Wind storage combined primary frequency modulation control method and system considering complex working conditions of source end

Abstract

The invention discloses a wind storage combined primary frequency modulation control method and system considering a complex working condition of a source end. The frequency modulation control method comprises the following steps: acquiring wind speed data and load data of a wind storage system; after a wind speed frequency deviation delta fwind determined according to the wind speed data and a load frequency deviation delta fs determined according to the load data pass through a dead zone, determining a wind speed change power according to the wind speed frequency deviation delta fwind, and determining a load change power according to the load frequency deviation delta fs; according to the wind speed change power and the load change power, determining a current preset working condition and calculating power required by frequency modulation; and according to the current preset working condition and the power required for frequency modulation, generating a fan droop control instruction or an energy storage droop control instruction for realizing frequency modulation on the wind storage system. The frequency adjusting capacity and the wind energy utilization rate of the wind storage system are improved, and the characteristics of the energy storage system can be brought into full play.

Description

Technical Field

[0001] The present application relates to the technical field of frequency modulation control, and in particular to a method and system for controlling wind-storage combined primary frequency modulation taking into account complex working conditions at the source end. Background Art

[0002] In recent years, the large-scale access of new energy sources such as wind power will have a great impact on the frequency stability of the power grid. At the same time, the advantages of the fast response speed of energy storage systems are becoming more and more obvious. Large-scale energy storage systems have become one of the necessary means to solve the problem of power grid frequency stability, but they also have shortcomings such as capacity loss and unreasonable power distribution. At present, in the new energy power system, the charging and discharging characteristics of the energy storage system, the coordinated control of wind power and energy storage systems in wind power-energy storage systems, and other issues have become bottlenecks in the development of new power systems.

[0003] At present, there have been relevant studies on the configuration of energy storage devices for wind turbines to participate in frequency regulation, including adding supercapacitors to the grid-side DC voltage bus, and combining virtual inertia control and droop control to control the capacitor charging and discharging power, so that the system frequency regulation effect can be greatly improved. However, many studies have ignored the problem of wind energy utilization of wind turbines. When energy storage is coordinated with wind turbines, the frequency regulation effect is often pursued, which leads to reduced wind energy utilization, excessive charging and discharging due to mismatch of energy storage power, and insufficient recovery of battery charge state. Some methods do not even design energy storage charging control schemes in the control scheme, and do not fully utilize the charging and discharging functions of energy storage. Summary of the invention

[0004] The content of this application is used to introduce concepts in a brief form, which will be described in detail in the detailed implementation section below. The content of this application is not intended to identify the key features or essential features of the technical solution claimed for protection, nor is it intended to limit the scope of the technical solution claimed for protection.

[0005] Some embodiments of the present application propose a wind-storage combined primary frequency modulation control method that takes into account complex working conditions at the source end to solve the technical problems mentioned in the above background technology section.

[0006] As a first aspect of the present application, some embodiments of the present application provide a wind-storage combined primary frequency regulation control method considering complex working conditions at the source end, including:

[0007] S100: Acquire wind speed data and load data of the wind storage system;

[0008] S200: determining the wind speed frequency deviation Δf according to the wind speed data wind , and a load frequency deviation Δf determined according to the load data s After all of them have passed the dead zone, according to the wind speed frequency deviation Δfwind Determine the wind speed change power and the load frequency deviation Δf s Determine load change power;

[0009] S300: Determine the current preset working condition and calculate the power required for frequency regulation according to the wind speed variation power and the load variation power;

[0010] S400: Generate a wind turbine droop control instruction or an energy storage droop control instruction for realizing frequency regulation of the wind-storage system according to the current preset operating condition and the power required for the frequency regulation.

[0011] Optionally, in some embodiments of the present application, step S200 includes:

[0012] When the wind speed frequency deviation Δf wind When it is less than a preset threshold, the wind speed change power is determined to be the wind speed reduction power P4;

[0013] When the wind speed frequency deviation Δf wind When it is greater than a preset threshold, the wind speed change power is determined to be the wind speed increase power P2;

[0014] When the load frequency deviation Δf s When it is less than a preset threshold, the load change power is determined to be the load reduction power P1;

[0015] When the load frequency deviation Δf s When it is greater than a preset threshold, the load change power is determined to be the load increase power P3.

[0016] Optionally, in some embodiments of the present application, the preset working conditions in step 300 include:

[0017] When the wind speed change power is the wind speed increase power P2, and the load change power is the load reduction power P1, determining that the current preset operating condition is the first operating condition;

[0018] When the wind speed change power is the wind speed reduction power P4, and the load change power is the load reduction power P1, if the sum of the wind speed reduction power P4 and the load reduction power P1 is less than 0, it is determined that the current preset operating condition is the second operating condition;

[0019] When the wind speed change power is the wind speed increase power P2, and the load change power is the load increase power P3, if the sum of the wind speed increase power P2 and the load increase power P3 is less than 0, it is determined that the current preset operating condition is the third operating condition;

[0020] When the sum of the wind speed reduction power P4 and the load reduction power P1 is greater than 0, it is determined that the current preset operating condition is the fourth operating condition;

[0021] When the sum of the wind speed increase power P2 and the load increase power P3 is greater than 0, it is determined that the current preset working condition is the fifth working condition;

[0022] When the wind speed change power is the wind speed reduction power P4, and the load change power is the load increase power P3, it is determined that the current preset operating condition is the sixth operating condition.

[0023] Optionally, in some embodiments of the present application, the preset working condition includes:

[0024] The first operating condition is used to indicate that the wind speed increases and the load decreases, the system needs to reduce power, and the wind turbine device in the wind storage system performs frequency modulation, or the energy storage device in the wind storage system performs frequency modulation;

[0025] The second operating condition is used to indicate that the wind speed decreases and the load decreases, the system cannot determine the power demand, and the wind turbine device in the wind storage system performs frequency modulation;

[0026] The third operating condition is used to indicate that the wind speed increases and the load increases, the system cannot determine the power demand, and the wind turbine device in the wind storage system performs frequency modulation;

[0027] The fourth operating condition is used to indicate that the wind speed decreases and the load decreases, the system cannot determine the power demand, and the energy storage device in the wind storage system performs frequency modulation;

[0028] The fifth operating condition is used to indicate that the wind speed increases and the load increases, the system cannot determine the power demand, and the energy storage device in the wind storage system performs frequency modulation;

[0029] The sixth operating condition is used to indicate that the wind speed decreases and the load increases, the system needs to increase power, and the energy storage device in the wind storage system performs frequency modulation.

[0030] Optionally, in some embodiments of the present application, the formula for the power ΔP required for frequency modulation is as follows:

[0031]

[0032] Among them, K cn is the adaptive droop coefficient of the energy storage device of the wind energy storage system, K p is the adaptive droop coefficient of the wind turbine device of the wind storage system, and the K cn With the K p is the consistent adaptive droop coefficient.

[0033] Optionally, in some embodiments of the present application, the adaptive droop coefficient K of the energy storage device of the wind energy storage system is cn Including discharge coefficient K cn_disch or / and charging factor K cn_ch ;

[0034] Among them, the discharge coefficient K cn_disch The formula is as follows:

[0035]

[0036] Among them, the charging coefficient K cnch The formulas are as follows:

[0037] Among them, K M K cn The maximum value of S max , S min and S low are respectively the maximum value, minimum value and preset intermediate value of the energy storage charge state S; a is the adaptive factor.

[0038] As a second aspect of the present application, some embodiments of the present application further provide a wind-storage combined primary frequency regulation control system considering complex working conditions at the source end, including:

[0039] Data module, used to obtain wind speed data and load data of wind storage system;

[0040] A determination module is used to determine the wind speed frequency deviation Δf according to the wind speed data. wind , and a load frequency deviation Δf determined according to the load data s After all of them have passed the dead zone, according to the wind speed frequency deviation Δf wind Determine the wind speed change power and the load frequency deviation Δf s Determine load change power;

[0041] A power module, used to determine the current preset working condition and calculate the power required for frequency regulation according to the wind speed change power and the load change power;

[0042] The instruction module is used to generate a wind turbine droop control instruction or an energy storage droop control instruction for realizing frequency regulation of the wind-storage system according to the current preset working condition and the power required for the frequency regulation.

[0043] Optionally, in some embodiments of the present application, the determination module determines the wind speed frequency deviation Δf windWhen the wind speed is less than a preset threshold, the wind speed change power is determined to be the wind speed reduction power P4 or / and the wind speed change power is determined to be the wind speed increase power P2;

[0044] The determination module determines the load frequency deviation Δf s When it is less than a preset threshold, the load change power is determined to be the load reduction power P1 or / and the load change power is determined to be the load increase power P3.

[0045] Optionally, in some embodiments of the present application, when the wind speed change power is the wind speed increase power P2 and the load change power is the load reduction power P1, the power module determines that the current preset operating condition is the first operating condition;

[0046] The power module determines that the current preset operating condition is the second operating condition when the wind speed change power is the wind speed reduction power P4 and the load change power is the load reduction power P1 and if the sum of the wind speed reduction power P4 and the load reduction power P1 is less than 0;

[0047] The power module determines that the current preset operating condition is the third operating condition when the wind speed change power is the wind speed increase power P2 and the load change power is the load increase power P3 and if the sum of the wind speed increase power P2 and the load increase power P3 is less than 0;

[0048] When the sum of the wind speed reduction power P4 and the load reduction power P1 is greater than 0, the power module determines that the current preset operating condition is the fourth operating condition;

[0049] When the sum of the wind speed increase power P2 and the load increase power P3 is greater than 0, the power module determines that the current preset working condition is the fifth working condition;

[0050] The power module determines that the current preset operating condition is the sixth operating condition when the wind speed change power is the wind speed reduction power P4 and the load change power is the load increase power P3;

[0051] The first operating condition is used to indicate that the wind speed increases and the load decreases, the system needs to reduce power, and the wind turbine device in the wind storage system performs frequency modulation, or the energy storage device in the wind storage system performs frequency modulation;

[0052] The second operating condition is used to indicate that the wind speed decreases and the load decreases, the system cannot determine the power demand, and the wind turbine device in the wind storage system performs frequency modulation;

[0053] The third operating condition is used to indicate that the wind speed increases and the load increases, the system cannot determine the power demand, and the wind turbine device in the wind storage system performs frequency modulation;

[0054] The fourth operating condition is used to indicate that the wind speed decreases and the load decreases, the system cannot determine the power demand, and the energy storage device in the wind storage system performs frequency modulation;

[0055] The fifth operating condition is used to indicate that the wind speed increases and the load increases, the system cannot determine the power demand, and the energy storage device in the wind storage system performs frequency modulation;

[0056] Among them, the sixth operating condition is used to indicate that the wind speed decreases and the load increases, the system needs to increase power, and the energy storage device in the wind storage system performs frequency modulation.

[0057] Optionally, in some embodiments of the present application, the power module calculates the power ΔP required for the frequency modulation using the following formula:

[0058]

[0059] Among them, K cn is the adaptive droop coefficient of the energy storage device of the wind energy storage system, K p is the adaptive droop coefficient of the wind turbine device of the wind storage system, and the K cn With the K p is the consistent adaptive droop coefficient;

[0060] The adaptive droop coefficient K of the energy storage device of the wind storage system cn Including discharge coefficient K cn_disch or / and charging factor K cn_ch ;

[0061] Among them, the discharge coefficient K cn_disch The formula is as follows:

[0062]

[0063] Among them, the charging coefficient K cn_ch The formulas are as follows:

[0064]

[0065] Among them, K M K cn The maximum value of S max , S min and S low are respectively the maximum value, minimum value and preset intermediate value of the energy storage charge state S; a is the adaptive factor.

[0066] The beneficial effect of the present application is that it provides a wind-storage combined primary frequency modulation control method and system that can improve energy storage utilization and take into account complex working conditions at the source end.

[0067] More specifically, some embodiments of the present application may produce the following specific beneficial effects:

[0068] The frequency regulation capability and wind energy utilization rate of the wind storage system have been improved, and the characteristics of the energy storage system, such as stable performance, flexible control and rapid response, have been fully utilized, thus reducing the impact on the power grid caused by frequency changes.

[0069] By utilizing the rapid response characteristics of the battery energy storage system, the energy generated by the wind turbine is converted into electrical energy, enabling the wind turbine and energy storage to cooperate in grid frequency regulation.

[0070] This application takes into account the charging and discharging functions of energy storage, improves the utilization rate of energy storage, and makes the frequency deviation of the wind storage system lower and the frequency regulation time shorter after one frequency regulation, thereby achieving the purpose of improving the frequency regulation effect and obtaining a higher wind energy utilization rate.

[0071] In order to solve the power mismatch problem caused by inconsistent coefficients when switching working conditions, the present application matches the droop coefficient of the wind turbine and the droop coefficient of the energy storage to obtain more accurate power instructions, avoid excessive supplementation of power shortage by energy storage, and obtain better frequency recovery effect.

[0072] The adaptive droop coefficient proposed in the present application has a better recovery effect on the state of charge of the energy storage, greatly improves the utilization rate of the energy storage, and improves the frequency modulation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] The drawings constituting a part of this application are used to provide a further understanding of this application, so that other features, purposes and advantages of this application become more obvious. The illustrative embodiment drawings and their descriptions of this application are used to explain this application and do not constitute an improper limitation on this application.

[0074] In addition, throughout the drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic and that the components and elements are not necessarily drawn to scale.

[0075] In the attached picture:

[0076] Figure 1 This is a schematic diagram of the wind-storage system architecture adopted by the wind-storage combined primary frequency modulation control method and system considering complex source-end working conditions provided by this application;

[0077] Figure 2 It is a schematic diagram of a frequency dynamic response model of a wind-storage system of a wind-storage combined primary frequency modulation control method and system considering complex source-end working conditions provided by the present application;

[0078] Figure 3 It is a schematic diagram of the frequency separation control principle of the wind-storage system of the wind-storage combined primary frequency modulation control method and system provided by the present application considering the complex working conditions at the source end;

[0079] Figure 4 It is a flow chart of the steps of the wind-storage combined primary frequency modulation control method considering the complex working conditions at the source end provided by this application;

[0080] Figure 5 This is the control logic block diagram of the first frequency regulation control scheme (inconsistent adaptive droop coefficient) of the wind-storage combined primary frequency regulation control method considering complex source-end working conditions provided by this application;

[0081] Figure 6 It is a schematic diagram of the energy storage output of the first frequency regulation control scheme (inconsistent adaptive droop coefficients) and the second frequency regulation control scheme (consistent adaptive droop coefficients) of the wind-storage combined primary frequency regulation control method considering complex source-end working conditions provided by the present application;

[0082] Figure 7 It is a schematic diagram of the frequency deviation between the first frequency modulation control scheme (inconsistent adaptive droop coefficients) and the second frequency modulation control scheme (consistent adaptive droop coefficients) of the wind-storage combined primary frequency modulation control method considering complex source-end working conditions provided by the present application;

[0083] Figure 8 It is a power schematic diagram of the first frequency modulation control scheme (inconsistent adaptive droop coefficients) and the second frequency modulation control scheme (consistent adaptive droop coefficients) of the wind-storage combined primary frequency modulation control method considering complex source-end working conditions provided by the present application when the working conditions are switched;

[0084] Fig. 9 This is a control logic block diagram of the second frequency regulation control scheme (with consistent coefficients) of the wind-storage combined primary frequency regulation control method provided by the present application considering complex working conditions at the source end;

[0085] Fig.10 This is a control flow chart of the second frequency regulation control scheme of the wind-storage combined primary frequency regulation control method considering complex working conditions at the source end provided by the present application;

[0086] Fig.11 It is a schematic diagram of the frequency deviation between the first frequency control scheme and the second frequency control scheme of the wind-storage combined primary frequency control method considering the complex working conditions at the source end provided by the present application and the existing frequency control method with a fixed energy storage droop coefficient;

[0087] Fig.12It is a schematic diagram of the energy storage output power of the first frequency modulation control scheme and the second frequency modulation control scheme of the wind-storage combined primary frequency modulation control method considering the complex working conditions at the source end provided by the present application and the existing frequency modulation control method with a fixed energy storage droop coefficient;

[0088] Fig.13 The rotor speed and S of the first frequency control scheme and the second frequency control scheme of the wind-storage combined primary frequency control method considering the complex working conditions at the source end provided by this application are compared with the existing frequency control method with a fixed energy storage droop coefficient. OC Schematic diagram of the changes;

[0089] Fig.14 yes Fig.11 Schematic diagram of frequency deviation in the period from 80s to 120s;

[0090] Fig.15 It is a schematic diagram of a wind-storage combined primary frequency regulation control system adopted by the second frequency regulation control scheme of the wind-storage combined primary frequency regulation control method that takes into account complex working conditions at the source end provided in this application. DETAILED DESCRIPTION

[0091] Embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present application. It should be understood that the drawings and embodiments of the present application are only for exemplary purposes and are not intended to limit the scope of protection of the present application.

[0092] It should also be noted that, for ease of description, only the parts related to the invention are shown in the drawings. In the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other.

[0093] It should be noted that the concepts such as "first" and "second" mentioned in this application are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0094] It should be noted that the modifications of "one" and "plurality" mentioned in the present application are illustrative rather than restrictive, and those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0095] The names of the messages or information exchanged between multiple devices in the embodiments of the present application are only used for illustrative purposes and are not used to limit the scope of these messages or information.

[0096] The present application will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0097] Reference Figure 1 As shown, the wind energy storage system of the present application mainly includes: a wind farm, an energy storage device, a power converter and a load. The energy storage device in the wind energy storage system is used to achieve frequency regulation.

[0098] The wind storage system can use a bidirectional DC / AC converter to control the charging and discharging of the energy storage device. The active power generated by the wind farm and the charging power of the batteries in the battery pack of the energy storage device are controlled by the bidirectional DC / AC converter and connected to the AC power grid.

[0099] Reference Figure 2 As shown, Figure 2 The frequency dynamic response model of a single-machine system in the wind storage system of the present application is shown as an example.

[0100] The frequency response model is expressed as follows:

[0101]

[0102] Among them, P D is the load disturbance; P W is wind power; P M is the output power of the synchronous generator; Δf is the system frequency deviation.

[0103] In this frequency dynamic response model, in the formula In it, H is the inertia time constant of the power grid, D is the damping coefficient of the power grid, and s is the Laplace operator.

[0104] In this frequency dynamic response model, in the formula In, K m is the mechanical power gain coefficient, F H is the power generated by the high pressure steam turbine unit, T R is the reheating time constant, s is the Laplace operator, R is the droop coefficient of the synchronous generator, and the calculation result of this formula is defined as G(s) in the following text.

[0105] In order to better respond to wind power and load power fluctuations, the frequency deviation caused by wind power and load power fluctuations is separated and used to set the power command. The specific method is as follows:

[0106] If the wind power and the output power of the synchronous generator do not change, that is, P W and P M The system frequency deviation Δf caused by load power fluctuation is s The expression of the system transfer function is:

[0107]

[0108] Correspondingly, the expression of the system transfer function of the system frequency deviation caused by wind power fluctuation is:

[0109]

[0110] Reference Figure 3 As shown in the figure, the separated signals are used to determine the power shortage of the source and load ends on the one hand, and to calculate the power command required by the control scheme on the other hand, and send it to the wind turbine controller or energy storage controller for power distribution. Among them, the wind turbine controller (hereinafter referred to as wind control) adopts comprehensive inertial control combining droop control and virtual inertial control, and the energy storage controller (hereinafter referred to as storage control) adopts droop control.

[0111] The load fluctuation power of the wind storage system itself is partially compensated by wind power, and the other part is compensated by energy storage droop control or wind turbine droop control power. Therefore, calculation is required to obtain the power difference required for frequency regulation. The power difference can correspond to the power shortage of energy storage or the power supplement provided by the wind turbine. For the sake of ease of introduction, the power difference required for frequency regulation is defined as: power required for frequency regulation ΔP.

[0112] See also Figure 4 , Figure 4 This is a flow chart of the steps of a wind-storage combined primary frequency modulation control method considering complex working conditions at the source end provided by this application. Figure 4 As shown, the frequency modulation control method includes the following steps:

[0113] S100: Acquire wind speed data and load data of the wind storage system;

[0114] S200: determining the wind speed frequency deviation Δf according to the wind speed data wind , and a load frequency deviation Δf determined according to the load data s After all of them have passed the dead zone, according to the wind speed frequency deviation Δf wind Determine the wind speed change power and the load frequency deviation Δf s Determine load change power;

[0115] S300: Determine the current preset working condition and calculate the power required for frequency regulation according to the wind speed variation power and the load variation power;

[0116] S400: Generate a wind turbine droop control instruction or an energy storage droop control instruction for realizing frequency regulation of the wind-storage system according to the current preset operating condition and the power required for the frequency regulation.

[0117] In some embodiments, specifically, step S200 includes:

[0118] When the wind speed frequency deviation Δf wind When it is less than a preset threshold, the wind speed change power is determined to be the wind speed reduction power P4;

[0119] When the wind speed frequency deviation Δf wind When it is greater than a preset threshold, the wind speed change power is determined to be the wind speed increase power P2;

[0120] When the load frequency deviation Δf s When it is less than a preset threshold, the load change power is determined to be the load reduction power P1;

[0121] When the load frequency deviation Δf s When it is greater than a preset threshold, the load change power is determined to be the load increase power P3.

[0122] Taking into account the uncertainty of random fluctuations of load and wind speed at the same time, this application starts from the changes in the source end and the load end, and subdivides them into six different working conditions, so as to realize the coordinated participation of wind turbines and energy storage in frequency modulation. The specific situation is: six operating conditions (condition one, condition two, condition three, condition four, condition five and condition six) are designed according to the load and wind speed fluctuations, and the set criteria are used to achieve switching between different operating conditions. The details of the six operating conditions are shown in Table 1. Among them, condition one, condition two, condition three, condition four, condition five and condition six are respectively defined as the first condition (referred to as condition one), the second condition (referred to as condition two), the third condition (referred to as condition three), the fourth condition (referred to as condition four), the fifth condition (referred to as condition five) and the sixth condition (referred to as condition six).

[0123] Table 1 Wind speed changes, load changes, power shortages, switching rules, and frequency modulation options corresponding to the operating conditions of the wind storage system of this application

[0124]

[0125]

[0126] Based on Table 1, optionally, the above step S300 includes:

[0127] When the wind speed change power is the wind speed increase power P2, and the load change power is the load reduction power P1, determining that the current preset operating condition is the first operating condition;

[0128] When the wind speed change power is the wind speed reduction power P4, and the load change power is the load reduction power P1, if the sum of the wind speed reduction power P4 and the load reduction power P1 is less than 0, it is determined that the current preset operating condition is the second operating condition; if the sum of the wind speed reduction power P4 and the load reduction power P1 is greater than 0, it is determined that the current preset operating condition is the fourth operating condition;

[0129] When the wind speed change power is the wind speed increase power P2, and the load change power is the load increase power P3, if the sum of the wind speed increase power P2 and the load increase power P3 is less than 0, it is determined that the current preset operating condition is the third operating condition; if the sum of the wind speed increase power P2 and the load increase power P3 is greater than 0, it is determined that the current preset operating condition is the fifth operating condition;

[0130] When the wind speed change power is the wind speed reduction power P4, and the load change power is the load increase power P3, it is determined that the current preset operating condition is the sixth operating condition.

[0131] Among them, the first operating condition is used to indicate that the wind speed increases and the load decreases, the system needs to reduce power, and the wind turbine device in the wind storage system performs frequency modulation, or the energy storage device in the wind storage system performs frequency modulation; the second operating condition is used to indicate that the wind speed decreases and the load decreases, the system cannot judge the power demand, and the wind turbine device in the wind storage system performs frequency modulation; the third operating condition is used to indicate that the wind speed increases and the load increases, the system cannot judge the power demand, and the wind turbine device in the wind storage system performs frequency modulation; the fourth operating condition is used to indicate that the wind speed decreases and the load decreases, the system cannot judge the power demand, and the energy storage device in the wind storage system performs frequency modulation; the fifth operating condition is used to indicate that the wind speed increases and the load increases, the system cannot judge the power demand, and the energy storage device in the wind storage system performs frequency modulation; the sixth operating condition is used to indicate that the wind speed decreases and the load increases, the system needs to increase the power, and the energy storage device in the wind storage system performs frequency modulation.

[0132] The following introduces the wind-storage combined primary frequency regulation control method considering complex working conditions at the source end provided in this application from two aspects: the first frequency regulation control scheme based on inconsistent adaptive droop coefficients (inconsistent adaptive droop coefficients) and the second frequency regulation control scheme based on consistent adaptive droop coefficients (consistent adaptive droop coefficients).

[0133] Table 2 Wind speed change, load change, power shortage, switching rules, and frequency modulation selection corresponding to the operating conditions of the first frequency modulation control scheme

[0134]

[0135] See also Figure 5 and Table 2, Figure 5 This is a control logic block diagram of a wind-storage combined primary frequency modulation control method (the first frequency modulation control scheme, the adaptive droop coefficient is inconsistent) provided by this application considering the complex working conditions of the source end. Table 2 is the wind speed change, load change, power shortage, switching rules, and frequency modulation selection corresponding to the operating conditions of the first frequency modulation control scheme. Figure 5 As shown in the figure, the power ΔP required for frequency regulation provided by the wind storage system is obtained by the following formula:

[0136] ΔP=K drop Δf s +K SCSS Δf wind

[0137] Among them, K SCSS is the energy storage adaptive droop coefficient, K drop K is the fan adaptive droop coefficient. drop With K SCSS The designed values ​​are all negative. In the study, it was found that when the fan adaptive droop coefficient K drop And the energy storage adaptive droop coefficient K SCSS If the calculated value is inconsistent, it is possible that the power supplement will be inaccurate when frequency regulation is performed. The reason is that when the wind power change is opposite to the load power change and can compensate for each other, the following relationship exists:

[0138] |Δf s |=|Δf wind |

[0139] At this time, no additional frequency modulation power is needed to supplement. However, due to the wind turbine adaptive droop coefficient K drop And the energy storage adaptive droop coefficient K SCSS If they are inconsistent, a non-zero power required for frequency regulation ΔP will be calculated, causing the wind storage system to output incorrect power demand and cause excessive frequency regulation.

[0140] For example, if K drop The absolute value of K is larger. At this time, the fan needs to reduce power output. Assume that the power reduction of the fan is ΔP1. SCSS If the absolute value of is larger, energy storage discharge is required to supplement the power shortage. Assume that the discharge power is ΔP2. The above two cases are both cases of over-compensation of power shortage. The formulas of ΔP1 and ΔP2 are as follows:

[0141]

[0142] In view of this, the present application provides a second frequency regulation control scheme based on the consistency of adaptive droop coefficient on the basis of the first frequency regulation control scheme. The second frequency regulation control scheme demonstrates a wind-storage combined primary frequency regulation control method and system that considers complex working conditions at the source end, further improving the control effect of the wind-storage combined participation in the primary frequency regulation of the power grid and the wind energy utilization rate of the wind turbines.

[0143] The control logic block diagram of a wind-storage combined primary frequency modulation control method (the second frequency modulation control scheme and the adaptive droop coefficient are consistent) in this application considering the complex working conditions at the source end is as follows: Fig. 9 The blue dotted box indicates the maximum power point tracking control of the wind turbine, the orange dotted box indicates the power command of the integrated inertia control of the wind turbine, the purple dotted box indicates the power command of the energy storage droop control, the green dotted box indicates the increase and decrease judgment of the load and wind speed and the calculation of the power command, and the red dotted box indicates the operating condition switching rule.

[0144] Table 3 Wind speed change, load change, power shortage, switching rules, and frequency modulation selection corresponding to the operating conditions of the second frequency modulation control scheme

[0145]

[0146] Reference Fig. 9 As shown, the control logic block diagram of the second frequency modulation control scheme (adaptive droop coefficient is consistent) of the wind storage combined primary frequency modulation control method considering complex working conditions at the source end provided by this application, Table 3 is the wind speed change, load change, power shortage, switching rules, and frequency modulation selection corresponding to the operating conditions of the second frequency modulation control scheme. The formula used in the mathematical model of the wind storage combined primary frequency modulation control method (second frequency modulation control scheme, adaptive droop coefficient is consistent) considering complex working conditions at the source end of this application is:

[0147] P W =P MPPT +P5+P drop

[0148] P total =P W +P cn

[0149] Among them, P MPPT is the maximum power tracking; P cn The output power is controlled by energy storage droop; P drop P is the fan droop control power; total It is the sum of wind power and energy storage power; P5 is the power required for the wind turbine to provide inertial support during the entire frequency regulation process.

[0150]

[0151] Among them, P5 can be calculated by the following formula:

[0152] In the formula, K f is the inertia control coefficient, f s is the frequency of the power grid.

[0153] like Fig. 9 As shown in the figure, the operating conditions 1 (first operating condition), 4 (fourth operating condition), 5 (fifth operating condition) and 6 (sixth operating condition) are energy storage droop control, the operating conditions 2 (second operating condition) and 3 (third operating condition) are fan droop control, 7 represents the output power of energy storage, and 8 represents the output power of fan droop control. Δf s is the frequency change caused by load change, that is, load frequency deviation; Δf wind is the frequency change caused by wind speed change, that is, wind speed frequency deviation; K p is the adaptive droop control coefficient of the fan device considering the power matching when the working condition is switched; K cn is the adaptive droop control coefficient of the energy storage device considering the power matching when the working condition switches; cn_1 P is the power required for energy storage to participate in frequency regulation in the first working condition; cn_2 P is the power required for energy storage to participate in frequency regulation in the sixth working condition; sel_1 P is the power required for frequency modulation in the second and fourth working conditions; sel_2 P is the power required for frequency modulation in the third and fifth working conditions; cn The output power is controlled by energy storage droop; P drop P is the fan droop control power; W is wind power; P total It is the sum of wind power and energy storage power.

[0154] It should be particularly noted that in order to distinguish the two frequency regulation control schemes of the wind-storage combined primary frequency regulation control method that takes into account complex working conditions at the source end provided in this application, the adaptive droop control coefficients of the wind turbine devices in the two frequency regulation control schemes are represented by different parameters, and the adaptive droop control coefficients of the energy storage devices are represented by different parameters.

[0155] According to the "Test Methods for Wind Turbines", the frequency modulation dead zone is set to |Δf|≤0.03Hz. Considering that energy storage charging and discharging will consume its life, and taking advantage of wind turbine control, this application adopts a control scheme for wind turbine and energy storage combined frequency modulation (the second frequency modulation control scheme and the adaptive droop coefficient are consistent). The control process based on the model and formula of the second frequency modulation control scheme is referenced. Fig.10 As shown, the details are as follows:

[0156] S1: Detect wind speed and load simultaneously;

[0157] S2: Calculate wind speed frequency deviation Δf wind and load frequency deviation Δf s And the wind speed frequency deviation Δf wind and load frequency deviation Δf s After passing through the dead zone, according to Δf wind Is it less than -0.03? The wind speed increases the power P2, the wind speed decreases the power P4, and Δf s Whether the value is less than -0.03, the value of load reduction power P1 and the value of load increase power P3 are obtained;

[0158] S3: Calculate the power P obtained by adding the load reduction power P1 and the wind speed reduction power P4 sel_1 , the power P obtained by adding the wind speed increase power P2 and the load increase power P3 sel_2 , and respectively determine whether the two are <0, and calculate the power P required for the energy storage to participate in frequency regulation in the working condition by the load reduction power P1 and the wind speed increase power P2 cn_1 The power P required for energy storage to participate in frequency regulation in working condition 6 is calculated by the load increase power P3 and wind speed decrease power P4 cn_2 ;

[0159] S4: Combined with P sel_1 and P sel_2 The judgment result, P cn_1 and P cn_2 The value of the inertial control P5 is used to output the fan droop control command (when P sel_1 or P sel_2 When it is less than 0, the wind turbine droop control power participates in frequency modulation) and the wind turbine virtual inertia control command, or the energy storage droop control command and the wind turbine virtual inertia control command.

[0160] From the above, the working conditions and judgment methods of the second frequency modulation control scheme are summarized as follows:

[0161] The first working condition: wind speed and load disturbance are detected at the same time, and the frequency modulation dead zone is set. When the system load decreases and needs to provide load reduction power P1 and wind speed increases and needs to provide wind speed increase power P2, it switches to the first working condition. At this time, the power P charged by energy storage cn_1 = (P1+P2). In addition, the power when the wind turbine provides the required inertial support is P5.

[0162] When the load and wind speed decrease at the same time, it can be divided into the second and fourth working conditions; when the load and wind speed increase at the same time, it can be divided into the third and fifth working conditions.

[0163] The second and fourth working conditions: when the load is reduced, the load reduction power P1 needs to be provided, and at the same time, the wind speed reduction power P4 needs to be provided. At this time, the sum of the powers of the two (i.e., P sel_2 =P1+P4) is compared with 0. sel_2 When it is less than 0, it switches to the second working condition, and the fan adopts droop control to achieve frequency modulation; when P sel_2 When it is greater than 0, it switches to the fourth operating condition, and the energy storage uses droop control to achieve frequency regulation. In addition, the wind turbine provides the required inertial support power P5.

[0164] The third and fifth working conditions: When the load increases and the load increase power P3 is required, and the wind speed increases and the wind speed increase power P2 is required, the sum of the two powers (i.e., P sel_1 =P2+P3) is compared with 0. sel_1 When it is less than 0, it switches to the third working condition, and the fan adopts droop control to achieve frequency modulation; when P sel_1 When it is greater than 0, it switches to the fifth operating condition, and the energy storage uses droop control to achieve frequency regulation. In addition, the wind turbine provides the required inertial support when the power P5.

[0165] The sixth working condition: when the load increases and the load increase power P3 is required and the wind speed decreases and the wind speed decrease power P4 is required, the system switches to working condition 6. At this time, the power P input from the energy storage device to the grid through the grid-side converter is cn_2 =P3+P4. In addition, the power when the wind turbine provides the required inertial support is P5.

[0166] When the adaptive droop coefficient is consistent, the energy storage output is compared with the energy storage output when the adaptive droop coefficient is inconsistent (output in the fourth working condition). Figure 6 When the adaptive droop coefficients are inconsistent, the output increases significantly, that is, the power required for frequency regulation calculated by ΔP is inaccurate, and the power deficit is too much, resulting in an increase in frequency deviation. The frequency deviation comparison is as follows: Figure 7 shown.

[0167] In addition to the above power mismatch problem, the first frequency modulation control scheme based on inconsistent adaptive droop coefficients also has the following shortcomings:

[0168] There are many conditions for energy storage to discharge in the frequency smoothing control process. When the power ΔP required for frequency modulation is greater than 0, that is, when positive power needs to be supplemented, it switches to energy storage control to participate in frequency modulation. The conditions for switching to energy storage discharge in its operating condition rules include the fourth, fifth and sixth conditions shown in Tables 1 to 3 above. Therefore, the energy storage discharge of the first frequency modulation control scheme will quickly reach the lower limit of the battery, and the initial capacity demand for energy storage is high, and the cost also increases accordingly.

[0169] In this way, the frequency regulation effect of energy storage will become worse and worse, and because the adaptive droop coefficient of energy storage is very low, the calculated power required for frequency regulation ΔP value is always less than 0. Therefore, it should switch to the energy storage frequency regulation of the fourth working condition, but because the coefficient does not match, the power required for frequency regulation ΔP is less than 0 and it switches to the fan droop control of the second working condition, resulting in the problem of wrong working condition switching.

[0170] like Figure 8 As shown, Figure 8 The difference in the power ΔP required for frequency modulation corresponding to different coefficients is shown, which is opposite in positive and negative, leading to incorrect judgment of the working condition.

[0171] Compared with the first frequency modulation control scheme, the second frequency modulation control scheme adopts a consistent adaptive droop coefficient to avoid power over-compensation and misjudgment of operating conditions, thereby improving the frequency modulation effect. In addition, the second frequency modulation control scheme charges the energy storage instead of reducing the power output of the wind turbine under the first operating condition, and sets an adaptive droop coefficient for the energy storage, which fully utilizes the charging and discharging functions of the energy storage and takes into account both the frequency modulation requirements and the charge state of the energy storage.

[0172] This application controls the uncertainty of random fluctuations of load and wind speed by the above six working conditions, among which: Figure 6 and Figure 7 The second frequency regulation control scheme shown in the figure gives full play to the characteristics of stable performance, flexible control and fast response of the energy storage system, and makes full use of the frequency regulation capability of the wind turbine itself, and achieves grid frequency stability by adjusting the output of the wind turbine, reducing the impact on the grid caused by frequency changes. By utilizing the fast response characteristics of the battery energy storage system, the energy generated by the wind turbine is converted into electrical energy, and the wind turbine and energy storage cooperate to participate in grid frequency regulation.

[0173] For the first working condition (load reduction and wind speed increase), the second frequency control scheme changes the first frequency control scheme where the wind turbine uses droop control to participate in frequency regulation to the energy storage using droop control to participate in frequency regulation, that is, the power command under this working condition is passed to the energy storage, allowing the energy storage to achieve frequency regulation. Ultimately, the charging function of the energy storage can be realized, and the frequency regulation effect of the energy storage is better than that of the original wind turbine. Secondly, the wind energy utilization rate of the wind turbine is also improved.

[0174] In view of the problem that the adaptive droop coefficient is inconsistent when comparing the sum of power with 0 in the second and fourth working conditions, resulting in excessive power shortage and inaccurate working condition switching, the present application sets an adaptive droop coefficient K matching the fan device for the energy storage device. cn , that is, let the adaptive droop coefficient K of the fan device p Adaptive droop coefficient K of energy storage device cn Keep consistent, that is, K cn =Kp .

[0175] In this way, when comparing power, it is possible to avoid situations where energy storage or excessive output of wind turbines due to different coefficients leads to over-compensation of power shortages and inaccurate switching. The improved calculation formula for the power ΔP required for frequency regulation is as follows:

[0176] ΔP=K p Δf s +K cn Δf wind

[0177] When the adaptive droop coefficient K of the fan device with the same adaptive droop coefficient is used p Adaptive droop coefficient K of energy storage device cn When the wind speed and load increase or decrease at the same time, the power ΔP required for frequency regulation can be accurately calculated.

[0178]

[0179] Among them, K cn is the adaptive droop coefficient of the energy storage device of the wind energy storage system, K p is the adaptive droop coefficient of the wind turbine device in the wind storage system.

[0180] In order to prevent the S OC The state of charge (State of Charge, here refers to the state of charge of the energy storage device, generally refers to the ratio of the current charge to the rated charge, hereinafter also referred to as the energy storage charge state S) quickly reaches the upper and lower limits, affecting the frequency modulation effect of the energy storage device. This application improves its original adaptive droop coefficient and adopts the Sigmod function (abbreviated as S-type function) curve, which can make the S of the energy storage device OC Maintain within a moderate range and participate in frequency regulation with optimal output. K cn Can be divided into a discharge coefficient K cn_disch , a charging factor K cn_ch , as shown in the following formula:

[0181]

[0182] Among them, K M is the adaptive droop coefficient K of the energy storage device cn The maximum value of S max , S min and S lowThey are respectively the maximum value, minimum value and preset intermediate value of the energy storage charge state S; a is the adaptive factor of the design coefficient, and its size can change the change of the coefficient. In the technical solution of the present application, a can take any value from 12 to 17, and the preferred value is 15.

[0183] When the energy storage S OC When the discharge coefficient of the energy storage is too high, set it to the maximum value so that the battery's S OC Slow down the speed of reaching the upper limit. Similarly, when the energy storage S OC When the battery is low, set the energy storage charging factor to the maximum value so that the battery S OC Able to recover faster, with S OC As the charging factor increases, it decreases. OC Divided into three areas, for example, you can set the lower limit S min is 0.1, the middle value S low is 0.5, the upper limit S max is 0.9. Among them, the lower limit S min The value range is 0.07 to 0.15; the intermediate value S low The value range is 0.45 to 0.618; the upper limit S max The value range is 0.83 to 0.91.

[0184] As a preferred solution, a parameter matching model can be trained using previous historical data. The parameter matching model is a neural network model, specifically, a convolutional neural network model.

[0185] The purpose of setting the parameter matching model is to set S according to the specific situation. max , S min , S low and a.

[0186] Δf s and Δf wind And the energy storage charge state S as input data, S max , S min , S low and a as output data to train the parameter matching model. Thus, a large amount of historical data is used to select the best training to dynamically output S max , S min , S low and a model, thereby greatly improving the accuracy of the control scheme.

[0187] That is, configure a parameter matching model so that Δf s and Δf wind and the energy storage charge state S as input data to make the parameter match the model dynamic output S max , S min, S low and a. The output frequency can be configured according to control needs.

[0188] As another preferred solution, as a further improvement, Δf s and Δf wind And the energy storage charge state S as input data, with K cn_disch and K cn_ch A coefficient matching model is trained as output data.

[0189] That is, configure a coefficient matching model so that Δf s and Δf wind and the energy storage charge state S as input data to make the coefficients match the model dynamic output Δf s and Δf wind The coefficient matching model can also be a convolutional neural network.

[0190] The technical solution of this application improves the frequency regulation capability and wind energy utilization rate of the wind storage system, gives full play to the characteristics of stable performance, flexible control and fast response of the energy storage system, and reduces the impact on the power grid caused by frequency changes. In addition, the rapid response characteristics of the battery energy storage system are used to convert the energy generated by the wind turbine into electrical energy, so that the wind turbine and energy storage can cooperate in the frequency regulation of the power grid.

[0191] This application takes into account the charging and discharging functions of energy storage, improves the utilization rate of energy storage, and makes the frequency deviation of the wind storage system lower and the frequency regulation time shorter after the first frequency regulation, thereby achieving the purpose of improving the frequency regulation effect and obtaining a higher wind energy utilization rate;

[0192] In order to solve the power mismatch problem caused by inconsistent adaptive droop coefficients when switching working conditions, the present application matches the adaptive droop coefficient of the wind turbine device with the adaptive droop coefficient of the energy storage device to obtain more accurate power instructions, avoid excessive energy storage to supplement the power shortage, and obtain better frequency recovery effect.

[0193] The adaptive droop coefficient proposed in the present application has a better recovery effect on the state of charge of the energy storage device, greatly improves the utilization rate of the energy storage device, and improves the frequency modulation effect.

[0194] Effect verification

[0195] Next, the frequency modulation effect of the present application is described with reference to experimental results.

[0196] The wind-storage system containing a wind turbine and an energy storage device can be used as the research object to verify the effect in MATLAB / Simulink. The total simulation time is set to 200s, and the relevant parameters are shown in Table 4.

[0197] Table 4 Simulation parameter settings

[0198]

[0199] The existing frequency regulation control method with a fixed energy storage droop coefficient (traditional wind-storage combined frequency regulation) is compared with the first frequency regulation control scheme and the second frequency regulation control scheme provided in this application.

[0200] like Fig.11 As shown, Fig.11 The system frequency changes of wind turbines participating in system frequency regulation under three different frequency regulation control methods are shown, and the corresponding average frequency deviation values ​​and average wind energy utilization coefficient values ​​are shown in Table 5.

[0201] Table 5 Average frequency deviation and average wind energy utilization factor

[0202] Control strategy Average frequency deviation / Hz Average wind energy utilization factor Fixed energy storage droop coefficient 0.011 0.4569 The first frequency modulation control scheme 0.0073 0.4587 The second frequency modulation control scheme 0.0025 0.4588

[0203] Reference Fig.11 As shown in Table 5, when the wind speed and load fluctuate randomly at the same time, the maximum fluctuation range of the frequency deviation of the fixed energy storage droop coefficient is -0.053Hz to 0.052Hz; the maximum fluctuation range of the frequency deviation of the first frequency modulation control scheme is -0.053Hz to 0.08Hz; the maximum fluctuation range of the frequency deviation of the second frequency modulation control scheme is -0.048Hz to 0.047Hz; it can be seen from Table 5 that the average frequency deviation of the second frequency modulation control scheme is the smallest, only 0.0025Hz, and the average wind energy utilization coefficient is the largest, which is 0.4588. Therefore, compared with the other two control schemes, the second frequency modulation control scheme has the best frequency regulation ability and the highest wind energy utilization rate.

[0204] like Fig.12 As shown, Fig.12 The energy storage output power under three different frequency modulation control methods is shown. Fig.12 It can be seen that the second frequency modulation control scheme enables the energy storage to charge during the period of 80-120s, which makes up for the defect of the energy storage not being charged in the first frequency modulation control scheme and fully utilizes the charging function of the energy storage. In addition, compared with the existing frequency modulation control method with a fixed energy storage droop coefficient, the second frequency modulation control scheme of the present application can enable the energy storage to provide more charging power during the period of 80-120s, thereby greatly improving the frequency deviation (compare Fig.11 frequency deviation of 80-120s).

[0205] like Fig.13 As shown, Fig.13 The wind turbine rotor speed and energy storage S under three different frequency control methods are shown. OC Changes in situation.

[0206] Reference Fig.13 As shown in (a), during the period of 80-120s, compared with the first frequency modulation control scheme provided in the present application, the second frequency modulation control scheme provided in the present application adopts energy storage charging for frequency modulation instead of using a fan for frequency modulation, so the rotor speed is closer to the optimal rotor speed.

[0207] Reference Fig.13 As shown in (b), the energy storage S of the existing frequency modulation control method with a fixed energy storage droop coefficient OC The average value is 0.478. The energy storage S of the first frequency modulation control solution provided in this application OC The average value of is 0.454, while the second frequency modulation control scheme energy storage S provided in this application OC The average value is 0.4819, the charge state of the energy storage is restored better, which greatly improves the utilization rate of the energy storage and the frequency regulation effect.

[0208] Reference Fig.14 As shown, during the period from 80 seconds to 120 seconds, the frequency deviation of the second frequency modulation control scheme provided by the present application is the smallest. During this period, the random change of wind speed is within the frequency modulation dead zone after frequency separation, and the load is reduced. The separated load frequency change amplifies the frequency modulation signal compared with the case of no separation, satisfies the switching rule of the first working condition, and switches to energy storage to participate in frequency modulation, such as Fig.12 The energy storage output power shown, while the first frequency modulation control scheme provided in this application switches to variable power point tracking control in this case, and the energy storage does not participate in the frequency modulation, so the frequency modulation effect is far inferior to the second frequency modulation control scheme provided in this application.

[0209] Reference Fig.15 As shown, as another aspect of the present application, the present application also provides a wind-storage combined primary frequency regulation control system that takes into account complex working conditions at the source end, including: a data module 100, a determination module 200, a power module 300, and an instruction module 400.

[0210] The data module 100 is used to obtain the wind speed data and load data of the wind storage system; the determination module 200 is used to determine the wind speed frequency deviation Δf according to the wind speed data. wind , and a load frequency deviation Δf determined according to the load data s After all of them have passed the dead zone, according to the wind speed frequency deviation Δf wind Determine the wind speed change power and the load frequency deviation Δf sDetermine the load change power; the power module 300 is used to determine the current preset operating condition and calculate the power required for frequency regulation based on the wind speed change power and the load change power; the instruction module 400 is used to generate a wind turbine droop control instruction or energy storage droop control instruction for realizing frequency regulation of the wind storage system based on the current preset operating condition and the power required for frequency regulation.

[0211] In some embodiments of the present application, the determination module 200 determines that when the wind speed frequency deviation Δf wind When the wind speed is less than a preset threshold, the wind speed change power is determined to be the wind speed reduction power P4 or / and the wind speed change power is determined to be the wind speed increase power P2;

[0212] The module 200 determines when the load frequency deviation Δf s When it is less than a preset threshold, the load change power is determined to be the load reduction power P1 or / and the load change power is determined to be the load increase power P3.

[0213] Optionally, in some embodiments of the present application, the power module 300 determines that the current preset operating condition is the first operating condition when the wind speed change power is the wind speed increase power P2 and the load change power is the load reduction power P1;

[0214] When the wind speed change power is the wind speed reduction power P4 and the load change power is the load reduction power P1, the power module 300 determines that the current preset operating condition is the second operating condition if the sum of the wind speed reduction power P4 and the load reduction power P1 is less than 0;

[0215] When the wind speed change power is the wind speed increase power P2 and the load change power is the load increase power P3, if the sum of the wind speed increase power P2 and the load increase power P3 is less than 0, the power module 300 determines that the current preset operating condition is the third operating condition;

[0216] When the sum of the wind speed reduction power P4 and the load reduction power P1 is greater than 0, the power module 300 determines that the current preset operating condition is the fourth operating condition;

[0217] When the sum of the wind speed increase power P2 and the load increase power P3 is greater than 0, the power module 300 determines that the current preset working condition is the fifth working condition;

[0218] When the wind speed change power is the wind speed reduction power P4 and the load change power is the load increase power P3, the power module 300 determines that the current preset operating condition is the sixth operating condition;

[0219] The first operating condition is used to indicate that the wind speed increases and the load decreases, the system needs to reduce power, and the energy storage device in the wind storage system performs frequency modulation;

[0220] The second operating condition is used to indicate that the wind speed decreases and the load decreases, the system cannot determine the power demand, and the wind turbine device in the wind storage system performs frequency modulation;

[0221] Among them, the third operating condition is used to indicate that the wind speed increases and the load increases, the system cannot determine the power demand, and the wind turbine device in the wind storage system performs frequency modulation;

[0222] Among them, the fourth operating condition is used to indicate that the wind speed decreases and the load decreases, the system cannot determine the power demand, and the energy storage device in the wind storage system performs frequency regulation;

[0223] Among them, the fifth operating condition is used to indicate that the wind speed increases and the load increases, the system cannot determine the power demand, and the energy storage device in the wind storage system performs frequency regulation;

[0224] Among them, the sixth operating condition is used to indicate that the wind speed decreases and the load increases, the system needs to increase power, and the energy storage device in the wind storage system performs frequency regulation.

[0225] Optionally, in some embodiments of the present application, the power module 300 calculates the power ΔP required for frequency modulation using the following formula:

[0226]

[0227] Among them, K cn is the adaptive droop coefficient of the energy storage device of the wind energy storage system, K p is the adaptive droop coefficient of the wind turbine device in the wind energy storage system, K cn With K p is the consistent adaptive droop coefficient;

[0228] K cn Including discharge coefficient K cn_disch or / and charging factor K cn_ch ;

[0229] Among them, the discharge coefficient K cn_disch The formula is as follows:

[0230]

[0231] Among them, the charging coefficient K cn_ch The formulas are as follows:

[0232]

[0233] Among them, K M K cn The maximum value of S max , S min and S loware respectively the maximum value, minimum value and preset intermediate value of the energy storage charge state S; a is the adaptive factor.

[0234] The above description is only some preferred embodiments of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the embodiments of the present application is not limited to the technical solutions formed by the specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above invention concept. For example, the above features are replaced with (but not limited to) the technical features with similar functions disclosed in the embodiments of the present application to form a technical solution.

Claims

1. A wind-storage combined primary frequency modulation control method considering complex working conditions at the source end, characterized in that: The wind-storage combined primary frequency modulation control method considering complex working conditions at the source end includes: S100: Acquire wind speed data and load data of the wind storage system; S200: determining a wind speed frequency deviation Δf according to the wind speed data wind , and a load frequency deviation Δf determined according to the load data s After all of them have passed the dead zone, according to the wind speed frequency deviation Δf wind Determine the wind speed change power and the load frequency deviation Δf s Determine load change power; S300: Determine the current preset working condition and calculate the power required for frequency regulation according to the wind speed variation power and the load variation power; S400: Generate a wind turbine droop control instruction or an energy storage droop control instruction for realizing frequency regulation of the wind-storage system according to the current preset operating condition and the power required for the frequency regulation.

2. The wind-storage combined primary frequency modulation control method considering complex source conditions according to claim 1 is characterized in that: The step S200 includes: When the wind speed frequency deviation Δf wind When it is less than a preset threshold, the wind speed change power is determined to be the wind speed reduction power P4; When the wind speed frequency deviation Δf wind When it is greater than a preset threshold, the wind speed change power is determined to be the wind speed increase power P2; When the load frequency deviation Δf s When it is less than a preset threshold, the load change power is determined to be the load reduction power P1; When the load frequency deviation Δf s When it is greater than a preset threshold, the load change power is determined to be the load increase power P3.

3. The wind-storage combined primary frequency modulation control method considering complex source conditions according to claim 1 or 2 is characterized in that: The preset working conditions in step S300 include: When the wind speed change power is the wind speed increase power P2, and the load change power is the load reduction power P1, determining that the current preset operating condition is the first operating condition; When the wind speed change power is the wind speed reduction power P4, and the load change power is the load reduction power P1, if the sum of the wind speed reduction power P4 and the load reduction power P1 is less than 0, it is determined that the current preset operating condition is the second operating condition; When the wind speed change power is the wind speed increase power P2, and the load change power is the load increase power P3, if the sum of the wind speed increase power P2 and the load increase power P3 is less than 0, it is determined that the current preset operating condition is the third operating condition; When the sum of the wind speed reduction power P4 and the load reduction power P1 is greater than 0, it is determined that the current preset operating condition is the fourth operating condition; When the sum of the wind speed increase power P2 and the load increase power P3 is greater than 0, it is determined that the current preset working condition is the fifth working condition; When the wind speed change power is the wind speed reduction power P4, and the load change power is the load increase power P3, it is determined that the current preset operating condition is the sixth operating condition.

4. The wind-storage combined primary frequency modulation control method considering complex source conditions according to claim 3 is characterized in that: The preset working conditions include: The first operating condition is used to indicate that the wind speed increases and the load decreases, the system needs to reduce power, and the wind turbine device in the wind storage system performs frequency modulation, or the energy storage device in the wind storage system performs frequency modulation; The second operating condition is used to indicate that the wind speed decreases and the load decreases, the system cannot determine the power demand, and the wind turbine device in the wind storage system performs frequency modulation; The third operating condition is used to indicate that the wind speed increases and the load increases, the system cannot determine the power demand, and the wind turbine device in the wind storage system performs frequency modulation; The fourth operating condition is used to indicate that the wind speed decreases and the load decreases, the system cannot determine the power demand, and the energy storage device in the wind storage system performs frequency modulation; The fifth operating condition is used to indicate that the wind speed increases and the load increases, the system cannot determine the power demand, and the energy storage device in the wind storage system performs frequency modulation; The sixth operating condition is used to indicate that the wind speed decreases and the load increases, the system needs to increase power, and the energy storage device in the wind storage system performs frequency modulation.

5. The wind-storage combined primary frequency modulation control method considering complex source conditions according to claim 1 is characterized in that: The formula for the power ΔP required for frequency modulation is as follows: Among them, K cn is the adaptive droop coefficient of the energy storage device of the wind energy storage system, K p is the adaptive droop coefficient of the wind turbine device of the wind storage system, and the K cn With the K p is the consistent adaptive droop coefficient.

6. The wind-storage combined primary frequency modulation control method considering complex source conditions according to claim 5 is characterized in that: The adaptive droop coefficient K of the energy storage device of the wind storage system cn Including discharge coefficient K cn_disch or / and charging factor K cn_ch ; Among them, the discharge coefficient K cn_disch The formula is as follows: Among them, the charging coefficient K cn_ch The formulas are as follows: Among them, K M K cn The maximum value of S max , S min and S low are respectively the maximum value, minimum value and preset intermediate value of the energy storage charge state S; a is the adaptive factor.

7. A wind-storage combined primary frequency modulation control system considering complex working conditions at the source end, characterized in that: include: Data module, used to obtain wind speed data and load data of wind storage system; A determination module is used to determine the wind speed frequency deviation Δf according to the wind speed data. wind , and a load frequency deviation Δf determined according to the load data s After all of them have passed the dead zone, according to the wind speed frequency deviation Δf wind Determine the wind speed change power and the load frequency deviation Δf s Determine load change power; A power module, used to determine the current preset working condition and calculate the power required for frequency regulation according to the wind speed change power and the load change power; The instruction module is used to generate a wind turbine droop control instruction or an energy storage droop control instruction for realizing frequency regulation of the wind-storage system according to the current preset working condition and the power required for the frequency regulation.

8. The wind-storage combined primary frequency modulation control system considering complex source conditions according to claim 7 is characterized in that: The determination module determines the wind speed frequency deviation Δf wind When the wind speed is less than a preset threshold, the wind speed change power is determined to be the wind speed reduction power P4 or / and the wind speed change power is determined to be the wind speed increase power P2; The determination module determines the load frequency deviation Δf s When it is less than a preset threshold, the load change power is determined to be the load reduction power P1 or / and the load change power is determined to be the load increase power P3.

9. The wind-storage combined primary frequency modulation control system considering complex source conditions according to claim 7 is characterized in that: The power module determines that the current preset operating condition is the first operating condition when the wind speed change power is the wind speed increase power P2 and the load change power is the load reduction power P1; The power module determines that the current preset operating condition is the second operating condition when the wind speed change power is the wind speed reduction power P4 and the load change power is the load reduction power P1 and if the sum of the wind speed reduction power P4 and the load reduction power P1 is less than 0; The power module determines that the current preset operating condition is the third operating condition when the wind speed change power is the wind speed increase power P2 and the load change power is the load increase power P3 and if the sum of the wind speed increase power P2 and the load increase power P3 is less than 0; When the sum of the wind speed reduction power P4 and the load reduction power P1 is greater than 0, the power module determines that the current preset operating condition is the fourth operating condition; When the sum of the wind speed increase power P2 and the load increase power P3 is greater than 0, the power module determines that the current preset working condition is the fifth working condition; The power module determines that the current preset operating condition is the sixth operating condition when the wind speed change power is the wind speed reduction power P4 and the load change power is the load increase power P3; The first operating condition is used to indicate that the wind speed increases and the load decreases, the system needs to reduce power, and the wind turbine device in the wind storage system performs frequency modulation, or the energy storage device in the wind storage system performs frequency modulation; The second operating condition is used to indicate that the wind speed decreases and the load decreases, the system cannot determine the power demand, and the wind turbine device in the wind storage system performs frequency modulation; The third operating condition is used to indicate that the wind speed increases and the load increases, the system cannot determine the power demand, and the wind turbine device in the wind storage system performs frequency modulation; The fourth operating condition is used to indicate that the wind speed decreases and the load decreases, the system cannot determine the power demand, and the energy storage device in the wind storage system performs frequency modulation; The fifth operating condition is used to indicate that the wind speed increases and the load increases, the system cannot determine the power demand, and the energy storage device in the wind storage system performs frequency modulation; Among them, the sixth operating condition is used to indicate that the wind speed decreases and the load increases, the system needs to increase power, and the energy storage device in the wind storage system performs frequency modulation.

10. The wind-storage combined primary frequency modulation control system considering complex source conditions according to claim 7 is characterized in that: The formula for the power module to calculate the power ΔP required for the frequency modulation is as follows: Among them, K cn is the adaptive droop coefficient of the energy storage device of the wind energy storage system, K p is the adaptive droop coefficient of the wind turbine device of the wind storage system, and the K cn With the K p is the consistent adaptive droop coefficient; The adaptive droop coefficient K of the energy storage device of the wind storage system cn Including discharge coefficient K cn_disch or / and charging factor K cn_ch ; Among them, the discharge coefficient K cn_disch The formula is as follows: Among them, the charging coefficient K cn_ch The formulas are as follows: Among them, K M K cn The maximum value of S max , S min and S low are respectively the maximum value, minimum value and preset intermediate value of the energy storage charge state S; a is the adaptive factor.

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