Unit frequency modulation method based on multi-type power supply SFR model and related device

Abstract

The invention discloses a unit frequency modulation method based on a multi-type power supply SFR model and a related device, and belongs to the technical field of power system frequency modulation. The method comprises the following steps: constructing a system frequency response model, and obtaining a matching relation between system inertia and primary frequency modulation speed through simulation analysis; frequency modulation characteristic parameters of a system unit are obtained, and a multi-type power supply SFR model is constructed based on the matching relation between the system inertia and the primary frequency modulation speed; and when the power system is disturbed, inertia response and primary frequency modulation action are coordinated through a multi-type power supply SFR model, so that the system frequency is dynamically recovered to a stable range. Through multi-type power supply cooperative frequency modulation and dynamic staged control, rapid, accurate and safe recovery of the frequency of the power system is realized, and the method is especially suitable for the frequency modulation demand of a high-proportion new energy power system, and has significant economic and social benefits.

Description

Technical Field

[0001] The present invention belongs to the technical field of power system frequency regulation, and relates to a unit frequency regulation method based on a multi-type power supply SFR model and related devices. Background Art

[0002] Amidst the accelerating transformation of the global energy mix, the traditional electricity supply model, which primarily relies on fossil fuels, is gradually evolving towards a more diversified and cleaner approach. Renewable energy sources such as solar, wind, hydro, and biomass, owing to their clean and sustainable characteristics, are playing an increasingly important role in the power system. At the same time, new power elements such as energy storage technologies and distributed power sources are increasingly being integrated into the power grid. The interconnection of multiple power sources has provided the power system with a richer energy supply, effectively improving energy efficiency, reducing reliance on traditional fossil fuels, and achieving energy conservation and emission reduction goals.

[0003] However, the integration of multiple power sources also presents new challenges to the stable operation of the power system, with frequency regulation being a particularly prominent issue. Different types of power sources have unique dynamic characteristics. Take wind power generation, for example. The randomness and intermittence of wind speed make the output power of wind turbines extremely unstable, making it difficult to accurately predict and control. Sudden changes in wind speed can cause significant fluctuations in wind turbine output power, requiring the power system to respond quickly and adjust the output of other power sources to maintain system frequency stability. Solar photovoltaic power generation faces similar challenges. Fluctuations in light intensity can lead to unstable output power from photovoltaic power stations. Furthermore, photovoltaic power generation is significantly affected by weather conditions, with output power significantly declining on cloudy, rainy days, or at night. In contrast, traditional synchronous generators have good frequency regulation capabilities, but their large rotor inertia results in relatively slow response speeds. Newer distributed power sources, such as fuel cells and micro-turbines, also have varying frequency regulation characteristics and response capabilities.

[0004] In existing technologies, power systems with multiple power sources suffer from slow frequency regulation response and low frequency regulation accuracy. Due to the difficulty in coordinating and controlling multiple power sources, when the system frequency deviates, there is a significant delay in the response between the power sources. The varying control strategies and response times of different power sources prevent the frequency regulation of the entire power system from being carried out in a timely and uniform manner. This can cause the system frequency to remain in a deviated state for extended periods, increasing the risk of system instability. Summary of the Invention

[0005] The purpose of the present invention is to provide a unit frequency regulation method and related devices based on the SFR model of multiple types of power sources, so as to solve the technical problems of slow frequency regulation response speed and low frequency regulation accuracy of power systems with multiple types of power sources in the prior art.

[0006] To achieve the above object, the application adopts the following technical solutions to achieve the above object: In a first aspect, the application provides a unit frequency modulation method based on a multi-type power source SFR model, comprising the following steps: A system frequency response model is constructed, and a matching relationship between system inertia and primary frequency modulation speed is obtained through simulation analysis; The frequency modulation characteristic parameters of the system unit are obtained, and a multi-type power source SFR model is constructed based on the matching relationship between system inertia and primary frequency modulation speed; When a disturbance occurs in the power system, the inertia response and the primary frequency modulation action are coordinated through the multi-type power source SFR model, so that the system frequency dynamic is restored to the stable range.

[0007] Further, the step of constructing the system frequency response model and obtaining the matching relationship between the system inertia and the primary frequency modulation speed through simulation analysis specifically comprises: An equivalent generator rotor motion equation is used to describe the system frequency dynamic, and the specific formula is:

[0008] In the formula, is the inertia center frequency change amount; is the equivalent generator mechanical power change amount; is the disturbance power; is the load frequency regulation coefficient; is the system inertia constant; Through step disturbance simulation, the frequency minimum point under different system inertia levels and primary frequency modulation speed combinations is analyzed to determine the matching relationship that meets the frequency safety constraint condition.

[0009] Further, the frequency safety constraint condition is that the frequency minimum point is not less than 49.2 Hz.

[0010] Further, the system unit includes a hydroelectric unit, a thermal power unit, and a new energy unit.

[0011] Further, the step of when a disturbance occurs in the power system, coordinating the inertia response and the primary frequency modulation action through the multi-type power source SFR model, and restoring the system frequency dynamic to the stable range specifically comprises: When the power system is subjected to a power shortage disturbance of load step increase, the disturbance power is immediately shared by synchronous machines and virtual synchronous machines, and the electromagnetic power suddenly increases to balance the disturbance power; The inertia response is triggered, the inertia support power is provided by the system generalized inertia, the active power supply-demand balance of the system is maintained, and the frequency change speed is slowed down; After the conversion speed slows down, the speed regulator is triggered to act. Through the coordinated action of inertia response and primary frequency modulation, power is supplied to the system until the mechanical power and electromagnetic power are balanced and the system frequency reaches the lowest point, entering the frequency recovery stage. During the frequency recovery phase, the prime mover generates additional mechanical power to bring the rotor speed back to the rated value.

[0012] Furthermore, the system generalized inertia includes the inertia provided by thermal power units, hydropower units and new energy units, and the system generalized kinetic energy is expressed as:

[0013] Where, Energy provided to thermal power units; Energy provided to hydroelectric units; is the energy form provided by the new energy; then the generalized inertia constant of the system is:

[0014] Where, Total rated generating capacity for the system; is the system inertia constant, including conventional power supply and new energy units; is the generalized kinetic energy of the system.

[0015] Furthermore, it also includes: Based on the SFR model of multiple power sources, the critical inertia requirements of the system under different renewable energy penetration rates are calculated to determine the maximum penetration rate that does not trigger underfrequency load shedding. Optimize power system configuration based on the maximum penetration rate without triggering underfrequency load shedding.

[0016] In a second aspect, the present invention provides a unit frequency regulation system based on a multi-type power supply SFR model, comprising: The matching module is used to build a system frequency response model and obtain the matching relationship between the system inertia and the primary frequency modulation speed through simulation analysis; The model building module is used to obtain the frequency regulation characteristic parameters of the system units and build SFR models of multiple types of power supplies based on the matching relationship between system inertia and primary frequency regulation speed; The frequency regulation module is used to coordinate the inertia response and the primary frequency regulation action through the multi-type power supply SFR model when the power system is disturbed, so that the system frequency can be dynamically restored to a stable range.

[0017] In a third aspect, the present invention provides a computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0018] In a fourth aspect, the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0019] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a unit frequency regulation method and related device based on a multi-type power source SFR model. By constructing a system frequency response (SFR) model and simulating and analyzing the matching relationship between inertia and primary frequency regulation speed, it can accurately quantify the frequency regulation requirements of different power sources, avoiding the response lag or overregulation problems caused by parameter mismatch in traditional frequency regulation methods. By integrating the differentiated frequency regulation characteristics of thermal power, hydropower, and renewable energy units (such as the steady-state frequency regulation capability of thermal power, the rapid response of hydropower, and the grid construction / follow-up control strategies of renewable energy), a multi-type power source SFR model is constructed to achieve global optimal allocation of frequency regulation resources. In the initial stage of a disturbance, the rapid power support capabilities of synchronous generators, virtual synchronous generators, and generalized inertia are utilized to effectively suppress sharp frequency drops, creating a critical time window for subsequent primary frequency regulation. During the speed regulator operation phase, the inertia response and primary frequency regulation work together to quickly offset power shortages while avoiding the excessive frequency fluctuations caused by a single frequency regulation method. During the frequency recovery phase, the frequency is steadily restored to near the rated value through increased power generation from the prime movers and dynamic regulation of the renewable energy units, reducing the risk of frequency oscillation. This invention achieves rapid, accurate, and safe restoration of the power system frequency through coordinated frequency modulation of multiple power sources and dynamic, phased control. It is particularly well-suited for the frequency modulation needs of power systems with a high proportion of renewable energy, and offers significant economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 is a flow chart of the method of the present invention; Figure 2 is a schematic diagram of the system of the present invention; Figure 3 This is a schematic diagram of the dynamic frequency results in the matching phase according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the SFR model of multiple types of power supplies according to an embodiment of the present invention; Figure 5 It is a schematic diagram of the computer device structure of the present invention. DETAILED DESCRIPTION

[0022] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that, unless there is a conflict, the embodiments and features in the embodiments of the present application can be combined with each other.

[0023] The following detailed description is an exemplary description, which is intended to provide further detailed description of the present invention. Unless otherwise indicated, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art. The terms used in the present invention are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention.

[0024] See also Figure 1 The embodiment of the present invention discloses a method for frequency regulation of a generator set based on a multi-type power supply SFR model, comprising the following steps: S1, build the system frequency response model and obtain the matching relationship between system inertia and primary frequency modulation speed through simulation analysis; The equivalent generator rotor motion equation is used to describe the system frequency dynamics. The specific formula is:

[0025] Where, is the change in the center frequency of inertia; is the change in the equivalent generator mechanical power; is the disturbance power; is the load frequency regulation coefficient; is the system inertia constant; Through step disturbance simulation, the lowest frequency point under different system inertia levels and primary frequency modulation speed combinations was analyzed to determine the matching relationship that meets the frequency safety constraint condition. The frequency safety constraint condition is that the lowest frequency point is no less than 49.2Hz.

[0026] The minimum point of system frequency after active power disturbance is affected by inertia and primary frequency modulation capability, and determines whether the system low frequency load shedding action will be triggered. For the active power shortage caused by fault, if the shortage is greater than the primary frequency modulation margin reserved in the system, the low frequency load shedding must be relied on to prevent the frequency from falling further to trigger a chain accident. If the shortage is less than the primary frequency modulation margin reserved in the system, but because of the slow primary frequency modulation speed and limited inertia, the frequency drops to the level of triggering low frequency load shedding, which indicates that there is a problem in the design of the inertia and primary frequency modulation margin and speed in the system. Therefore, in order to ensure that the system does not trigger low frequency load shedding after disturbance, it is necessary to analyze the comprehensive demand of inertia and primary frequency modulation in the system. The range of N-1 generated power shortage level in each regional power grid is generally 3%~9%, and the power shortage in the SFR model is set to 6% under the constraint condition of not triggering low frequency load shedding (the minimum point of frequency is not less than 49.2Hz), and the primary frequency modulation margin of power supply in the SFR model is also set to 6%, which covers the power shortage. This is the most stringent working condition for testing the matching relationship between the inertia level and the primary frequency modulation speed of the system. Figure 3 The minimum inertia level required by the system to meet the condition that the frequency is not less than 49.2Hz under different primary frequency modulation speeds is given as follows: , )。

[0027] From Figure 3 , the frequency drops to 49.2Hz and the value no longer changes, because the primary frequency modulation margin reserved in the system is equal to the power shortage, and the active power generated by the original motor after the frequency reaches the minimum point just offsets the power shortage. According to the equivalent generator rotor motion equation, the frequency change rate is zero. Table 1 gives the corresponding relationship between the primary frequency modulation time constant (the time constant of the first order delay link of primary frequency modulation) and the inertia constant at the minimum point of frequency 49.2Hz.

[0028] Table 1 Matching relationship between inertia and primary frequency modulation speed

[0029] From Table 1, under the same constraint of minimum frequency, the smaller the primary frequency modulation time constant of the system, the smaller the inertia constant required by the system, and the two are in a proportional relationship. According to Table 1, if the primary frequency modulation function of new energy can be abstracted as a first order delay link, and the time constant is about 1s, then the new energy should provide an inertia of 2.08s inertia constant.

[0030] S2, obtain the frequency modulation characteristic parameters of the system unit, based on the matching relationship between system inertia and primary frequency modulation speed, construct a multi-type power supply SFR model; The actual running system contains multiple types of power sources with different frequency response characteristics. In this embodiment, the inertia and primary frequency regulation performance of three types of power sources, including thermal power, hydroelectric power and new energy units, are sorted out, as shown in Table 2.

[0031] Table 2 Frequency response performance of multiple types of power sources

[0032] If the new energy does not have frequency regulation function and inertia support capability, the inertia level of the system will decrease after the synchronous unit is replaced by the new energy unit. To avoid triggering low-frequency load shedding after the system is disturbed, the maximum penetration rate of new energy under this scenario is explored. The establishment of the SFR model of multiple types of power sources is based on the classical SFR model considering only the primary frequency regulation of thermal power. The frequency characteristics of the system under different penetration rates are analyzed, and the transfer function block diagram is as follows Figure 4 .

[0033] S3, when the power system is disturbed, the inertia response and primary frequency regulation action are coordinated through the SFR model of multiple types of power sources, so that the system frequency dynamic returns to the stable range.

[0034] When the power system is disturbed by the power shortage of load step increase, the synchronous machine and virtual synchronous machine immediately share the disturbance power, and the electromagnetic power suddenly increases to balance the disturbance power; Triggering inertia response, inertia support power is provided by the system generalized inertia to maintain the balance of active power supply and demand of the system and slow down the frequency change speed. The system generalized inertia includes the inertia provided by thermal power units, hydroelectric power units and new energy units, and the system generalized kinetic energy is represented as:

[0035] In the formula, is the energy provided by the thermal power unit; is the energy provided by the hydroelectric power unit; is the energy provided by the new energy; and the system generalized inertia constant is:

[0036] In the formula, is the total rated generating capacity of the system; is the system inertia constant, including conventional power sources and new energy units; is the system generalized kinetic energy.

[0037] After the transformation speed slows down, the governor action is triggered, the inertia response and primary frequency regulation are coordinated to provide power to the system until the mechanical power and electromagnetic power are balanced, the system frequency reaches the lowest point, and enters the frequency recovery stage; During the frequency recovery phase, the prime mover generates additional mechanical power to bring the rotor speed back to the rated value.

[0038] Preferably, based on the multi-type power source SFR model, the critical inertia demand of the system under different new energy penetration rates can be calculated to determine the maximum penetration rate that does not trigger low-frequency load reduction; based on the maximum penetration rate that does not trigger low-frequency load reduction, the power system configuration is optimized.

[0039] See also Figure 2 The embodiment of the present invention discloses a unit frequency regulation system based on a multi-type power supply SFR model, including a matching module, a model building module and a frequency regulation module.

[0040] Among them, the matching module is used to build a system frequency response model and obtain the matching relationship between the system inertia and the primary frequency modulation speed through simulation analysis; the model construction module is used to obtain the frequency modulation characteristic parameters of the system units and build a multi-type power supply SFR model based on the matching relationship between the system inertia and the primary frequency modulation speed; the frequency modulation module is used to coordinate the inertia response and the primary frequency modulation action through the multi-type power supply SFR model when a disturbance occurs in the power system, so that the system frequency dynamically recovers to a stable range.

[0041] In one embodiment of the present invention, see Figure 5 , provides a computer device, which includes a processor and a memory, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, and is suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function; the processor described in the embodiment of the present invention can be used for the operation of a unit frequency regulation method based on a multi-type power supply SFR model.

[0042] The application further provides a storage medium, specifically a computer readable storage medium (Memory), which is a memory device in a computer device and is used for storing programs and data. It can be understood that the computer readable storage medium herein can include a built-in storage medium in the computer device, and of course can include an extended storage medium supported by the computer device. The computer readable storage medium provides a storage space, which stores an operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and the instructions can be one or more computer programs (including program codes). It should be noted that the computer readable storage medium herein can be a high-speed RAM memory or a non-volatile memory, for example, at least one disk memory. One or more instructions stored in the computer readable storage medium can be loaded and executed by the processor to implement the corresponding steps of the unit frequency regulation method based on the multi-type power SFR model in the above embodiments.

[0043] Those skilled in the art will appreciate that embodiments of the application can be supplied as a method, a system, or a computer program product. Therefore, the application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage media, etc.) containing computer-usable program code.

[0044] The application is described with reference to flowcharts and / or block diagrams of the method, device (system), and computer program product according to embodiments of the application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of flows and / or blocks in the flowcharts 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, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device that implements the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 an apparatus that performs the functions specified in one or more flows or blocks.

[0045] These computer program instructions can also be stored in a computer readable memory that can direct the computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce a manufactured product including instruction apparatus, which implements the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1The function specified in one or more boxes.

[0046] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0047] 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 it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A unit frequency regulation method based on a multi-type power supply SFR model, characterized in that: The following steps are involved: Build a system frequency response model and obtain the matching relationship between system inertia and primary frequency modulation speed through simulation analysis; Obtain the frequency regulation characteristic parameters of the system units and build a multi-type power supply SFR model based on the matching relationship between system inertia and primary frequency regulation speed; When a disturbance occurs in the power system, the inertia response and the primary frequency regulation action are coordinated through the multi-type power supply SFR model to dynamically restore the system frequency to a stable range.

2. The method for frequency regulation of a generator set based on a multi-type power supply SFR model according to claim 1, characterized in that: The step of constructing a system frequency response model and obtaining the matching relationship between the system inertia and the primary frequency modulation speed through simulation analysis specifically includes: The equivalent generator rotor motion equation is used to describe the system frequency dynamics. The specific formula is: Where, is the change in the center frequency of inertia; is the change in the equivalent generator mechanical power; is the disturbance power; is the load frequency regulation coefficient; is the system inertia constant; Through step disturbance simulation, the lowest frequency point under different system inertia levels and primary frequency modulation speed combinations is analyzed to determine the matching relationship that meets the frequency safety constraint conditions.

3. The method for frequency regulation of a generator set based on a multi-type power supply SFR model according to claim 2, characterized in that: The frequency safety constraint condition is: the lowest frequency point is not less than 49.2 Hz.

4. The method for frequency regulation of a generator set based on a multi-type power supply SFR model according to claim 1, characterized in that: The system units include hydropower units, thermal power units and new energy units.

5. The method for frequency regulation of a generator set based on a multi-type power supply SFR model according to claim 1, characterized in that: The steps of dynamically restoring the system frequency to a stable range by coordinating the inertia response and the primary frequency regulation action through the multi-type power supply SFR model when a disturbance occurs in the power system specifically include: When the power system is disturbed by a power shortage caused by a step increase in load, the disturbance power is immediately shared by the synchronous machine and the virtual synchronous machine, and the electromagnetic power surges to balance the disturbance power. Triggering inertia response, the system's generalized inertia provides inertia support power, maintaining the system's active power supply and demand balance and slowing down the frequency change rate; After the conversion speed slows down, the speed regulator is triggered to act. Through the coordinated action of inertia response and primary frequency modulation, power is supplied to the system until the mechanical power and electromagnetic power are balanced and the system frequency reaches the lowest point, entering the frequency recovery stage. During the frequency recovery phase, the prime mover generates additional mechanical power to bring the rotor speed back to the rated value.

6. The method for frequency regulation of a generator set based on a multi-type power supply SFR model according to claim 5, characterized in that: The generalized inertia of the system includes the inertia provided by thermal power units, hydropower units and new energy units. The generalized kinetic energy of the system is expressed as: Where, Energy provided to thermal power units; Energy provided to hydroelectric units; is the energy form provided by the new energy; then the generalized inertia constant of the system is: Where, Total rated generating capacity for the system; is the system inertia constant, including conventional power supply and new energy units; is the generalized kinetic energy of the system.

7. The method for frequency regulation of a generator set based on a multi-type power supply SFR model according to claim 1, characterized in that: Also includes: Based on the SFR model of multiple power sources, the critical inertia requirements of the system under different renewable energy penetration rates are calculated to determine the maximum penetration rate that does not trigger underfrequency load shedding. Optimize power system configuration based on the maximum penetration rate without triggering underfrequency load shedding.

8. A unit frequency regulation system based on a multi-type power supply SFR model, characterized in that: include: The matching module is used to build a system frequency response model and obtain the matching relationship between the system inertia and the primary frequency modulation speed through simulation analysis; The model building module is used to obtain the frequency regulation characteristic parameters of the system units and build SFR models of multiple types of power supplies based on the matching relationship between system inertia and primary frequency regulation speed; The frequency regulation module is used to coordinate the inertia response and the primary frequency regulation action through the multi-type power supply SFR model when the power system is disturbed, so that the system frequency can be dynamically restored to a stable range.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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