Wind turbine yaw cooperative control method and system based on yaw wake flow model

Abstract

The invention belongs to the technical field of wind turbine yaw control, and relates to a wind turbine yaw cooperative control method and system based on a yaw wake flow model. The method comprises the following steps: selecting three wind turbines as target units; calculating a power loss rate to obtain a wake flow loss evaluation index; determining the wind turbine influenced by the wake flow according to the wake flow loss evaluation index; establishing a target function taking the total output power of the wind turbines as an optimization target, establishing a function relational expression between the yaw angle and the incoming flow wind speed of the downstream fan, and determining a relational expression between the incoming flow wind speed and the output power by utilizing a static power curve of the adjacent wind turbines; and the incoming flow wind speed is set, and the yaw angle of the wind turbine under the maximum output power is determined. On the basis of a three-dimensional yaw wake flow model of the wind turbine, a target function with the total output power of the three wind turbines as an optimization target is established, an optimization strategy of the three wind turbines is obtained through yaw power calculation, and active yaw cooperative control over the wind turbine units at different wind speeds is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of wind turbine yaw control, and in particular, relates to a wind turbine yaw coordinated control method and system based on a yaw wake model. Background Art

[0002] The upstream wind speed decreases and the turbulence intensity increases after passing through the wind turbine. This phenomenon is called the wake effect. The wake effect causes the output of the downstream wind turbines within the influence range of the wind turbine wake to decrease and the fatigue load to increase. The energy loss caused has an important impact on the economic efficiency of the wind farm. The power loss of the wind turbine in the complete wake area is more significant.

[0003] At present, in the actual operation of wind farms, a single wind turbine maximizes its own power output based on the maximum power point tracking (MPPT) strategy. However, the maximum power point tracking strategy of the wind turbine itself only considers the power output of a single wind turbine, while ignoring the impact of the wake interaction between wind turbines on the power of downstream wind turbines, and thus cannot achieve the optimal output of the entire wind farm. Therefore, improving the efficiency of wind farms by alleviating the wake effect has received widespread attention.

[0004] There are two main wake control methods proposed for commercial wind farms: yaw control and axial induction factor control. The axial induction factor control method controls the thrust coefficient of the upstream unit to change its wind energy capture state, allowing more wind energy to enter the downstream, which not only increases the power generation of the downstream unit, but also reduces the adverse effects of turbulence on the service life of the downstream unit. However, this method requires precise adjustment of conditions such as the pitch angle and the unit speed according to the wind speed change, which is difficult to implement. The second method is to control the yaw of the unit. The yaw control of the unit was originally used to realize the automatic wind-facing of the impeller to achieve the maximum wind energy capture of the wind rotor. In yaw optimization control, the yaw angle is controlled to change the central area of ​​the downstream wake loss, so that it deviates from the affected wind turbine. When the working environment of the downstream wind turbine is completely in the wake area of ​​the upstream unit, the upstream wind turbine is actively yawed to control the wind rotor to a certain angle to one side, and the wake generated by the upstream wind turbine will be offset, and its wake centerline will deviate from the center of the downstream wind turbine rotor. At this time, the wake generated by the upstream wind turbine will have a reduced impact on the downstream wind turbine, thereby increasing the power of the downstream wind turbine and reducing fatigue loads. Although the upstream wind turbine will also lose power after yaw, these power losses will be compensated by the increase in power of the downstream wind turbine generator set, which is of great significance to the overall increase in power generation and efficiency of the wind power plant.

[0005] Depending on whether the control action is directly guided by the model solution, the wake control method can be divided into model-based and model-free methods. At present, the wake control method of wind farms is mainly based on the model. For the model-based method, the accuracy of the model directly affects the accuracy of the results. Therefore, the selection of the analytical model for the wake deflection of the yaw wind turbine is crucial to the solution. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a wind turbine yaw coordinated control method and system based on a yaw wake model.

[0007] In a first aspect, the present invention provides a wind turbine yaw coordinated control method based on a yaw wake model, comprising:

[0008] Three wind turbines are selected as target units. The first wind turbine, the second wind turbine and the third wind turbine are set in sequence from front to back. The first wind turbine and the second wind turbine are used as yaw control units, and the third wind turbine is used as a passive control unit. The third wind turbine is kept facing the wake of the second wind turbine. The output power of the wind turbine is the largest when it faces the incoming wind direction.

[0009] Obtain the theoretical power generation of the wind turbine and the power generation in the SCADA data of the three wind turbines, calculate the power loss rate, and obtain the wake loss evaluation index;

[0010] Determine the wind turbines affected by the wake according to the wake loss evaluation index;

[0011] Based on the three-dimensional yaw wake model of the wind turbine, an objective function with the total output power of the wind turbine as the optimization target is established, including: establishing a functional relationship expression between the yaw angle and the incoming wind speed of the downstream wind turbine based on the three-dimensional yaw wake model of the wind turbine, and determining the relationship expression between the incoming wind speed and the output power by using the difference of the static power curves of adjacent wind turbines;

[0012] The incoming wind speed is set to determine the yaw angles of the first wind turbine and the second wind turbine under maximum output power, and the yaw angle of the third wind turbine is determined according to the incoming wind speed and the yaw angle of the second wind turbine.

[0013] In a second aspect, the present invention provides a wind turbine yaw coordinated control system based on a yaw wake model, comprising a selection unit, an analysis unit, a first processing unit, an objective function establishment unit and a second processing unit;

[0014] The selection unit is used to select three wind turbines as target units, and the first wind turbine, the second wind turbine and the third wind turbine are sequentially arranged from front to back, and the first wind turbine and the second wind turbine are used as yaw control units, and the third wind turbine is used as a passive control unit; the third wind turbine is kept facing the wake of the second wind turbine; the output power of the wind turbine is maximum when it faces the incoming wind direction;

[0015] An analysis unit is used to obtain the theoretical power generation of the wind turbine and the power generation in the SCADA data of the three wind turbines, calculate the power loss rate, and obtain the wake loss evaluation index;

[0016] A first processing unit, configured to determine a wind turbine affected by a wake according to a wake loss evaluation index;

[0017] An objective function establishment unit is used to establish an objective function with the total output power of the wind turbine as the optimization target based on the three-dimensional yaw wake model of the wind turbine, including: establishing a functional relationship expression between the yaw angle and the incoming wind speed of the downstream wind turbine based on the three-dimensional yaw wake model of the wind turbine, and determining a relationship expression between the incoming wind speed and the output power by using the difference of the static power curves of adjacent wind turbines;

[0018] The second processing unit is used to set the incoming wind speed, determine the yaw angles of the first wind turbine and the second wind turbine under maximum output power, and determine the yaw angle of the third wind turbine according to the incoming wind speed and the yaw angle of the second wind turbine.

[0019] Based on the above technical solution, the present invention can also be improved as follows.

[0020] Further, a wind turbine whose hub center line is parallel to the incoming wind direction and whose distance in the wind direction is less than a set value is selected as the target unit.

[0021] Furthermore, let the power generation of the first wind turbine be HR 100 , the second wind turbine generates HR 99 , the power generation of the third wind turbine is HR 98 , the wake loss of the first wind turbine is ΔP1, and the wake loss of the second wind turbine is ΔP2, then:

[0022]

[0023] Furthermore, let x be the position coordinate of the wake region in the flow direction, y be the position coordinate of the wake region in the horizontal direction, z be the position coordinate of the wake region in the vertical direction, and u(x, y, z) be the incoming flow velocity; u hub is the incoming wind speed at the hub height, C is a parameter in the model; hub is the wheel hub height; and is the double Gaussian factor of the yaw wind turbine in the Y direction; in the double Gaussian factor, let z min is the vertical distance from the Gaussian minimum to the rotor center, σ y is the standard deviation in the horizontal direction, σ z is the standard deviation in the vertical direction, u hub is the incoming wind speed at the hub center height, and the wake radius in the vertical direction is r z , k y is the wake expansion coefficient in the horizontal direction, k z is the wake expansion coefficient in the vertical direction, r0 is the initial wake radius, y min is the horizontal distance from the Gaussian minimum to the rotor center, D is the wind turbine diameter, a is the axial induction factor; CT is the thrust coefficient of the wind turbine, u1 is the hub center speed of the first wind turbine, u2 is the hub center speed of the second wind turbine, and u3 is the hub center speed of the third wind turbine. The three-dimensional yaw wake model of the wind turbine is:

[0024]

[0025]

[0026] Furthermore, when the relationship between the incoming wind speed and the output power is determined by using the difference in the static power curves of adjacent wind turbines, when the wind turbine rotor surface is not facing the wind, the equivalent wind speed is calculated using the angle between the incoming wind speed and the vertical line of the wind rotor surface, and the wind turbine power is calculated by corresponding the equivalent wind speed to the static power curve; assuming that the incoming wind speed is v, the angle between the incoming wind speed and the vertical line of the wind rotor surface is θ, and the equivalent wind speed is v′, then:

[0027] v′=vcosθ.

[0028] Furthermore, the static power discrete points of the wind turbine are given, and the power at the ungiven wind speed points is estimated by interpolation method to obtain the static power curve of the wind turbine. The thrust coefficient of the wind turbine changes with the wind speed, and the discrete thrust curve points are fitted to obtain a segmented thrust curve as a wind speed function.

[0029] Furthermore, the yaw angles of the second wind turbine and the third wind turbine are iterated to obtain the incoming flow velocity corresponding to the optimal yaw angle; let u2 be the hub center speed of the second wind turbine, u3 be the hub center speed of the third wind turbine, u2max be the maximum value of the hub center speed of the second wind turbine, and u3max be the maximum value of the hub center speed of the third wind turbine, then:

[0030] u2max=max[cosθ2u2];

[0031] u3max=max[cosθ3u3].

[0032] Further, according to the power curve corresponding to the wind turbine, the future wind speed is substituted into the power curve to obtain the wind turbine power; let the wind turbine power of the i-th wind turbine be P i , the hub center speed of the i-th fan is u i , the relationship between the incoming wind speed and the output power is f(), then:

[0033] P i =f(u i ).

[0034] The beneficial effects of the present invention are as follows: based on the three-dimensional yaw wake model of the wind turbine, the present invention establishes an objective function with the total output power of three units as the optimization target, obtains the optimization strategy of the three wind turbines through yaw power calculation, and realizes the active yaw coordinated control of the wind turbine units under different wind speeds; at the same time, considering the influence of the yaw power of the wind turbine on the total output power and the safety of the wind turbine, a yaw condition is proposed, that is, the first wind turbine and the second wind turbine yaw and the third wind turbine does not yaw in the incoming wind direction, so as to ensure the maximum output power of the wind turbine and the service life of the deflection mechanism of the wind turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic diagram of a wind turbine yaw coordinated control method based on a yaw wake model provided in Example 1 of the present invention;

[0036] Figure 2 It is the static power curve diagram and thrust curve fitting diagram of the fan;

[0037] Figure 3 This is the relationship between the yaw angle and the total output power corresponding to the incoming wind speed;

[0038] Figure 4 Schematic diagram of a wind turbine yaw coordinated control device based on a yaw wake model provided in Example 2 of the present invention. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0040] Example 1

[0041] As an example, Figure 1 As shown, in order to solve the above technical problems, this embodiment provides a wind turbine yaw coordinated control method based on a yaw wake model, including:

[0042] Three wind turbines are selected as target units. The first wind turbine, the second wind turbine and the third wind turbine are set in sequence from front to back. The first wind turbine and the second wind turbine are used as yaw control units, and the third wind turbine is used as a passive control unit. The third wind turbine is kept facing the wake of the second wind turbine. The output power of the wind turbine is the largest when it faces the incoming wind direction.

[0043] Obtain the theoretical power generation of the wind turbine and the power generation in the SCADA data of the three wind turbines, calculate the power loss rate, and obtain the wake loss evaluation index;

[0044] Determine the wind turbines affected by the wake according to the wake loss evaluation index;

[0045] Based on the three-dimensional yaw wake model of the wind turbine, an objective function with the total output power of the wind turbine as the optimization target is established, including: establishing a functional relationship expression between the yaw angle and the incoming wind speed of the downstream wind turbine based on the three-dimensional yaw wake model of the wind turbine, and determining the relationship expression between the incoming wind speed and the output power by using the difference of the static power curves of adjacent wind turbines;

[0046] The incoming wind speed is set to determine the yaw angles of the first wind turbine and the second wind turbine under maximum output power, and the yaw angle of the third wind turbine is determined according to the incoming wind speed and the yaw angle of the second wind turbine.

[0047] Optionally, a wind turbine whose center line of the fan hub is parallel to the incoming wind direction and whose distance downwind is less than a set value is selected as the target unit.

[0048] In actual application, facing the incoming wind direction can maximize the output power of the wind turbine itself. Since there is no wind turbine downstream of the third wind turbine, the third wind turbine does not need to actively control the yaw, and can use passive yaw to always face the incoming wind direction.

[0049] The wake effect refers to the impact of the upstream wind turbine's wake on the downstream wind turbine when it passes through it. The magnitude of the impact depends on the coverage of the upstream wake on the downstream wind turbine and the distance between the two wind turbines. In order to prove the existence of wake loss and calculate the magnitude of wake loss, select the wind turbine hub center line parallel to the incoming wind direction and the unit with a close distance in the wind direction. Generally, it is not affected by the wake effect outside 8D (619.36m) of the incoming wind direction.

[0050] Wind turbine yaw coordinated control is achieved through the yaw angle of the wind turbine, and the goal is to maximize the overall output power of the unit. Therefore, the dependent variable of the objective function is the output power of the unit, and the decision variable is the yaw angle of the first and second wind turbines (the third wind turbine is designed using a passive yaw control method, and the wind wheel surface is always facing the incoming wind direction). Suppose the output power of the first wind turbine is P1, the output power of the first wind turbine is P2, the output power of the first wind turbine is P3, and the output power of all wind turbines is P, then:

[0051] P=P1+P2+P3.

[0052] Optionally, let the power generation of the first wind turbine be HR 100 , the second wind turbine generates HR 99 , the power generation of the third wind turbine is HR 98 , the wake loss of the first wind turbine is ΔP1, and the wake loss of the second wind turbine is ΔP2, then:

[0053]

[0054] Optionally, let x be the position coordinate of the wake region in the flow direction, y be the position coordinate of the wake region in the horizontal direction, z be the position coordinate of the wake region in the vertical direction, and u(x, y, z) be the incoming flow velocity; u hub is the incoming wind speed at the hub height, C is a parameter in the model; hub is the wheel hub height; and is the double Gaussian factor of the yaw wind turbine in the Y direction; in the double Gaussian factor, let z min is the vertical distance from the Gaussian minimum to the rotor center, σ y is the standard deviation in the horizontal direction, σ z is the standard deviation in the vertical direction, u hub is the incoming wind speed at the hub center height, and the wake radius in the vertical direction is r z , k y is the wake expansion coefficient in the horizontal direction, k z is the wake expansion coefficient in the vertical direction, r0 is the initial wake radius, y min is the horizontal distance from the Gaussian minimum to the rotor center, D is the wind turbine diameter, a is the axial induction factor; CT is the thrust coefficient of the wind turbine, u1 is the hub center speed of the first wind turbine, u2 is the hub center speed of the second wind turbine, and u3 is the hub center speed of the third wind turbine. The three-dimensional yaw wake model of the wind turbine is:

[0055]

[0056] Optionally, when the relationship expression between the incoming wind speed and the output power is determined by using the difference in static power curves of adjacent wind turbines, when the wind rotor surface of the wind turbine is not facing the wind, the equivalent wind speed is calculated using the angle between the incoming wind speed and the vertical line of the wind rotor surface, and the wind turbine power is calculated by corresponding the equivalent wind speed to the static power curve; assuming that the incoming wind speed is v, the angle between the incoming wind speed and the vertical line of the wind rotor surface is θ, and the equivalent wind speed is v′, then:

[0057] v′=vcosθ.

[0058] Optionally, given the static power discrete points of the wind turbine, the power at the ungiven wind speed points is estimated by interpolation to obtain the static power curve of the wind turbine. The thrust coefficient of the wind turbine changes with the wind speed, and the discrete thrust curve points are fitted to obtain a segmented thrust curve as a wind speed function.

[0059] As attached Figure 2 As shown in (a), the static power curve of the wind turbine has the horizontal axis representing wind speed in m / s and the vertical axis representing power in kW. Figure 2 (b) shows the thrust curve fitting diagram, where the horizontal axis is speed, unit: m / s, and the vertical axis is thrust coefficient CT.

[0060] Optionally, the yaw angles of the second wind turbine and the third wind turbine are iterated to obtain the incoming flow velocity corresponding to the optimal yaw angle; let u2 be the hub center speed of the second wind turbine, u3 be the hub center speed of the third wind turbine, u2max be the maximum value of the hub center speed of the second wind turbine, and u3max be the maximum value of the hub center speed of the third wind turbine, then:

[0061] u2max=max[cosθ2u2];

[0062] u3max=max[cosθ3u3].

[0063] Optionally, according to the power curve corresponding to the wind turbine, the future wind speed is substituted into the power curve to obtain the wind turbine power; let the wind turbine power of the i-th wind turbine be P i , the hub center speed of the i-th fan is u i , the relationship between the incoming wind speed and the output power is f(), then:

[0064] P i =f(u i ).

[0065] The objective function is solved, and the boundary condition is set to the yaw angle range of the first and second wind turbines to be 0° to 20°. The results of the partial inflow wind speed are shown in the attached figure. Figure 3 (a) is the relationship between the yaw angle and the total output power at 6m / s. Figure 3 (b) is the relationship between the yaw angle and the total output power at 8m / s. Figure 3 (c) is the relationship between the yaw angle and the total output power at 10m / s. Figure 3 (d) is the relationship between the yaw angle and the total output power at 12m / s. Figure 3 (e) is the relationship between the yaw angle and the total output power at 14m / s. From the figure, it can be clearly seen that the control results for achieving the maximum power generation under different incoming wind speeds.

[0066] From the results under the incoming wind speed of 6m / s, we can see that Figure 3 There is an obvious fault phenomenon in (a). When the inflow wind speed of the first fan is 6m / s, through the deflection control of the first two fans, the inflow wind speed of the third fan reaches the cut-in wind speed in some cases, but not in other cases, resulting in a fault phenomenon in the output power result diagram. From the results at inflow wind speeds of 8m / s, 10m / s and 12m / s, it can be seen that the power of the three fans changes with the deflection angles of the first and second fans. From the results at an inflow wind speed of 14m / s, it can be seen that the power of the three fans does not change with the deflection angles of the first and second fans. At this time, no matter how the deflection angle changes, the inflow wind speed of the third fan makes the fan reach the rated power. At this time, the power of the three fans remains the sum of the rated powers of the three fans.

[0067] The maximum power and corresponding yaw angle at different wind speeds are shown in Table 1.

[0068] Table 1 Maximum power and corresponding yaw angle at different wind speeds

[0069]

[0070] The present invention calculates the changes in wind speed at different yaw angles of three wind turbines, compares them with the static power curves of the wind turbines, calculates the optimal total output power and power generation of the three wind turbines, and compares them with the power generation in the SCADA data to verify the effect of yaw control on the improvement of output power.

[0071] The theoretical value of annual power generation is calculated by selecting the number of different wind speed sections of HR100 wind turbines in 2022, such as 3-4m / s, 4-5m / s, 5-6m / s, etc., corresponding to its static power curve. The theoretical value of annual power generation is 3057871kw·h, but its actual value is 3376590kw·h, with an error of 9.43%. In order to eliminate the deviation between theoretical power generation and SCADA data power generation, this paper introduces a proportional coefficient Z to correct the subsequent verification process. The expression of the proportional coefficient is as follows:

[0072]

[0073] Select a day with the most obvious wake loss phenomenon in SCADA data in the prevailing wind direction as shown in the attached figure. Figure 2 On the 6th to 12th day of (b), verification was carried out: by screening the data, the number of each wind speed interval of the first wind turbine was found, such as 3-4m / s, 4-5m / s, etc. The maximum total power generation under yaw control was obtained by the static power curve power corresponding to the number of wind speed intervals, which was 57925.61kw·h. The actual total power generation of the three wind turbines was 53472.72kw·h. It was calculated that the power increased by 7.69%, indicating that the control method has a significant effect on the power generation.

[0074] The present invention is based on a three-dimensional yaw wake model of a wind turbine, establishes an objective function with the total output power of three units as the optimization target, obtains an optimization strategy for the three wind turbines through yaw power calculation, and realizes active yaw coordinated control of wind turbine units under different wind speeds; at the same time, considering the influence of the yaw power of the wind turbine on the total output power and the safety of the wind turbine, a yaw condition for the wind turbine is proposed, that is, the first wind turbine and the second wind turbine yaw, and the third wind turbine does not yaw in the direction of the incoming wind, so as to ensure the maximum output power of the wind turbine and the service life of the deflection mechanism of the wind turbine.

[0075] Example 2

[0076] Based on the same principle as the method shown in Example 1 of the present invention, as shown in the attached Figure 4 As shown, an embodiment of the present invention also provides a wind turbine yaw coordinated control system based on a yaw wake model, including a selection unit, an analysis unit, a first processing unit, an objective function establishment unit and a second processing unit;

[0077] The selection unit is used to select three wind turbines as target units, and the first wind turbine, the second wind turbine and the third wind turbine are sequentially arranged from front to back, and the first wind turbine and the second wind turbine are used as yaw control units, and the third wind turbine is used as a passive control unit; the third wind turbine is kept facing the wake of the second wind turbine; the output power of the wind turbine is maximum when it faces the incoming wind direction;

[0078] An analysis unit is used to obtain the theoretical power generation of the wind turbine and the power generation in the SCADA data of the three wind turbines, calculate the power loss rate, and obtain the wake loss evaluation index;

[0079] A first processing unit, configured to determine a wind turbine affected by a wake according to a wake loss evaluation index;

[0080] An objective function establishment unit is used to establish an objective function with the total output power of the wind turbine as the optimization target based on the three-dimensional yaw wake model of the wind turbine, including: establishing a functional relationship expression between the yaw angle and the incoming wind speed of the downstream wind turbine based on the three-dimensional yaw wake model of the wind turbine, and determining a relationship expression between the incoming wind speed and the output power by using the difference of the static power curves of adjacent wind turbines;

[0081] The second processing unit is used to set the incoming wind speed, determine the yaw angles of the first wind turbine and the second wind turbine under maximum output power, and determine the yaw angle of the third wind turbine according to the incoming wind speed and the yaw angle of the second wind turbine.

[0082] Optionally, a wind turbine whose center line of the fan hub is parallel to the incoming wind direction and whose distance downwind is less than a set value is selected as the target unit.

[0083] Optionally, let the power generation of the first wind turbine be HR 100 , the second wind turbine generates HR 99 , the power generation of the third wind turbine is HR 98 , the wake loss of the first wind turbine is ΔP1, and the wake loss of the second wind turbine is ΔP2, then:

[0084]

[0085] Optionally, let x be the position coordinate of the wake region in the flow direction, y be the position coordinate of the wake region in the horizontal direction, z be the position coordinate of the wake region in the vertical direction, and u(x, y, z) be the incoming flow velocity; u hub is the incoming wind speed at the hub height, C is a parameter in the model; hub is the wheel hub height; and is the double Gaussian factor of the yaw wind turbine in the Y direction; in the double Gaussian factor, let z min is the vertical distance from the Gaussian minimum to the rotor center, σ y is the standard deviation in the horizontal direction, σ z is the standard deviation in the vertical direction, u hub is the incoming wind speed at the hub center height, and the wake radius in the vertical direction is r z , k y is the wake expansion coefficient in the horizontal direction, k z is the wake expansion coefficient in the vertical direction, r0 is the initial wake radius, y min is the horizontal distance from the Gaussian minimum to the rotor center, D is the wind turbine diameter, a is the axial induction factor; CT is the thrust coefficient of the wind turbine, u1 is the hub center speed of the first wind turbine, u2 is the hub center speed of the second wind turbine, and u3 is the hub center speed of the third wind turbine. The three-dimensional yaw wake model of the wind turbine is:

[0086]

[0087]

[0088] Optionally, when the relationship expression between the incoming wind speed and the output power is determined by using the difference in static power curves of adjacent wind turbines, when the wind rotor surface of the wind turbine is not facing the wind, the equivalent wind speed is calculated using the angle between the incoming wind speed and the vertical line of the wind rotor surface, and the wind turbine power is calculated by corresponding the equivalent wind speed to the static power curve; assuming that the incoming wind speed is v, the angle between the incoming wind speed and the vertical line of the wind rotor surface is θ, and the equivalent wind speed is v′, then:

[0089] v′=vcosθ.

[0090] Optionally, given the static power discrete points of the wind turbine, the power at the ungiven wind speed points is estimated by interpolation to obtain the static power curve of the wind turbine. The thrust coefficient of the wind turbine changes with the wind speed, and the discrete thrust curve points are fitted to obtain a segmented thrust curve as a wind speed function.

[0091] Optionally, the yaw angles of the second wind turbine and the third wind turbine are iterated to obtain the incoming flow velocity corresponding to the optimal yaw angle; let u2 be the hub center speed of the second wind turbine, u3 be the hub center speed of the third wind turbine, u2max be the maximum value of the hub center speed of the second wind turbine, and u3max be the maximum value of the hub center speed of the third wind turbine, then:

[0092] u2max=max[cosθ2u2];

[0093] u3max=max[cosθ3u3].

[0094] Optionally, according to the power curve corresponding to the wind turbine, the future wind speed is substituted into the power curve to obtain the wind turbine power; let the wind turbine power of the i-th wind turbine be P i , the hub center speed of the i-th fan is u i , the relationship between the incoming wind speed and the output power is f(), then:

[0095] P i =f(u i ).

[0096] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A wind turbine yaw coordinated control method based on a yaw wake model, characterized in that: include: Three wind turbines are selected as target units. The first wind turbine, the second wind turbine and the third wind turbine are set in sequence from front to back. The first wind turbine and the second wind turbine are used as yaw control units, and the third wind turbine is used as a passive control unit. The third wind turbine is kept facing the wake of the second wind turbine. The output power of the wind turbine is the largest when it faces the incoming wind direction. Obtain the theoretical power generation of the wind turbine and the power generation in the SCADA data of the three wind turbines, calculate the power loss rate, and obtain the wake loss evaluation index; Determine the wind turbines affected by the wake according to the wake loss evaluation index; Based on the three-dimensional yaw wake model of the wind turbine, an objective function with the total output power of the wind turbine as the optimization target is established, including: establishing a functional relationship expression between the yaw angle and the incoming wind speed of the downstream wind turbine based on the three-dimensional yaw wake model of the wind turbine, and determining the relationship expression between the incoming wind speed and the output power by using the static power curve of the adjacent wind turbine; The incoming wind speed is set to determine the yaw angles of the first wind turbine and the second wind turbine under maximum output power, and the yaw angle of the third wind turbine is determined according to the incoming wind speed and the yaw angle of the second wind turbine.

2. The wind turbine yaw coordinated control method based on the yaw wake model according to claim 1 is characterized in that: The wind turbines whose hub center line is parallel to the incoming wind direction and whose distance to the wind direction is less than the set value are selected as the target units.

3. The wind turbine yaw coordinated control method based on the yaw wake model according to claim 1 is characterized in that: Assume that the power generation of the first wind turbine is HR 100 , the second wind turbine generates HR 99 , the power generation of the third wind turbine is HR 98 , the wake loss of the first wind turbine is ΔP1, and the wake loss of the second wind turbine is ΔP2, then:

4. The wind turbine yaw coordinated control method based on the yaw wake model according to claim 1 is characterized in that: Let x be the position coordinate of the wake area in the flow direction, y be the position coordinate of the wake area in the horizontal direction, z be the position coordinate of the wake area in the vertical direction, and u(x,y,z) be the incoming flow velocity; hub is the incoming wind speed at the hub height, C is a parameter in the model; hub is the wheel hub height; and is the double Gaussian factor of the yaw wind turbine in the Y direction; in the double Gaussian factor, let z min is the vertical distance from the Gaussian minimum to the rotor center, σ y is the standard deviation in the horizontal direction, σ z is the standard deviation in the vertical direction, u hub is the incoming wind speed at the hub center height, and the wake radius in the vertical direction is r z , k y is the wake expansion coefficient in the horizontal direction, k z is the wake expansion coefficient in the vertical direction, r0 is the initial wake radius, y min is the horizontal distance from the Gaussian minimum to the rotor center, D is the wind turbine diameter, a is the axial induction factor; CT is the thrust coefficient of the wind turbine, u1 is the hub center speed of the first wind turbine, u2 is the hub center speed of the second wind turbine, and u3 is the hub center speed of the third wind turbine. The three-dimensional yaw wake model of the wind turbine is:

5. The wind turbine yaw coordinated control method based on the yaw wake model according to claim 1, characterized in that: When the static power curve of the adjacent wind turbine is used to determine the relationship between the incoming wind speed and the output power, when the wind turbine rotor surface is not facing the wind, the equivalent wind speed is calculated using the angle between the incoming wind speed and the vertical line of the wind rotor surface, and the wind turbine power is calculated by corresponding the equivalent wind speed to the static power curve; assuming that the incoming wind speed is v, the angle between the incoming wind speed and the vertical line of the wind rotor surface is θ, and the equivalent wind speed is v′, then: v′=vcosθ.

6. The wind turbine yaw coordinated control method based on the yaw wake model according to claim 1, characterized in that: The static power discrete points of the wind turbine are given. For the power at the ungiven wind speed points, the interpolation method is used to estimate and obtain the static power curve of the wind turbine. The thrust coefficient of the wind turbine changes with the wind speed. The discrete thrust curve points are fitted to obtain a segmented thrust curve as a wind speed function.

7. The wind turbine yaw coordinated control method based on the yaw wake model according to claim 1 is characterized in that: Iterate the yaw angles of the second and third wind turbines to obtain the incoming flow velocity corresponding to the optimal yaw angle; let u2 be the hub center speed of the second wind turbine, u3 be the hub center speed of the third wind turbine, u2max be the maximum value of the hub center speed of the second wind turbine, and u3max be the maximum value of the hub center speed of the third wind turbine, then: u2max=max[cosθ2u2]; u3max=max[cosθ3u3].

8. The wind turbine yaw coordinated control method based on the yaw wake model according to claim 7 is characterized in that: According to the power curve corresponding to the wind turbine, substitute the future wind speed into the power curve to obtain the wind turbine power; let the wind turbine power of the i-th wind turbine be P i , the hub center speed of the i-th fan is u i , the relationship between the incoming wind speed and the output power is f(), then: P i =f(u i )。 9. A wind turbine yaw coordinated control system based on a yaw wake model, characterized in that: It includes a selection unit, an analysis unit, a first processing unit, an objective function establishment unit and a second processing unit; The selection unit is used to select three wind turbines as target units, and the first wind turbine, the second wind turbine and the third wind turbine are sequentially arranged from front to back, and the first wind turbine and the second wind turbine are used as yaw control units, and the third wind turbine is used as a passive control unit; the third wind turbine is kept facing the wake of the second wind turbine; the output power of the wind turbine is maximum when it faces the incoming wind direction; An analysis unit is used to obtain the theoretical power generation of the wind turbine and the power generation in the SCADA data of the three wind turbines, calculate the power loss rate, and obtain the wake loss evaluation index; A first processing unit, configured to determine a wind turbine affected by a wake according to a wake loss evaluation index; An objective function establishment unit is used to establish an objective function with the total output power of the wind turbine as the optimization target based on the three-dimensional yaw wake model of the wind turbine, including: establishing a functional relationship expression between the yaw angle and the incoming wind speed of the downstream wind turbine based on the three-dimensional yaw wake model of the wind turbine, and determining a relationship expression between the incoming wind speed and the output power by using the difference of the static power curves of adjacent wind turbines; The second processing unit is used to set the incoming wind speed, determine the yaw angles of the first wind turbine and the second wind turbine under maximum output power, and determine the yaw angle of the third wind turbine according to the incoming wind speed and the yaw angle of the second wind turbine.

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