CN114398842A - A method for evaluating the power generation of a running wind farm - Google Patents

Abstract

The invention discloses a method for evaluating the power generation of a wind farm in operation. A wind measuring device is installed at 2D-4D in front of the wind turbines of the wind turbines in different wind direction sectors of the wind farm. The wind measurement data affected by the wake, and the wind resource software is used to calculate the power generation of each unit. It avoids the problem of inaccurate data and results due to the influence of wind turbine wakes when setting up wind measuring towers on the field, and provides more accurate data support for the possible follow-up technical transformation plans of the wind farm.

Description

A method for evaluating the power generation of an operating wind farm

technical field

The invention belongs to the technical field of wind turbines, and in particular relates to a method for evaluating the power generation of a running wind farm.

Background technique

After the wind farm is put into operation, sometimes the power generation is low and the expected income cannot be achieved. Therefore, the owner hopes to improve the wind power by means of moving the machine, increasing the tower, replacing the long blade or "upper-larger and lower". field power generation. Before issuing a retrofit plan, sometimes due to problems such as missing or insufficient representation of the early wind tower data, it is necessary to re-measure the wind to evaluate the power generation after the retrofit. The existing wind farm power generation assessment methods are usually based on the data of the wind measurement tower in the wind farm before the wind turbine is erected. However, since the wind turbines have been arranged in the operating wind farm, the installation of the wind measurement tower in the wind farm will inevitably be affected by the wake of the wind turbine. Makes the final prediction result inaccurate.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method for evaluating the power generation of a wind farm in operation, so as to solve the problem that in the prior art, fans have been arranged in the operating wind farm, and the wind measurement tower installed in the field will inevitably be affected by the wake of the fan, so that the final The problem of inaccurate prediction results.

To achieve the above object, the present invention adopts the following technical solutions:

A method for evaluating the power generation of a wind farm in operation, comprising the following steps:

Divide the wind farm into four directions, and use wind measuring equipment to obtain wind speed and wind direction data in the four directions of the wind farm;

Import the wind speed and wind direction data into the wind resource software, and use the wind measurement data to correct the terrain or parameters of the wind resource software;

Create a transfer function by using the wind speed and wind direction of the wind measuring device, and the wind speed and wind direction of the engine room, and use the transfer function to correct the wind speed and wind direction of the engine room;

Carrying out a weighted average of the corrected wind direction of the engine room to obtain brand-new wind direction data, re-dividing the wind farm into four sectors according to the brand-new wind direction data, and obtaining the corrected wind speed and wind direction data of the engine room in each sector;

The corrected wind speed and wind direction data in each sector are imported into the wind resource software for simulation calculation, and the power generation at each position of the wind farm is obtained respectively. Terrain and parameters corrected from measured data.

Optionally, the wind farm is divided into four directions according to angles of -45° to 45°, 45° to 135°, 135° to 225°, and 225° to 315°.

Optionally, the specific method for obtaining wind speed and wind direction data in four directions of the wind farm by using wind measuring equipment is as follows:

Perform a terrain assessment on the outermost units in the four directions of the wind farm to determine whether it is a complex terrain;

If it is a platform terrain, select one unit in each of the four directions of the wind farm, and install the wind measuring equipment at the 2D-4D position of the upwind direction of the selected unit for wind measurement, and D is the diameter of the wind turbine rotor of the wind turbine;

If it is a complex terrain, perform CFD simulation on the wind farm. According to the simulation results, select a unit with the best correlation between wind speed and wind direction at the 2D-4D position of the upwind direction and the position of the wind turbine in each of the four directions of the wind farm. , install wind measurement equipment for wind measurement.

Optionally, if the terrain is complex, the wind measurement data measured by the wind measurement equipment is also corrected by using the relationship between the wind speed and wind direction at the position of the wind measurement equipment obtained by CFD simulation and the wind speed and wind direction at the position of the fan.

Optionally, the wind measurement equipment includes a wind measurement tower, a vertical lidar, and a cabin radar.

Optionally, the data collection time of the wind measuring device is at least one month.

Optionally, the wind resource software includes WT, WindSim, WAsP or WindPro.

Optionally, the transfer function is obtained by linear fitting; or first, the wind speed is averaged according to the wind speed of 0.5m/s as an interval, and then the average value of each two adjacent wind speed intervals is connected, and the obtained straight line is the Interval transfer function.

The beneficial effects of the present invention are as follows:

In the method for evaluating the power generation of a running wind farm provided by the embodiment of the present invention, a wind measuring device is installed at 2D-4D in front of the wind turbines of the wind turbines in different wind direction sectors of the wind farm. The wind measurement data affected by the wake, and the wind resource software is used to calculate the power generation of each unit. It avoids the problem of inaccurate data and results due to the influence of wind turbine wakes when setting up wind measuring towers on the field, and provides more accurate data support for the possible follow-up technical transformation plans of the wind farm.

Description of drawings

The accompanying drawings forming a part of the present application are used to provide further understanding of the present invention, and the exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

FIG. 1 is a flowchart of a method for evaluating the power generation of a wind farm in operation according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of the installation of the wind measuring equipment in the embodiment of the present invention.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. It should be noted that the embodiments in the present application and the features of the embodiments may be combined with each other in the case of no conflict.

The following detailed descriptions are all exemplary descriptions and are intended to provide further detailed descriptions of the present invention. Unless otherwise specified, all technical terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing specific embodiments only, and is not intended to limit the exemplary embodiments according to the present invention.

As shown in FIG. 1 , the present invention provides a method for evaluating the power generation of a wind farm in operation, and the specific method is as follows:

1) Divide the wind farm into four directions.

As an example, in this embodiment, it can be set uniformly according to on-site conditions, for example, it can be set to -45°˜45°, 45°˜135°, 135°˜225°, 225°˜315°.

2) As shown in Figure 2, terrain evaluation is performed on the outermost units in the four directions of the wind farm to determine whether it is a complex terrain.

Optionally, if it is a platform terrain, select a unit with the best wind measurement equipment installed in the four directions of the wind farm in the 2D-4D upwind direction for wind measurement. The wind measurement data is the wind direction and wind speed data at the fan hub. Among them, D is the diameter of the wind turbine rotor.

Optionally, if the terrain is complex, first perform CFD simulation on the wind farm. After the CFD simulation is completed, select one wind farm in each of the four directions of the wind farm. The wind speed and wind direction at the 2D-4D position of the upwind direction are related to the wind speed and direction of the wind turbine. The wind measurement is performed by a unit with the best performance and where wind measurement equipment can be placed. At the same time, the relationship between the wind speed and direction at the location of the wind measuring device and the wind speed and direction at the location of the fan, which is obtained by CFD simulation, is used to correct the measured wind data measured by the wind measuring device, so that the measured wind data measured by the wind measuring device can represent the wind turbine. Wind measurement data at the hub.

As an example, the wind measurement equipment includes, but is not limited to, wind towers, vertical lidars, cabin radars, and the like.

3) After installing the wind measuring equipment in four directions, the wind measuring equipment will carry out data collection, and its data collection time should be at least one month. After the data is completed, import the measured data into the wind resource software for simulation calculation, and import 2-3 wind measurement equipment data in batches to reverse the wind speed data of the other 1-2 wind measurement positions. And compare the simulated data with the measured data. If the error is large, adjust the terrain or parameters in the wind resource software until the simulated data is consistent with the measured data.

As an example, the wind resource software includes, but is not limited to, WT, WindSim, WAsP, or WindPro, and the like.

4) The transfer function of wind speed and wind direction is established by using the wind speed and wind direction of the wind measuring tower equipment and the fan at the same time.

Specifically, the creation of the wind speed transfer function can be performed by linear fitting as required, or the wind speed can be averaged according to the wind speed of 0.5m/s as an interval, and then connected by the average value of each two adjacent wind speed intervals. The straight line is is the transfer function of this interval. The wind direction transfer function can also be obtained by linear fitting or averaged in an interval of 10°.

As an example, the relationship finally obtained by linear fitting is Y=k*X+b.

As an example, the calculation formula of the corrected wind speed V _free obtained by the interval method is:

where:

V _nacelle,i and V _{nacelle,i+1 ——the} interval average of the wind speed in the engine room in interval i and interval i+1;

V _free,i and V _free,i+1 ——the interval average of the wind measuring equipment in interval i and interval i+1;

V _nacelle — the measured value of the cabin anemometer;

V _{free ——The} corrected free flow wind speed obtained by using the measured wind speed of the engine room and the wind speed of the wind measuring equipment.

5) Collect the SCADA data of the four units in the past year, and use the engine room wind speed and wind direction transfer function to correct the engine room wind speed and wind direction. Combine the corrected wind speed and wind direction of the cabin according to the data at the same time. The wind directions of the four units are weighted to obtain a new wind direction data. According to this wind direction data, the wind farm is divided into the four sectors in step 1), and sorted to reach the corrected four units in each sector. Cabin wind speed and wind direction data.

6) Import the corrected wind speed and wind direction data in the engine room of the four units into the wind resource software for simulation calculation, and obtain the power generation of each wind turbine in the wind farm. The terrain data and parameters should be consistent with the corrected data in step 3). The final estimated annual power generation of each wind turbine in the wind farm is equal to the sum of the resulting power generation calculated from the nacelle wind speed and wind direction data in the four sectors.

It is known from the technical common sense that the present invention can be realized by other embodiments without departing from its spirit or essential characteristics. Accordingly, the above-disclosed embodiments are, in all respects, illustrative and not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are encompassed by the present invention.

Claims (8)

1. A method for evaluating the power output of a running wind farm, comprising the steps of: Divide the wind farm into four directions, and use wind measuring equipment to obtain wind speed and wind direction data in the four directions of the wind farm; Import the wind speed and wind direction data into the wind resource software, and use the wind measurement data to correct the terrain or parameters of the wind resource software; Create a transfer function by using the wind speed and wind direction of the wind measuring device, and the wind speed and wind direction of the engine room, and use the transfer function to correct the wind speed and wind direction of the engine room; Carrying out a weighted average of the corrected wind direction of the engine room to obtain brand-new wind direction data, re-dividing the wind farm into four sectors according to the brand-new wind direction data, and obtaining the corrected wind speed and wind direction data of the engine room in each sector; The corrected wind speed and wind direction data in each sector are imported into the wind resource software for simulation calculation, and the power generation at each position of the wind farm is obtained respectively. Terrain and parameters corrected from measured data. 2 . The method for evaluating the power generation of a wind farm in operation according to claim 1 , wherein the wind farm is classified according to -45°～45°, 45°～135°, 135°～225°, 225°～315° The angle is divided into four directions. 3. The method for evaluating the power generation of a running wind farm according to claim 1, wherein the specific method for obtaining wind speed and wind direction data in four directions of the wind farm by using wind measuring equipment is as follows: Perform a terrain assessment on the outermost units in the four directions of the wind farm to determine whether it is a complex terrain; If it is a platform terrain, select one unit in each of the four directions of the wind farm, and install the wind measuring equipment at the 2D-4D position of the upwind direction of the selected unit for wind measurement, and D is the diameter of the wind turbine rotor of the wind turbine; If it is a complex terrain, perform CFD simulation on the wind farm. According to the simulation results, select a unit with the best correlation between wind speed and wind direction at the 2D-4D position of the upwind direction and the position of the wind turbine in each of the four directions of the wind farm. , install wind measuring equipment for wind measurement. 4. The method for evaluating the power output of a wind farm in operation according to claim 3, wherein if it is a complex terrain, wind speed, wind direction and wind speed at the position of the fan are also utilized at the position of the wind measuring equipment obtained by CFD simulation. The relationship of the wind direction corrects the wind data measured by the wind measuring equipment. 5 . The method for evaluating the power generation of a running wind farm according to claim 1 , wherein the wind measuring equipment comprises a wind measuring tower, a vertical laser radar and a nacelle radar. 6 . 6 . The method for evaluating the power generation of a running wind farm according to claim 1 , wherein the data collection time of the wind measuring device is at least one month. 7 . 7 . The method for evaluating the power output of an operating wind farm according to claim 1 , wherein the wind resource software comprises WT, WindSim, WAsP or WindPro. 8 . 8. The method for evaluating the power generation of a running wind farm according to claim 1, wherein the transfer function is obtained by linear fitting; The average values of two adjacent wind speed intervals are connected, and the resulting straight line is the transfer function of the interval.

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