Combined frequency modulation control method for thermal power generating unit and compressed air energy storage system

Abstract

The invention relates to a thermal power generating unit and compressed air energy storage system combined frequency modulation control method, which comprises the following steps: constructing a thermal power generating unit and compressed air energy storage system combined frequency modulation cooperative control model, performing wavelet transform on a power grid frequency deviation signal, decomposing a frequency band, and combining the model to establish a state space model; dynamically updating a weight matrix of the quadratic performance index function, and solving a Riccati equation by combining the constraint and the state space model to obtain an optimal gain matrix; and calculating a cooperative control instruction to realize cooperative frequency modulation of the thermal power generating unit and the compressed air energy storage system. Therefore, by establishing a joint frequency modulation model of the thermal power generating unit and the compressed air energy storage system, designing a self-adaptive distribution strategy and combining the LQR, multi-target optimization control of charging and discharging of the compressed air energy storage system is achieved, and the problems of frequency deviation, high power fluctuation of the thermal power generating unit and unstable frequency of a high-proportion new energy power grid are solved; and the regulation and control efficiency and the state stability of the compressed air energy storage system are greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power system frequency control, in particular to a combined frequency modulation control method of a thermal power unit and a compressed air energy storage system. BACKGROUND

[0002] With large-scale access of renewable energy to the power grid, its intermittency and volatility bring serious challenges to power system frequency stability. In order to cope with this challenge, it is necessary to strengthen the frequency modulation capability of the power system, which in turn requires the exploration of diversified energy storage solutions. At present, thermal power generation has long dominated China's energy structure and will play an important role in the transformation of China's energy structure. Therefore, improving the flexibility of TPU (Turbine Protection Unit, thermal power unit) is of great significance to adapt to high proportion of new energy penetration and enhance the flexible regulation capability of new power system. However, due to their inherent characteristics, they cannot quickly adapt to fluctuations in grid frequency. In addition, frequent and sudden changes in TPU load can lead to pressure oscillation and combustion instability, threatening the safe and stable operation of the unit. In order to alleviate these concerns, CAES (Compressed Air Energy Storage System) has become an important means to improve the frequency modulation performance of the power grid with its fast bidirectional response speed, high regulation accuracy and other characteristics. Its fast charging response can quickly switch to compression energy storage mode to absorb excess power and suppress frequency rise when the grid frequency is higher than the rated value, and its fast discharge response can start the expansion power generation mode within seconds to release compressed air to supplement active power and suppress frequency drop when the grid frequency is lower than the rated value. The high regulation accuracy is due to the high response speed of the compressed air energy storage system in a short time scale and its adaptability to complex dynamic conditions.

[0003] However, the combined frequency modulation control strategy of thermal power units and compressed air energy storage systems in the related art still needs to be optimized in terms of power distribution rationality, energy storage state management and multi-constraint adaptability, and needs to be solved urgently. SUMMARY

[0004] The present application provides a combined frequency modulation control method of a thermal power unit and a compressed air energy storage system to solve the problems of high frequency deviation and power fluctuation of thermal power units and frequency instability of high proportion of new energy power grids, greatly improving the regulation efficiency and state stability of the compressed air energy storage system.

[0005] To achieve the above purpose, the first aspect of the present application provides a combined frequency modulation control method of a thermal power unit and a compressed air energy storage system, comprising the following steps: constructing a combined frequency modulation collaborative control model of a thermal power unit and a compressed air energy storage system; performing wavelet transform on the power grid frequency deviation signal, and obtaining a frequency band allocation result according to a result of the transform, and establishing a state space model according to the frequency band allocation result based on the joint frequency modulation cooperative control model; based on the state space model, constructing a quadratic performance index function, and dynamically updating a weight matrix of the quadratic performance index function; and solving a preset continuous-time algebraic Riccati equation according to the updated weight matrix, a preset control input smoothness constraint, and the state space model to obtain an optimal gain matrix; calculating cooperative control instructions of the thermal power generating unit and the compressed air energy storage system according to the optimal gain matrix, so as to cooperatively control frequency modulation of the thermal power generating unit and the compressed air energy storage system according to the cooperative control instructions.

[0006] According to an embodiment of the present application, the joint frequency modulation cooperative control model of the thermal power generating unit and the compressed air energy storage system is constructed, including: constructing a frequency response model based on a power system frequency dynamic equation; building a dynamic model of the thermal power generating unit through a steam turbine-governor transfer function; building a dynamic model of the compressed air energy storage system based on thermodynamic characteristics of the compressed air energy storage system; obtaining the joint frequency modulation cooperative control model according to the frequency response model, the dynamic model of the thermal power generating unit, and the dynamic model of the compressed air energy storage system based on a preset constraint condition set.

[0007] According to an embodiment of the present application, the frequency response model is: ; the dynamic model of the thermal power generating unit is: ; the dynamic model of the compressed air energy storage system is: ; ; ; ; ; wherein, is a system inertia time constant, is a load damping coefficient, is a frequency deviation, is a joint output of the thermal power generating unit and the compressed air energy storage system, is a change amount of load power, is a new energy output fluctuation, / / The power percentage of each cylinder, / / The steam volume time constant is , These are the charging power and discharging power of the compressed air energy storage system, respectively. , For a series, , For airflow, The specific heat capacity of air at constant pressure. , For mechanical efficiency, , For temperature parameters, This represents the power change of the thermal power unit. The power change of the compressed air energy storage system is represented by ; SOC represents the state of charge of the compressed air energy storage system. The ramp rate limit for TPU.

[0008] According to one embodiment of this application, the state-space model is as follows: ; in, , d = , For frequency deviation, For TPU output changes, For changes in output and energy storage status of compressed air energy storage systems For state vectors, To select a reference power command, For PID (Proportional-Integral-Derivative) controllers, the proportional coefficient is... is the integral coefficient.

[0009] According to one embodiment of this application, the frequency band allocation result includes a first frequency component higher than a preset frequency and a second frequency component lower than the preset frequency, wherein... The compressed air energy storage system performs power regulation based on the first frequency component in the frequency band allocation result, and the thermal power unit performs power regulation based on the second frequency component in the frequency band allocation result.

[0010] According to the embodiments of this application, a joint frequency regulation control method for thermal power units and compressed air energy storage systems is proposed. By establishing a joint frequency regulation model for thermal power units and compressed air energy storage systems, a power adaptive allocation strategy based on nonlinear signal decomposition is designed. Combined with LQR, multi-objective optimization control of the charging and discharging process of compressed air energy storage systems is achieved. This solves the problems of high frequency deviation and power fluctuation of thermal power units and frequency instability of high-proportion renewable energy grids, and greatly improves the regulation efficiency and state stability of compressed air energy storage systems.

[0011] To achieve the above objectives, a second aspect of this application provides a joint frequency regulation control device for a thermal power unit and a compressed air energy storage system, comprising: The module is used to build a joint frequency regulation and coordinated control model for thermal power units and compressed air energy storage systems; The allocation module is used to perform wavelet transform on the power grid frequency deviation signal, and decompose the frequency band allocation result according to the transform result. Based on the joint frequency modulation and coordinated control model, a state space model is established according to the frequency band allocation result. The solution module constructs a quadratic performance index function based on the state-space model and dynamically updates the weight matrix of the quadratic performance index function; it then solves the preset continuous-time algebraic Riccati equation to obtain the optimal gain matrix based on the updated weight matrix, preset control input smoothness constraints, and the state-space model. The control module is used to calculate the coordinated control command of the thermal power unit and the compressed air energy storage system according to the optimal gain matrix, so as to coordinate the frequency regulation control of the thermal power unit and the compressed air energy storage system according to the coordinated control command.

[0012] According to one embodiment of this application, the construction module further includes: A frequency response model is constructed based on the frequency dynamic equations of the power system. A dynamic model of the thermal power unit was constructed using the turbine-governor transfer function. Based on the thermodynamic characteristics of the compressed air energy storage system, a dynamic model of the compressed air energy storage system is constructed. Based on a preset set of constraints, the joint frequency regulation and coordinated control model is obtained according to the frequency response model, the dynamic model of the thermal power unit, and the dynamic model of the compressed air energy storage system.

[0013] According to one embodiment of this application, the frequency response model is: ; The dynamic model of the thermal power unit is as follows: ; The dynamic model of the compressed air energy storage system is as follows: ; ; ; ; ; in, Let be the system's inertial time constant. This is the load damping coefficient. For frequency deviation, To provide combined power for thermal power units and compressed air energy storage systems, This represents the change in load power. Fluctuations in the contribution of new energy sources / / The power percentage of each cylinder, / / The steam volume time constant is , These are the charging power and discharging power of the compressed air energy storage system, respectively. , For a series, , For airflow, The specific heat capacity of air at constant pressure. , For mechanical efficiency, , For temperature parameters, This represents the power change of the thermal power unit. The power change of the compressed air energy storage system is represented by ; SOC represents the state of charge of the compressed air energy storage system. The ramp rate limit for TPU.

[0014] According to one embodiment of this application, the state-space model is as follows: ; in, , d = , For frequency deviation, For TPU output changes, For changes in output and energy storage status of compressed air energy storage systems For state vectors, To select a reference power command, The proportional gain of the PID controller. is the integral coefficient.

[0015] According to one embodiment of this application, the frequency band allocation result includes a first frequency component higher than a preset frequency and a second frequency component lower than the preset frequency, wherein... The compressed air energy storage system performs power regulation based on the first frequency component in the frequency band allocation result, and the thermal power unit performs power regulation based on the second frequency component in the frequency band allocation result.

[0016] According to the embodiments of this application, a joint frequency regulation control device for thermal power units and compressed air energy storage systems is proposed. By establishing a joint frequency regulation model for thermal power units and compressed air energy storage systems, a power adaptive allocation strategy based on nonlinear signal decomposition is designed. Combined with LQR, multi-objective optimization control of the charging and discharging process of compressed air energy storage systems is realized. This solves the problems of high frequency deviation and power fluctuation of thermal power units and frequency instability of high-proportion renewable energy grids, and greatly improves the regulation efficiency and state stability of compressed air energy storage systems.

[0017] To achieve the above objectives, a third aspect of this application provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the joint frequency regulation control method for thermal power units and compressed air energy storage systems as described in the above embodiments.

[0018] To achieve the above objectives, a fourth aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the joint frequency regulation control method for thermal power units and compressed air energy storage systems as described in the above embodiments.

[0019] To achieve the above objectives, the fifth aspect of this application provides a computer program product, including a computer program that is executed by a processor to implement the joint frequency regulation control method for thermal power units and compressed air energy storage systems as described in the above embodiments.

[0020] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0021] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a flowchart of a joint frequency regulation control method for a thermal power unit and a compressed air energy storage system according to an embodiment of this application; Figure 2This is a collaborative control model for a thermal power unit and a compressed air energy storage system according to an embodiment of this application; Figure 3 A flowchart illustrating the design of an LQR controller according to an embodiment of this application; Figure 4 This is a block diagram of a joint frequency regulation control method for a thermal power unit and a compressed air energy storage system provided according to an embodiment of this application; Figure 5 This is a schematic diagram of the structure of an electronic device provided according to an embodiment of this application. Detailed Implementation

[0022] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0023] The following description, with reference to the accompanying drawings, describes a joint frequency regulation control method for thermal power units and compressed air energy storage systems proposed according to embodiments of this application. Addressing the issues of high frequency deviation and power fluctuations in thermal power units, as well as frequency instability in high-proportion renewable energy power grids mentioned in the background art, embodiments of this application provide a joint frequency regulation control method for thermal power units and compressed air energy storage systems. By establishing a joint frequency regulation model for thermal power units and compressed air energy storage systems, designing a power adaptive allocation strategy based on nonlinear signal decomposition, and combining LQR to achieve multi-objective optimization control of the charging and discharging process of the compressed air energy storage system, this method solves the problems of high frequency deviation and power fluctuations in thermal power units, as well as frequency instability in high-proportion renewable energy power grids, significantly improving the regulation efficiency and state stability of the compressed air energy storage system.

[0024] First, the method for joint frequency regulation control of thermal power units and compressed air energy storage systems according to embodiments of this application will be described with reference to the accompanying drawings.

[0025] Figure 1 This is a flowchart of a method for joint frequency regulation control of a thermal power unit and a compressed air energy storage system according to an embodiment of this application.

[0026] like Figure 1 As shown, the joint frequency regulation control method of the thermal power unit and the compressed air energy storage system includes the following steps: In step S101, a joint frequency regulation and coordinated control model for thermal power units and compressed air energy storage systems is constructed.

[0027] Optionally, in some embodiments, a joint frequency regulation and coordinated control model for the thermal power unit and the compressed air energy storage system is constructed, including: constructing a frequency response model based on the power system frequency dynamic equation; building a dynamic model of the thermal power unit through the turbine-governor transfer function; building a dynamic model of the compressed air energy storage system based on the thermodynamic characteristics of the compressed air energy storage system; and obtaining the joint frequency regulation and coordinated control model based on a preset set of constraints, according to the frequency response model, the dynamic model of the thermal power unit, and the dynamic model of the compressed air energy storage system.

[0028] Among them, the power system frequency dynamic equation is a mathematical equation describing the change of power system frequency over time; the frequency response model is used to simulate the frequency change law of the entire power system under power disturbance; the dynamic model of thermal power unit is used to simulate the response characteristics of thermal power unit during frequency regulation; the dynamic model of compressed air energy storage system is used to simulate the dynamic behavior of compressed air energy storage system during frequency regulation; the preset constraint set can be a user-defined constraint set, a constraint set obtained through a finite number of experiments, or a constraint set obtained through a finite number of computer simulations, and no specific limitation is made here.

[0029] Specifically, by analyzing the frequency regulation demand of the power system and the dynamic characteristics of energy storage, a collaborative control model is constructed, consisting of a frequency response model, thermal power unit and compressed air energy storage system models, and a set of constraints. The frequency response model describes the inertial response and multi-timescale frequency regulation characteristics; the thermal power unit and compressed air energy storage system models integrate the thermodynamic processes of the compressed air energy storage system with the dynamics of the thermal power unit governor; the constraints cover power balance, energy storage capacity, equipment ramp-up rate, and grid security. This model systematically characterizes the multi-energy collaborative mechanism, providing accurate mathematical descriptions and boundary conditions for subsequent control algorithm design.

[0030] Furthermore, in some embodiments, the frequency response model is: ; The dynamic model of the thermal power unit is as follows: ; The dynamic model of the compressed air energy storage system is as follows: ; ; ; ; ; in, Let be the system's inertial time constant. This is the load damping coefficient. For frequency deviation, To provide combined power for thermal power units and compressed air energy storage systems, This represents the change in load power. Fluctuations in the contribution of new energy sources / / The power percentage of each cylinder, / / The steam volume time constant is , These are the charging power and discharging power of the compressed air energy storage system, respectively. , For a series, , For airflow, The specific heat capacity of air at constant pressure. , For mechanical efficiency, , For temperature parameters, This represents the power change of the thermal power unit. The power change of the compressed air energy storage system is represented by ; SOC represents the state of charge of the compressed air energy storage system. The ramp rate limit for TPU.

[0031] Furthermore, in some embodiments, the state-space model is as follows: ; in, , d = , For frequency deviation, For TPU output changes, For changes in output and energy storage status of compressed air energy storage systems For state vectors, To select a reference power command, The proportional gain of the PID controller. is the integral coefficient.

[0032] In step S102, wavelet transform is performed on the power grid frequency deviation signal, and frequency band allocation results are obtained by decomposing the transform results. Based on the joint frequency modulation and coordinated control model, a state space model is established according to the frequency band allocation results. Among them, the power grid frequency deviation signal refers to the difference between the actual power grid frequency and the rated frequency; wavelet transform is a signal processing method that can analyze signals in both the time and frequency domains simultaneously; state-space model is a mathematical model in control theory that describes the dynamic behavior of a system.

[0033] Specifically, regarding frequency domain decomposition and dynamic weight adjustment: (1) Power allocation is achieved through wavelet decomposition; The frequency deviation signal was decomposed into three levels using the db4 wavelet to extract high-frequency components (>1Hz) and low-frequency components (<1Hz).

[0034]

[0035]

[0036] Among them, high-frequency components The compressed air energy storage system responds to sudden load changes. Low-frequency component. The TPU responds to load changes.

[0037] (2) Dynamic weight adjustment based on SOC; By introducing a Logistic regression function to dynamically adjust the power distribution coefficient, the compressed air energy storage system is prevented from overcharging / over-discharging, ensuring that it operates within a safe range.

[0038] In charging mode, when SOC ≥ 0.8, the forced compressed air energy storage system stops charging, and the low-frequency components are entirely handled by the TPU; when 0.2 < SOC < 0.8, the allocation coefficient is:

[0039] Where r = 13 (adjusting slope), b = 0.4 (smoothing factor), S th =0.5 (threshold SOC).

[0040] In discharge mode, when SOC ≤ 0.2, the forced compressed air energy storage system stops discharging, and the low-frequency components are entirely handled by the TPU; when 0.2 < SOC < 0.8, the allocation coefficient is:

[0041] Therefore, to address the multi-scale characteristics of the frequency deviation signal, wavelet transform is employed to decompose it into high-frequency components (responded rapidly by the compressed air energy storage system) and low-frequency components (handled by the thermal power unit), achieving complementary advantages of different regulation resources. Simultaneously, the weight matrix of the LQR controller is dynamically adjusted based on the real-time operating status of the system (such as energy storage state of charge, load level, and renewable energy penetration rate), adaptively balancing frequency regulation speed and energy storage lifespan loss, thereby enhancing the robustness and flexibility of the control strategy in complex scenarios.

[0042] Furthermore, in some embodiments, the frequency band allocation result includes a first frequency component higher than a preset frequency and a second frequency component lower than a preset frequency, wherein the compressed air energy storage system performs power regulation based on the first frequency component in the frequency band allocation result, and the thermal power unit performs power regulation based on the second frequency component in the frequency band allocation result.

[0043] The first frequency component is a fluctuation component with a frequency higher than the preset frequency; the second frequency component is a fluctuation component with a frequency lower than the preset frequency; the preset frequency can be a frequency set by the user, a frequency obtained through a limited number of experiments, or a frequency obtained through a limited number of computer simulations, and is not specifically limited here. Specifically, compressed air energy storage systems handle the first frequency component, capable of releasing or absorbing power instantaneously, making them ideal for dealing with high-frequency, short-term frequency fluctuations. For example, when the power grid experiences a sudden frequency drop due to a fault, the compressed air energy storage system can immediately release stored compressed air to drive power generation, quickly compensating for the power shortfall and preventing further frequency drops. Thermal power units handle the second frequency component. Their advantage lies in their strong continuous output capability, providing stable high power output, but their response speed is slower. Therefore, they are more suitable for handling low-frequency, long-term frequency fluctuations. For example, when the electrical load gradually increases over several hours, thermal power units can continuously increase power generation by slowly increasing the steam output, maintaining system frequency stability.

[0044] Therefore, by having the fast-response compressed air energy storage system handle high-frequency fluctuations, the efficiency reduction or equipment damage caused by frequent and rapid adjustments of thermal power units can be avoided; and by having the thermal power units with strong continuous capacity handle low-frequency fluctuations, the energy storage capacity of the compressed air energy storage system can be avoided due to frequent charging and discharging. By handling high-frequency and low-frequency fluctuations separately, the adjustment conflict between the two can be reduced, making the frequency regulation process more accurate and economical.

[0045] In step S103, a quadratic performance index function is constructed based on the state-space model, and the weight matrix of the quadratic performance index function is dynamically updated; the optimal gain matrix is ​​obtained by solving the preset continuous-time algebraic Riccati equation based on the updated weight matrix, the preset control input smoothness constraint, and the state-space model. Among them, the quadratic performance index function is a mathematical function used to measure the performance of a control system; the weight matrix is ​​a relatively important matrix parameter in the quadratic performance index function used to adjust the state error term and the control cost term; the control input smoothness constraint is a restriction condition on the adjustment action of the equipment, requiring that the rate of change of the control input cannot be too large, so as to avoid drastic adjustment causing shock to the equipment or system; the continuous-time algebraic Riccati equation is the core equation for solving the optimal control of linear systems in control theory, and it is an algebraic equation in matrix form; the optimal gain matrix is ​​the key matrix obtained by solving the Riccati equation, which is used to calculate the optimal control input based on the real-time state.

[0046] Specifically, first, define the objective function: ; Among them, the weight matrix (Frequency Deviation Weight) priority), (Control input smoothness constraints).

[0047] Next, solve the Riccati equation: By solving the continuous-time algebraic Riccati equation: To obtain the optimal gain matrix To achieve state feedback control: .

[0048] Therefore, firstly, based on state-space theory, the system variables (frequency deviation, unit power, energy storage power, state of charge (SOC), etc.) and control inputs (reference power, PID parameters) are modeled as a linear dynamic system. Then, by designing a quadratic performance index function, multiple objectives such as frequency regulation accuracy, energy storage power fluctuation, and equipment losses are transformed into a weighted matrix optimization problem. Finally, the optimal feedback gain matrix is ​​solved using the continuous-time algebraic Riccati equation, achieving closed-loop optimization of the state feedback control law and ensuring that the system achieves globally optimal control performance under multi-objective constraints.

[0049] In step S104, the coordinated control command of the thermal power unit and the compressed air energy storage system is calculated based on the optimal gain matrix, so as to coordinate the frequency regulation control of the thermal power unit and the compressed air energy storage system according to the coordinated control command.

[0050] Among them, the coordinated control command is a specific operation command obtained by mathematical calculation based on the optimal gain matrix and the current real-time state of the power grid; the coordinated frequency regulation control refers to the thermal power unit and the compressed air energy storage system simultaneously executing adjustment actions according to the coordinated control commands they receive, so as to jointly maintain the stability of the power grid frequency.

[0051] Specifically, such as Figure 2 As shown, Figure 2 This is a collaborative control model for a thermal power unit and a compressed air energy storage system according to an embodiment of this application.

[0052] Among them, the frequency deviation output by the generator-load model , Each module is connected to a power adaptive allocation module in its corresponding region; the power adaptive allocation module generates an energy storage power reference command after processing. , Connect to the power limiting circuit in the corresponding area's energy storage power output control module, while the thermal power unit receives the power reference... , Connect to TPU; power limit output power , Connected to the LQR model, the control signals generated by the LQR model , Connected to a compressed air energy storage system, the compressed air energy storage system outputs power. , The combined power output of the thermal power units, regulated by the TPU, is connected to the generator-load model; the two areas are connected via a contact wire to transfer interactive power. Furthermore, the frequency deviation output by the generator-load model is fed back to the power adaptive allocation module, forming a closed loop.

[0053] Specifically, the power adaptive allocation module decomposes the adjustment requirements and assigns tasks to the compressed air energy storage system and the thermal power unit. The compressed air energy storage system responds quickly through LQR optimal control, and the thermal power unit adjusts synchronously. The two work together, coordinating power across multiple regions through the contact line, ultimately reducing the frequency deviation. Return to the allowed range.

[0054] In summary, the LQR controller design flowchart is as follows: Figure 3 As shown, Figure 3 This is a flowchart illustrating the design of an LQR controller according to an embodiment of this application.

[0055] S301, Start, entering the execution phase of the power grid frequency control strategy; S302, Establish a system state-space model to transform the dynamic characteristics of the power grid into a state-space model; S303, construct a quadratic performance index function, solve the Riccati equation, and form a state feedback control law; S304 continuously collects the difference between the actual frequency and the rated frequency of the power grid. This serves as the basis for determining whether adjustment is necessary; S305, Judgment Is it greater than the threshold? If > Threshold, proceed to step S306, if If the threshold is less than or equal to the threshold, proceed to step S307. S306 calculates the control quantity based on the LQR control law. When the frequency deviation exceeds the limit, the optimal control quantity is calculated according to the LQR control law and the current system state. S307: When the frequency deviation is within the allowable range, no new adjustment action is performed, and the current unit and energy storage output status is maintained. S308. Based on the control quantity calculated in step S306, drive the actuator to operate, adjust the power of the generator set or the charging and discharging power of the energy storage device, compensate for the power gap / surplus of the power grid, and suppress frequency fluctuations.

[0056] S309, Update system status. After power regulation, the grid frequency, unit / energy storage output and other system status will change, and the status variables need to be updated to provide the latest system status for the next control calculation. S310, determine whether the frequency is stable. If it is stable, execute S311. If it is unstable, return to step S304. S311, End.

[0057] Therefore, by pre-designing the optimal controller and dynamically controlling according to the frequency deviation, the optimality of the control strategy can be guaranteed, and the grid frequency fluctuations can be responded to in real time, thus achieving efficient and economical frequency stability control.

[0058] After completing the design of the LQR-based power grid frequency control strategy, this application embodiment also needs to verify the performance of the strategy under complex actual power grid conditions and optimize key parameters to ensure its engineering practicality and robustness, and carry out multi-scenario verification and parameter optimization work.

[0059] First, a test system with a high proportion of renewable energy sources was constructed based on actual power grid data to simulate typical operating conditions such as load surges and fluctuations in renewable energy output. Second, by comparing simulation results of traditional PID control, MPC (Model Predictive Control), and the strategy of this invention, the effectiveness of LQR control in frequency deviation suppression and power response speed was verified. Finally, a genetic algorithm was used to globally optimize the LQR parameters, improving the controller parameter combination and ensuring that the control strategy achieves an optimal balance between frequency stability and economical regulation under different operating conditions.

[0060] According to the joint frequency regulation control method of thermal power unit and compressed air energy storage system proposed in the embodiments of this application, by establishing a joint frequency regulation model of thermal power unit and compressed air energy storage system, designing a power adaptive allocation strategy based on nonlinear signal decomposition, and combining LQR to realize multi-objective optimization control of the charging and discharging process of compressed air energy storage system, the method solves the problems of high frequency deviation and power fluctuation of thermal power unit and frequency instability of high proportion of new energy grid, and greatly improves the regulation efficiency and state stability of compressed air energy storage system.

[0061] Next, referring to the accompanying drawings, a combined frequency regulation control device for thermal power units and compressed air energy storage systems according to embodiments of this application is described.

[0062] Figure 4 This is a block diagram of a combined frequency regulation control device for a thermal power unit and a compressed air energy storage system according to an embodiment of this application.

[0063] like Figure 4 As shown, the combined frequency regulation control device 10 for the thermal power unit and compressed air energy storage system includes: a construction module 100, a distribution module 200, a solution module 300, and a control module 400.

[0064] The module is used to build a joint frequency regulation and coordinated control model for thermal power units and compressed air energy storage systems; The allocation module is used to perform wavelet transform on the power grid frequency deviation signal, and decompose the frequency band allocation result according to the transform result. Based on the joint frequency modulation and coordinated control model, a state space model is established according to the frequency band allocation result. The solution module constructs a quadratic performance index function based on the state-space model and dynamically updates the weight matrix of the quadratic performance index function. Based on the updated weight matrix, the preset control input smoothness constraints, and the state-space model, it solves the preset continuous-time algebraic Riccati equation to obtain the optimal gain matrix. The control module is used to calculate the coordinated control commands for the thermal power unit and the compressed air energy storage system based on the optimal gain matrix, so as to coordinate the frequency regulation control of the thermal power unit and the compressed air energy storage system according to the coordinated control commands.

[0065] According to one embodiment of this application, the construction module further includes: constructing a frequency response model based on the power system frequency dynamic equation; building a dynamic model of a thermal power unit through the turbine-governor transfer function; building a dynamic model of a compressed air energy storage system based on the thermodynamic characteristics of the compressed air energy storage system; and obtaining a joint frequency regulation and coordinated control model based on a preset set of constraints, the frequency response model, the dynamic model of the thermal power unit, and the dynamic model of the compressed air energy storage system.

[0066] According to one embodiment of this application, the frequency response model is as follows: ; The dynamic model of the thermal power unit is as follows: ; The dynamic model of the compressed air energy storage system is as follows: ; ; ; ; ; in, Let be the system's inertial time constant. This is the load damping coefficient. For frequency deviation, To provide combined power for thermal power units and compressed air energy storage systems, This represents the change in load power. Fluctuations in the contribution of new energy sources / / The power percentage of each cylinder, / / The steam volume time constant is , These are the charging power and discharging power of the compressed air energy storage system, respectively. , For a series, , For airflow, The specific heat capacity of air at constant pressure. , For mechanical efficiency, , For temperature parameters, This represents the power change of the thermal power unit. The power change of the compressed air energy storage system is represented by ; SOC represents the state of charge of the compressed air energy storage system. The ramp rate limit for TPU.

[0067] According to one embodiment of this application, the state-space model is as follows: ; in, , d = , For frequency deviation, For TPU output changes, For changes in output and energy storage status of compressed air energy storage systems For state vectors, To select a reference power command, This is the proportional gain of the PID controller. is the integral coefficient.

[0068] According to one embodiment of this application, the frequency band allocation result includes a first frequency component higher than a preset frequency and a second frequency component lower than a preset frequency, wherein... The compressed air energy storage system performs power regulation based on the first frequency component of the frequency band allocation result, while the thermal power unit performs power regulation based on the second frequency component of the frequency band allocation result.

[0069] It should be noted that the foregoing explanation of the embodiment of the joint frequency regulation control method for thermal power units and compressed air energy storage systems also applies to the joint frequency regulation control device for thermal power units and compressed air energy storage systems in this embodiment, and will not be repeated here.

[0070] According to the joint frequency regulation control device for thermal power units and compressed air energy storage systems proposed in the embodiments of this application, by establishing a joint frequency regulation model for thermal power units and compressed air energy storage systems, designing a power adaptive allocation strategy based on nonlinear signal decomposition, and combining LQR to realize multi-objective optimization control of the charging and discharging process of compressed air energy storage systems, the device solves the problems of high frequency deviation and power fluctuation of thermal power units and frequency instability of high-proportion new energy power grids, and greatly improves the regulation efficiency and state stability of compressed air energy storage systems.

[0071] Figure 5 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. The electronic device may include: The memory 501, the processor 502, and the computer program stored on the memory 501 and capable of running on the processor 502.

[0072] When the processor 502 executes the program, it implements the joint frequency regulation control method of thermal power unit and compressed air energy storage system provided in the above embodiments.

[0073] Furthermore, electronic devices also include: Communication interface 503 is used for communication between memory 501 and processor 502.

[0074] The memory 501 is used to store computer programs that can run on the processor 502.

[0075] The memory 501 may include high-speed RAM (Random Access Memory) memory, and may also include non-volatile memory, such as at least one disk storage.

[0076] If the memory 501, processor 502, and communication interface 503 are implemented independently, then the communication interface 503, memory 501, and processor 502 can be interconnected via a bus to complete communication between them. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 5 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0077] Optionally, in a specific implementation, if the memory 501, processor 502, and communication interface 503 are integrated on a single chip, then the memory 501, processor 502, and communication interface 503 can communicate with each other through an internal interface.

[0078] Processor 502 may be a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement embodiments of the present invention.

[0079] This invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described joint frequency regulation control method for thermal power units and compressed air energy storage systems.

[0080] This invention also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described joint frequency regulation control method for thermal power units and compressed air energy storage systems.

[0081] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0082] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0083] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for joint frequency regulation control of a thermal power unit and a compressed air energy storage system, characterized in that, Includes the following steps: Construct a joint frequency regulation and coordinated control model for thermal power units and compressed air energy storage systems; Wavelet transform is performed on the power grid frequency deviation signal, and the frequency band allocation result is obtained by decomposing the transform result. Based on the joint frequency modulation and coordinated control model, a state space model is established according to the frequency band allocation result. Based on the state-space model, a quadratic performance index function is constructed, and the weight matrix of the quadratic performance index function is dynamically updated. The optimal gain matrix is ​​obtained by solving the preset continuous-time algebraic Riccati equation according to the updated weight matrix, the preset control input smoothness constraint, and the state-space model. The coordinated control command for the thermal power unit and the compressed air energy storage system is calculated based on the optimal gain matrix, so as to coordinate the frequency regulation control of the thermal power unit and the compressed air energy storage system according to the coordinated control command.

2. The method according to claim 1, characterized in that, The construction of the joint frequency regulation and coordinated control model for thermal power units and compressed air energy storage systems includes: A frequency response model is constructed based on the frequency dynamic equations of the power system. A dynamic model of the thermal power unit was constructed using the turbine-governor transfer function. Based on the thermodynamic characteristics of the compressed air energy storage system, a dynamic model of the compressed air energy storage system is constructed. Based on a preset set of constraints, the joint frequency regulation and coordinated control model is obtained according to the frequency response model, the dynamic model of the thermal power unit, and the dynamic model of the compressed air energy storage system.

3. The method according to claim 2, characterized in that, The frequency response model is as follows: ； The dynamic model of the thermal power unit is as follows: ； The dynamic model of the compressed air energy storage system is as follows: ； ； ； ； ； in, Let be the system's inertial time constant. This is the load damping coefficient. For frequency deviation, To provide combined power for thermal power units and compressed air energy storage systems, This represents the change in load power. Fluctuations in the contribution of new energy sources / / The power percentage of each cylinder, / / The steam volume time constant is , These are the charging power and discharging power of the compressed air energy storage system, respectively. , For a series, , For airflow, The specific heat capacity of air at constant pressure. , For mechanical efficiency, , For temperature parameters, This represents the power change of the thermal power unit. The power change of the compressed air energy storage system is represented by ; SOC represents the state of charge of the compressed air energy storage system. The ramp rate limit for TPU.

4. The method according to claim 1, characterized in that, The state-space model is as follows: ； in, , d = , For frequency deviation, For TPU output changes, For changes in output and energy storage status of compressed air energy storage systems For state vectors, To select a reference power command, The proportional gain of the PID controller. is the integral coefficient.

5. The method according to claim 1, characterized in that, The frequency band allocation result includes a first frequency component higher than a preset frequency and a second frequency component lower than the preset frequency, wherein... The compressed air energy storage system performs power regulation based on the first frequency component in the frequency band allocation result, and the thermal power unit performs power regulation based on the second frequency component in the frequency band allocation result.

6. A combined frequency regulation control device for a thermal power unit and a compressed air energy storage system, characterized in that, include: The module is used to build a joint frequency regulation and coordinated control model for thermal power units and compressed air energy storage systems; The allocation module is used to perform wavelet transform on the power grid frequency deviation signal, and decompose the frequency band allocation result according to the transform result. Based on the joint frequency modulation and coordinated control model, a state space model is established according to the frequency band allocation result. The solution module constructs a quadratic performance index function based on the state-space model and dynamically updates the weight matrix of the quadratic performance index function; it then solves the preset continuous-time algebraic Riccati equation to obtain the optimal gain matrix based on the updated weight matrix, preset control input smoothness constraints, and the state-space model. The control module is used to calculate the coordinated control command of the thermal power unit and the compressed air energy storage system according to the optimal gain matrix, so as to coordinate the frequency regulation control of the thermal power unit and the compressed air energy storage system according to the coordinated control command.

7. The apparatus according to claim 6, wherein the building module further comprises: A frequency response model is constructed based on the frequency dynamic equations of the power system. A dynamic model of the thermal power unit was constructed using the turbine-governor transfer function. Based on the thermodynamic characteristics of the compressed air energy storage system, a dynamic model of the compressed air energy storage system is constructed. Based on a preset set of constraints, the joint frequency regulation and coordinated control model is obtained according to the frequency response model, the dynamic model of the thermal power unit, and the dynamic model of the compressed air energy storage system.

8. An electronic device, characterized in that, include: The system includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the joint frequency regulation control method for thermal power units and compressed air energy storage systems as described in any one of claims 1-5.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the joint frequency regulation control method for thermal power units and compressed air energy storage systems as described in any one of claims 1-5.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the joint frequency regulation control method of thermal power unit and compressed air energy storage system as described in any one of claims 1-5.

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