Frequency division and frequency modulation control method and system for power system containing energy storage unit

Abstract

The invention discloses a frequency division frequency modulation control method and system for a power system containing an energy storage unit, and the method comprises the steps: building an energy storage power station comprehensive inertia control model based on an energy storage power station model; considering the influence of energy storage on frequency modulation continuous stability caused by charging and discharging, and establishing a self-adaptive frequency modulation control model considering the energy storage charge state; establishing a frequency response model of the power system based on a balance equation of a wind-light-water-fire power supply, an energy storage unit and a load in the power system; based on the response characteristics of the energy storage unit, establishing a frequency divider model; and comprehensively establishing a frequency control model considering frequency division frequency modulation of the energy storage power supply and other power supplies to realize frequency modulation control of the power system. The frequency modulation advantages that the energy storage unit is high in power supply response speed and can restrain high-frequency fluctuation are brought into play, the frequency response speed of the system is increased, and the frequency response capacity of the system is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of frequency modulation control of energy storage units, and particularly relates to a frequency division and frequency modulation control method and system for a power system containing energy storage units. Background Art

[0002] With the rapid development of new energy power generation, the proportion of new energy in the power system is continuously increasing. Due to the influence of meteorological conditions on wind and light resources, the randomness and volatility of the output of new energy power generation itself pose great challenges to the frequency control of the system. At the same time, with the development of the power system, the dynamic changes of the power grid are getting faster and faster, and the uncertainties existing in the loads in the system also cause fluctuations in the system frequency.

[0003] Energy storage power stations have the advantages of fast response speed and the ability to suppress rapid high-frequency power fluctuations. In the existing energy storage frequency modulation control strategies, the energy storage power station is used as a frequency modulation power source to participate in frequency modulation together with conventional power sources, and the frequency modulation potential of the energy storage unit cannot be effectively utilized. Therefore, how to give full play to the frequency modulation advantages of the energy storage power station for frequency control is worthy of further in-depth research. Summary of the Invention

[0004] The present invention provides a frequency division and frequency modulation control method and system for a power system containing energy storage units, aiming to solve the problems mentioned in the background art.

[0005] In a first aspect, the present invention provides a frequency division and frequency modulation control method for a power system containing energy storage units, including the following steps: Step S1: Based on the energy storage power station model, establish an integrated inertia control model of the energy storage power station to provide inertia response and primary frequency modulation functions; Step S2: Considering the influence of the frequency modulation continuous stability brought by the charge and discharge of the energy storage, establish an adaptive frequency modulation control model considering the state of charge of the energy storage; Step S3: Based on the balance equations of wind, light, water, and fire power sources, energy storage units, and loads in the power system, establish a frequency response model of the power system; Step S4: Based on the response characteristics of the energy storage unit, establish a frequency divider model, and through the frequency divider model, the energy storage unit undertakes the high-frequency component of the frequency deviation, while other power sources undertake the low-frequency component of the frequency deviation; Step S5: Comprehensively establish a frequency control model considering the frequency division and frequency modulation of the energy storage power source and other power sources to achieve the frequency modulation control of the power system.

[0006] Further, step S1 is specifically the following steps: Step S101: For the frequency modulation problem, model the energy storage power station as a first-order dynamic model, and the formula is expressed as: ; In the formula: is the output power of the energy storage power station; is the power reference value of the energy storage power station received by the controller; is the time constant of the energy storage power station; s is the differential operator; Step S102: To enable the energy storage power station to have the functions of inertial response and primary frequency regulation, an integrated inertial control model of the energy storage power station is established, and the formula is expressed as: ; In the formula: is the droop coefficient of the integrated inertial controller of the energy storage power station; is the differential coefficient of the integrated inertial controller of the energy storage power station; is the high-frequency component of the power system frequency fluctuation.

[0007] Furthermore, Step S2 is specifically the following steps: Step S201: Considering the influence of the discharge depth of the energy storage power station on the frequency regulation output, an adaptive frequency regulation control model considering the state of charge of the energy storage is established, and the coefficients of the integrated inertial controller are adaptively adjusted according to the state of charge of the energy storage; The formula for the droop coefficient of the adaptive integrated inertial controller considering the state of charge of the energy storage is expressed as: ; In the formula: is the initial droop coefficient of the integrated inertial controller of the energy storage; is the state of charge of the energy storage power station; is the average value of the state of charge of the energy storage power station; e is the natural constant, is the power system frequency deviation; Step S203: Considering that the frequency dynamic change process of the power system has different frequency regulation requirements in the frequency deterioration and frequency recovery processes, in order to suppress the frequency deterioration and accelerate the frequency recovery during the frequency response process, different integrated inertial controller differential coefficients are used for frequency regulation during the frequency deterioration and frequency recovery processes; The time during the frequency deterioration process is short, and it is necessary to suppress the frequency change within a short time. Therefore, the influence brought by the change of the state of charge is ignored, and ; During the frequency recovery process, since the recovery speed is slow, the differential coefficient of the adaptive integrated inertial controller considering the state of charge of the energy storage is: ; In the formula: is the initial droop coefficient of the integrated inertial controller of the energy storage; is the maximum value of the state of charge of the energy storage power station; is the minimum value of the state of charge of the energy storage power station.

[0008] Further, step S3 is specifically the following steps: Step S301: Based on the dynamic balance equations of various types of power sources and load powers in the power system, when there is a power imbalance between the power generation side and the load side, according to the swing equation of the power system frequency, establish a power system frequency response model, which is expressed by the formula: ; In the formula: , , , and respectively represent the change values of the active power of the photovoltaic power station, the active power of the thermal power plant, the active power of the wind farm, the active power of the hydropower station, and the load power in the power system; M is the inertia time constant of the power system, and D is the load damping coefficient of the power system.

[0009] Further, step S4 is specifically the following steps: Step S401: In order to give full play to the role of the energy storage power station as a power source, establish a frequency divider model. Divide the power system frequency deviation into low-frequency components and high-frequency components through the frequency division channel, and allocate them to different power sources to enable various types of power sources to exert their frequency regulation potential. The formula of the frequency divider model is expressed as: Low-frequency component channel of the frequency divider model: ; In the formula: is the low-frequency component of the power system frequency fluctuation; is the cut-off frequency of the low-frequency component channel of the frequency divider; High-frequency component channel of the frequency divider model: ; After frequency division by the low-frequency component channel and the high-frequency component channel of the frequency divider, the frequency deviation signal of the power system is not attenuated, and the frequency deviation output by the frequency divider model satisfies: ; Therefore, the frequency divider model does not affect the actual demand for power system frequency regulation; Through the frequency divider model, the energy storage unit undertakes the high-frequency component of the frequency deviation, while other power sources undertake the low-frequency component of the frequency deviation, giving play to the frequency regulation advantages of various types of power sources.

[0010] Further, step S5 is specifically the following steps: Based on the adaptive frequency modulation control model considering the state of charge of energy storage and the power system frequency response model, a closed-loop frequency control link of the energy storage power station is established by connecting the output of the high-frequency component channel of the power system frequency deviation with the adaptive frequency modulation control model considering the state of charge of energy storage, so as to achieve the suppression of high-frequency fluctuations by the power source; a closed-loop control link is established by connecting the output of the low-frequency component channel of the power system frequency deviation with the frequency control model of other power sources for frequency division frequency modulation, which is responsible for low-frequency power fluctuations; finally, the frequency regulation of the power system is realized based on the swing control equation of the power system frequency.

[0011] In a second aspect, the present invention provides a power system frequency division frequency modulation control system including an energy storage unit, comprising: An energy storage power station comprehensive inertia control model construction module, configured to establish an energy storage power station comprehensive inertia control model based on the energy storage power station model to provide inertia response and primary frequency modulation functions; An energy storage power station frequency modulation control model construction module, configured to establish an adaptive frequency modulation control model considering the state of charge of energy storage in consideration of the influence of the frequency modulation continuous stability brought by the charge and discharge of energy storage; A power system frequency response model construction module, configured to establish a power system frequency response model based on the balance equations of wind, light, water, and fire power sources, energy storage units, and loads in the power system; A frequency divider model construction module, configured to establish a frequency divider model based on the response characteristics of the energy storage unit, so that the energy storage unit undertakes the high-frequency components of the frequency deviation, while other power sources undertake the low-frequency components of the frequency deviation; A power system frequency modulation control operation module, configured to comprehensively establish a frequency control model considering frequency division frequency modulation of energy storage power sources and other power sources to achieve frequency modulation control of the power system.

[0012] In a third aspect, there is provided an electronic device, which includes: at least one processor, and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the steps of a power system frequency division frequency modulation control method according to any embodiment of the present invention.

[0013] In a fourth aspect, the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program instructions are executed by a processor, the processor executes the steps of a power system frequency division frequency modulation control method according to any embodiment of the present invention.

[0014] The frequency division and frequency modulation control method and system of the power system with energy storage unit in this application, based on the energy storage power station model, establish an integrated inertia control model of the energy storage power station, consider the influence of the frequency modulation continuous stability brought by the charge and discharge of the energy storage, establish a frequency modulation control model of the energy storage power station considering the influence of the state of charge, enable the energy storage power station to have the ability of inertia response and primary frequency modulation, and adopt the principle of time division and segment to prevent the energy storage from overcharging and over-discharging, resulting in the deterioration of the state of charge, and avoid the influence on the stability of the frequency modulation output. Based on the balance equations of wind-solar-hydro-thermal power sources, energy storage units and loads in the power system, establish a frequency response model of the power system, based on the response characteristics of the energy storage unit, establish a frequency divider model, and through the frequency divider model, the energy storage unit undertakes the high-frequency component of the frequency deviation, while other power sources undertake the low-frequency component of the frequency deviation, realizing the frequency division control of the energy storage unit and other types of power sources, giving play to the advantages of the energy storage unit, and improving the frequency characteristics of the power system. The present invention is beneficial to giving play to the frequency modulation advantages of the energy storage unit power source with fast response speed and the ability to suppress high-frequency fluctuations of the frequency, and is beneficial to improving the frequency response speed of the power system and the frequency response ability of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0016] Figure 1 It is a flowchart of a frequency division and frequency modulation control method of a power system with an energy storage unit provided by an embodiment of the present invention; Figure 2 It is a structural block diagram of a frequency division and frequency modulation control system of a power system with an energy storage unit provided by an embodiment of the present invention; Figure 3 It is a schematic structural diagram of an electronic device provided by an embodiment of the present invention; Figure 4 It is a frequency response framework diagram of a frequency division and frequency modulation control system of a power system with an energy storage unit provided by an embodiment of the present invention; Figure 5 It is a comparison diagram of frequency modulation effects of a frequency division and frequency modulation control of a power system with an energy storage unit provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0018] Please refer to Figure 1 , which shows a flowchart of a frequency division and frequency modulation control method for a power system with an energy storage unit according to the present application.

[0019] As Figure 1 shown, a frequency division and frequency modulation control method for a power system with an energy storage unit specifically includes the following steps: Step S1: Based on the energy storage power station model, establish an integrated inertia control model of the energy storage power station to provide inertia response and primary frequency modulation functions; Step S2: Considering the influence of the frequency modulation continuous stability brought by the charging and discharging of the energy storage, establish an adaptive frequency modulation control model considering the state of charge of the energy storage; Step S3: Based on the balance equations of wind, light, water, and fire power sources, energy storage units, and loads in the power system, establish a frequency response model of the power system; Step S4: Based on the response characteristics of the energy storage unit, establish a frequency divider model, and through the frequency divider model, make the energy storage unit bear the high-frequency component of the frequency deviation, while other power sources bear the low-frequency component of the frequency deviation; Step S5: Comprehensively establish a frequency control model considering the frequency division and frequency modulation of the energy storage power source and other power sources to achieve the frequency modulation control of the power system.

[0020] In some embodiments, step S1 is specifically the following steps: Step S101: For the frequency modulation problem, model the energy storage power station as a first-order dynamic model, and the formula is expressed as: ; In the formula: is the output power of the energy storage power station; is the power reference value of the energy storage power station receiving the controller; is the time constant of the energy storage power station; s is the differential operator; Step S102: In order to enable the energy storage power station to have the functions of inertia response and primary frequency modulation, establish an integrated inertia control model of the energy storage power station, and the formula is expressed as: ; In the formula: is the droop coefficient of the integrated inertia controller of the energy storage power station; is the differential coefficient of the integrated inertia controller for the energy storage power station; is the high-frequency component of the frequency fluctuation of the power system.

[0021] In some embodiments, step S2 is specifically the following steps: Step S201: Considering the influence of the discharge depth of the energy storage power station on the frequency regulation output, establish an adaptive frequency regulation control model considering the state of charge of the energy storage, and adaptively adjust the coefficient of the integrated inertia controller according to the state of charge of the energy storage; The formula for the droop coefficient of the adaptive integrated inertia controller considering the state of charge of the energy storage is expressed as: ; In the formula: is the initial droop coefficient of the energy storage integrated inertia controller; is the state of charge of the energy storage power station; is the average value of the state of charge of the energy storage power station; e is the natural constant, is the frequency deviation of the power system; Step S203: Considering that the frequency dynamic change process of the power system has different frequency regulation requirements in the frequency deterioration and frequency recovery processes, in order to suppress the frequency deterioration and accelerate the frequency recovery during the frequency response process, different differential coefficients of the integrated inertia controller are used for frequency regulation in the frequency deterioration and frequency recovery processes; The time during the frequency deterioration process is short, and it is necessary to suppress the frequency change within a short time. Therefore, the influence brought by the change of the state of charge is ignored, and ; During the frequency recovery process, since the recovery speed is slow, the differential coefficient of the adaptive integrated inertia controller considering the state of charge of the energy storage is: ; In the formula: is the initial droop coefficient of the energy storage integrated inertia controller; is the maximum value of the state of charge of the energy storage power station; is the minimum value of the state of charge of the energy storage power station.

[0022] In some embodiments, step S3 is specifically the following steps: Step S301: Based on the dynamic balance equation of various types of power sources and load powers in the power system, when there is a power imbalance between the power generation side and the load side, establish a power system frequency response model according to the swing equation of the power system frequency, and the formula is expressed as: ; In the formula: , , , and They respectively represent the change values of the active power of the photovoltaic power station, the active power of the thermal power plant, the active power of the wind farm, the active power of the hydropower station, and the load power in the power system; M is the inertia time constant of the power system, and D is the load damping coefficient of the system.

[0023] In some embodiments, step S4 is specifically the following steps: Step S401: In order to give full play to the role of the energy storage power station as a power source, a frequency divider model is established. The frequency deviation of the power system is divided into a low-frequency component and a high-frequency component through a frequency division channel and assigned to different power sources so that each type of power source can exert its frequency regulation potential. The formula of the frequency divider model is expressed as: Low-frequency component channel of the frequency divider model: ; In the formula: is the low-frequency component of the frequency fluctuation of the power system; is the cut-off frequency of the low-frequency component channel of the frequency divider; High-frequency component channel of the frequency divider model: ; After frequency division by the low-frequency component channel and the high-frequency component channel of the frequency divider, the frequency deviation signal of the power system does not decay, and the frequency deviation output by the frequency divider model satisfies: ; Therefore, the frequency divider model does not affect the actual requirements of power system frequency regulation; Through the frequency divider model, the energy storage unit undertakes the high-frequency component of the frequency deviation, while other power sources undertake the low-frequency component of the frequency deviation, giving play to the frequency regulation advantages of each type of power source.

[0024] In some embodiments, step S5 is specifically the following steps: Based on the adaptive frequency regulation control model considering the state of charge of the energy storage and the power system frequency response model, a closed-loop frequency control link of the energy storage power station is established between the output of the high-frequency component channel of the power system frequency deviation and the adaptive frequency regulation control model considering the state of charge of the energy storage to achieve the suppression of high-frequency fluctuations by the power source; a closed-loop control link is established between the output of the low-frequency component channel of the power system frequency deviation and the frequency control model of other power sources for frequency division and frequency regulation to be responsible for the low-frequency power fluctuation; finally, the frequency regulation of the power system is achieved based on the swing control equation of the power system frequency.

[0025] In summary, the method of this application constructs a comprehensive inertia control model for the energy storage power station, establishes a frequency modulation control model for the energy storage power station considering the influence of the state of charge, and adopts the principle of time division and segmentation to avoid the influence of the state of charge on the stability of the frequency modulation output when the energy storage is overcharged or over-discharged. A frequency response model of the system is established. Based on the response characteristics of the energy storage unit, a frequency divider model is established to achieve frequency division control of the energy storage unit and other types of power sources, giving play to the advantages of the energy storage unit and improving the frequency characteristics of the system. The present invention is conducive to giving play to the frequency modulation advantage of the energy storage unit power source in suppressing high-frequency fluctuations of the frequency, and is conducive to improving the frequency response speed of the system and the frequency response performance of the system.

[0026] Please refer to Figure 2 , which shows a structural block diagram of a frequency division and frequency modulation control system for a power system with an energy storage unit according to this application.

[0027] As Figure 2 shown, the frequency division and frequency modulation control system 200 for a power system with an energy storage unit includes a comprehensive inertia control model construction module 210 for the energy storage power station, a frequency modulation control model construction module 220 for the energy storage power station, a frequency response model construction module 230 for the power system, a frequency divider model construction module 240, and a frequency modulation control operation module 250 for the power system.

[0028] The comprehensive inertia control model construction module for the energy storage power station is configured to establish a comprehensive inertia control model for the energy storage power station based on the energy storage power station model, and provide inertia response and primary frequency modulation functions; The frequency modulation control model construction module for the energy storage power station is configured to establish an adaptive frequency modulation control model considering the state of charge of the energy storage, taking into account the influence of the frequency modulation continuous stability brought by the charge and discharge of the energy storage; The frequency response model construction module for the power system is configured to establish a frequency response model for the power system based on the balance equations of the wind, light, water, and fire power sources, energy storage units, and loads in the power system; The frequency divider model construction module is configured to establish a frequency divider model based on the response characteristics of the energy storage unit, and through the frequency divider model, the energy storage unit undertakes the high-frequency component of the frequency deviation, while other power sources undertake the low-frequency component of the frequency deviation; The frequency modulation control operation module for the power system is configured to comprehensively establish a frequency control model considering frequency division and frequency modulation of the energy storage power source and other power sources, and realize the frequency modulation control of the power system.

[0029] Among them, the integrated inertia control model construction module 210 of the energy storage power station is configured to establish an adaptive frequency modulation control model considering the state of charge of the energy storage, taking into account the influence of the frequency modulation continuous stability brought by the charge and discharge of the energy storage; the frequency modulation control model construction module 220 of the energy storage power station is configured to establish an adaptive frequency modulation control model considering the state of charge of the energy storage, taking into account the influence of the frequency modulation continuous stability brought by the charge and discharge of the energy storage; the power system frequency response model construction module 230 is configured to establish a frequency response model of the power system based on the balance equations of the wind, light, water, and fire power sources, energy storage units, and loads in the power system; the frequency divider model construction module 240 is configured to establish a frequency divider model based on the response characteristics of the energy storage unit, and through the frequency divider model, the energy storage unit undertakes the high-frequency component of the frequency deviation, while other power sources undertake the low-frequency component of the frequency deviation; the power system frequency modulation control operation module 250 is configured to comprehensively establish a frequency control model considering the frequency division and frequency modulation of the energy storage power source and other power sources to achieve the frequency modulation control of the power system.

[0030] It should be understood that Figure 2 The modules described in Figure 1 correspond to the respective steps in the method described in Figure 2 Thus, the operations, features, and corresponding technical effects described above for the method also apply to

[0031] In some embodiments, the embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the program instructions are executed by a processor, the processor is caused to execute the power system frequency division and frequency modulation control method with an energy storage unit in any of the above method embodiments; As an implementation manner, the computer-readable storage medium of the present invention stores computer-executable instructions, and the computer-executable instructions are set as: Based on the energy storage power station model, establish an integrated inertia control model of the energy storage power station to provide inertia response and primary frequency modulation functions; Consider the influence of the frequency modulation continuous stability brought by the charge and discharge of the energy storage, and establish an adaptive frequency modulation control model considering the state of charge of the energy storage; Based on the balance equations of the wind, light, water, and fire power sources, energy storage units, and loads in the power system, establish a frequency response model of the power system; Based on the response characteristics of the energy storage unit, establish a frequency divider model, and through the frequency divider model, the energy storage unit undertakes the high-frequency component of the frequency deviation, while other power sources undertake the low-frequency component of the frequency deviation; Comprehensively establish a frequency control model considering the frequency division and frequency modulation of the energy storage power source and other power sources to achieve the frequency modulation control of the power system.

[0032] A computer-readable storage medium may include a storage program area and a storage data area. Among them, the storage program area can store an operating system and application programs required for at least one function; the storage data area can store data created according to the use of a power system frequency division and frequency modulation control system including energy storage units, etc. In addition, the computer-readable storage medium may include high-speed random access memory, and may also include memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state storage devices.

[0033] In some embodiments, the computer-readable storage medium may optionally include a memory remotely set relative to the processor, and these remote memories can be connected to the power system frequency division and frequency modulation control system including energy storage units through a network. Examples of the above network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0034] Figure 3 It is a schematic structural diagram of an electronic device provided by an embodiment of the present invention, as Figure 3 shown, the device includes: a processor 310 and a memory 320. The electronic device may further include: an input device 330 and an output device 340. The processor 310, the memory 320, the input device 330, and the output device 340 can be connected through a bus or other means. Figure 3 Taking connection through the bus as an example. The memory 320 is the above-mentioned computer-readable storage medium. The processor 310 executes various functional applications and data processing of the server by running non-volatile software programs, instructions, and modules stored in the memory 320, that is, implementing the power system frequency division and frequency modulation control method including energy storage units in the above method embodiment. The input device 330 can receive input digital or character information, and generate key signal inputs related to user settings and function controls of a power system frequency division and frequency modulation control system including energy storage units. The output device 340 may include a display device such as a display screen.

[0035] The above electronic device can execute the method provided by the embodiment of the present invention, and has corresponding functional modules and beneficial effects for executing the method. For technical details not described in detail in this embodiment, reference can be made to the method provided by the embodiment of the present invention.

[0036] As an implementation manner, the above electronic device is applied to a power system frequency division and frequency modulation control system including energy storage units and is used for a client, including: at least one processor; and a memory communicatively connected to the at least one processor; wherein, the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the power system frequency division and frequency modulation control method including energy storage units.

[0037] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on such an understanding, the essence of the above technical solution, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods of each embodiment or some parts of the embodiments.

[0038] The present invention is verified and designed in the power system frequency response model as Figure 4 shown. As Figure 5 shown in the comparison diagram of the frequency modulation effect of an embodiment of the present invention, it can be seen from Figure 5 this that compared with the traditional frequency control method, the power system frequency division frequency modulation control method with an energy storage unit proposed by the present invention has smaller power system frequency fluctuations and better power system frequency response performance.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A frequency splitting and frequency modulation control method for a power system with an energy storage unit, characterized in that It includes the following steps: Step S1: Based on the energy storage power station model, establish an integrated inertia control model for the energy storage power station to provide inertia response and primary frequency regulation functions; Step S2: Considering the impact of charge and discharge of energy storage on the continuous stability of frequency regulation, establish an adaptive frequency regulation control model considering the state of charge of energy storage; Step S3: Based on the balance equations of wind, light, water, and thermal power sources, energy storage units, and loads in the power system, establish a frequency response model of the power system; Step S4: Based on the response characteristics of the energy storage unit, establish a frequency divider model. Through the frequency divider model, the energy storage unit undertakes the high-frequency component of the frequency deviation, while other power sources undertake the low-frequency component of the frequency deviation; Step S5: Comprehensively establish a frequency control model considering the frequency division and frequency regulation of energy storage power sources and other power sources to achieve the frequency regulation control of the power system.

2. The frequency division and frequency modulation control method for a power system with an energy storage unit according to claim 1, wherein Step S1 is specifically the following steps: Step S101: For the frequency regulation problem, model the energy storage power station as a first-order model, and the formula is expressed as: ； Wherein: is the output power of the energy storage power station; is the power reference value of the energy storage power station received by the controller; is the time constant of the energy storage power station; s is the differential operator; Step S102: In order to enable the energy storage power station to have the functions of inertia response and primary frequency regulation, establish an integrated inertia control model for the energy storage power station, and the formula is expressed as: ； Wherein: is the droop coefficient of the integrated inertia controller of the energy storage power station; is the differential coefficient of the integrated inertia controller of the energy storage power station; is the high-frequency component of the frequency fluctuation of the power system.

3. A frequency-divided frequency modulation control method for a power system with an energy storage unit according to claim 2, characterized in that, Step S2 is specifically the following steps: Step S201: Considering the impact of the discharge depth of the energy storage power station on the frequency regulation output, establish an adaptive frequency regulation control model considering the state of charge of energy storage, and adaptively adjust the coefficient of the integrated inertia controller according to the state of charge of energy storage; The formula for the droop coefficient of the adaptive integrated inertia controller considering the state of charge of energy storage is expressed as: ； In the formula: is the initial droop coefficient of the energy storage integrated inertia controller; is the state of charge of the energy storage power station; is the average value of the state of charge of the energy storage power station; e is the natural constant, is the frequency deviation of the power system; Step S203: Considering that the frequency dynamic change process of the power system has different frequency regulation requirements in the frequency deterioration and frequency recovery processes, use different differential coefficients of the integrated inertia controller for frequency regulation in the frequency deterioration and frequency recovery processes; During the frequency deterioration process, the influence brought about by the change in the state of charge is ignored, and ; In the frequency recovery process, the differential coefficient of the adaptive integrated inertia controller considering the state of charge of energy storage is: ； Wherein: is the initial droop coefficient of the energy storage comprehensive inertia controller; is the maximum value of the state of charge of the energy storage power station; is the minimum value of the state of charge of the energy storage power station.

4. A frequency division and frequency modulation control method for a power system with an energy storage unit according to claim 3, characterized in that, Step S3 is specifically the following steps: Step S301: Based on the dynamic balance equations of various types of power sources and load powers in the power system, when there is a power imbalance between the power generation side and the load side, establish a frequency response model of the power system according to the swing equation of the power system frequency, and the formula is expressed as: ； Where: , , , and respectively represent the change values of the active power of the photovoltaic power station, the active power of the thermal power plant, the active power of the wind farm, the active power of the hydropower station, and the load power in the power system; M is the inertia time constant of the power system, and D is the load damping coefficient of the power system.

5. A frequency-divided frequency modulation control method for a power system with an energy storage unit according to claim 4, characterized in that, Step S4 is specifically the following steps: Step S401: In order to give full play to the role of the energy storage power station, establish a frequency divider model. Through the frequency division channel, divide the power system frequency deviation into low-frequency and high-frequency components, and allocate them to different power sources to enable each type of power source to exert its frequency regulation potential. The formula of the frequency divider model is expressed as: Low-frequency component channel of the frequency divider model: ； Wherein: is the low-frequency component of the frequency fluctuation of the power system; is the cut-off frequency of the low-frequency component channel of the frequency divider; High-frequency component channel of the frequency divider model: ； The output frequency deviation of the frequency divider model satisfies: ； Through the frequency divider model, the energy storage unit undertakes the high-frequency component of the frequency deviation, while other power sources undertake the low-frequency component of the frequency deviation.

6. A frequency division and frequency modulation control method for a power system with an energy storage unit according to claim 5, characterized in that, Step S5 is specifically the following steps: Based on the adaptive frequency modulation control model considering the state of charge of energy storage and the power system frequency response model, a closed-loop frequency control link of the energy storage power station is established by combining the output of the high-frequency component channel of the power system frequency deviation with the adaptive frequency modulation control model considering the state of charge of energy storage, so as to achieve the suppression of high-frequency fluctuations by the power source; a closed-loop control link is established by combining the output of the low-frequency component channel of the power system frequency deviation with the frequency control model of other power sources for frequency division frequency modulation to be responsible for the low-frequency power fluctuations; finally, the frequency regulation of the power system is realized based on the swing control equation of the power system frequency.

7. A power system frequency splitting and frequency modulation control system including an energy storage unit, characterized in that Including: An energy storage power station comprehensive inertia control model construction module, configured to establish an energy storage power station comprehensive inertia control model based on the energy storage power station model to provide inertia response and primary frequency modulation functions; An energy storage power station frequency modulation control model construction module, configured to establish an adaptive frequency modulation control model considering the state of charge of energy storage in consideration of the influence of the frequency modulation continuous stability brought by the charge and discharge of energy storage; A power system frequency response model construction module, configured to establish a power system frequency response model based on the balance equations of wind, light, water, and fire power sources, energy storage units and loads in the power system; A frequency divider model construction module, configured to establish a frequency divider model based on the response characteristics of the energy storage unit, so that the energy storage unit undertakes the high-frequency components of the frequency deviation, while other power sources undertake the low-frequency components of the frequency deviation; A power system frequency modulation control operation module, configured to comprehensively establish a frequency control model considering the frequency division frequency modulation of energy storage power sources and other power sources to achieve the frequency modulation control of the power system.

8. An electronic device, characterized in that, Including: At least one processor, and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, The computer program realizes the method according to any one of claims 1 to 6 when executed by the processor.

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