A method for calculating characteristics of typhoon disturbed offshore wind power output

Abstract

The application discloses a kind of typhoon disturbance offshore wind power output characteristics calculation method, it is related to wind power output calculation field, and calculation method includes, CMA data table sample is obtained by analyzing and processing past CMA data;Research sample is determined in CMA data table sample using simulation circle method;The calculation data in research sample is acquired to calculate typhoon key parameter, typhoon key parameter is analyzed using mathematical statistics method and probability distribution estimation is carried out to typhoon key parameter based on maximum likelihood estimation method to obtain primary probability distribution result, and primary probability distribution result of key parameter is tested using K-S or chi-square test and is corrected to obtain secondary probability distribution result, according to secondary probability distribution result, typhoon wind field numerical simulation obtains initial wind field simulation state;Batts wind field model is used to calculate simulation wind speed in wind field simulation state and obtain complete wind field simulation state;Simulation wind speed and current wind power station information are acquired to calculate offshore wind turbine output.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wind power output calculation, in particular to a method for calculating the characteristics of offshore wind power output disturbed by typhoon. BACKGROUND

[0002] The influence of typhoon on wind power output is two-sided. On the one hand, the strong wind brought by typhoon can significantly improve the power generation of wind turbine; on the other hand, super typhoon may cause serious mechanical damage to wind power facilities. In order to maximize the gain effect of typhoon and avoid its destructive influence, wind farm needs to adopt scientific site selection strategy, advanced disaster prevention technology and careful emergency plan.

[0003] The wind speed range in which wind turbine works is generally 3 meters / second to 25 meters / second, and the full-load wind speed range is between 11 meters / second to 25 meters / second. The strong wind brought by typhoon can significantly improve the wind speed, thereby improving the power generation efficiency of wind turbine.

[0004] Weak typhoon can improve the full-load hours of wind farm and increase the power generation. For example, affected by typhoon "Sura" and "Hawaiian", the wind farm along the coast of Fujian realized 24-hour full-power operation in early September, with a single-day power generation of 384.1 million kilowatt-hours, breaking the world record.

[0005] When typhoon above tropical storm level comes, the wind turbine will stop working; if the wind turbine is designed to withstand wind above strong typhoon, the wind turbine blades or tower will be broken.

[0006] Therefore, a method for calculating the characteristics of offshore wind power output disturbed by typhoon is needed to more accurately calculate the offshore wind power output under the disturbance of typhoon. SUMMARY

[0007] To solve the above problems, the present application provides a method for calculating the characteristics of offshore wind power output disturbed by typhoon, which aims to accurately calculate the offshore wind power output under the disturbance of typhoon and maintain the safety of wind farm.

[0008] In the present application, a method for calculating the characteristics of offshore wind power output disturbed by typhoon is provided, which includes the following steps:

[0009] S1: obtaining past CMA data, analyzing and processing the past CMA data to obtain CMA data table samples;

[0010] S2: determining research samples in the CMA data table samples by using simulation circle method;

[0011] S3: obtaining calculation data in the research samples, calculating typhoon key parameters, the typhoon key parameters including typhoon occurrence frequency, typhoon moving direction and typhoon moving speed , the minimum distance of typhoon , the central pressure difference of typhoon , the maximum wind speed radius of typhoon ;

[0012] S4: adopting mathematical statistics method to analyze the key parameters of typhoon and obtaining the primary probability distribution result of the key parameters of typhoon based on the maximum likelihood estimation method, and using K-S test or chi-square test to correct the primary probability distribution result of the key parameters to obtain the secondary probability distribution result;

[0013] S5: obtaining the secondary probability distribution result in S4, and obtaining the initial wind field simulation state from the wind field numerical simulation based on the secondary probability distribution result;

[0014] S6: calculating the simulated wind speed in the wind field simulation state by using Batts wind field model and obtaining the complete wind field simulation state;

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

[0016] Preferably, the simulated circle radius in S2 is 300km.

[0017] Preferably, the calculation method of the moving direction of typhoon in S3 comprises:

[0018] The moving direction of typhoon is defined as 0° for moving to the north, 90° for moving to the east, 180° for moving to the south, and -90° for moving to the west.

[0019] Preferably, the calculation expression of the moving speed of typhoon in S3 is:

[0020] ;

[0021] wherein, is the difference between the latitudes of two observation times, is the difference between the longitudes of two observation times, is the latitude of the first observation time, is the latitude of the second observation time.

[0022] Preferably, the calculation expression of the minimum distance of typhoon in S3 is:

[0023] ;

[0024] wherein, is the difference between the latitude of the observation point and the latitude of the center of typhoon, ​​the longitude difference between the measured point and the typhoon center, the latitude of the measured point, the latitude of the typhoon center.

[0025] preferably, the typhoon center pressure difference in S3 is calculated by the expression:

[0026] .

[0027] wherein, the typhoon center pressure.

[0028] preferably, the typhoon maximum wind speed radius in S3 is calculated by the expression:

[0029] .

[0030] preferably, in S5, the secondary probability distribution result in S4 is used to obtain the wind field simulation state according to the wind field numerical simulation of the secondary probability distribution result, and the specific content of the wind field simulation state is:

[0031] According to the secondary probability distribution result, the key parameters of the typhoon conforming to the current situation are sampled to define the current typhoon situation.

[0032] According to the typhoon moving direction in the current typhoon situation, the general trend of the typhoon is determined.

[0033] According to the typhoon minimum distance in the current typhoon situation, the typhoon starting point and the typhoon landing point are determined.

[0034] The wind speed radius in the current typhoon situation is calculated, and the wind speed radius is sorted from large to small, and the first wind speed radius in the order is selected as the target radius.

[0035] The typhoon minimum distance and the target radius are compared to form an initial typhoon numerical simulation.

[0036] preferably, in S6, the Batts wind field model is used to calculate the simulation wind speed in the wind field simulation state and obtain the complete wind field simulation state, and the specific content of the complete wind field simulation state is:

[0037] The gradient wind speed and the sea surface wind speed are calculated respectively, and the sea surface wind speed includes the maximum wind speed of 10m high on the sea surface for 10 minutes and the average wind speed at a distance of rsea surface from the typhoon center 10m high.

[0038] wherein the expression for calculating the gradient wind speed is:

[0039] .

[0040] wherein, the maximum wind speed radius, and f is the Coriolis force parameter, ​​is the central air pressure difference, K is an empirical constant, and the value is 6.72, is the gradient wind speed;

[0041] The expression of the maximum wind speed of 10m high on the sea surface for 10min average is:

[0042] (wherein is the typhoon moving speed);

[0043] The average wind speed of 10m high on the sea surface is r, and the distance from the typhoon center is:

[0044] ;

[0045] wherein, .

[0046] Preferably, the expression of the calculation of the offshore wind turbine output by acquiring the simulated wind speed in S6 and the current wind power station information in S7 is:

[0047] ;

[0048] wherein, represents the output of the wind turbine; is the rated power of the wind turbine; , , respectively represent the cut-in wind speed, the cut-out wind speed and the rated wind speed of the wind turbine;

[0049] ;

[0050] ;

[0051] .

[0052] In summary, compared with the traditional calculation technology, the calculation method of the typhoon disturbance offshore wind power output characteristics of the present application adopts the Batts wind field model to perform gradient calculation on wind speeds of different heights and different ranges to obtain more accurate influence conditions, thereby predicting and protecting the safety of the wind power plant.

[0053] The technical solutions of the present application will be further described in detail below by means of the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0054] Figure 1 is the flow chart of the calculation method of the typhoon disturbance offshore wind power output characteristics of the present application;

[0055] Figure 2 is the every 3h output characteristic curve of Guangdong Province before and after the typhoon passing;

[0056] Figure 3 The Guangdong Province monthly output characteristic curve under the influence of typhoon. DETAILED DESCRIPTION

[0057] The technical solutions of the present application are further described below by means of the accompanying drawings and examples. It should be noted that the relative arrangement, numerical expression and numerical value of the components and steps set forth in these examples do not limit the scope of the present application unless otherwise specified.

[0058] The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the present application or its application or uses.

[0059] Techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail herein. However, where appropriate, techniques, methods, and devices should be considered part of the description of the present application.

[0060] In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as a limitation. Thus, other examples of the exemplary embodiments can have different values.

[0061] Unless otherwise defined, technical terms or scientific terms used in the present application should be interpreted as their usual meanings understood by those having ordinary skill in the art to which the present application pertains.

[0062] As shown in Figure 1 , the present application provides a method for calculating the output characteristics of offshore wind power disturbed by typhoon, comprising the following steps:

[0063] S1: Obtain past CMA data, and analyze and process the past CMA data to obtain a CMA data table sample; the data is derived from CMA path data provided by the China Meteorological Administration and the China Typhoon Network. The CMA path data provided by the China Meteorological Administration and the China Typhoon Network is in different proportions.

[0064] S2: Determine a research sample in the CMA data table sample by using a simulation circle method;

[0065] Preferably, in S2, the simulation circle method only considers that typhoons passing through the simulation circle will have an impact on offshore wind power stations, and the radius of the simulation circle in the research sample determined in the CMA data table sample is 300 km.

[0066] S3: Obtain calculation data in the research sample, and calculate typhoon key parameters, including typhoon occurrence frequency, typhoon moving direction, typhoon moving speed , typhoon minimum distance , typhoon central pressure difference , and typhoon maximum wind speed radius ;

[0067] Preferably, the calculation of the moving direction of the typhoon in S3 comprises:

[0068] The moving direction of the typhoon is defined as 0° for moving to the north, 90° for moving to the east, 180° for moving to the south, and -90° for moving to the west.

[0069] Preferably, the moving speed of the typhoon in S3 is generally in the range of 2 km / h to 65 km / h. The moving speed of the typhoon can be calculated according to the latitude and longitude coordinates of the typhoon center position in the typhoon data every 3 hours The calculation expression of the moving speed of the typhoon is:

[0070]

[0071] wherein, is the difference between the latitudes of the two observation times, is the difference between the longitudes of the two observation times, is the latitude of the first observation time, is the latitude of the second observation time.

[0072] Preferably, the minimum distance of the typhoon in S3 is the distance between the typhoon center point and the offshore wind power station (measured point), and the minimum distance of the typhoon is The calculation expression of the minimum distance of the typhoon is:

[0073]

[0074] wherein, is the difference between the latitudes of the two observation times, is the difference between the longitudes of the two observation times, is the latitude of the first observation time, is the latitude of the second observation time.

[0075] Preferably, the calculation expression of the pressure difference of the typhoon center in S3 is:

[0076] .

[0077] wherein, is the pressure of the typhoon center.

[0078] Preferably, the maximum wind speed radius of the typhoon in S3 is generally in the range of 8 km-100 km, and the expression of the maximum wind speed radius of the typhoon is

[0079] .

[0080] ​​S4: using mathematical statistics method to analyze the key parameters of typhoon and based on the maximum likelihood estimation method to estimate the probability distribution of the key parameters of typhoon to obtain a probability distribution result, using K-S test or chi-square test to correct the key parameters of the first probability distribution result to obtain the second probability distribution result, as shown in Table 1;

[0081] Table 1

[0082]

[0083] S5: obtaining the second probability distribution result in S4, and according to the second probability distribution result, the initial wind field simulation state is obtained by numerical simulation of the typhoon wind field;

[0084] Preferably, in S5, the second probability distribution result in S4 is obtained, and according to the second probability distribution result, the wind field simulation state is obtained by numerical simulation of the typhoon wind field.

[0085] According to the second probability distribution result, the key parameters of the typhoon conforming to the current situation are sampled, which is defined as the current typhoon condition;

[0086] According to the moving direction of the typhoon in the current typhoon condition, the general trend of the typhoon is determined;

[0087] According to the minimum distance of the typhoon in the current typhoon condition, the starting point and the landing point of the typhoon are determined;

[0088] The wind speed radius in the current typhoon condition is calculated, the wind speed radius is sorted from large to small, and the first wind speed radius in the order is selected as the target radius;

[0089] The minimum distance of the typhoon and the target radius are compared to form an initial typhoon numerical simulation.

[0090] S6: using Batts wind field model to calculate the simulated wind speed in the wind field simulation state and obtain the complete wind field simulation state;

[0091] Preferably, in S6, the specific content of using Batts wind field model to calculate the simulated wind speed in the wind field simulation state and obtain the complete wind field simulation state is:

[0092] The gradient wind speed and the sea surface wind speed are calculated respectively, and the sea surface wind speed includes the maximum wind speed of 10m high 10min average on the sea surface and the average wind speed at the distance of r sea surface 10m high from the typhoon center;

[0093] The expression for calculating the gradient wind speed is:

[0094] ;

[0095] Wherein, is the maximum wind speed radius, and f is the Coriolis force parameter, is the central pressure difference, K is an empirical constant with a value of 6.72, is the gradient wind speed, the Coriolis parameter where is the earth's angular velocity, is the latitude.

[0096] The expression for the maximum wind speed averaged over 10 min at 10 m above sea level is:

[0097] where is the typhoon translation speed;

[0098] The average wind speed at 10 m above sea level at a distance r from the typhoon center is:

[0099]

[0100] where .

[0101] Preferably, in S7, the selected offshore wind farm in Guangdong Province in S6 is taken as the measured point, the latitude and longitude coordinates of the wind farm, the wind turbine model and the number of wind turbines are queried, and the cut-in wind speed, the cut-out wind speed, the rated wind speed and the rated power are determined.

[0102] Given the wind speed of the wind turbine generator, the output power of the wind farm can be calculated according to the relationship curve between the output power of the wind turbine and the wind speed. The expression for calculating the output power of the offshore wind turbine generator based on the simulated wind speed and the current wind farm information is:

[0103]

[0104] In the formula, represents the output power of the wind turbine generator; is the rated power of the wind turbine generator; , , respectively represent the cut-in wind speed, the cut-out wind speed and the rated wind speed of the wind turbine;

[0105]

[0106]

[0107] .

[0108] S7: Calculate the output power of the offshore wind turbine generator based on the simulated wind speed and the current wind farm information in S6.

[0109] ​​​​At present, all offshore wind farms in Guangdong Province are mainly concentrated in the east and west regions of Guangdong Province. According to the above steps, the output of each region of the wind farm is solved, and the output of different wind farms at each time is accumulated in turn, so as to obtain the output of offshore wind power in Guangdong Province during the passage of typhoon, and thus the output of offshore wind power in Guangdong Province before and after the passage of typhoon is calculated as shown in Figure 2 .Each measured point in the region is calculated respectively, and the output of all measured points is accumulated to obtain the 3h output characteristic curve of Guangdong Province before and after the passage of typhoon, wherein the sampling sample typhoon path interval is 3h.

[0110] Typhoon is divided into six grades according to intensity, i.e. tropical depression, tropical storm, strong tropical storm, typhoon, strong typhoon and super typhoon, and the corresponding central pressures are 1000pha-1005pha, 980pha-1000pha, 970pha-980pha, 960pha-970pha, 940pha-960pha and ≤940pha. The typhoon intensity grades and central pressures of six sampling samples are determined , and the power generation of the measured point under this intensity grade is calculated . The power generation of the measured point under the remaining intensity grades is calculated as follows:

[0111]

[0112] , wherein, is the central pressure corresponding to different typhoon intensity grades; is the power generation of the measured point under different typhoon intensity grades; =2,3,4,5,6 ( )

[0113] The power generation of the measured point without typhoon influence for the same sampling sample duration is calculated, and the disturbance coefficient of typhoon to the measured point is defined as:

[0114]

[0115] The frequency and duration of each month of typhoon are obtained from historical data, and the power generation of the measured point of each month is calculated according to 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 .

[0116] Output=power generation / running time, so as to obtain the monthly output characteristic curve of Guangdong Province.

[0117] It should be pointed out finally that the above examples are only used to illustrate the technical solutions of the present application but not to limit it, and although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can still be modified or replaced equivalently, and these modifications or equivalent replacements should not make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. A method for calculating the output characteristics of offshore wind power under typhoon disturbance, characterized in that, Includes the following steps: S1: Obtain historical CMA data, analyze and process the historical CMA data to obtain a sample CMA data table; S2: The simulated circle method was used to determine the research sample in the CMA data table sample; S3: Obtain computational data from the research sample and calculate key typhoon parameters, including typhoon occurrence frequency, typhoon direction of movement, and typhoon speed. minimum distance of typhoon Pressure difference at the center of the typhoon , radius of maximum wind speed of typhoon ; S4: Mathematical statistics methods are used to analyze the key parameters of the typhoon and the probability distribution of the key parameters is estimated based on the maximum likelihood estimation method to obtain the first probability distribution result. The first probability distribution result of the key parameters is tested by KS or chi-square test and corrected to obtain the second probability distribution result. S5: Obtain the quadratic probability distribution result from S4. Based on the quadratic probability distribution result, perform numerical simulation of the typhoon wind field to obtain the initial wind field simulation state. S6: The Batts wind field model is used to calculate the simulated wind speed in the wind field simulation state and obtain the complete wind field simulation state; S7: Calculate the output of offshore wind turbines by obtaining the simulated wind speed and current wind power station information from S6.

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 was 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 methods for the direction of typhoon movement in S3 include: The movement direction of typhoons is defined as follows: 0° for due north, 90° for due east, 180° for due south, and -90° for due west.

4. The method for calculating the output characteristics of offshore wind power under typhoon disturbance according to claim 1, characterized in that, S3 Typhoon Movement Speed The calculation expression is: ； in, The difference between the sub-latitudes at the two observations. The difference between the second longitude at the two observation times. The latitude at the time of the first observation. This refers to the latitude at the time of the second observation.

5. The method for calculating the output characteristics of offshore wind power under typhoon disturbance according to claim 1, characterized in that, S3 minimum distance of typhoon The calculation expression is: ； in, This represents the latitude difference between the measured point and the typhoon center. This represents the difference in longitude between the measured point and the typhoon center. The latitude of the measured point. This refers to the latitude of the typhoon's center.

6. The method for calculating the output characteristics of offshore wind power under typhoon disturbance according to claim 1, characterized in that, The central pressure difference of Typhoon S3 The calculation expression is: ； in, This refers to the central pressure of the typhoon.

7. The method for calculating the output characteristics of offshore wind power under typhoon disturbance according to claim 1, characterized in that, The maximum wind speed radius of Typhoon S3 The expression is: ； in, This refers to the central pressure of the typhoon.

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 quadratic probability distribution result from S4 is obtained. Based on the quadratic probability distribution result, the numerical simulation of the typhoon wind field yields the following data: Based on the results of the quadratic probability distribution, key typhoon parameters that are consistent with the current situation are sampled and defined as the current typhoon status. Determine the typhoon's trajectory based on its current movement direction and typhoon status. The origin and landfall point of a typhoon are determined based on the minimum distance between the typhoon and the current typhoon conditions. Calculate the wind speed radius in the current typhoon conditions, sort the wind speed radii from largest to smallest, and select the wind speed radius with the largest wind speed as the target radius; The minimum distance to the typhoon is compared with the target radius to form an initial numerical simulation of the typhoon.

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 complete details of the wind field simulation state as follows: Calculate the gradient wind speed and the sea surface wind speed separately. The sea surface wind speed includes the maximum wind speed averaged over 10 minutes at a height of 10m above the sea surface and the average wind speed at a distance r from the typhoon center at a height of 10m above the sea surface. The expression for calculating gradient wind speed is: ； in, Where f is the radius of maximum wind speed, and f is the Coriolis force parameter. The central pressure difference is given by K, an empirical constant with a value of 6.

72. For gradient wind speed; The expression for the maximum average wind speed at a height of 10m above sea level over 10 minutes is: ； At a distance r from the typhoon center and 10m above sea level, the average wind speed is: ； in, .

10. The method for calculating the output characteristics of offshore wind power under typhoon disturbance according to claim 6, characterized in that, The expression for calculating the output of offshore wind turbines in S7 by obtaining the simulated wind speed from S6 and the current wind power station information is as follows: ； In the formula, Indicates the output of the wind turbine unit; This refers to the rated power of the wind turbine generator set; , , These represent the cut-in velocity, cut-out velocity, and rated velocity of the fan, respectively. ； ； 。

Images