Power distribution method and device for wind power plant overspeed variable pitch collaborative load shedding and electronic equipment

Abstract

The invention relates to the technical field of wind power plant frequency modulation power control, and provides a power distribution method and device for wind power plant overspeed variable pitch collaborative load shedding and electronic equipment. The power distribution method for wind power plant overspeed variable-pitch cooperative load shedding comprises the steps of obtaining structure parameters, wind speed information, pitch angle information and variable-pitch frequency modulation response time limit values of fans in a wind power plant and operation load shedding rate requirements of the wind power plant; based on the acquired data, constructing a linear programming problem by taking the variable quantity of the pitch angle of the fan in the wind power plant as an optimization variable; according to an optimization result of the linear programming problem, determining a pitch angle variable quantity of a fan in the wind power plant; and outputting a power reference value of the fan in the wind power plant based on the determined pitch angle variable quantity. According to the method, finer power distribution is achieved, meanwhile, the calculation time needed by the linear programming problem is short, and online application of the method in a wind power plant is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of wind farm frequency modulation power control, and in particular to a power distribution method, device and electronic equipment for coordinated load reduction of wind farm overspeed pitch change. Background Art

[0002] With the continuous increase in the proportion of wind power installed capacity, wind power participating in power system frequency regulation has become a general trend, and load reduction control is an important technical route. The load reduction control of wind turbines is mainly divided into overspeed control and pitch angle control. Since pitch angle control will cause wear to the wind turbine, overspeed control is generally used for load reduction. However, due to the limitation of the upper limit of the wind turbine rotor speed, there is an upper limit on the capacity of wind turbine overspeed load reduction. When the overspeed load reduction of wind turbines in a wind farm cannot meet the load reduction rate requirements of the wind farm, it is necessary to further perform pitch load reduction on the basis of overspeed load reduction, that is, overspeed pitch coordinated load reduction. The existing method sets the same load reduction power for all wind turbines to be pitched in the wind farm, and the pitch angle of each wind turbine is determined by its actual operating power. However, this method does not fully take into account the differences between different wind turbines in the wind farm, which may cause unnecessary wear or stress to some wind turbines, and may also affect the overall frequency regulation effect of the wind farm. Summary of the invention

[0003] The present invention provides a power distribution method, device and electronic equipment for coordinated load reduction of overspeed pitch change in a wind farm, which is used to solve the defect that the prior art does not fully take into account the differences between different wind turbines in a wind farm, which may cause unnecessary wear or stress to some wind turbines, and realizes more refined power distribution. At the same time, the calculation time required for linear programming problems is shorter, which is conducive to its online application in wind farms.

[0004] The present invention provides a power allocation method for coordinated load reduction by overspeed pitch change in a wind farm, comprising: obtaining structural parameters, wind speed information, pitch angle information, pitch change frequency regulation response time limit and operating load reduction rate requirements of wind turbines in the wind farm; based on the acquired data, taking the pitch angle variation of the wind turbines in the wind farm as an optimization variable, constructing a linear programming problem, wherein the constraints of the linear programming problem include that the total power of the wind turbines in the wind farm meets the operating load reduction rate requirements and the pitch angle variation of the wind turbines in the wind farm meets the inequality requirements; determining the pitch angle variation of the wind turbines in the wind farm according to the optimization result of the linear programming problem; and outputting power reference values ​​of the wind turbines in the wind farm based on the determined pitch angle variation.

[0005] According to the power allocation method for coordinated load reduction of overspeed pitch change in a wind farm provided by the present invention, based on the acquired data, the pitch angle change of the wind turbines in the wind farm is used as an optimization variable to construct a linear programming problem, including: calculating the maximum output power of each wind turbine based on the structural parameters and wind speed information of each wind turbine in the wind farm; dividing the wind turbines in the wind farm based on the calculated maximum output power, dividing the wind turbines capable of maximum power point tracking into medium wind speed zone wind turbines, dividing the wind turbines with higher wind speed into high wind speed zone wind turbines, and dividing the wind turbines with lower wind speed into low wind speed zone wind turbines; assuming that the pitch angle of the wind turbine in the high wind speed zone All of them are adjusted to the upper limit of the feasible domain, and it is determined whether the load reduction rate of the wind farm at this time is less than the preset load reduction rate; if the load reduction rate of the wind farm at this time is less than the preset load reduction rate, the wind turbine in the high wind speed area is set as the wind turbine to be changed; if the load reduction rate of the wind farm at this time is still less than the preset load reduction rate, the wind turbine in the high wind speed area is set as the wind turbine to be changed, and the wind turbines in the medium wind speed area are sorted in order from large to small wind speed, and the wind turbines in the medium wind speed area are set as the wind turbine to be changed in sequence according to the sorting results, until the total load reduction of the wind turbine to be changed can meet the load reduction demand of the wind farm; the pitch angle change of the wind turbine to be changed is taken as the optimization variable, and a linear programming problem is constructed.

[0006] According to the power allocation method for coordinated load reduction of overspeed pitch change in a wind farm provided by the present invention, the objective function of the linear programming problem includes minimizing the total pitch angle change of the wind turbine to be pitched; the total power of the wind turbines in the wind farm includes the power of the wind turbine to be pitched and the power of the wind turbines other than the wind turbines to be pitched in the wind farm.

[0007] According to the power allocation method for coordinated load reduction of overspeed pitch change in a wind farm provided by the present invention, based on the acquired data, the pitch angle change of the wind turbine in the wind farm is used as an optimization variable to construct a linear programming problem, including: judging whether the initial power of the wind turbine to be pitched is greater than the difference between the total power of the wind turbines in the wind farm that meets the operating load reduction rate requirement and the power of the wind turbines other than the wind turbines to be pitched in the wind farm; if the initial power of the wind turbine to be pitched is greater than the difference between the total power of the wind turbines in the wind farm that meets the operating load reduction rate requirement and the power of the wind turbines other than the wind turbines to be pitched in the wind farm, then the actual feasible domain of the pitch angle change is the first feasible domain, and the first feasible domain is 0 to The difference between the upper limit value of the pitch angle and the current pitch angle is connected by a line between two points corresponding to the boundary of the first feasible domain to obtain a first linear approximate relationship between the wind energy conversion efficiency coefficient and the pitch angle in the first feasible domain; if the initial power of the wind turbine to be pitched is not greater than the difference between the total power of the wind turbines in the wind farm that meets the operating load reduction rate requirement and the power of the non-wind turbines to be pitched in the wind farm, then the actual feasible domain of the pitch angle change is the second feasible domain, and the second feasible domain is the difference between the basic pitch angle and the current pitch angle to 0, and the two points corresponding to the boundary of the second feasible domain are connected to obtain a second linear approximate relationship between the wind energy conversion efficiency coefficient and the pitch angle in the second feasible domain.

[0008] According to the power allocation method for overspeed pitch change and coordinated load reduction in a wind farm provided by the present invention, the pitch angle change of at most one wind turbine in the optimization result is not on the boundary of the pitch angle inequality constraint; and adjusting the pitch angle change of the wind turbines in the wind farm according to the optimization result of the linear programming problem includes adjusting the pitch angle change of at most one wind turbine.

[0009] According to the power allocation method for coordinated load reduction of overspeed pitch change in a wind farm provided by the present invention, the power reference value of the wind turbine in the wind farm is output based on the determined pitch angle change, comprising: substituting the determined pitch angle change into a power expression to calculate the power reference value of the wind turbine to be pitched; setting the power reference value of the wind turbine in the low wind speed zone to the maximum output power; and substituting a pitch angle of zero into the power expression to calculate the power reference value of the wind turbine in the high wind speed zone and the wind turbine in the medium wind speed zone that is not to be pitched.

[0010] The present invention also provides a power distribution device for coordinated load reduction by overspeed pitch change in a wind farm, comprising: an acquisition module, configured to acquire structural parameters, wind speed information, pitch angle information, pitch frequency regulation response time limit and operating load reduction rate requirements of wind turbines in the wind farm; an optimization module, configured to construct a linear programming problem based on the acquired data, taking the pitch angle change of the wind turbines in the wind farm as an optimization variable, wherein the constraints of the linear programming problem include that the total power of the wind turbines in the wind farm satisfies the operating load reduction rate requirements and that the pitch angle change of the wind turbines in the wind farm satisfies the inequality requirements; a determination module, configured to determine the pitch angle change of the wind turbines in the wind farm according to the optimization result of the linear programming problem; and an output module, configured to output power reference values ​​of the wind turbines in the wind farm based on the determined pitch angle change.

[0011] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, a power distribution method for coordinated load reduction of overspeed pitch change in a wind farm as described in any one of the above-mentioned methods is implemented.

[0012] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the power distribution method for coordinated load reduction by overspeed pitch change in a wind farm as described in any one of the above.

[0013] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the power allocation method for coordinated load reduction by overspeed pitch change in a wind farm as described in any one of the above methods is implemented.

[0014] The power allocation method, device and electronic equipment for coordinated load reduction of overspeed variable pitch in a wind farm provided by the present invention take the pitch angle change of the wind turbines in the wind farm as the optimization variable based on the data of the wind turbines in the wind farm and the operating load reduction rate requirements of the wind farm, construct a linear programming problem, and achieve more refined power allocation. At the same time, the calculation time required for the linear programming problem is shorter, which is conducive to its online application in wind farms. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is a flow chart of a power distribution method for coordinated load reduction by overspeed pitch change in a wind farm provided by the present invention.

[0017] Figure 2 It is a schematic diagram of a system model composed of a wind farm, a thermal power plant and a load provided by the present invention.

[0018] Figure 3 It is a schematic diagram of the wind speed distribution of wind turbines in a wind farm provided by the present invention.

[0019] Figure 4 It is a structural schematic diagram of a power distribution device for coordinated load reduction by overspeed pitch change in a wind farm provided by the present invention.

[0020] Figure 5 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are 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.

[0022] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one", "one" or "the" do not indicate a quantitative limitation, but indicate the existence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0023] The following is a brief explanation of the terms involved in the present invention.

[0024] Combine the following Figure 1-Figure 5 The invention describes a power distribution method, device and electronic equipment for coordinated load reduction by overspeed pitch change in a wind farm.

[0025] Figure 1 : is a flow chart of the power allocation method for wind farm overspeed pitch-changing coordinated load reduction provided by the present invention, such as Figure 1 As shown, the method includes the following: Step 101: Obtain structural parameters, wind speed information, pitch angle information, variable pitch frequency response time limit, and load reduction rate requirements of wind turbines in a wind farm.

[0026] In this embodiment, the structural parameters of the fan may include the blade radius ; Gearbox ratio ; Speed ​​upper limit ; Inertia time constant etc. Wind speed information may include wind speed ; Air density etc.; the pitch angle information may include the basic pitch angle ; Current pitch angle ; Upper limit of pitch angle The load reduction rate requirements for wind farms can include the load reduction rate that the wind farm as a whole needs to achieve. (Ratio of load shedding reserve capacity to actual output power).

[0027] Step 102: Based on the acquired data, the pitch angle variation of the wind turbines in the wind farm is used as an optimization variable to construct a linear programming problem.

[0028] In this embodiment, in the linear programming problem, the objective function can be set based on considerations such as minimizing cost, minimizing wear, balancing wear and cost, etc. The constraints of the linear programming problem can also include safety and stability constraints, economic constraints, etc., which can be selected and constructed according to actual needs. By optimizing the change in pitch angle, the power output of the wind turbine can be controlled more accurately, thereby improving the response speed and frequency regulation capability of the wind farm to changes in the frequency of the power system. Compared with using the particle swarm optimization algorithm to solve the original pitch angle optimization problem, the linear programming problem has higher computational efficiency, and linear programming can ensure that the global optimal solution is found when certain conditions are met (such as the objective function and the constraints are linear). Although the particle swarm optimization algorithm has global search capabilities, it may converge to a local optimal solution.

[0029] Step 103: Determine the pitch angle variation of the wind turbines in the wind farm according to the optimization result of the linear programming problem.

[0030] In this embodiment, a linear programming solver (such as the simplex method, the interior point method, etc.) may be used to find an optimal solution to determine the pitch angle change of the wind turbines in the wind farm.

[0031] Step 104: outputting a power reference value of the wind turbine in the wind farm based on the determined pitch angle variation.

[0032] In this embodiment, the pitch angle change of each wind turbine can be determined according to the solution of the linear programming. The new pitch angle of each wind turbine can be calculated using the pitch angle change in the optimization result, and the power reference value of each wind turbine can be calculated using the wind energy conversion efficiency coefficient and other related parameters, which can then be sent to each wind turbine as a power command.

[0033] The power allocation method for coordinated load reduction by overspeed pitch change in a wind farm provided by the present invention takes the pitch angle change of the wind turbines in the wind farm as the optimization variable based on the data of the wind turbines in the wind farm and the operating load reduction rate requirements of the wind farm, constructs a linear programming problem, and realizes more refined power allocation. At the same time, the calculation time required for the linear programming problem is shorter, which is conducive to its online application in the wind farm.

[0034] In some optional implementations, based on the acquired data, the pitch angle variation of the wind turbines in the wind farm is used as an optimization variable to construct a linear programming problem, including: calculating the maximum output power of each wind turbine based on the structural parameters and wind speed information of each wind turbine in the wind farm; ; Based on the calculated maximum output power, the wind turbines in the wind farm can be divided, and the wind turbines that can perform maximum power point tracking are divided into medium wind speed zone wind turbines, wind turbines with higher wind speeds are divided into high wind speed zone wind turbines, and wind turbines with lower wind speeds are divided into low wind speed zone wind turbines; assuming that the pitch angles of the wind turbines in the high wind speed zone are all adjusted to the upper limit of the feasible domain, determine whether the load reduction rate of the wind farm at this time is less than the preset load reduction rate; if the load reduction rate of the wind farm at this time is less than the preset load reduction rate, the wind turbines in the high wind speed zone are set as the wind turbines to be pitched; if the load reduction rate of the wind farm at this time is still less than the preset load reduction rate, the wind turbines in the high wind speed zone are set as the wind turbines to be pitched, and the wind turbines in the medium wind speed zone are sorted in order from large to small wind speeds, and the wind turbines in the medium wind speed zone are set as the wind turbines to be pitched according to the sorting results, until the total load reduction of the wind turbines to be pitched can meet the load reduction demand of the wind farm; the pitch angle change of the wind turbines to be pitched is taken as the optimization variable, and a linear programming problem is constructed.

[0035] The unit load reduction power of a wind turbine is proportional to the cube of the wind speed, so for wind turbines with high wind speeds, the load reduction power brought by a unit change in pitch angle is greater. In addition, compared with wind turbines in medium and low wind speed zones, wind turbines with high wind speeds have higher power when not reduced, so the load reduction potential is also greater. Therefore, variable pitch angle control should be performed on wind turbines in high wind speed zones in wind farms as a priority. However, if there are not many wind turbines in high wind speed zones, the load reduction capacity that can be provided is limited and cannot meet the load reduction requirements of the wind farm, wind turbines in medium wind speed zones are still required to participate in variable pitch angle control.

[0036] The feasible domain of wind turbine pitch angle is: in, for The pitch angle change of wind turbine No.

[0037] Based on the above analysis, the wind turbines to be adjusted in pitch can be determined through classified discussion: Assuming that the pitch angles of the wind turbines in the high wind speed zone are all adjusted to the upper limit of the feasible domain, if the load reduction rate of the wind farm is not less than the preset load reduction rate at this time, it means that only the wind turbines in the high wind speed zone can meet the load reduction demand of the wind farm by changing the pitch, and then only the wind turbines in the high wind speed zone are set as the wind turbines to be adjusted in pitch. Assuming that the pitch angles of the wind turbines in the high wind speed zone are all adjusted to the upper limit of the feasible domain, if the load reduction rate of the wind farm is still less than the preset load reduction rate at this time, it means that only the wind turbines in the high wind speed zone cannot meet the load reduction demand of the wind farm by changing the pitch. At this time, it is necessary to sort the wind turbines in the medium wind speed zone in order from high to low wind speed, and set them as wind turbines to be adjusted in pitch in turn, until the total load reduction of all wind turbines to be adjusted in pitch can meet the load reduction demand of the wind farm.

[0038] In some optional implementations, the objective function of the linear programming problem includes minimizing the total pitch angle change of the wind turbines to be changed; the total power of the wind turbines in the wind farm includes the power of the wind turbines to be changed and the power of the wind turbines not to be changed in the wind farm. The variable pitch angle control of the wind turbine will cause mechanical wear and affect the service life of the wind turbine. Therefore, in order to reduce the impact of the variable pitch angle control on the life of the wind turbine, the pitch angle change should be minimized, so the objective function of the optimization problem is: in, A collection of wind turbines to be pitched.

[0039] Under certain working conditions, the wind turbines in the low wind speed zone do not participate in frequency modulation, and the power is a constant value; for the wind turbines in the medium wind speed zone that do not participate in variable pitch angle control, their rotor speeds have reached the upper limit, the pitch angle is 0, and the power is also a constant value. Therefore, the total power of the wind turbines to be variable pitch is the total output power of the wind farm minus the above two constant values, and the power equation constraint is: in, ; ; for Radius of fan blades; for No. fan wind speed; for No. fan gearbox ratio; for Maximum output power of fan No. when running without load reduction, It is a collection of fans in low wind speed area.

[0040] Since the wind energy conversion efficiency coefficient It follows Monotonically decreasing, so when the initial power satisfies When the optimization result is , then the objective function is equivalent to: .

[0041] Similarly, when the initial power meets When the optimization result is , then the objective function is equivalent to: .

[0042] In some optional implementations, based on the acquired data, the pitch angle change of the wind turbines in the wind farm is used as an optimization variable to construct a linear programming problem, including: judging whether the initial power of the wind turbine to be pitched is greater than the difference between the total power of the wind turbines in the wind farm that meet the requirements of the operating load reduction rate and the power of the wind turbines not to be pitched in the wind farm; if the initial power of the wind turbine to be pitched is greater than the difference between the total power of the wind turbines in the wind farm that meet the requirements of the operating load reduction rate and the power of the wind turbines not to be pitched in the wind farm, then the actual feasible domain of the pitch angle change is the first feasible domain, and the first feasible domain is 0 to the upper limit of the pitch angle and the current pitch The difference between the basic pitch angle and the current pitch angle is obtained by connecting the two points corresponding to the boundary of the first feasible domain, and the first linear approximate relationship between the wind energy conversion efficiency coefficient and the pitch angle in the first feasible domain is obtained; if the initial power of the wind turbine to be pitched is not greater than the difference between the total power of the wind turbines in the wind farm that meets the requirements of the operating load reduction rate and the power of the non-pitch wind turbines to be pitched in the wind farm, then the actual feasible domain of the pitch angle change is the second feasible domain, and the second feasible domain is the difference between the basic pitch angle and the current pitch angle to 0. Connect the two points corresponding to the boundary of the second feasible domain, and the second linear approximate relationship between the wind energy conversion efficiency coefficient and the pitch angle in the second feasible domain is obtained. When the initial power of the wind turbine to be pitched satisfies When , the actual feasible range of pitch angle variation is: By connecting the two points corresponding to the boundary of the feasible region of the inequality, the linear approximate relationship between the wind energy conversion efficiency coefficient and the pitch angle in the feasible region of the inequality can be obtained, and the expression is: in, , the power equality constraint can be simplified to: When the initial power of the variable pitch wind turbine meets When , the actual feasible range of pitch angle variation is: By connecting the two points corresponding to the boundary of the feasible region of the inequality, the linear approximate relationship between the wind energy conversion efficiency coefficient and the pitch angle in the feasible region of the inequality can be obtained, and the expression is: in, , the power equality constraint can be simplified to: .

[0043] By combining the simplified objective function, pitch angle inequality constraint and simplified power equality constraint, a linear programming problem is constructed in different cases. When , the linear programming problem is: When the initial power of the variable pitch wind turbine meets When , the linear programming problem is: In both cases, this is a standard form of linear programming problem, for which there are existing mathematical methods to solve the overall optimization problem, or to call solvers in commercial software to solve it. The solution time of this optimization problem is much shorter than the complex optimization problem of non-convex nonlinear in the existing methods.

[0044] In some optional implementations, in the optimization result, the pitch angle change of at most one wind turbine is not on the boundary of the pitch angle inequality constraint; adjusting the pitch angle change of the wind turbines in the wind farm according to the optimization result of the linear programming problem includes adjusting the pitch angle change of at most one wind turbine. According to the mathematical properties of the linear programming problem, in the optimization result, the pitch angle change of at most one wind turbine is not on the boundary of the pitch angle inequality constraint.

[0045] Since the specific method of linear approximation is "connecting two points on the boundary of the feasible region", the linear approximation of the wind energy conversion efficiency coefficient does not bring errors to the original power equation constraint for the vast majority of wind turbines whose pitch angle variation is on the boundary. At most, only one wind turbine whose pitch angle variation is not on the boundary brings errors to the original power equation constraint. Therefore, it is only necessary to adjust the pitch angle variation of this wind turbine to make the original power equation constraint hold. The original power equation is: Since only the pitch angle change of this wind turbine needs to be adjusted, this is a single-variable equation, which can be solved using existing mathematical methods. According to the existing algorithms and computing power level, the solution time of this single-variable equation is extremely short.

[0046] In some optional implementations, the power reference value of the wind turbines in the wind farm is output based on the determined pitch angle change, including: substituting the determined pitch angle change into the power expression to calculate the power reference value of the wind turbine to be pitched; setting the power reference value of the wind turbine in the low wind speed zone to the maximum output power; substituting the pitch angle of zero into the power expression to calculate the power reference value of the wind turbines in the high wind speed zone and the wind turbines in the medium wind speed zone that are not to be pitched. The wind turbines in the low wind speed zone are not deloaded, and the power reference value is the maximum output power .

[0047] The power reference value of the variable pitch wind turbine is: The power reference values ​​of other fans are: The obtained power reference value can be sent to each fan as a power command.

[0048] In order to verify the application effect of the above implementation method, a Figure 2 The system model consisting of wind farms, thermal power plants and loads is shown. Figure 2 The medium wind farm contains 30 double-fed wind turbines with a rated capacity of 5MW (typical wind turbines), and the thermal power plant contains 5 thermal power units with a rated capacity of 60MW, with a total load of 300MW. Among them, the inertia time constant of the three double-fed wind turbines is 7s, the inertia time constant of the thermal power unit is 10s, and the power frequency static characteristic coefficient of the thermal power unit is 20; load and The load frequency regulation effect coefficient is 3. The wind speed distribution of the 30 wind turbines is as follows: Figure 3 As shown in Figure 1, each wind speed zone has corresponding wind turbines operating in the wind farm. The total load reduction power of the wind farm is set to 6% of the operating power.

[0049] Refer to Table 1 for the calculation results of the three variable pitch load reduction power distribution methods, and compare the method provided by the above-mentioned implementation method of the present invention with the use of the particle swarm optimization algorithm to solve the original pitch angle optimization problem, and calculate the power reference value of the wind turbine to be changed according to the pitch angle optimization result, as well as the traditional method, that is, setting the same load reduction power for all wind turbines to be changed in the wind farm, and the pitch angle of each wind turbine is determined by its actual operating power.

[0050] Compared with the particle swarm method, the pitch angle optimization results obtained by the method of the present invention and the particle swarm method are very similar, but under the same computing power, the calculation time of the method of the present invention is in the order of hundreds of ms, which is much shorter than the min level of the particle swarm method. Compared with the traditional method, the calculation time of both is in the order of hundreds of ms, but the total change of the pitch angle obtained by the method of the present invention is much smaller than that of the traditional method, and the mechanical wear of the wind turbine caused by variable pitch load reduction is significantly less than that of the traditional method. Based on the above analysis, the method of the present invention can not only greatly shorten the calculation time of the optimization problem, but also accurately meet the operating load reduction rate requirements of the wind farm, and significantly reduce the total change of the pitch angle of the wind farm, which is conducive to the realization of online application in actual wind farms.

[0051] The power distribution device for coordinated load reduction of wind farm overspeed pitch change provided by the present invention is described below. The power distribution device for coordinated load reduction of wind farm overspeed pitch change described below and the power distribution method for coordinated load reduction of wind farm overspeed pitch change described above can be referred to each other.

[0052] Figure 4 The schematic diagram of the structure of the power distribution device for wind farm overspeed pitch coordination load reduction provided by the embodiment of the present application is as follows: Figure 4 As shown, it specifically includes: an acquisition module 401, which is configured to acquire structural parameters, wind speed information, pitch angle information, variable pitch frequency response time limit and operation load reduction rate requirements of wind turbines in the wind farm; an optimization module 402, which is configured to construct a linear programming problem based on the acquired data, taking the pitch angle change of the wind turbines in the wind farm as an optimization variable, and the constraints of the linear programming problem include that the total power of the wind turbines in the wind farm meets the operation load reduction rate requirements; a determination module 403, which is configured to determine the pitch angle change of the wind turbines in the wind farm according to the optimization result of the linear programming problem; and an output module 404, which is configured to output the power reference value of the wind turbines in the wind farm based on the determined pitch angle change.

[0053] In some optional implementations, the optimization module 402 is further configured to: calculate the maximum output power of each wind turbine in the wind farm based on the structural parameters and wind speed information of each wind turbine in the wind farm; divide the wind turbines in the wind farm based on the calculated maximum output power, and divide the wind turbines capable of maximum power point tracking into medium wind speed zone wind turbines, wind turbines with higher wind speeds into high wind speed zone wind turbines, and wind turbines with lower wind speeds into low wind speed zone wind turbines; assuming that the pitch angles of the wind turbines in the high wind speed zone are all adjusted to the upper limit of the feasible domain, it is determined that the wind farm is unloaded at this time. Whether the load reduction rate is less than the preset load reduction rate; if the load reduction rate of the wind farm is less than the preset load reduction rate, the wind turbine in the high wind speed area is set as the wind turbine to be changed; if the load reduction rate of the wind farm is still less than the preset load reduction rate, the wind turbine in the high wind speed area is set as the wind turbine to be changed, and the wind turbines in the medium wind speed area are sorted in order from large to small wind speed, and the wind turbines in the medium wind speed area are set as the wind turbine to be changed in sequence according to the sorting results, until the total load reduction of the wind turbine to be changed can meet the load reduction demand of the wind farm; the pitch angle change of the wind turbine to be changed is taken as the optimization variable, and a linear programming problem is constructed.

[0054] In some optional implementations, the objective function of the linear programming problem includes minimizing the total pitch angle change of the wind turbines to be pitched; the total power of the wind turbines in the wind farm includes the power of the wind turbines to be pitched and the power of the non-wind turbines to be pitched in the wind farm.

[0055] In some optional implementations, the optimization module 402 is further configured to: determine whether the initial power of the wind turbine to be pitched is greater than the difference between the total power of the wind turbines in the wind farm that meet the requirements of the operating load reduction rate and the power of the wind turbines not to be pitched in the wind farm; if the initial power of the wind turbine to be pitched is greater than the difference between the total power of the wind turbines in the wind farm that meet the requirements of the operating load reduction rate and the power of the wind turbines not to be pitched in the wind farm, then the actual feasible domain of the pitch angle change is the first feasible domain, the first feasible domain is 0 to the difference between the upper limit value of the pitch angle and the current pitch angle, and the boundary of the first feasible domain is The corresponding two points are connected to obtain the first linear approximate relationship between the wind energy conversion efficiency coefficient and the pitch angle in the first feasible domain; if the initial power of the wind turbine to be pitched is not greater than the difference between the total power of the wind turbines in the wind farm that meets the operating load reduction rate requirements and the power of the non-pitch wind turbines to be pitched in the wind farm, then the actual feasible domain of the pitch angle change is the second feasible domain, and the second feasible domain is the difference between the basic pitch angle and the current pitch angle to 0. The two points corresponding to the boundary of the second feasible domain are connected to obtain the second linear approximate relationship between the wind energy conversion efficiency coefficient and the pitch angle in the second feasible domain.

[0056] In some optional implementations, the pitch angle change of at most one wind turbine in the optimization result is not on the boundary of the pitch angle inequality constraint; the pitch angle change of the wind turbines in the wind farm is adjusted according to the optimization result of the linear programming problem, including adjusting the pitch angle change of at most one wind turbine.

[0057] In some optional implementations, the output module 404 is further configured to: substitute the determined pitch angle change into the power expression to calculate the power reference value of the wind turbine to be pitched; set the power reference value of the wind turbine in the low wind speed zone to the maximum output power; substitute the pitch angle of zero into the power expression to calculate the power reference value of the wind turbine in the high wind speed zone and the wind turbine in the medium wind speed zone that is not to be pitched.

[0058] The power distribution device for coordinated load reduction of overspeed variable pitch in a wind farm provided by the present invention takes the pitch angle change of the wind turbines in the wind farm as the optimization variable based on the data of the wind turbines in the wind farm and the operating load reduction rate requirements of the wind farm, constructs a linear programming problem, and realizes more refined power distribution. At the same time, the calculation time required for the linear programming problem is shorter, which is conducive to its online application in the wind farm.

[0059] Figure 5 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 5 As shown, the electronic device may include: a processor 510, a communication interface 520, a memory 530 and a communication bus 540, wherein the processor 510, the communication interface 520 and the memory 530 communicate with each other through the communication bus 540. The processor 510 may call the logic instructions in the memory 530 to execute the power allocation method for overspeed pitch-changing coordinated load reduction in a wind farm, the method comprising: obtaining the structural parameters, wind speed information, pitch angle information, pitch-changing frequency modulation response time limit and the load reduction rate requirement of the wind farm in the wind farm; based on the acquired data, taking the pitch angle variation of the wind turbine in the wind farm as the optimization variable, constructing a linear programming problem, the constraints of the linear programming problem including that the total power of the wind turbine in the wind farm meets the load reduction rate requirement; determining the pitch angle variation of the wind turbine in the wind farm according to the optimization result of the linear programming problem; and outputting the power reference value of the wind turbine in the wind farm based on the determined pitch angle variation.

[0060] In addition, the logic instructions in the above-mentioned memory 530 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0061] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the power allocation method for overspeed pitch change and coordinated load reduction in a wind farm provided by the above methods. The method includes: obtaining structural parameters, wind speed information, pitch angle information, pitch change and frequency regulation response time limit of wind turbines in the wind farm, and operating load reduction rate requirements of the wind farm; based on the acquired data, taking the pitch angle change of the wind turbines in the wind farm as an optimization variable, constructing a linear programming problem, the constraints of the linear programming problem include that the total power of the wind turbines in the wind farm meets the operating load reduction rate requirements; determining the pitch angle change of the wind turbines in the wind farm according to the optimization results of the linear programming problem; and outputting power reference values ​​of the wind turbines in the wind farm based on the determined pitch angle change.

[0062] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the power allocation method for overspeed pitch change and coordinated load reduction in a wind farm provided by the above-mentioned methods, the method comprising: obtaining structural parameters, wind speed information, pitch angle information, pitch change and frequency regulation response time limit of wind turbines in the wind farm, and operating load reduction rate requirements of the wind farm; based on the acquired data, taking the pitch angle change of the wind turbines in the wind farm as an optimization variable, constructing a linear programming problem, the constraints of the linear programming problem including that the total power of the wind turbines in the wind farm meets the operating load reduction rate requirements; determining the pitch angle change of the wind turbines in the wind farm according to the optimization result of the linear programming problem; and outputting a power reference value of the wind turbines in the wind farm based on the determined pitch angle change.

[0063] The device embodiments described above are merely illustrative, 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. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0064] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A power allocation method for coordinated load reduction of wind farm overspeed pitch control, characterized in that: include: Obtaining structural parameters, wind speed information, pitch angle information, variable pitch frequency response time limit of wind turbines in the wind farm, and operating load reduction rate requirements of the wind farm; Based on the acquired data, a pitch angle variation of the wind turbines in the wind farm is used as an optimization variable to construct a linear programming problem, wherein the constraints of the linear programming problem include that the total power of the wind turbines in the wind farm meets the operating load reduction rate requirement and that the pitch angle variation of the wind turbines in the wind farm meets the inequality requirement; Determining a pitch angle variation of a wind turbine in the wind farm according to an optimization result of a linear programming problem; A power reference value of the wind turbine in the wind farm is output based on the determined pitch angle variation.

2. The power allocation method for wind farm overspeed pitch change coordinated load reduction according to claim 1 is characterized in that: Based on the acquired data, the pitch angle variation of the wind turbines in the wind farm is used as an optimization variable to construct a linear programming problem, including: Calculating the maximum output power of each wind turbine based on the structural parameters and wind speed information of each wind turbine in the wind farm; Based on the calculated maximum output power, the wind turbines in the wind farm are divided into wind turbines capable of maximum power point tracking as wind turbines in a medium wind speed zone, wind turbines with higher wind speeds as wind turbines in a high wind speed zone, and wind turbines with lower wind speeds as wind turbines in a low wind speed zone; Assuming that the pitch angles of the wind turbines in the high wind speed area are all adjusted to the upper limit of the feasible region, it is determined whether the load reduction rate of the wind farm is less than the preset load reduction rate at this time; If the load reduction rate of the wind farm is less than the preset load reduction rate at this time, the wind turbine in the high wind speed area is set as a wind turbine to be pitched; If the load reduction rate of the wind farm is still less than the preset load reduction rate at this time, the wind turbines in the high wind speed area are set as the wind turbines to be pitched, and the wind turbines in the medium wind speed area are sorted in descending order of wind speed, and the wind turbines in the medium wind speed area are sequentially set as the wind turbines to be pitched according to the sorting results, until the total load reduction of the wind turbines to be pitched can meet the load reduction demand of the wind farm; The pitch angle variation of the wind turbine to be variable-pitch is used as an optimization variable to construct a linear programming problem.

3. The power allocation method for wind farm overspeed pitch change coordinated load reduction according to claim 2 is characterized in that: The objective function of the linear programming problem includes minimizing the total pitch angle change of the wind turbine to be pitched; the total power of the wind turbines in the wind farm includes the power of the wind turbine to be pitched and the power of the wind turbines other than the wind turbines to be pitched in the wind farm.

4. The power allocation method for wind farm overspeed pitch change coordinated load reduction according to claim 3 is characterized in that: Based on the acquired data, the pitch angle variation of the wind turbines in the wind farm is used as an optimization variable to construct a linear programming problem, including: Determine whether the initial power of the wind turbine to be pitch-changed is greater than the difference between the total power of wind turbines in the wind farm that meet the operation load reduction rate requirement and the power of wind turbines other than the wind turbine to be pitch-changed in the wind farm; If the initial power of the wind turbine to be pitched is greater than the difference between the total power of the wind turbines in the wind farm that meets the operating load reduction rate requirement and the power of the wind turbines other than the wind turbines to be pitched in the wind farm, the actual feasible domain of the pitch angle change is the first feasible domain, and the first feasible domain is the difference between 0 and the upper limit of the pitch angle and the current pitch angle. The two points corresponding to the boundary of the first feasible domain are connected to obtain a first linear approximate relationship between the wind energy conversion efficiency coefficient and the pitch angle in the first feasible domain; If the initial power of the wind turbine to be pitched is not greater than the difference between the total power of the wind turbines in the wind farm that meets the operating load reduction rate requirement and the power of the wind turbines other than the wind turbines to be pitched in the wind farm, then the actual feasible domain of the pitch angle change is the second feasible domain, and the second feasible domain is the difference between the basic pitch angle and the current pitch angle to 0. The two points corresponding to the boundary of the second feasible domain are connected to obtain a second linear approximate relationship between the wind energy conversion efficiency coefficient and the pitch angle in the second feasible domain.

5. The power allocation method for coordinated load reduction of wind farm overspeed pitch control according to claim 4 is characterized in that: In the optimization result, the pitch angle change of at most one wind turbine is not on the boundary of the pitch angle inequality constraint; and adjusting the pitch angle change of the wind turbines in the wind farm according to the optimization result of the linear programming problem includes adjusting the pitch angle change of at most one wind turbine.

6. The power allocation method for coordinated load reduction of wind farm overspeed pitch control according to claim 2 is characterized in that: The step of outputting a power reference value of a wind turbine in the wind farm based on the determined pitch angle variation comprises: Substituting the determined pitch angle variation into a power expression to calculate a power reference value of the wind turbine to be pitched; The power reference value of the wind turbine in the low wind speed zone is set to the maximum output power; Substituting a pitch angle of zero into a power expression is used to calculate power reference values ​​of the wind turbines in the high wind speed zone and the wind turbines in the medium wind speed zone that are not to be pitched.

7. A power distribution device for coordinated load reduction of wind farm overspeed pitch change, characterized in that: include: An acquisition module is configured to acquire structural parameters, wind speed information, pitch angle information, variable pitch frequency response time limit of wind turbines in the wind farm, and load reduction rate requirements for the wind farm; an optimization module configured to construct a linear programming problem based on the acquired data and taking the pitch angle variation of the wind turbines in the wind farm as an optimization variable, wherein the constraints of the linear programming problem include that the total power of the wind turbines in the wind farm meets the operation load reduction rate requirement and the pitch angle variation of the wind turbines in the wind farm meets the inequality requirement; A determination module is configured to determine the pitch angle variation of the wind turbines in the wind farm according to the optimization result of the linear programming problem; The output module is configured to output a power reference value of the wind turbine in the wind farm based on the determined pitch angle variation.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the power allocation method for coordinated load reduction by overspeed pitch change in a wind farm as claimed in any one of claims 1 to 6 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the power allocation method for coordinated load reduction by overspeed pitch change in a wind farm as claimed in any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the power allocation method for coordinated load reduction by overspeed pitch change in a wind farm as claimed in any one of claims 1 to 6 is implemented.

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