Wind storage combined frequency modulation control method and system for new energy high-proportion electric power system

Abstract

The invention discloses a wind storage combined frequency modulation control method and system for a new energy high-proportion power system, and relates to the field of power system regulation and control, and the method comprises the steps: judging the range of the frequency f of a detected system based on the steady-state frequency response of the system when the frequency of the power system changes, and activating the energy storage frequency response if the f is in a preset range; if the system frequency deviation exceeds the range, wind turbine generator frequency modulation is started, the wind speed zone of fan operation is judged, and the wind speed zone is divided into different operation areas of a fan according to the wind speed; a mode of jointly adjusting energy storage and a wind turbine generator is adopted, the wind turbine generator adjusts the system frequency to be within a preset range, then energy storage frequency adjustment is started, and the power system frequency recovers to the normal level. According to the method, the influence of different operation modes and wind speed disturbance of the fan during wind storage combined frequency modulation is considered in a centralized manner, and the fan enters the operation state in different operation modes in different wind speed operation areas, so that the research result of wind power participating in system frequency regulation better fits the reality.

Description

Technical Field

[0001] The present invention relates to the field of power system regulation and control, in particular to a wind-storage combined frequency modulation control method and system for a power system with a high proportion of new energy. Background Art

[0002] The power electronic interface causes the new energy grid connection to have no inertia or weak inertia. Therefore, the continuous increase in new energy power generation will lead to a continuous decline in the grid inertia, which will also have an adverse impact on the frequency of the power system. The large-scale grid connection of wind and photovoltaic power generation also reduces the resistance of the power system to extreme weather such as typhoons and heavy rains. As a resource with fast response ability, energy storage can provide inertia support for the power system. Its installation location and capacity configuration are flexible, and it has strong customization ability, and can adapt to different frequency modulation requirements through the control strategy and parameter optimization of the interface. In addition, when the high-proportion new energy power generation system encounters extreme weather impacts, energy storage can assist the traditional generator sets to output power to achieve power restoration. Its fast, accurate, and controllable frequency modulation ability is the advantage of energy storage compared with traditional generator sets. At the same time, energy storage can also suppress the output power fluctuations of wind and photovoltaic power generation, thereby improving the power system's ability to absorb new energy power generation. When large-scale wind power is connected to the grid, the wind power itself should also have primary frequency modulation ability.

[0003] Disadvantages of the Existing Technology

[0004] 1. There is no mechanism analysis on the combined frequency modulation of wind power and energy storage in a large-scale new energy system

[0005] When a high proportion of new energy is connected to the grid, the power electronic interface causes the grid inertia and the system frequency regulation performance to continuously decrease. As the capacity of traditional units is continuously replaced by new energy units, relying solely on traditional units for frequency regulation can no longer meet the requirements of continuous new energy grid connection. According to the fast frequency modulation characteristics of energy storage, energy storage is added to the system for auxiliary frequency modulation. Since large-scale wind power grid connection requires wind turbines to have primary frequency modulation ability, the primary frequency modulation of wind power combined with the frequency inertia response and primary frequency modulation effect of energy storage can jointly provide frequency support for the power system with a high proportion of new energy. Mechanism research on the above frequency modulation method obtains the influence of wind and energy storage on the system frequency index respectively.

[0006] 2. The influence of different operating modes of wind turbines and wind speed disturbances during wind-storage combined frequency modulation is not considered

[0007] The active power regulation ability of a wind farm is greatly affected by wind speed. The single control mode of wind turbines cannot effectively support large frequency disturbances. By collecting wind speed and determining the operating area of wind turbines according to the wind speed, different operating modes can be adopted in different operating areas, thereby changing the operating state of wind turbines, avoiding the single operating mode of wind turbines, and improving the ability of wind power to regulate the system frequency. Wind speed disturbances also have a certain impact on the frequency of the power system and cannot be ignored. Classification can also be carried out according to different operating areas. Energy storage should participate in the wind power frequency regulation support in high, medium, and low wind speed areas, not limited to a single operating area, which can more efficiently play the role of energy storage in frequency regulation support, be more in line with the actual situation, and also improve the flexibility of coordination and cooperation between wind power and energy storage. Summary of the Invention

[0008] In view of the above problems, the present invention is proposed.

[0009] Therefore, the problems to be solved by the present invention are as follows: The prior art does not conduct a mechanism analysis on the combined frequency regulation of wind power and energy storage in a large-scale new energy system, and does not consider the influence of different operating modes of wind turbines and wind speed disturbances during combined wind-storage frequency regulation.

[0010] To solve the above technical problems, the present invention provides the following technical solution: A method for controlling the combined frequency regulation of wind power and energy storage in a power system with a high proportion of new energy, which includes, when the frequency of the power system changes, based on the steady-state frequency response of the system, determining the range in which the measured system frequency f is located. If f is within a preset range, the energy storage frequency response is activated; if the system frequency deviation exceeds the range, the wind turbine is started for frequency regulation, and the wind speed area in which the wind turbine operates is judged. The wind speed area divides different operating areas of the wind turbine according to the wind speed, and different operating areas correspond to different wind speed disturbances. The energy storage and the wind turbine are used in a combined regulation manner. Based on the transfer function of different wind speed areas, the wind turbine adjusts the system frequency to within the preset range, and then the energy storage frequency regulation is started to restore the power system frequency to the normal level.

[0011] As a preferred solution of the method for controlling the combined frequency regulation of wind power and energy storage in a power system with a high proportion of new energy according to the present invention, among them: The situation where f is within the preset range includes 49.95Hz < f < 50.05Hz; the wind speed areas include high wind speed areas, medium wind speed areas, and low wind speed areas; the determination range of the high wind speed area is that the wind speed v is greater than or equal to 12m / s, and the determination range of the low wind speed area is that the wind speed v is less than 9m / s. When v ∈ [9, 12)m / s, it is determined as the medium wind speed area.

[0012] As a preferred solution of the wind-storage combined frequency modulation control method for a power system with a high proportion of new energy in the present invention, wherein: adjusting the system frequency to a preset range by the wind turbine includes that when the wind turbine operates in a low wind speed area, the wind turbine adopts the maximum power point MPPT operation mode, and in the frequency response of the improved system SFR of wind-storage combined frequency modulation, G w (s)=G l (s), G v (s)=G vl (s); when the wind turbine operates in a medium wind speed area, the wind turbine adopts a coordinated control mode of virtual inertia and over-speed load shedding, and in the frequency response of the improved system SFR of wind-storage combined frequency modulation, G w (s)=G m (s), G v (s)=G vm (s); when the wind turbine operates in a high wind speed area, the wind turbine adopts a coordinated control mode of virtual inertia and pitch angle, and in the frequency response of the improved system SFR of wind-storage combined frequency modulation, G w (s)=G h (s), G v (s)=G vh (s); wherein, G w (s) represents the transfer function of power change and system frequency deviation, G v (s) represents the transfer function of the power change of the wind turbine caused by wind speed disturbance, G l (s) represents the transfer function of power change and system frequency deviation in the low wind speed area, G vl (s) represents the transfer function of the power change of the wind turbine caused by wind speed disturbance in the low wind speed area, G m (s) represents the transfer function of power change and system frequency deviation in the medium wind speed area, G vm (s) represents the transfer function of the power change of the wind turbine caused by wind speed disturbance in the medium wind speed area, G h (s) represents the transfer function of power change and system frequency deviation in the high wind speed area, G vh (s) represents the transfer function of the power change of the wind turbine caused by wind speed disturbance in the high wind speed area.

[0013] As a preferred solution of the wind-storage combined frequency modulation control method for a power system with a high proportion of new energy in the present invention, wherein: the improved system SFR of wind-storage combined frequency modulation is a sub-synchronous frequency response model for frequency modulation of a power grid with new energy participated by energy storage; the SFR includes recalculating the inertia of the power system based on the new energy grid connection amount, replacing the conventional synchronous generator with a wind turbine and photovoltaic power generation of the same capacity, and obtaining the transfer function G of power change and system frequency deviation by linearizing the frequency control link equation w(s) and the transfer function G of the wind turbine power change caused by wind speed disturbance v (s).

[0014] As a preferred solution of the wind-storage combined frequency modulation control method for a power system with a high proportion of new energy described in the present invention, wherein: when the wind turbine operates in the low wind speed area, the wind turbine adopts the maximum power point MPPT operation mode, including that in the low wind speed area, the wind turbine cannot provide inertia support for the system and does not respond to the frequency dynamics of the power grid. Therefore, the transfer function G of the power change in the low wind speed area and the system frequency deviation l (s) and the transfer function G of the wind turbine power change caused by the wind speed disturbance in the low wind speed area vl (s) are expressed as

[0015] G l (s) = 0

[0016]

[0017] Among them, G vl (s) reflects the coordinated operation mode of the virtual inertia and over-speed load shedding of the wind turbine in the low wind speed area; s is a complex variable, and g l , q l are the wind speed disturbance coefficients in the low wind speed area, and the formula is expressed as

[0018]

[0019] Among them, ω is the rotor speed of the wind turbine, v is the wind speed, H t is the inertia constant of the wind turbine, k p is the proportionality factor, ρ is the air density, C p is the wind energy utilization coefficient, C p,max is the maximum value of the wind energy utilization coefficient, P base is the rated power, C Pref is the reference value of the wind energy utilization coefficient, k c is the partial derivative value of C p with respect to λ, λ is the tip speed ratio, and λ ref is the reference value of the tip speed ratio.

[0020] As a preferred solution of the wind-storage combined frequency modulation control method for a power system with a high proportion of new energy described in the present invention, wherein: when the wind turbine operates in the medium wind speed area, the coordinated control mode of the wind turbine adopting virtual inertia and over-speed load shedding includes that in the medium wind speed area, the wind turbine has sufficient reserve capacity to participate in primary frequency modulation. An integrated frequency control strategy of virtual inertia control and over-speed load shedding control is adopted. Through virtual inertia control, the wind turbine responds to the power grid frequency change and improves the system inertia. Through over-speed load shedding control, the wind turbine can obtain a certain amount of reserve power; the transfer function G of the power change in the medium wind speed area and the system frequency deviationm (s) and the transfer function G of the wind turbine power change caused by the wind speed disturbance in the medium wind speed area vm (s) is expressed as

[0021]

[0022] Among them, G vm (s) reflects the coordinated operation mode of the virtual inertia and over-speed load shedding of the wind turbine in the medium wind speed area; a m , b m , c m are the wind power frequency modulation coefficients in the medium wind speed area, g m , q m are the wind speed disturbance coefficients in the medium wind speed area, and the formula is expressed as

[0023]

[0024] Among them, d is the load shedding rate, ω d is the rotor speed during load shedding power operation, ω m is the rotor speed during maximum power operation, k v and R v are the virtual inertia control parameters.

[0025] As a preferred solution of the wind storage combined frequency modulation control method for a power system with a high proportion of new energy described in the present invention, among them: when the wind turbine operates in the high wind speed area, the coordinated control method of the virtual inertia and pitch angle of the wind turbine includes that in the high wind speed area, the rotor speed of the wind turbine reaches the maximum limit, and load shedding operation cannot be carried out through over-speed control. The output power of the wind turbine is adjusted through the pitch angle control method to participate in system frequency support; the transfer function G of the power change in the high wind speed area and the system frequency deviation h (s) and the transfer function G of the wind turbine power change caused by the wind speed disturbance in the high wind speed area vh (s) is expressed as

[0026]

[0027] Among them, G vh (s) reflects the coordinated operation mode of the virtual inertia and pitch angle control of the wind turbine in the high wind speed area; a h , b h , c h are the wind power frequency modulation coefficients in the high wind speed area, g h , q h are the wind speed disturbance coefficients in the high wind speed area, and the formula is expressed as

[0028]

[0029] Among them, Ktotal,h = 2k p ω 3 + k p C Pref v 3 - k p k c ωv 2 ,k β is the partial derivative value of C p with respect to β, where β is the pitch angle of the wind turbine, and k b is the frequency adjustment proportionality coefficient introduced for pitch angle control.

[0030] Another object of the present invention is to provide a wind-storage combined frequency modulation control system for a power system with a high proportion of new energy. This system adopts a method of jointly adjusting by energy storage and wind turbines. When the system frequency deviation exceeds the range, the wind turbines adjust the system frequency to the preset range, and then start the energy storage frequency adjustment to restore the power system frequency to the normal level.

[0031] To solve the above technical problems, the present invention provides the following technical solutions: A wind-storage combined frequency modulation control system for a power system with a high proportion of new energy, comprising: a frequency detection module, a working condition judgment module, and a frequency adjustment module; the frequency detection module is used to detect the frequency state of the power system. When the power system has a frequency change, based on the steady-state frequency response of the system, it judges the range where the measured system frequency f is located. If f is within the preset range, the energy storage frequency response is activated. If the system frequency deviation exceeds the range, the wind turbines are started for frequency modulation; the working condition judgment module is used to judge the wind speed area where the wind turbines operate. The wind speed area divides different operating areas of the wind turbines according to the wind speed, and different operating areas correspond to different wind speed disturbances; the frequency adjustment module adopts a method of jointly adjusting by energy storage and wind turbines. Based on the transfer function of different wind speed areas, the wind turbines adjust the system frequency to the preset range, and then start the energy storage frequency adjustment to restore the power system frequency to the normal level.

[0032] A computer device, comprising a memory and a processor, where the memory stores a computer program, and when the processor executes the computer program, it implements the steps of the above-mentioned wind-storage combined frequency modulation control method for a power system with a high proportion of new energy.

[0033] A computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the steps of the above-mentioned wind-storage combined frequency modulation control method for a power system with a high proportion of new energy.

[0034] The beneficial effects of the present invention are as follows: Based on the traditional unit frequency regulation, energy storage is added for auxiliary frequency regulation in the present invention, a mathematical model of wind-storage combined frequency regulation in a power system with a high proportion of new energy is constructed, and the influence of the proportion of new energy and energy storage frequency regulation parameters on the system regulation coefficient and frequency index is given, providing theoretical support for the current situation of new energy and energy storage participating in system frequency regulation.

[0035] The present invention comprehensively considers the influence of different operating modes of wind turbines and wind speed disturbances during wind-storage combined frequency regulation, divides the operating area of wind turbines according to the wind speed, and under different operating areas, the wind turbines adopt different operating modes to enter the operating state. In addition, the research on the influence of wind speed disturbances on the frequency of the power system is added, making the research results of wind power participating in system frequency regulation more in line with the actual situation.

[0036] Based on the feasibility study at the theoretical level, the present invention proposes a wind-storage combined frequency regulation control strategy in a power system with a high proportion of new energy. This control strategy optimizes the actual power system frequency regulation index through the frequency regulation cooperation between energy storage and wind power, and the simulation results prove the advantages of this control strategy. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for description in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0038] Figure 1 It is a control strategy diagram of energy storage coordinating wind power to participate in power grid frequency regulation for a wind-storage combined frequency regulation control method of a power system with a high proportion of new energy in Embodiment 1.

[0039] Figure 2 It is an extended SFR model diagram for a wind-storage combined frequency regulation control method of a power system with a high proportion of new energy in Embodiment 1.

[0040] Figure 3 It is a frequency curve change diagram under different proportions of traditional motor generating capacities for a wind-storage combined frequency regulation control method of a power system with a high proportion of new energy in Embodiment 1.

[0041] Figure 4 It is a frequency curve change diagram under different energy storage frequency regulation gain coefficients for a wind-storage combined frequency regulation control method of a power system with a high proportion of new energy in Embodiment 1.

[0042] Figure 5 It is a frequency curve change diagram under different energy storage charge-discharge time constants for a wind-storage combined frequency regulation control method of a power system with a high proportion of new energy in Embodiment 1.

[0043] Figure 6 It is a coordination control diagram of virtual inertia and over-speed load shedding for a wind-storage combined frequency regulation control method in a power system with a high proportion of new energy in Embodiment 2.

[0044] Figure 7 It is a coordination control diagram of virtual inertia and pitch angle for a wind-storage combined frequency regulation control method in a power system with a high proportion of new energy in Embodiment 2.

[0045] Figure 8 It is an improved IEEE 9-node system diagram for a wind-storage combined frequency regulation control method in a power system with a high proportion of new energy in Embodiment 3.

[0046] Figure 9 It is a system frequency change curve diagram when energy storage frequency regulation is added at 6 s under wind power frequency regulation for a wind-storage combined frequency regulation control method in a power system with a high proportion of new energy in Embodiment 3.

[0047] Figure 10 It is a comparison curve diagram of energy storage independent frequency regulation and wind-storage combined frequency regulation for a wind-storage combined frequency regulation control method in a power system with a high proportion of new energy in Embodiment 3.

[0048] Figure 11 It is a comparison curve diagram of primary frequency regulation of wind power under different wind power penetration rates for a wind-storage combined frequency regulation control method in a power system with a high proportion of new energy in Embodiment 3.

[0049] Figure 12 It is a comparison curve diagram of frequency regulation under different operating regions of the fan for a wind-storage combined frequency regulation control method in a power system with a high proportion of new energy in Embodiment 3

[0050] Figure 13 It is a comparison curve diagram of system frequency under different wind speed disturbances for a wind-storage combined frequency regulation control method in a power system with a high proportion of new energy in Embodiment 3.

[0051] Figure 14 It is a wind speed disturbance model diagram for a wind-storage combined frequency regulation control method in a power system with a high proportion of new energy in Embodiment 3.

[0052] Figure 15 It is a system frequency change curve diagram under the wind speed disturbance model for a wind-storage combined frequency regulation control method in a power system with a high proportion of new energy in Embodiment 3. Detailed implementation manners

[0053] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will describe the detailed implementation manners of the present invention with reference to the accompanying drawings of the specification.

[0054] In the following description, many specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention may be practiced in other ways than those specifically described herein. Those skilled in the art can make similar generalizations without departing from the spirit of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0055] Example 1. Refer to Figures 1 - 5 , which is the first embodiment of the present invention. This embodiment provides a wind storage combined frequency regulation control method for a power system with a high proportion of new energy, including, as Figure 1 shown:

[0056] Step 1: Determine whether there is a frequency change in the power system. If so, go to Step 2.

[0057] Step 2: Based on the steady-state frequency response of the system, determine the range in which the measured system frequency f lies. If 49.95 Hz < f < 50.05 Hz, activate the energy storage frequency response. If the system frequency deviation exceeds the range, go to Step 3.

[0058] Step 3: Start the wind turbine for frequency regulation. Determine the high, medium, and low wind speed regions in which the wind turbine operates. Divide the different operating regions of the wind turbine according to the wind speed, and different operating regions correspond to different wind speed disturbances.

[0059] Step 4: The energy storage and the wind turbine act together. First, the wind turbine adjusts the system frequency to within the range of 49.95 Hz < f < 50.05 Hz, and then activates the energy storage frequency regulation to restore the power system frequency to the normal level.

[0060] Furthermore, the power characteristics of a wind farm are greatly affected by wind speed changes. A single control mode cannot provide good support for large frequency disturbances. The present invention divides different operating regions according to the characteristics of the wind speed and proposes a method for the wind turbine to change its operating mode according to different operating regions. Specifically, the process for selecting the operating region and wind speed disturbance of the wind turbine in Step 3 is as follows:

[0061] Analyze the measured wind speed v. The determination range for the high wind speed region is that the wind speed v is greater than or equal to 12 m / s, and the determination range for the low wind speed region is that the wind speed v is less than 9 m / s. When v ∈ [9, 12) m / s, it is determined as the medium wind speed region.

[0062] Determine different control modes according to the wind speed region where the wind turbine is located, specifically as follows:

[0063] When the wind turbine operates in the low wind speed region, the wind turbine adopts the maximum power point MPPT operation mode. In the improved system SFR frequency response of the wind storage combined frequency regulation, G w (s) = G l (s), G v (s) = G vl(s).

[0064] When the wind turbine operates in the medium wind speed region, the wind power generation unit adopts a coordinated control method of virtual inertia and overspeed load shedding. In the improved system SFR frequency response of wind-storage combined frequency modulation, G w (s) = G m (s), G v (s) = G vm (s).

[0065] When the wind turbine operates in the high wind speed region, the wind power generation unit adopts a coordinated control method of virtual inertia and pitch angle. In the improved system SFR frequency response of wind-storage combined frequency modulation, G w (s) = G h (s), G v (s) = G vh (s).

[0066] Among them, G w (s) represents the transfer function of power change and system frequency deviation, G v (s) represents the transfer function of the wind turbine power change caused by wind speed disturbance, G l (s) represents the transfer function of power change and system frequency deviation in the low wind speed region, G vl (s) represents the transfer function of the wind turbine power change caused by wind speed disturbance in the low wind speed region, G m (s) represents the transfer function of power change and system frequency deviation in the medium wind speed region G vm (s) represents the transfer function of the wind turbine power change caused by wind speed disturbance in the medium wind speed region, G h (s) represents the transfer function of power change and system frequency deviation in the high wind speed region, G vh (s) represents the transfer function of the wind turbine power change caused by wind speed disturbance in the high wind speed region.

[0067] The improved system SFR of wind-storage combined frequency modulation is a sub-synchronous frequency response model for frequency modulation of a power grid with new energy participated by energy storage. It recalculates the inertia of the power system based on the new energy grid connection volume, replaces the conventional synchronous generator with a wind power generation unit and photovoltaic power generation of the same capacity, and obtains the transfer function G w (s) of power change and system frequency deviation and the transfer function G v (s) of the wind turbine power change caused by wind speed disturbance through linearizing the frequency control link equation. The SFR model of energy storage participating in the frequency modulation of a power grid with new energy specifically includes:

[0068] The stability of the power grid frequency is related to the balance of real-time active power. From the time scale, the frequency dynamics can be divided into three stages, including inertial response, primary frequency response, and secondary frequency response. Energy storage provides millisecond-level power output to optimize the extreme frequency of the frequency response, thereby participating in the inertial response of the power system and also being able to participate in the primary frequency regulation response of the system by optimizing the quasi-steady state frequency. The following analyzes the specific mechanism in detail.

[0069] The traditional SFR model is relatively commonly used. However, with the continuous replacement of conventional synchronous generator sets by new energy power generation, the inertia of the traditional power system is continuously decreasing. Therefore, it is necessary to recalculate the system inertia as follows:

[0070]

[0071] where H is the equivalent inertia of the power system, is the apparent power of the generator, and H i and S G,i are the inertia time constant and rated capacity of generator i, respectively, and n is the total number of conventional generators.

[0072] Assume that the conventional synchronous generators m1 and m2 are replaced by wind turbine generators and photovoltaic power generation of the same capacity, respectively. Then

[0073]

[0074] Let:

[0075]

[0076] Since wind and light have no inertia or weak inertia, the system inertia time constant changes to

[0077]

[0078] where S W is the total power generation capacity of the wind turbines, S P is the total power generation capacity of the photovoltaic power generation, and are the inertia constants of the traditional synchronous generators m1 and m2, respectively, and d W , d P , d G are the power generation capacity ratios of wind, light, and traditional motors, respectively, and d G +d W +d P =1.

[0079] Energy storage is a high-quality frequency regulation resource with fast response and adjustable parameters. In a power system with a low inertia level, it can provide frequency support to the power grid by injecting a large amount of active power in a short time. Its control methods have evolved from the initial droop control and virtual inertia control to coordinated control of multiple strategies to participate in frequency regulation. Ignoring the specific form of energy storage, the energy storage power supply is simply equivalent to a first-order inertia link with a time constant of T B multiplied by the control gain K B , and an active power limiting link is added.

[0080] The first-order inertia link of energy storage is used to describe the delay of the power supply, and the gain is used to simulate the relationship between the system frequency deviation Δf(s) and the change in the output of the energy storage power supply ΔP B (s). Therefore, the frequency regulation response of energy storage can be written as:

[0081]

[0082] where s is a complex variable; in addition, the high-penetration wind power and photovoltaic power generation connected to the grid require that wind turbines and photovoltaics have the ability to regulate frequency. An extended SFR model including wind, light, and energy storage frequency regulation is established as Figure 2 shown; adding wind speed disturbance to make the model more accurate. When the wind turbine and photovoltaic do not participate in frequency regulation, G w (s) = 0, G p (s) = 0, G p (s) is the transfer function of the power change of photovoltaic power generation and the system frequency deviation.

[0083] By linearizing the frequency control link equation, the wind power generation frequency response model can be described as

[0084]

[0085] where a, b, and c are wind power frequency regulation coefficients, and g and q are wind speed disturbance coefficients, which are related to the low, medium, and high wind speed operation regions of the wind turbine, and will be described in detail later.

[0086] Taking the step function as the load disturbance ΔP L (s) and the wind speed disturbance Δv(s), the formula is expressed as

[0087]

[0088] where P step is the per-unit value of the sudden change in load power, and Δv is the sudden change in wind speed.

[0089] Making an approximation to the system frequency deviation response: T B ≈T G , making the photovoltaic power generation operate in the maximum power point tracking mode, that is, not participating in grid frequency regulation, T Gis the time constant of the governor. According to Figure 2 the frequency response model of L the system frequency deviation response Δf(s) can be obtained, including the load power disturbance frequency response Δf v (s) and the wind speed disturbance frequency response Δf

[0090]

[0091] Among them,

[0092]

[0093] where D is the damping coefficient of the system, R is the droop coefficient of the governor, K is the system unit regulation power coefficient of new energy power generation connected to the grid when energy storage participates in frequency regulation, representing the change in frequency when the power changes by a unit amount. The larger K is, the smaller the frequency change is.

[0094] As new energy power generation continuously replaces traditional power generation, the proportion of traditional power generation decreases, resulting in a reduction in the system unit power regulation coefficient; however, the gain coefficient K B of energy storage increases the system unit regulation power coefficient, indirectly suppressing the impact of new energy power generation replacing traditional power generation on the system power-frequency regulation ability and improving the system frequency stability; in addition, the wind power frequency regulation coefficient c increases the value of the system unit regulation power coefficient.

[0095] The natural frequency ω n and the damping ratio ζ reflect the rapidity and smoothness of the grid frequency change. The smaller ω n and the larger ζ are, the better the system performance. As the proportion of new energy power generation increases, the proportion of traditional power generation decreases, resulting in a deterioration of the system's dynamic stability ability and weakening of the system's damping characteristics; and due to K B < 0, the time constant T B of the first-order inertia link of energy storage and the gain K B both participate in optimizing the natural frequency and damping ratio of the system, improving the system performance; in addition, the primary frequency regulation of wind power also improves the natural frequency and damping ratio.

[0096] Performing the Laplace inverse transform on the system frequency deviation response, the time-domain responses of the system under load and wind speed disturbances can be obtained as,

[0097]

[0098] Among them,

[0099]

[0100] Among them, φ1 and φ2 are the phase angles of the frequency response output and input respectively. The frequency index is a comprehensive evaluation of the frequency security of the power system. The important frequency indices on the frequency response curve under faults can effectively grasp the frequency response characteristics of the short-term dynamic process of the power system after being disturbed.

[0101] Common frequency indices include the extreme frequency, the maximum frequency change rate, and the quasi-steady-state frequency, etc. The specific expressions of the frequency indices of the system under load disturbances are as follows:

[0102] (1) Extreme frequency f nadir is the lowest point (when the power deficit is positive) or the highest point (when the power deficit is negative) in the transient change process of the power system frequency. Its magnitude is related to system inertia, spinning reserve, unit regulation power, etc. The extreme frequency deviation of this system load is

[0103] Δf nadir = Δf L (t nadir )

[0104] Among them, t nadir is the corresponding moment of the frequency extreme point, and

[0105]

[0106] (2) Frequency change rate λ RoCoF,max characterizes the speed of the power system frequency change after an accident. Its value is closely related to the magnitude of the active power disturbance and the system inertia level, and is an important measurement index for the activation of power system protection devices. The maximum frequency change rate of this system load is

[0107]

[0108] (3) Quasi-steady-state frequency f ss is the frequency value when the inertial center frequency of the power system returns to the quasi-steady-state operating point after being affected by the active power disturbance, and is an important basis for implementing secondary frequency adjustment. The quasi-steady-state frequency deviation of the system load is

[0109]

[0110] To visually show the internal relationship between different coefficients and the system frequency indices, Figures 3 - 5 are the frequency regulation change curves of the system under different traditional power generation ratios d G , energy storage gain coefficient K B and charge-discharge time constant T B respectively.

[0111] Figure 3Among them, the proportion of the traditional motor power generation capacity gradually decreases from 0.8 to 0.4. As the proportion decreases, when suffering from the same level of active power disturbance, the RoCoF (Rate of Change of Frequency) and the extreme frequency deviation of the system gradually increase. Figure 4 Among them, K B = 0 represents that there is no energy storage participating in frequency modulation. From the comparison between the curve of K B = 0 and other curves, it can be seen that when suffering from the same level of active power disturbance, the addition of the energy storage gain coefficient reduces the extreme frequency deviation of the system. And within the power limit range, as the absolute value of the energy storage gain coefficient, that is, the energy storage capacity, continuously increases, the extreme frequency deviation and the quasi-steady state frequency deviation of the system become smaller. However, regardless of whether there is energy storage in the system or how the energy storage capacity changes, the RoCoF of the system remains unchanged.

[0112] From Figure 5 it can be seen that the energy storage charge and discharge time constant has no influence on the system RoCoF and the quasi-steady state frequency difference. But as T B becomes smaller, the extreme frequency difference of the system becomes smaller, and the frequency overshoot becomes larger. Therefore, the energy storage has an optimization effect on the frequency index of the system, can improve the system's ability to resist frequency shocks, and thus improve the frequency stability of the power system.

[0113] Example 2, referring to Figure 6 and Figure 7 , is the second embodiment of the present invention. The difference from the first embodiment is that a wind-storage combined frequency modulation control method for a power system with a high proportion of new energy further includes determining different control modes according to the wind speed area where the wind turbine is located, specifically including: The requirement of high-penetration wind power grid connection is that the wind turbine has the ability to participate in frequency modulation. By linearizing the frequency control link equation, the wind power frequency response model can be obtained. The fan's different operating regions are divided according to the wind speed, and different wind speed disturbances correspond to different operating regions, which will be described in detail below.

[0114] Specifically, when the fan operates in the low wind speed area, the wind turbine adopts the maximum power point MPPT operation mode. In the low wind speed area, the available rotational kinetic energy that the fan can provide is extremely low. The fan cannot provide inertia support for the system and does not respond to the frequency dynamics of the power grid. Therefore, the power change in the low wind speed area and the transfer function G l (s) of the system frequency deviation and the transfer function G vl (s) of the fan power change caused by the wind speed disturbance in the low wind speed area are expressed as,

[0115] G l (s) = 0

[0116]

[0117] Among them, G vl(s) embodies the coordinated operation mode of virtual inertia and over-speed load shedding for wind turbines in the low wind speed area; s is a complex variable, g l and q l are the wind speed disturbance coefficients in the low wind speed area, and the formula is expressed as

[0118]

[0119] where ω is the rotor speed of the wind turbine, v is the wind speed, H t is the inertia constant of the wind turbine, k p is the proportionality factor, ρ is the air density, C p is the wind energy utilization coefficient, C p,max is the maximum value of the wind energy utilization coefficient, P base is the rated power, C Pref is the reference value of the wind energy utilization coefficient, k c is the partial derivative value of C p with respect to λ, λ is the tip speed ratio, λ ref is the reference value of the tip speed ratio.

[0120] Specifically, when the fan operates in the medium wind speed area, the wind turbine adopts a coordinated control mode of virtual inertia and over-speed load shedding. In the medium wind speed area, the wind turbine has sufficient reserve capacity to participate in primary frequency regulation, and an integrated frequency control strategy of virtual inertia control and over-speed load shedding control is adopted, as Figure 6 shown. This integrated operation mode enables the fan to respond to the change of the grid frequency and increase the system inertia through virtual inertia control, and enables the fan to obtain a certain amount of reserve power through over-speed load shedding control.

[0121] The power change in the medium wind speed area and the transfer function G m (s) of the power change of the fan caused by the wind speed disturbance in the medium wind speed area are expressed as vm (s)

[0122]

[0123] where G vm (s) embodies the coordinated operation mode of virtual inertia and over-speed load shedding for wind turbines in the medium wind speed area; a m and b m and c m are the wind power frequency modulation coefficients in the medium wind speed area, g m and q m are the wind speed disturbance coefficients in the medium wind speed area, and the formula is expressed as

[0124]

[0125] where d is the load shedding rate, ω dFor the rotor speed ω during power reduction operation m For the rotor speed k during maximum power operation v And R v Are virtual inertia control parameters.

[0126] Specifically, when the wind turbine operates in the high wind speed region, the wind power generation unit adopts a coordinated control method of virtual inertia and pitch angle. In the high wind speed region, the rotor speed of the wind turbine has reached the maximum limit, and load reduction operation cannot be achieved through overspeed control. At this time, the output power of the wind turbine can be adjusted through the pitch angle control method to participate in system frequency support, as Figure 7 Shown, when the wind speed is higher than the rated wind speed, the wind turbine has a constant power operation condition, and the output power of the wind turbine can be continuously adjusted by adjusting the pitch angle to respond to the change of the grid frequency.

[0127] The power change in the high wind speed region and the system frequency deviation transfer function G h (s) and the transfer function G vh (s) of the wind turbine power change caused by the wind speed disturbance in the high wind speed region are expressed as

[0128]

[0129] Among them, G vh (s) reflects the coordinated operation mode of virtual inertia and pitch angle control of the wind turbine in the high wind speed region; a h , b h , c h Are the wind power frequency modulation coefficients at high wind speed, g h , q h Are the wind speed disturbance coefficients in the high wind speed region, and the formula is expressed as

[0130]

[0131] Among them, K total,h = 2k p ω 3 + k p C Pref v 3 - k p k c ωv 2 , k β Is the partial derivative value of C p with respect to β, β is the pitch angle of the wind turbine, k b Is the frequency regulation proportionality coefficient introduced by pitch angle control.

[0132] Example 3, refer to Figures 8 - 15, which is the third embodiment of the present invention and is different from the previous two embodiments in that: a wind-storage combined frequency regulation control method for a power system with a high proportion of new energy further includes. To verify and illustrate the technical effects adopted in this method, in this embodiment, the experimental results are compared by means of scientific demonstration to verify the real effects of this method.

[0133] Adopt the improved IEEE9 bus system as Figure 8 shown for simulation verification. Replace the synchronous generator at bus 3 with a wind farm of the same capacity. The capacity of the energy storage is 20 MW·h, the maximum output power is 50 MW, the charge and discharge efficiency is 0.9, and the upper and lower limits of the state of charge are 0.9 and 0.1 respectively.

[0134] Comparison and verification before and after energy storage and wind power participate in frequency regulation

[0135] To verify the ability of energy storage and wind power to restore the system from faults during primary frequency regulation, set the simulation duration to 12 s, and the simulation condition is: at t = 1 s, a load disturbance of 0.1 pu occurs.

[0136] Wind power participates in frequency regulation (penetration rate d w = 40%), and the energy storage adjusts the system frequency on the basis of wind power frequency regulation at t = 6 s. The system frequency change is as Figure 9 shown; the comparison of frequency changes before and after adding energy storage frequency regulation on the basis of wind power primary frequency regulation is as Figure 10 shown.

[0137] Under different wind power penetration rates, the comparison of frequency changes with wind power primary frequency regulation and without wind power frequency regulation when the wind power penetration rate d w = 50% is as Figure 11 shown, and the comparison of the influence of the system frequency in different operating regions of the wind turbine is as Figure 12 shown.

[0138] Figure 9 In, under load disturbance, the frequency fluctuation of the system after adding the energy storage device to participate in frequency regulation is smaller than that of the system containing only traditional synchronous generator sets and wind power frequency regulation systems, which is mainly reflected in the extreme frequency and quasi-steady state frequency. Among them, the energy storage increases the extreme frequency of the system after disturbance by nearly 0.1 Hz and the quasi-steady state frequency by nearly 0.07 Hz.

[0139] Figure 10 In, the primary frequency regulation effect of wind power optimizes the frequency of the system after disturbance on the basis of energy storage frequency regulation, indicating that when energy storage participates in the frequency regulation of a high-penetration new energy system, the self-frequency regulation characteristics of new energy can cooperate with energy storage to improve its frequency regulation assistance effect (compared with traditional synchronous units) and enhance the system stability.

[0140] Figure 11In it, with the increase of the wind power penetration rate, due to the existence of wind power and energy storage frequency modulation, the system frequency is improved instead. This shows that the addition of wind power and energy storage frequency modulation can improve the system's ability to absorb wind power. Because during the process of continuously replacing the capacity of traditional units with new energy capacity, energy storage and wind power frequency modulation can make up for the inertia of the replaced units and provide frequency support for the system.

[0141] Figure 12 In it, since the fan has more sufficient margin to participate in the system primary frequency modulation in higher wind speed areas, the fan has the greatest effect on optimizing the system frequency when operating in high wind speed areas, followed by medium wind speed areas.

[0142] Table 1 Comparison of frequency indicators of different units in the system participating in frequency modulation

[0143]

[0144] Table 2 Comparison of frequency indicators during wind power frequency modulation under different penetration rates

[0145]

[0146] In Table 1, when receiving the same active power disturbance, wind power and energy storage can respectively provide frequency support for the system. Among them, when energy storage participates in frequency modulation, the extreme frequency deviation of the system after disturbance is optimized by 0.126 Hz and the quasi-steady-state frequency deviation is optimized by 0.162 Hz; the primary frequency modulation of wind power further optimizes the extreme frequency deviation and quasi-steady-state frequency deviation of the system under the same working conditions, optimizing the extreme frequency deviation by 0.038 Hz and the quasi-steady-state frequency deviation by 0.015 Hz.

[0147] In Table 2, the greater the wind power penetration rate means the greater the capacity of wind turbines participating in frequency modulation. With the increase of the wind power penetration rate, the frequency indicators of the system are optimized instead, indicating that the wind power control strategy plays a role in the system frequency support.

[0148] Frequency comparison when wind speed changes

[0149] The extended SFR considering wind speed disturbance can be more appropriate for the actual operation scenario. Set the simulation duration to 80 s, and the simulation conditions are: at t = 30 s, wind speed mutation disturbances are 0.5 m / s, 1 m / s, 1.5 m / s, and 2 m / s respectively. Figure 13 For the comparison of system frequency changes under different wind speed disturbances. It can be seen from the figure that the greater the wind speed mutation amount, the more obvious the frequency change caused to the system.

[0150] Set the simulation duration to 500 s, and the simulation conditions: add a wind speed disturbance model as Figure 14 shown. There is no load disturbance in the system, and the wind speed suddenly increases at t = 200 s and t = 400 s respectively, so that the fan operates in low, medium, and high wind speed areas at different times. Figure 15For the system frequency variation curve under this operating condition, it can be seen that the system frequency variation is consistent with Figure 14 the wind speed variation, and due to the adoption of different fan controls in different wind speed regions, the wind power has a more supportive role in regulating the frequency variation caused by wind speed disturbance in the system at high wind speeds.

[0151] Embodiment 4 is the fourth embodiment of the present invention. What is different from the previous three embodiments is: a wind energy storage combined frequency modulation control system for a power system with a high proportion of new energy, including a frequency detection module, a working condition judgment module, and a frequency regulation module; the frequency detection module is used to detect the frequency state of the power system. When the power system has a frequency change, based on the steady-state frequency response of the system, it judges the range where the measured system frequency f is located. If f is within the preset range, the energy storage frequency response is activated. If the system frequency deviation exceeds the range, the wind turbine is started for frequency modulation; the working condition judgment module is used to judge the wind speed region where the fan operates. The wind speed region divides different operating regions of the fan according to the wind speed, and different operating regions correspond to different wind speed disturbances; the frequency regulation module adopts a common regulation method of energy storage and wind turbines. Based on the transfer functions of different wind speed regions, the wind turbines adjust the system frequency to within the preset range, and then start the energy storage frequency regulation to restore the power system frequency to the normal level.

[0152] If the above-mentioned functions are implemented in the form of software function units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0153] The logic and / or steps represented in the flowchart or otherwise described herein can be considered as a definable sequence list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or used in conjunction with these instruction execution systems, apparatuses, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0154] More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection part (electronic device) having one or more wirings, a portable computer disk cartridge (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpretation, or other suitable processing when necessary, and then storing it in a computer memory.

[0155] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, any one or a combination of the following techniques well-known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application-specific integrated circuits having suitable combinational logic gate circuits, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0156] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A wind-storage combined frequency regulation control method for a power system with a high proportion of new energy, characterized in that: including When the frequency of the power system changes, based on the steady-state frequency response of the system, determine the range in which the measured system frequency f lies. If f is within the preset range, activate the energy storage frequency response; If the system frequency deviation exceeds the range, start the frequency regulation of the wind turbine generator set, and determine the wind speed area in which the wind turbine operates. The wind speed area divides different operating areas of the wind turbine according to the wind speed, and different operating areas correspond to different wind speed disturbances; Adopt a co-regulation method of energy storage and wind turbine generator set. Based on the transfer functions of different wind speed areas, the wind turbine generator set adjusts the system frequency to within the preset range, and then starts the energy storage frequency regulation to restore the power system frequency to the normal level.

2. The wind-storage combined frequency regulation control method for a power system with a high proportion of new energy as described in claim 1, wherein: That f is within the preset range includes 49.95Hz < f < 50.05Hz; The wind speed areas include high wind speed area, medium wind speed area and low wind speed area; The determination range of the high wind speed area is that the wind speed v is greater than or equal to 12m / s, and the determination range of the low wind speed area is that the wind speed v is less than 9m / s. When v ∈ [9, 12)m / s, it is determined as the medium wind speed area.

3. A wind storage combined frequency regulation control method for a power system with a high proportion of new energy as claimed in claim 2, characterized in that: The wind turbine adjusts the system frequency to a preset range, including when the wind turbine operates in a low wind speed area, the wind turbine adopts the maximum power point tracking (MPPT) operation mode. In the improved system of wind energy storage combined frequency modulation SFR frequency response, G w (s) = G l (s), G v (s) = G vl (s); When the fan operates in the medium wind speed area, the wind turbine adopts a coordinated control method of virtual inertia and overspeed load shedding. In the improved system SFR frequency response of wind storage combined frequency modulation, G w (s) = G m (s), G v (s) = G vm (s); When the wind turbine operates in the high wind speed region, the wind power generation unit adopts a coordinated control method of virtual inertia and pitch angle. In the improved system SFR frequency response of wind storage combined frequency modulation, G w (s) = G h (s), G v (s) = G vh (s); Among them, G w (s) represents the transfer function of power change and system frequency deviation, G v (s) represents the transfer function of the wind turbine power change caused by wind speed disturbance, G l (s) represents the transfer function of power change and system frequency deviation in the low wind speed area, G vl (s) represents the transfer function of the wind turbine power change caused by wind speed disturbance in the low wind speed area, G m (s) represents the transfer function of power change and system frequency deviation in the medium wind speed area, G vm (s) represents the transfer function of the wind turbine power change caused by wind speed disturbance in the medium wind speed area, G h (s) represents the transfer function of power change and system frequency deviation in the high wind speed area, G vh (s) represents the transfer function of the wind turbine power change caused by wind speed disturbance in the high wind speed area.

4. A wind-storage combined frequency regulation control method for a power system with a high proportion of new energy as claimed in claim 3, characterized in that: The improved system SFR of the wind-storage combined frequency regulation is a subsynchronous frequency response model for the frequency regulation of a new energy-integrated power grid with energy storage participation; The SFR includes recalculating the inertia of the power system based on the new energy grid connection volume, replacing conventional synchronous generators with wind turbines and photovoltaic power generation of the same capacity, and obtaining the transfer function G w (s) of the power change and the system frequency deviation and the transfer function G v (s) of the wind turbine power change caused by the wind speed disturbance.

5. A wind-storage combined frequency regulation control method for a power system with a high proportion of new energy as claimed in claim 4, characterized in that: When the wind turbine operates in the low wind speed region, the maximum power point tracking (MPPT) operation mode of the wind power generation unit includes that in the low wind speed region, the wind turbine cannot provide inertia support for the system and does not respond to the frequency dynamics of the power grid. Therefore, the power change in the low wind speed region and the transfer function G l (s) of the power change of the wind turbine caused by the wind speed disturbance in the low wind speed region and the transfer function G vl (s) are expressed as G l (s) = 0 Among them, G vl (s) reflects the coordinated operation mode of virtual inertia and overspeed load shedding of wind turbines in the low wind speed area; s is a complex variable, g l , q l are the wind speed disturbance coefficients in the low wind speed area, and the formula is expressed as where ω is the rotor speed of the wind turbine, v is the wind speed, H t is the inertia constant of the wind turbine, k p is the proportionality factor, ρ is the air density, C p is the wind energy utilization coefficient, C p,max is the maximum value of the wind energy utilization coefficient, P base is the rated power, C Pref is the reference value of the wind energy utilization coefficient, k c is the partial derivative value of C p with respect to λ, where λ is the tip speed ratio, λ ref is the reference value of the tip speed ratio.

6. The wind-storage combined frequency regulation control method for a power system with a high proportion of new energy as claimed in claim 5, wherein: When the wind turbine operates in the medium wind speed area, the coordinated control method of the wind turbine generator set using virtual inertia and overspeed load shedding includes that in the medium wind speed area, the wind turbine has sufficient reserve capacity to participate in primary frequency regulation. An integrated frequency control strategy of virtual inertia control and overspeed load shedding control is adopted. Through virtual inertia control, the wind turbine responds to the change of the grid frequency and increases the system inertia, and through overspeed load shedding control, the wind turbine can obtain a certain amount of reserve power; The transfer function G of the power change in the medium wind speed area with respect to the system frequency deviation m (s) and the transfer function G of the power change of the wind turbine caused by the wind speed disturbance in the medium wind speed area vm (s) are expressed as Among them, G vm (s) reflects the coordinated operation mode of virtual inertia and overspeed load shedding of wind turbines in the medium wind speed area; a m , b m , c m are the wind power frequency modulation coefficients in the medium wind speed area, and g m , q m are the wind speed disturbance coefficients in the medium wind speed area. It is expressed by the formula as follows: Among them, d is the load shedding rate, ω d is the rotor speed during load shedding power operation, ω m is the rotor speed during maximum power operation, k v and R v are virtual inertia control parameters.

7. A wind-storage combined frequency regulation control method for a power system with a high proportion of new energy as described in claim 6, characterized in that: When the wind turbine operates in the high wind speed area, the coordinated control method of the wind turbine generator set using virtual inertia and pitch angle includes that in the high wind speed area, the rotor speed of the wind turbine reaches the maximum limit, and load shedding operation cannot be carried out through overspeed control. The output power of the wind turbine is adjusted through the pitch angle control method to participate in the system frequency support; Power variation in the high wind speed area and the transfer function G h (s) and the transfer function G vh (s) caused by the wind speed disturbance in the high wind speed area are expressed as Among them, G vh (s) reflects the coordinated operation mode of the virtual inertia and pitch angle control of wind turbines in high wind speed areas; a h , b h , c h are the wind power frequency modulation coefficients at high wind speeds, g h , q h are the wind speed disturbance coefficients in high wind speed areas, and the formula is expressed as Among them, K total,h =2k p ω 3 +k p C Pref v 3 -k p k c ωv 2 , k β C p The partial derivative value of β, β is the pitch angle of the wind turbine, k b Frequency adjustment scaling factor introduced for pitch angle control.

8. A wind energy storage combined frequency regulation control system for a power system with a high proportion of new energy, applying a wind energy storage combined frequency regulation control method for a power system with a high proportion of new energy according to any one of claims 1 to 7, characterized in that: including a frequency detection module, a working condition judgment module and a frequency regulation module; The frequency detection module is used to detect the frequency state of the power system. When the frequency of the power system changes, based on the steady-state frequency response of the system, determine the range in which the measured system frequency f lies. If f is within the preset range, activate the energy storage frequency response. If the system frequency deviation exceeds the range, start the frequency regulation of the wind turbine generator set; The working condition judgment module is used to judge the wind speed area in which the wind turbine operates. The wind speed area divides different operating areas of the wind turbine according to the wind speed, and different operating areas correspond to different wind speed disturbances; The frequency regulation module adopts a co-regulation method of energy storage and wind turbine generator set. Based on the transfer functions of different wind speed areas, the wind turbine generator set adjusts the system frequency to within the preset range, and then starts the energy storage frequency regulation to restore the power system frequency to the normal level.

9. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that: When the processor executes the computer program, it implements the steps of a wind-storage combined frequency regulation control method for a power system with a high proportion of new energy as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, it implements the steps of a wind-storage combined frequency regulation control method for a power system with a high proportion of new energy as described in any one of claims 1 to 7.

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