阅读说明：本技术 一种提高高海拔风电机组发电量的方法 (Method for improving generating capacity of high-altitude wind turbine generator system ) 是由 史晓鸣 柳黎明 吴明霞 陈靖 陈凯 陈坚钢 于 2019-11-13 设计创作，主要内容包括：本发明涉及风力发电技术领域,公开了一种提高高海拔风电机组发电量的方法,包括下列步骤：A)计算空气密度ρ；B)得到风电机组的C<Sub>P</Sub>-λ特性曲线；C)计算风电机组输出功率P和机组转矩T；D)设置风速调节范围,当风速υ在风速调节范围内时获得最优转矩T<Sub>opt1</Sub>；E)当机组转速调节范围达到风速调节范围上限时获得最优转矩T<Sub>opt2</Sub>；F)获得约束条件；G)构建目标函数,利用优化算法对目标函数进行寻优,获得使风电机组风能捕获输出功率最大和载荷最小的各机组转速组合。本发明使在高海拔地区机组叶尖速比也能达到实际最佳,使风能捕获系数最大,提高了风电机组的发电量,并利用优化算法实现风电场中各机组的功率最大捕获和载荷最小。(The invention relates to the technical field of wind power generation, and discloses a method for improving the generating capacity of a high-altitude wind turbine generator system, which comprises the following steps: A) calculating the air density rho; B) obtaining C of the wind turbine generator P -a characteristic curve; C) calculating the output power P and the torque T of the wind turbine generator; D) setting a wind speed regulation range, and obtaining an optimal torque T when the wind speed upsilon is within the wind speed regulation range opt1 (ii) a E) When the adjusting range of the rotating speed of the unit reaches the upper limit of the adjusting range of the wind speed, the optimal torque T is obtained opt2 (ii) a F) Obtaining a constraint condition; G) and constructing an objective function, and optimizing the objective function by using an optimization algorithm to obtain each set rotating speed combination which enables the wind energy capture output power of the wind turbine generator to be maximum and the load to be minimum. The invention can ensure that the speed ratio of the blade tip of the unit can also reach the actual best in the high-altitude area, the wind energy capture coefficient is maximized, the generated energy of the wind turbine generator is improved, and the maximum power capture and the minimum load of each unit in the wind power plant are realized by utilizing an optimization algorithm.)

1. A method for improving the generating capacity of a high-altitude wind turbine generator set is characterized by comprising the following steps:

A) acquiring atmospheric pressure p and extravehicular temperature t, and calculating air density rho;

B) obtaining the rotating speed omega of the generator_gAnd a wind wheel radius r, and obtaining a Cp-lambda characteristic curve of the wind turbine set through aerodynamic calculation, wherein C is the characteristic curve_pIs the power coefficient, and λ is the tip speed ratio;

C) obtaining a theoretical wind speed upsilon based on a tip speed ratio lambda, and calculating the output power P of the wind turbine generator and the torque T of the wind turbine generator;

D) setting a wind speed adjusting range, and obtaining the optimal torque T when the wind speed v is within the wind speed adjusting range_opt1Setting the unit torque T to the optimum torque T_opt1；

E) When the rotating speed adjusting range of the unit reaches the upper limit of the wind speed adjusting range, the optimal torque T is obtained_opt2Setting the unit torque T to the optimum torque T_opt2；

F) Setting an upper limit T of torque_maxAnd generator speed upper limit omega_gmaxObtaining a constraint conditionSet torque, ω, for the ith wind turbine_giThe number is the generator speed of the ith wind turbine generator, and K is the total number of the wind turbine generators;

G) and constructing an objective function, and optimizing the objective function by using an optimization algorithm to obtain each set rotating speed combination which enables the wind energy capture output power of the wind turbine generator to be maximum and the load to be minimum.

2. The method for improving the power generation capacity of the high-altitude wind turbine generator set according to claim 1, wherein the calculation in the step A) is carried outObtaining the air density rho, wherein M is the standard air molar mass and R is a gas constant.

3. High altitude wind turbine according to claim 1Method for generating electric power, characterized in that in step C) the electric power is generated by calculationA theoretical wind speed v based on the tip speed ratio λ is obtained, where G is the gearbox speed ratio.

4. The method for improving the power generation capacity of the high-altitude wind turbine generator set according to claim 3, wherein the calculation in the step C) is carried outAnd obtaining the output power P of the wind turbine generator, wherein A is the wind sweeping area of the impeller.

5. The method for improving the power generation capacity of the high-altitude wind turbine generator set according to claim 4, wherein the calculation in the step C) is carried outAnd obtaining the torque T of the unit.

6. The method for improving the power generation capacity of a high-altitude wind power generation unit according to claim 5, wherein the optimal torque T is obtained in the step D) when the wind speed v is within the wind speed regulation range_opt1The method comprises the following steps:

D1) for actual generator speed omega_gCompensating to obtain the actual optimal tip speed ratio lambda_optAnd the actual optimum tip speed ratio lambda_optCorresponding maximum power coefficient maximum C_pmax；

D2) Obtaining the tip speed ratio lambda reaching the actual optimal tip speed ratio lambda_optTheoretical rotational speed of the generatorWherein, the delta omega is a rotation speed compensation difference value;

D3) obtaining cut-in wind speed upsilon_inCut into a wind speed upsilon_outAnd rated wind speed upsilon_nWhen the wind speed is cut inWind velocity upsilon_inAnd rated wind speed upsilon_nI.e. v_in≤v≤v_nTime, calculateObtaining an optimum torque T_opt1。

7. The method for improving the power generation capacity of the high-altitude wind turbine generator set according to claim 6, wherein the optimal torque T is obtained in the step D)_opt2The method comprises the following steps:

when the wind speed is on rated wind speed upsilon_nAnd cut-in wind velocity upsilon_outIn the meantime, the rotating speed omega of the generator is increased_gObtaining a rotational speed limit value omega_g+At this time, calculateObtaining an optimum torque T_opt2。

8. The method for improving the power generation capacity of the high-altitude wind power generation set according to claim 1, wherein an objective function is constructed in the step G)WhereinFor the output power of the ith wind turbine generator,the rate of change of the bending moment in the plane,out-of-plane bending moment variation ratio, P'_maxIs the estimated value of the maximum unit power, delta M'_f,maxIs an in-plane bending moment estimate, delta M'_e,maxThe out-of-plane bending moment value is, mu is an adjusting parameter, mu is more than or equal to 0 and less than or equal to 1.

9. The method for improving the power generation capacity of the high-altitude wind power generation set according to claim 1 or 8, wherein the objective function P (ω) is subjected to particle swarm optimization in the step G)_g) Optimizing, comprising the following steps:

G1) generating initial particles and establishing a population, wherein each particle represents a rotating speed combination [ omega ] of each unit_g1,ω_g2,...,ω_gKSetting the target function as a fitness function, and setting the initial positions of particle swarm size N and w particlesPopulation position P, initial velocity of w-th particleFitness constraint condition, inertia weight omega, maximum iteration time T and individual optimal position p of w-th particle_hbestAnd the population optimal position P_gbest；

G2) Calculating a fitness function value of each particle, evaluating the fitness function value of each particle, and obtaining an evaluation result;

G3) updating the individual optimal position p according to the evaluation result_hbestAnd the population optimal position P_gbestUpdating the particle speed and the particle position;

G4) judging whether a fitness constraint condition or the maximum iteration times is reached, if so, finishing the optimization process, and obtaining an optimal solution of each set rotating speed combination which enables the wind energy capture output power of the wind turbine generator to be maximum and the load to be minimum; if not, return to G2).

10. The method for improving the power generation capacity of the high-altitude wind power generation set according to claim 9, wherein in the step G3), after the t iteration, the population position is recorded asThe particle velocity update formula is:

wherein the content of the first and second substances,representing the velocity of the d-th dimension of the w-th particle at the t-th iteration,denotes the position of the w-th particle in the d-th dimension at the t-th iteration, ω is the inertial weight, L₁、L₂As a learning factor, R₁、R₂Are independent of each other and are uniformly distributed in [0,1 ]]The random number of the interval is set to be,for the individual optimal position of the w-th particle in the d-th dimension at the t-th iteration,the optimal position of the d-dimension population in the t iteration is obtained;

the particle position update formula is:wherein the content of the first and second substances,representing the velocity of the w-th particle in the d-th iteration.

Technical Field

The invention relates to the technical field of wind power generation, in particular to a method for improving the generating capacity of a high-altitude wind turbine generator system.

Background

The blade is used as a source for wind energy absorption of the wind generating set, and how to capture more wind energy under the same impeller wind sweeping area is the most desired target for various wind generating set manufacturers. With the continuous increase of installed capacity of wind generating sets, the unit capacity and the impeller diameter of the wind generating sets are rapidly increased, and the development of wind power plants is expanding to low wind speed and plateau areas. In high altitude areas, due to the lower air density, the aerodynamic power of the impeller does not increase any more but decreases with increasing wind speed, forcing the blades into a stall condition. For the blades, the airflow adjacent to the surface of the blades is separated from the surface and generates resistance, when the attack angle is larger, the airflow is separated from the blades, the lift-drag ratio of the blades is rapidly reduced after reaching the maximum value, and the stall phenomenon influences the wind energy utilization efficiency of the wind generating set, so that the generating capacity of the wind power plant is reduced, and the economic benefit of the wind power plant is reduced.

According to the conventional method in the industry, the vortex generator is mounted on the blade of the wind turbine generator, the flow guide part is arranged on the vortex generator to play a role in rectification, the flow in the air flow direction can be reduced, and the stall state of the blade of the wind turbine generator is slowed down through the matching of the flow guide part and the vortex generation part, so that the aerodynamic performance of the blade is improved. Although the solution of installing the vortex generator can slow down the stall state of the blade to some extent, for the wind turbine blade already installed on site, the installation of the vortex generator faces the construction problem of huge engineering and high cost.

For example, a chinese patent document discloses a pitch control method and system for a wind turbine generator system, which is published under the publication number CN 109209765 a, and the invention includes: a main controller of the wind generating set predicts the variable pitch control data of each control period in advance of a preset time period; the main controller generates a corresponding prediction variable pitch control instruction according to the variable pitch control data, and sends the prediction variable pitch control instruction to the variable pitch controller so that the variable pitch controller stores the prediction variable pitch control instruction according to a receiving sequence; and if the communication of the conductive slip ring is interrupted, the variable pitch controller sequentially executes the prediction variable pitch control instructions according to the storage sequence of the prediction variable pitch control instructions so as to perform variable pitch operation. The invention can not solve the problem that the air density of the high-altitude area is low, so that the power generation amount of the wind generating set is reduced.

Disclosure of Invention

The invention aims to solve the problem that the generated energy of a wind generating set is low at the same wind speed due to low air density in a high altitude area, and provides a method for improving the generated energy of the wind generating set at the high altitude.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for improving the generating capacity of a high-altitude wind turbine generator set comprises the following steps:

A) acquiring atmospheric pressure p and extravehicular temperature t, and calculating air density rho;

B) obtaining the rotating speed omega of the generator_gAnd a wind wheel radius r, and obtaining C of the wind turbine through aerodynamic calculation_pLambda characteristic curve of_pIs the power coefficient, and λ is the tip speed ratio;

C) obtaining a theoretical wind speed upsilon based on a tip speed ratio lambda, and calculating the output power P of the wind turbine generator and the torque T of the wind turbine generator;

D) setting a wind speed regulation range, and obtaining an optimal torque T when the wind speed upsilon is within the wind speed regulation range_opt1Setting the unit torque T to the optimum torque T_opt1；

E) When the adjusting range of the rotating speed of the unit reaches the upper limit of the adjusting range of the wind speed, the optimal torque T is obtained_opt2Setting the unit torque T to the optimum torque T_opt2；

F) Setting an upper limit T of torque_maxAnd generator speed upper limit omega_{g max}Obtaining a constraint conditionT_iSet torque, ω, for the ith wind turbine_giThe number is the generator speed of the ith wind turbine generator, and K is the total number of the wind turbine generators;

G) and constructing an objective function, and optimizing the objective function by using an optimization algorithm to obtain each set rotating speed combination which enables the wind energy capture output power of the wind turbine generator to be maximum and the load to be minimum.

By obtaining the optimal torque under different conditions, the speed ratio of the blade tips of the units in the high-altitude area can also reach the actual best, the wind energy capture coefficient is maximized, the generated energy of the wind generation set is improved, and the maximum power capture and the minimum load of each unit in the wind power plant are realized by utilizing an optimization algorithm.

Further, calculating in step A)Obtaining the air density rho, wherein M is the standard air molar mass and R is a gas constant.

And acquiring signals of air pressure p and temperature t through an outdoor atmospheric pressure sensor and an outdoor temperature sensor, and then acquiring real-time air density rho according to a Clapeyron equation of Clappelon.

Further, in step C) by calculatingAnd obtaining a theoretical wind speed upsilon based on a tip speed ratio lambda, wherein G is a gearbox speed ratio.

The tip speed ratio is the ratio of the tip linear speed of the blade to the wind speed and is an important parameter representing the performance of the wind turbine, and the tip speed ratio represents the operating speed of the wind turbine unit under a certain wind speed.

Further, calculating in step C)And obtaining the output power P of the wind turbine generator, wherein A is the wind sweeping area of the impeller.

And obtaining the wind turbine power P based on the atmospheric pressure and the extravehicular temperature according to a wind turbine energy conversion formula.

Further, calculating in step C)And obtaining the torque T of the unit.

Machine set power P and generator rotation speed omega_gIs in direct proportion to the torque T, and improves the rotating speed omega of the generator_gOr the unit power P can be increased by increasing the torque T, and the torque cannot be further increased for the unit with the determined rated capacity. Therefore, if the rated power of the unit is kept unchanged, the rotating speed omega of the wind wheel is increased_gThe upper limit of the maximum power coefficient C of the unit_{p max}。

Further, in step D), when the wind speed upsilon is in the wind speed adjusting range, the optimal torque T is obtained_opt1The method comprises the following steps:

D1) for actual generator speed omega_gCompensating to obtain the actual optimal tip speed ratio lambda_optAnd the actual optimum tip speed ratio lambda_optCorresponding maximum power coefficient maximum C_{p max}；

D2) Obtaining the tip speed ratio lambda reaching the actual optimal tip speed ratio lambda_optTheoretical rotational speed of the generatorWherein, the delta omega is a rotation speed compensation difference value;

D3) obtaining cut-in wind speed upsilon_inCut into a wind speed upsilon_outAnd rated wind speed upsilon_nWhen the wind speed is in cut-in wind speed upsilon_inAnd rated wind speed upsilon_nI.e. v_in≤v≤v_nTime, calculateObtaining an optimum torque T_opt1。

Obtaining an optimal torque T in step D)_opt2The method comprises the following steps:

when the wind speed is on rated wind speed upsilon_nAnd cut-in wind velocity upsilon_outIn the meantime, the rotating speed omega of the generator is increased_gObtaining a rotational speed limit value omega_g+At this time, calculateObtaining an optimum torque T_opt2。

In high-altitude areas, due to the fact that air density rho is low, actual wind speed upsilon captured by wind turbine generator is enabled to be low_tIs smaller than the theoretical wind speed upsilon according toIt can be seen that the actual tip speed ratio λ is larger than the theoretical value, and the actual optimum tip speed ratio λ is reached_optBy increasing the generator speed omega_gAchieving a practical optimum tip speed ratio λ_optThereby maximizing the capture coefficient of wind energy, improving the generating capacity of the wind turbine generator, respectively considering different conditions, and adjusting the rotating speed omega of the generator_gTherefore, the optimal torque under different conditions is obtained, and the tip speed ratio is optimal.

Further, constructing an objective function in step G)

WhereinFor the output power of the ith wind turbine generator,the rate of change of the bending moment in the plane,out-of-plane bending moment variation ratio, P'_maxIs the estimated value of the maximum unit power, delta M'_f,maxIs an in-plane bending moment estimate, delta M'_e,maxThe out-of-plane bending moment value is, mu is an adjusting parameter, mu is more than or equal to 0 and less than or equal to 1.

The first term of the objective functionTo power advanceThe optimization is carried out in a row mode,

second itemIndicating that the load is optimized. Mu is an adjusting parameter, mu is 1 to indicate that only the output power of the wind turbine is optimized, mu is 0 to indicate that only the load of the wind turbine is optimized, and mu is an intermediate value between 0 and 1 to indicate that the output power and the load of the wind turbine are simultaneously optimized.

Further, in the step G), a particle swarm optimization algorithm is adopted to carry out on the objective function P (omega)_g) Optimizing, comprising the following steps:

G1) generating initial particles and establishing a population, wherein each particle represents a rotating speed combination [ omega ] of each unit_g1,ω_g2,...,ω_gKSetting the target function as a fitness function, and setting the initial positions of particle swarm size N and w particlesPopulation position P, initial velocity of w-th particleFitness constraint condition, inertia weight omega, maximum iteration time T and individual optimal position p of w-th particle_hbestAnd the population optimal position P_gbest；

G2) Calculating a fitness function value of each particle, evaluating the fitness function value of each particle, and obtaining an evaluation result;

G3) updating the individual optimal position p according to the evaluation result_hbestAnd the population optimal position P_gbestUpdating the particle speed and the particle position;

G4) judging whether a fitness constraint condition or the maximum iteration times is reached, if so, finishing the optimization process, and obtaining an optimal solution of each set rotating speed combination which enables the wind energy capture output power of the wind turbine generator to be maximum and the load to be minimum; if not, return to G2).

The particle swarm optimization is an intelligent optimization method, and is realized by the cooperation of individual populationsAnd sharing information to obtain an optimal solution. Step G2) and step G3) are carried out evaluation analysis on the fitness value of each particle, and the current fitness value and the individual optimal position p are compared for each particle_hbestThe corresponding fitness values are compared, and if the current fitness value is smaller, the current fitness value is used for updating the individual optimal position p_hbest(ii) a Then the current fitness value of each particle and the optimal position P of the population_gbestThe corresponding fitness values are compared, and if the current fitness value is smaller, the current particle position is used for updating the optimal position P of the population_gbest。

Further, in step G3), after the t-th iteration, the population position is recorded asThe particle velocity update formula is:

wherein the content of the first and second substances,representing the velocity of the d-th dimension of the w-th particle at the t-th iteration,denotes the position of the w-th particle in the d-th dimension at the t-th iteration, ω is the inertial weight, L₁、L₂As a learning factor, R₁、R₂Are independent of each other and are uniformly distributed in [0,1 ]]The random number of the interval is set to be,for the individual optimal position of the w-th particle in the d-th dimension at the t-th iteration,the optimal position of the d-dimension population in the t iteration is obtained;

the particle position update formula is:wherein the content of the first and second substances,representing the velocity of the w-th particle in the d-th iteration.

In each iteration, the particle passes through the individual optimal position p_hbestAnd the population optimal position P_gbestAnd updating the speed and the position of the self-body until reaching the fitness constraint condition, namely finding the optimal solution, or reaching the maximum iteration times, and finishing the optimization process. And optimizing the objective function by adopting a particle swarm algorithm to obtain the generator rotating speed combination with the maximum power capture and the minimum load of each unit in the wind power plant.

The invention has the following beneficial effects: the speed ratio of the blade tips of the wind generation sets in the high-altitude area can also reach the actual best, the wind energy capture coefficient is maximized, the generated energy of the wind generation sets is improved, the output power and the load of the wind generation sets are optimized by utilizing an optimization algorithm, and the maximum power capture and the minimum load of each set in the wind power plant are realized.

Drawings

Fig. 1 is a control block diagram of a high altitude unit according to a first embodiment of the present invention.

FIG. 2 shows a wind turbine generator C according to an embodiment of the present invention_pGraph of the λ characteristic.

Fig. 3 is a comparison graph of the dynamic power curves of the unit before and after the optimization of the control method according to the embodiment of the present invention.

Detailed Description

The invention is further described with reference to the following detailed description and accompanying drawings.