Power reduction control method and device for wind power plant, controller and storage medium

Abstract

The invention provides a power reduction control method and device for a wind power plant, a controller and a storage medium. The power reduction control method for the wind power plant comprises the following steps: responding to a condition that the frequency of a grid-connected point is greater than an over-frequency threshold parameter, and determining a full-field power reduction amount needing wind power plant adjustment based on an adjustment amount parameter; calculating inertia adjustment time required for completing the full-field power reduction amount by adopting inertia response; responding to the condition that the inertia adjustment time is smaller than or equal to an adjustment time parameter, and controlling a fan in the wind power plant to reduce power in a non-braking resistance power reduction mode; wherein an over-frequency threshold parameter for defining a lower limit value of the severe over-frequency range, an adjustment variable parameter for defining an adjustment variable requirement for the rapid power reduction, and an adjustment time parameter for defining an adjustment time requirement for the rapid power reduction are preset.

Description

Technical Field

[0001] The present disclosure generally relates to the field of wind power technology, and more specifically, to a power reduction control method, device, controller and storage medium for a wind farm. Background Art

[0002] Figure 1 An example of wind farm regulating active power in response to grid frequency is shown. Figure 1 As shown, Fn represents the rated frequency of the power grid, P0 represents the full-field power value, and Pn represents the full-field rated power value. When the frequency of the grid connection point is in [Fd-~Fd+] (i.e., the dead zone range of the primary frequency modulation), the wind turbines in the wind farm (hereinafter referred to as wind turbines) receive the active power instructions of the energy management system (EMS) of the wind farm. When the frequency of the grid connection point is in [F3~Fd-] or [Fd+~F1], the wind turbines can be controlled to use primary frequency modulation to adjust the active power. For example, when the frequency of the grid connection point is in [Fd+~F1], the full-field active frequency modulation amplitude can be 10% Pn, and the response time can be 3s. When the frequency of the grid connection point is in [F1~F2], the power grid is in a serious overfrequency state, and the wind farm needs to adopt a fast power reduction control strategy. For example, the full-field active frequency modulation amplitude can be 50% Pn, and the adjustment time can be 3s. When the frequency of the grid-connected point is greater than F2, the active power remains unchanged at the current state, and further changes in frequency require further reduction of power.

[0003] When the frequency of the grid connection point deviates from the rated frequency of the grid, the wind farm needs to adjust the active power output. The grids in different countries / regions have different requirements for this, especially when the frequency of the grid connection point is seriously overfrequency. For example, some countries / regions require that the power reduction speed be fast when the frequency is seriously overfrequency, and the wind farm needs to reduce 50% Pn within 2s; some countries / regions require that the wind farm reduce 50% Pn within 5s when the frequency is seriously overfrequency.

[0004] The existing method of rapid power reduction in case of severe overfrequency, on the one hand, needs to be designed in accordance with the grid requirements of specific countries / regions and has poor versatility; on the other hand, it has a certain impact on the reliability, safety and stability of wind farms. Summary of the invention

[0005] An exemplary embodiment of the present disclosure provides a method, device, controller and storage medium for controlling power reduction of a wind farm, which can effectively solve the above-mentioned problems existing in the prior art.

[0006] According to a first aspect of an embodiment of the present disclosure, a power reduction control method for a wind farm is provided, comprising: in response to a frequency of a grid-connected point being greater than an overfrequency threshold parameter, determining a power reduction amount for the entire wind farm that needs to be adjusted based on an adjustment amount parameter; calculating an inertia adjustment time required to complete the power reduction amount for the entire wind farm using an inertia response; in response to the inertia adjustment time being less than or equal to an adjustment time parameter, controlling wind turbines in the wind farm to reduce power using a non-braking resistor power reduction method; wherein an overfrequency threshold parameter for limiting a lower limit value of a severe overfrequency range, an adjustment amount parameter for limiting an adjustment amount requirement for rapid power reduction, and an adjustment time parameter for limiting an adjustment time requirement for rapid power reduction are pre-set.

[0007] Optionally, it also includes: in response to the inertia adjustment time being greater than the adjustment time parameter, calculating the braking resistor activation amount required to complete the full-field power reduction amount using the inertia response and the braking resistor; in response to the braking resistor activation amount being greater than a preset threshold, controlling the wind turbine to reduce power using the braking resistor; in response to the braking resistor activation amount being less than or equal to the preset threshold, controlling the field-level centralized energy storage system or the wind turbine energy storage system to reduce power instead of the braking resistor.

[0008] Optionally, the step of controlling the fan to reduce power by using a braking resistor includes: in a first stage, controlling the fan to reduce power by using a non-braking resistor power reduction method, and then in a second stage, controlling the fan to reduce power by using both a non-braking resistor power reduction method and a braking resistor.

[0009] Optionally, compared with the first stage, the target regulation rate of limiting the grid-side power output of the wind turbine in the second stage is higher.

[0010] Optionally, compared with the first stage, the target regulation rate of the non-braking resistance power reduction mode of the fan in the second stage is lower.

[0011] Optionally, the step of controlling the wind turbines to simultaneously use a non-braking resistor power reduction method and a braking resistor to reduce power in the second stage includes: determining a remaining power reduction amount that needs to be adjusted in the second stage based on the total power reduction amount and the real-time value of the total power at the end of the first stage; determining a single-machine power reduction amount that needs to be adjusted for each wind turbine in the second stage based on the remaining power reduction amount; and determining a target adjustment rate for limiting the power output of the grid side of each wind turbine in the second stage based on the adjustment time parameter, the adjustment time of the first stage, the single-machine power reduction amount of each wind turbine, and the control coefficient.

[0012] Optionally, the step of controlling the wind turbines in the wind farm to reduce power by adopting a non-braking resistor power reduction method includes: controlling the wind turbines to reduce power by adopting at least one of inertia response, primary frequency modulation, and a wind turbine energy storage system.

[0013] Optionally, the step of controlling the wind turbine to reduce power by using at least one of inertia response, primary frequency modulation, and a wind turbine energy storage system includes: controlling the wind turbine to reduce power only by using inertia response; or controlling the wind turbine to first reduce power by using inertia response, and then using primary frequency modulation to reduce power; or controlling the wind turbine to first reduce power by using primary frequency modulation, and then using inertia response to reduce power; or controlling the wind turbine to reduce power by using inertia response, and controlling a field-level centralized energy storage system to reduce power; or controlling the wind turbine to reduce power by using inertia response and a wind turbine energy storage system.

[0014] Optionally, the steps of controlling the wind turbines to reduce power by inertia response and controlling the field-level centralized energy storage system to reduce power include: determining the reducible power amount of the field-level centralized energy storage system and the inertia reducible power amount of each wind turbine; in accordance with the principle of making full use of the reducible power amount of the field-level centralized energy storage system, based on the total field power reduction amount, the reducible power amount of the field-level centralized energy storage system and the inertia reducible power amount of each wind turbine, simultaneously controlling the field-level centralized energy storage system to reduce power and each wind turbine to reduce power by inertia response.

[0015] Optionally, the step of controlling the wind turbines to reduce power by using inertia response and wind turbine energy storage systems includes: determining the inertia-reducible power amount of each wind turbine and the inertia-reducible power amount of the wind turbine energy storage system, and in accordance with the principle of making full use of the reducible power amount of the wind turbine energy storage system, based on the total power reduction amount, the inertia-reducible power amount of each wind turbine and the reducible power amount of the wind turbine energy storage system, controlling each wind turbine to simultaneously use inertia response and the wind turbine energy storage system to reduce power; or, based on the single-machine power reduction amount that needs to be adjusted by each wind turbine, issuing power adjustment instructions to each wind turbine respectively, so that each wind turbine simultaneously uses inertia response and the wind turbine energy storage system to reduce power according to the received power adjustment instructions.

[0016] According to a second aspect of an embodiment of the present disclosure, a power reduction control device for a wind farm is provided, comprising: an adjustment amount determination unit, configured to determine, in response to a frequency of a grid-connected point being greater than an overfrequency threshold parameter, a full-field power reduction amount that needs to be adjusted by the wind farm based on the adjustment amount parameter; an inertia adjustment time determination unit, configured to calculate an inertia adjustment time required to complete the full-field power reduction amount using an inertia response; a wind turbine control unit, configured to reduce power using a non-braking resistor for wind turbines in the wind farm in response to the inertia adjustment time being less than or equal to an adjustment time parameter; wherein an overfrequency threshold parameter for limiting a lower limit value of a severe overfrequency range, an adjustment amount parameter for limiting an adjustment amount requirement for rapid power reduction, and an adjustment time parameter for limiting an adjustment time requirement for rapid power reduction are preset.

[0017] According to a third aspect of an embodiment of the present disclosure, a computer-readable storage medium storing a computer program is provided. When the computer program is executed by a processor, the processor is prompted to execute the power reduction control method for a wind farm as described above.

[0018] According to a fourth aspect of an embodiment of the present disclosure, a controller of a wind farm is provided, comprising: a processor; and a memory storing a computer program, which, when executed by the processor, prompts the processor to execute the power reduction control method of the wind farm as described above.

[0019] According to a fifth aspect of an embodiment of the present disclosure, there is provided a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the power reduction control method for a wind farm as described above is implemented.

[0020] According to the power reduction control method, device, controller, storage medium and program product of the wind farm of the exemplary embodiment of the present disclosure, on the one hand, the severe overfrequency rapid power reduction scheme is parameterized by setting multiple parameters that can be pre-set, so that the same scheme can be applied to countries / regions with different requirements for severe overfrequency rapid power reduction, thereby improving the applicability of the scheme; on the other hand, it is proposed not to enable the braking resistor unless necessary in the severe overfrequency rapid power reduction control, so as to minimize the response effects of severe overfrequency rapid power reduction and low voltage ride-through LVRT, and improve the safety and stability of wind turbine operation.

[0021] In the following description, some aspects and / or advantages of the general inventive concept will be set forth, and some other aspects and / or advantages will be known through the following description or the implementation of the general inventive concept. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] These and / or other aspects and advantages of the present application will become clearer and easier to understand from the following detailed description of the embodiments of the present application in conjunction with the accompanying drawings, in which:

[0023] Figure 1 An example showing an existing wind farm regulating power in response to grid frequency;

[0024] Figure 2 A flow chart showing a power reduction control method of a wind farm according to an exemplary embodiment of the present disclosure;

[0025] Figure 3 A flow chart showing a power reduction control method of a wind farm according to another exemplary embodiment of the present disclosure;

[0026] Figure 4 A flow chart showing a method for controlling a wind turbine to reduce power by simultaneously using a non-braking resistor power reduction method and a braking resistor in a second stage according to an exemplary embodiment of the present disclosure;

[0027] Figure 5 An example of an existing rapid power reduction curve for a wind turbine in the event of severe overfrequency is shown;

[0028] Figure 6 An example of a wind turbine rapid power reduction curve when a severe overfrequency condition occurs according to an exemplary embodiment of the present disclosure is shown;

[0029] Figure 7 Another example of a wind turbine rapid power reduction curve when a severe overfrequency condition occurs according to an exemplary embodiment of the present disclosure is shown;

[0030] Figure 8 A flow chart showing a method for reducing power using inertial response and a field-level centralized energy storage system according to an exemplary embodiment of the present disclosure;

[0031] Fig. 9 A flow chart showing a method for reducing power using inertial response and a distributed energy storage system according to an exemplary embodiment of the present disclosure;

[0032] Fig.10 A flow chart showing a method for reducing power using inertia response and a distributed energy storage system according to another exemplary embodiment of the present disclosure;

[0033] Fig.11 A flow chart showing a method for reducing power using inertia response and a distributed energy storage system according to another exemplary embodiment of the present disclosure;

[0034] Fig.12 A structural block diagram of a wind farm power reduction control device according to an exemplary embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0035] Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like parts throughout. The embodiments will be described below with reference to the drawings in order to explain the present disclosure.

[0036] It should be noted that the terms "first", "second", etc. in the specification and claims of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present disclosure described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0037] It should be noted that the phrase "at least one of the items" in the present disclosure includes three types of parallel situations: "any one of the items", "a combination of any number of the items", and "all of the items". For example, "including at least one of A and B" includes the following three parallel situations: (1) including A; (2) including B; (3) including A and B. Another example is "executing at least one of step 1 and step 2" which means the following three parallel situations: (1) executing step 1; (2) executing step 2; (3) executing step 1 and step 2.

[0038] Rapid power reduction of a wind turbine (for example, reducing Pn by 50% within 2 seconds) is an extremely demanding operation that requires rapid and accurate adjustment of the wind turbine's operating state. The following are possible resources and methods for achieving rapid power reduction:

[0039] Pitch control: It is one of the most commonly used power regulation methods in wind turbines. By quickly adjusting the pitch angle of the blades, the efficiency of the blades in capturing wind energy can be changed, thereby achieving rapid power reduction. In the case of rapid power reduction, the pitch control system needs to respond quickly and accurately adjust the pitch angle to the predetermined position.

[0040] Braking resistor: When the wind turbine needs to reduce power quickly, the excess power can be consumed by using a braking resistor, thereby achieving the purpose of reducing power. This method is suitable for situations where a large amount of power needs to be consumed in a short period of time. For example, a direct-drive wind turbine can be braked using a Chopper device, and a doubly-fed wind turbine can be braked using a Crowbar circuit.

[0041] Generator control: The output power of the generator can be changed by adjusting the excitation current or speed of the generator. In the case of rapid power reduction, the generator control system needs to quickly adjust parameters to ensure accurate power reduction.

[0042] Yaw control: Although yaw control is mainly used to keep the wind turbine perpendicular to the wind direction to maximize wind energy capture efficiency, in some cases, yaw control can also be used to assist in achieving rapid power reduction. That is, by adjusting the yaw angle of the wind turbine, the energy captured by the wind can be reduced, thereby reducing the wind turbine output power. In the case of rapid power reduction, the effect of this method may be relatively limited and needs to be used in combination with other control methods.

[0043] The following will introduce inertia control. Inertia is an important parameter of the power system, which reflects the system's ability to resist rapid frequency changes. The inertia control of the wind turbine aims to adjust the operating state of the wind turbine so that it can provide inertial support for system frequency changes like a traditional synchronous generator. The inertia control strategy of the wind turbine can be divided into current source control and voltage source control. Current source control: With the output current as the control target, the active output of the wind turbine is changed by introducing virtual inertia and droop control; Voltage source control: Unlike current source control, it focuses on achieving inertia control by adjusting the voltage output of the wind turbine.

[0044] In the inertia control of wind turbines, adjusting the excitation current and speed of the generator is a possible control method, but not the only one. For doubly fed wind turbines, the control is more complicated because it has the operating characteristics of both asynchronous motors and synchronous motors. The inertia control of doubly fed wind turbines may involve the coordinated control of the rotor-side converter and the grid-side converter to adjust the excitation current and speed. For direct-drive permanent magnet synchronous wind turbines, inertia control may rely more on the control strategy of the converter, and possible assistance from the energy storage system. Therefore, in addition to adjusting the excitation current and speed, the inertia control of wind turbines may also involve the use of energy storage systems, pitch angle control, and overspeed-load reduction operation strategies. The energy storage system can provide or absorb energy in a short period of time, thereby helping the wind turbine to respond quickly to changes in system frequency.

[0045] In summary, the inertia control of the fan is not limited to controlling the excitation current or speed of the generator. It is a comprehensive control strategy that may involve the combined use of multiple control means and technologies to achieve a fast and effective response of the fan to system frequency changes.

[0046] Chopper devices are usually designed for use in wind power converters to deal with grid low voltage ride-through faults. When the grid voltage drops, the grid voltage at the grid connection point decreases, resulting in obstruction of wind turbine energy delivery. At this time, the Chopper device discharges energy through the IGBT power module in series with the energy discharge resistor to protect the wind power converter and achieve low voltage ride-through function. The action of the Chopper device is instantaneous. Once the DC bus voltage exceeds the set value, it will immediately start to discharge energy, so its energy discharge speed is very fast.

[0047] Electrochemical energy storage systems, such as lithium-ion batteries or supercapacitors, store and release energy through chemical reactions. These systems generally have high energy and power density and are able to respond quickly to grid demand to provide or absorb energy. However, compared with the instantaneous energy discharge of Chopper devices, the energy discharge rate of electrochemical energy storage systems may be affected by factors such as the internal chemical reaction rate of the battery, the control strategy of the battery management system (BMS), and external circuit limitations. From the perspective of instantaneous energy discharge, Chopper devices generally have faster energy discharge rates due to their mechanism of directly discharging energy through resistance. Although electrochemical energy storage systems are also able to respond quickly and provide or absorb energy, their discharge speed may be affected by more factors and may not be as fast as Chopper devices in some cases.

[0048] The application of Crowbar circuit in wind turbine is mainly to protect the wind turbine from abnormal conditions such as grid voltage sag. Its working principle is to bypass the rotor current through the Crowbar resistor by short-circuiting the rotor side of the generator, thereby avoiding damage to the wind turbine caused by overcurrent. The original design of the Crowbar circuit is not for precise control of power reduction, but as a protection device. When the grid voltage is abnormal, the Crowbar circuit can act quickly to bypass the rotor current and protect the wind turbine from damage. It may be difficult to achieve the requirement of accurately reducing 50% power using the Crowbar circuit for power control because its main purpose is protection rather than precise control. The Crowbar circuit is usually triggered based on the grid voltage rather than directly used to control the wind turbine power output. The response time of the Crowbar circuit is usually very fast and can act within milliseconds, which is beneficial for achieving power reduction in a short time (for example, within 2 seconds). However, the accuracy and stability of power reduction may be limited.

[0049] The existing rapid power reduction scheme for wind farms with severe overfrequency at the grid connection point has the following shortcomings: 1) The specific rapid power reduction scheme can only be set up according to the specific requirements of the country / region where it is applied (for example, reducing 50% Pn within 3s), and the scheme cannot be applied to countries / regions with different severe overfrequency rapid power reduction requirements (for example, reducing 50% Pn within 2s). 2) Severe overfrequency rapid power reduction and low voltage ride-through LVRT affect each other. If the two operating conditions occur continuously in time, the post-triggering function will not respond normally and cannot meet the reliability requirements of the grid demand function. 3) If an overly large braking resistor is installed (for example, a Chopper device or a Crowbar circuit), it will increase costs and the installation size will be too large, and it may be necessary to change the internal installation structure of the wind turbine.

[0050] Taking the above-mentioned deficiencies into consideration, the present disclosure proposes, on one hand, that: by setting a plurality of pre-set parameters, the severe overfrequency rapid power reduction scheme is parameterized, so that the same scheme can be applicable to a variety of regulation performance requirements (regulation amount requirements, regulation time requirements, severe overfrequency range requirements), so that it can be applied to countries / regions with different requirements for severe overfrequency rapid power reduction, thereby increasing the scope of application. The present disclosure proposes, on the other hand, that: in severe overfrequency rapid power reduction, braking resistors should not be enabled unless necessary, so as to improve the reliability of the grid demand function, and minimize the response effects of severe overfrequency rapid power reduction and low voltage ride-through LVRT; improve the safety and stability of wind turbine operation, avoid the risk of excessive bus voltage and excessive current due to insufficient braking resistors, and try to make the wind turbine respond according to the active power control strategy of relatively slow speed as much as possible, so as to improve the safety factor and stability, and increase the life of the wind turbine; avoid unstable wind turbine operation caused by frequent use of braking resistors, so as to reduce maintenance costs and downtime. The following will be combined with Figures 2 to 12 Provide detailed explanation.

[0051] Figure 2 A flow chart showing a power reduction control method of a wind farm according to an exemplary embodiment of the present disclosure is shown.

[0052] As an example, the power reduction control method of a wind farm according to an exemplary embodiment of the present disclosure may be executed by a farm-level controller of the wind farm.The wind farm may include a plurality of wind turbines, which are connected to a power grid in an appropriate manner.

[0053] Reference Figure 2 In step S100, in response to the frequency of the grid connection point being greater than an overfrequency threshold parameter, a total power reduction amount that needs to be adjusted by the wind farm is determined based on an adjustment amount parameter.

[0054] Overfrequency threshold parameter f fast The lower limit value used to limit the severe overfrequency range can be preset according to the actual situation and specific needs. If the frequency of the grid connection point is greater than the overfrequency threshold parameter, it can be determined that the power grid is severely overfrequency.

[0055] The adjustment amount parameter δ% is used to limit the adjustment amount requirement for rapid power reduction, and can be preset according to actual conditions and specific needs.

[0056] As an exemplary embodiment, the step of determining the total power reduction amount that needs to be adjusted by the wind farm based on the adjustment amount parameter may include: taking the product of the adjustment amount parameter and the rated power Pn of the wind farm, or the product of the adjustment amount parameter and the current real-time power P0 of the wind farm as the total power reduction amount that needs to be reduced by the wind farm, specifically, the total power reduction amount DeltP = δ% × P n Or DeltP = δ% × P0.

[0057] As an exemplary embodiment, a reference parameter Base may also be included. The reference parameter is used to determine whether the total power reduction is calculated based on the rated power Pn or the current real-time power P0 in the above calculation, and may be pre-set according to actual conditions and specific needs.

[0058] In step S200, the inertia adjustment time required to complete the full-field power reduction using the inertia response is calculated.

[0059] As an exemplary embodiment, the inertia adjustment time Among them, Rate Iner Indicates the adjustment rate of the inertia response, for example, it can be 15% Pn 单机 / s~20%Pn 单机 / s.

[0060] In step S300, in response to the inertia adjustment time being less than or equal to the adjustment time parameter, the wind turbines in the wind farm are controlled to reduce power by using a non-braking resistor power reduction method. In other words, in response to the inertia adjustment time being less than or equal to the adjustment time parameter, the wind turbines are not controlled to enable the braking resistor to reduce power.

[0061] The adjustment time parameter N is used to limit the adjustment time requirement for rapid power reduction, and can be preset according to actual conditions and specific needs.

[0062] It should be understood that the overfrequency threshold parameter f may be set in advance according to the specific requirements of the country / region where the wind farm is located for rapid power reduction due to severe overfrequency. fast , adjustment amount parameter δ%, adjustment time parameter N, and reference parameter Base are specifically set, so that the power reduction control method of the wind farm according to the exemplary embodiment of the present disclosure can cover different rapid power reduction requirements. For example, for the requirement of reducing 50% Pn within 2 seconds, the adjustment amount parameter δ% needs to be set to 50%, the adjustment time parameter N is set to 2 seconds, and the reference parameter Base is set to Pn; for the requirement of reducing 60% P0 within 6 seconds, the adjustment amount parameter δ% needs to be set to 60%, the adjustment time parameter N is set to 6 seconds, and the reference parameter Base is set to P0.

[0063] As an exemplary embodiment, step S300 may include: in response to the inertia adjustment time being less than or equal to the adjustment time parameter, controlling the wind turbine to reduce power by using at least one of inertia response, primary frequency modulation, and a wind turbine energy storage system.

[0064] Preferably, the first to fifth embodiments are provided below for controlling the wind turbine to reduce power by using at least one of inertia response, primary frequency modulation, and a wind turbine energy storage system.

[0065] As a first embodiment, the wind turbines may be controlled to reduce power only by inertia response, that is, the power reduction of the entire field is completed entirely according to the inertia response.

[0066] As an example, if the inertia adjustment time is theoretically much more abundant than the adjustment time parameter, for the sake of simplicity, all inertia can be enabled. For example, for the adjustment requirement of reducing 60% Pn within 6s, if all Pn is reduced by 60% in 3s according to the inertia response, the requirement can be quickly met, and the consumption of brake resistors can be abandoned. In addition, for the adjustment requirement of reducing 50% Pn within 3s, if all Pn is reduced by 50% in 2.5s according to the inertia response, the requirement can also be met, and the consumption of brake resistors can be completely abandoned.

[0067] As a second embodiment, the fan may be controlled to first use inertia response to reduce power, and then use primary frequency modulation to reduce power. That is, the fan is controlled to first adjust the inertia response, and then perform primary frequency modulation.

[0068] For example, to meet the regulation requirement of reducing Pn by 60% within 6 seconds, the inertia response can be used to reduce Pn by 40% in the first 2 seconds, and the remaining 20% ​​Pn can be reduced by a single frequency modulation, which can also meet the requirement and completely avoid the consumption of braking resistors.

[0069] As a third embodiment, the fan may be controlled to firstly use a frequency modulation to reduce power, and then use an inertia response to reduce power. That is, the fan may be controlled to firstly use a frequency modulation, and then use an inertia response.

[0070] For example, to meet the regulation requirement of reducing Pn by 60% within 6s, a command can be issued to the fan to reduce Pn by 20% according to a frequency modulation. After the theoretical execution time of a frequency modulation is reached, the remaining 40% Pn is adjusted using inertia response, which can meet the demand and completely avoid the consumption of braking resistance.

[0071] Through resource analysis, if there are energy storage resources available, wind power + energy storage can also be used to achieve rapid power reduction. The conventional energy storage configuration of a wind farm is generally 10% to 15% Pn. When the SOC meets the regulation requirements, it can adjust up to 10% to 15% Pn in no more than 1s.

[0072] As a fourth embodiment, the wind turbine may be controlled to reduce power by adopting inertia response, and the field-level centralized energy storage system may be controlled to reduce power.

[0073] As an example, the steps of controlling the wind turbine to reduce power by inertia response and controlling the field-level centralized energy storage system to reduce power include: determining the reducible power amount of the field-level centralized energy storage system and the inertia reducible power amount of each wind turbine; in accordance with the principle of making full use of the reducible power amount of the field-level centralized energy storage system, based on the total field power reduction amount, the reducible power amount of the field-level centralized energy storage system and the inertia reducible power amount of each wind turbine, simultaneously controlling the field-level centralized energy storage system to reduce power and each wind turbine to reduce power by inertia response.

[0074] As an example, Figure 8 As shown, centralized energy storage (i.e., field-level centralized energy storage system) can be uniformly dispatched and managed by the field-level controller. The field controller can calculate based on the actual adjustable capacity of the wind turbine inertia and the adjustable capacity of the centralized energy storage under the current SOC state, and then divide the total regulation demand (i.e., DeltP) into two parts according to the calculation result. Usually, when the adjustment amount of the inertia response is between 20% and 30% of Pn, the regulation accuracy is high. However, if the adjustment amount of the inertia response is made larger, the accuracy and time accuracy will be reduced. Therefore, the allocation principle can be set as follows: try to use all the adjustable energy of the centralized energy storage, and allocate the rest to the inertia response. The two actions of inertia response power reduction and centralized energy storage power reduction can be performed simultaneously.

[0075] The mode flag G_DeltPFlag=1 indicates that the single frequency modulation power up mode is enabled (the mode and the execution rate match, and there is a matching rate setting channel), G_DeltPFlag=-1 indicates that the single frequency modulation power down mode is enabled (the mode and the execution rate match, and there is a matching rate setting channel), G_DeltPFlag=2 indicates that the fast power up mode is enabled (the mode and the execution rate match, and there is a matching rate setting channel), G_DeltPFlag=-2 indicates that the fast power down mode is enabled (the mode and the execution rate match, and there is a matching rate setting channel), G_DeltPFlag=3 indicates that the inertia response power up mode is enabled (the mode and the execution rate match, and there is a matching rate setting channel), G_DeltPFlag=-3 indicates that the inertia response power down mode is enabled (the mode and the execution rate match, and there is a matching rate setting channel). As an example, in an exemplary embodiment of the present disclosure, the mode flag G_DeltPFlag=-2 may be set.

[0076] As a fifth embodiment, the wind turbine may be controlled to reduce power by using inertia response and a wind turbine energy storage system.

[0077] As an example, the energy storage system of the wind turbine (for example, a grid-type wind turbine) can be directly controlled by the field control, and the step of controlling the wind turbine to reduce power by using inertia response and the wind turbine energy storage system may include: determining the inertia-reducible power amount of each wind turbine and the inertia-reducible power amount of the wind turbine energy storage system, and in accordance with the principle of making full use of the inertia-reducible power amount of the wind turbine energy storage system, based on the power reduction amount of the entire field, the inertia-reducible power amount of each wind turbine, and the inertia-reducible power amount of the wind turbine energy storage system, controlling each wind turbine to simultaneously use inertia response and the wind turbine energy storage system to reduce power. Specifically, in accordance with the principle of making full use of the inertia-reducible power amount of the wind turbine energy storage system, based on the power reduction amount of the entire field, the inertia-reducible power amount of each wind turbine, and the inertia-reducible power amount of the wind turbine energy storage system, determine the power reduction amount that each wind turbine needs to use inertia response adjustment and the power reduction amount that each wind turbine needs to adjust the energy storage system, and based on this, simultaneously control the inertia response of the wind turbine and the energy storage system of the wind turbine.

[0078] As an example, Fig. 9 As shown, the distributed DC energy storage (i.e., the energy storage system of each wind turbine) can be uniformly dispatched and managed through the field control equipment. The field control can calculate the actual adjustable capacity of the wind turbine inertia and the adjustable capacity of the distributed energy storage under the current SOC state, and then divide the total adjustment demand into two parts according to the calculation results. Usually, when the adjustment amount of the inertia response is 20% to 30% Pn, the adjustment accuracy is high, but if the adjustment amount of the inertia response is larger, the accuracy and time accuracy will be reduced. Therefore, the allocation principle can be set as follows: try to use all the adjustable energy of the distributed energy storage, and allocate the rest to the inertia response. The two actions of inertia response power reduction and distributed energy storage power reduction can be performed simultaneously. The field control issues two sets of adjustment instructions to the wind turbine, one to the inertia interface and the other to the energy storage interface.

[0079] As another example, the wind turbine may autonomously control its own energy storage system, and the step of controlling the wind turbine to use inertia response and the wind turbine energy storage system to reduce power may include: determining the single-machine power reduction amount that needs to be adjusted for each wind turbine based on the total power reduction amount, the inertia-reducible power amount of each wind turbine, and the wind turbine energy storage system-reducible power amount, and then issuing power adjustment instructions to each wind turbine based on the single-machine power reduction amount that needs to be adjusted for each wind turbine, so that each wind turbine uses inertia response and the wind turbine energy storage system to reduce power at the same time according to the received power adjustment instructions.

[0080] For example, Fig.10 As shown in the figure, the wind turbine master controls two groups of resources at the same time. In addition to controlling the pitch and torque group, it also controls the energy storage. The total control demand (i.e., the power reduction of a single machine) is sent by the field control equipment to the wind turbine master, which then distributes the power reduction of a single machine to the wind turbine torque and DC distributed energy storage. Torque response and energy storage power reduction are carried out simultaneously.

[0081] As another example, the wind turbine may autonomously control its own energy storage system, and the step of controlling the wind turbine to use inertia response and the wind turbine energy storage system to reduce power may include: determining the inertia reducible power amount of each wind turbine and the wind turbine energy storage system reducible power amount, and in accordance with the principle of making full use of the reducible power amount of the wind turbine energy storage system, based on the total power reduction amount, the inertia reducible power amount of each wind turbine, and the reducible power amount of the wind turbine energy storage system, controlling each wind turbine to use inertia response and the wind turbine energy storage system to reduce power at the same time.

[0082] For example, Fig.11 As shown, the wind turbine master controls the pitch and torque group, and the converter controller controls the energy storage. The field control can calculate the actual adjustable capacity of the wind turbine inertia and the adjustable capacity of the distributed energy storage under the current SOC state, and then divide the total regulation demand into two parts according to the calculation results. Usually, when the adjustment amount of the inertia response is 20% to 30% Pn, the regulation accuracy is high, but if the adjustment amount of the inertia response is larger, the accuracy and time accuracy will be reduced. Therefore, the allocation principle can be set as follows: try to use all the adjustable energy of the distributed energy storage, and then allocate the remaining to the inertia response. The two actions of inertia response power reduction and distributed energy storage power reduction can be carried out at the same time. The field control issues two groups of regulation instructions to the wind turbine. The first group of instructions is the total regulation demand, which is sent from the field control device to the converter controller via the wind turbine master. The second group of instructions is the torque instruction sent to the wind turbine inertia interface. The wind turbine master performs normal regulation. The converter controller starts the energy storage control according to the difference between the total instruction and the received torque instruction.

[0083] Figure 3 A flow chart showing a power reduction control method of a wind farm according to another exemplary embodiment of the present disclosure is shown.

[0084] Reference Figure 3 According to another exemplary embodiment of the present disclosure, a power reduction control method for a wind farm may include steps S400-S600 in addition to steps S100-S300.

[0085] In step S400 , in response to the inertia adjustment time being greater than the adjustment time parameter, the braking resistor activation amount required to complete the full field power reduction amount by using the inertia response and the braking resistor is calculated.

[0086] As an exemplary embodiment, the braking resistor activation amount DeltP required to complete the full-field power reduction amount DeltP using the inertia response and the braking resistor can be calculated by the following formula: break :

[0087] DeltP break =DeltP-t1*Rate Iner ,

[0088] Among them, the inertia adjustment time After rounding, we get t1, Rate Iner Indicates the adjustment rate of the inertia response.

[0089] In step S500, in response to the braking resistor activation amount being greater than a preset threshold, the fan is controlled to reduce power using the braking resistor.

[0090] As an example, the value of the preset threshold can be set according to the actual situation and specific needs, for example, it can be set to 10% Pn. break >10% Pn, the fan is controlled to use a braking resistor to reduce power.

[0091] When the fan uses a braking resistor to reduce power, it is also necessary to cooperate with a non-braking resistor power reduction method (for example, inertia response or primary frequency modulation) to reduce power. As an exemplary embodiment, step S500 may include: in response to the braking resistor activation amount being greater than a preset threshold, controlling the fan to reduce power by using a braking resistor and a non-braking resistor power reduction method.

[0092] As an exemplary embodiment, step S500 may include: in response to the braking resistor activation amount being greater than a preset threshold, in the first stage, the fan is controlled to reduce power by a non-braking resistor power reduction method, and then in the second stage, the fan is controlled to reduce power by both a non-braking resistor power reduction method and a braking resistor. Thus, when a braking resistor must be used to reduce power, the consumption of the braking resistor can be minimized. As an example, the fan may be controlled to reduce power according to a primary frequency modulation in the first stage, and then in the second stage, the fan may be controlled to reduce power by both a primary frequency modulation and a braking resistor; or, the fan may be controlled to reduce power according to an inertia response in the first stage, and then in the second stage, the fan may be controlled to reduce power by both a primary frequency modulation and a braking resistor. For example, for a regulation requirement of reducing Pn by 50% within 2s, the fan inertia response may be used to reduce Pn by 20% in the first second (i.e., the first stage), and then the fan primary frequency modulation and a braking resistor may be used to reduce Pn by 30% in the second second (i.e., the second stage).

[0093] In step S600 , in response to the braking resistor activation amount being less than or equal to a preset threshold, the field-level centralized energy storage system or the wind turbine energy storage system is controlled to reduce power instead of the braking resistor.

[0094] As an example, the field-level centralized energy storage system or the wind turbine energy storage system can be controlled to replace the braking resistor to reduce power according to the method of controlling the braking resistor in the exemplary embodiment of step S500. As another example, the field-level centralized energy storage system can be controlled to replace the braking resistor to reduce power according to the fourth embodiment. For example, for the regulation requirement of reducing 50% Pn within 2s, the wind turbine inertia response can be used to reduce 40% Pn in 2 seconds, and the remaining 10% Pn is adjusted by the field-level centralized energy storage system, which can meet the demand and completely abandon the consumption of the braking resistor. The wind turbine energy storage system can also be controlled to replace the braking resistor to reduce power according to the fifth embodiment. For example, for the regulation requirement of reducing 50% Pn within 2s, the wind turbine inertia response can be used to reduce 40% Pn in 2 seconds, and the remaining 10% Pn is adjusted by the wind turbine energy storage system, which can meet the demand and completely abandon the consumption of the braking resistor.

[0095] In the above embodiments, the power reduction controls such as pitch control, generator, and yaw are uniformly incorporated into the primary frequency modulation and inertia response. The present disclosure does not specifically reflect the detailed control strategy of the primary frequency modulation or inertia response inside the wind turbine, but only takes the comprehensive balanced regulation of the four resources of primary frequency modulation, inertia response, braking resistor, and energy storage control as the core idea. It is necessary to meet the requirements of speed and accuracy of the power grid, and to consider the safety and reliability of the wind turbine. Therefore, the available resources will be balanced, the strong dependence on a certain resource will be minimized, and the consumption of braking resistors will be minimized.

[0096] Figure 4 A flow chart showing a method for controlling a wind turbine to reduce power by simultaneously adopting a non-braking resistor power reduction method and a braking resistor in a second stage according to an exemplary embodiment of the present disclosure.

[0097] Reference Figure 4 In step S501, based on the total power reduction amount and the total power real-time value at the end of the first stage, the remaining power reduction amount that needs to be adjusted in the second stage is determined.

[0098] As an exemplary embodiment, the power reduction amount adjusted in the first stage can be determined based on the difference between the real-time value of the full-field power at the beginning of the first stage and the real-time value of the full-field power at the end of the first stage; and then the difference between the full-field power reduction amount and the power reduction amount adjusted in the first stage is used as the remaining power reduction amount that needs to be adjusted in the second stage.

[0099] In step S502, based on the remaining power reduction amount, the single-machine power reduction amount that needs to be adjusted by each wind turbine in the second stage is determined.

[0100] As an exemplary embodiment, the individual power reduction amount required to be adjusted may be allocated to each wind turbine based on the remaining power reduction amount and the power reduction amount of each wind turbine.

[0101] In step S503, based on the adjustment time parameters, the adjustment time of the first stage, the single-machine power reduction of each wind turbine and the control coefficient, the target adjustment rate for limiting the power output on the grid side (i.e., the grid side of the converter) of each wind turbine in the second stage is determined.

[0102] As an exemplary embodiment, the adjustment time of the first stage (i.e., the time spent in the first stage) can be rounded to obtain a first time value, and the difference between the adjustment time parameter and the first time value can be used as the second time value t2; then, for each wind turbine, the target adjustment rate of the grid-side power output restriction of the wind turbine in the second stage is calculated. Among them, Deltp break[i] Indicates the power reduction of the single unit that needs to be adjusted by the fan in the second stage. represents the control coefficient.

[0103] Because the brake resistor cannot accurately control the power, a regulation factor needs to be added , and adjust the control coefficient according to the actual situation and specific needs For example, if the power regulation speed is slow and the actual power response is small, increase the regulation coefficient. Otherwise, the control coefficient is reduced. .

[0104] In addition, according to the exemplary embodiment of the present disclosure, the method of controlling the wind turbine in the second stage by simultaneously using a non-braking resistor power reduction method and a braking resistor to reduce power may also include: sending to each wind turbine the single-machine power reduction amount that needs to be adjusted by the wind turbine, the target adjustment rate of the non-braking resistor power reduction method (for example, the target adjustment rate of primary frequency regulation or the target adjustment rate of inertia response), and the target adjustment rate of grid-side power output limitation to control the wind turbine to complete the second stage of power reduction adjustment.

[0105] It should be understood that for a wind turbine that does not have the power reduction capability of a braking resistor, it is not necessary to calculate and send a target regulation rate for limiting power output on the grid side.

[0106] Figure 5 An example of the existing wind turbine rapid power reduction curve when the frequency is seriously over-frequency is shown. Assume that the wind turbine needs to reduce Pn by 50% 单机 , P1(t) represents the control response according to primary frequency modulation (for example, controlling the wind turbine pitch to reduce wind energy and reduce the output power of the generator), and P2(t) represents the control response of grid-side power limitation (that is, the grid-side converter limits the active power output). There is a speed difference between the two, and the energy of this difference is consumed by the braking resistor, that is, the black shaded part in the middle represents the power absorbed by the braking resistor.

[0107] As an example of the present disclosure, compared with the first stage, the target regulation rate of limiting the power output of the wind turbine on the grid side in the second stage is higher. Since the braking resistor is not enabled in the first stage, the target regulation rate of the non-braking resistor power reduction method in the first stage is the target regulation rate of limiting the power output on the grid side.

[0108] like Figure 6 and Figure 7 As shown, compared to Figure 5 The braking resistor startup power point is reduced, so that the braking resistor consumption in the shaded area is reduced. Figure 6 and Figure 7 The slope of the P3 line in the 0-t3 time period (i.e., the first stage) (indicating the target regulation rate of the non-braking resistor power reduction method) is greater than the slope of the P4 line in the t3 to t4 time period (i.e., the second stage) (indicating the target regulation rate of the grid-side power output restriction). That is, in the entire regulation process, the variable speed regulation wind turbine limits the power output on the grid side. Through the variable speed method, the power point is first reduced, and then the braking resistor is enabled to reduce the power with a larger slope (less than the low penetration). In fact, compared with Figure 5 The slope of the P2 line in the figure is greater than that of the P4 line. According to the exemplary embodiment of the present disclosure, from the perspective of response speed, a suitable speed can be selected between the primary frequency modulation speed and the low-penetration response speed, or even a variable speed method can be used to achieve the desired effect, thereby minimizing the increase in the capacity of the brake resistor and reducing cost investment.

[0109] As another example of the present disclosure, the target adjustment rate of the non-braking resistor power reduction mode of the fan in the second stage is lower than that in the first stage. Figure 7 As shown, compared with the slope of the P3 line in the time period 0-t3, the slope of the P3 line in the time period t3 to t4 is smaller, that is, in the entire adjustment process, the target adjustment rate of the non-braking resistor power reduction method changes.

[0110] According to the above exemplary embodiments of the present disclosure, a time-varying rate control method for rapid power reduction is proposed.

[0111] Fig.12 A structural block diagram of a wind farm power reduction control device according to an exemplary embodiment of the present disclosure is shown.

[0112] like Fig.12 As shown, the power reduction control device of a wind farm according to an exemplary embodiment of the present disclosure includes: an adjustment amount determination unit 100 , an inertia adjustment time determination unit 200 , and a wind turbine control unit 300 .

[0113] The adjustment amount determination unit 100 is configured to determine the total power reduction amount that needs to be adjusted for the wind farm based on the adjustment amount parameter in response to the frequency of the grid connection point being greater than the overfrequency threshold parameter.

[0114] The inertia adjustment time determination unit 200 is configured to calculate the inertia adjustment time required to complete the full-field power reduction amount by adopting the inertia response.

[0115] The wind turbine control unit 300 is configured to, in response to the inertia adjustment time being less than or equal to the adjustment time parameter, cause the wind turbines in the wind farm to reduce power using non-braking resistors.

[0116] An overfrequency threshold parameter for defining a lower limit value of a severe overfrequency range, an adjustment amount parameter for defining an adjustment amount requirement for rapid power reduction, and an adjustment time parameter for defining an adjustment time requirement for rapid power reduction are preset.

[0117] As an exemplary embodiment, the wind turbine control unit 300 may be configured to: in response to the inertia adjustment time being greater than the adjustment time parameter, calculate the braking resistor activation amount required to complete the full-field power reduction amount using the inertia response and the braking resistor; in response to the braking resistor activation amount being greater than a preset threshold, control the wind turbine to use the braking resistor to reduce power; in response to the braking resistor activation amount being less than or equal to the preset threshold, control the field-level centralized energy storage system or the wind turbine energy storage system to reduce power instead of the braking resistor.

[0118] As an exemplary embodiment, the fan control unit 300 may be configured to: in the first stage, control the fan to reduce power by using a non-braking resistor power reduction method, and then in the second stage, control the fan to reduce power by using both a non-braking resistor power reduction method and a braking resistor.

[0119] As an exemplary embodiment, compared with the first stage, the target regulation rate for limiting the grid-side power output of the wind turbine in the second stage is higher.

[0120] As an exemplary embodiment, compared with the first stage, the target regulation rate of the non-braking resistor power reduction method of the wind turbine in the second stage is lower.

[0121] As an exemplary embodiment, the fan control unit 300 can be configured to: determine the remaining power reduction amount that needs to be adjusted in the second stage based on the total power reduction amount and the real-time value of the total power at the end of the first stage; determine the single-machine power reduction amount that needs to be adjusted for each fan in the second stage based on the remaining power reduction amount; determine the target adjustment rate of the grid-side power output limitation of each fan in the second stage based on the adjustment time parameter, the adjustment time of the first stage, the single-machine power reduction amount of each fan and the control coefficient.

[0122] As an exemplary embodiment, the wind turbine control unit 300 may be configured to control the wind turbine to reduce power by using at least one of inertia response, primary frequency modulation, and a wind turbine energy storage system.

[0123] As an exemplary embodiment, the wind turbine control unit 300 may be configured to: control the wind turbine to reduce power only by inertia response; or, control the wind turbine to first reduce power by inertia response, and then reduce power by primary frequency modulation; or, control the wind turbine to first reduce power by primary frequency modulation, and then reduce power by inertia response; or, control the wind turbine to reduce power by inertia response, and control the field-level centralized energy storage system to reduce power; or, control the wind turbine to reduce power by inertia response and the wind turbine energy storage system.

[0124] As an exemplary embodiment, the wind turbine control unit 300 can be configured to: determine the power reduction amount of the field-level centralized energy storage system and the power reduction amount of the inertia of each wind turbine; in accordance with the principle of making full use of the power reduction amount of the field-level centralized energy storage system, based on the power reduction amount of the entire field, the power reduction amount of the field-level centralized energy storage system and the power reduction amount of the inertia of each wind turbine, simultaneously control the field-level centralized energy storage system to reduce power and each wind turbine to reduce power by adopting inertia response.

[0125] As an exemplary embodiment, the wind turbine control unit 300 may be configured to: determine the inertia power reduction amount of each wind turbine and the power reduction amount of the wind turbine energy storage system, and in accordance with the principle of making full use of the power reduction amount of the wind turbine energy storage system, based on the total power reduction amount, the inertia power reduction amount of each wind turbine and the power reduction amount of the wind turbine energy storage system, control each wind turbine to simultaneously use inertia response and the wind turbine energy storage system to reduce power; or, based on the single-machine power reduction amount that needs to be adjusted by each wind turbine, issue power adjustment instructions to each wind turbine respectively, so that each wind turbine simultaneously uses inertia response and the wind turbine energy storage system to reduce power according to the received power adjustment instructions.

[0126] It should be understood that the specific processing performed by the power reduction control device of the wind farm according to the exemplary embodiment of the present disclosure has been referred to. Figures 2 to 11 The details have been described in detail and will not be repeated here.

[0127] It should be understood that the various units in the power reduction control device for a wind farm according to the exemplary embodiment of the present disclosure may be implemented as hardware components and / or software components. Those skilled in the art may implement the various units, for example, using a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC) according to the processing performed by the various defined units.

[0128] According to an exemplary embodiment of the present disclosure, a controller of a wind farm includes: a processor (not shown) and a memory (not shown), wherein the memory stores a computer program, and when the computer program is executed by the processor, the power reduction control method of the wind farm as described in the above exemplary embodiment is implemented.

[0129] According to an exemplary embodiment of the present disclosure, a computer-readable storage medium storing instructions may also be provided, wherein when the instructions are executed by at least one processor, the at least one processor is prompted to execute the power reduction control method for a wind farm as described in the above exemplary embodiment. Examples of computer-readable storage media here include: read-only memory (ROM), random access programmable read-only memory (PROM), electrically erasable programmable read-only memory (EEPROM), random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), flash memory, non-volatile memory, CD-ROM, CD-R, CD+R, CD-RW, CD+RW, DVD-ROM, DVD-R, DVD+R, DVD-RW, DVD+RW, DVD-RAM, BD-ROM, BD-R, BD-R LTH, BD-RE, Blu-ray or optical disk storage, hard disk drive (HDD), solid state drive (SSD), card storage (such as, multimedia card, secure digital (SD) card or extreme digital (XD) card), magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid state disk and any other device, any other device is configured to store computer programs and any associated data, data files and data structures in a non-transitory manner and provide the computer programs and any associated data, data files and data structures to a processor or computer so that the processor or computer can execute the computer program. The computer program in the above-mentioned computer-readable storage medium can be run in an environment deployed in a computer device such as a client, a host, an agent device, a server, etc. In addition, in one example, the computer program and any associated data, data files and data structures are distributed on a networked computer system, so that the computer program and any associated data, data files and data structures are stored, accessed and executed in a distributed manner by one or more processors or computers.

[0130] According to an exemplary embodiment of the present disclosure, a computer program product may also be provided, and instructions in the computer program product may be executed by at least one processor to implement the power reduction control method for a wind farm as described in the above exemplary embodiment.

[0131] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the claims.

[0132] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A power reduction control method for a wind farm, characterized in that: include: In response to the frequency of the grid connection point being greater than an overfrequency threshold parameter, determining a total power reduction amount that needs to be adjusted by the wind farm based on an adjustment amount parameter; Calculating the inertia adjustment time required to complete the full-field power reduction using the inertia response; In response to the inertia adjustment time being less than or equal to the adjustment time parameter, controlling the wind turbines in the wind farm to reduce power by adopting a non-braking resistor power reduction method; Among them, an overfrequency threshold parameter for limiting the lower limit value of the severe overfrequency range, an adjustment amount parameter for limiting the adjustment amount requirement for rapid power reduction, and an adjustment time parameter for limiting the adjustment time requirement for rapid power reduction are pre-set.

2. The power reduction control method according to claim 1, characterized in that: Also includes: In response to the inertia adjustment time being greater than the adjustment time parameter, calculating the brake resistor activation amount required to complete the full-field power reduction amount using the inertia response and the brake resistor; In response to the braking resistor activation amount being greater than a preset threshold, controlling the fan to reduce power using the braking resistor; In response to the braking resistor activation amount being less than or equal to the preset threshold, the field-level centralized energy storage system or the wind turbine energy storage system is controlled to reduce power instead of the braking resistor.

3. The power reduction control method according to claim 2, characterized in that: The step of controlling the fan to reduce power by using a braking resistor comprises: In the first stage, the fan is controlled to reduce power by using a non-braking resistor power reduction method, and then in the second stage, the fan is controlled to reduce power by using both a non-braking resistor power reduction method and a braking resistor.

4. The power reduction control method according to claim 3, characterized in that: Compared with the first stage, the target regulation rate of limiting the power output of the wind turbine on the grid side in the second stage is higher; And / or, compared with the first stage, the target regulation rate of the non-braking resistor power reduction method of the fan in the second stage is lower.

5. The power reduction control method according to claim 3 or 4, characterized in that: The step of controlling the fan to reduce power by simultaneously using a non-braking resistor power reduction method and a braking resistor in the second stage includes: Determining a remaining power reduction amount that needs to be adjusted in the second stage based on the full-field power reduction amount and the full-field power real-time value at the end of the first stage; Based on the remaining power reduction amount, determining a single-machine power reduction amount that needs to be adjusted by each wind turbine in the second stage; Based on the adjustment time parameter, the adjustment time of the first stage, the single-machine power reduction of each wind turbine and the regulation coefficient, a target adjustment rate for limiting the grid-side power output of each wind turbine in the second stage is determined.

6. The power reduction control method according to claim 1, characterized in that: The step of controlling the wind turbines in the wind farm to reduce power by adopting a non-braking resistor power reduction method comprises: The fan is controlled to reduce power by using at least one of inertia response, primary frequency modulation, and a fan energy storage system.

7. The power reduction control method according to claim 6, characterized in that: The step of controlling the fan to reduce power by using at least one of inertia response, primary frequency modulation, and a fan energy storage system comprises: Control the fan to reduce power using only inertia response; Alternatively, the fan is controlled to first reduce power using inertia response and then to reduce power using primary frequency modulation; Alternatively, the fan is controlled to first reduce power by using primary frequency modulation, and then reduce power by using inertia response; Alternatively, the wind turbines are controlled to reduce power using inertia response, and the field-level centralized energy storage system is controlled to reduce power; Alternatively, control the wind turbine using inertia response and wind turbine energy storage systems to reduce power.

8. The power reduction control method according to claim 7, characterized in that: The steps of controlling the wind turbine to reduce power by adopting inertia response and controlling the field-level centralized energy storage system to reduce power include: Determine the power reduction amount of the field-level centralized energy storage system and the power reduction amount of the inertia of each wind turbine; In accordance with the principle of making full use of the reducible power of the field-level centralized energy storage system, based on the power reduction of the entire field, the reducible power of the field-level centralized energy storage system and the inertia reducible power of each wind turbine, the field-level centralized energy storage system is controlled to reduce power and each wind turbine adopts inertia response to reduce power.

9. The power reduction control method according to claim 7, characterized in that: The steps of controlling the wind turbine to reduce power by using inertia response and a wind turbine energy storage system include: Determine the inertia power reduction amount of each wind turbine and the power reduction amount of the wind turbine energy storage system, and according to the principle of making full use of the power reduction amount of the wind turbine energy storage system, control each wind turbine to simultaneously use inertia response and the wind turbine energy storage system to reduce power based on the total power reduction amount, the inertia power reduction amount of each wind turbine and the power reduction amount of the wind turbine energy storage system; Alternatively, a power adjustment command is issued to each wind turbine based on the power reduction amount of each wind turbine that needs to be adjusted, so that each wind turbine reduces power by using inertia response and wind turbine energy storage system at the same time according to the received power adjustment command.

10. A power reduction control device for a wind farm, characterized in that: include: an adjustment amount determination unit, configured to determine, in response to the frequency of the grid connection point being greater than an overfrequency threshold parameter, a total power reduction amount that needs to be adjusted by the wind farm based on the adjustment amount parameter; an inertia adjustment time determination unit, configured to calculate the inertia adjustment time required to complete the full-field power reduction amount by adopting the inertia response; a wind turbine control unit configured to, in response to the inertia adjustment time being less than or equal to an adjustment time parameter, reduce power of the wind turbines in the wind farm using non-braking resistors; Among them, an overfrequency threshold parameter for limiting the lower limit value of the severe overfrequency range, an adjustment amount parameter for limiting the adjustment amount requirement for rapid power reduction, and an adjustment time parameter for limiting the adjustment time requirement for rapid power reduction are pre-set.

11. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the processor is prompted to execute the power reduction control method for a wind farm as claimed in any one of claims 1 to 9.

12. A controller for a wind farm, characterized in that: include: processor; A memory stores a computer program, which, when executed by a processor, prompts the processor to execute the power reduction control method for a wind farm as claimed in any one of claims 1 to 9.

13. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the power reduction control method for a wind farm as claimed in any one of claims 1 to 9 is implemented.

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