A frequency division frequency modulation control method and system for a power system containing energy storage units

Abstract

The application discloses a kind of power system frequency division frequency control method and system containing energy storage unit, method includes: based on energy storage power station model, establish energy storage power station comprehensive inertia control model;Considering the influence of frequency modulation stability of energy storage due to charging and discharging, an adaptive frequency modulation control model considering the state of charge of energy storage is established;Based on the balance equation of wind, light, water and fire power, energy storage unit and load in power system, the frequency response model of power system is established;Based on the response characteristics of energy storage unit, a frequency divider model is established;Comprehensive frequency control model considering frequency division frequency of energy storage power and other power is established, the frequency modulation control of power system is realized.The application is conducive to the frequency modulation advantage of fast response speed of energy storage unit power, can suppress frequency high-frequency fluctuation, is conducive to improving system frequency response speed, improving the frequency response capability of system.

Description

Technical Field

[0001] The present invention belongs to the technical field of frequency modulation control of energy storage units, and in particular 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 renewable energy generation, the proportion of renewable energy in the power system continues to increase. Because wind and solar resources are affected by meteorological conditions, the inherent randomness and volatility of renewable energy generation pose significant challenges to system frequency control. Furthermore, with the development of the power system, the dynamics of the grid are changing at an increasingly rapid pace, and the uncertainty of loads within the system also causes fluctuations in system frequency.

[0003] Energy storage power stations offer the advantages of fast response and the ability to suppress rapid, high-frequency power fluctuations. However, existing energy storage frequency regulation control strategies utilize energy storage power stations as frequency-regulating power sources alongside conventional power sources, failing to effectively utilize the frequency regulation potential of energy storage units. Therefore, further research is needed to fully leverage the frequency regulation advantages of energy storage power stations for frequency control. Summary of the Invention

[0004] The present invention provides a frequency division and frequency modulation control method and system for an electric power system including an energy storage unit, which aims to solve the problems mentioned in the background technology.

[0005] In a first aspect, the present invention provides a method for controlling frequency division and frequency modulation of a power system including an energy storage unit, comprising the following steps:

[0006] Step S1: Based on the energy storage power station model, a comprehensive inertial control model of the energy storage power station is established to provide inertial response and primary frequency regulation functions;

[0007] Step S2: Considering the impact of energy storage on the frequency modulation stability caused by charging and discharging, an adaptive frequency modulation control model considering the energy storage charge state is established;

[0008] Step S3: Establishing a frequency response model of the power system based on the balance equations of wind, solar, hydro, and thermal power sources, energy storage units, and loads in the power system;

[0009] Step S4: Based on the response characteristics of the energy storage unit, a frequency divider model is established, and the frequency divider model is used to 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;

[0010] Step S5: A frequency control model is comprehensively established that takes into account the frequency division and frequency modulation of the energy storage power source and other power sources to realize the frequency modulation control of the power system.

[0011] Furthermore, step S1 is specifically the following steps:

[0012] Step S101: For the frequency regulation problem, the energy storage power station is modeled as a first-order dynamic model, which is expressed as follows:

[0013] ;

[0014] Where: is the output power of the energy storage power station; Receive power reference value from controller for energy storage power station; is the time constant of the energy storage power station; s is the differential operator;

[0015] Step S102: In order to enable the energy storage power station to have the functions of inertial response and primary frequency regulation, a comprehensive inertial control model of the energy storage power station is established. The formula is expressed as follows:

[0016] ;

[0017] Where: 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; It is the high-frequency component of the power system frequency fluctuation.

[0018] Furthermore, step S2 is specifically the following steps:

[0019] Step S201: Considering the impact of the discharge depth of the energy storage power station on the frequency modulation output, an adaptive frequency modulation control model considering the energy storage charge state is established, and the comprehensive inertia controller coefficient is adaptively adjusted according to the energy storage charge state;

[0020] Step S202: The formula for the droop coefficient of the adaptive integrated inertia controller considering the energy storage charge state is expressed as:

[0021] ;

[0022] Where: is the initial droop coefficient of the energy storage integrated inertia controller; The charging state of the energy storage power station; is the average state of charge of the energy storage power station; e is a natural constant, is the power system frequency deviation;

[0023] Step S203: Considering the different frequency regulation requirements during the frequency deterioration and frequency recovery processes of the power system frequency dynamic change process, in order to suppress frequency deterioration and accelerate frequency recovery during the frequency response process, different integrated inertia controller differential coefficients are used to perform frequency regulation during the frequency deterioration and frequency recovery processes;

[0024] The frequency deterioration process is short, and the frequency change needs to be suppressed in a short time, so the impact of the charge state change is ignored, and ;

[0025] During the frequency recovery process, since the recovery speed is slow, the differential coefficient of the adaptive integrated inertia controller considering the energy storage charge state is:

[0026] ;

[0027] Where: is the initial droop coefficient of the energy storage integrated inertia controller; The maximum state of charge of the energy storage power station; It is the minimum state of charge of the energy storage station.

[0028] Furthermore, step S3 is specifically the following steps:

[0029] Step S301: Based on the dynamic balance equations of power of various types of power sources and loads in the power system, when power imbalance occurs between the generation side and the load side, a power system frequency response model is established according to the swing equation of the power system frequency. The formula is expressed as follows:

[0030] ;

[0031] Where: 、 、 、 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 power system.

[0032] Furthermore, step S4 is specifically the following steps:

[0033] Step S401: To fully utilize the power source of the energy storage station, a frequency divider model is established. The frequency deviation of the power system is divided into low-frequency components and high-frequency components through the frequency division channel. The components are then allocated to different power sources to enable each type of power source to realize its frequency regulation potential. The formula of the frequency divider model is expressed as follows:

[0034] Crossover model low frequency component channel:

[0035] ;

[0036] Where: It is the low-frequency component of the power system frequency fluctuation; is the cutoff frequency of the low-frequency component channel of the crossover;

[0037] Crossover model high frequency component channel:

[0038] ;

[0039] After the frequency deviation signal of the power system is divided by the low-frequency component channel and the high-frequency component channel of the divider, it is not attenuated. The frequency deviation output by the divider model satisfies:

[0040] ;

[0041] Therefore, the divider model does not affect the actual demand for power system frequency regulation;

[0042] Through the divider model, the energy storage unit bears the high-frequency component of the frequency deviation, while other power sources bear the low-frequency component of the frequency deviation, giving full play to the frequency regulation advantages of various types of power sources.

[0043] Furthermore, step S5 is specifically the following steps:

[0044] Based on the adaptive frequency modulation control model considering the energy storage charge state and the power system frequency response model, the output of the high-frequency component channel of the power system frequency deviation is combined with the adaptive frequency modulation control model considering the energy storage charge state to establish a closed-loop frequency control link of the energy storage power station, so as to realize the power supply's suppression of high-frequency fluctuations; the output of the low-frequency component channel of the power system frequency deviation is combined with the frequency control model of other power supply frequency division modulation to establish a closed-loop control link, which is responsible for low-frequency power fluctuations; finally, the frequency regulation of the power system is realized based on the power system frequency swing control equation.

[0045] In a second aspect, the present invention provides a power system frequency division and frequency modulation control system including an energy storage unit, comprising:

[0046] The energy storage power station integrated inertia control model construction module is configured to establish an integrated inertia control model of the energy storage power station based on the energy storage power station model, providing inertia response and primary frequency regulation functions;

[0047] The energy storage power station frequency regulation control model construction module is configured to consider the impact of energy storage charging and discharging on the frequency regulation stability, and establish an adaptive frequency regulation control model that considers the energy storage charge state;

[0048] A power system frequency response model building module is configured to build a power system frequency response model based on the balance equations of wind, solar, hydro, and thermal power sources, energy storage units, and loads in the power system;

[0049] a frequency divider model building module configured to establish a frequency divider model based on the response characteristics of the energy storage unit, so that the energy storage unit bears the high-frequency component of the frequency deviation and other power sources bear the low-frequency component of the frequency deviation through the frequency divider model;

[0050] The power system frequency control operation module is configured to comprehensively establish a frequency control model considering frequency division frequency control of the energy storage power supply and other power supplies, and to realize frequency control of the power system.

[0051] In a third aspect, an electronic device is provided, comprising at least one processor, and a memory connected with the at least one processor in communication, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the steps of the method for frequency division frequency control of a power system with an energy storage unit according to any one of the embodiments of the present application.

[0052] In a fourth aspect, the present application further provides a computer readable storage medium having stored thereon a computer program, and the computer program instructions are executed by a processor to perform the steps of the method for frequency division frequency control of a power system with an energy storage unit according to any one of the embodiments of the present application.

[0053] The method and system for frequency division frequency control of a power system with an energy storage unit of the present application are based on an energy storage power station model, an energy storage power station comprehensive inertia control model is established, the influence of energy storage due to charging and discharging on frequency control stability is considered, an energy storage power station frequency control model considering the influence of state of charge is established, the energy storage power station has the ability of inertia response and primary frequency control, and the principle of time division and segmentation is adopted to prevent the deterioration of state of charge caused by overcharging and overdischarging of the energy storage, and the influence on frequency control output stability is avoided. Based on the balance equation of wind, light, water and fire power sources, energy storage units and loads in the power system, a frequency response model of the power system is established, a frequency divider model is established based on the response characteristics of the energy storage unit, the energy storage unit is made to bear the high frequency component of the frequency deviation through the frequency divider model, and the other power sources bear the low frequency component of the frequency deviation, the frequency division control of the energy storage unit and other types of power sources is realized, the advantages of the energy storage unit are brought into play, and the frequency characteristics of the power system are improved. The present application is beneficial to bring into play the frequency control advantages of the energy storage unit power source such as fast response speed and the ability to suppress frequency high frequency fluctuation, and is beneficial to improve the frequency response speed of the power system and the frequency response ability of the power system. BRIEF DESCRIPTION OF DRAWINGS

[0054] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0055] Figure 1 A flowchart of a method for frequency division frequency control of a power system with an energy storage unit according to an embodiment of the present application is provided.

[0056] Figure 2A structural block diagram of a power system frequency division and frequency modulation control system including an energy storage unit provided in one embodiment of the present invention;

[0057] Figure 3 is a structural diagram of an electronic device provided by an embodiment of the present invention;

[0058] Figure 4 A frequency response framework diagram of a power system frequency division and frequency modulation control system including an energy storage unit provided in one embodiment of the present invention;

[0059] Figure 5 A comparison diagram of the frequency modulation effects of frequency division and frequency modulation control of a power system including an energy storage unit provided in one embodiment of the present invention. DETAILED DESCRIPTION

[0060] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0061] See also Figure 1 , which shows a flow chart of a frequency division and frequency modulation control method for a power system containing an energy storage unit of the present application.

[0062] like Figure 1 As shown, a method for controlling frequency division and frequency modulation of a power system including an energy storage unit specifically includes the following steps:

[0063] Step S1: Based on the energy storage power station model, a comprehensive inertial control model of the energy storage power station is established to provide inertial response and primary frequency regulation functions;

[0064] Step S2: Considering the impact of energy storage on the frequency modulation stability caused by charging and discharging, an adaptive frequency modulation control model considering the energy storage charge state is established;

[0065] Step S3: Establishing a frequency response model of the power system based on the balance equations of wind, solar, hydro, and thermal power sources, energy storage units, and loads in the power system;

[0066] Step S4: Based on the response characteristics of the energy storage unit, a frequency divider model is established, and the frequency divider model is used to 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;

[0067] Step S5: A frequency control model is comprehensively established that takes into account the frequency division and frequency modulation of the energy storage power source and other power sources to realize the frequency modulation control of the power system.

[0068] In some embodiments, step S1 is specifically the following steps:

[0069] Step S101: For the frequency regulation problem, the energy storage power station is modeled as a first-order dynamic model, which is expressed as follows:

[0070] ;

[0071] Where: is the output power of the energy storage power station; Receive power reference value from controller for energy storage power station; is the time constant of the energy storage power station; s is the differential operator;

[0072] Step S102: In order to enable the energy storage power station to have the functions of inertial response and primary frequency regulation, a comprehensive inertial control model of the energy storage power station is established. The formula is expressed as follows:

[0073] ;

[0074] Where: 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; It is the high-frequency component of the power system frequency fluctuation.

[0075] In some embodiments, step S2 is specifically the following steps:

[0076] Step S201: Considering the impact of the discharge depth of the energy storage power station on the frequency modulation output, an adaptive frequency modulation control model considering the energy storage charge state is established, and the comprehensive inertia controller coefficient is adaptively adjusted according to the energy storage charge state;

[0077] Step S202: The formula for the droop coefficient of the adaptive integrated inertia controller considering the energy storage charge state is expressed as:

[0078] ;

[0079] Where: is the initial droop coefficient of the energy storage integrated inertia controller; The charging state of the energy storage power station; is the average state of charge of the energy storage power station; e is a natural constant, is the power system frequency deviation;

[0080] Step S203: Considering the different frequency regulation requirements during the frequency deterioration and frequency recovery processes of the power system frequency dynamic change process, in order to suppress frequency deterioration and accelerate frequency recovery during the frequency response process, different integrated inertia controller differential coefficients are used to perform frequency regulation during the frequency deterioration and frequency recovery processes;

[0081] The frequency deterioration process is short in time, and the frequency change needs to be suppressed in a short time, so the influence of the state of charge is ignored, and ;

[0082] In the frequency recovery process, the recovery speed is slow, so the adaptive comprehensive inertia controller differential coefficient considering the state of charge of the energy storage is:

[0083] ;

[0084] In the formula: is the initial droop coefficient of the energy storage comprehensive inertia controller; is the maximum state of charge of the energy storage power station; is the minimum state of charge of the energy storage power station.

[0085] In some embodiments, step S3 is specifically the following step:

[0086] Step S301: Based on the dynamic balance equation of each type of power source and load power in the power system, when power imbalance occurs on the power generation side and the load side, the power system frequency response model is established according to the swing equation of the power system frequency, and the formula is expressed as:

[0087] ;

[0088] In the formula: , , , and respectively represent the change value 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.

[0089] In some embodiments, step S4 is specifically the following step:

[0090] Step S401: In order to fully exert the role of the energy storage power station power source, a frequency divider model is established, the frequency deviation of the power system is divided into low frequency components and high frequency components through the frequency division channel, and is allocated to different power sources to make each type of power source exert the frequency modulation potential, and the formula of the frequency divider model is expressed as:

[0091] Low frequency component channel of the frequency divider model:

[0092] ;

[0093] 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;

[0094] Crossover model high frequency component channel:

[0095] ;

[0096] After the frequency deviation signal of the power system is divided by the low-frequency component channel and the high-frequency component channel of the divider, it is not attenuated. The frequency deviation output by the divider model satisfies:

[0097] ;

[0098] Therefore, the divider model does not affect the actual demand for power system frequency regulation;

[0099] Through the divider model, the energy storage unit bears the high-frequency component of the frequency deviation, while other power sources bear the low-frequency component of the frequency deviation, giving full play to the frequency regulation advantages of various types of power sources.

[0100] In some embodiments, step S5 is specifically the following steps:

[0101] Based on the adaptive frequency modulation control model considering the energy storage charge state and the power system frequency response model, the output of the high-frequency component channel of the power system frequency deviation is combined with the adaptive frequency modulation control model considering the energy storage charge state to establish a closed-loop frequency control link of the energy storage power station, so as to realize the power supply's suppression of high-frequency fluctuations; the output of the low-frequency component channel of the power system frequency deviation is combined with the frequency control model of other power supply frequency division modulation to establish a closed-loop control link, which is responsible for low-frequency power fluctuations; finally, the frequency regulation of the power system is realized based on the power system frequency swing control equation.

[0102] In summary, the method of the present application constructs a comprehensive inertial control model for an energy storage power station, establishes a frequency regulation control model for an energy storage power station that takes into account the influence of the state of charge, and adopts the principle of time-sharing and segmentation to avoid the influence of the state of charge on the stability of the frequency regulation output when the energy storage is overcharged or over-discharged. A frequency response model of the system is established, and a divider model is established based on the response characteristics of the energy storage unit, thereby realizing frequency division control of the energy storage unit and other types of power supplies, giving full play to the advantages of the energy storage unit, and improving the frequency characteristics of the system. The present invention is conducive to giving full play to the frequency regulation advantages of the energy storage unit power supply in suppressing high-frequency frequency fluctuations, and is conducive to improving the frequency response speed of the system and improving the frequency response performance of the system.

[0103] See also Figure 2 , which shows a structural block diagram of a power system frequency division and frequency modulation control system containing an energy storage unit of the present application.

[0104] like Figure 2As shown, the power system frequency division and frequency regulation control system 200 containing energy storage units includes an energy storage power station comprehensive inertia control model construction module 210, an energy storage power station frequency regulation control model construction module 220, a power system frequency response model construction module 230, a divider model construction module 240 and a power system frequency regulation control operation module 250.

[0105] The energy storage power station integrated inertia control model construction module is configured to establish an integrated inertia control model of the energy storage power station based on the energy storage power station model, providing inertia response and primary frequency regulation functions;

[0106] The energy storage power station frequency regulation control model construction module is configured to consider the impact of energy storage charging and discharging on the frequency regulation stability, and establish an adaptive frequency regulation control model that considers the energy storage charge state;

[0107] A power system frequency response model building module is configured to build a power system frequency response model based on the balance equations of wind, solar, hydro, and thermal power sources, energy storage units, and loads in the power system;

[0108] a frequency divider model building module configured to establish a frequency divider model based on the response characteristics of the energy storage unit, so that the energy storage unit bears the high-frequency component of the frequency deviation and other power sources bear the low-frequency component of the frequency deviation through the frequency divider model;

[0109] The power system frequency regulation control operation module is configured to comprehensively establish a frequency control model that takes into account the frequency division and frequency regulation of energy storage power sources and other power sources, so as to realize the frequency regulation control of the power system.

[0110] Among them, the energy storage power station comprehensive inertia control model construction module 210 is configured to consider the impact of the frequency regulation continuity and stability caused by the charging and discharging of energy storage, and establish an adaptive frequency regulation control model considering the energy storage charge state; the energy storage power station frequency regulation control model construction module 220 is configured to consider the impact of the frequency regulation continuity and stability caused by the charging and discharging of energy storage, and establish an adaptive frequency regulation control model considering the energy storage charge state; the power system frequency response model construction module 230 is configured to establish a power system frequency response model based on the balance equations of wind, solar, hydro, and thermal power sources, energy storage units, and loads in the power system; the divider model construction module 240 is configured to establish a divider model based on the response characteristics of the energy storage unit, through which the energy storage unit bears the high-frequency component of the frequency deviation, while other power sources bear the low-frequency component of the frequency deviation; the power system frequency regulation control operation module 250 is configured to comprehensively establish a frequency control model that considers the frequency division and frequency regulation of the energy storage power source and other power sources to achieve frequency regulation control of the power system.

[0111] It should be understood that Figure 2 Modules and references documented in Figure 1Therefore, the operations and features described above for the method and the corresponding technical effects also apply to Figure 2 The modules in it will not be described in detail here.

[0112] In some embodiments, an embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, wherein 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 containing an energy storage unit in any of the above method embodiments;

[0113] As an embodiment, the computer-readable storage medium of the present invention stores computer-executable instructions, and the computer-executable instructions are configured as follows:

[0114] Based on the energy storage power station model, a comprehensive inertial control model of the energy storage power station is established to provide inertial response and primary frequency regulation functions;

[0115] Considering the impact of energy storage charging and discharging on the frequency modulation stability, an adaptive frequency modulation control model considering the energy storage charge state is established;

[0116] Based on the balance equations of wind, solar, hydro and thermal power sources, energy storage units and loads in the power system, a frequency response model of the power system is established;

[0117] Based on the response characteristics of the energy storage unit, a frequency divider model is established. Through the frequency divider model, the energy storage unit bears the high-frequency component of the frequency deviation, while other power sources bear the low-frequency component of the frequency deviation;

[0118] A comprehensive frequency control model considering the frequency division and frequency modulation of energy storage power sources and other power sources is established to realize the frequency modulation control of the power system.

[0119] The computer-readable storage medium may include a program storage area and a data storage area. The program storage area may store an operating system and application programs required for at least one function; the data storage area may store data generated based on the use of a power system frequency modulation control system including an energy storage unit. Furthermore, the computer-readable storage medium may include high-speed random access memory and may also include memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state memory device.

[0120] In some embodiments, the computer-readable storage medium may optionally include a memory remotely located from the processor. Such remote memory may be connected to the power system frequency modulation and control system including the energy storage unit via a network. Examples of such a network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0121] Figure 3Schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. Figure 3 As shown, the device includes: a processor 310 and a memory 320. The electronic device may also 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 may be connected via a bus or other means. Figure 3 The example of the connection via bus is taken. The memory 320 is the computer-readable storage medium mentioned above. The processor 310 executes various functional applications and data processing of the server by running the non-volatile software programs, instructions and modules stored in the memory 320, that is, implements the above-mentioned method embodiment of a power system frequency division and frequency modulation control method containing an energy storage unit. The input device 330 can receive input digital or character information, and generate key signal input related to user settings and function control of a power system frequency division and frequency modulation control system containing an energy storage unit. The output device 340 may include a display device such as a display screen.

[0122] The electronic device can execute the method provided by the embodiment of the present invention, and has the functional modules and beneficial effects corresponding to the execution method. For technical details not fully described in this embodiment, please refer to the method provided by the embodiment of the present invention.

[0123] As an embodiment, the above-mentioned electronic device is applied to a power system frequency division and frequency modulation control system containing an energy storage unit, 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 that can be executed 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 containing the energy storage unit.

[0124] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion 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, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods of each embodiment or certain portions of the embodiments.

[0125] The present invention Figure 4 The design of the embodiment is verified in the power system frequency response model shown in FIG. Figure 5 The figure shows the comparison of the frequency modulation effect of an embodiment of the present invention. Figure 5It can be seen that the power system frequency division and frequency modulation control method containing energy storage units proposed in the present invention has smaller power system frequency fluctuation and better power system frequency response performance than the traditional frequency control method.

[0126] 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 it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A frequency division and frequency modulation control method for a power system including an energy storage unit, characterized in that: The following steps are involved: Step S1: Based on the energy storage power station model, a comprehensive inertial control model of the energy storage power station is established to provide inertial response and primary frequency regulation functions; Step S2: Considering the impact of energy storage on the frequency modulation stability caused by charging and discharging, an adaptive frequency modulation control model considering the energy storage charge state is established; Step S3: Establishing a frequency response model of the power system based on the balance equations of wind, solar, hydro, and thermal power sources, energy storage units, and loads in the power system; Step S4: Based on the response characteristics of the energy storage unit, a frequency divider model is established, and the frequency divider model is used to 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; The specific steps are as follows: Step S401: To fully utilize the power source of the energy storage station, a frequency divider model is established. The frequency deviation of the power system is divided into low-frequency components and high-frequency components through the frequency division channel. The components are then allocated to different power sources to enable each type of power source to realize its frequency regulation potential. The formula of the frequency divider model is expressed as follows: Crossover model low frequency component channel: ； Where: It is the low-frequency component of the power system frequency fluctuation; is the cutoff frequency of the low-frequency component channel of the crossover; Crossover model high frequency component channel: ； The output frequency deviation of the frequency divider model satisfies: ； Through the frequency divider model, the energy storage unit bears the high-frequency component of the frequency deviation, while other power sources bear the low-frequency component of the frequency deviation; Step S5: A frequency control model is comprehensively established that takes into account the frequency division and frequency modulation of the energy storage power source and other power sources to realize the frequency modulation control of the power system.

2. A method for controlling frequency division and frequency modulation of a power system containing an energy storage unit according to claim 1, characterized in that: Step S1 specifically includes the following steps: Step S101: For the frequency regulation problem, the energy storage power station is modeled as a first-order model, and the formula is expressed as follows: ； Where: is the output power of the energy storage power station; Receive power reference value from controller for energy storage power station; 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 inertial response and primary frequency regulation, a comprehensive inertial control model of the energy storage power station is established. The formula is expressed as follows: ； Where: 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; It is the high-frequency component of the power system frequency fluctuation.

3. A method for controlling frequency division and frequency modulation of a power system containing 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 modulation output, an adaptive frequency modulation control model considering the energy storage charge state is established, and the comprehensive inertia controller coefficient is adaptively adjusted according to the energy storage charge state; Step S202: The formula for the droop coefficient of the adaptive integrated inertia controller considering the energy storage charge state is expressed as: ； Where: is the initial droop coefficient of the energy storage integrated inertia controller; The charging state of the energy storage power station; is the average state of charge of the energy storage power station; e is a natural constant, is the power system frequency deviation; Step S203: considering the different frequency regulation requirements during the frequency deterioration and frequency recovery process of the power system frequency dynamic change process, different integrated inertia controller differential coefficients are used to perform frequency regulation during the frequency deterioration and frequency recovery processes; During the frequency degradation process, the impact of the charge state change is ignored, and ; During the frequency recovery process, the differential coefficient of the adaptive integrated inertia controller considering the energy storage charge state is: ； Where: is the initial droop coefficient of the energy storage integrated inertia controller; The maximum state of charge of the energy storage power station; It is the minimum state of charge of the energy storage station.

4. A method for controlling frequency division and frequency modulation of a power system containing an energy storage unit according to claim 3, characterized in that: Step S3 specifically includes the following steps: Step S301: Based on the dynamic balance equations of power of various types of power sources and loads in the power system, when power imbalance occurs between the generation side and the load side, a power system frequency response model is established according to the swing equation of the power system frequency. The formula is expressed as follows: ； Where: 、 、 、 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 power system.

5. A method for controlling frequency division and frequency modulation of a power system containing an energy storage unit according to claim 4, characterized in that: Step S5 is specifically the following steps: Based on the adaptive frequency modulation control model considering the energy storage charge state and the power system frequency response model, the output of the high-frequency component channel of the power system frequency deviation is combined with the adaptive frequency modulation control model considering the energy storage charge state to establish a closed-loop frequency control link of the energy storage power station, so as to realize the power supply's suppression of high-frequency fluctuations; the output of the low-frequency component channel of the power system frequency deviation is combined with the frequency control model of other power supply frequency division modulation to establish a closed-loop control link, which is responsible for low-frequency power fluctuations; finally, the frequency regulation of the power system is realized based on the power system frequency swing control equation.

6. A power system frequency division and frequency modulation control system containing an energy storage unit, characterized in that: include: The energy storage power station integrated inertia control model construction module is configured to establish an integrated inertia control model of the energy storage power station based on the energy storage power station model, providing inertia response and primary frequency regulation functions; The energy storage power station frequency regulation control model construction module is configured to consider the impact of energy storage charging and discharging on the frequency regulation stability, and establish an adaptive frequency regulation control model that considers the energy storage charge state; A power system frequency response model building module is configured to build a power system frequency response model based on the balance equations of wind, solar, hydro, and thermal power sources, energy storage units, and loads in the power system; a frequency divider model building module configured to establish a frequency divider model based on the response characteristics of the energy storage unit, so that the energy storage unit bears the high-frequency component of the frequency deviation and other power sources bear the low-frequency component of the frequency deviation through the frequency divider model; The power system frequency regulation control operation module is configured to comprehensively establish a frequency control model that takes into account the frequency division and frequency regulation of energy storage power sources and other power sources, so as to realize the frequency regulation control of the power system.

7. An electronic device, characterized in that: include: 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 to enable the at least one processor to perform the method according to any one of claims 1 to 5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

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