Quantitative analysis method for stability domain of regulating system of doubly-fed variable-speed pumped storage power station

Abstract

The application discloses a kind of double-fed variable-speed pumped storage power station regulating system stable domain quantitative analysis method, this method is by establishing the fine model of double-fed variable-speed pumped storage power station regulating system, and the stable domain of fine model is simulated and calculated in time domain;By reducing the order to the fine model, the stable domain and the margin domain of the reduced-order model are derived and calculated;The stable margin of reduced-order model is used to quantify the stability domain of fine model.The method disclosed in the application points out the stability difference of the fine model and the reduced-order model of the control system of variable-speed pumped storage power station, which can guide the personnel of variable-speed pumped storage power station to use the reduced-order model to optimize the design of complex system parameter setting and hydraulic and electrical parameters, and improve the accuracy of the results.

Description

Technical Field

[0001] This invention belongs to the technical field of modeling and stability analysis of variable speed pumped storage power stations, and particularly relates to a quantitative analysis method for the stability domain of a doubly fed variable speed pumped storage power station regulation system. Background Technology

[0002] Due to the volatility and randomness of wind and solar power generation, the regulation capabilities of new power systems face new challenges. To address this challenge, pumped storage technology has gradually become one of the important means to solve current problems in new power systems. In recent years, variable-speed pumped storage power stations have become a hot research and application area due to their significant advantages over traditional constant-speed units in terms of operational flexibility, regulation response speed, and system stability.

[0003] Variable-speed pumped storage units can ensure that the pumps and turbines always operate within their high-efficiency range through speed regulation, thereby reducing turbine wear and extending equipment lifespan. Furthermore, by directly regulating power through converters, variable-speed units not only offer rapid response and flexible control but also significantly enhance their grid support capabilities, further promoting the efficient integration of renewable energy. While the synchronous motors of fixed-speed units operate synchronously with the grid, the AC excitation motors in variable-speed units exhibit decoupling from the grid, resulting in lower robustness compared to fixed-speed units. Therefore, variable-speed units may face stability risks when participating in grid peak shaving and frequency regulation, which has become one of the key issues in the current application of variable-speed pumped storage power stations.

[0004] Existing technologies have published relevant research, such as the Chinese patent application CN117691626A, published on March 12, 2024, which discloses a frequency regulation method for a doubly-fed variable-speed pumped storage system. This method constructs a mathematical model of the doubly-fed induction motor and the reversible pump-turbine to obtain the optimal speed as a reference command for the unit's speed. Under power generation and pumping conditions, it combines frequency deviation tuning with additional active power commands to adjust the mechanical guide vane opening and electromagnetic torque, thereby improving the unit's response speed, suppressing frequency change rate and extreme values, and shortening the time to reach steady state. Another example is the Chinese patent application CN117578628A, published on February 20, 2024, which discloses a dynamic frequency regulation method for pumped storage units. This method uses dynamic frequency regulation, acquiring grid frequency changes to determine if they exceed the frequency dead zone. If not, it uses an active power command based on inertial response for regulation; if exceeding, it combines a primary frequency regulation active power command based on droop control to generate a new unit output power command, which is then limited and the grid frequency is adjusted.

[0005] The main shortcomings of existing methods are as follows: some studies, in order to simplify calculations, have highly simplified the electrical or hydraulic sub-models, failing to fully consider the coupling characteristics of multiple physical quantities (water, machinery, and electricity) in variable-speed pumped storage power stations, resulting in inaccurate analysis results of the system's dynamic behavior. Furthermore, although some studies have established relatively detailed hydraulic and electrical side models, these models have certain limitations in their construction methods, making it difficult to deeply reveal the system's intrinsic characteristics from a physical and mathematical perspective.

[0006] Therefore, existing technologies lack research and analysis on the differences in stability analysis between refined and simplified models, making it difficult to reveal the stability of the system and its influencing factors in essence, and failing to provide strong theoretical support for the optimal design and operation control of the system. Summary of the Invention

[0007] To overcome the shortcomings of the prior art, this invention provides a method for quantitative analysis of the stability domain of a doubly-fed variable-speed pumped storage power station regulation system. This method involves establishing a refined model of the doubly-fed variable-speed pumped storage power station regulation system and calculating the stability domain of the refined model using time-domain simulation. By reducing the order of the refined model, the stability domain and margin domain of the reduced-order model are derived and calculated. Finally, the stability domain of the refined model is quantified using the stability margin of the reduced-order model. This effectively reduces the stability calculation time of the doubly-fed variable-speed pumped storage power station regulation system and improves the accuracy of stability calculations.

[0008] According to one aspect of the present invention, a method for quantitative analysis of the stability domain of a doubly-fed variable-speed pumped storage power station regulation system is provided, comprising:

[0009] A refined model of the regulation system of a doubly fed variable speed pumped storage power station is established, and the stability region of the refined model is calculated by time-domain simulation.

[0010] Reduce the order of the refined model and calculate the stability region and margin region of the reduced model;

[0011] Based on the stability margin of the reduced-order model, the stability region of the refined model is quantized.

[0012] As a further technical solution, the stability region of the refined model for time-domain simulation calculation includes:

[0013] Input the internal parameters of the refined model;

[0014] Select the two parameters, proportional gain and derivative gain of the speed governor within the refined model, as a rectangular coordinate system, and input the upper limit of the coordinate axes and the calculation accuracy;

[0015] Initialize the coordinate axis parameters, the number of iterations, and the number of calculations;

[0016] The actual parameters of the doubly fed variable speed pumped storage power station are input into the refined model for time-domain simulation calculation. All points that have not diverged from the simulation calculation are plotted on the rectangular coordinate axis, and the outermost points are connected to obtain the stability region of the refined model.

[0017] As a further technical solution, the refined model can be reduced in order, including:

[0018] The pipeline model was downgraded to a second-order elastic pipeline model, the pump-turbine model was downgraded to a pump-turbine model with six transfer coefficients, and the electrical side model was downgraded to a first-order model.

[0019] As a further technical solution, the stability region and margin region of the reduced-order model are calculated, including:

[0020] The synthetic transfer function is derived based on the reduced-order model;

[0021] The denominator of the comprehensive transfer function is used as the characteristic equation of the variable speed pumped storage power station regulation system.

[0022] When the stability margin domain of the regulating system of the variable speed pumped storage power station is m, the stability characteristic equation of the margin satisfies that the real part of all characteristic roots is less than -m. Let s=Ym to calculate the stability characteristic equation of the margin.

[0023] By applying the Herwitz criterion to the two characteristic equations mentioned above, the stability region and residual region of the reduced-order model are obtained.

[0024] As a further technical solution, based on the stability margin of the reduced-order model, the stability region of the refined model is quantized, including:

[0025] Calculate the margin domain and the area of ​​the margin domain for two models with different stable margins and descent order.

[0026] Calculate the area of ​​the stability region in the refined model;

[0027] Based on the stability region area, margin region, and margin region area mentioned above, the stability margin of the refined model's stability region relative to the reduced-order model is quantified.

[0028] As a further technical solution, the stability margin of the refined model relative to the reduced-order model in the stability region is quantified according to the following expression:

[0029] ,

[0030] In the formula, m1 and m2 represent two different stability margins, and A m1 and A m2 Let A represent the area of ​​the margin domain for two descent-order models with different stable margins. j This represents the area of ​​the stability region in the refined model.

[0031] According to one aspect of the present invention, a stability domain quantitative analysis system for a doubly-fed variable-speed pumped storage power station regulation system is provided, for implementing the method, comprising:

[0032] The first main module is used to establish a refined model of the regulation system of the doubly fed variable speed pumped storage power station and to perform time-domain simulation calculations of the stability domain of the refined model.

[0033] The second main module is used to reduce the order of the refined model and calculate the stability region and margin region of the reduced model.

[0034] The third main module is used to quantize the stability region of the refined model based on the stability margin of the reduced-order model.

[0035] According to one aspect of the present invention, a stability domain quantitative analysis device for a doubly-fed variable-speed pumped storage power station regulation system is provided, comprising a memory and a processor. The memory stores program instructions that are executed by the processor, and the processor invokes the program instructions to execute the stability domain quantitative analysis method for the doubly-fed variable-speed pumped storage power station regulation system.

[0036] According to one aspect of the present invention, a non-transitory computer-readable storage medium is provided, the non-transitory computer-readable storage medium storing computer instructions that cause the computer to execute the described method for quantitative analysis of the stability domain of a doubly-fed variable-speed pumped storage power station regulation system.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] This invention presents a quantitative analysis method for the stability domain of a doubly-fed variable-speed pumped storage power station regulation system. This method can effectively reduce the stability calculation time of the doubly-fed variable-speed pumped storage power station regulation system and improve the accuracy of stability calculation. It can effectively guide personnel of variable-speed pumped storage power stations to use reduced-order models to tune complex system parameters and optimize the design of hydraulic and electrical side parameters, and improve the accuracy of the results. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying 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.

[0040] Figure 1 This is a schematic diagram of the stability domain quantification analysis method for a doubly fed variable speed pumped storage power station regulation system provided in an embodiment of the present invention.

[0041] Figure 2This is a schematic diagram of the stability domain calculation process for a refined model of a variable-speed pumped storage power station regulation system provided in an embodiment of the present invention.

[0042] Figure 3 This is a schematic diagram of a refined model of a variable-speed pumped storage power station regulation system provided in an embodiment of the present invention;

[0043] Figure 4 This is a schematic diagram of the stability region of the refined and reduced-order model of the regulating system of the variable-speed pumped storage power station provided in an embodiment of the present invention;

[0044] Figure 5 This is a schematic diagram of the stability domain and the margin domain (m=0.1) of the reduced-order model of the regulating system of a variable-speed pumped storage power station provided in an embodiment of the present invention. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. In addition, the technical features of the various embodiments or individual embodiments provided by the present invention can be arbitrarily combined to form new technical solutions. Such combinations are not bound by the order of steps and / or structural composition patterns, but must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0046] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices. The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be decomposed, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0047] This invention provides a method for quantitative analysis of the stability domain of a doubly-fed variable-speed pumped storage power station regulation system, such as... Figure 1As shown, firstly, a refined model of the doubly fed variable speed pumped storage power station regulation system is established, and the stability region of the refined model is calculated by time-domain simulation; then, the refined model is reduced in order, and the stability region and margin region of the reduced-order model are calculated; subsequently, based on the stability margin of the reduced-order model, the stability region of the refined model is quantified.

[0048] This invention presents a method for quantitatively analyzing the stability domain of a doubly-fed variable-speed pumped storage power station regulation system. It establishes a refined model of the regulation system and calculates the stability domain of the refined model using time-domain simulation. By reducing the order of the refined model, the stability domain and margin domain of the reduced-order model are derived and calculated. Furthermore, a method is proposed to quantify the stability domain of the refined model using the stability margin of the reduced-order model. This method effectively reduces the stability calculation time of the doubly-fed variable-speed pumped storage power station regulation system and improves the accuracy of stability calculations.

[0049] The specific process of the stability domain quantification analysis method for the doubly-fed variable-speed pumped storage power station regulation system described in this embodiment of the invention is as follows:

[0050] Step 1: Establish a refined model of the regulation system of the doubly fed variable speed pumped storage power station, and perform time-domain simulation to calculate the stability region of the refined model.

[0051] This embodiment assumes that the variable-speed pumped storage system is connected to the grid and the system frequency is maintained constant by an infinite power grid. Only the actual active power generated by the system and the rotational speed of the pumped storage system need to be controlled.

[0052] In the virtual simulation system, the variable speed pumped storage power station operates in grid-connected mode, and the control mode adopts the power priority control mode, that is, the converter controls the power and the speed governor controls the speed.

[0053] Step 1 involves establishing a refined model of the doubly-fed variable-speed pumped storage power station's regulation system, which further includes:

[0054] S1.1, Establish the hydraulic mathematical model: The transfer function method is used to establish the model of the governor, the characteristic line method is used to establish the model of the pressurized pipeline and the surge chamber, and the improved Suter curve method is used to perform interpolation modeling of the pump turbine.

[0055] S1.2: Establish the mathematical model of the electrical side: Establish the AC excitation motor model based on the state-space equation, and establish the converter model based on the transfer function method.

[0056] Based on the constructed subsystem model, the final regulation system model is as follows: Figure 3 As shown in the figure. For the mechanical speed of the unit, For a given rotational speed, For the torque of the water pump and turbine, For the power grid frequency, For grid / stator voltage, For rotor control voltage, For stator active power, For stator reactive power, For rotor current, For a given active power, Given the stator reactive power.

[0057] In step 1, the time-domain simulation calculation of the stability region of the refined model further includes:

[0058] S1.3: Input the internal parameters of the model, including the control parameters of the PI speed controller, pipe length, pipe diameter, main servo time constant, AC excitation motor controller parameters, stator and rotor resistance and inductance, etc.

[0059] S1.4: Select the proportional gain of the speed controller within the model. K p and differential gain K i The two parameters form a Cartesian coordinate system, and the upper limit of the coordinate axis x is input. x y y And the calculation precision ε, such as x x =10, y y =10, calculation accuracy ε=0.01.

[0060] S1.5: Define the initial x and y axis parameters as 0, the number of replacements n=0, and the number of calculations i=0.

[0061] S1.6: Input the actual parameters of the doubly-fed variable-speed pumped storage power station into the refined model for time-domain simulation calculation. The specific calculation process is as follows: Figure 2 As shown.

[0062] Figure 2 When performing time-domain simulation calculations, if the calculated points diverge, it is necessary to determine whether the y-axis coordinate is less than its upper limit y. y If so, then further determine whether the number of replacements n is equal to 0. If so, update the x-axis coordinate x with the calculation precision ε. i If the condition is not met, return S1.5; otherwise, update y0 with the calculation precision ε and return S1.5.

[0063] Furthermore, if the y-axis coordinate is determined to be greater than or equal to its upper limit y... y The calculation ends when the condition is met.

[0064] Furthermore, if the calculated points do not diverge, the x-axis coordinates are updated with the calculation precision ε. i The number of iterations increases, and the process returns to perform time-domain simulation calculations for the next point.

[0065] S1.7: Plot all the points that have not diverged from the refined simulation on the Cartesian coordinate axis, and connect the outermost points to obtain the stability region of the refined model.

[0066] Step 2: Refine the model by reducing its order, and derive and calculate the stability region and margin region of the reduced-order model.

[0067] Step 2, the refinement of the model order reduction further includes:

[0068] The pipeline model (i.e., the aforementioned pressurized pipeline and surge tank models) was downgraded to a second-order elastic pipeline model, the pump-turbine model was downgraded to a pump-turbine model using six transfer coefficients, and the electrical side model was downgraded to a first-order model. This step did not downgrade the governor model.

[0069] The parameters of the reduced-order model are obtained using the following formula:

[0070] ,

[0071] In the formula, T w It is the inertial time constant of the water flow. T e It is the elastic time constant of water flow. Q r The rated flow rate of the water pump and turbine is g, where g is the acceleration due to gravity. h It's water head. L It is the length of the pipe. S It is the cross-sectional area of ​​the pipe. v It is the pressure propagation velocity within the pressure pipeline. It should be noted that the parameter input for the refined model is the actual parameters of the doubly-fed variable-speed pumped storage power station. The parameter input for the reduced-order model is obtained by calculating the actual parameters of the doubly-fed variable-speed pumped storage power station using the above formulas (1) and (2) and then inputting them.

[0072] Step 2, deriving and calculating the stability region and margin region of the reduced-order model, further includes:

[0073] S2.1: Derive the synthetic transfer function based on the model order reduction of the refined model.

[0074] S2.2: The denominator of the comprehensive transfer function is taken as the characteristic equation of the variable-speed pumped storage power station regulation system, as shown in equation (3), where s It is the Laplace operator. a n yes s of n The coefficient of the power;

[0075] ,

[0076] S2.3: The stability margin range of the regulating system of a variable-speed pumped storage power station is... m At that time, the stable characteristic equation of the remainder must satisfy that the real parts of all characteristic roots are less than -1. m ,make s = Y - m The calculated residual stability characteristic equation is shown in equation (4), which is expanded to obtain equation (5), where c n The coefficients are obtained by expanding the coefficients in equation (4) and combining like terms. Among them, Y is a new variable introduced by variable substitution, which helps to construct the residual stability characteristic equation so that the stability residual of the system can be studied by analyzing the equations (equations (4) and (5)) related to Y.

[0077] ,

[0078] It should be noted that the stable margin domain refers to a specific region with stability margin characteristics obtained after performing quantitative analysis on the model's stable domain using the margin domain calculation method.

[0079] S2.4: Selecting a stability margin m=0.1, the stability region and margin region of the reduced-order model are obtained by applying the Herwitz criterion to equations (3) and (5) respectively, as follows: Figure 5 As shown. The Herwitz criterion described in this step adopts existing technology, wherein the stability region is calculated using the Herwitz criterion formula (3), the margin region is calculated using the Herwitz criterion formula (5), and the stability margin region m can be set by the user.

[0080] Step 3: Quantize the stability margin of the reduced-order model to refine the model's stability domain.

[0081] S3.1: Calculate the margin domains for the descent-order models with different stability margins, obtaining the margin domains for two stability margins, m1 and m2. The margin domain of m1 completely encloses the stability domain of the refined model, while the margin domain of m2 is completely enclosed by the stability domain of the refined model. For example... Figure 4 The figure shows the margin domain with m1=0.01 and m2=0.10. In this step, the margin domain is obtained by using the Herwitz criterion (5), and the stable margins m1 and m2 are set by the user.

[0082] S3.2: Calculate the margin domain area A of the stability margins m1 and m2 in the reduced-order model. m1 and A m2 Calculate the area A of the stability region of the refined model. j .like Figure 4 As shown, A m1 =6.427, A m2 =1.925, A j =4.956.

[0083] In this step, the area A of the residual domain m1 and A m2 and the area of ​​the stability region A j The area is obtained by integrating the region enclosed by the coordinate axes and the Herwitz criterion calculation from the previous step.

[0084] S3.3: Define the stability margin m of the quantized refined model relative to the reduced-order model in the stability region. j =0.0653, as shown in equation (6).

[0085] ,

[0086] Among them, the margin domain of the stability margin m1 of the reduced-order model completely surrounds the stability domain of the refined model, and the margin domain of m2 is completely surrounded by the stability domain of the refined model; A m1 and A m2 A is the area of ​​the margin domain under the stability margins m1 and m2 of the reduced-order model. j It is the area of ​​the stability region of the refined model.

[0087] The implementation of the various embodiments of the present invention is based on programmed processing by a device with processor functionality. Therefore, in practical engineering, the technical solutions and functions of the various embodiments of the present invention are encapsulated into various modules. Based on this reality, and building upon the above embodiments, the embodiments of the present invention provide a stability domain quantification analysis system for a doubly-fed variable-speed pumped storage power station regulation system. This system is used to execute the stability domain quantification analysis method for a doubly-fed variable-speed pumped storage power station regulation system in the above method embodiments.

[0088] The system includes: a first main module, used to establish a refined model of the doubly fed variable speed pumped storage power station regulation system and to perform time-domain simulation to calculate the stability domain of the refined model; a second main module, used to reduce the order of the refined model and calculate the stability domain and margin domain of the reduced-order model; and a third main module, used to quantify the stability domain of the refined model based on the stability margin of the reduced-order model.

[0089] The stability domain quantification analysis system for a doubly-fed variable-speed pumped storage power station regulation system provided in this invention addresses the current situation where existing technologies lack research and analysis on the differences in stability analysis between refined and simplified models, making it difficult to fundamentally reveal the system's stability and its influencing factors, and failing to provide strong theoretical support for the system's optimized design and operation control. This system employs several modules to establish a refined model of the doubly-fed variable-speed pumped storage power station regulation system, calculate the stability domain of the refined model using time-domain simulation, derive and calculate the stability domain and margin domain of the reduced-order model by reducing the order of the refined model, and quantify the stability domain of the refined model using the stability margin of the reduced-order model. This effectively reduces the stability calculation time of the doubly-fed variable-speed pumped storage power station regulation system and improves the accuracy of stability calculations.

[0090] It should be noted that the system embodiments provided by the present invention are used not only to implement the methods in the above method embodiments, but also to implement the methods in other method embodiments provided by the present invention. The only difference is that corresponding functional modules are set. The principle is basically the same as that of the above system embodiments provided by the present invention. As long as those skilled in the art can improve the modules in the above system embodiments by referring to the specific technical solutions in other method embodiments and combining technical features to obtain corresponding technical means and technical solutions composed of these technical means, on the basis of the above system embodiments, and on the premise of ensuring the practicality of the technical solutions, they can obtain corresponding system-like embodiments for implementing the methods in other method-like embodiments.

[0091] Based on the same inventive concept as any of the foregoing embodiments, this embodiment of the invention also provides a stability domain quantitative analysis device for a doubly-fed variable-speed pumped storage power station regulation system, including a memory and a processor. The memory stores program instructions that are executed by the processor, and the processor calls the program instructions to execute the stability domain quantitative analysis method for the doubly-fed variable-speed pumped storage power station regulation system.

[0092] In embodiments of the present invention, the memory can be non-volatile memory, such as a hard disk drive (HDD) or a solid-state drive (SSD), or it can be volatile memory, such as random-access memory (RAM). Memory is any other medium capable of carrying or storing desired program code having an instruction or data structure form and accessible by a computer, but is not limited thereto. The memory in embodiments of the present invention can also be a circuit or any other device capable of implementing a storage function for storing program instructions and / or data.

[0093] In this embodiment of the invention, the processor may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components, capable of implementing or executing the methods, steps, and logic block diagrams disclosed in this embodiment of the invention. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in this embodiment of the invention can be directly manifested as being executed by a hardware processor, or executed by a combination of hardware and software modules within the processor.

[0094] Based on the same inventive concept as any of the foregoing embodiments, this embodiment of the invention also provides a non-transitory computer-readable storage medium storing computer instructions that cause the computer to execute the described method for quantitative analysis of the stability domain of a doubly-fed variable-speed pumped storage power station regulation system.

[0095] In summary, this invention provides a method for quantitatively analyzing the stability domain of a doubly-fed variable-speed pumped storage power station's regulating system. This method involves establishing a refined model of the regulating system and calculating its stability domain using time-domain simulation. By reducing the order of the refined model, the stability domain and margin domain of the reduced-order model are derived and calculated. Finally, a method is proposed to quantify the stability domain of the refined model using the stability margin of the reduced-order model. This method highlights the stability differences between the refined and reduced-order models of the variable-speed pumped storage power station control system. It can guide personnel in using reduced-order models to tune complex system parameters and optimize hydraulic and electrical parameters, thereby improving the accuracy of the results.

[0096] The terms “comprising” and “having”, and any variations thereof, in the specification, claims, and accompanying drawings of this invention are intended to cover a non-exclusive inclusion, such as a process, method, system, product, or apparatus that includes a series of steps or units, not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. A method for quantitative analysis of the stability domain of a doubly-fed variable-speed pumped storage power station regulation system, characterized in that, include: A refined model of the regulation system of a doubly-fed variable-speed pumped storage power station is established, and the stability region of the refined model is calculated by time-domain simulation. This includes: inputting the internal parameters of the refined model; selecting the two parameters of the governor proportional gain and differential gain inside the refined model as a rectangular coordinate system, and inputting the upper limit of the coordinate axis and the calculation accuracy; initializing the coordinate axis parameters, the number of replacements, and the number of calculations; inputting the actual parameters of the doubly-fed variable-speed pumped storage power station into the refined model for time-domain simulation calculation; plotting all the points that have not diverged from the simulation calculation on the rectangular coordinate axis, and connecting the outermost points to obtain the stability region of the refined model. The refined model is reduced in order, and the stability region and margin region of the reduced model are calculated. The process of reducing the order of the refined model includes: reducing the pipeline model to a second-order elastic pipeline model, reducing the pump-turbine model to a pump-turbine model with six transfer coefficients, and reducing the electrical side model to a first-order model. The calculation of the stability region and margin region of the reduced-order model includes: deriving the comprehensive transfer function based on the reduced-order model; using the denominator of the comprehensive transfer function as the characteristic equation of the variable-speed pumped storage power station regulation system; when the margin region of the variable-speed pumped storage power station regulation system is m, the margin stability characteristic equation satisfies that the real parts of all characteristic roots are less than -m; calculating the margin stability characteristic equation based on the characteristic equation of the variable-speed pumped storage power station regulation system; and applying the Herwitz criterion to the characteristic equation and margin stability characteristic equation of the variable-speed pumped storage power station regulation system to obtain the stability region and margin region of the reduced-order model. Based on the stability margin of the reduced-order model, the stability domain of the refined model is quantified, including: calculating the margin domain and margin domain area of ​​the reduced-order model with two different stability margins; calculating the stability domain area of ​​the refined model; and based on the stability domain area, margin domain, and margin domain area, quantifying the stability margin of the refined model's stability domain relative to the reduced-order model.

2. The method for quantitative analysis of the stability domain of a doubly-fed variable-speed pumped storage power station regulation system according to claim 1, characterized in that, The stability margin of the refined model relative to the reduced-order model in the stability region is quantified using the following expression: ， In the formula, m1 and m2 represent two different stability margins, and A m1 and A m2 Let A represent the area of ​​the margin domain for two descent-order models with different stable margins. j This represents the area of ​​the stability region in the refined model.

3. A stability domain quantitative analysis system for a doubly-fed variable-speed pumped storage power station regulation system, used to implement the method described in any one of claims 1 to 2, characterized in that, include: The first main module is used to establish a refined model of the regulation system of the doubly fed variable speed pumped storage power station and to perform time-domain simulation calculations of the stability domain of the refined model. The second main module is used to reduce the order of the refined model and calculate the stability region and margin region of the reduced model. The third main module is used to quantize the stability region of the refined model based on the stability margin of the reduced-order model.

4. A quantitative analysis device for the stability domain of a doubly-fed variable-speed pumped storage power station regulation system, characterized in that, The system includes a memory and a processor. The memory stores program instructions that are executed by the processor. The processor invokes the program instructions to execute the stability domain quantification analysis method for the doubly fed variable speed pumped storage power station regulation system as described in any one of claims 1 to 2.

5. A non-transitory computer-readable storage medium, characterized in that, The non-transitory computer-readable storage medium stores computer instructions that cause the computer to execute the stability domain quantification analysis method for the doubly-fed variable-speed pumped storage power station regulation system as described in any one of claims 1 to 2.

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