CN116599084A

CN116599084A - Frequency modulation method, frequency modulation device and storage medium of wind-solar-energy-storage combined power generation system

Info

Publication number: CN116599084A
Application number: CN202310645161.5A
Authority: CN
Inventors: 付超; 唐飞; 刘卓; 朱泽翔; 周保荣; 姚文峰; 亓君锋; 杨荣照; 刘宇明; 谢宇翔; 吴为; 张文壕
Original assignee: Wuhan University WHU; CSG Electric Power Research Institute
Current assignee: Wuhan University WHU; CSG Electric Power Research Institute
Priority date: 2023-05-31
Filing date: 2023-05-31
Publication date: 2023-08-15

Abstract

The application provides a frequency modulation method, a frequency modulation device and a storage medium of a wind-solar-energy-storage combined power generation system, which are used for acquiring the frequency change rate of an alternating current bus under the condition that the alternating current bus is subjected to active power disturbance; under the condition that the frequency change rate is greater than zero, the energy storage system is controlled to operate by adopting a first control strategy until the frequency change rate is equal to zero, wherein the first control strategy is to gradually reduce the virtual inertia control coefficient in the first power function and gradually increase the droop control coefficient in the first power function; and under the condition that the frequency change rate is equal to zero, controlling the energy storage system to operate by adopting a second control strategy until the frequency change rate is within a preset frequency change rate range, wherein the second control strategy is that a droop control coefficient in a second power function is determined by frequency deviation. The method solves the problem that the frequency adjustment mode of the existing wind-solar-energy-storage combined power generation system does not consider the primary and secondary aspects of virtual inertial control or droop control in different frequency adjustment stages.

Description

Frequency modulation method, frequency modulation device and storage medium of wind-solar-energy-storage combined power generation system

Technical Field

The application relates to the technical field of power systems, in particular to a frequency modulation method of a wind-solar-energy-storage combined power generation system, a frequency modulation device of the wind-solar-energy-storage combined power generation system, a storage medium, a processor and electronic equipment.

Background

As shown in fig. 1, the control strategy of the existing wind-solar energy-storage combined power generation system mostly utilizes the dominant characteristics of the energy storage system, designs a single energy storage frequency modulation strategy, such as only adopting virtual inertial control or only adopting droop control to participate in the frequency adjustment of the wind-solar energy-storage combined power generation system, that is, the frequency adjustment mode of the existing wind-solar energy-storage combined power generation system does not consider the problem that the virtual inertial control or the droop control is divided into primary and secondary in different frequency modulation stages.

In addition, the energy storage participation frequency adjustment mode in the existing wind-solar-energy-storage combined power generation system is mainly based on the protection of the SOC of the energy storage system, is not related to the actual frequency deterioration degree, adopts specific mathematical functions, and is various in advantages and disadvantages, difficult to evaluate and applicable to be evaluated.

Disclosure of Invention

The application mainly aims to provide a frequency modulation method of a wind-solar combined power generation system, a frequency modulation device of the wind-solar combined power generation system, a storage medium, a processor and electronic equipment, so as to at least solve the problem that the frequency adjustment mode of the traditional wind-solar combined power generation system does not consider the primary and secondary aspects of virtual inertial control or sagging control in different frequency modulation stages.

In order to achieve the above object, according to one aspect of the present application, there is provided a frequency modulation method of a wind-solar-energy-storage combined power generation system including a wind power generation system, a photovoltaic power generation system, an energy storage system, and an ac bus, the wind power generation system, the photovoltaic power generation system, and the energy storage system being electrically connected to the ac bus, respectively, the ac bus being electrically connected to a power grid, the method comprising: under the condition that active power disturbance occurs to the alternating current bus, acquiring the frequency change rate of the alternating current bus; when the frequency change rate is greater than zero, a first control strategy is adopted to control the energy storage system to operate until the frequency change rate is equal to zero, wherein the first control strategy is to gradually reduce a virtual inertia control coefficient in a first power function and gradually increase a droop control coefficient in the first power function, and the first power function is a functional relation between the active force of the energy storage system, the frequency change rate and the frequency deviation of the alternating current bus; and under the condition that the frequency change rate is equal to zero, controlling the energy storage system to operate by adopting a second control strategy until the frequency change rate is within a preset frequency change rate range, wherein the second control strategy is that a droop control coefficient in a second power function is determined by the frequency deviation, and the second power function is a functional relation between the frequency deviation and the active power of the energy storage system.

Optionally, in a case where the frequency change rate is greater than zero, controlling the operation of the energy storage system by using a first control strategy until the frequency change rate is equal to zero includes: in the case that the rate of change of the frequency is greater than zero, according toControlling the operation of the energy storage system, wherein P _bess-fina For the active force of the energy storage system, df/dt is the frequency change rate, Δf is the frequency deviation, K _I0 For presetting virtual inertia control coefficient, K _D0 To preset the sagging control coefficient, k ₀ For a first preset value, m ₀ Is a second preset value, K _comp For a compensation coefficient, the compensation coefficient is determined by the frequency deviation and an SOC value of the energy storage system.

Optionally, under the condition that the frequency change rate is equal to zero, controlling the energy storage system to operate by adopting a second control strategy until the frequency change rate is within a preset frequency change rate range, including: in the case that the rate of change of the frequency is equal to zero, according toControlling the operation of the energy storage system, wherein P _bess-fina For the active force of the energy storage system, df/dt is the frequency change rate, Δf is the frequency deviation, Δf _max K is the maximum value of the frequency deviation _I0 For presetting virtual inertia control coefficient, K _D0 To preset the sagging control coefficient, k ₁ For a third preset value, m ₁ For a fourth preset value, K _comp For a compensation coefficient, the compensation coefficient is determined by the frequency deviation and an SOC value of the energy storage system.

Optionally, the method comprises: and inputting the frequency deviation and the SOC value into a fuzzy logic controller to obtain the compensation coefficient.

Optionally, the working process of the fuzzy logic controller includes: performing fuzzification processing on the SOC value based on a first preset membership function to obtain a first membership degree, and performing fuzzification processing on the frequency deviation based on a second preset membership function to obtain a second membership degree; determining a compensation membership function based on the first membership, the second membership, a third preset membership function and a control rule of the fuzzy logic controller, wherein the compensation membership function is a function with independent variables as the compensation coefficient; and solving the compensation membership function by adopting a gravity center method to obtain the compensation coefficient.

Optionally, the control rule of the fuzzy logic controller is a mapping relation table: the mapping relation table characterizes the mapping relation between the frequency deviation and the SOC value and the compensation coefficient, when the frequency deviation is a negative value and the SOC value is fixed, the absolute value of the frequency deviation is larger, the compensation coefficient is larger, and when the frequency deviation is a negative value and the frequency deviation is fixed, the SOC value is larger, and the compensation coefficient is larger; the larger the frequency deviation is, the larger the compensation coefficient is, when the frequency deviation is a positive value and the SOC value is fixed, and the smaller the SOC value is, the larger the compensation coefficient is, when the frequency deviation is a positive value and the frequency deviation is fixed.

According to still another aspect of the present application, there is provided a frequency modulation device of a wind-solar-energy-storage combined power generation system, the wind-solar-energy-storage combined power generation system including a wind power generation system, a photovoltaic power generation system and an energy storage system, the wind power generation system, the photovoltaic power generation system and the energy storage system being respectively electrically connected with an ac bus, the ac bus being electrically connected with a power grid, the device comprising: the acquisition unit is used for acquiring the frequency change rate of the alternating current bus under the condition that the alternating current bus is subjected to active power disturbance; the first control unit is used for controlling the energy storage system to operate by adopting a first control strategy under the condition that the frequency change rate is larger than zero until the frequency change rate is equal to zero, wherein the first control strategy is to gradually reduce a virtual inertia control coefficient in a first power function and gradually increase a sagging control coefficient in the first power function, and the first power function is a functional relation between the active output of the energy storage system and the frequency change rate and the frequency deviation of the alternating current bus; and the second control unit is used for controlling the energy storage system to operate by adopting a second control strategy under the condition that the frequency change rate is equal to zero until the frequency of the wind-solar-storage combined power generation system is kept stable, wherein the second control strategy is that a sagging control coefficient in a second power function is determined by the frequency deviation, and the second power function is a functional relation between the frequency deviation and the active power output of the energy storage system.

According to still another aspect of the present application, there is provided a computer readable storage medium, where the computer readable storage medium includes a stored program, and when the program runs, the device in which the computer readable storage medium is located is controlled to execute any one of the frequency control methods of the wind-solar-energy-storage combined power generation system.

According to still another aspect of the present application, there is provided a processor for running a program, wherein the program runs to execute any one of the frequency control methods of the wind-solar-energy-storage combined power generation system.

According to an aspect of the present application, there is provided an electronic apparatus including: the wind and solar energy storage cogeneration system comprises one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs comprising a frequency control method for executing any one of the wind and solar energy storage cogeneration systems.

By applying the technical scheme of the application, under the condition that the frequency change rate is larger than zero, namely in an inertia response stage, virtual inertia control is taken as a main component, sagging control is taken as an auxiliary component, and sagging control is adopted in a primary frequency modulation stage, so that the problem that the frequency adjustment mode of the traditional wind-solar-energy-storage combined power generation system does not consider the main component and the secondary component of the virtual inertia control or the sagging control in different frequency modulation stages is solved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:

FIG. 1 is a schematic diagram of a frequency response model for energy storage participation wind-solar energy-storage power generation system frequency adjustment using single virtual inertial control or droop control according to embodiments of the present application;

fig. 2 is a block diagram of a hardware structure of a mobile terminal for performing a frequency modulation method of a wind-solar hybrid power generation system according to an embodiment of the present application;

fig. 3 shows a flow chart of a frequency modulation method of a wind-solar-energy-storage combined power generation system according to an embodiment of the application;

fig. 4 shows a schematic diagram of a wind-solar-energy-storage combined power generation system according to an embodiment of the application.

FIG. 5 is a schematic diagram of a frequency response model for energy storage participation in wind-solar energy storage power generation system frequency adjustment taking into account primary and secondary fractions of virtual inertial control or droop control in different frequency modulation phases provided in an embodiment according to the present application;

FIG. 6 is a schematic diagram showing a matching relationship of an SOC value, a frequency deviation, and a compensation coefficient provided in an embodiment according to the present application;

FIG. 7 is a schematic diagram showing a graph of a first preset membership function provided in an embodiment in accordance with the present application;

FIG. 8 is a schematic diagram showing a plot of a second preset membership function provided in an embodiment in accordance with the present application;

FIG. 9 is a schematic diagram showing a curve of a third preset membership function provided in an embodiment in accordance with the present application;

fig. 10 is a schematic diagram showing a frequency characteristic curve of a wind-solar-energy-storage combined power generation system according to an embodiment of the present application;

FIG. 11 shows a schematic diagram of a control coefficient variation provided in an embodiment in accordance with the application;

FIG. 12 (a) is a schematic diagram showing an input curve of a fuzzy logic controller provided in accordance with an embodiment of the present application;

FIG. 12 (b) is a schematic diagram showing an input curve of another fuzzy logic controller provided in accordance with an embodiment of the present application;

FIG. 12 (c) is a schematic diagram showing an output curve of a fuzzy logic controller provided in accordance with an embodiment of the present application;

FIG. 12 (d) is a schematic diagram illustrating an active force curve of an energy storage system provided in accordance with an embodiment of the present application;

Fig. 13 shows a block diagram of a frequency modulation device of a wind-solar-energy-storage combined power generation system according to an embodiment of the application.

Detailed Description

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. The application will be described in detail below with reference to the drawings in connection with embodiments.

In order that those skilled in the art will better understand the present application, a technical solution in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present application without making any inventive effort, shall fall within the scope of the present application.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate in order to describe the embodiments of the application herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

For convenience of description, the following will describe some terms or terminology involved in the embodiments of the present application:

active power disturbance: it refers to sudden events or faults in the power system that cause active power changes in the grid, such as sudden increases or decreases in load, generator disturbances, etc., which cause grid frequency fluctuations and stability problems.

Fuzzy logic controller: the fuzzy controller is based on fuzzy logic, and is more suitable for systems which are difficult to model or are inaccurate in model compared with the traditional controller by representing both input variables and output variables as fuzzy quantities and using fuzzy reasoning to realize control on complex systems.

As described in the background art, the frequency adjustment mode of the existing wind-light-storage combined power generation system does not consider the primary and secondary of virtual inertia control or droop control in different frequency modulation stages, so as to solve the problem that the frequency adjustment mode of the existing wind-light-storage combined power generation system does not consider the primary and secondary of virtual inertia control or droop control in different frequency modulation stages.

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application.

The method embodiments provided in the embodiments of the present application may be performed in a mobile terminal, a computer terminal or similar computing device. Taking the mobile terminal as an example, fig. 2 is a block diagram of a hardware structure of the mobile terminal of a frequency modulation method of a wind-solar-energy-storage combined power generation system according to an embodiment of the present application. As shown in fig. 2, the mobile terminal may include one or more (only one is shown in fig. 2) processors 102 (the processor 102 may include, but is not limited to, a microprocessor MCU or a processing device such as a programmable logic device FPGA) and a memory 104 for storing data, wherein the mobile terminal may further include a transmission device 106 for communication functions and an input-output device 108. It will be appreciated by those skilled in the art that the structure shown in fig. 2 is merely illustrative and not limiting of the structure of the mobile terminal described above. For example, the mobile terminal may also include more or fewer components than shown in fig. 2, or have a different configuration than shown in fig. 2.

The memory 104 may be used to store a computer program, for example, a software program of application software and a module, such as a computer program corresponding to a display method of device information in an embodiment of the present application, and the processor 102 executes the computer program stored in the memory 104 to perform various functional applications and data processing, that is, to implement the above-described method. Memory 104 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include memory remotely located relative to the processor 102, which may be connected to the mobile terminal via a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof. The transmission means 106 is arranged to receive or transmit data via a network. Specific examples of the network described above may include a wireless network provided by a communication provider of the mobile terminal. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, simply referred to as NIC) that can connect to other network devices through a base station to communicate with the internet. In one example, the transmission device 106 may be a Radio Frequency (RF) module, which is used to communicate with the internet wirelessly.

In this embodiment, a method for tuning a wind-solar energy storage cogeneration system operating on a mobile terminal, a computer terminal, or a similar computing device is provided, and it should be noted that the steps illustrated in the flowchart of the figures may be performed in a computer system such as a set of computer executable instructions, and that although a logical sequence is illustrated in the flowchart, in some cases, the steps illustrated or described may be performed in a different order than that illustrated herein.

FIG. 3 is a flow chart of a frequency modulation method of a wind-solar-energy-storage cogeneration system according to an embodiment of the application. As shown in fig. 3, the method comprises the steps of:

step S201, when active power disturbance occurs to the AC bus, obtaining the frequency change rate of the AC bus;

specifically, as shown in fig. 4, the wind-solar-energy-storage combined power generation system comprises a wind power generation system E2, a photovoltaic power generation system E1, an energy storage system E3 and an alternating current bus B9, wherein the wind power generation system E2, the photovoltaic power generation system E1 and the energy storage system E3 are respectively and electrically connected with the alternating current bus B9, the alternating current bus B9 is electrically connected with a power grid, the wind-solar-energy-storage combined power generation system further comprises a transformer T3, a transformer T4, a node B3 and a node B10, the power grid comprises a transformer T1, a transformer T2, nodes B1, B2, B4, B5, B6, B7 and B8, and synchronous units G1 and G2 and loads L1, L2 and L3.

Specifically, the frequency of the ac bus is the frequency of the power grid.

Step S202, when the frequency change rate is greater than zero, controlling the energy storage system to operate by adopting a first control strategy until the frequency change rate is equal to zero, wherein the first control strategy is to gradually reduce a virtual inertia control coefficient in a first power function and gradually increase a sagging control coefficient in the first power function, and the first power function is a functional relation between the active power output of the energy storage system and the frequency change rate and the frequency deviation of the alternating current bus;

specifically, under the condition that the frequency change rate is greater than zero, determining that the frequency modulation stage is in an inertial response stage, and at the moment, adopting a first control strategy to control the operation of the energy storage system, namely leading virtual inertial control in the inertial response stage, slowing down the frequency dropping speed (frequency change rate), and improving the frequency lowest point of the alternating current bus.

Specifically, according to the frequency response model of the wind-solar energy storage power generation system with energy storage in fig. 1, neglecting the first-order filter expression, and listing the frequency domain expressions of the frequency deviation after the energy storage participates in frequency control by respectively matching with the synchronous machine set:

Wherein H is equivalent inertial time constant of the synchronous machine set, D is equivalent damping of the synchronous machine set, R is droop coefficient of the speed regulator, and delta P is calculated by the method _L K is active power disturbance _I K is a virtual inertial control coefficient _D For primary frequency modulation droop control factor, ΔF ^I (s) is the frequency deviation after virtual inertia control, ΔF ^D (s) is the frequency deviation after primary frequency modulation droop control, and the maximum value and the steady-state frequency deviation of the frequency change rates of the two control modes are obtained after the Laplace initial value and the final value theorem are as follows:

virtual inertial control:

primary frequency modulation droop control:

wherein, roCoF _max The SFD is the steady-state frequency deviation, which is the maximum value of the frequency change rate;

from the above, it can be seen that the maximum value of the frequency change rate depends on the virtual inertia control, that is, the energy storage system has a fast and accurate power response capability, so that the defect that the conventional unit is not good at fast response frequency change can be overcome, the steady-state frequency deviation depends on the primary frequency modulation droop control, that is, the energy storage system can also provide a large-capacity power support, and the transient process is the result of the structure of the combined action of the virtual inertia control and the primary frequency modulation droop control.

The step S202 may be implemented as:

In the case that the frequency change rate is greater than zero, according to P _bess-fina ＝K _comp ×P _bess-init ，Controlling the operation of the energy storage system, wherein P _bess-fina For the active force of the energy storage system, df/dt is the frequency change rate, Δf is the frequency deviation, K _I0 For presetting virtual inertia control coefficient, K _D0 To preset the sagging control coefficient, k ₀ For a first preset value, m ₀ Is a second preset value, K _comp The compensation coefficient is determined by the frequency deviation and the SOC value of the energy storage system.

In this embodiment, the first power function is P _bess-fina ＝K _comp ×P _bess-init ， For the virtual inertial control coefficient in the first power function,/->For the droop control coefficient in the first power function, the absolute value of the frequency change rate monotonically decreases to zero in the inertia response phase, the virtual inertia control intensity gradually decreases, the droop control intensity gradually increases, i.e. the virtual inertia control is led to be dominant in the inertia response phase, the frequency dropping speed (frequency change rate) is slowed down, the frequency minimum point of the alternating current bus is lifted, and in order to solve the problem that the energy storage participation frequency adjustment mode in the wind-solar energy storage combined power generation system in the prior art is mainly singly considering the protection of the SOC of the energy storage system and is not related to the actual frequency deterioration degree, a compensation coefficient is introduced, the compensation coefficient is formed by the frequency deviation and the SOC value of the energy storage system, the frequency deviation reflects the actual frequency deterioration degree, i.e. the active output of the energy storage system in the inertia response phase is also dependent on the compensation coefficient The energy storage system is enabled to adjust the active output of the energy storage system according to the frequency deterioration degree under the condition of maintaining the health state, so that the problem that the energy storage participation frequency adjustment mode in the wind-solar-energy-storage combined power generation system in the prior art is mainly the protection of the SOC of the energy storage system in single consideration is solved.

In particular, the method comprises the steps of,wherein k is ₀ The value is generally 0.5, so as to ensure that droop control is dominant at the moment of switching from the inertia response phase to the primary frequency modulation phase, m ₀ Should be positive, m ₀ Depending on the total inertia and the maximum possible load fluctuation of the wind-solar-energy-storage combined power generation system.

Step S203, when the frequency change rate is equal to zero, controlling the energy storage system to operate by using a second control strategy until the frequency change rate is within a preset frequency change rate range, where the second control strategy is that a droop control coefficient in a second power function is determined by the frequency deviation, and the second power function is a functional relationship between the frequency deviation and the active power of the energy storage system.

Specifically, under the condition that the frequency change rate is equal to zero, the frequency modulation stage is determined to be switched from the inertia response stage to the primary frequency modulation stage, and thereafter, the frequency change rate is smaller than zero, and the energy storage system is controlled to operate by adopting a second control strategy at the moment, namely, droop control is dominant in the primary frequency modulation stage, so that the frequency of the alternating current bus is recovered more quickly, and steady-state frequency deviation is reduced.

The step S203 may be implemented as:

in the case that the frequency change rate is equal to zero, according to P _bess-fina ＝K _comp ×P _bess-init ，Controlling the operation of the energy storage system, wherein P _bess-fina For the active force of the energy storage system, df/dt is the frequency change rate, and Δf is the frequency change rateFrequency deviation, Δf _max K is the maximum value of the frequency deviation _I0 For presetting virtual inertia control coefficient, K _D0 To preset the sagging control coefficient, k ₁ For a third preset value, m ₁ For a fourth preset value, K _comp The compensation coefficient is determined by the frequency deviation and the SOC value of the energy storage system.

In this embodiment, the second power function is P _bess-fina ＝K _comp ×P _bess-init ，In order to solve the problem that in the prior art, the energy storage participation frequency adjustment mode in the wind-solar combined power generation system is mainly the protection of the SOC of the single-consideration energy storage system, and is not related to the actual frequency deterioration degree, a compensation coefficient is introduced, the compensation coefficient is formed by the frequency deviation and the SOC value of the energy storage system, the frequency deviation reflects the actual frequency deterioration degree, namely, in the primary frequency modulation stage, the active output of the energy storage system is also dependent on the compensation coefficient, so that the active output of the energy storage system is adjusted according to the frequency deterioration degree under the condition that the energy storage system maintains the healthy state, and the problem that in the prior art, the energy storage participation frequency adjustment mode in the wind-solar combined power generation system is mainly the protection of the SOC of the single-consideration energy storage system is solved.

In particular, the method comprises the steps of,wherein k is ₁ The value is generally 0.5.

Specifically, a frequency response model of the wind-solar energy-storage power generation system frequency adjustment is finally obtained, wherein the frequency response model considers the primary and secondary energy storage participation of virtual inertia control and sagging control in different frequency adjustment stages, and the frequency response model is shown in fig. 5.

In an alternative, the method further comprises:

and inputting the frequency deviation and the SOC value into a fuzzy logic controller to obtain the compensation coefficient.

In this embodiment, in order to solve the problem that in the prior art, the protection of the SOC of the energy storage system is singly considered, the protection is not related to the actual frequency degradation degree, and specific mathematical functions are mostly adopted, the advantages and disadvantages of the functions are various and difficult to evaluate, and the applicability is to be evaluated, the application adopts the frequency deviation and the SOC value to jointly determine the compensation coefficient, thereby solving the problem that in the prior art, the protection of the SOC of the energy storage system is singly considered, the protection is not related to the actual frequency degradation degree, and the application adopts the fuzzy logic controller to monitor the SOC value and the frequency deviation of the energy storage system in real time, determine the compensation coefficient in real time, further promote the improvement of the frequency of the ac bus under the condition that the energy storage system is in safe health as much as possible, compared with the specific mathematical functions, the fuzzy logic controller has stronger fault tolerance to parameter selection, as shown in fig. 6, the input (SOC value and frequency deviation Δf) -output (compensation coefficient K _comp ) A relation diagram, according to which the fuzzy logic controller determines the compensation coefficient K based on the SOC value and the frequency deviation Deltaf _comp 。

In an alternative solution, the working process of the fuzzy logic controller includes:

performing fuzzification processing on the SOC value based on a first preset membership function to obtain a first membership degree, and performing fuzzification processing on the frequency deviation based on a second preset membership function to obtain a second membership degree;

specifically, the SOC value has a value range of [0,1]The SOC value is recorded as three fuzzy sets: { Low, medium, high }, abbreviated as { L, M, H }, the first preset membership function isC in the first preset membership function corresponding to each fuzzy set ₁ And c ₂ The values of (a) are different, as shown in FIG. 7Mu, show _L (SOC) is the curve of the first preset membership function corresponding to the fuzzy set L, mu _M (SOC) is a curve of a first preset membership function of the fuzzy set M, μ _H And (SOC) is a first preset membership function curve corresponding to the fuzzy set H, and the possibility that the SOC value belongs to each fuzzy set L, M, H is calculated by using the first preset membership function (joint Gaussian membership function) corresponding to each fuzzy set, so as to obtain the first membership corresponding to each fuzzy set, namely, the possibility that the SOC value is subjected to fuzzification processing to calculate the SOC value at each sampling moment belongs to three fuzzy sets L, M, H.

Specifically, the frequency deviation Δf has a value ranging from [ -0.5,0.5]In Hz, note Δf has seven fuzzy sets: { negative big, negative middle, negative small, normal, positive small, median, positive big }, abbreviated as { NL, NM, NS, O, PS, PM, PL }, the second preset membership function isThe values of a, b, c and d in the second preset membership functions corresponding to the fuzzy sets are different, as shown in FIG. 8, mu _NL (Δf) is a curve of a second preset membership function corresponding to the fuzzy set NL, μ _NM (Δf) is the curve of the second preset membership function corresponding to the fuzzy set NM, μ _NS (Δf) is the curve of the second preset membership function corresponding to the fuzzy set NS, μ _O (Δf) is the curve of the second preset membership function corresponding to fuzzy set O, μ _PS (Δf) is a curve of a second preset membership function corresponding to the fuzzy set PS, μ _PM (Δf) is a curve of a second preset membership function corresponding to the fuzzy set PM, μ _PL And (delta f) is a curve of a second preset membership function corresponding to the fuzzy set PL, and the probability that delta f belongs to each fuzzy set is calculated by using the second preset membership function (joint Gaussian membership function) of each fuzzy set to obtain the second membership corresponding to each fuzzy set, namely, the probability that the frequency deviation belongs to seven fuzzy sets is calculated by carrying out fuzzification processing on the frequency deviation.

Determining a compensation membership function based on the first membership, the second membership, a third preset membership function and a control rule of the fuzzy logic controller, wherein the compensation membership function is a function with independent variables being the compensation coefficients;

specifically, the compensation coefficient has a value range of [0,1.5]The compensation coefficient is recorded as five fuzzy sets: { minimum, small, medium, large, maximum }, abbreviated as { VS, S, M, L, VL }, a third predetermined membership function ofThe values of a, b and c in the third preset membership function of each fuzzy set are different, as shown in FIG. 9, μ _VS (K _comp ) A curve mu of a third preset membership function corresponding to the fuzzy set VS _S (K _comp ) A curve of a third preset membership function corresponding to the fuzzy set S, mu _M (K _comp ) A curve mu of a third preset membership function corresponding to the fuzzy set M _L (K _comp ) A curve of a third preset membership function corresponding to the fuzzy set L, mu _VL (K _comp ) And a curve of a third preset membership function corresponding to the fuzzy set VL.

In an alternative solution, the control rule of the fuzzy logic controller is a mapping table:

wherein the map represents a map between the frequency deviation and the SOC value and the compensation coefficient, and the larger the absolute value of the frequency deviation is, the larger the compensation coefficient is, and the larger the SOC value is, the larger the compensation coefficient is, when the frequency deviation is negative and the frequency deviation is fixed;

The larger the frequency deviation is, the larger the compensation coefficient is, when the frequency deviation is positive and the SOC value is fixed, and the smaller the SOC value is, the larger the compensation coefficient is, when the frequency deviation is positive and the frequency deviation is fixed.

In this embodiment, the control rule of the fuzzy logic controller is shown in table 1, and in the case that the frequency deviation is negative, the energy storage system needs to be discharged, at this time, the active output of the energy storage system is the discharge power of the energy storage system, and the greater the compensation coefficient, the greater the discharge power of the energy storage system, the control rule of the fuzzy logic controller is: when the frequency deviation is the same, if the SOC value is larger, the compensation coefficient is larger, so as to ensure that the electric quantity of the energy storage system is in a moderate state in the discharging process of the energy storage system, so as to ensure that the electric quantity of the energy storage system is not excessively insufficient in the discharging process of the energy storage system, if the SOC value is the same, the absolute value of the frequency deviation is larger (namely the frequency deterioration degree is larger), the compensation coefficient is larger, so as to accelerate the improvement of the frequency, and under the condition that the frequency deviation is positive, the energy storage system is required to be charged, at the moment, the active power of the energy storage system is the charging power of the energy storage system, the larger the compensation coefficient is, and the control rule of the fuzzy logic controller is as follows: when the frequency deviation is the same, if the SOC value is smaller, the compensation coefficient is larger to ensure that the electric quantity of the energy storage system is in a moderate state in the discharging process of the energy storage system, so as to ensure that the electric quantity of the energy storage system is not excessively saturated in the discharging process of the energy storage system, if the SOC value is the same, the absolute value of the frequency deviation is larger (namely, the frequency deterioration degree is larger), the compensation coefficient is larger to accelerate the improvement of the frequency, and at each moment, the control rule of the fuzzy logic controller fully considers the matching of the frequency deviation and the SOC value, for example, if the SOC value is smaller (namely, the electric quantity of the energy storage system is insufficient) in the case of the negative frequency deviation, if the absolute value of the frequency deviation is smaller (namely, the electric quantity of the energy storage system is smaller), at the moment, the compensation coefficient is smaller (namely, the discharging power of the energy storage system is smaller) so as to ensure that the electric quantity of the energy storage system is not excessively insufficient, and if at the moment, the absolute value of the frequency deviation is larger (frequency deterioration is serious), even if the frequency deviation is smaller (the electric quantity of the energy storage system is insufficient), the frequency is improved, and the compensation coefficient is larger at the moment.

Table 1 control rule table of fuzzy logic controller

And solving the compensation membership function by adopting a gravity center method to obtain the compensation coefficient.

In the present embodiment, first, the SOC value input at each time is a specific value, the frequency deviation input at each time is a specific value, and the SOC value SOC at time t _t Fuzzification processing is carried out, and the SOC at the moment t is determined _t Possibility mu belonging to three fuzzy sets L, M, H _L (SOC _t )、μ _M (SOC _t )、μ _H (SOC _t ) (first membership degree) frequency deviation Δf for time t _t Performing blurring processing to determine time Δf at t _t Probability μ of belonging to seven fuzzy sets NL, NM, NS, O, PS, PM, PL _NL (Δf _t )、μ _NM (Δf _t )、μ _NS (Δf _t )、μ _O (Δf _t )、μ _NM (Δf _t )、μ _PM (Δf _t )、μ _PL (Δf _t ) (second membership degree), then, combining table 1 and a third preset membership degree function, obtaining a compensation membership degree function at time t as follows:

wherein, as shown in Table 1, the first degree of membership (μ _L (SOC _t )、μ _M (SOC _t )、μ _H (SOC _t ) A second degree of membership (mu) _NL (Δf _t )、μ _NM (Δf _t )、μ _NS (Δf _t )、μ _O (Δf _t )、μ _NM (Δf _t )、μ _PM (Δf _t )、μ _PL (Δf _t ) And a third preset membership function (mu) _VS (K _comp )、μ _S (K _comp )、μ _M (K _comp )、μ _L (K _comp )、μ _VL (K _comp ) 21 combinations, finally, +.>Solving the compensation membership function by a gravity center method to obtain a compensation coefficient at the moment t, wherein K _comp,t And is the compensation coefficient at the time t.

According to the embodiment, under the condition that the frequency change rate is larger than zero, namely in the inertia response stage, virtual inertia control is taken as a main component, droop control is taken as an auxiliary component, and in the primary frequency modulation stage, droop control is adopted, so that the problem that the frequency adjustment mode of the traditional wind-solar-energy-storage combined power generation system does not consider the main component and the secondary component of different virtual inertia control or droop control in different frequency modulation stages is solved.

Example 1

The frequency modulation method of the wind-solar combined power generation system in fig. 1 by applying the wind-solar combined power generation system is characterized in that a load L1 is set to generate 15% (18.75 MW) sudden load increase at the moment t=1s, a synchronous machine is adopted to perform frequency modulation, a synchronous machine and virtual inertia control are adopted to perform frequency modulation, the synchronous machine and droop control are adopted to perform frequency modulation, the synchronous machine and the virtual inertia control are adopted to perform frequency modulation, the synchronous machine and droop control are combined, the synchronous machine and the frequency modulation method of the wind-solar combined power generation system are simulated, as shown in fig. 10, the frequency characteristic of the wind-solar combined power generation system can be improved more effectively than that of a single control strategy or a simple combination of the wind-solar combined power generation system, namely, virtual inertia control is led to be dominant in an inertia response stage, the frequency dropping speed is slowed down, the lowest frequency point is promoted, the frequency is led to be recovered more rapidly in a primary frequency modulation stage, and steady-state frequency deviation is reduced, as shown in fig. 11, the frequency modulation method of the wind-solar combined power generation system is adopted _I Compared with the initial value K _I0 Is a droop control coefficient K _D Compared with the initial value K _D0 Is a variation of (c).

As can be seen from fig. 12 (a), fig. 12 (b), fig. c, and fig. d, the SOC values of the energy storage systems are compared When the frequency deviation is large and serious, the compensation coefficient K _comp The energy storage system is larger, so that the release of the electric energy of the energy storage system is accelerated, the energy storage SOC is maintained in a healthy state, the frequency improvement is accelerated, and when the frequency recovery is better, the compensation coefficient K is compensated _comp The frequency modulation method of the wind-solar-energy-storage combined power generation system can be gradually smaller, and the active power output of the energy storage system is slowly reduced along with time so that the energy storage system is not excessively discharged, and therefore the function of self-adaptively tracking the SOC value and adjusting the active power output of the energy storage system by the frequency deviation delta f is better achieved.

It should be noted that the steps illustrated in the flowcharts of the figures may be performed in a computer system such as a set of computer executable instructions, and that although a logical order is illustrated in the flowcharts, in some cases the steps illustrated or described may be performed in an order other than that illustrated herein.

The embodiment of the application also provides a frequency modulation device of the wind-light-storage combined power generation system, and the frequency modulation device of the wind-light-storage combined power generation system can be used for executing the frequency modulation method for the wind-light-storage combined power generation system. The device is used for realizing the above embodiments and preferred embodiments, and is not described in detail. As used below, the term "module" may be a combination of software and/or hardware that implements a predetermined function. While the means described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware, is also possible and contemplated.

The frequency modulation device of the wind-solar-energy-storage combined power generation system provided by the embodiment of the application is introduced as follows.

Fig. 13 is a schematic diagram of a frequency modulation device of a wind-solar-energy-storage combined power generation system according to an embodiment of the application. As shown in fig. 13, the apparatus includes:

an acquisition unit 10, configured to acquire a frequency change rate of the ac bus when active power disturbance occurs in the ac bus;

Specifically, the frequency of the ac bus is the frequency of the power grid.

A first control unit 20, configured to control the operation of the energy storage system by using a first control strategy when the frequency change rate is greater than zero, until the frequency change rate is equal to zero, where the first control strategy is to gradually decrease a virtual inertia control coefficient in a first power function and gradually increase a droop control coefficient in the first power function, and the first power function is a functional relationship between an active power output of the energy storage system and a frequency deviation of the frequency change rate and the ac bus;

wherein H is equivalent inertial time constant of the synchronous machine set, D is equivalent damping of the synchronous machine set, R is droop coefficient of the speed regulator, and delta P is calculated by the method _L K is active power disturbance _I K is a virtual inertial control coefficient _D For primary frequency modulation droop control factor, ΔF ^I (s) is adoptedFrequency deviation, Δf after virtual inertial control ^D (s) is the frequency deviation after primary frequency modulation droop control, and the maximum value and the steady-state frequency deviation of the frequency change rates of the two control modes are obtained after the Laplace initial value and the final value theorem are as follows:

virtual inertial control:

primary frequency modulation droop control:

The first control unit is used for, in the case that the frequency change rate is greater than zero, according to the followingControlling the operation of the energy storage system, wherein P _bess-fina For the active force of the energy storage system, df/dt is the frequency change rate, Δf is the frequency deviation, K _I0 For presetting virtual inertia control coefficient, K _D0 To preset the sagging control coefficient, k ₀ For a first preset value, m ₀ Is a second preset value, K _comp The compensation coefficient is determined by the frequency deviation and the SOC value of the energy storage system. />

In this embodiment, the first power function is For the virtual inertial control coefficient in the first power function,/- >In order to solve the problems that in the prior art, the energy storage participation frequency adjustment mode in the wind-solar-energy-storage combined power generation system is mainly based on the protection of the SOC of the energy storage system, and is not related to the actual frequency deterioration degree, a compensation coefficient is introduced, the compensation coefficient is formed by frequency deviation and the SOC value of the energy storage system, the frequency deviation reflects the actual frequency deterioration degree, namely, the active output of the energy storage system still depends on the compensation coefficient in the inertia response stage, so that the active output of the energy storage system is adjusted according to the frequency deterioration degree under the condition of maintaining the health state, and the problem that in the prior art, the energy storage participation frequency adjustment mode in the wind-solar-energy-storage combined power generation system is mainly based on the protection of the SOC of the energy storage system is mainly based on the single consideration.

In particular, the method comprises the steps of, Wherein k is ₀ The value is generally 0.5, so as to ensure that droop control is dominant at the moment of switching from the inertia response phase to the primary frequency modulation phase, m ₀ Should be positive, m ₀ Depending on the total inertia and the maximum possible load fluctuation of the wind-solar-energy-storage combined power generation system.

And a second control unit 30, configured to control the operation of the energy storage system by using a second control strategy when the frequency change rate is equal to zero, until the frequency change rate is within a preset frequency change rate range, where the second control strategy is that a droop control coefficient in a second power function is determined by the frequency deviation, and the second power function is a functional relationship between the frequency deviation and an active power of the energy storage system.

The second control unit is used for, in the case that the frequency change rate is equal to zero, according to Controlling the operation of the energy storage system, wherein P _bess-fina For the active force of the energy storage system, df/dt is the frequency change rate, Δf is the frequency deviation, Δf _max K is the maximum value of the frequency deviation _I0 For presetting virtual inertia control coefficient, K _D0 To preset the sagging control coefficient, k ₁ For a third preset value, m ₁ For a fourth preset value, K _comp The compensation coefficient is determined by the frequency deviation and the SOC value of the energy storage system.

In this embodiment, the second power function is Is a droop control coefficient in the second power function, so that the virtual inertial control is blocked, i.e. the virtual inertial control coefficient becomes zero, in the primary frequency modulation stage, and the droop control coefficient is set by the absolute value of the frequency deviation, i.e. the droop control is performed in the primary frequency modulation stageThe method has the advantages that the frequency of an alternating current bus is recovered more quickly, steady-state frequency deviation is reduced, in order to solve the problems that in the prior art, the energy storage participation frequency adjustment mode in the wind-solar-energy-storage combined power generation system is mainly the protection of the SOC of the energy storage system and is not related to the actual frequency deterioration degree, a compensation coefficient is introduced, the compensation coefficient is formed by the frequency deviation and the SOC value of the energy storage system, the frequency deviation reflects the actual frequency deterioration degree, namely, the active force of the energy storage system also depends on the compensation coefficient in a primary frequency modulation stage, so that the active force of the energy storage system is adjusted according to the frequency deterioration degree under the condition of maintaining a healthy state, and the problem that in the prior art, the energy storage participation frequency adjustment mode in the wind-solar-energy-storage combined power generation system is mainly the protection of the SOC of the energy storage system is singly considered is solved.

In an alternative, the apparatus further includes:

and the processing unit is used for inputting the frequency deviation and the SOC value into a fuzzy logic controller to obtain the compensation coefficient.

In this embodiment, in order to solve the problem that in the prior art, the protection of the SOC of the energy storage system is singly considered, the protection is not related to the actual frequency degradation degree, and a specific mathematical function is mostly adopted, the functions are various, the advantages and disadvantages of which are difficult to evaluate and the applicability of which are to be evaluated, the application adopts the frequency deviation and the SOC value to jointly determine the compensation coefficient, thereby solving the problem that in the prior art, the protection of the SOC of the energy storage system is singly considered, the protection is not related to the actual frequency degradation degree, and the application adopts the fuzzy logic controller to monitor the SOC value and the frequency deviation of the energy storage system in real time,determining the compensation coefficient in real time, further promoting the improvement of the frequency of the alternating current bus under the condition that the energy storage system is in a safe and healthy state as much as possible, compared with a specific mathematical function, the fuzzy logic controller has stronger fault tolerance capability on parameter selection, as shown in fig. 6, and inputs (SOC value and frequency deviation delta f) -outputs (compensation coefficient K) _comp ) A relation diagram, according to which the fuzzy logic controller determines the compensation coefficient K based on the SOC value and the frequency deviation Deltaf _comp 。

specifically, the SOC value has a value range of [0,1]The SOC value is recorded as three fuzzy sets: { Low, medium, high }, abbreviated as { L, M, H }, the first preset membership function isC in the first preset membership function corresponding to each fuzzy set ₁ And c ₂ Is different in value, mu as shown in FIG. 7 _L (SOC) is the curve of the first preset membership function corresponding to the fuzzy set L, mu _M (SOC) is a curve of a first preset membership function of the fuzzy set M, μ _H And (SOC) is a first preset membership function curve corresponding to the fuzzy set H, and the possibility that the SOC value belongs to each fuzzy set L, M, H is calculated by using the first preset membership function (joint Gaussian membership function) corresponding to each fuzzy set, so as to obtain the first membership corresponding to each fuzzy set, namely, the possibility that the SOC value is subjected to fuzzification processing to calculate the SOC value at each sampling moment belongs to three fuzzy sets L, M, H.

Table 1 control rule table of fuzzy logic controller

In the present embodiment, first, the SOC value input at each time is a specific value, the frequency deviation input at each time is a specific value, and the SOC value SOC at time t _t Fuzzification processing is carried out, and the SOC at the moment t is determined _t Possibility mu belonging to three fuzzy sets L, M, H _L (SOC _t )、μ _M (SOC _t )、μ _H (SOC _t ) (first membership degree) frequency deviation Δf for time t _t Performing blurring processing to determine time Δf at t _t Belonging to the seven fuzzy sets NL, NM,possibility of NS, O, PS, PM, PL. Mu. _NL (Δf _t )、μ _NM (Δf _t )、μ _NS (Δf _t )、μ _O (Δf _t )、μ _NM (Δf _t )、μ _PM (Δf _t )、μ _PL (Δf _t ) (second membership degree), then, combining table 1 and a third preset membership degree function, obtaining a compensation membership degree function at time t as follows:/>

According to the embodiment, under the condition that the frequency change rate is larger than zero, namely in the inertia response stage, virtual inertia control is taken as a main component, droop control is taken as an auxiliary component, and in the primary frequency modulation stage, droop control is adopted, so that the problem that the frequency adjustment mode of the traditional wind-solar-energy-storage combined power generation system does not consider the main component and the secondary component of the virtual inertia control or the droop control in different frequency modulation stages is solved.

The frequency modulation device of the wind-solar combined power generation system comprises a processor and a memory, wherein the acquisition unit, the first control unit, the second control unit and the like are stored in the memory as program units, and the processor executes the program units stored in the memory to realize corresponding functions. The modules are all located in the same processor; alternatively, the above modules may be located in different processors in any combination.

The processor includes a kernel, and the kernel fetches the corresponding program unit from the memory. The frequency adjustment mode of the existing wind-solar-energy-storage combined power generation system does not consider the problem that different virtual inertial control or sagging control is divided into primary and secondary in different frequency adjustment stages by adjusting the parameters of the core.

The memory may include volatile memory, random Access Memory (RAM), and/or nonvolatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM), among other forms in computer readable media, the memory including at least one memory chip.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises an element.

From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

1) The frequency modulation method of the wind-solar combined power generation system is characterized in that virtual inertial control is used as a main component and droop control is used as an auxiliary component in an inertial response stage under the condition that the frequency change rate is larger than zero, and droop control is used in a primary frequency modulation stage, so that the problem that the frequency adjustment mode of the traditional wind-solar combined power generation system does not consider the main component and the auxiliary component of the virtual inertial control or the droop control in different frequency modulation stages is solved.

2) The frequency modulation device of the wind-solar combined power generation system takes virtual inertial control as a main component and drooping control as an auxiliary component in an inertial response stage under the condition that the frequency change rate is larger than zero, and adopts drooping control in a primary frequency modulation stage, so that the problem that the frequency adjustment mode of the traditional wind-solar combined power generation system does not consider the main component and the minor component of the virtual inertial control or drooping control in different frequency modulation stages is solved.

The above description is only of the preferred embodiments of the present application and is not intended to limit the present application, but various modifications and variations can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. The utility model provides a frequency modulation method of wind-light-storage combined power generation system, its characterized in that, wind-light-storage combined power generation system includes wind power generation system, photovoltaic power generation system, energy storage system and ac bus, wind power generation system, photovoltaic power generation system with energy storage system respectively with ac bus electricity is connected, ac bus is connected with the electric wire netting electricity, the method includes:

under the condition that active power disturbance occurs to the alternating current bus, acquiring the frequency change rate of the alternating current bus;

when the frequency change rate is greater than zero, a first control strategy is adopted to control the energy storage system to operate until the frequency change rate is equal to zero, wherein the first control strategy is to gradually reduce a virtual inertia control coefficient in a first power function and gradually increase a droop control coefficient in the first power function, and the first power function is a functional relation between the active force of the energy storage system, the frequency change rate and the frequency deviation of the alternating current bus;

and under the condition that the frequency change rate is equal to zero, controlling the energy storage system to operate by adopting a second control strategy until the frequency change rate is within a preset frequency change rate range, wherein the second control strategy is that a droop control coefficient in a second power function is determined by the frequency deviation, and the second power function is a functional relation between the frequency deviation and the active power of the energy storage system.

2. The method of claim 1, wherein, in the event that the rate of frequency change is greater than zero, controlling operation of the energy storage system using a first control strategy until the rate of frequency change is equal to zero comprises:

in the case that the rate of change of the frequency is greater than zero, according to P _bess-fina ＝K _comp ×P _bess-init ，Controlling the operation of the energy storage system, wherein P _bess-fina For the active force of the energy storage system, df/dt is the frequency change rate, Δf is the frequency deviation, K _I0 For presetting virtual inertia control coefficient, K _D0 To preset the sagging control coefficient, k ₀ For a first preset value, m ₀ Is a second preset value, K _comp For a compensation coefficient, the compensation coefficient is determined by the frequency deviation and an SOC value of the energy storage system.

3. The method of claim 1, wherein, in the event that the rate of frequency change is equal to zero, controlling operation of the energy storage system using a second control strategy until the rate of frequency change is within a predetermined range of rates of frequency change comprises:

in the case where the rate of change of the frequency is equal to zero, according to P _bess-fina ＝K _comp ×P _bess-init ，Controlling the operation of the energy storage system, wherein P _bess-fina For the active force of the energy storage system, df/dt is the frequency change The rate, Δf is the frequency deviation, Δf _max K is the maximum value of the frequency deviation _I0 For presetting virtual inertia control coefficient, K _D0 To preset the sagging control coefficient, k ₁ For a third preset value, m ₁ For a fourth preset value, K _comp For a compensation coefficient, the compensation coefficient is determined by the frequency deviation and an SOC value of the energy storage system.

4. A method according to claim 2 or 3, characterized in that the method comprises:

5. The method of claim 4, wherein the operation of the fuzzy logic controller comprises:

determining a compensation membership function based on the first membership, the second membership, a third preset membership function and a control rule of the fuzzy logic controller, wherein the compensation membership function is a function with independent variables as the compensation coefficient;

6. The method of claim 5, wherein the control rule of the fuzzy logic controller is a mapping table:

the mapping relation table characterizes the mapping relation between the frequency deviation and the SOC value and the compensation coefficient, when the frequency deviation is a negative value and the SOC value is fixed, the absolute value of the frequency deviation is larger, the compensation coefficient is larger, and when the frequency deviation is a negative value and the frequency deviation is fixed, the SOC value is larger, and the compensation coefficient is larger;

the larger the frequency deviation is, the larger the compensation coefficient is, when the frequency deviation is a positive value and the SOC value is fixed, and the smaller the SOC value is, the larger the compensation coefficient is, when the frequency deviation is a positive value and the frequency deviation is fixed.

7. The utility model provides a wind-solar energy storage cogeneration system's frequency modulation device which characterized in that, wind-solar energy storage cogeneration system includes wind power generation system, photovoltaic power generation system and energy storage system, wind power generation system photovoltaic power generation system with energy storage system is connected with the alternating current busbar electricity respectively, alternating current busbar is connected with the electric wire netting electricity, the device includes:

The acquisition unit is used for acquiring the frequency change rate of the alternating current bus under the condition that the alternating current bus is subjected to active power disturbance;

the first control unit is used for controlling the energy storage system to operate by adopting a first control strategy under the condition that the frequency change rate is larger than zero until the frequency change rate is equal to zero, wherein the first control strategy is to gradually reduce a virtual inertia control coefficient in a first power function and gradually increase a sagging control coefficient in the first power function, and the first power function is a functional relation between the active output of the energy storage system and the frequency change rate and the frequency deviation of the alternating current bus;

and the second control unit is used for controlling the energy storage system to operate by adopting a second control strategy under the condition that the frequency change rate is equal to zero until the frequency of the wind-solar-storage combined power generation system is kept stable, wherein the second control strategy is that a sagging control coefficient in a second power function is determined by the frequency deviation, and the second power function is a functional relation between the frequency deviation and the active power output of the energy storage system.

8. A computer-readable storage medium, characterized in that the computer-readable storage medium comprises a stored program, wherein the program, when run, controls a device in which the computer-readable storage medium is located to execute the frequency control method of the wind-solar energy-storage cogeneration system according to any one of claims 1 to 6.

9. A processor, characterized in that the processor is configured to run a program, wherein the program when run performs the frequency control method of the wind-solar-energy-storage combined power generation system according to any one of claims 1 to 6.

10. An electronic device, comprising: one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs comprising a frequency control method for performing the wind-solar cogeneration system of any one of claims 1 to 6.