Variable-speed pumped storage unit frequency modulation control method and device

Abstract

This application provides a frequency regulation control method and apparatus for a variable-speed pumped-storage unit, relating to the field of pumped-storage frequency regulation control technology. The method includes: constructing a linearized frequency response model of the variable-speed pumped-storage unit based on acquired unit operating parameters; generating auxiliary variables based on the linearized frequency response model; decoupling the linearized frequency response model using the auxiliary variables, and constructing a rotor speed controller and a guide vane opening controller respectively; and generating a coordinated control strategy based on the rotor speed controller and the guide vane opening controller to perform frequency regulation control on the variable-speed pumped-storage unit. The frequency regulation control method and apparatus for a variable-speed pumped-storage unit provided in this application effectively utilizes the guide vane opening frequency regulation capability and rotor kinetic energy, fully leveraging the unit's short-term and long-term frequency regulation capabilities, thereby improving the dynamic performance of the system frequency response containing the variable-speed pumped-storage unit.

Description

Technical Field

[0001] This application relates to the field of pumped storage frequency control technology, and in particular to a frequency control method and device for variable speed pumped storage units. Background Technology

[0002] As the penetration rate of renewable energy sources, such as wind and solar power, in the power system continues to increase, the overall rotational inertia of the system continues to decline, posing a more severe challenge to grid frequency stability. Variable-speed pumped-storage (VPS) units, due to their flexible power regulation characteristics, are considered an important regulatory resource for addressing these issues. These units can achieve large-capacity, continuous power regulation through guide vane opening and rapid speed control through rotor-side converters, thus possessing the potential to participate in grid frequency regulation. Fully leveraging the frequency regulation advantages of both guide vane opening regulation and rotor speed control is of great significance for deeply exploring the frequency regulation potential of VPS units and ensuring the frequency security of the new power system.

[0003] In existing technologies, methods for improving the frequency regulation capability of variable-speed pumped storage units mainly fall into three categories: first, optimizing guide vane opening control, such as by improving the optimal guide vane opening lookup table method or using improved algorithms to optimize traditional PID control; second, optimizing speed control, by improving the converter control method to allow the unit to release more rotor kinetic energy to participate in frequency support; and third, optimizing the unit's output power, by establishing an optimization function with optimal economic efficiency as the objective to determine the unit's optimal output power. However, the above control strategies usually process guide vane opening control and speed control independently or simply superimpose them, failing to fully leverage their synergistic advantages.

[0004] This section is intended to provide background or context for the embodiments of the invention set forth in the claims. The description herein is not an admission that it is prior art simply because it is included in this section. Summary of the Invention

[0005] To address the problems in the prior art, this application provides a frequency regulation control method and device for variable speed pumped storage units, which can solve the problems in the existing frequency regulation control of variable speed pumped storage units, such as slow response speed of guide vane opening adjustment, mutual coupling between rotor speed regulation and guide vane control and difficulty in coordinating the use of the two regulation resources, resulting in the unit being unable to simultaneously achieve both fast frequency response capability and continuous power support capability.

[0006] One aspect of the present invention provides a frequency regulation control method for a variable-speed pumped storage unit, the method comprising: A linearized frequency response model of the variable speed pumped storage unit was constructed based on the obtained unit operating parameters. Auxiliary variables are generated based on the linearized frequency response model; The linearized frequency response model is decoupled using the auxiliary variables, and a rotor speed controller and a guide vane opening controller are constructed respectively. A coordinated control strategy is generated based on the rotor speed controller and the guide vane opening controller to perform frequency regulation control on the variable speed pumped storage unit.

[0007] Furthermore, the step of constructing a linearized frequency response model for the variable-speed pumped storage unit based on the acquired unit operating parameters includes: Based on the unit's operating parameters, a first transmission model between the change in rotor speed and the change in mechanical power, and a second transmission model between the change in rotor speed and the change in electromagnetic power are established. A third transmission model is established based on the obtained unit inertia constant and damping coefficient to establish the relationship between the difference between the mechanical power change and the electromagnetic power change and the rotor speed change. The linearized frequency response model is constructed based on the first transfer model, the second transfer model, and the third transfer model.

[0008] Furthermore, the generation of auxiliary variables based on the linearized frequency response model includes: Based on the linearized frequency response model, a fourth transmission model between rotor speed power command and frequency response power, and a fifth transmission model between guide vane opening power command and frequency response power are established. The auxiliary variable is derived based on the fourth and fifth transfer models.

[0009] Furthermore, the step of decoupling the linearized frequency response model using the auxiliary variables and constructing the rotor speed controller and guide vane opening controller respectively includes: The auxiliary variables are used to decouple the guide vane opening control and rotor speed control in the linearized frequency response model to obtain the rotor speed control frequency response model and the guide vane opening control frequency response model. A rotor speed controller is constructed based on the rotor speed control frequency response model. A guide vane opening controller is constructed based on the guide vane opening control frequency response model.

[0010] Furthermore, the generation of a coordinated control strategy based on the rotor speed controller and the guide vane opening controller includes: Bode plot analysis was performed based on the rotor speed controller and the guide vane opening controller to obtain the frequency modulation characteristics and effective frequency modulation range of the guide vane opening control and the frequency modulation characteristics and effective frequency modulation range of the rotor speed control. A coordinated control strategy is generated based on the frequency modulation characteristics and effective frequency modulation range of the guide vane opening control and the frequency modulation characteristics and effective frequency modulation range of the rotor speed control.

[0011] Furthermore, it also includes: When a frequency disturbance occurs in the power grid, the corresponding control method is determined from the coordinated control strategy based on the obtained rotor speed of the unit after the frequency disturbance. The guide vane opening and rotor speed of the variable speed pumped storage unit are controlled in a coordinated manner according to the control method described above.

[0012] In another aspect, the present invention provides a frequency regulation control device for a variable speed pumped storage unit, the device comprising: The model building unit is used to build a linearized frequency response model of the variable speed pumped storage unit based on the acquired unit operating parameters. An auxiliary variable generation unit is used to generate auxiliary variables based on the linearized frequency response model. A control decoupling unit is used to decouple the linearized frequency response model using the auxiliary variables, and to construct a rotor speed controller and a guide vane opening controller respectively. The control strategy generation unit is used to generate a coordinated control strategy based on the rotor speed controller and the guide vane opening controller to perform frequency regulation control on the variable speed pumped storage unit.

[0013] Furthermore, the model building unit includes: The first model building module is used to build a first transmission model between the change in rotor speed and the change in mechanical power, and a second transmission model between the change in rotor speed and the change in electromagnetic power, based on the unit operating parameters. The second model building module is used to establish a third transmission model between the difference between the mechanical power change and the electromagnetic power change and the rotor speed change based on the obtained unit inertia constant and damping coefficient. The response model construction module is used to construct the linearized frequency response model based on the first transfer model, the second transfer model, and the third transfer model.

[0014] Furthermore, the auxiliary variable generation unit includes: The third model building module is used to build a fourth transmission model between rotor speed power command and frequency response power, and a fifth transmission model between guide vane opening power command and frequency response power, based on the linearized frequency response model. The auxiliary variable generation module is used to derive the auxiliary variables based on the fourth and fifth transfer models.

[0015] Furthermore, the control decoupling unit includes: The control decoupling module is used to decouple the guide vane opening control and rotor speed control in the linearized frequency response model using the auxiliary variables, so as to obtain the rotor speed control frequency response model and the guide vane opening control frequency response model. The first controller construction module is used to construct a rotor speed controller based on the rotor speed control frequency response model. The second controller construction module is used to construct a guide vane opening controller based on the guide vane opening control frequency response model.

[0016] Furthermore, the control strategy generation unit includes: The frequency modulation analysis module is used to perform Bode plot analysis based on the rotor speed controller and the guide vane opening controller to obtain the frequency modulation characteristics and effective frequency modulation range of the guide vane opening control and the frequency modulation characteristics and effective frequency modulation range of the rotor speed control. The control strategy generation module is used to generate a coordinated control strategy based on the frequency modulation characteristics and effective frequency modulation range of the guide vane opening control and the frequency modulation characteristics and effective frequency modulation range of the rotor speed control.

[0017] Furthermore, it also includes: The control method determination unit is used to determine the corresponding control method from the coordinated control strategy based on the obtained rotor speed of the unit after responding to the frequency disturbance when the power grid experiences a frequency disturbance. The collaborative control unit is used to collaboratively control the guide vane opening and rotor speed of the variable speed pumped storage unit according to the control method.

[0018] To achieve the above objectives, according to another aspect of the present invention, a computer device is also provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above-described variable speed pumped storage unit frequency regulation control method.

[0019] To achieve the above objectives, according to another aspect of the present invention, a computer-readable storage medium is also provided, on which a computer program / instruction is stored, which, when executed by a processor, implements the steps of the above-described variable-speed pumped storage unit frequency regulation control method.

[0020] To achieve the above objectives, according to another aspect of the present invention, a computer program product is also provided, comprising a computer program / instruction that, when executed by a processor, implements the steps of the above-described variable speed pumped storage unit frequency regulation control method.

[0021] The beneficial effects of this invention are as follows: This application decouples guide vane opening control from rotor speed control, enabling the unit to participate in grid frequency regulation using both rotor kinetic energy and guide vane opening adjustment capability, thus simultaneously possessing short-term rapid frequency support capability and long-term continuous power regulation capability. Furthermore, by constructing a coordinated control strategy for guide vane opening and rotor speed, speed control leverages its rapid dynamic response advantage, while guide vane opening adjustment leverages its wide-range power regulation advantage, effectively improving the variable-speed pumped storage unit's response capability to system frequency disturbances and its overall frequency regulation performance. In addition, this coordinated control strategy reduces frequent guide vane opening movements while achieving frequency regulation, thereby reducing mechanical wear and extending the mechanical service life of the pumped storage unit. Attached Figure Description

[0022] 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. In the drawings: Figure 1 This is a first flowchart illustrating the frequency regulation control method for variable speed pumped storage units provided in this embodiment of the invention. Figure 2 This is a second flowchart illustrating the frequency regulation control method for variable speed pumped storage units provided in this embodiment of the invention. Figure 3 This is a schematic diagram of the third process of the frequency regulation control method for variable speed pumped storage units provided in the embodiments of the present invention; Figure 4 This is a schematic diagram of the fourth process of the frequency regulation control method for variable speed pumped storage units provided in the embodiments of the present invention; Figure 5 This is a schematic diagram of the fifth process of the frequency regulation control method for variable speed pumped storage units provided in the embodiments of the present invention; Figure 6 This is a schematic diagram of the sixth process of the frequency regulation control method for variable speed pumped storage units provided in the embodiments of the present invention; Figure 7 This is a first structural schematic block diagram of the frequency regulation control device for variable speed pumped storage units provided in an embodiment of the present invention; Figure 8 This is a schematic block diagram of the second structure of the frequency regulation control device for variable speed pumped storage units provided in the embodiments of the present invention; Figure 9 This is a schematic block diagram of the third structure of the frequency regulation control device for variable speed pumped storage units provided in the embodiments of the present invention; Figure 10 This is a schematic block diagram of the fourth structure of the frequency regulation control device for variable speed pumped storage units provided in the embodiments of the present invention; Figure 11 This is a fifth structural schematic block diagram of the frequency regulation control device for variable speed pumped storage units provided in the embodiments of the present invention; Figure 12 This is a sixth structural schematic block diagram of the frequency regulation control device for variable speed pumped storage units provided in the embodiments of the present invention; Figure 13 This is a schematic diagram of the structure of the computer device provided in an embodiment of the present invention; Figure 14 This is a block diagram of the linearized frequency response control for variable-speed pumped storage provided in an embodiment of the present invention; Figure 15 This is a frequency response control block diagram after decoupling the guide vane opening control and rotor speed control of the variable speed pumped storage provided in this embodiment of the invention. Figure 16 This is a structural block diagram of the variable speed pumped storage guide vane opening controller provided in an embodiment of the present invention; Figure 17 This is a structural block diagram of the variable speed pumped storage rotor speed controller provided in an embodiment of the present invention; Figure 18 These are the Bode plot curves of the variable speed pumped storage guide vane opening controller and rotor speed control provided in this embodiment of the invention; Figure 19 This is a flowchart of the coordinated control strategy for guide vane opening and rotor speed of the variable speed pumped storage unit provided in the embodiments of the present invention. Figure 20 This is a schematic diagram of the overall process of frequency regulation control of variable speed pumped storage unit provided in an embodiment of the present invention; Figure 21 This is a linearized frequency response model of a power system containing variable-speed pumped storage provided in an embodiment of the present invention; Figure 22 This is a dynamic response diagram of the system after a sudden load increase, provided in an embodiment of the present invention. Figure 22 Part (a) is a diagram of power system frequency fluctuations; Figure 22 Part (b) is the curve showing the change in the guide vane opening of the variable speed pumped storage system. Figure 23 This is a system dynamic response diagram provided in an embodiment of the present invention after applying fluctuating wind power load, wherein... Figure 23 Part (a) is a diagram of power system frequency fluctuations; Figure 23 Part (b) is the curve showing the change in the guide vane opening of the variable speed pumped storage system. Detailed Implementation

[0023] 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.

[0024] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0025] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims and accompanying drawings of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes 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 devices.

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] The following describes the specific implementation process of the frequency regulation control method for variable speed pumped storage units provided in this application embodiment, using a server as the execution subject as an example.

[0028] Figure 1 This is a schematic diagram of the first process of the frequency regulation control method for variable speed pumped storage units provided in an embodiment of the present invention, as shown below. Figure 1 As shown, in one embodiment of the present invention, the frequency regulation control method for variable speed pumped storage units includes: S101: Construct a linearized frequency response model for the variable-speed pumped storage unit based on the obtained unit operating parameters; S102: Generate auxiliary variables based on the linearized frequency response model; S103: Decouple the linearized frequency response model using the auxiliary variables, and construct the rotor speed controller and guide vane opening controller respectively; S104: Generate a coordinated control strategy based on the rotor speed controller and the guide vane opening controller to perform frequency regulation control on the variable speed pumped storage unit.

[0029] from Figure 1 As shown in the flowchart, the frequency regulation control method for variable-speed pumped storage units provided in this application constructs a linearized frequency response model of the variable-speed pumped storage unit based on the acquired unit operating parameters; generates auxiliary variables based on the linearized frequency response model; decouples the linearized frequency response model using the auxiliary variables and constructs a rotor speed controller and a guide vane opening controller respectively; and generates a coordinated control strategy based on the rotor speed controller and the guide vane opening controller to perform frequency regulation control on the variable-speed pumped storage unit. This achieves effective utilization of the guide vane opening frequency regulation capability and rotor kinetic energy, fully leverages the unit's short-term and long-term frequency regulation capabilities, and thus improves the dynamic performance of the system frequency response containing the variable-speed pumped storage unit.

[0030] Each step is explained in detail below.

[0031] S101: Construct a linearized frequency response model for the variable-speed pumped storage unit based on the obtained unit operating parameters; Specifically, the server acquires the operating parameters of the variable-speed pumped-storage unit and constructs a linearized frequency response model of the unit based on these parameters. The server obtains key operating parameters of the unit under its current operating state, including rotor speed, mechanical power, electromagnetic power, and unit inertia parameters. Using the unit's current operating point as a reference, the server performs small-signal linearization processing on the dynamic relationships of the unit, thereby establishing a linearized frequency response model that describes the dynamic relationship between changes in unit power and changes in rotor speed. This model reflects the dynamic coupling relationship between mechanical power, electromagnetic power, and rotor speed under frequency disturbance conditions, providing a foundation for subsequent control strategy design.

[0032] Figure 2 This is a schematic diagram of the second process of the frequency regulation control method for variable speed pumped storage units provided in an embodiment of the present invention, as shown below. Figure 2 As shown, in one embodiment of the present invention, S101 includes: S201: Based on the unit operating parameters, establish a first transmission model between the change in rotor speed and the change in mechanical power, and a second transmission model between the change in rotor speed and the change in electromagnetic power; Specifically, the server acquires the operating parameters of the variable-speed pumped-storage unit under its current operating condition, including rotor speed, mechanical power, electromagnetic power, and unit operating status. Using the current operating point as a benchmark, the server performs small-signal linearization on the unit's power relationship. By analyzing the impact of rotor speed changes on the turbine's output mechanical power, the server establishes a dynamic transmission relationship between rotor speed changes and mechanical power changes to characterize the mechanical power response characteristics of the unit's hydraulic system under speed variation conditions. Simultaneously, based on the relationship between generator electromagnetic power and rotor speed, the server establishes a dynamic transmission relationship between rotor speed changes and electromagnetic power changes, thus obtaining a second transmission model that reflects the generator's electromagnetic power response characteristics. By establishing these two transmission models, the impact of rotor speed changes on mechanical power output and electromagnetic power output can be described separately.

[0033] S202: Based on the obtained unit inertia constant and damping coefficient, establish a third transmission model between the difference between the mechanical power change and the electromagnetic power change and the rotor speed change; Specifically, the server utilizes the rotor dynamics of the unit to model the imbalance between the unit's mechanical and electromagnetic power, and describes the dynamic response of the unit's rotor under power imbalance conditions using the unit's inertia constant and damping coefficient. Through this modeling process, the server establishes a dynamic transmission relationship between the difference between the changes in mechanical and electromagnetic power and the changes in rotor speed, thus forming a third transmission model that reflects the unit's rotor dynamic characteristics. This model is used to describe how the unit's rotor speed changes over time when an imbalance occurs between mechanical and electromagnetic power.

[0034] S203: Construct the linearized frequency response model based on the first transfer model, the second transfer model, and the third transfer model.

[0035] Specifically, the server combines the three transfer models mentioned above to establish a dynamic coupling relationship between the unit's mechanical power, electromagnetic power, and rotor speed, thereby obtaining a linearized frequency response model that reflects the unit's dynamic response characteristics under frequency disturbance conditions. Through this model, the server can describe the dynamic response process between the unit's power output and rotor speed when the system frequency changes, providing a foundation for subsequent control strategy design and unit frequency regulation control.

[0036] In one embodiment, the linearized frequency response model of the variable-speed pumped storage unit under power generation conditions is as follows: Figure 14 As shown, the variable speed pumped storage unit mainly provides power support by adjusting the guide vane opening and rotor speed. In maximum power tracking mode, the unit speed and guide vane opening are coupled together.

[0037] In the mechanical aspect, the pumped storage unit extracts mechanical power from the water. P m Represented as: (1) (2) (3) (4) in, Indicates the power factor. These represent characteristic parameters of variable-speed pumped storage operation. This indicates the flow rate of the variable speed pumped storage unit. This indicates the effective head of the variable speed pumped storage unit. For intermediate calculation variables, This indicates the radius of the turbine blade. This indicates the area of ​​the turbine blades. This indicates the rotor speed of the variable speed pumped storage unit. , , , , , , , and The fitting coefficients represent the mechanical power curve. From formulas (1) to (4), it can be seen that the effective power of the pumped storage unit is mainly related to the guide vane opening and the rotational speed. Using the small-signal analysis method, the transfer function (first transfer model) of the output mechanical power of the variable speed pumped storage unit with respect to the rotor speed is obtained as follows: (5) In the electromagnetic circuit, the variable-speed pumped storage unit operates in maximum power point tracking mode, at which point the system output mechanical power is a quadratic function of the rotor speed: (6) in, P e Electromagnetic power output for variable speed pumped storage units. d 0、 d 1. d 2 represents the fitting parameters for the maximum power point tracking curve. This represents the rotor speed.

[0038] According to formula (5), the electromagnetic power output of the unit at the initial operating point Expanding on this point, we can obtain the transfer function of the electromagnetic power of the variable-speed pumped-storage unit with respect to the rotor speed (second transfer model) as follows: (7) in, The electromagnetic power transfer function of a variable-speed pumped storage unit is given by the rotor speed. It is the initial rotor speed of the pumped storage unit.

[0039] Mechanical power and electromagnetic power are used to regulate the rotor speed through the rotor motion equation, resulting in the third transmission model: (8) in, Let be the transfer function of the rotor speed of a variable-speed pumped-storage unit with respect to the difference between mechanical power and electromagnetic power. H V It is the inertia constant of the pumped-storage unit. D V is the damping coefficient of the pumped storage unit.

[0040] S102: Generate auxiliary variables based on the linearized frequency response model; Specifically, the server mathematically organizes and derives the power response relationship in the linearized frequency response model, and generates auxiliary variables for subsequent control decoupling by performing an equivalent transformation on the model's transitive relationships. By introducing auxiliary variables, different control actions that were originally coupled in the same power response relationship can be separated, thus providing a foundation for constructing independent control structures.

[0041] Figure 3 This is a schematic diagram of the third process of the frequency regulation control method for variable speed pumped storage units provided in this embodiment of the invention, as shown below. Figure 3 As shown, in one embodiment of the present invention, S102 includes: S301: Based on the linearized frequency response model, establish a fourth transmission model between rotor speed power command and frequency response power, and a fifth transmission model between guide vane opening power command and frequency response power; Specifically, the server analyzes the power response relationship in the linearized frequency response model, representing the unit's frequency response power under frequency disturbance conditions as power response components caused by different control inputs. Based on the dynamic relationship between power change and control input in the linearized frequency response model, the server models the relationship between rotor speed power command and frequency response power, thus establishing a dynamic transmission relationship between rotor speed power command and frequency response power—the fourth transmission model—to describe the impact of rotor speed control on the unit's frequency response power. Simultaneously, based on the effect of mechanical power changes caused by guide vane opening adjustment on the unit's frequency response power, the server establishes a dynamic transmission relationship between guide vane opening power command and frequency response power, thus obtaining a fifth transmission model between guide vane opening power command and frequency response power. By establishing these two transmission models, the paths of rotor speed control and guide vane opening control on the unit's frequency response power can be characterized, respectively.

[0042] S302: The auxiliary variable is obtained by derivation based on the fourth and fifth transfer models.

[0043] Specifically, the server performs mathematical derivation of the dynamic relationships in the two transfer models, and performs equivalent transformation and simplification of the power response relationship, enabling the frequency response power to be decomposed into power response components caused by rotor speed control and guide vane opening control. Through the derivation of the above power response relationship, the server obtains auxiliary variables to describe the unit's power response characteristics. These auxiliary variables characterize the unit's dynamic response characteristics under the influence of rotor speed regulation and guide vane opening regulation, providing a foundation for subsequent control decoupling of the linearized frequency response model.

[0044] In one embodiment, the transfer functions (fourth transfer model and fifth transfer model) of the frequency power response of the variable speed pumped-storage unit with respect to the guide vane opening power command and the rotor speed power command are respectively solved as follows: (9) (10) in, This is the transfer function of the frequency response power of the variable-speed pumped-storage unit with respect to the rotor speed power command. This is the transfer function of the frequency response power of the variable-speed pumped-storage unit with respect to the guide vane opening power command. This is the linearized transfer function of rotor speed versus mechanical power for a variable-speed pumped-storage unit. This is the linearized transfer function of electromagnetic power versus rotor speed for a variable-speed pumped-storage unit. This is the linearized transfer function of mechanical power to rotor speed for a variable-speed pumped-storage unit.

[0045] By further simplifying formulas (9) and (10), we can obtain the auxiliary variables. A w , B w , C w for: (11) (12) (13) in: This refers to the initial rotor speed of the variable-speed pumped-storage unit. H v The inertial constant of the variable speed pumped-storage unit. D v This is the damping coefficient of the variable speed pumped storage unit. This is the linearized transfer function of the mechanical power of the variable-speed pumped-storage unit with respect to the initial operating point. This is the linearized transfer function of electromagnetic power to rotor speed for a variable-speed pumped-storage unit.

[0046] S103: Decouple the linearized frequency response model using the auxiliary variables, and construct the rotor speed controller and guide vane opening controller respectively; Specifically, the server separates the guide vane opening control and rotor speed control in the linearized frequency response model using auxiliary variables. This allows the power support in the unit's frequency response to be decomposed into the power response generated by rotor speed regulation and the power response generated by guide vane opening regulation. After decoupling, the server establishes corresponding control structures. The rotor speed controller adjusts the rotor speed according to frequency changes to release or absorb rotor kinetic energy, while the guide vane opening controller changes the unit's mechanical power output by adjusting the guide vane opening. This forms two independent but synergistic control links.

[0047] Figure 4 This is a schematic diagram of the fourth process of the frequency regulation control method for variable speed pumped storage units provided in this embodiment of the invention, as shown below. Figure 4 As shown, in one embodiment of the present invention, S103 includes: S401: Decouple the guide vane opening control and rotor speed control in the linearized frequency response model using the auxiliary variables to obtain the rotor speed control frequency response model and the guide vane opening control frequency response model. Specifically, after obtaining the auxiliary variables, the server reconstructs the power response relationship in the linearized frequency response model, separating the control actions originally coupled within the same frequency response relationship. By introducing auxiliary variables to perform an equivalent transformation on the power response relationship, the server decomposes the unit's frequency response power into frequency response power components generated by rotor speed regulation and frequency response power components generated by guide vane opening regulation, thus obtaining frequency response models corresponding to the two control actions respectively. Through this decoupling process, rotor speed regulation and guide vane opening regulation can be made independent of each other in model structure, thereby facilitating the separate design and analysis of different regulation methods.

[0048] S402: Construct a rotor speed controller based on the rotor speed control frequency response model; Specifically, the server models and designs the rotor speed control system based on the dynamic relationship between rotor speed regulation and the unit's frequency response power, enabling the rotor speed to be dynamically adjusted according to changes in system frequency. When a frequency disturbance occurs in the system, the rotor speed controller releases or absorbs rotor kinetic energy by adjusting the unit's rotor speed, thereby rapidly changing the unit's output power to achieve a rapid response to system frequency disturbances.

[0049] S403: Construct a guide vane opening controller based on the guide vane opening control frequency response model.

[0050] Specifically, the server models and designs the guide vane opening control system based on the impact of guide vane opening adjustment on the unit's mechanical power output. This allows the guide vane opening to be adjusted according to frequency changes, thereby altering the unit's mechanical power output. When the system frequency changes, the guide vane opening controller adjusts the guide vane opening to change the turbine's hydraulic power input, achieving continuous regulation of the unit's output power. By constructing separate rotor speed controllers and guide vane opening controllers, the two adjustment methods can be made independent in terms of control structure, providing a foundation for subsequent coordinated control.

[0051] In one embodiment, by introducing auxiliary variables, the coupled control of the guide vane opening and rotor speed of the variable-speed pumped storage unit is achieved. After decoupling, the control of the guide vane opening and rotor speed of the pumped storage unit is as follows: Figure 15 As shown, the frequency support expressions provided by the decoupled guide vane opening control and rotor speed control (rotor speed control frequency response model and guide vane opening control frequency response model) are as follows: (14) (15) in: Electromagnetic power support for the speed control of variable-speed pumped-storage units, Δ P e,YElectromagnetic power support for the guide vane opening control of variable speed pumped storage units, Δ P Y The mechanical power provided by the guide vane opening controller s For the Laplace operator.

[0052] Electromagnetic power support from speed control of variable-speed pumped-storage units refers to the power change input to the system from the variable-speed pumped-storage unit caused solely by the speed change brought about by the speed controller after a disturbance event.

[0053] Electromagnetic power support from guide vane opening control of variable speed pumped storage units refers to the power change input to the system from the variable speed pumped storage unit caused solely by the change in guide vane opening due to the guide vane opening controller after a disturbance event.

[0054] Decoupling control decouples the guide vane opening control and rotor speed control in variable speed pumped storage units, avoiding the difficulty in analyzing the frequency regulation characteristics due to the interweaving of the two controls, and allowing the two frequency regulation resources to participate independently in the system frequency response.

[0055] Therefore, the variable-speed pumped-storage unit is designed to change the guide vane opening through a speed governor, thereby altering the unit's output mechanical power. The guide vane opening controller is designed as follows: Figure 16 As shown, the specific expression is: (16) in: T G The delay time constant of the guide vane servo system. T R The integral time for guide vane opening control. T w The water hammer time constant is... R p This is the permanent droop coefficient for the guide vane opening controller. R T This represents the transient droop coefficient of the guide vane opening controller. f This refers to the system frequency deviation. From the expression (16) of the guide vane opening controller of the variable speed pumped storage unit, it can be seen that since the adjustment of the guide vane opening is a mechanical process, the servo system needs to adjust the guide vane position. At the same time, the change of the guide vane will cause the change of water flow in the pumped storage unit's water intake pipeline, thereby triggering the water hammer effect and causing the phenomenon of power reversal.

[0056] For the rotor kinetic energy stored in the converter of a variable-speed pumped-storage unit, it is desirable to rapidly release or absorb the rotor kinetic energy during the initial control phase, when frequency deviation and rate of frequency change are both large, in the early stages of a frequency event to improve the minimum frequency and rate of frequency change. Therefore, the rotor speed controller, such as... Figure 17As shown, the specific expression is: (17) in: k droop This refers to the droop control coefficient of the rotor speed controller for a variable-speed pumped storage unit. k iner This refers to the inertial control coefficient of the rotor speed controller for a variable-speed pumped storage unit.

[0057] The rotor speed controller rapidly changes the rotor speed through droop control and inertia control, releasing or absorbing rotor kinetic energy to provide frequency support. The guide vane opening controller adjusts the guide vane opening through the speed governor to change the power output of the variable speed pumped storage unit.

[0058] After a frequency event occurs, the rotor speed controller of the variable speed pumped storage unit immediately releases or absorbs rotor kinetic energy to respond to the system frequency by adjusting the opening degree through droop control and inertia control.

[0059] After a frequency change occurs, the guide vane opening controller of the variable speed pumped storage unit changes the guide vane opening position through transient and permanent drooping, thereby changing the output mechanical power of the variable speed pumped storage unit and supporting the system frequency.

[0060] S104: Generate a coordinated control strategy based on the rotor speed controller and the guide vane opening controller to perform frequency regulation control on the variable speed pumped storage unit.

[0061] Specifically, the server comprehensively considers the rapid dynamic response capability of rotor speed regulation and the wide-range power regulation capability of guide vane opening regulation, and coordinates the control actions of the two controllers. This ensures that rotor speed regulation primarily provides rapid, short-term frequency support, while guide vane opening regulation primarily provides continuous power regulation. By constructing a coordinated control strategy, the advantages of the two regulation methods can be complemented, thereby improving the frequency regulation capability of the variable-speed pumped storage unit when frequency disturbances occur in the system, and enhancing the overall performance of the unit in participating in grid frequency control.

[0062] Figure 5 This is a schematic diagram of the fifth process of the frequency regulation control method for variable speed pumped storage units provided in this embodiment of the invention, as shown below. Figure 5 As shown, in one embodiment of the present invention, S104 includes: S501: Based on the rotor speed controller and the guide vane opening controller, Bode plot analysis is performed to obtain the frequency modulation characteristics and effective frequency modulation range of the guide vane opening control and the frequency modulation characteristics and effective frequency modulation range of the rotor speed control. Specifically, the server analyzes the frequency response characteristics of the rotor speed controller and the guide vane opening controller. By constructing the frequency response functions of the corresponding control elements and calculating the amplitude-frequency and phase-frequency characteristics of the control system within different frequency ranges, the dynamic response characteristics of the control system under different frequency disturbance conditions are obtained. Through analysis of the amplitude-frequency and phase-frequency curves, the server can identify the characteristic of faster dynamic response capability of rotor speed control under high-frequency disturbances, and the characteristic of stronger power regulation capability of guide vane opening control within lower frequency ranges. Through the above analysis process, the server determines the frequency modulation range in which rotor speed control and guide vane opening control can exert their advantages, and obtains the frequency modulation characteristics of the two control methods under different frequency disturbance conditions.

[0063] S502: Generate a coordinated control strategy based on the frequency modulation characteristics and effective frequency modulation range of the guide vane opening control and the frequency modulation characteristics and effective frequency modulation range of the rotor speed control.

[0064] Specifically, the server coordinates the frequency regulation control of the unit based on the adjustment capabilities of the two control methods within different frequency ranges. This design prioritizes rotor speed regulation for rapid response to system frequency changes, providing short-term frequency support, while guide vane opening regulation is primarily used for wider and continuous power regulation to maintain stable unit output power. This coordinated control strategy allows the rapid dynamic response of rotor speed regulation to complement the wide-range power regulation of guide vane opening regulation, thereby improving the overall response performance of the variable-speed pumped storage unit when participating in grid frequency regulation.

[0065] In one embodiment, the coordinated control of the guide vane opening and rotor speed of the variable speed pumped storage unit is based on the Bode plot frequency modulation characteristic analysis of the guide vane opening controller and the speed controller. By plotting the response function Bode plots of the guide vane opening and rotor speed of the variable speed pumped storage unit, it can be found that the guide vane opening controller mainly responds to low-frequency load fluctuations, while the rotor speed mainly responds to high-frequency load waveforms. This indicates that the response speed of the guide vane opening controller is relatively slow, while the response speed of the rotor speed controller is rapid.

[0066] By combining Bode plot analysis with the frequency regulation mechanism of variable speed pumped storage units, it can be found that the guide vane opening control of variable speed pumped storage units has the characteristics of slow response speed but wide adjustment range, while the rotor speed has the characteristics of fast response speed but limited adjustment range. Through the coordinated control of the two, the frequency speed and frequency adjustment range of variable speed pumped storage units can be effectively improved.

[0067] The main response ranges of the guide vane opening controller and rotor speed controller are analyzed using Bode plot analysis. Based on the Bode plot curves, the frequency response characteristics of the guide vane opening controller and rotor speed controller are analyzed. The Bode plot curves of the guide vane opening controller and rotor speed control for variable-speed pumped storage are shown below. Figure 18 As shown.

[0068] from Figure 18 As can be seen from the Bode plot amplitude, the proposed decoupling control method enables the variable-speed pumped storage unit to simultaneously possess both high-frequency and low-frequency response capabilities. This demonstrates that the proposed decoupling control method overcomes the limitations imposed by traditional control methods on the variable-speed pumped storage unit's ability to provide rapid frequency support, thereby improving the unit's flexibility in frequency response.

[0069] from Figure 18 The Bode plot shown reveals that the guide vane opening controller exhibits a larger response amplitude in the low-frequency range, while the rotor speed controller has a larger response amplitude in the high-frequency range. This indicates that the guide vane opening controller is more effective and sensitive to low-frequency disturbances, while the rotor speed controller is more effective and sensitive to high-frequency disturbances. This is because the guide vane opening controller typically adjusts the guide vane opening through a servo system, a relatively slow mechanical adjustment process, while rotor speed regulation rapidly releases rotor kinetic energy to support frequency through droop control and inertia control, a fast electrical process.

[0070] In one embodiment, a variable-speed pumped-storage unit coordinated frequency controller is constructed, consisting of long-term frequency support for guide vane opening and short-term frequency support for rotor speed, to take into account both the long-term and short-term frequency support requirements of the power system.

[0071] The established method for coordinated control of guide vane opening and rotor speed in a variable-speed pumped-storage unit is designed based on the analyzed frequency modulation characteristics of the guide vane opening controller and rotor speed controller. The established method for coordinated control of guide vane opening and rotor speed in a variable-speed pumped-storage unit is as follows: Figure 19 As shown, the specific expression is: (18) Where, Δ P V (t) represents the frequency regulation response power of the variable speed pumped storage unit. This refers to the release of kinetic energy by the rotor when the speed of the variable-speed pumped-storage unit changes to the maximum power tracking speed at the current guide vane opening. This refers to the kinetic energy released by the rotor when the speed of the variable-speed pumped-storage unit changes to the maximum rotor speed at the current guide vane opening. This represents the upper limit of the rotor speed of the variable-speed pumped-storage unit. This refers to the rotor speed corresponding to the maximum power tracking point of the variable speed pumped-storage unit at the current guide vane opening. The rotor speed of the system after the variable speed pumped storage unit is supported by the rotor speed alone.

[0072] The criterion in formula (18) is that after the rotor speed releases kinetic energy to participate in frequency regulation, the change in rotor speed of the variable speed pumped storage unit can be calculated by the principle of energy conservation: (19) in, J represents the power support amount corresponding to the rotor kinetic energy released by the variable speed pumped storage unit by reducing the rotor speed after a frequency disturbance. V Let be the rotational mass constant of the variable speed pumped storage unit. This refers to the rotor speed of the variable speed pumped storage unit before the disturbance occurs.

[0073] After a disturbance in the speed response system, if the rotor speed is lower than the rotor speed under the maximum power point tracking (MPPT) at the current guide vane opening, the guide vane opening is adjusted downwards to reduce the unit speed along the MPPT curve. When the rotor speed exceeds the upper speed limit, the rotor speed is adjusted to the maximum power point to absorb the maximum rotor kinetic energy for power support, and the guide vane opening is further adjusted to ensure that the output power of the variable speed pumped storage unit meets the system power balance. When the rotor speed is at the rotor speed of the maximum power point and the upper speed limit, only the rotor speed is adjusted for frequency support.

[0074] The coordinated control method of guide vane opening and rotor speed of variable speed pumped storage units can effectively achieve coordination between long-term power support of guide vane opening and rapid frequency support of rotor speed.

[0075] Figure 6 This is a schematic diagram of the sixth process of the frequency regulation control method for variable speed pumped storage units provided in this embodiment of the invention, as shown below. Figure 6 As shown, in one embodiment of the present invention, the frequency regulation control method for variable speed pumped storage units further includes: S601: When a frequency disturbance occurs in the power grid, the corresponding control method is determined from the coordinated control strategy based on the obtained rotor speed of the unit after responding to the frequency disturbance. Specifically, when the power system experiences load changes or fluctuations in renewable energy output, the grid frequency shifts. The server monitors the unit's operating status during the frequency disturbance response process and acquires information on rotor speed changes during power support. Based on these rotor speed changes, the server determines the unit's current operating status and, in conjunction with pre-set adjustment rules in the coordinated control strategy, selects the appropriate control method within different rotor speed ranges. For example, when the rotor speed change falls within a certain operating range, the server selects a control method primarily based on rotor speed regulation; when the rotor speed change reaches another operating range, the server selects power regulation by adjusting the guide vane opening; within a specific operating range, power regulation can also be achieved through a combination of rotor speed regulation and guide vane opening adjustment. Through these methods, the server can dynamically select a control method suitable for the current operating status based on the unit's speed changes during the disturbance response process.

[0076] S602: The guide vane opening and rotor speed of the variable speed pumped storage unit are controlled in a coordinated manner according to the control method described above.

[0077] Specifically, the server sends control commands to release or absorb rotor kinetic energy by adjusting the rotor speed, thereby achieving a rapid response to changes in system frequency. Simultaneously, it adjusts the guide vane opening to change the turbine's hydraulic input power, thus regulating the unit's output power. Through the synergistic effect of rotor speed regulation and guide vane opening regulation, a combination of rapid power response and continuous power regulation can be achieved when the system frequency changes. This enhances the variable-speed pumped storage unit's ability to participate in grid frequency regulation and ensures stability and regulation efficiency during unit operation.

[0078] In one embodiment, such as Figure 19 As shown, the coordinated control method of guide vane opening and rotor speed of variable speed pumped storage unit can be divided into three control situations according to the rotor speed state of the unit after frequency disturbance.

[0079] Scenario 1: Adjust the guide vane opening upwards ( When system disturbances increase, the unit releases rotor kinetic energy by reducing rotor speed to cope with system power deficits. If, after responding to the disturbance, the unit's rotor speed falls below the rotor speed corresponding to the unit's maximum power output at the current guide vane opening, the guide vane opening (GVO) needs to be adjusted upwards to meet the system frequency response (FR) command. Simultaneously, the rotor speed needs to be maintained near the optimal speed to avoid a secondary frequency drop after frequency support.

[0080] Scenario 2: Rotor speed adjustment ( When a disturbance occurs in the system, the unit first provides power support by changing the rotor speed. If the rotor speed after the disturbance response is between the maximum power speed corresponding to the current guide vane opening and the unit's maximum speed, the power fluctuation can be absorbed or released simply by adjusting the rotor speed without adjusting the guide vane opening. When the system power disturbance is negative, the rotor kinetic energy can be released to participate in frequency support by reducing the rotor speed; when the system power disturbance is positive, the excess energy can be absorbed by increasing the rotor speed.

[0081] Scenario 3: Adjust the guide vane opening downwards ( When system disturbances decrease and the unit needs to absorb power, the unit increases its rotor speed to absorb rotor kinetic energy for power regulation. When the rotor speed after the disturbance response exceeds the maximum allowable speed limit of the unit, the guide vane opening needs to be adjusted downwards to meet the system frequency response requirements. At the same time, the rotor speed needs to be kept near the maximum allowable speed in order to absorb as much rotor kinetic energy as possible and participate in frequency regulation.

[0082] In one embodiment, a schematic diagram of the overall flow of frequency regulation control for a variable-speed pumped storage unit is shown below. Figure 20 As shown.

[0083] In one embodiment, to verify the effectiveness of the proposed frequency control method for coordinating the guide vane opening and rotor speed in variable-speed pumped storage, a guide vane opening controller and rotor speed controller designed based on the variable speed design are constructed as follows: Figure 21 The power system frequency response model containing variable speed pumped storage units is shown in Table 1. The power system parameters are shown in Table 2. Two simulation examples are designed: load surge and clean energy output fluctuation. The frequency response of the variable speed pumped storage units under the proposed coordinated control method and the traditional control method are compared.

[0084] Table 1

[0085] Table 2

[0086] Example 1: In t A step load disturbance of 0.05 pu occurs at 6s. The starting operating point of the variable-speed pumped storage unit is set at the maximum power operating point, with an initial water flow of 0.9 pu and an initial rotor speed of 0.98 pu. The dynamic response of the system is compared under the following two control strategies: Method 1, which coordinates the guide vane opening and rotor speed control; and Method 2, the traditional maximum power point tracking control mode for variable-speed pumped storage units. The system frequency response curve and the guide vane opening change curve of the variable-speed pumped storage unit are shown below. Figure 22 As shown.

[0087] like Figure 22 As shown in section (a), when the proposed coordinated control strategy for guide vane opening and rotor speed is applied to the variable-speed pumped storage unit (VSPS), the maximum frequency deviation is -0.068 pu, and the steady-state time is 6.2 s. Under the conventional maximum power point tracking method, the maximum frequency deviation of the system is -0.1 pu, the steady-state time is 15.3 s, and the system experiences a secondary frequency drop with an amplitude of -0.001 pu. Figure 22 As shown in part (b), the guide vane opening increases by -0.0156 pu under the proposed coordinated control strategy, while the guide vane opening is not adjusted under the maximum power point tracking control mode. The simulation results demonstrate that the proposed coordinated control method can effectively improve the frequency regulation capability of variable speed pumped storage units by adjusting the guide vane opening and rotor speed, showing a significant improvement in frequency regulation performance compared to traditional control methods.

[0088] Example 2: A fluctuating wind speed is applied to the system. The variable-speed pumped-storage unit is set to start at its maximum power operating point, with an initial water flow rate of 0.9 pu and an initial rotor speed of 0.98 pu. The dynamic response of the system is compared under the following two control strategies: Method 1, which coordinates the guide vane opening and rotor speed control; and Method 2, the traditional maximum power tracking control mode for variable-speed pumped-storage units. After 500 seconds of operation, the system frequency response curve and the guide vane opening change curve of the variable-speed pumped-storage unit are shown below. Figure 23 As shown.

[0089] like Figure 23 Part (a) shows the frequency fluctuation curve of a system containing variable-speed pumped storage under fluctuating wind power. Under the traditional maximum power point tracking control strategy, the frequency fluctuation range of the system is [-6×10]. -3 PU, 5.8×10 - 3 Under the proposed coordinated control strategy, the system frequency fluctuation range is [-3.85×10]. -3 PU, 3.95×10 -3 The value of pu is significantly smaller than that of the traditional control strategy, which proves that the proposed coordinated control strategy can effectively improve the frequency regulation capability of the variable speed pumped storage unit. Figure 23 Part (b) shows the adjustment curve of the guide vane opening during the operation of the variable-speed pumped storage system. In traditional control, the guide vane opening frequency operation has a maximum adjustment range of -8 × 10⁻⁶. -3 pu, while the maximum change in guide vane opening under the proposed coordinated control strategy is 1×10 -4The results demonstrate that the proposed coordinated control strategy can effectively utilize rotor kinetic energy for frequency modulation, thereby reducing the number of guide vane opening adjustments. This shows that the proposed control strategy effectively leverages the complementary advantages of guide vane opening adjustment and rotor adjustment in variable-speed pumped storage. When small, frequent disturbances occur in the system, frequency support is provided by adjusting the rotor speed; guide vane opening adjustment is only performed when large power disturbances occur, effectively avoiding mechanical wear caused by frequent guide vane opening adjustments.

[0090] This application provides a frequency regulation control method for a variable-speed pumped storage unit. The method involves constructing a linearized frequency response model of the variable-speed pumped storage unit based on acquired unit operating parameters; generating auxiliary variables based on the linearized frequency response model; decoupling the linearized frequency response model using the auxiliary variables and constructing a rotor speed controller and a guide vane opening controller; and generating a coordinated control strategy based on the rotor speed controller and the guide vane opening controller to perform frequency regulation control on the variable-speed pumped storage unit. This method effectively utilizes the guide vane opening frequency regulation capability and rotor kinetic energy, fully leveraging the unit's short-term and long-term frequency regulation capabilities, thereby improving the dynamic performance of the system frequency response containing the variable-speed pumped storage unit.

[0091] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0092] Based on the same inventive concept, embodiments of the present invention also provide a frequency regulation control device for a variable-speed pumped-storage unit, which can be used to implement the frequency regulation control method for a variable-speed pumped-storage unit described in the above embodiments, as described in the following embodiments. Since the principle of the frequency regulation control device for a variable-speed pumped-storage unit is similar to that of the frequency regulation control method for a variable-speed pumped-storage unit, embodiments of the frequency regulation control device for a variable-speed pumped-storage unit can be found in embodiments of the frequency regulation control method for a variable-speed pumped-storage unit, and repeated details will not be elaborated further. As used below, the terms "unit" or "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0093] Figure 7 This is a schematic block diagram of the first structure of the frequency regulation control device for a variable speed pumped storage unit provided in an embodiment of the present invention, as shown below. Figure 7 As shown, in one embodiment of the present invention, the variable speed pumped storage unit frequency regulation control device of the present invention includes: Model building unit 701 is used to build a linearized frequency response model of the variable speed pumped storage unit based on the acquired unit operating parameters. Auxiliary variable generation unit 702 is used to generate auxiliary variables based on the linearized frequency response model; The control decoupling unit 703 is used to decouple the linearized frequency response model using the auxiliary variables, and to construct the rotor speed controller and the guide vane opening controller respectively. The control strategy generation unit 704 is used to generate a coordinated control strategy based on the rotor speed controller and the guide vane opening controller to perform frequency regulation control on the variable speed pumped storage unit.

[0094] Figure 8 This is a schematic block diagram of the second structure of the frequency regulation control device for a variable speed pumped storage unit provided in an embodiment of the present invention. Figure 7 Based on the embodiments, further, such as Figure 8 As shown, in one embodiment of the present invention, the model building unit 701 includes: The first model establishment module 801 is used to establish a first transmission model between the change in rotor speed and the change in mechanical power, and a second transmission model between the change in rotor speed and the change in electromagnetic power, based on the unit operating parameters. The second model building module 802 is used to establish a third transmission model between the difference between the mechanical power change and the electromagnetic power change and the rotor speed change based on the obtained unit inertia constant and damping coefficient. The response model construction module 803 is used to construct the linearized frequency response model based on the first transfer model, the second transfer model and the third transfer model.

[0095] Figure 9 This is a schematic block diagram of the third structure of the frequency regulation control device for a variable speed pumped storage unit provided in an embodiment of the present invention. Figure 7 Based on the embodiments, further, such as Figure 9 As shown, in one embodiment of the present invention, the auxiliary variable generation unit 702 includes: The third model building module 901 is used to build a fourth transmission model between rotor speed power command and frequency response power and a fifth transmission model between guide vane opening power command and frequency response power based on the linearized frequency response model. The auxiliary variable generation module 902 is used to derive the auxiliary variable based on the fourth and fifth transfer models.

[0096] Figure 10 This is a schematic block diagram of the fourth structure of the frequency regulation control device for a variable speed pumped storage unit provided in an embodiment of the present invention. Figure 7Based on the embodiments, further, such as Figure 10 As shown, in one embodiment of the present invention, the control decoupling unit 703 includes: The control decoupling module 1001 is used to decouple the guide vane opening control and rotor speed control in the linearized frequency response model using the auxiliary variables, so as to obtain the rotor speed control frequency response model and the guide vane opening control frequency response model. The first controller construction module 1002 is used to construct a rotor speed controller based on the rotor speed control frequency response model. The second controller construction module 1003 is used to construct a guide vane opening controller based on the guide vane opening control frequency response model.

[0097] Figure 11 This is a fifth structural schematic block diagram of the frequency regulation control device for a variable-speed pumped storage unit provided in an embodiment of the present invention. Figure 7 Based on the embodiments, further, such as Figure 11 As shown, in one embodiment of the present invention, the control strategy generation unit 704 includes: The frequency modulation analysis module 1101 is used to perform Bode plot analysis based on the rotor speed controller and the guide vane opening controller to obtain the frequency modulation characteristics and effective frequency modulation range of the guide vane opening control and the frequency modulation characteristics and effective frequency modulation range of the rotor speed control. The control strategy generation module 1102 is used to generate a coordinated control strategy based on the frequency modulation characteristics and effective frequency modulation range of the guide vane opening control and the frequency modulation characteristics and effective frequency modulation range of the rotor speed control.

[0098] Figure 12 This is a sixth structural schematic block diagram of the frequency regulation control device for a variable-speed pumped storage unit provided in an embodiment of the present invention. Figure 7 Based on the embodiments, further, such as Figure 12 As shown, in one embodiment of the present invention, the variable speed pumped storage unit frequency regulation control device of the present invention further includes: The control method determination unit 1201 is used to determine the corresponding control method from the coordinated control strategy based on the obtained rotor speed of the unit after responding to the frequency disturbance when the power grid experiences a frequency disturbance. The collaborative control unit 1202 is used to collaboratively control the guide vane opening and rotor speed of the variable speed pumped storage unit according to the control method.

[0099] This application provides a frequency regulation control method and apparatus for a variable-speed pumped storage unit. The method involves constructing a linearized frequency response model of the variable-speed pumped storage unit based on acquired unit operating parameters; generating auxiliary variables based on the linearized frequency response model; decoupling the linearized frequency response model using the auxiliary variables and constructing a rotor speed controller and a guide vane opening controller; and generating a coordinated control strategy based on the rotor speed controller and the guide vane opening controller to perform frequency regulation control on the variable-speed pumped storage unit. This effectively utilizes the guide vane opening frequency regulation capability and rotor kinetic energy, fully leveraging the unit's short-term and long-term frequency regulation capabilities, thereby improving the dynamic performance of the system frequency response containing the variable-speed pumped storage unit.

[0100] Figure 13 This is a schematic diagram of the structure of the computer device provided in an embodiment of the present invention, such as... Figure 13 As shown, the electronic device may include a processor 1301, a communication interface 1302, a memory 1303, and a communication bus 1304. The processor 1301, communication interface 1302, and memory 1303 communicate with each other via the communication bus 1304. The processor 1301 can call logic instructions in the memory 1303 to execute the following methods: constructing a linearized frequency response model of the variable-speed pumped storage unit based on the acquired unit operating parameters; generating auxiliary variables based on the linearized frequency response model; decoupling the linearized frequency response model using the auxiliary variables and constructing a rotor speed controller and a guide vane opening controller respectively; and generating a coordinated control strategy based on the rotor speed controller and the guide vane opening controller to perform frequency regulation control on the variable-speed pumped storage unit.

[0101] Furthermore, the logical instructions in the aforementioned memory 1303 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, a top-drive control center server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0102] This embodiment discloses a computer program product, which includes a computer program stored on a computer-readable storage medium. The computer program includes program instructions, and when the program instructions are executed by a computer, the computer can execute the methods provided in the above-described method embodiments, such as: constructing a linearized frequency response model of a variable-speed pumped storage unit based on the acquired unit operating parameters; generating auxiliary variables based on the linearized frequency response model; decoupling the linearized frequency response model using the auxiliary variables, and constructing a rotor speed controller and a guide vane opening controller respectively; and generating a coordinated control strategy based on the rotor speed controller and the guide vane opening controller to perform frequency regulation control on the variable-speed pumped storage unit.

[0103] This embodiment provides a computer-readable storage medium storing a computer program that causes the computer to execute the methods provided in the above-described method embodiments. For example, the methods include: constructing a linearized frequency response model of the variable-speed pumped storage unit based on acquired unit operating parameters; generating auxiliary variables based on the linearized frequency response model; decoupling the linearized frequency response model using the auxiliary variables and constructing a rotor speed controller and a guide vane opening controller respectively; and generating a coordinated control strategy based on the rotor speed controller and the guide vane opening controller to perform frequency regulation control on the variable-speed pumped storage unit.

[0104] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0105] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0106] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0107] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0108] In the description of this specification, the references to terms such as "an embodiment," "a specific embodiment," "some embodiments," "for example," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is 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.

[0109] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above descriptions are merely specific embodiments of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A frequency regulation control method for a variable-speed pumped storage unit, characterized in that, include: A linearized frequency response model of the variable speed pumped storage unit was constructed based on the obtained unit operating parameters. Auxiliary variables are generated based on the linearized frequency response model; The linearized frequency response model is decoupled using the auxiliary variables, and a rotor speed controller and a guide vane opening controller are constructed respectively. A coordinated control strategy is generated based on the rotor speed controller and the guide vane opening controller to perform frequency regulation control on the variable speed pumped storage unit.

2. The frequency regulation control method for a variable-speed pumped storage unit according to claim 1, characterized in that, The construction of a linearized frequency response model for the variable-speed pumped storage unit based on the acquired unit operating parameters includes: Based on the unit's operating parameters, a first transmission model between the change in rotor speed and the change in mechanical power, and a second transmission model between the change in rotor speed and the change in electromagnetic power are established. A third transmission model is established based on the obtained unit inertia constant and damping coefficient to establish the relationship between the difference between the mechanical power change and the electromagnetic power change and the rotor speed change. The linearized frequency response model is constructed based on the first transfer model, the second transfer model, and the third transfer model.

3. The frequency regulation control method for a variable-speed pumped storage unit according to claim 1, characterized in that, The generation of auxiliary variables based on the linearized frequency response model includes: Based on the linearized frequency response model, a fourth transmission model between rotor speed power command and frequency response power, and a fifth transmission model between guide vane opening power command and frequency response power are established. The auxiliary variable is derived based on the fourth and fifth transfer models.

4. The variable speed pumped storage plant frequency control method of claim 1, wherein, The step of decoupling the linearized frequency response model using the auxiliary variables and constructing a rotor speed controller and a guide vane opening controller includes: The auxiliary variables are used to decouple the guide vane opening control and rotor speed control in the linearized frequency response model to obtain the rotor speed control frequency response model and the guide vane opening control frequency response model. A rotor speed controller is constructed based on the rotor speed control frequency response model. A guide vane opening controller is constructed based on the guide vane opening control frequency response model.

5. The variable speed pumped storage plant frequency control method of claim 1, wherein, The generation of a coordinated control strategy based on the rotor speed controller and the guide vane opening controller includes: Bode plot analysis was performed based on the rotor speed controller and the guide vane opening controller to obtain the frequency modulation characteristics and effective frequency modulation range of the guide vane opening control and the frequency modulation characteristics and effective frequency modulation range of the rotor speed control. A coordinated control strategy is generated based on the frequency modulation characteristics and effective frequency modulation range of the guide vane opening control and the frequency modulation characteristics and effective frequency modulation range of the rotor speed control.

6. The variable speed pumped storage plant frequency control method of claim 1, wherein, Also includes: When a frequency disturbance occurs in the power grid, the corresponding control method is determined from the coordinated control strategy based on the obtained rotor speed of the unit after the frequency disturbance. The guide vane opening and rotor speed of the variable speed pumped storage unit are controlled in a coordinated manner according to the control method described above.

7. A variable speed pumped storage unit frequency control device, characterized by, include: The model building unit is used to build a linearized frequency response model of the variable speed pumped storage unit based on the acquired unit operating parameters. An auxiliary variable generation unit is used to generate auxiliary variables based on the linearized frequency response model. A control decoupling unit is used to decouple the linearized frequency response model using the auxiliary variables, and to construct a rotor speed controller and a guide vane opening controller respectively. The control strategy generation unit is used to generate a coordinated control strategy based on the rotor speed controller and the guide vane opening controller to perform frequency regulation control on the variable speed pumped storage unit.

8. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program / instructions stored thereon, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the method according to any one of claims 1 to 6.

10. A computer program product comprising computer programs / instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the method according to any one of claims 1 to 6.

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