Method for calculating output characteristics of offshore wind power disturbed by typhoon

Abstract

The invention discloses a typhoon disturbance offshore wind power output characteristic calculation method, and relates to the field of wind power output calculation, and the calculation method comprises the steps: carrying out the analysis and processing of previous CMA data, and obtaining a CMA data table sample; determining a research sample in the CMA data table sample by adopting a simulated circle method; calculating typhoon key parameters by acquiring calculation data in a research sample, analyzing the typhoon key parameters by adopting a mathematical statistics method, and performing probability distribution estimation on the typhoon key parameters based on a maximum likelihood estimation method to obtain a primary approximate distribution result; k-S test or chi-square test is used for testing a primary approximate distribution result of the key parameters and correcting the primary approximate distribution result to obtain a secondary approximate distribution result, and according to the secondary approximate distribution result, numerical simulation is carried out on the typhoon wind field to obtain an initial wind field simulation state; a Batts wind field model is adopted to calculate the simulated wind speed in the wind field simulation state, and a complete wind field simulation state is obtained; and obtaining the simulated wind speed and the current wind power station information to calculate the output of the offshore wind turbine generator.

Description

Technical Field

[0001] The present invention relates to the field of wind power output calculation, and in particular to a method for calculating typhoon-disturbed offshore wind power output characteristics. Background Art

[0002] Typhoons have a two-sided impact on wind power output. On the one hand, the strong winds brought by typhoons can significantly increase the power generation of wind turbines; on the other hand, super typhoons may cause serious mechanical damage to wind power facilities. In order to maximize the benefit effect of typhoons while avoiding their destructive effects, wind farms need to adopt scientific site selection strategies, advanced disaster prevention technologies, and thorough emergency plans.

[0003] The wind speed range for wind turbines is generally 3m / s to 25m / s, and the full-power wind speed range is between 11m / s and 25m / s. The strong winds brought by typhoons can significantly increase the wind speed, thereby improving the power generation efficiency of wind turbines.

[0004] Weaker typhoons can increase the number of full-power hours of wind farms and increase power generation. For example, under the combined influence of Typhoons "Sura" and "Haikui", wind farms along the coast of Fujian achieved 24-hour full-power operation in early September, with a single-day power generation of 384,100 kWh, setting a new world record.

[0005] When a typhoon of tropical storm level or above approaches, the wind turbine will stop working; if a tropical cyclone of strong typhoon level or above is encountered, if the wind resistance design parameters of the wind turbine are exceeded, it will cause the wind turbine blades or tower to break and suffer losses.

[0006] Therefore, a method for calculating the output characteristics of offshore wind power under typhoon disturbance is urgently needed to more accurately calculate the offshore wind power output status under typhoon disturbance. Summary of the invention

[0007] To solve the above problems, the present application provides a method for calculating the output characteristics of offshore wind power under typhoon disturbance, with the goal of accurately calculating the output status of offshore wind power under typhoon disturbance, in order to maintain the safety of wind farms.

[0008] In the present application, a method for calculating the output characteristics of offshore wind power under typhoon disturbance is provided, comprising the following steps:

[0009] S1: Obtain past CMA data, analyze and process the past CMA data to obtain a CMA data table sample;

[0010] S2: The simulated circle method was used to determine the research sample in the CMA data table sample;

[0011] S3: Obtain the calculation data in the research sample and calculate the key parameters of the typhoon, which include the typhoon frequency, typhoon moving direction, typhoon moving speed VT 、Typhoon minimum distance D min , typhoon center pressure difference Δp, typhoon maximum wind speed radius R max ;

[0012] S4: Use mathematical statistics methods to analyze the key parameters of the incoming typhoon and estimate the probability distribution of the key parameters of the typhoon based on the maximum likelihood estimation method to obtain the primary distribution results. Use the KS test or chi-square test to test the primary distribution results of the key parameters and correct them to obtain the secondary distribution results;

[0013] S5: Obtain the secondary general distribution result in S4, perform numerical simulation on the typhoon wind field according to the secondary general distribution result, and obtain the initial wind field simulation state;

[0014] S6: using the Batts wind field model to calculate the simulated wind speed in the wind field simulation state and obtain the complete wind field simulation state;

[0015] S7: Obtain the simulated wind speed in S6 and the current wind power station information to calculate the output of the offshore wind turbine.

[0016] Preferably, in S2, the simulated circle method is used to determine in the CMA data table sample that the radius of the simulated circle in the research sample is 300 km.

[0017] Preferably, the calculation method of the typhoon moving direction in S2 includes:

[0018] The typhoon's movement direction is defined as 0° to the north, 90° to the east, 180° to the south, and -90° to the west.

[0019] Preferably, the typhoon moving speed V in S2 T The calculation expression is:

[0020]

[0021] Where, ΔL Lat is the difference in latitude between the two observations, ΔL Lon It is the difference in longitude between the two observations.

[0022] Preferably, the minimum typhoon distance D in S2 min The calculation expression is:

[0023]

[0024] Among them, Δφ is the latitude difference between the measured point and the typhoon center, and Δλ is the longitude difference between the measured point and the typhoon center.

[0025] Preferably, the calculation expression of the typhoon center pressure difference Δp in S2 is:

[0026] Δp=1013.3-P c .

[0027] Preferably, the maximum wind speed radius R of the typhoon in S2 max The expression is:

[0028] R max =1.119×10 3 ×(1010-P c ) -0.805 .

[0029] Preferably, in S5, the secondary general distribution result in S4 is obtained, and the content of the wind field simulation state obtained by numerically simulating the typhoon wind field according to the secondary general distribution result is as follows:

[0030] According to the results of the secondary distribution, sampling produces the key parameters of the typhoon that are in line with the current situation, which is defined as the current typhoon status;

[0031] Determine the general direction of the typhoon based on the typhoon's movement direction in the current typhoon situation;

[0032] Determine the typhoon starting point and typhoon landing point based on the minimum typhoon distance in the current typhoon conditions;

[0033] Calculate the wind speed radius in the current typhoon situation, sort the wind speed radius from large to small, and select the wind speed radius with the first order as the target radius;

[0034] The minimum typhoon distance is compared with the target radius to form an initial typhoon numerical simulation.

[0035] Preferably, in S6, the Batts wind field model is used to calculate the simulated wind speed in the wind field simulation state and obtain the specific content of the complete wind field simulation state:

[0036] The gradient wind speed and the sea surface wind speed are calculated respectively, wherein the sea surface wind speed includes the maximum wind speed averaged over 10 minutes at a height of 10 meters above the sea surface and the average wind speed at a height of 10 meters above the sea surface at a distance r from the typhoon center;

[0037] The expression for calculating the gradient wind speed is:

[0038]

[0039] Among them, R max is the maximum wind speed radius, f is the Coriolis force parameter, Δp is the central pressure difference, K is an empirical constant with a value of 6.72;

[0040] The expression of the maximum wind speed averaged over 10 minutes at a height of 10m on the sea surface is:

[0041] V 10，max =0.865Vgx +0.5V T (Where V T is the typhoon moving speed);

[0042] The average wind speed at a height of 10m above the sea surface at a distance r from the typhoon center is:

[0043]

[0044] Among them, x∈[0.5~0.7].

[0045] Preferably, the simulated wind speed in S6 and the current wind power station information are obtained in S7 to calculate the output of the offshore wind turbine as follows:

[0046]

[0047] Where p(v) represents the output of the wind turbine; P R is the rated power of the wind turbine; v ci 、v c0 、v R Respectively represent the cut-in wind speed, cut-out wind speed and rated wind speed of the fan;

[0048]

[0049] In summary, compared with traditional calculation technology, the method for calculating the output characteristics of offshore wind power under typhoon disturbance of the present invention adopts the Batts wind field model to perform gradient calculation on wind speeds at different heights and in different ranges to obtain more accurate impact conditions, thereby predicting and protecting the safety of wind farms.

[0050] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is a flow chart of a method for calculating the output characteristics of offshore wind power under typhoon disturbance according to the present invention;

[0052] Figure 2 This is the output characteristic curve every 3 hours before and after the typhoon passes through Guangdong Province;

[0053] Figure 3 This is the monthly output characteristic curve under the influence of typhoon in Guangdong Province. DETAILED DESCRIPTION

[0054] The technical solution of the present invention is further described below by means of the accompanying drawings and embodiments. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​described in these embodiments do not limit the scope of the present application.

[0055] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses.

[0056] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0057] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0058] Unless otherwise defined, technical or scientific terms used in the present invention shall have the common meanings understood by one having ordinary skills in the field to which the present invention belongs.

[0059] like Figure 1 As shown, the present invention provides a method for calculating the output characteristics of offshore wind power under typhoon disturbance, comprising the following steps:

[0060] S1: Obtain past CMA data, analyze and process past CMA data to obtain CMA data table samples; the data comes from the CMA path data provided by China Typhoon Network and China Meteorological Administration. The proportions of CMA path data provided by China Typhoon Network and China Meteorological Administration are different.

[0061] S2: The simulated circle method was used to determine the research sample in the CMA data table sample;

[0062] Preferably, the simulation circle method used in S2 only considers that typhoons passing through the simulation circle will have an impact on the offshore wind power station. In the CMA data table sample, it is determined that the radius of the simulation circle in the research sample is 300 km.

[0063] S3: Obtain the calculation data in the research sample and calculate the key parameters of the typhoon, which include the typhoon frequency, typhoon moving direction, typhoon moving speed V T 、Typhoon minimum distance D min , typhoon center pressure difference Δp, typhoon maximum wind speed radius R max ;

[0064] Preferably, the calculation method of the typhoon moving direction in S3 includes:

[0065] The typhoon's movement direction is defined as 0° to the north, 90° to the east, 180° to the south, and -90° to the west.

[0066] Preferably, the moving speed of the typhoon in S3 is generally in the range of 2km / h to 65km / h. The typhoon moving speed V can be obtained by calculating the longitude and latitude coordinates of the typhoon center position every 3 hours in the typhoon data. T The calculation expression is:

[0067]

[0068] Where, ΔL Lat is the difference in latitude between the two observations, ΔL Lon It is the difference in longitude between the two observations.

[0069] Preferably, in S3, the distance between the typhoon center and the offshore wind power station (measured point) is used as the typhoon minimum distance. The typhoon minimum distance D min The calculation expression is:

[0070]

[0071] Among them, Δφ is the latitude difference between the measured point and the typhoon center, and Δλ is the longitude difference between the measured point and the typhoon center.

[0072] Preferably, the calculation expression of the typhoon center pressure difference Δp in S3 is:

[0073] Δp=1013.3-P c .

[0074] Preferably, the maximum wind speed radius in S3 is generally within the range of 8km-100km, and the maximum wind speed radius of a typhoon is R max The expression is:

[0075] R max =1.119×10 3 ×(1010-P c ) -0.805 .

[0076] S4: Use mathematical statistics methods to analyze the key parameters of the incoming typhoon and estimate the probability distribution of the key parameters of the typhoon based on the maximum likelihood estimation method to obtain the primary distribution results. Use the KS test or chi-square test to test the primary distribution results of the key parameters and correct them to obtain the secondary distribution results, as shown in Table 1;

[0077] Table 1

[0078] Typhoon Key Parameters Probability distribution Typhoon frequency Poisson distribution Typhoon movement direction Binormal distribution Typhoon moving speed Lognormal distribution Typhoon minimum distance Even distribution Typhoon center pressure difference Lognormal distribution Typhoon maximum wind speed radius Lognormal distribution

[0079] S5: Obtain the secondary general distribution result in S4, perform numerical simulation on the typhoon wind field according to the secondary general distribution result, and obtain the initial wind field simulation state;

[0080] Preferably, in S5, the secondary general distribution result in S4 is obtained, and the content of the wind field simulation state obtained by numerically simulating the typhoon wind field according to the secondary general distribution result is as follows:

[0081] According to the results of the secondary distribution, sampling produces the key parameters of the typhoon that are in line with the current situation, which is defined as the current typhoon status;

[0082] Determine the general direction of the typhoon based on the typhoon's movement direction in the current typhoon situation;

[0083] Determine the typhoon starting point and typhoon landing point based on the minimum typhoon distance in the current typhoon conditions;

[0084] Calculate the wind speed radius in the current typhoon situation, sort the wind speed radius from large to small, and select the wind speed radius with the first order as the target radius;

[0085] The minimum typhoon distance is compared with the target radius to form an initial typhoon numerical simulation.

[0086] S6: using the Batts wind field model to calculate the simulated wind speed in the wind field simulation state and obtain the complete wind field simulation state;

[0087] Preferably, in S6, the Batts wind field model is used to calculate the simulated wind speed in the wind field simulation state and obtain the specific content of the complete wind field simulation state:

[0088] The gradient wind speed and the sea surface wind speed are calculated respectively, wherein the sea surface wind speed includes the maximum wind speed averaged over 10 minutes at a height of 10 meters above the sea surface and the average wind speed at a height of 10 meters above the sea surface at a distance r from the typhoon center;

[0089] The expression for calculating the gradient wind speed is:

[0090]

[0091] Among them, R max is the maximum wind speed radius, f is the Coriolis force parameter, Δp is the central air pressure difference, K is an empirical constant with a value of 6.72, and the Coriolis force parameter f = 2ωsinφ, where ω is the angular velocity of the earth's rotation and φ is the latitude.

[0092] The expression of the maximum wind speed averaged over 10 minutes at a height of 10m on the sea surface is:

[0093] V 10，max =0.865V gx +0.5V T (Where V T is the typhoon moving speed);

[0094] The average wind speed at a height of 10m above the sea surface at a distance r from the typhoon center is:

[0095]

[0096] Among them, x∈[0.5~0.7].

[0097] Preferably, in S7, a certain offshore wind power station in Guangdong Province is selected as the actual measurement point in S6, and the longitude and latitude coordinates, wind turbine model and number of wind turbines of the wind power station are queried to determine the cut-in wind speed, cut-out wind speed, rated wind speed and rated power.

[0098] If the wind speed of the wind turbine is known, the output power of the wind farm can be calculated based on the relationship curve between the wind turbine output power and wind speed. The output of the offshore wind turbine is calculated by simulating the wind speed and the current wind power station information as follows:

[0099]

[0100] Where p(v) represents the output of the wind turbine; P R is the rated power of the wind turbine; v ci 、v c0 、v R Respectively represent the cut-in wind speed, cut-out wind speed and rated wind speed of the fan;

[0101]

[0102] S7: Obtain the simulated wind speed in S6 and the current wind power station information to calculate the output of the offshore wind turbine.

[0103] At present, all offshore wind power stations in Guangdong Province are mainly concentrated in the eastern and western parts of Guangdong. By solving the wind power stations in each area according to the above steps and accumulating the output of different wind power stations at each moment, the output of offshore wind power in Guangdong Province before and after the typhoon is calculated. Figure 2 The output characteristic curve of Guangdong Province every 3 hours before and after the typhoon passes through is obtained by calculating each measured point in the area and accumulating the output of all measured points. The sampling interval of the typhoon path is 3 hours.

[0104] Typhoons are divided into six levels according to their intensity: tropical depression, tropical storm, severe tropical storm, typhoon, severe typhoon, and super typhoon. Assume that their central air pressures correspond to 1000pha-1005pha, 980pha-1000pha, 970pha-980pha, 960pha-970pha, 940pha-960pha, and ≤940pha. Determine the typhoon intensity level and central air pressure x1 of the six sampling samples, and calculate the power generation y1 of the measured point under this intensity level. The power generation of the measured points under other intensity levels is calculated as follows:

[0105]

[0106] Among them, x i is the central air pressure corresponding to different typhoon intensity levels; y i is the power generation of the measured point under different typhoon intensity levels; i = 2, 3, 4, 5, 6 (i ≠ 1)

[0107] Calculate the power generation of the measured point with the same sampling time without typhoon influence, and define the disturbance coefficient of typhoon on the measured point as:

[0108]

[0109] The frequency and duration of typhoons each month are obtained from historical data. The power generation of each measured point is calculated based on the frequency and duration, and the power generation of different measured points in each month is accumulated. The monthly output characteristic curve of offshore wind power in Guangdong Province is as follows: Figure 3 .

[0110] Output = power generation / operating time, and you can get the monthly output characteristic curve of Guangdong Province.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for calculating the output characteristics of offshore wind power under typhoon disturbance, characterized in that: The following steps are involved: S1: Obtain past CMA data, analyze and process the past CMA data to obtain a CMA data table sample; S2: The simulated circle method was used to determine the research sample in the CMA data table sample; S3: Obtain the calculation data in the research sample and calculate the key parameters of the typhoon, which include the typhoon frequency, typhoon moving direction, typhoon moving speed V T 、Typhoon minimum distance D min , typhoon center pressure difference Δp, typhoon maximum wind speed radius R max ; S4: Use mathematical statistics methods to analyze the key parameters of the incoming typhoon and estimate the probability distribution of the key parameters of the typhoon based on the maximum likelihood estimation method to obtain the primary distribution results. Use the KS test or chi-square test to test the primary distribution results of the key parameters and correct them to obtain the secondary distribution results; S5: Obtain the secondary general distribution result in S4, perform numerical simulation on the typhoon wind field according to the secondary general distribution result, and obtain the initial wind field simulation state; S6: using the Batts wind field model to calculate the simulated wind speed in the wind field simulation state and obtain the complete wind field simulation state; S7: Obtain the simulated wind speed in S6 and the current wind power station information to calculate the output of the offshore wind turbine.

2. The method for calculating the output characteristics of offshore wind power under typhoon disturbance according to claim 1, characterized in that: In S2, the simulated circle method is used to determine the radius of the simulated circle in the study sample to be 300 km in the CMA data table sample.

3. The method for calculating the output characteristics of offshore wind power under typhoon disturbance according to claim 1, characterized in that: The calculation method of typhoon movement direction in S2 includes: The typhoon's movement direction is defined as 0° to the north, 90° to the east, 180° to the south, and -90° to the west.

4. The method for calculating the output characteristics of offshore wind power under typhoon disturbance according to claim 1, characterized in that: S2 typhoon moving speed V T The calculation expression is: Where, ΔL Lat is the difference in latitude between the two observations, ΔL Lon It is the difference in longitude between the two observations.

5. The method for calculating the output characteristics of offshore wind power under typhoon disturbance according to claim 1, characterized in that: S2 Medium Typhoon Minimum Distance D min The calculation expression is: Among them, Δφ is the latitude difference between the measured point and the typhoon center, and Δλ is the longitude difference between the measured point and the typhoon center.

6. The method for calculating the output characteristics of offshore wind power under typhoon disturbance according to claim 1, characterized in that: The calculation expression of the typhoon center pressure difference Δp in S2 is: Δp=1013.3-P c 。 7. The method for calculating the output characteristics of offshore wind power under typhoon disturbance according to claim 1, characterized in that: S2 Medium Typhoon Maximum Wind Speed ​​Radius R max The expression is: R max =1.119×10 3 ×(1010-P c ) -0.805 。 8. The method for calculating the output characteristics of offshore wind power under typhoon disturbance according to claim 1, characterized in that: In S5, the secondary general distribution result in S4 is obtained. According to the secondary general distribution result, the typhoon wind field is numerically simulated to obtain the wind field simulation state. The content of the diagram is: According to the results of the secondary distribution, sampling produces the key parameters of the typhoon that are in line with the current situation, which is defined as the current typhoon status; Determine the direction of the typhoon based on the typhoon's movement direction in the current typhoon situation; Determine the typhoon starting point and typhoon landing point based on the minimum typhoon distance in the current typhoon conditions; Calculate the wind speed radius in the current typhoon situation, sort the wind speed radius from large to small, and select the wind speed radius with the first order as the target radius; The minimum typhoon distance is compared with the target radius to form an initial typhoon numerical simulation.

9. The method for calculating the output characteristics of offshore wind power under typhoon disturbance according to claim 1, characterized in that: In S6, the Batts wind field model is used to calculate the simulated wind speed in the wind field simulation state and obtain the specific content of the complete wind field simulation state: The gradient wind speed and the sea surface wind speed are calculated respectively, wherein the sea surface wind speed includes the maximum wind speed averaged over 10 minutes at a height of 10 meters above the sea surface and the average wind speed at a height of 10 meters above the sea surface at a distance r from the typhoon center; The expression for calculating the gradient wind speed is: Among them, R max is the maximum wind speed radius, f is the Coriolis force parameter, Δp is the central pressure difference, K is an empirical constant with a value of 6.72; The expression of the maximum wind speed averaged over 10 minutes at a height of 10m on the sea surface is: V 10，max =0.865V gx +0.5V T (Where V T is the typhoon moving speed); The average wind speed at a height of 10m above the sea surface at a distance r from the typhoon center is: Among them, x∈[0.5~0.7].

10. The method for calculating the output characteristics of offshore wind power under typhoon disturbance according to claim 6, characterized in that: In S7, the simulated wind speed in S6 and the current wind power station information are obtained to calculate the output of the offshore wind turbine as follows: Where p(v) represents the output of the wind turbine; P R is the rated power of the wind turbine; v ci 、v c0 、v R Respectively represent the cut-in wind speed, cut-out wind speed and rated wind speed of the fan;

Images