A method for evaluating power generation of offshore wind farms integrating multiple floating wind turbines

Abstract

The present invention discloses a method for evaluating power generation of an offshore wind farm integrating multi-head floating wind turbines, comprising the following steps: S1, obtaining parameters and wind resource files of each wind turbine in the offshore wind farm; S2, calculating the real-time position of each wind turbine in the offshore wind farm according to the obtained wind turbine parameters and wind resource files, and establishing a unit position database; S3, selecting wind turbines participating in power generation calculation under different working conditions from the unit position database according to wind directions under multiple different working conditions, and calculating the power generation under different working conditions; S4, superimposing the power generation of each working condition, that is, obtaining the evaluated power generation of the offshore wind farm; the present invention can solve the problem of current dual-head floating power generation evaluation, and can select units for sector control according to wind direction, providing a more sophisticated solution for planning site selection and machine position arrangement, which is not only suitable for micro-site selection in the early stage of the wind farm, but also suitable for real-time power generation evaluation during operation.

Description

Technical Field

[0001] The present invention relates to the technical field of wind farm power generation assessment, and in particular to an offshore wind farm power generation assessment method integrating multi-head floating wind turbines. Background Art

[0002] As offshore wind power moves from shallow offshore to deep sea, the foundation form has gradually evolved from gravity, multi-pod, high pile cap, single pile, to jacket foundation and floating foundation. From an economic point of view, when the water depth is greater than 60m, floating foundation is often used. The process of large-scale unit is often equipped with larger impeller diameter and higher hub height. In order to adapt to large-scale megawatt units in deep sea and low hub height, multi-head floating type with automatic yaw capability has also come into being.

[0003] Among them, the project power generation is an important factor in determining the development of offshore wind power. However, the power generation calculation is currently based on fixed machine locations, which will overestimate the wake of multi-head floating projects, resulting in reduced returns and affecting project development decisions. Therefore, in order to accelerate the progress of deep-sea parity projects, a method for accurately evaluating the power generation of offshore wind farms that integrate multi-head floating wind turbines is needed. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and propose a method for evaluating the power generation of an offshore wind farm integrating multi-head floating wind turbines, so as to solve the current technical problem of wake evaluation when a dual-head floating wind turbine rotates.

[0005] To achieve the above object, the technical solution provided by the present invention is as follows: A method for evaluating the power generation of an offshore wind farm integrating multiple floating wind turbines, comprising the following steps:

[0006] S1. Obtain the parameters and wind resource files of each wind turbine in the offshore wind farm;

[0007] S2. Calculate the real-time position of each wind turbine in the offshore wind farm based on the obtained wind turbine parameters and wind resource files, and establish a unit position database;

[0008] S3. According to wind directions under multiple different working conditions, wind turbines participating in power generation calculation under different working conditions are selected from the unit position database to calculate the power generation under different working conditions;

[0009] S4. The power generation of each operating condition is superimposed to obtain the power generation of the offshore wind farm to be evaluated.

[0010] Further, in step S1, the wind turbine includes a fixed wind turbine and a rotary wind turbine, the fixed wind turbine includes a fixed basic wind turbine and a single-head floating wind turbine, the parameters of the fixed wind turbine include the wind turbine position coordinates, the hub center height of the fixed wind turbine, the impeller diameter of the fixed wind turbine and the power curve of the fixed wind turbine; the rotary wind turbine includes a multi-head floating wind turbine, the parameters of the rotary wind turbine include the rotation center position of the unit, the position of each head relative to the rotation center point, the hub center height of the rotary wind turbine, the impeller diameter of the rotary wind turbine and the power curve of the rotary wind turbine; the wind resource file includes a statistical file of the joint distribution of wind speed and wind direction, a wind speed time series file, a wind direction time series file, a turbulence file of the joint distribution of wind speed and wind direction, and a turbulence time series file.

[0011] Further, the step S2 comprises the following steps:

[0012] S2.1. When all wind turbines in the offshore wind farm are fixed wind turbines, the total number of wind turbine databases N = 1;

[0013] When all wind turbines in the offshore wind farm include multi-head floating wind turbines, the total number of wind turbine databases N = (WD N -WD1) / res;

[0014] The calculation range of wind direction is [WD1,WD N ), 0≤WD1<WD N <360; the calculation accuracy of wind direction is res; the total number of unit databases is N;

[0015] S2.2, according to wind direction WD1, WD2, WD3, ..., WD N Calculate the real-time position of the fan a1, a2, a3, ..., a N , archive each location and form a unit location database.

[0016] Further, the step S3 comprises the following steps:

[0017] S3.1. According to the wind direction of working condition k, select the wind turbine position involved in the calculation from the unit position database;

[0018] S3.2, assign a value to the status of each wind turbine participating in the calculation, and select the units participating in the power generation calculation, where the units participating in the calculation are recorded as 1, and the units not participating in the calculation are recorded as 0;

[0019] S3.3. Select the wake model for power generation calculation, calculate the wind speed after the wake of each wind turbine, and interpolate the wind speed-power curve to obtain the power generation under working condition k. The formula is as follows:

[0020]

[0021] In the formula, v in is the power curve cut-in wind speed, v out The wind speed at which the power curve is cut out, v i is the i-th wind speed of the power curve, p i v i The corresponding power; v i+1 is the i+1th wind speed of the power curve, p i+1 v i+1 The corresponding power; v j To calculate the wind speed of working condition k, the value is v i and v i+1 Between j v j The corresponding power;

[0022] The wind farm power generation under operating condition k is summed by the following formula:

[0023]

[0024] In the formula, p k is the power generation of the wind farm under working condition k, p j is the power generation of unit j under operating condition k, and n is the number of wind turbines involved in calculating the power generation under operating condition k;

[0025] S3.4, calculate turbulence and determine the status of the fan participating in the calculation. If there is a change, re-execute step S3.1; if the fan is running, determine the status of the fan participating in the calculation of power generation based on the turbulence calculation under each working condition; if the fan is stopped, the status data of the fan participating in the calculation is directly recorded as 0.

[0026] Further, the step S4 comprises the following steps:

[0027] The power generation under each working condition is superimposed to obtain the power generation of the wind farm. The formula is as follows:

[0028]

[0029] Where P is the wind farm power generation, p k is the power generation of all wind turbines in the kth operating condition, and m is the number of operating conditions.

[0030] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0031] The present invention can solve the current problem of dual-head floating power generation assessment, and can select units for sector control according to wind direction, providing a more sophisticated solution for site planning and machine position arrangement, which is not only suitable for the early micro-site selection of wind farms, but also for real-time power generation assessment during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a flow chart of the present invention.

[0033] Figure 2 Schematic diagram of the structure and rotation center of a fixed fan.

[0034] Figure 3 Schematic diagram of the structure and rotation center of a rotary fan.

[0035] Figure 4 Schematic diagram of the non-rotating position of a multi-head floating wind turbine in traditional calculations.

[0036] Figure 5 This is a schematic diagram of a multi-head floating wind turbine rotating with the wind direction. DETAILED DESCRIPTION

[0037] The present invention will be further described below in conjunction with specific embodiments.

[0038] See also Figure 1 As shown, this embodiment provides an offshore wind farm power generation assessment method integrating multiple floating wind turbines, comprising the following steps:

[0039] S1. Collect data: obtain the parameters and wind resource files of each wind turbine in the offshore wind farm;

[0040] Wherein, the fan includes a fixed fan and a rotary fan;

[0041] See also Figure 2 As shown, the fixed wind turbine is characterized by the rotation of the wind rotor plane around a point in the plane (r≈0), the fixed wind turbine includes a fixed basic wind turbine and a single-head floating wind turbine, and the parameters of the fixed wind turbine include the wind turbine position coordinates, the hub center height of the fixed wind turbine, the impeller diameter of the fixed wind turbine and the power curve of the fixed wind turbine;

[0042] See also Figure 3 As shown, the rotary wind turbine is characterized by a multi-head floating wind turbine whose wind wheel plane can rotate around the rotation point position to a position perpendicular to the wind direction. The rotary wind turbine includes a multi-head floating wind turbine. The parameters of the rotary wind turbine include the rotation center position of the unit, the position of each head relative to the rotation center point, the hub center height of the rotary wind turbine, the impeller diameter of the rotary wind turbine and the power curve of the rotary wind turbine; in this embodiment, the parameters of the rotary wind turbine also include the rotation center O, the rotation radius R, the distance L between each wind turbine and the impeller diameter D. The parameters are not limited to this, but should at least include the hub center position of each head of the multi-head wind turbine, and the wind resource file includes a statistical file of the joint distribution of wind speed and wind direction, a wind speed time series file, a wind direction time series file, a turbulence file of the joint distribution of wind speed and wind direction, and a turbulence time series file.

[0043] S2. Establishing a unit database: Based on the obtained wind turbine parameters and wind resource files, calculate the real-time position of each wind turbine in the offshore wind farm and establish a unit position database;

[0044] See also Figure 4 As shown in the figure, when the traditional method is used for calculation, the position of the multi-head unit does not rotate, which may cause a significant increase in the wind turbine wake of the unit under a certain wind direction, such as unit B in the schematic diagram. Therefore, the real-time position of the unit needs to be adjusted according to the wind direction.

[0045] See also Figure 5 As shown, taking a double-head wind turbine as an example, in each wind direction, the wind turbine rotates around the point so that the wind wheel plane is perpendicular to the wind direction. At this time, it is necessary to calculate the projection position corresponding to each wind wheel to ensure the accuracy of the relative position of each wind direction and each machine position, so as to reduce the error of wake calculation.

[0046] In order to improve the calculation efficiency, the unit location database is established, including the following steps:

[0047] S2.1. When all wind turbines in the offshore wind farm are fixed wind turbines, the total number of wind turbine databases N = 1;

[0048] When all wind turbines in the offshore wind farm include multi-head floating wind turbines, the total number of wind turbine databases N = (WD N -WD1) / res;

[0049] The calculation range of wind direction is [WD1,WD N ), 0≤WD1<WD N <360; the calculation accuracy of wind direction is res; the total number of unit databases is N;

[0050] S2.2, according to wind direction WD1, WD2, WD3, ..., WD N Calculate the real-time position of the fan a1, a2, a3, ..., a N , archive each location and form a unit location database.

[0051] S3, operating unit selection: According to the wind directions under multiple different working conditions, wind turbines participating in power generation calculation under different working conditions are selected from the unit position database, and the power generation under different working conditions is calculated, including the following steps:

[0052] S3.1. According to the wind direction of working condition k, select the wind turbine position involved in the calculation from the unit position database;

[0053] S3.2, assign a value to the status of each wind turbine participating in the calculation, and select the units participating in the power generation calculation, where the units participating in the calculation are recorded as 1, and the units not participating in the calculation are recorded as 0;

[0054] S3.3. Select the wake model for power generation calculation, calculate the wind speed after the wake of each wind turbine, and interpolate the wind speed-power curve to obtain the power generation under working condition k. The formula is as follows:

[0055]

[0056] In the formula, v in is the power curve cut-in wind speed, v out The wind speed at which the power curve is cut out, v i is the i-th wind speed of the power curve, p i v i The corresponding power; v i+1 is the i+1th wind speed of the power curve, p i+1 v i+1 The corresponding power; v j To calculate the wind speed of working condition k, the value is v i and v i+1 Between j v j The corresponding power;

[0057] The wind farm power generation under operating condition k is summed by the following formula:

[0058]

[0059] In the formula, p k is the power generation of the wind farm under working condition k, p j is the power generation of unit j under operating condition k, and n is the number of wind turbines involved in calculating the power generation under operating condition k;

[0060] S3.4, calculate turbulence and determine the status of the fan participating in the calculation. If there is a change, re-execute step S3.1; if the fan is running, determine the status of the fan participating in the calculation of power generation based on the turbulence calculation under each working condition; if the fan is stopped, the status data of the fan participating in the calculation is directly recorded as 0.

[0061] S4. Calculate power generation: superimpose the power generation of each working condition to obtain the power generation of the offshore wind farm to be evaluated, including the following steps:

[0062] The power generation under each working condition is superimposed to obtain the power generation of the wind farm. The formula is as follows:

[0063]

[0064] Where P is the wind farm power generation, p k is the power generation of all wind turbines in the kth operating condition, and m is the number of operating conditions.

[0065] The embodiments described above are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, all changes made according to the shape and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for evaluating power generation of an offshore wind farm integrating multiple floating wind turbines, characterized in that: The following steps are involved: S1. Obtain the parameters and wind resource files of each wind turbine in the offshore wind farm; S2. Calculate the real-time position of each wind turbine in the offshore wind farm based on the obtained wind turbine parameters and wind resource files, and establish a unit position database, including the following steps: S2.

1. When all wind turbines in the offshore wind farm are fixed wind turbines, the total number of wind turbine databases N = 1; When all wind turbines in the offshore wind farm include multi-head floating wind turbines, the total number of wind turbine databases N = (WD N -WD1) / res; The calculation range of wind direction is [WD1,WD N ), 0≤WD1<WD N <360; the calculation accuracy of wind direction is res; S2.2, according to wind direction WD1, WD2, WD3, ..., WD N Calculate the real-time position of the fan a1, a2, a3, ..., a N , archive each location and form a unit location database; S3. According to the wind directions under multiple different working conditions, wind turbines participating in power generation calculation under different working conditions are selected from the unit position database, and the power generation under different working conditions is calculated, including the following steps: S3.

1. According to the wind direction of working condition k, select the wind turbine position involved in the calculation from the unit position database; S3.2, assign a value to the status of each wind turbine participating in the calculation, and select the units participating in the power generation calculation, where the units participating in the calculation are recorded as 1, and the units not participating in the calculation are recorded as 0; S3.

3. Select the wake model for power generation calculation, calculate the wind speed after the wake of each wind turbine, and interpolate the wind speed-power curve to obtain the power generation under working condition k. The formula is as follows: In the formula, v in is the power curve cut-in wind speed, v out The wind speed at which the power curve is cut out, v i is the i-th wind speed of the power curve, p i v i The corresponding power; v i+1 is the i+1th wind speed of the power curve, p i+1 v i+1 The corresponding power; v j To calculate the wind speed of working condition k, the value is v i and v i+1 Between j v j The corresponding power is the power generation of unit j under operating condition k; The wind farm power generation under operating condition k is summed by the following formula: In the formula, p k is the power generation of the wind farm under working condition k, p j is the power generation of unit j under operating condition k, and n is the number of wind turbines involved in calculating the power generation under operating condition k; S3.4, calculate turbulence and determine the status of the fan participating in the calculation. If there is a change, re-execute step S3.1; if the fan is running, determine the status of the fan participating in the calculation of power generation based on the turbulence calculation under each working condition; if the fan is stopped, the status data of the fan participating in the calculation is directly recorded as 0; S4. The power generation of each operating condition is superimposed to obtain the power generation of the offshore wind farm to be evaluated.

2. The method for evaluating power generation of an offshore wind farm integrating multiple floating wind turbines according to claim 1 is characterized in that: In step S1, the wind turbine includes a fixed wind turbine and a rotary wind turbine. The fixed wind turbine includes a fixed basic wind turbine and a single-head floating wind turbine. The parameters of the fixed wind turbine include the wind turbine position coordinates, the hub center height of the fixed wind turbine, the impeller diameter of the fixed wind turbine and the power curve of the fixed wind turbine; the rotary wind turbine includes a multi-head floating wind turbine. The parameters of the rotary wind turbine include the rotation center position of the unit, the position of each head relative to the rotation center point, the hub center height of the rotary wind turbine, the impeller diameter of the rotary wind turbine and the power curve of the rotary wind turbine; the wind resource file includes a statistical file of the joint distribution of wind speed and wind direction, a wind speed time series file, a wind direction time series file, a turbulence file of the joint distribution of wind speed and wind direction, and a turbulence time series file.

3. The method for evaluating power generation of an offshore wind farm integrating multiple floating wind turbines according to claim 1 is characterized in that: The step S4 comprises the following steps: The power generation under each working condition is superimposed to obtain the power generation of the wind farm. The formula is as follows: Where P is the wind farm power generation, p k is the power generation of all wind turbines in the kth operating condition, and m is the number of operating conditions.

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