A wind farm power prediction method and system considering wake propagation time delay

Abstract

The application discloses a wind farm power prediction method and system considering wake propagation time delay, and the method comprises the following steps: based on the wake accumulation effect, the time delay required for the wake to be transmitted from an upstream wind turbine to a downstream wind turbine is used to calculate the equivalent wind speed loss experienced by the downstream wind turbine at the current time; the time delay required for the wake to be transmitted from the upstream wind turbine to the downstream wind turbine is corrected; for the upstream wind turbine not affected by the wake, the output power is determined by the free incoming flow wind speed, and for the downstream wind turbine in the wake affected area, the output power is calculated by using the corrected incoming flow wind speed after the time delay, and the sum of the output powers of all the upstream wind turbines and downstream wind turbines is taken as the total power generation power of the wind farm; the application has the advantages that the accuracy of the wind farm power prediction under dynamic wind conditions is improved, and a more reliable model basis is provided for the collaborative optimization control of the wind farm.

Description

Technical Field

[0001] This invention relates to the field of wind power generation technology, and specifically to a wind farm power prediction method and system that takes into account wake propagation time delay. Background Technology

[0002] Power output prediction for wind farms is a crucial foundation for optimizing their operation and control, improving power generation efficiency, and enhancing grid stability. Accurate prediction relies heavily on the effective simulation of the complex aerodynamics within the wind farm. Among these, the wake effect between wind turbines is a core physical factor leading to downstream wind speed attenuation and impacting overall farm power. Therefore, selecting and developing a wake model that strikes a balance between prediction accuracy and computational efficiency is key to constructing a dynamic simulation and advanced control framework for wind farms.

[0003] In engineering applications, common wake models include the Frandsen model, the Gaussian model, and the classic Jensen model. Among them, the classic Jensen wake model, due to its simplified assumptions of linear wake expansion and uniform velocity deficit, has significant advantages such as simplicity, clear parameters, and high computational efficiency, and is widely used in wind farm layout design and power prediction. However, this model is based on the assumption of steady-state wind conditions, and its core flaw lies in treating wake disturbances as instantaneous transmission, ignoring a crucial physical fact: the wake propagates along the wind direction at a finite speed, resulting in a time lag in the disturbance experienced by downstream turbines. In the dynamic operating environment of actual wind farms, especially in scenarios with rapid wind speed fluctuations or dense turbine layouts, this simplified model, which ignores dynamic propagation characteristics, significantly reduces the prediction accuracy of downstream wind speed attenuation and overall power output. This limitation inherent in the model structure is difficult to correct through parameter calibration, thus affecting the effectiveness and reliability of power prediction, operation scheduling, and control strategies based on this model. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a wind farm power prediction method and system that takes into account the wake propagation time delay, so as to improve the accuracy of wind farm power prediction under dynamic wind conditions and provide a more reliable model basis for wind farm collaborative optimization control.

[0005] This invention solves the above-mentioned technical problems through the following technical means: a wind farm power prediction method considering wake propagation time delay, comprising the following steps:

[0006] S1. Based on the wake accumulation effect, the equivalent wind speed loss experienced by the downstream wind turbine at the current moment is calculated by using the time delay required for the wake to be transmitted from the upstream wind turbine to the downstream wind turbine. S2, Corrects the time delay required for the wake to be transmitted from the upstream fan to the downstream fan; S3. For upstream wind turbines not affected by the wake, their output power is determined by the free-flow wind speed. For downstream wind turbines in the wake-affected area, the output power is calculated using the inflow wind speed after time delay correction. The sum of the output power of all upstream and downstream wind turbines is the total power generation of the wind farm.

[0007] Further, S1 includes: For downstream wind turbines The sum of wind speed losses experienced at the current time t. That is, the formula for equivalent wind speed loss is:

[0008] in, Indicates the action on the downstream fan. The simplified notation for the overall wake physical delay; Indicates the downstream wind turbine The total number of upstream wind turbines that generate wake effects; Indicates the upstream wind turbine number. Indicates the downstream fan number; Indicates the swept area of ​​the wind turbine rotor; Indicates upstream wind turbine wake cross section and downstream wind turbine The overlapping area between the areas swept by the wind turbines; Indicates upstream wind turbine At a historical moment The thrust coefficient; Indicates the diameter of the wind turbine; Indicates the wake expansion coefficient; Indicates upstream wind turbine Downstream wind turbines Downwind distance between them; This indicates that the wake originates from the upstream wind turbine. Propagation to downstream wind turbines The required time delay.

[0009] Furthermore, the time delay required for the corrected wake to travel from the upstream turbine to the downstream turbine includes:

[0010] in, Indicates the effective inflow velocity; This represents the intermediate variable of wake intensity, determined jointly by the wake overlap area and the upstream turbine thrust coefficient. ; Indicates the upstream wind turbine at a certain time. The thrust coefficient.

[0011] Furthermore, the formula for calculating the effective inflow velocity is:

[0012] in, Representing the integral variable The free-flowing wind speed at the corresponding moment; This represents the integral variable within the wake propagation time window; Indicates the current time The free flow of wind speed; Indicates the delayed backtracking time The free flow of wind speed.

[0013] Furthermore, the formula for calculating the output power of the upstream wind turbine is as follows:

[0014] in, Indicates upstream wind turbine ; output power; Indicates air density; Indicates upstream wind turbine The free flow of wind speed at the location; Indicates upstream wind turbine The corresponding wind energy utilization coefficient.

[0015] Furthermore, the formula for calculating the output power of the downstream wind turbine is as follows:

[0016] in, Indicates downstream wind turbine ; output power; Indicates downstream wind turbine The corresponding wind energy utilization coefficient.

[0017] Furthermore, the formula for calculating the total power generation of the wind farm is as follows:

[0018] in, This indicates the total power generation capacity of the wind farm; Indicates the first The output power of the typhoon generator; This indicates the total number of upstream and downstream wind turbines within a wind farm.

[0019] The present invention also provides a wind farm power prediction system that considers wake propagation time delay, comprising: The wake accumulation module is used to calculate the equivalent wind speed loss experienced by the downstream wind turbine at the current moment based on the wake accumulation effect and the time delay required for the wake to be transmitted from the upstream wind turbine to the downstream wind turbine. The time delay correction module is used to correct the time delay required for the wake to be transmitted from the upstream wind turbine to the downstream wind turbine; The power prediction output module is used to calculate the output power of upstream wind turbines that are not affected by the wake, based on the free-flow wind speed. For downstream wind turbines in the wake-affected area, the output power is calculated using the inflow wind speed after time delay correction. The sum of the output power of all upstream and downstream wind turbines is the total power generation of the wind farm.

[0020] Furthermore, the wake accumulation module is also used for: For downstream wind turbines The sum of wind speed losses experienced at the current time t. That is, the formula for equivalent wind speed loss is:

[0021] in, Indicates the action on the downstream fan. The simplified notation for the overall wake physical delay; Indicates the downstream wind turbine The total number of upstream wind turbines that generate wake effects; Indicates the upstream wind turbine number. Indicates the downstream fan number; Indicates the swept area of ​​the wind turbine rotor; Indicates upstream wind turbine wake cross section and downstream wind turbine The overlapping area between the areas swept by the wind turbines; Indicates upstream wind turbine At a historical moment The thrust coefficient; Indicates the diameter of the wind turbine; Indicates the wake expansion coefficient; Indicates upstream wind turbine Downstream wind turbines Downwind distance between them; This indicates that the wake originates from the upstream wind turbine. Propagation to downstream wind turbines The required time delay.

[0022] Furthermore, the time delay required for the corrected wake to travel from the upstream turbine to the downstream turbine includes:

[0023] in, Indicates the effective inflow velocity; This represents the intermediate variable of wake intensity, determined jointly by the wake overlap area and the upstream turbine thrust coefficient. ; Indicates the upstream wind turbine at a certain time. The thrust coefficient.

[0024] Furthermore, the formula for calculating the effective inflow velocity is:

[0025] in, Representing the integral variable The free-flowing wind speed at the corresponding moment; This represents the integral variable within the wake propagation time window; Indicates the current time The free flow of wind speed; Indicates the delayed backtracking time The free flow of wind speed.

[0026] Furthermore, the formula for calculating the output power of the upstream wind turbine is as follows:

[0027] in, Indicates upstream wind turbine ; output power; Indicates air density; Indicates upstream wind turbine The free flow of wind speed at the location; Indicates upstream wind turbine The corresponding wind energy utilization coefficient.

[0028] Furthermore, the formula for calculating the output power of the downstream wind turbine is as follows:

[0029] in, Indicates downstream wind turbine ; output power; Indicates downstream wind turbine The corresponding wind energy utilization coefficient.

[0030] Furthermore, the formula for calculating the total power generation of the wind farm is as follows:

[0031] in, This indicates the total power generation capacity of the wind farm; Indicates the first The output power of the typhoon generator; This indicates the total number of upstream and downstream wind turbines within a wind farm.

[0032] The advantages of this invention are: (1) Based on the classic Jensen steady-state wake model, this invention introduces the wake accumulation effect, time delay mechanism and time-varying correction of incoming wind speed to construct an improved wake model to describe the dynamic wake propagation process in a wind farm. The improved wake model is used to predict the power of the wind farm. By characterizing the non-instantaneous nature of wake propagation and the time-varying nature of wind speed, the model makes the power prediction closer to the physical reality, thereby improving the accuracy of wind farm power prediction under dynamic wind conditions. This allows the power command generated by the evaluation framework to more accurately match the real-time dynamic capability of the wind farm, and ultimately improves the average output power and operational stability of the wind farm during the frequency regulation process, providing a more reliable model basis for the collaborative optimization control of the wind farm.

[0033] (2) The wake contribution of each upstream wind turbine in this invention is not calculated based on the current state. The model introduces the concept of propagation time delay. Each contribution needs to be calculated independently based on the time required for the wake to propagate from the upstream wind turbine to the target downstream wind turbine, back to the corresponding historical moment, and using the state of the upstream wind turbine at that historical moment. This state backtracking mechanism based on dedicated delay explicitly characterizes the spatiotemporal coupling effect of multi-source wakes in the dynamic propagation process in this type of engineering model. For the calculation of time delay, in order to meet the requirements of efficiency in engineering calculation while ensuring physical rationality, the model adopts a one-step iterative approximation strategy, simplifying the integral relationship to the ratio of the downwind distance between wind turbines to an equivalent propagation speed, thereby deriving an efficient and solvable analytical expression.

[0034] (3) To improve the accuracy of the model under time-varying wind conditions, this invention introduces the concept of effective inflow wind speed. This wind speed aims to correct the deviation in the calculation results caused by the variation of the free-flow wind speed itself within the propagation time window of the wake. The effective wind speed is constructed using a two-point linear interpolation method, and its value is jointly determined by the free-flow wind speed at the current time and the historical delay time. This effective wind speed is embedded into the calculation process of time delay and wake intensity. This design enables the model to reasonably reflect the influence of time-varying wind speed on the dynamic development process of the wake without excessively increasing the computational complexity, thus achieving a good balance between the physical accuracy of the model and the real-time requirements of engineering applications. Attached Figure Description

[0035] Figure 1 This is a flowchart of a wind farm power prediction method that considers wake propagation time delay, as disclosed in an embodiment of the present invention. Figure 2 This is a schematic diagram of the Jensen wake model considering the delay effect in a wind farm power prediction method that considers wake propagation time delay disclosed in an embodiment of the present invention. Figure 3This is a wind farm topology diagram in a wind farm power prediction method that considers wake propagation time delay disclosed in an embodiment of the present invention; Figure 4 This is a comparison of simulation results in a wind farm power prediction method that considers wake propagation time delay, as disclosed in an embodiment of the present invention. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Example 1 like Figure 1 As shown, Embodiment 1 of the present invention provides a wind farm power prediction method considering wake propagation time delay. Based on the classic Jensen steady-state wake model, it introduces wake accumulation effect, time delay mechanism, and time-varying correction of incoming wind speed to construct an improved wake model to describe the dynamic wake propagation process within the wind farm. This improved wake model is then used for wind farm power prediction. Specifically, it includes the following steps: S1. Dynamic loss calculation: For downstream wind turbines, the principle of linear superposition is used to calculate the equivalent wind speed loss experienced by them at the current moment. The equivalent wind speed loss is the sum of the wake loss contributions generated by all upstream wind turbines at their respective corresponding historical moments after time delay. For downstream wind turbines The sum of wind speed losses experienced at the current time t. This is equivalent to a wind speed loss, and its specific calculation expression is as follows:

[0038] in, Indicates the action on the downstream fan. The simplified notation for the overall wake physical delay; Indicates the downstream wind turbine The total number of upstream wind turbines that generate wake effects; Indicates the upstream wind turbine number. Indicates the downstream fan number; Indicates the swept area of ​​the wind turbine rotor; Indicates upstream wind turbine wake cross section and downstream wind turbine The overlapping area between the areas swept by the wind turbines; Indicates upstream wind turbine At a historical moment The thrust coefficient; Indicates the diameter of the wind turbine; Indicates the wake expansion coefficient; Indicates upstream wind turbine Downstream wind turbines Downwind distance between them; This indicates that the wake originates from the upstream wind turbine. Propagation to downstream wind turbines The required time delay depends on the downwind distance between the two turbines, the local wind speed distribution, and the historical operating status of the upstream turbine. It is for each pair of upstream wind turbines and downstream wind turbines Physical quantities that are calculated independently, while This is not a strict physical delay, but merely a variation in the formula affecting the wind turbine. The simplified notation for the combined delay effect. This expression, while retaining the Jensen model's description of wake expansion characteristics, explicitly characterizes the coupling effect of multi-source wakes through a summation form, thus more accurately reflecting the complex flow structure in dense wind farms.

[0039] When a wind turbine is simultaneously affected by multiple upstream turbines, the propagation delay times for each upstream turbine are different. In the model calculation, each wake loss contribution needs to be backtracked independently using its own dedicated delay time, i.e., using the upstream turbines... At a historical moment The state parameters are calculated to explicitly characterize the coupling effect of multi-source wakes in the dynamic process.

[0040] S2. Delay and Wind Speed ​​Correction: Based on the physical process of wake propagation, the time delay required for the wake to be transmitted from the upstream fan to the downstream fan is calculated, and an effective wind speed is constructed using a linear interpolation method to correct the influence of the time-varying nature of the incoming wind speed within the wake propagation time window on the time delay and wake intensity calculation. Defined as wake from upstream wind turbine Propagation to downstream wind turbines The required time delay, which physically depends on the local wind speed distribution along the propagation path, is defined as:

[0041] in, Represents the spatial location variable along the wake propagation path; Indicates a historical state Lower, propagation path location Local wind speed at the location; This represents the historical moment used to calculate the wake propagation state, and satisfies... Directly solving these implicit equations is computationally expensive and not suitable for real-time control applications. In most real-world wind conditions, wind speed changes relatively slowly, and a single approximation can provide sufficient accuracy.

[0042] To balance computational accuracy and efficiency, a one-step iterative approximation strategy is adopted to reduce time delay. After processing the expression, we obtain the following analytical approximation:

[0043] in, This represents the effective inflow wind speed, used to reflect the average wind speed characteristics along the wake propagation path; This represents the intermediate variable of wake intensity, determined jointly by the wake overlap area and the upstream turbine thrust coefficient. ; Indicates the upstream wind turbine at a certain time. The thrust coefficient.

[0044] Correcting the incoming wind speed within the wake propagation time window The effective inflow velocity is constructed using a two-point linear interpolation method to account for its time-varying nature; its expression is as follows:

[0045] in, Representing the integral variable The free-flowing wind speed at the corresponding moment; This represents the integral variable within the wake propagation time window; Indicates the current time The free flow of wind speed; Indicates the delayed backtracking time The free flow of wind speed.

[0046] This value retains historical information while avoiding complex numerical integration, balancing accuracy and computational efficiency, and is embedded in the calculation process of time delay and wake intensity.

[0047] S3. Power Prediction Output: For wind turbines located in the wake influence area, the aerodynamic capture power is calculated using the inflow wind speed corrected in step S2, and the power of all wind turbines is aggregated to obtain the predicted total power generation value of the wind farm.

[0048] Based on the above improvements, the calculation of the wind turbine's captured power has also been adjusted accordingly. For upstream wind turbines unaffected by the wake, their output power is still determined by the free-flow velocity:

[0049] in, Indicates upstream wind turbine ; output power; Indicates air density; Indicates upstream wind turbine The free flow of wind speed at the location; Indicates upstream wind turbine The corresponding wind energy utilization coefficient.

[0050] For downstream wind turbines located in the wake region Its output power requires the use of the inflow velocity corrected for time delay:

[0051] in, It already includes the historical wake contribution of all upstream wind turbines at their dedicated delay times.

[0052] Total power generation of wind farm The sum of the output power of all wind turbines in the field is calculated using the following formula:

[0053] in, This indicates the total power generation capacity of the wind farm; Indicates the first The output power of the typhoon generator; This indicates the total number of upstream and downstream wind turbines within a wind farm.

[0054] To verify the effectiveness of the Jensen wake model considering delay effects proposed in this invention in improving the evaluation accuracy of wind farm AGC frequency regulation support capability, this embodiment compares and analyzes the evaluation framework incorporating the improved wake model with the framework using the classic wake model, based on a typical wind farm simulation scenario. This embodiment was completed on the MATLAB / Simulink simulation platform.

[0055] like Figure 2 As shown in the figure, the core improvement of the dynamic wake modeling method proposed in this invention lies in the more physically-compliant dynamic calculation of the wind speed loss experienced by downstream wind turbines. This method first abandons the instantaneous superposition assumption in traditional models, defining the total wind speed loss experienced by the downstream wind turbine at a specific moment as the linear superposition of the wake contributions from all upstream wind turbines. (Figure...) Indicates the current Wind speed at the upstream fan location at all times. Indicates the current Wind speed at the downstream fan location at all times. express Wind speed at the upstream wind turbine before the specified time.

[0056] The key is that the wake contribution of each upstream wind turbine is not calculated based on its current state. The model introduces the concept of propagation time delay. Each contribution needs to be calculated independently by backtracking to the corresponding historical moment based on the time required for the wake to propagate from the upstream wind turbine to the target downstream wind turbine, and using the state of the upstream wind turbine at that historical moment. This state backtracking mechanism based on dedicated delay explicitly characterizes the spatiotemporal coupling effect of multi-source wakes during dynamic propagation in this type of engineering model.

[0057] Determining the time delay is a key physical foundation of the model. Essentially, it is the actual time required for the wake to propagate from the upstream wind turbine location to the downstream wind turbine location in space. This time is determined by the time-varying local wind speed distribution along the propagation path. To ensure both physical plausibility and the efficiency requirements of engineering calculations, the model employs a one-step iterative approximation strategy, simplifying the aforementioned integral relationship into the ratio of the downwind distance between wind turbines to an equivalent propagation speed, thus deriving an efficient and solvable analytical expression.

[0058] Furthermore, to improve the model's accuracy under time-varying wind conditions, this invention introduces the concept of effective inflow wind speed. This wind speed aims to correct for deviations in the calculation results caused by variations in the free-flow wind speed itself within the wake propagation time window. The effective wind speed is constructed using a two-point linear interpolation method, and its value is jointly determined by the free-flow wind speed at the current moment and at historical delay moments.

[0059] This effective wind speed is then embedded into the calculation process for time delay and wake intensity. This design allows the model to reasonably reflect the impact of wind speed time-varying characteristics on the dynamic development of the wake without excessively increasing computational complexity, thus achieving a good balance between the physical accuracy of the model and the real-time requirements of engineering applications.

[0060] To verify the effectiveness of the proposed improved wake model, it was applied to a 5x9 rectangular wind farm containing 45 NREL 5MW wind turbines, with the topology as follows: Figure 3 As shown, WT1 to W45 are the fan numbers. This represents the free-flowing wind speed. The direction of the incoming wind is perpendicular to the direction of the wind farm rows. The parameter settings for the wind farm are shown in Table 1.

[0061] Table 1 Wind Farm Parameter Settings

[0062] This invention sets up the following two comparison strategies: Strategy A (This Invention): Employs a wind farm AGC frequency regulation support capability assessment framework (i.e., the WF-MPC-SCSO method) that incorporates the "Jensen wake model considering delay effects" proposed in this invention. This framework utilizes an improved model to calculate the dynamic wake of the wind farm and predict its power, and on this basis, evaluates the available power generation (AWP) of the wind farm within each AGC control cycle.

[0063] Strategy B (Control): The evaluation framework replaces the improved wake model in Strategy A with the classic Jensen wake model (i.e., the WF-Jensen method). This model ignores the time delay of wake propagation and the time-varying nature of wind speed, and uses a steady-state formula to calculate the wake.

[0064] Both strategies operate under the same wind conditions and wind farm layout, and use the same turbine parameters, control architecture and upper-level optimization algorithm to ensure that the performance difference stems only from the difference in the wake model.

[0065] The core metric for evaluating the proposed method is the average output power (AOP), which is defined as follows:

[0066] in, Indicates average output power; Indicates the first The actual total output power of the wind farm under the corresponding strategy within each AGC control cycle; Indicates the AGC control cycle number; This represents the total number of AGC control cycles in this simulation. =200. The higher the AOP value, the higher the overall power output of the wind farm during the assessment period under this strategy. This is equivalent to the wind farm being able to more fully and stably realize its frequency regulation capability, reflecting the accuracy of the assessment framework in tapping the true dynamic potential of the wind farm.

[0067] Simulations were conducted under the aforementioned positive wind conditions, and the AOP (Aspect-Oriented Programming) of the wind farm under the two strategies were compared. Figure 4 The bar chart for the "positive blowing" operating condition is shown.

[0068] Simulation results show that the average output power obtained by using the evaluation framework (Strategy A) that incorporates the improved wake model of this invention is significantly higher than that obtained by using the framework (Strategy B) with the classic wake model. Under forward airflow conditions, the average output power is increased by approximately 7.5%.

[0069] This is clearly because, under dynamic wind conditions, the classic Jensen model, by neglecting wake propagation delay and wind speed time-varying characteristics, misjudges the extent and timing of wake effects on downstream turbines, leading to deviations in its predictions of input wind speed and AWP. This deviation propagates throughout the evaluation framework, causing the generated reference power command to be either overly conservative or overly aggressive; the latter can easily lead to power point tracking failures and instability in actual operation. The improved model proposed in this invention, by introducing a time delay mechanism and wind speed time-varying characteristic correction, more realistically simulates the physical process of wake disturbance propagation in the wind farm, thus more accurately predicting the actual available power of each turbine during dynamic processes. Based on this, the AWP evaluation is more accurate, and the generated power command can better match the real-time dynamic feasible region of the wind farm, ultimately enabling the wind farm to tap into greater power generation and frequency regulation potential while ensuring stability, resulting in a higher actual average output power (AOP).

[0070] This embodiment demonstrates through rigorous comparative simulation experiments that applying the improved Jensen wake model considering delay effects proposed in this invention to the wind farm AGC frequency regulation support capability assessment framework can significantly improve the assessment accuracy of the real-time available power boundary of the wind farm. Compared with the assessment method based on the classical steady-state wake model, this invention enables the wind farm to achieve a higher average power output under the same conditions. This is equivalent to enhancing the wind farm's ability to fulfill its frequency regulation commitment and operational stability, verifying the effectiveness and practical value of this invention in improving wind farm-level control and frequency regulation performance.

[0071] Through the above technical solutions, the improved Jensen wake model proposed in this invention, by integrating wake accumulation effect, propagation time delay and wind speed time-varying characteristics, can provide more accurate dynamic wake prediction for model predictive control (MPC) of wind farms, thereby effectively improving the power generation efficiency and operational stability of wind farms.

[0072] Example 2 Based on Embodiment 1, Embodiment 2 of the present invention further provides a wind farm power prediction system that considers wake propagation time delay, comprising: The wake accumulation module is used to calculate the equivalent wind speed loss experienced by the downstream wind turbine at the current moment based on the wake accumulation effect and the time delay required for the wake to be transmitted from the upstream wind turbine to the downstream wind turbine. The time delay correction module is used to correct the time delay required for the wake to be transmitted from the upstream wind turbine to the downstream wind turbine; The power prediction output module is used to calculate the output power of upstream wind turbines that are not affected by the wake, based on the free-flow wind speed. For downstream wind turbines in the wake-affected area, the output power is calculated using the inflow wind speed after time delay correction. The sum of the output power of all upstream and downstream wind turbines is the total power generation of the wind farm.

[0073] Specifically, the wake accumulation module is also used for: For downstream wind turbines The sum of wind speed losses experienced at the current time t. That is, the formula for equivalent wind speed loss is:

[0074] in, Indicates the action on the downstream fan. The simplified notation for the overall wake physical delay; Indicates the downstream wind turbine The total number of upstream wind turbines that generate wake effects; Indicates the upstream wind turbine number. Indicates the downstream fan number; Indicates the swept area of ​​the wind turbine rotor; Indicates upstream wind turbine wake cross section and downstream wind turbine The overlapping area between the areas swept by the wind turbines; Indicates upstream wind turbine At a historical moment The thrust coefficient; Indicates the diameter of the wind turbine; Indicates the wake expansion coefficient; Indicates upstream wind turbine Downstream wind turbines Downwind distance between them; This indicates that the wake originates from the upstream wind turbine. Propagation to downstream wind turbines The required time delay.

[0075] More specifically, the time delay required for the corrected wake to travel from the upstream turbine to the downstream turbine includes:

[0076] in, Indicates the effective inflow velocity; This represents the intermediate variable of wake intensity, determined jointly by the wake overlap area and the upstream turbine thrust coefficient. ; Indicates the upstream wind turbine at a certain time. The thrust coefficient.

[0077] More specifically, the formula for calculating the effective inflow velocity is:

[0078] in, Representing the integral variable The free-flowing wind speed at the corresponding moment; This represents the integral variable within the wake propagation time window; Indicates the current time The free flow of wind speed; Indicates the delayed backtracking time The free flow of wind speed.

[0079] More specifically, the formula for calculating the output power of the upstream wind turbine is as follows:

[0080] in, Indicates upstream wind turbine ; output power; Indicates air density; Indicates upstream wind turbine The free flow of wind speed at the location; Indicates upstream wind turbine The corresponding wind energy utilization coefficient.

[0081] More specifically, the formula for calculating the output power of the downstream wind turbine is as follows:

[0082] in, Indicates downstream wind turbine ; output power; Indicates downstream wind turbine The corresponding wind energy utilization coefficient.

[0083] More specifically, the formula for calculating the total power generation of the wind farm is as follows:

[0084] in, This indicates the total power generation capacity of the wind farm; Indicates the first The output power of the typhoon generator; This indicates the total number of upstream and downstream wind turbines within a wind farm.

[0085] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wind farm power prediction method considering wake propagation time delay, characterized in that, Includes the following steps: S1. Based on the wake accumulation effect, calculate the equivalent wind speed loss experienced by the downstream wind turbine at the current moment using the time delay required for the wake to travel from the upstream wind turbine to the downstream wind turbine; S1 includes: For downstream wind turbines The sum of wind speed losses experienced at the current time t. That is, the formula for equivalent wind speed loss is: in, Indicates the action on the downstream fan. The simplified notation for the overall wake physical delay; Indicates the downstream wind turbine The total number of upstream wind turbines that generate wake effects; Indicates the upstream wind turbine number. Indicates the downstream fan number; Indicates the swept area of ​​the wind turbine rotor; Indicates upstream wind turbine wake cross section and downstream wind turbine The overlapping area between the areas swept by the wind turbines; Indicates upstream wind turbine At a historical moment The thrust coefficient; Indicates the diameter of the wind turbine; Indicates the wake expansion coefficient; Indicates upstream wind turbine Downstream wind turbines Downwind distance between them; This indicates that the wake originates from the upstream wind turbine. Propagation to downstream wind turbines Required time delay; S2. Correction of the time delay required for the wake to travel from the upstream turbine to the downstream turbine, including: in, Indicates the effective inflow velocity; This represents the intermediate variable of wake intensity, determined jointly by the wake overlap area and the upstream turbine thrust coefficient. ; Indicates the upstream wind turbine at a certain time. The thrust coefficient; the formula for calculating the effective inflow velocity is: in, Representing the integral variable The free-flowing wind speed at the corresponding moment; This represents the integral variable within the wake propagation time window; Indicates the current time The free flow of wind speed; Indicates the delayed backtracking time The free flow of wind speed; S3. For upstream wind turbines not affected by the wake, their output power is determined by the free-flow wind speed. For downstream wind turbines in the wake-affected area, the output power is calculated using the inflow wind speed after time delay correction. The sum of the output power of all upstream and downstream wind turbines is the total power generation of the wind farm.

2. The wind farm power prediction method considering wake propagation time delay according to claim 1, characterized in that, The formula for calculating the output power of the upstream wind turbine is: in, Indicates upstream wind turbine ; output power; Indicates air density; Indicates upstream wind turbine The free flow of wind speed at the location; Indicates upstream wind turbine The corresponding wind energy utilization coefficient.

3. The wind farm power prediction method considering wake propagation time delay according to claim 2, characterized in that, The formula for calculating the output power of the downstream wind turbine is as follows: in, Indicates downstream wind turbine . output power.

4. The wind farm power prediction method considering wake propagation time delay according to claim 3, characterized in that, The formula for calculating the total power generation of the wind farm is as follows: in, This indicates the total power generation capacity of the wind farm; Indicates the first The output power of the typhoon generator; This indicates the total number of upstream and downstream wind turbines within a wind farm.

5. A wind farm power prediction system considering wake propagation time delay, comprising the method described in any one of claims 1-4, characterized in that, include: The wake accumulation module is used to calculate the equivalent wind speed loss experienced by the downstream wind turbine at the current moment based on the wake accumulation effect and the time delay required for the wake to be transmitted from the upstream wind turbine to the downstream wind turbine. The time delay correction module is used to correct the time delay required for the wake to be transmitted from the upstream wind turbine to the downstream wind turbine; The power prediction output module is used to calculate the output power of upstream wind turbines that are not affected by the wake, based on the free-flow wind speed. For downstream wind turbines in the wake-affected area, the output power is calculated using the inflow wind speed after time delay correction. The sum of the output power of all upstream and downstream wind turbines is the total power generation of the wind farm.

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