unknown parameters; S5, analysis and comparison, through simulation results analysis, compare the performance differences between traditional PID control and the control strategy of this system under different working conditions.

2. The method for simulating and modeling a turbine speed regulating system based on passive control according to claim 1 is characterized in that: In S1, the mathematical model of the turbine speed control system is established as follows: ；（1） Among them, h is the unit head, kf is the friction loss on the pipeline, q is the standardized flow rate on the pressure pipeline, and Tw is the start time of water flow on the pressure pipeline; ；（2） Where qbase is the turbine flow rate when the gate is fully open, hbase is the static head of the water column above the turbine, L and A are the length and area of ​​the pressure pipe, and g is the acceleration due to gravity; The position of the servo motor in the turbine speed control system is defined as: （3） Among them, Ty is the time constant of the servo motor, y is the gate position vector, and u is the output control vector of the speed regulator control unit.

3. The simulation modeling method for a water turbine speed regulation system based on passive control according to claim 2 is characterized in that: S1 also includes the classic model of the hydro-generator, namely the second-order model, which is defined as: ； ； （4） in, and They represent the relative deviation of rotor angle and turbine speed respectively, H is the turbine inertia time constant, is the angular velocity of the generator, is the power of the turbine, is the maximum electromagnetic power of the power system.

4. The simulation modeling method of a water turbine speed regulation system based on passive control according to claim 1 is characterized in that: In S3, including the control unit, the port Hamiltonian model is established according to the mathematical model of the turbine speed control system: ；（5） Define the following state variables: x1=M ,x2= , x3=Tyy, x4=Twq, the port Hamiltonian model is: （6） in, is the antisymmetric matrix of the interconnection matrix, is the dissipation matrix, is the Hamiltonian function, G is a matrix, is an external disturbance independent of the state variables, () represents the gradient operator; Consider the expected dynamics of the error defined below: ；（7） in, is the dynamic characteristics of the error; In order to obtain the general control input, the system defined by formula (6) is replaced by the system defined by formula (7), and we get: （8）。

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