Direct-driven wind turbine generator inertia control method and device, terminal equipment and storage medium

Abstract

The invention discloses a direct-drive wind turbine generator inertia control method and device, terminal equipment and a storage medium, and the method comprises the steps: obtaining a plurality of fans which can be operated in an overspeed and deloading manner in a wind power cluster of a power system as a plurality of to-be-processed fans, and obtaining the wind power data of the power system; according to the wind power data, constructing a target function by taking maximization of rotor kinetic energy as a target; constructing a power balance constraint and a power out-of-limit constraint of the target function based on the wind power data; under the constraint of the power balance constraint and the power out-of-limit constraint, solving the objective function, and generating the optimized power of each to-be-processed fan when the kinetic energy of the rotor is maximized; controlling each fan to be processed to output the optimized power; and acquiring the frequency change rate of the power system when each to-be-processed fan outputs the optimized power, and controlling the output inertia of each to-be-processed fan according to the frequency change rate of the power system. According to the invention, the operation stability and safety of the power system can be improved.

Description

Technical Field

[0001] The present invention relates to the field of renewable energy power generation control technology, and in particular to a direct-drive wind turbine inertia control method, device, terminal equipment and storage medium. Background Art

[0002] As the global energy structure transforms toward low-carbonization and carbon reduction targets are being pursued, wind power generation, as a clean and renewable energy source, has gradually become an important part of the energy strategies of countries around the world. Wind turbines have become one of the important means to address climate change and reduce carbon emissions due to their environmental friendliness and increasingly mature technology. However, with the access of large-scale wind turbines to the power grid, the inertia level of the power system has decreased, and the stability of the power system has been affected. Existing wind turbines are generally in MPPT operation mode and do not provide inertia support to the power system, resulting in insufficient inertia support during the power system frequency response, causing instability in the system. Summary of the invention

[0003] The embodiments of the present invention provide a direct-drive wind turbine inertia control method, device, terminal equipment and storage medium, which can provide inertia support for an electric power system and improve the operational stability and safety of the electric power system.

[0004] An embodiment of the present invention provides an inertia control method for a direct-drive wind turbine generator set, comprising:

[0005] A number of wind turbines capable of overspeed and load reduction operation in a wind power cluster of a power system are obtained as a number of wind turbines to be processed, and wind power data of the power system is obtained; wherein the wind power data includes: an angular velocity of each wind turbine, a pitch angle of each wind turbine, a maximum output power of the wind turbine, a minimum output power of the wind turbine, and a mapping relationship between the output power of each wind turbine and the kinetic energy of the rotor;

[0006] According to the wind power data, construct an objective function with the goal of maximizing rotor kinetic energy; and construct a power balance constraint and a power over-limit constraint of the objective function based on the wind power data;

[0007] Under the constraints of the power balance constraint and the power over-limit constraint, the objective function is solved to generate the optimized power of each wind turbine to be processed when the rotor kinetic energy is maximized;

[0008] Controlling each fan to be processed to output the optimized power;

[0009] The frequency change rate of the power system when each wind turbine to be processed outputs the optimized power is obtained, and the output inertia of each wind turbine to be processed is controlled according to the frequency change rate of the power system.

[0010] Further, the controlling the output inertia of each wind turbine to be processed according to the frequency change rate of the power system includes:

[0011] If the frequency change rate is not less than the maximum frequency change rate of the power system, the output inertia of each wind turbine to be processed is controlled to be the first inertia; wherein the first inertia is the initial output inertia of the wind turbine to be processed;

[0012] If the frequency change rate is less than the maximum frequency change rate of the power system, obtaining the rotation speed of each wind turbine to be processed when the frequency change rate is less than the maximum frequency change rate of the power system;

[0013] For each fan to be processed, when the rotation speed is less than the minimum rotation speed limit, the output inertia of the current fan to be processed is controlled to be zero;

[0014] When the rotation speed is not less than the minimum rotation speed limit, if the rotation speed is less than the optimal rotation speed value, the output inertia of the fan to be processed is controlled to be the second inertia; wherein the second inertia is the maximum rotation speed frequency change value;

[0015] If the rotation speed is greater than the optimal rotation speed value, the output inertia of the fan to be processed is controlled to be the third inertia; wherein the third inertia is the required rotation speed frequency change value.

[0016] Furthermore, for each fan to be processed, when the rotation speed is less than the minimum rotation speed limit, before controlling the output inertia of the current fan to be processed to zero, the method further includes:

[0017] If the frequency change rate is less than the maximum frequency change rate of the power system, the system inertia requirement is determined according to the system demand power, the optimized power and the maximum frequency change rate.

[0018] Further, determining the system inertia requirement according to the system required power, the optimized power and the maximum frequency change rate includes:

[0019] Determining the system power deficit according to the system required power and the optimized power;

[0020] The system inertia requirement is determined according to the maximum frequency change rate and the system power shortage.

[0021] Furthermore, the third inertia is determined according to the inertia time constant of the fan rotor, the angular velocity of the fan and the system inertia requirement.

[0022] Furthermore, the objective function is specifically:

[0023]

[0024] Among them, F i is the mapping between the rotor kinetic energy and the captured power of the i-th wind turbine to be processed; P iis the power allocated to the i-th fan to be processed; n is the total number of fans to be processed.

[0025] Furthermore, the power balance constraint is specifically:

[0026]

[0027] The power limit constraint is specifically:

[0028]

[0029] Among them, P i is the power allocated to the i-th wind turbine to be processed; n is the total number of wind turbines to be processed; ω i is the angular velocity of the i-th fan; β i is the pitch angle of the i-th wind turbine; is the minimum output power of the fan; The maximum output power of the fan.

[0030] Based on the above method embodiment, the present invention provides a corresponding device embodiment;

[0031] An embodiment of the present invention provides an inertia control device for a direct-drive wind turbine generator set, comprising: a data acquisition module, an objective function and constraint construction module, an objective function solving module, a power control module and an inertia control module;

[0032] The data acquisition module is used to acquire a number of wind turbines capable of overspeed and load reduction operation in the wind power cluster of the power system as a number of wind turbines to be processed, and acquire wind power data of the power system; wherein the wind power data includes: the angular velocity of each wind turbine, the pitch angle of each wind turbine, the maximum output power of the wind turbine, the minimum output power of the wind turbine, and the mapping relationship between the output power of each wind turbine and the rotor kinetic energy;

[0033] The objective function and constraint building module is used to build an objective function based on the wind power data with the goal of maximizing the rotor kinetic energy; and to build a power balance constraint and a power over-limit constraint of the objective function based on the wind power data;

[0034] The objective function solving module is used to solve the objective function under the constraints of the power balance constraint and the power over-limit constraint to generate the optimized power of each wind turbine to be processed when the rotor kinetic energy is maximized;

[0035] The power control module is used to control each wind turbine to be processed to output the optimized power;

[0036] The inertia control module is used to obtain the frequency change rate of the power system when each wind turbine to be processed outputs the optimized power, and control the output inertia of each wind turbine to be processed according to the frequency change rate of the power system.

[0037] Another embodiment of the present invention provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and when the processor executes the computer program, a direct-drive wind turbine inertia control method described in the above-mentioned embodiment of the invention is implemented.

[0038] Another embodiment of the present invention provides a storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the storage medium is located is controlled to execute the direct-drive wind turbine inertia control method described in the above-mentioned embodiment of the invention.

[0039] The following beneficial effects are achieved by implementing the present invention:

[0040] The present invention provides a direct-drive wind turbine inertia control method, device, terminal equipment and storage medium. The inertia control method obtains several wind turbines in the wind power cluster of the power system that can operate at overspeed and load reduction as several wind turbines to be processed, and obtains wind power data of the power system; based on the wind power data, with the goal of maximizing the rotor kinetic energy, constructs an objective function and its power balance constraint and power over-limit constraint, and then solves the objective function under the above constraints to obtain the optimized power output by each wind turbine to be processed, determines the frequency change rate of the power system based on the optimized power, and then controls the output inertia of each wind turbine to be processed according to the frequency change rate of the power system. The output inertia of each wind turbine to be processed is controlled by determining the frequency change rate of the power system under the maximum rotor kinetic energy, so that each wind turbine to be processed adjusts the inertia output based on the output power and the frequency change rate, provides inertia support to the power system, avoids insufficient inertia support when the power system frequency responds, and causes instability in the system, thereby improving the operational stability and safety of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a flow chart of an inertia control method for a direct-drive wind turbine set provided by an embodiment of the present invention.

[0042] Figure 2 A nonlinear mapping relationship diagram between different wind turbine rotor kinetic energies and wind turbine captured power is obtained by using a numerical method, provided by an embodiment of the present invention.

[0043] Figure 3 It is a mapping relationship diagram between different wind turbine rotor kinetic energy change rates and wind turbine capture power provided by an embodiment of the present invention.

[0044] Figure 4 It is a diagram of system frequency response simulation results provided by an embodiment of the present invention.

[0045] Figure 5 This is a diagram of the simulation results of the fan speed change provided by an embodiment of the present invention.

[0046] Figure 6 It is a structural schematic diagram of an inertia control device for a direct-drive wind turbine set provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] like Figure 1 As shown, a method for controlling inertia of a direct-drive wind turbine generator set provided by an embodiment of the present invention includes:

[0049] Step S1: obtaining a number of wind turbines capable of overspeed and load reduction operation in a wind power cluster of a power system as a number of wind turbines to be processed, and obtaining wind power data of the power system; wherein the wind power data includes: an angular velocity of each wind turbine, a pitch angle of each wind turbine, a maximum output power of the wind turbine, a minimum output power of the wind turbine, and a mapping relationship between the output power of each wind turbine and the kinetic energy of the rotor;

[0050] Step S2: constructing an objective function according to the wind power data with the goal of maximizing the rotor kinetic energy; and constructing a power balance constraint and a power over-limit constraint of the objective function based on the wind power data;

[0051] Step S3: Under the constraints of the power balance constraint and the power over-limit constraint, the objective function is solved to generate the optimized power of each wind turbine to be processed when the rotor kinetic energy is maximized;

[0052] Step S4: controlling each wind turbine to be processed to output the optimized power;

[0053] Step S5: obtaining the frequency change rate of the power system when each wind turbine to be processed outputs the optimized power, and controlling the output inertia of each wind turbine to be processed according to the frequency change rate of the power system.

[0054] For step S1, a number of wind turbines in the wind power cluster of the power system that can achieve overspeed and load reduction operation are obtained as a number of wind turbines to be processed, and wind power data in the wind power cluster of the power system is obtained; wherein the wind power data includes the angular velocity of each wind turbine, the pitch angle of each wind turbine, the maximum output power of the wind turbine, the minimum output power of the wind turbine, and the mapping relationship between the output power of each wind turbine and the rotor kinetic energy.

[0055] Preferably, the mapping relationship between the output power of each wind turbine and the rotor kinetic energy is determined based on the energy capture equation of the wind turbine and the wind turbine rotor kinetic energy equation.

[0056] The energy capture equation for a wind turbine is:

[0057]

[0058] Among them, P ω P is the per unit value of the power captured by the wind turbine; B is the rated output power of the fan; ρ is the air density; R is the radius of the wind wheel; v is the wind speed; C p is the wind energy utilization coefficient; λ is the tip speed ratio of the wind turbine; β is the pitch angle of the wind turbine; λ i is the intermediate value derived from the formula; ω is the angular velocity of the wind wheel.

[0059] The expression of the fan rotor kinetic energy is:

[0060] K=Jω 2 ;

[0061] Among them, K is the kinetic energy of the fan rotor; J is the moment of inertia of the fan rotor; ω is the angular velocity of the wind wheel.

[0062] The mapping relationship between the wind turbine rotor kinetic energy and the wind turbine capture power (i.e., wind turbine output power) can be obtained from the wind turbine energy capture equation and the rotor kinetic energy expression:

[0063]

[0064] It should be noted that since the mapping relationship in the above formula is a nonlinear equation involving exponents and fractions, it is usually impossible to directly solve the relationship between K and P. ω Therefore, in the present invention, a numerical method is used to obtain the nonlinear mapping relationship between different wind turbine rotor kinetic energy and wind turbine capture power. The nonlinear mapping relationship is as follows: Figure 2 shown.

[0065] For steps S2-S4, based on the data obtained in step S1, with the goal of maximizing the rotor kinetic energy, construct the objective function and the power balance constraint and power over-limit constraint of the objective function, and solve the objective function under the power balance constraint and power over-limit constraint to obtain the optimized power of each wind turbine to be processed when maximizing the rotor kinetic energy.

[0066] Specifically, in large wind farms, some wind turbines in overspeed load reduction mode maintain a certain power variation margin, and the remaining wind turbines are in maximum power tracking mode to fully improve wind energy utilization. Wind turbines provide inertia support to the system by releasing rotor kinetic energy. In the load reduction operation mode, the power distribution between wind turbines should be aimed at maximizing the rotor kinetic energy.

[0067] In a preferred embodiment, the objective function is specifically:

[0068]

[0069] Among them, F i is the mapping between the rotor kinetic energy and the captured power of the i-th wind turbine to be processed; P i is the power allocated to the i-th fan to be processed; n is the total number of fans to be processed.

[0070] In a preferred embodiment, the wind turbine generator set needs to satisfy a power balance constraint, wherein the power balance constraint is specifically:

[0071]

[0072] The output power of the fan should not exceed the limit. The power limit constraint is as follows:

[0073]

[0074] Among them, P i is the power allocated to the i-th wind turbine to be processed; n is the total number of wind turbines to be processed; ω i is the angular velocity of the i-th fan; β i is the pitch angle of the i-th wind turbine; is the minimum output power of the fan; The maximum output power of the fan.

[0075] Preferably, the objective function and constraints are standardized and sorted, and the following can be obtained:

[0076]

[0077] Among them, st represents constraint; represents the negative number of the rotor kinetic energy of the i-th fan to be processed; h sum represents the overall power balance constraint; is the lower limit constraint of the output power of the i-th wind turbine to be processed; is the output power upper limit constraint of the i-th wind turbine to be processed.

[0078] By constructing Lagrangian function to solve KKT condition, the optimal power of each wind turbine to be processed in the wind farm under overspeed load reduction condition can be obtained. The output power of each wind turbine to be processed is controlled to be the optimal power of each wind turbine to be processed.

[0079] For step S5, before optimizing the frequency change rate of the power system according to the output power of each wind turbine to be processed and controlling the output inertia of each wind turbine to be processed according to the frequency change rate, it is preferably necessary to analyze the inertia level of the direct-drive wind turbine in the overspeed load reduction mode.

[0080] In the overspeed load reduction mode, the speed of the wind wheel is greater than the speed in the MPPT mode, so that the tip speed ratio λ of the fan is greater than the optimal tip speed ratio λ of the fan. opt When the wind turbine senses that the system frequency is decreasing, it reduces the tip speed ratio by reducing the rotor speed, thereby increasing the wind energy utilization coefficient C. p Achieve an increase in wind turbine capture power.

[0081]

[0082] A(λ)<0,λ>λ opt ;

[0083] A(λ)=0,λ=λ opt ;

[0084] A(λ)>0,λ<λ opt ;

[0085] Where, λ is the tip speed ratio; A is the function of the tip speed ratio λ; λ opt It is the optimal tip speed ratio of the fan.

[0086] Considering that the decrease in wind rotor speed will release some kinetic energy, the equivalent inertia of the wind rotor will increase. Without considering the change in wind speed and the loss of wind energy capture, the equivalent inertia of the wind rotor in the overspeed load reduction mode can be expressed as:

[0087]

[0088] Among them, T J is the inertia time constant of the fan rotor; ω is the angular velocity of the wind wheel; H equ is the equivalent inertia of the fan.

[0089] When considering that the fan provides inertia support based on frequency changes rather than its own speed changes, that is, considering that the fan provides inertia support based on virtual inertia control, the expression of equivalent inertia is as follows:

[0090]

[0091]

[0092] Subtracting the two equations, we get:

[0093]

[0094] Among them, H equis the equivalent inertia of the fan; P is the fan rotor speed change rate; ω0 is the initial output power of the fan; P es is the AC power output by the grid-side converter; H v Virtual inertia that can be provided for the fan; is the frequency change rate; P ref It is the active power reference value of the grid-side converter.

[0095] Initially, the wind turbine is running in a stable state, and the active reference value is the wind energy capture power, so the two terms on the right side of the above equation are equal. When the system frequency changes, the virtual inertia time constant H can be obtained. v The equivalent inertia time constant H of the wind wheel equ The relationship between them is:

[0096]

[0097] Based on the equivalent inertia and virtual inertia logic derived above, the inertia of each wind turbine to be processed in the direct-drive wind turbine set is controlled.

[0098] In a preferred embodiment, the output inertia of each wind turbine to be processed is controlled according to the frequency change rate of the power system, including: if the frequency change rate is not less than the maximum frequency change rate of the power system, the output inertia of each wind turbine to be processed is controlled to be the first inertia; wherein the first inertia is the initial output inertia of the wind turbine to be processed; if the frequency change rate is less than the maximum frequency change rate of the power system, the rotation speed of each wind turbine to be processed when the frequency change rate is less than the maximum frequency change rate of the power system is obtained; for each wind turbine to be processed, when the rotation speed is less than the minimum rotation speed limit, the output inertia of the current wind turbine to be processed is controlled to be zero; when the rotation speed is not less than the minimum rotation speed limit, if the rotation speed is less than the optimal rotation speed value, the output inertia of the current wind turbine to be processed is controlled to be the second inertia; wherein the second inertia is the maximum rotation speed frequency change value; if the rotation speed is greater than the optimal rotation speed value, the output inertia of the current wind turbine to be processed is controlled to be the third inertia; wherein the third inertia is the required rotation speed frequency change value.

[0099] Specifically, first compare the frequency change rate and the maximum frequency change rate to determine whether the current frequency change rate has reached the limit. If the maximum frequency change rate has been reached, there is no need to control each fan to be processed to provide inertia support, and the initial output inertia can be directly used, that is, there is no intervention in the inertia output of each fan to be processed. If the maximum frequency change rate has not been reached, the next judgment is performed to obtain the rotational speed of each fan to be processed at this time, and a rotational speed judgment is made for each fan to be processed. For each fan to be processed, when the speed is less than the minimum speed limit, the output inertia of the current fan to be processed is controlled to be zero, that is, the inertia support of the current fan to be processed is stopped; when the speed is not less than the minimum speed limit, if it is still less than the optimal speed value, that is, when the current speed is between the minimum speed limit and the optimal speed value, the output inertia of the current fan is controlled to be the maximum speed frequency change value, that is, according to Release inertia. When the speed is not less than the minimum speed limit and greater than the optimal speed value, the output inertia of the fan to be processed is controlled to the required speed frequency change value.

[0100] In a preferred embodiment, for each wind turbine to be processed, when the speed is less than the minimum speed limit, before controlling the output inertia of the current wind turbine to be processed to zero, it also includes: if the frequency change rate is less than the maximum frequency change rate of the power system, determining the system inertia requirement according to the system demand power, the optimized power and the maximum frequency change rate.

[0101] In a preferred embodiment, determining the system inertia requirement based on the system demand power, the optimized power and the maximum frequency change rate includes: determining the system power deficit based on the system demand power and the optimized power; determining the system inertia requirement based on the maximum frequency change rate and the system power deficit.

[0102] Specifically, the system inertia requirement is calculated using the following formula:

[0103]

[0104] Among them, H need is the system inertia requirement; λP is the system power deficit; RoCoF max is the maximum frequency change rate.

[0105] In a preferred embodiment, the third inertia is determined according to the inertia time constant of the fan rotor, the angular velocity of the fan and the system inertia requirement.

[0106] Specifically, the third inertia released is:

[0107]

[0108] in, is the required speed frequency change value, that is, the third inertia; Hneed is the system inertia requirement; T J is the inertia time constant of the fan rotor; ω is the angular velocity of the fan.

[0109] It should be noted that the main operating parameters of each fan are shown in the following table:

[0110]

[0111] Based on the above data, the mapping relationship between the change rate of the kinetic energy of the wind turbine rotor and the wind turbine capture power can be obtained, such as Figure 3 Considering that there are methods of power distribution such as average distribution and distribution according to initial ratio, the present invention evaluates the rotor kinetic energy of each fan under three different power distribution modes when the system power demand increases from the initial 3.21pu to 3.51pu. The results are shown in the following table. According to the results in the following table, it can be seen that the power distribution method proposed by the present invention can improve the rotor kinetic energy of the fan while maintaining power balance.

[0112]

[0113] Build a simulation model in Simu Link based on the parameters in the following table:

[0114]

[0115] The system frequency response obtained by the method of the present invention after the inertia control simulation of the fan is as follows: Figure 4 As shown, the fan speed changes as Figure 5 As shown in the figure, it can be seen that the inertia control method of the present invention can reduce the change of the fan speed under the premise of satisfying the system frequency conversion as much as possible, which is conducive to the rapid recovery of the system frequency, avoids the secondary frequency drop in the frequency response recovery stage, and improves the stability and safety of the system operation.

[0116] like Figure 6 As shown, an embodiment of the present invention provides an inertia control device for a direct-drive wind turbine generator set, comprising: a data acquisition module, an objective function and constraint construction module, an objective function solving module, a power control module and an inertia control module;

[0117] The data acquisition module is used to acquire a number of wind turbines capable of overspeed and load reduction operation in the wind power cluster of the power system as a number of wind turbines to be processed, and acquire wind power data of the power system; wherein the wind power data includes: the angular velocity of each wind turbine, the pitch angle of each wind turbine, the maximum output power of the wind turbine, the minimum output power of the wind turbine, and the mapping relationship between the output power of each wind turbine and the rotor kinetic energy;

[0118] The objective function and constraint building module is used to build an objective function based on the wind power data with the goal of maximizing the rotor kinetic energy; and to build a power balance constraint and a power over-limit constraint of the objective function based on the wind power data;

[0119] The objective function solving module is used to solve the objective function under the constraints of the power balance constraint and the power over-limit constraint to generate the optimized power of each wind turbine to be processed when the rotor kinetic energy is maximized;

[0120] The power control module is used to control each wind turbine to be processed to output the optimized power;

[0121] The inertia control module is used to obtain the frequency change rate of the power system when each wind turbine to be processed outputs the optimized power, and control the output inertia of each wind turbine to be processed according to the frequency change rate of the power system.

[0122] It should be noted that the device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the accompanying drawings of the device embodiments provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art may understand and implement it without paying any creative effort.

[0123] Those skilled in the art can clearly understand that for the sake of convenience and brevity, the specific working process of the device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0124] Based on the above method item embodiments, the present invention provides corresponding terminal device item embodiments.

[0125] An embodiment of the present invention provides a terminal device, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, a direct-drive wind turbine inertia control method as described in any one of the present invention is implemented.

[0126] The terminal device may be a computing device such as a desktop computer, a notebook, a PDA, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0127] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the terminal device, and uses various interfaces and lines to connect various parts of the entire terminal device.

[0128] The memory can be used to store the computer program, and the processor realizes various functions of the terminal device by running or executing the computer program stored in the memory and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application required for a function, etc.; the data storage area can store data created according to the use of the mobile phone, etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Med ia Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0129] Based on the above method item embodiments, the present invention provides a corresponding storage medium item embodiment.

[0130] An embodiment of the present invention provides a storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the storage medium is located is controlled to execute any one of the direct-drive wind turbine inertia control methods described in the present invention.

[0131] The storage medium is a computer-readable storage medium, and the computer program is stored in the computer-readable storage medium. When the computer program is executed by the processor, the steps of each of the above-mentioned method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium.

[0132] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A direct-drive wind turbine inertia control method, characterized in that: include: A number of wind turbines capable of overspeed and load reduction operation in a wind power cluster of a power system are obtained as a number of wind turbines to be processed, and wind power data of the power system is obtained; wherein the wind power data includes: an angular velocity of each wind turbine, a pitch angle of each wind turbine, a maximum output power of the wind turbine, a minimum output power of the wind turbine, and a mapping relationship between the output power of each wind turbine and the kinetic energy of the rotor; According to the wind power data, construct an objective function with the goal of maximizing rotor kinetic energy; and construct a power balance constraint and a power over-limit constraint of the objective function based on the wind power data; Under the constraints of the power balance constraint and the power over-limit constraint, the objective function is solved to generate the optimized power of each wind turbine to be processed when the rotor kinetic energy is maximized; Controlling each fan to be processed to output the optimized power; The frequency change rate of the power system when each wind turbine to be processed outputs the optimized power is obtained, and the output inertia of each wind turbine to be processed is controlled according to the frequency change rate of the power system.

2. A direct-drive wind turbine inertia control method as claimed in claim 1, characterized in that: The method of controlling the output inertia of each wind turbine to be processed according to the frequency change rate of the power system includes: If the frequency change rate is not less than the maximum frequency change rate of the power system, the output inertia of each wind turbine to be processed is controlled to be the first inertia; wherein the first inertia is the initial output inertia of the wind turbine to be processed; If the frequency change rate is less than the maximum frequency change rate of the power system, obtaining the rotation speed of each wind turbine to be processed when the frequency change rate is less than the maximum frequency change rate of the power system; For each fan to be processed, when the rotation speed is less than the minimum rotation speed limit, the output inertia of the current fan to be processed is controlled to be zero; When the rotation speed is not less than the minimum rotation speed limit, if the rotation speed is less than the optimal rotation speed value, the output inertia of the fan to be processed is controlled to be the second inertia; wherein the second inertia is the maximum rotation speed frequency change value; If the rotation speed is greater than the optimal rotation speed value, the output inertia of the fan to be processed is controlled to be the third inertia; wherein the third inertia is the required rotation speed frequency change value.

3. A direct-drive wind turbine inertia control method as claimed in claim 2, characterized in that: For each fan to be processed, when the rotation speed is less than the minimum rotation speed limit, before controlling the output inertia of the current fan to be processed to zero, the method further includes: If the frequency change rate is less than the maximum frequency change rate of the power system, the system inertia requirement is determined according to the system demand power, the optimized power and the maximum frequency change rate.

4. A direct-drive wind turbine inertia control method as claimed in claim 3, characterized in that: The determining of the system inertia requirement according to the system required power, the optimized power and the maximum frequency change rate comprises: Determining the system power deficit according to the system required power and the optimized power; The system inertia requirement is determined according to the maximum frequency change rate and the system power shortage.

5. A direct-drive wind turbine inertia control method as claimed in claim 3, characterized in that: The third inertia is determined according to the inertia time constant of the fan rotor, the angular velocity of the fan and the system inertia requirement.

6. A direct-drive wind turbine inertia control method as claimed in claim 1, characterized in that: The objective function is specifically: Among them, F i is the mapping between the rotor kinetic energy and the captured power of the i-th wind turbine to be processed; P i is the power allocated to the i-th fan to be processed; n is the total number of fans to be processed.

7. A direct-drive wind turbine inertia control method as claimed in claim 1, characterized in that: The power balance constraint is specifically: The power limit constraint is specifically: Among them, P i is the power allocated to the i-th wind turbine to be processed; n is the total number of wind turbines to be processed; ω i is the angular velocity of the i-th fan; β i is the pitch angle of the i-th wind turbine; is the minimum output power of the fan; The maximum output power of the fan.

8. A direct-drive wind turbine inertia control device, characterized in that: include: Data acquisition module, objective function and constraint building module, objective function solving module, power control module and inertia control module; The data acquisition module is used to acquire a number of wind turbines capable of overspeed and load reduction operation in the wind power cluster of the power system as a number of wind turbines to be processed, and acquire wind power data of the power system; wherein the wind power data includes: the angular velocity of each wind turbine, the pitch angle of each wind turbine, the maximum output power of the wind turbine, the minimum output power of the wind turbine, and the mapping relationship between the output power of each wind turbine and the rotor kinetic energy; The objective function and constraint building module is used to build an objective function based on the wind power data with the goal of maximizing the rotor kinetic energy; and to build a power balance constraint and a power over-limit constraint of the objective function based on the wind power data; The objective function solving module is used to solve the objective function under the constraints of the power balance constraint and the power over-limit constraint to generate the optimized power of each wind turbine to be processed when the rotor kinetic energy is maximized; The power control module is used to control each wind turbine to be processed to output the optimized power; The inertia control module is used to obtain the frequency change rate of the power system when each wind turbine to be processed outputs the optimized power, and control the output inertia of each wind turbine to be processed according to the frequency change rate of the power system.

9. A terminal device, characterized in that: The invention comprises a processor, a memory and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, a direct-drive wind turbine inertia control method as claimed in any one of claims 1 to 7 is implemented.

10. A storage medium, characterized in that: The storage medium includes a stored computer program, wherein when the computer program is running, the device where the storage medium is located is controlled to execute the inertia control method of a direct-drive wind turbine set according to any one of claims 1 to 7.

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