A device and method for measuring power characteristics of offshore wind turbines

Abstract

The present invention belongs to the technical field of offshore wind turbines, and discloses a device for measuring the power characteristics of offshore wind turbines, including a wind measuring device, a wave measuring device, a current measuring device, a current transformer, a power transmitter, a data collector and a wireless communication module; the current transformer is installed on the wind turbine, the current transformer is connected to the power transmitter, the wind measuring device, the wave measuring device, the current measuring device and the power transmitter are respectively connected to the data collector; the wave measuring device and the current measuring device are installed in the area around the wind turbine foundation; the data collector communicates with a remote host computer. The measurement method is also disclosed, in addition to wind, waves and currents are also used as factors affecting the wind turbine power curve, and the wind turbine power curve can be modeled more accurately, so that the power generation of the wind turbine can be accurately evaluated in the planning and design stage to optimize the layout of the unit, and the factors affecting the power generation of the wind turbine can be accurately evaluated in the production stage to optimize the operation control strategy of the wind turbine.

Description

Technical Field

[0001] The invention belongs to the technical field of offshore wind turbines, and specifically discloses a device and a method for measuring power characteristics of offshore wind turbines. Background Art

[0002] The offshore environment is harsh. In addition to being affected by wind, the power generation performance of wind turbines is also affected by factors such as waves and currents. Different wave and current directions and intensities will affect the control reliability and stability of the unit, thereby affecting the power characteristics of the unit. At present, the power characteristic test method of offshore wind turbines still uses the test method of onshore wind turbines, and only uses wind as an evaluation factor affecting the power output characteristics of the generator set, thereby reducing the reliability of the type certification of offshore wind turbines. This method not only makes it difficult for offshore wind turbines to often reach the optimal power curve, but also makes it difficult to fully optimize the control strategy of the wind turbine to increase the power generation of the unit. Summary of the invention

[0003] The purpose of the present invention is to provide a device and a method for measuring the power characteristics of an offshore wind turbine, which solves the problem that the optimal power curve of the offshore wind turbine cannot be obtained by using the test method of onshore wind turbines to test the offshore wind turbines.

[0004] The present invention is achieved through the following technical solutions:

[0005] A device for measuring power characteristics of offshore wind turbines, comprising a wind measuring device, a wave measuring device, a current measuring device, a current transformer, a power transmitter, a data collector and a wireless communication module;

[0006] The current transformer is installed on the wind turbine, the current transformer is connected to the power transmitter, and the wind measuring equipment, wave measuring equipment, current measuring equipment and power transmitter are respectively connected to the data collector;

[0007] Wave measuring equipment and current measuring equipment are installed in the area around the wind turbine foundation;

[0008] The data collector communicates with the remote host computer through the wireless communication module.

[0009] Furthermore, the wind measuring equipment includes a wind tower or a laser radar.

[0010] Furthermore, the flow measuring equipment includes a Doppler wave profiler or a buoy.

[0011] Furthermore, the area around the wind turbine foundation is: an area formed by a radial distance of 100m to 200m with the wind turbine foundation as the center.

[0012] Furthermore, the data measured by the wind measuring equipment includes meteorological data at the wind turbine hub height of 2D to 4D from the wind turbine in the main wind direction; wherein the main wind direction is the sector with the largest wind energy proportion and not exceeding 45° selected based on the annual wind energy rose diagram;

[0013] The data measured by the wave measuring equipment includes wave data of the area around the wind turbine foundation;

[0014] The data measured by the flow measuring equipment includes the water flow data in the area around the wind turbine foundation.

[0015] Furthermore, meteorological data include wind speed, wind direction, temperature, humidity and air pressure, wave data include wave height, wave direction and wave period, and water flow data include water flow velocity and water flow direction.

[0016] Furthermore, the wind measuring equipment, wave measuring equipment and current measuring equipment all have built-in GPS timing modules.

[0017] Furthermore, wind measuring equipment, wave measuring equipment, current measuring equipment and power transmitters continuously collect data at a sampling rate of 1 Hz or above.

[0018] The present invention also discloses a method for measuring the power characteristics of an offshore wind turbine generator system, comprising the following steps:

[0019] S1. Collect data using wind measuring equipment, wave measuring equipment and current measuring equipment;

[0020] S2. Eliminate the meteorological data, wave data and water flow data when the wind turbines, wind measuring equipment, wave measuring equipment and current measuring equipment are not operating normally, and the wind direction is not in the main wind direction period;

[0021] S3. Offshore wind turbines should standardize wind speed according to air density and convert wind speed to the same air density. After data standardization, average meteorological data, wave data and water flow data to obtain several sets of wave direction, flow direction and matching wind speed and power data points.

[0022] S4. Divide the statistical average values ​​of wave direction and flow direction into different sectors evenly in the range of 0° to 360°, take the sectors where the wave direction and flow direction are located as characteristic values, and assign the data sequences composed of meteorological data, wave data and water flow data at the same time to different wave direction and flow direction sectors to form meteorological data, wave data and water flow data groups under different wave direction and flow direction sectors. For different data groups, establish function models with wind speed, wave height, period and flow velocity as variables and power as dependent variable to form a function group for evaluating power characteristics of wind turbines.

[0023] Compared with the prior art, the present invention has the following beneficial technical effects:

[0024] The present invention discloses a device for measuring the power characteristics of offshore wind turbines, including a wind measuring device, a wave measuring device and a current measuring device. Meteorological data is obtained through the wind measuring device, wave data is obtained through the wave measuring device, and water flow data is obtained through the current measuring device. The wind measuring device, the wave measuring device and the current measuring device are all connected to a data collector, and the meteorological data, wave data and water flow data are sent to the data collector. The data collector then sends the data to a remote host computer through a communication module to provide a database for the background, which is convenient for subsequent analysis. Since waves and currents will affect the load of offshore wind turbines, this method, in addition to wind, also takes waves and currents as factors affecting the wind turbine power curve, and can more accurately model the wind turbine power curve, so that the power generation of the wind turbine can be accurately evaluated in the planning and design stage to optimize the layout of the unit, and the factors affecting the power generation of the wind turbine can be accurately evaluated in the production stage to optimize the wind turbine operation control strategy.

[0025] The present invention also discloses a measurement method based on the device for measuring the power characteristics of offshore wind turbines, which analyzes and calculates the collected meteorological data, wave data and water flow data to form a wind turbine power characteristic evaluation function group, which can be used to evaluate the power generation of offshore wind turbines, which is beneficial for owners to more accurately grasp the power generation income of offshore wind farms to be developed and the power characteristics of operating wind turbines, lays the foundation for the micro-site optimization of offshore wind farms and the operation optimization of offshore wind turbines, and is beneficial to improving the power characteristics of offshore wind turbines and optimizing the micro-site selection of offshore wind farms. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a schematic structural diagram of a device for measuring power characteristics of an offshore wind turbine generator system.

[0027] Among them, 1 is a current transformer, 2 is a power transmitter, 3 is a wave measuring device, 4 is a current measuring device, 5 is a wind measuring device, 6 is a wireless communication module, and 7 is a data collector. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0029] like Figure 1As shown, the present invention discloses a device for measuring power characteristics of offshore wind turbines, including a wind measuring device 5, a wave measuring device 3, a current measuring device 4, a current transformer 1, a power transmitter 2, a data collector 7 and a wireless communication module 6. The current transformer 1 is installed on the wind turbine, the current transformer 1 is connected to the power transmitter 2, the wind measuring device 5, the wave measuring device 3, the current measuring device 4 and the power transmitter 2 are respectively connected to the data collector 7, the data collector 7 is connected to the wireless communication module 6, and the wireless communication module 6 sends the data of the data collector 7 by wireless transmission.

[0030] Specifically, the current transformer 1 is installed on a cable between a generator and a converter of a wind turbine generator set. One end of the current transformer 1 is connected to the cable, and the other end is connected to the power transmitter 2 .

[0031] The wind measuring equipment 5 is installed on the platform, surrounding or cabin shell of the wind turbine depending on the type of equipment. The wind measuring equipment 5 includes but is not limited to a wind tower and a lidar. The wave measuring equipment 3 includes but is not limited to an acoustic Doppler wave meter. The flow measuring equipment 4 includes but is not limited to a Doppler wave profile flow meter.

[0032] Specifically, the wind turbine generator set includes a generator and a converter. The generator and the converter are connected via a cable. One end of the current transformer 1 is connected to the cable, and the other end is connected to the power transmitter 2 .

[0033] The wind measuring device 5 is installed on the platform, periphery or nacelle shell of the wind turbine generator set, and the specific installation position depends on the type of equipment.

[0034] The data measured by the wind measuring device 5 should include the meteorological data at the wind turbine hub height of 2D to 4D away from the wind turbine in the main wind direction, mainly including wind speed, wind direction, temperature, humidity and air pressure;

[0035] The data measured by the wave measuring device 3 should include wave data at different sections of 100 meters to 200 meters around the foundation of the wind turbine, and the wave data include wave height, wave direction, and period; the flow measuring device 4 should include water flow data at different sections of 100 meters to 200 meters around the foundation of the wind turbine, and the water flow data include flow velocity and flow direction.

[0036] Among them, each measuring device maintains time synchronization through the GPS timing module, and the maximum time difference of data collection synchronization of different devices should be less than 1% of the average time.

[0037] Preferably, the sampling rate is too low to accurately reflect the changes in wind, waves and currents, so the wind measuring device 5, the wave measuring device 3, the current measuring device 4 and the power transmitter 2 continuously collect data at a sampling rate of 1 Hz or above.

[0038] Among them, the main wind direction is the sector with the largest wind energy proportion and not exceeding 45°, which is selected based on the annual wind energy rose diagram.

[0039] The power characteristics evaluation process is as follows:

[0040] (1) Arrange and set up the wind measuring equipment 5, wave measuring equipment 3 and current measuring equipment 4 according to the above requirements. The data collection period of each device shall be at least one full year.

[0041] (2) The meteorological, wave and water flow data of wind turbines and measuring equipment that are not operating normally and the wind direction during non-main wind direction periods should be excluded, and the data should not be damaged.

[0042] It should be ensured that only data collected during normal operation of the wind turbine are used for analysis and that the data are not damaged. The data groups in the following cases should be removed from the database:

[0043] a) External conditions other than wind speed exceed the operating range of the wind turbine;

[0044] b) Wind turbine generator set failure causes wind turbine generator set shutdown;

[0045] c) Manual shutdown during testing or maintenance operation;

[0046] d) Failure or degradation of measuring instruments;

[0047] e) Data on whether the wind direction is in the main wind direction.

[0048] (3) Offshore wind turbines should standardize wind speed according to air density and convert wind speed to the same air density.

[0049] After data standardization, the meteorological data, wave data and water flow data are averaged using the “interval method” (e.g. 10 minutes) to obtain several sets of wave direction, flow direction and matching wind speed and power data points.

[0050] (4) The statistical average values ​​of the wave direction and flow direction are evenly divided into different sectors in the range of 0° to 360°. The sectors where the wave direction and flow direction are located are used as characteristic values. The data sequences composed of the meteorological data, wave data and water flow data at the same time are allocated to different wave direction and flow direction sectors to form meteorological data, wave data and water flow data groups under different wave direction and flow direction sectors (for example: if divided into 4 sectors, the sector angles are 0° to 90°, 90° to 180°, 180° to 270° and 270° to 360° respectively). For different data groups, function models are established with wind speed, wave height, period and flow velocity as variables and power as the dependent variable to form a function group for evaluating the power characteristics of wind turbines.

[0051] This function group can be used to evaluate the power generation of offshore wind turbines, which is beneficial for owners to more accurately grasp the power generation benefits of offshore wind farms to be developed and the power characteristics of operating wind turbines, laying the foundation for the micro-site optimization of offshore wind farms and the operation optimization of offshore wind turbines.

Claims

1. A method for measuring power characteristics of an offshore wind turbine generator system, characterized in that: The device comprises a wind measuring device (5), a wave measuring device (3), a current measuring device (4), a current transformer (1), a power transmitter (2), a data collector (7) and a wireless communication module (6); The current transformer (1) is installed on the wind turbine generator set, the current transformer (1) is connected to the power transmitter (2), and the wind measuring device (5), the wave measuring device (3), the current measuring device (4) and the power transmitter (2) are respectively connected to the data acquisition device (7); The wave measuring device (3) and the current measuring device (4) are installed in the area surrounding the wind turbine foundation; The data collector (7) communicates with the remote host computer via the wireless communication module (6); Wind measurement equipment (5) includes wind towers or laser radars; Current measuring equipment (4) includes Doppler wave profiler current meters or buoys; The area around the wind turbine foundation is: the area formed by the wind turbine foundation as the center and the radial distance of 100m-200m; The data measured by the wind measuring device (5) includes meteorological data at a height of the wind turbine hub 2D to 4D from the wind turbine in the main wind direction; wherein the main wind direction is the sector with the largest wind energy proportion and not exceeding 45° selected based on the annual wind energy rose diagram; The data measured by the wave measuring device (3) includes wave data of the area around the wind turbine foundation; The data measured by the flow measuring device (4) includes water flow data of the area around the wind turbine foundation; Meteorological data include wind speed, wind direction, temperature, humidity and air pressure; wave data include wave height, wave direction and wave period; water flow data include water flow velocity and water flow direction; The measurement method includes the following process: S1, collecting data using wind measuring equipment (5), wave measuring equipment (3) and current measuring equipment (4); S2, eliminating the meteorological data, wave data and water flow data of the wind turbine generator set, wind measuring equipment (5), wave measuring equipment (3) and current measuring equipment (4) in abnormal operation and the wind direction in the non-main wind direction time period; S3. Offshore wind turbines should standardize wind speed according to air density and convert wind speed to the same air density. After data standardization, average meteorological data, wave data and water flow data to obtain several sets of wave direction, flow direction and matching wind speed and power data points. S4. Divide the statistical average values ​​of wave direction and flow direction into different sectors evenly in the range of 0°-360°, take the sectors where the wave direction and flow direction are located as characteristic values, and assign the data sequences composed of meteorological data, wave data and water flow data at the same time to different wave direction and flow direction sectors to form meteorological data, wave data and water flow data groups under different wave direction and flow direction sectors. For different data groups, establish function models with wind speed, wave height, period and flow velocity as variables and power as dependent variable to form a function group for evaluating power characteristics of wind turbines.

2. The measuring method according to claim 1, characterized in that: The wind measuring device (5), the wave measuring device (3) and the current measuring device (4) all have built-in GPS time calibration modules.

3. The measuring method according to claim 1, characterized in that: The wind measuring device (5), the wave measuring device (3), the current measuring device (4) and the power transmitter (2) continuously collect data at a sampling rate of 1 Hz or more.

Images