Floating wind power generation system, floating wind power generation method, and floating wind power generation program

Abstract

To provide a floating wind power generation system, a floating wind power generation method, and a floating wind power generation program which enable earlier determination of a movement position and allow for greater power output.SOLUTION: A floating wind power generation system according to an embodiment of the present invention includes: a plurality of wind power generators floated on water by floating bodies; an acquisition section configured to acquire position information of the wind power generators, wind direction information on water, and wind speed information on water; a storage section configured to store a layout table that defines positions of the wind power generators with respect to wind direction and wind speed, obtained by prior measurement or calculation; a reference section configured to refer to the layout table based on measured values or predicted values of wind direction and wind speed; and a determination section configured to determine layout information that defines positions of the wind power generators in accordance with the information referred to in the layout table. For wind speeds within a predetermined range, the layout table defines the positions of the wind power generators using a constant wind speed value.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] Embodiments of the present invention relate to offshore wind power generation technology.

Background Art

[0002] There is a phenomenon called wind turbine wake in which the power generation output of a downstream wind power generation device decreases due to the influence of an upstream wind power generation device. Conventionally, in an offshore wind farm where a wind power generation device is floated on the ocean using a floating body, there is a technique of winding up the mooring cable of the wind power generation device with a winding device to adjust its position so that the downstream wind power generation device is not installed directly behind the upstream wind power generation device (Patent Document 1).

[0003] Also, there is a known technique of configuring the wind power generation device to move according to a set of parameters including the wind direction in order to minimize the aerodynamic wind turbine wake (Patent Documents 2 and 3). Furthermore, there is a known technique that combines an optimization method and a numerical analysis method to determine the arrangement of wind turbines (Non-Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Non-Patent Documents

[0005]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in order to make the wind turbine wake smaller, if the number of parameters including the wind direction is increased, or if parameters such as the wind direction are predicted or estimated more accurately, the time required to determine the moving destination position of the wind power generation device increases, and the time during which power can be generated at the optimal position after the wind power generation device moves decreases, resulting in a decrease in the power generation output.

[0007] The problem to be solved by the present invention is to determine the moving position in a shorter time and obtain more power generation output when moving the wind power generation device so as to suppress the decrease in the power generation output caused by the influence of the wind turbine wake, and to provide an offshore wind power generation system, an offshore wind power generation method, and an offshore wind power generation program.

Means for Solving the Problems

[0008] The off - shore wind power generation system according to an embodiment of the present invention includes a plurality of wind power generation devices floating on water by a floating body, a position information acquisition unit that acquires position information indicating the position of the wind power generation device from position measurement equipment that measures the position of the wind power generation device, a wind direction information acquisition unit that acquires wind direction information indicating the wind direction from at least one wind vane that measures the wind direction on water, a wind speed information acquisition unit that acquires wind speed information indicating the wind speed from at least one anemometer that measures the wind speed on water, a storage unit that stores a layout table that determines the position of the wind power generation device for wind directions and wind speeds obtained by prior measurement or calculation, a reference unit that refers to the layout table based on the measured values or predicted values of the wind direction and wind speed, and a determination unit that determines layout information for determining the position of the wind power generation device according to the information obtained by referring to the layout table. It is provided with, and in the layout table, for a wind speed within a predetermined range, the position of the wind power generation device is determined using a constant wind speed value.

Advantages of the Invention

[0009] According to an embodiment of the present invention, an off - shore wind power generation technology is provided that can suppress a decrease in power generation output caused by the influence of the windmill wake.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

[0011] Hereinafter, an offshore wind power generation system, an offshore wind power generation method, and an offshore wind power generation program according to embodiments of the present invention will be described in detail with reference to the drawings. Note that the embodiments shown below are examples of embodiments of the present invention, and the present invention is not construed as being limited to these embodiments. Also, in the drawings referred to in this embodiment, the same or similar reference numerals are given to the same or parts having similar functions, and repeated descriptions thereof may be omitted. Further, the dimensional ratios in the drawings may differ from the actual ratios for convenience of explanation, or a part of the configuration may be omitted from the drawings.

[0012] (First Embodiment) Hereinafter, embodiments of an offshore wind power generation system, an offshore wind power generation method, and an offshore wind power generation program will be described in detail with reference to the drawings. First, the first embodiment will be described with reference to FIGS. 1 to 8.

[0013] FIG. 1 is a perspective view showing the overall configuration of the off-shore wind power generation system according to the first embodiment. Reference numeral 1 in FIG. 1 denotes the off-shore wind power generation system according to the first embodiment. This off-shore wind power generation system 1 includes a plurality of off-shore wind power generation devices 2 floating on the open sea 3. The off-shore wind power generation device 2 uses the force of the wind W to rotate a windmill and generates electricity by its rotational motion. By arranging a large number of off-shore wind power generation devices 2 in a stand of forest, an off-shore wind farm is constructed. For example, in a plan view, the distance between each of the off-shore wind power generation devices 2 is arranged in a grid pattern at equal intervals.

[0014] Here, there is a phenomenon called a windmill wake in which the power generation output of the downstream (downwind side) off-shore wind power generation device 2 decreases due to the influence of the upstream (upwind side) off-shore wind power generation device 2. In an off-shore wind farm, the influence of power generation loss due to the windmill wake is large, and the power generation output decreases. In particular, in the off-shore wind farms planned in Japan, compared with the off-shore wind farms in Europe, the distance between the off-shore wind power generation devices 2 is short, and the risk of the windmill wake becomes high.

[0015] In the off-shore wind power generation system 1 of the present embodiment, at least a part of the off-shore wind power generation devices 2 move, and the layout in a plan view of the off-shore wind power generation devices 2 (see FIG. 3) can be appropriately changed. By setting an optimal layout according to the wind conditions, it is possible to suppress a decrease in the power generation output caused by the influence of the windmill wake. In addition, a power generation output along the power generation plan can be obtained.

[0016] FIG. 2 is a side view showing an off-shore wind power generation device and a wind condition observation device. As shown in FIG. 2, the off-shore wind power generation device 2 includes, as an off-shore facility, a plurality of blades 5 that rotate about a hub 4 as a central axis. When the wind W hits these blades 5, they rotate about the hub 4 as a central axis. Inside the nacelle 6, a generator 15 that is linked to the rotation of the hub 4 and generates electricity by the rotational force of the hub 4 is provided. In the present embodiment, an upwind type propeller type windmill that is a lift type windmill and a horizontal axis windmill is exemplified.

[0017] Inside the hub 4, a variable pitch mechanism (not shown) for changing the pitch angle of the blade 5 is provided. Also, inside the nacelle 6, a brake device (not shown) and the like are provided, and a speed increaser (not shown) may be provided. Further, an azimuth changing mechanism (not shown) for changing the azimuth of the nacelle 6 is provided. The change in the azimuth of the nacelle 6 is a rotation about the vertical axis of rotation. The angle of this rotation is called the yaw angle. That is, by changing the yaw angle, the azimuth of the nacelle 6 is changed. This nacelle 6 is provided at the upper part of the tower 7 standing on the ocean 3.

[0018] In addition, as underwater equipment, the offshore wind power generation device 2 includes a floating body 8 for floating the tower 7 on the ocean 3, a mooring cable 9 for mooring the floating body 8, and a power transmission cable 10 for sending the generated power to land.

[0019] The mooring cable 9 is a huge metal chain that connects and fixes the floating body 8 to the seabed. A plurality of mooring cables 9 are provided for one floating body 8. The lower ends of these mooring cables 9 are fixed to the seabed, and the offshore wind power generation device 2 does not need to be washed away by the ocean current even when it is floating on the floating body 8.

[0020] In addition, the offshore wind power generation device 2 is not completely fixed in a fixed position by the mooring cable 9, but can move horizontally within a predetermined range. That is, the mooring cable 9 is adjusted to a length that allows the offshore wind power generation device 2 to move. The offshore wind power generation device 2 may include a winch (not shown) for winding and unwinding the mooring cable 9.

[0021] In addition, the offshore wind power generation device 2 includes a moving device 11 for moving the offshore wind power generation device 2 horizontally. This moving device 11 is attached to the lower part of the floating body 8. The moving device 11 may be attached to the side or upper part of the floating body 8. Further, a plurality of moving devices 11 may be attached to the floating body 8.

[0022] The mobile device 11 is composed of, for example, a screw 12 for obtaining propulsion force in water, a motor (not shown) for driving the screw 12, a thrust change mechanism (not shown) for changing the direction of the screw 12, and the like. Note that the mobile device 11 may move the offshore wind power generation device 2 using other mechanisms other than the screw 12. Further, a winch (not shown) for winding and unwinding the mooring cable 9 may also serve as the mobile device.

[0023] Further, the mobile device 11 may not only move the offshore wind power generation device 2 horizontally but also cause the offshore wind power generation device 2 to yaw. That is, the change in the azimuth of the nacelle 6 can also be achieved by the rotational movement of the mobile device 11.

[0024] Also, although one floating body 8 is provided corresponding to one offshore wind power generation device 2, it is also possible to float a plurality of offshore wind power generation devices 2 on one floating body 8.

[0025] Further, the offshore wind power generation device 2 is provided with a position measurement device 13 for measuring the current position. For example, the position measurement device 13 is provided on the upper part of the nacelle 6 and measures the current position of the offshore wind power generation device 2 based on the radio wave received from the satellite positioning system.

[0026] The offshore wind power generation device 2 is also provided with a wind turbine control device 14. This wind turbine control device 14 is provided, for example, to control the azimuth of the nacelle 6, the pitch angle of the blade 5, the generator 15 provided in the nacelle, and the mobile device 11. Further, the wind turbine control device 14 is provided with a communication device (not shown). Then, the wind turbine control device 14 transmits the position information indicating the current position of the offshore wind power generation device 2 measured by the position measurement device 13 to the management computer 30 (see FIG. 5) at the headquarters in a remote location (ground station).

[0027] In this embodiment, an example is given of a mode in which the windmill control device 14 automatically controls the offshore wind power generation device 2, but other modes may also be possible. For example, the windmill control device 14 may receive an input operation from the administrator (user) of the offshore wind power generation system 1 and control the offshore wind power generation device 2. That is, the windmill control device 14 may also be a remote operation device for controlling the offshore wind power generation device 2 by manual operation of the administrator.

[0028] As shown in FIG. 1, the offshore wind power generation system 1 includes a plurality of wind condition observation devices 20 floating on the ocean 3. These wind condition observation devices 20 are provided for observing the wind direction and wind speed on the ocean 3.

[0029] As shown in FIG. 2, the wind condition observation device 20 includes a tower 21 standing on the ocean 3, a floating body 22 for floating the tower 21 on the ocean 3, and a mooring cable 23 for mooring the floating body 22. Further, the wind condition observation device 20 includes a wind vane 24 for measuring the wind direction on the ocean 3 and an anemometer 25 for measuring the wind speed on the ocean 3. The wind vane 24 and the anemometer 25 are provided at the upper part of the tower 21.

[0030] In this embodiment, the wind vane 24 and the anemometer 25 are provided in the wind condition observation device 20, but other modes may also be possible. For example, the wind vane 24 and the anemometer 25 may be provided in the offshore wind power generation device 2.

[0031] The wind condition observation device 20 is provided with a communication device (not shown). Then, the wind condition observation device 20 transmits wind direction information indicating the wind direction measured by the wind vane 24 and wind speed information indicating the wind speed measured by the anemometer 25 to the management computer 30 (FIG. 5) at the headquarters in a remote location (ground station).

[0032] The offshore wind power generation system 1 of this embodiment is composed of a management computer 30 that has hardware resources such as a CPU, ROM, RAM, and HDD, and information processing by software is realized using the hardware resources by the CPU executing various programs. Furthermore, the offshore wind power generation method of this embodiment is realized by causing the management computer 30 to execute various programs.

[0033] FIG. 3 is a plan view showing the layout of the offshore wind power generation device. As shown in FIG. 3, the reference position 2A of each offshore wind power generation device 2 is defined. The position 2B indicates, for example, an optimal position for suppressing a decrease in power generation output caused by the influence of the wind turbine wake.

[0034] FIG. 4 is a side view showing an offshore wind power generation system in which a wind turbine wake is occurring. As shown in FIG. 4, in addition to the horizontal wind W, in the offshore wind power generation device 2, there may be an air flow F flowing downward from above the layer L in the turbulent flow region T generated by the upstream offshore wind power generation device 2.

[0035] FIG. 5 is a block diagram showing the management computer of the first embodiment. Next, the system configuration of the management computer 30 will be described with reference to the block diagram shown in FIG. 5. This management computer 30 comprehensively manages the offshore wind power generation device 2 and the wind condition observation device 20.

[0036] The management computer 30 includes a communication unit 31, an input unit 32, an output unit 33, a storage unit 34, and a control unit 35. Note that each component of the management computer 30 does not necessarily need to be provided in one computer. For example, these components may be realized by a plurality of computers connected to each other via a network.

[0037] The communication unit 31 communicates with other computers via a communication line such as the Internet. For example, the communication unit 31 communicates with the water wind power generation device 2 and the wind condition observation device 20. In this embodiment, the management computer 30 and other computers are connected to each other via the Internet, but other modes may also be used. For example, the management computer 30 and other computers may be connected to each other via a WAN (Wide Area Network) or a mobile communication network.

[0038] Predetermined information is input to the input unit 32 according to the operations of an administrator (user) who uses the management computer 30. The input unit 32 includes an input device such as a mouse or a keyboard. That is, predetermined information is input to the input unit 32 according to the operations of these input devices.

[0039] The output unit 33 outputs predetermined information. The management computer 30 includes a device that displays an image such as a display that outputs an analysis result. That is, the output unit 33 controls the image displayed on the display. Note that the display may be separate from the computer main body or integrated with it.

[0040] Note that the management computer 30 of this embodiment may control the image displayed on the display provided in another computer connected via a network. In that case, the output unit 33 provided in another computer may control the output of the analysis result of this embodiment.

[0041] In this embodiment, a display is exemplified as the device that displays an image, but other modes may also be used. For example, a printer that prints information on a paper medium may be used instead of the display. That is, a printer may be included as the object controlled by the output unit 33.

[0042] The storage unit 34 stores various types of information necessary for controlling the water wind power generation system 1. For example, the storage unit 34 stores position information, wind direction information, wind speed information, layout information, and the like.

[0043] The control unit 35 comprehensively controls the management computer 30. This control unit 35 includes a position information acquisition unit 36, a wind direction information acquisition unit 37, a wind speed information acquisition unit 38, a turbulence intensity calculation unit 39, a layout table reference unit 40, a power generation output calculation unit 41, a layout determination unit 42, and a movement cost calculation unit 43. These are realized by a program stored in a memory or HDD being executed by a CPU.

[0044] The position information acquisition unit 36 acquires position information from each of the offshore wind power generation devices 2. The wind direction information acquisition unit 37 acquires wind direction information from each of the wind condition observation devices 20. The wind speed information acquisition unit 38 acquires wind speed information from each of the wind condition observation devices 20. The turbulence intensity calculation unit 39 calculates the turbulence intensity on the downstream side of each of the offshore wind power generation devices 2 based on the wind direction information and the wind speed information.

[0045] The layout table reference unit 40 refers to the layout table and outputs layout information that maximizes the total increase in power generation output based on at least the wind direction information and the wind speed information, in addition to the position information of the offshore wind power generation device 2 acquired by each of the position information acquisition unit 36, the wind direction information acquisition unit 37, and the wind speed information acquisition unit 38. Note that the layout table reference unit 40 according to the present embodiment corresponds to the reference unit.

[0046] Here, the layout information is information for changing the layout of the offshore wind power generation device 2. The layout information includes, for example, a layout table that takes the wind direction and wind speed within a predetermined range as inputs and outputs the layout of the offshore wind power generation device 2, as shown in FIG. 6 described later. The details of the layout table will be described later.

[0047] Based on the generated layout information, the power generation output calculation unit 41 calculates, for example, the difference between the power generation output of the offshore wind power generation device 2 at the current position (see 2A in FIG. 3, for example) and the power generation output of the offshore wind power generation device 2 at the position (see 2b in FIG. 3, for example) when the offshore wind power generation device 2 is moved according to the layout information as the increase amount of the output.

[0048] The layout determination unit 42 determines layout information that at least determines the position of the wind power generation device according to the information referring to the layout table. Note that the layout determination unit 42 according to the present embodiment corresponds to the determination unit.

[0049] For example, when at least a part of the offshore wind power generation devices 2 move based on the generated layout information, the layout determination unit 42 compares the total increase amount of the power generation output of each offshore wind power generation device 2 with the cost required when moving the offshore wind power generation device 2. When the total exceeds a predetermined value, the layout determination unit 42 determines layout information that at least determines the position of the wind power generation device 2 after the movement. When determining the movement, the layout determination unit 42 transmits a control signal including the layout information to the windmill control device 14 (see FIG. 2) of the offshore wind power generation device 2 via the communication unit 31. The windmill control device 14 executes control to move the wind power generation device 2 to the position included in the layout information for the moving device 11 (see FIG. 2).

[0050] The movement cost calculation unit 43 calculates the movement cost used by the layout determination unit 42 for the determination. This movement cost calculation unit 43 calculates the cost required when moving the offshore wind power generation device 2 based on the generated layout information. For example, it calculates the cost required for the movement from the current position (see 2A in FIG. 3, for example) to the position (see 2b in FIG. 3, for example) when the offshore wind power generation device 2 is moved according to the layout information.

[0051] Here, based on FIG. 6, the details of the layout table will be described. FIG. 6 is a diagram showing an example of a layout table that determines the layout pattern for wind direction and wind speed. The horizontal axis represents the wind speed, and the vertical axis represents the angle of the wind direction. The layout table is information indicating the position of the floating wind power generation device 2 after movement determined by the wind speed and the wind direction. This layout table also includes information on the position of the floating wind power generation device 2 when no movement is made. In addition, the layout table according to the present embodiment is defined by layout patterns 0 to 12 selected, for example, according to the wind speed and the wind direction.

[0052] At least the respective positions of the floating wind power generation device 2 (see FIGS. 1 and 3) are defined in layout patterns 0 to 12. Note that it is also possible to include the azimuth of each nacelle 6 of the floating wind power generation device 2 and the pitch angle of each blade 5 in each of the patterns 0 to 12.

[0053] For example, pattern 1 is in the range where the wind speed is approximately 5 m / s to 15 m / s and the wind direction is approximately 5 deg to 25 deg. In the case of wind direction and wind speed conditions within this range, the layout of pattern 1 is the optimal position.

[0054] In FIG. 6, there are 13 layout patterns from 0 to 12, but the number of patterns is arbitrary. Regarding the wind direction, the azimuth can be defined by equally dividing 360° in a full circle. For example, it may be divided into 16 azimuths at 22.5° intervals, but it may be divided more finely or more coarsely.

[0055] In the example of FIG. 6, in the range where the wind speed is 5 m / s or less and 15 m / s or more, and in the range where the wind direction is near 180 deg, since the influence of the wake on the wind direction and the wind speed is small, the floating wind power generation device 2 is not moved without changing the layout.

[0056] Note that the wind speed range at this time is described here as having a lower limit of 5 m / s and an upper limit of 15 m / s. However, since the appropriate value varies depending on conditions such as the wind turbine size and the distance between wind turbines, it is possible to set it according to the conditions of the wind farm. For example, as the upper limit value, a value close to the rated wind speed can be set.

[0057] As shown in FIG. 6, for the wind speed, it is possible to simplify by using a constant value for a certain range (for example, a lower limit of 5 m / s to an upper limit of 15 m / s). In FIG. 6, for example, the wind speed range is divided into a range where the wind speed is 0 to 5 m / s, a range where the wind speed is 5 to 15 m / s, and a range where the wind speed is 15 m / s or more. Here, for example, if the wind speed is in the range of 5 to 15 m / s, the positions of the offshore wind power generation devices 2 defined in Patterns 1 to 12 are set to constant values. In other words, the positions of the offshore wind power generation devices 2 defined in Patterns 1 to 12 in the wind speed range of 5 to 15 m / s are the same. In this way, for a predetermined range of wind speeds, the layout table determines the positions of the wind power generation devices 2 using a constant wind speed value according to the wind direction corresponding to the number of divisions.

[0058] FIG. 7 is a diagram showing an example of a table for determining the optimal yaw angle with respect to the wind direction and wind speed. In FIG. 6, the position of the offshore wind power generation device 2 was used as an example for explanation. In FIG. 7, an example including the yaw angle (nacelle azimuth) of the offshore wind power generation device 2 in Patterns 1 to 12 will be described. Note that numerical analysis including the position and yaw angle is feasible, but the example regarding the layout becomes complicated. Therefore, in FIG. 7, for the sake of simplicity of explanation, here, as an example of optimizing the operating conditions of the wind turbine with respect to the wind direction and wind speed, the result when the yaw angle (nacelle azimuth) is optimized by numerical analysis is shown. FIG. 7(a) is a diagram showing in a map form an example in which the wind direction and wind speed are finely divided based on the actual wind conditions, and the yaw angle is optimized at each point. The vertical axis represents the wind direction, and the horizontal axis represents the wind speed. The yaw angle is indicated by shading. In FIG. 7(a), the concentration indicating the yaw angle is increased in order from 0 degrees to 20 degrees.

[0059] As shown in Fig. 7(a), when the wind speed is in the range of 5 m / s to 15 m / s, for the same wind direction, the yaw angle is almost constant. This is because in the region with relatively low wind speed (the region with a large thrust coefficient), the dependence of power generation output on wind speed is low. Also, in the region where the wind speed is 15 m / s or more, various yaw angles are shown. However, in the high wind speed region (the region with a small thrust coefficient), the influence of the wake itself is small. Therefore, it is considered that even if the yaw angle is changed according to this table, the influence on the power generation output is small.

[0060] Fig. 7(b) is a diagram showing a simplified example in a map form considering the characteristics with respect to wind speed. The vertical axis represents the wind direction, and the horizontal axis represents the wind speed. The yaw angle is indicated by shading. In Fig. 7(a), the concentration indicating the yaw angle is increased in order from 0 degrees to 20 degrees. That is, Fig. 7(b) is different from Fig. 7(a) in that, considering the characteristics with respect to the wind speed as described above, representative values are used so that the wind speed is treated as constant in the relatively low wind speed range, and simplification is made so that control is not performed in the high wind speed region.

[0061] Fig. 7(c) is a diagram in which the generated power of the offshore wind power generation device 2 is calculated using the conditions shown in Fig. 7(a) and the conditions shown in Fig. 7(b). In Fig. 7(c), the generated power when there is no wake is shown as 1. Also, for the case where the wind turbines are arranged without optimization for the time being, the case where optimization is performed based on the actual wind conditions table, and the case where optimization is performed using the representative value of the wind speed, the generated power in each case is represented by a bar graph relatively showing the ratio of the generated power when there is no wake. As shown in Fig. 7(c), the generated power in the case where optimization is performed based on the actual wind conditions table and the case where optimization is performed using the representative value of the wind speed are almost the same value. It can be seen that optimization is performed with sufficient accuracy even when using the representative value for the wind speed. This is an example of optimization regarding the yaw angle. However, since it is considered that there is a similar effect in terms of the influence on the power generation output and the wake with respect to the wind direction and wind speed, it is considered that the same can be applied when determining the layout.

[0062] Here, an example of a method for generating a layout table will be described. For the installation location of the wind power generation system 1, the influence of the wind turbine wake and the interaction of the wind turbine wakes are calculated in advance under the assumed wind direction and wind speed conditions. This calculation may use computational fluid dynamics (CFD) or a predetermined engineering model (mathematical formula of the model). Furthermore, the atmospheric stability and the variation of the wind direction may be analyzed.

[0063] Also, when analyzing the influence of the wind turbine wake on the reference offshore wind power generation device 2, not only the influence of the wind turbine wake received from the offshore wind power generation device 2 upstream of the reference offshore wind power generation device 2, but also the influence of the wind turbine wake on the offshore wind power generation device 2 downstream of the reference offshore wind power generation device 2 is analyzed. Then, the optimal position of the reference offshore wind power generation device 2 (see 2B in FIG. 3 for example) is analyzed.

[0064] When determining the optimal position 2B of the offshore wind power generation device 2, the total reduction in the power generation output of each offshore wind power generation device 2 is minimized, but layout information for several patterns (for example, 100 patterns) may be generated, and the layout information with the minimum total reduction in the power generation output may be selected from among them. Also, iterative calculations may be performed until the layout information with the minimum total reduction in the power generation output is generated.

[0065] Note that when generating the layout information, calculations are performed with constraints such as the movable range defined by the mooring cable 9 and the range where the offshore wind power generation devices 2 do not interfere with each other.

[0066] In this way, a layout table is obtained that outputs the optimal position of the offshore wind power generation device 2 when the wind direction and wind speed are given. That is, in the layout table, the optimal position in the numerical analysis of the offshore wind power generation device 2 corresponding to the wind direction and wind speed is specified.

[0067] In this numerical analysis, as shown in FIG. 4, not only the flow of the horizontal wind W but also the flow of the vertical (up and down) wind W may be analyzed. For example, a turbulent flow region T that causes a wind turbine wake is formed on the rear side of a predetermined offshore wind power generation device 2.

[0068] Here, there may be a case where an air current F flows downward from an upper layer L above the turbulent flow region T generated by the upstream offshore wind power generation device 2. It is also possible to consider in the analysis the influence that the kinetic energy of this air current F has on the downstream offshore wind power generation device 2. For example, if the region with a high turbulence intensity of this air current F can be utilized, not only can the influence of the wind turbine wake be reduced, but the power generation output of the downstream offshore wind power generation device 2 may also be increased.

[0069] In this way, in addition to the wind direction and wind speed, it is also possible to create a layout table with the turbulence intensity as a parameter. In this case, as shown in FIG. 6, it is not a simple two-dimensional table on a single plane but a three-dimensional table. For example, for each value of the turbulence intensity, it has a two-dimensional table for the wind direction and wind speed, and generally becomes a complex table. However, as described above, for the wind speed, a certain range can be represented by a constant wind speed value. Therefore, for example, when it becomes a layout table as shown in FIG. 6 for the wind direction and wind speed, it is only necessary to create a table for the wind direction and turbulence intensity by dividing it into wind speeds of 5 m / s or less, 5 m / s to 15 m / s, and 15 m / s or more. Depending on the value of the turbulence intensity, the upper and lower limit values of the wind speed described above may change, but compared to the case of dividing the wind speed finely, the layout table to be stored can be less.

[0070] In addition, as the turbulence intensity increases, the influence of the wake becomes smaller. Therefore, for a turbulence intensity above a predetermined value, it is possible to create a layout table so that the offshore wind power generation device 2 does not move. The threshold value of the turbulence intensity in this case varies depending on the distance between wind turbines and the like, and thus it is possible to set it according to the conditions (wind farm conditions) under which the offshore wind power generation device 2 is arranged.

[0071] Furthermore, it is also known that the influence of the time change of the wind direction on the wake is significant. Numerical calculation results show that when the time change of the wind direction is large, the effect of yaw optimization, which is one of the wake countermeasures, cannot be fully obtained (see Non-Patent Document 2). For this reason, for example, a layout table using the standard deviation of the wind direction as a parameter can also be created.

[0072] Again, as shown in FIG. 3, first, it is assumed that there is a reference position 2A for each offshore wind power generation device 2. Here, it is assumed that the wind W is blowing from a predetermined direction, and the wind direction and wind speed of this wind W are observed by the wind condition observation device 20 (see FIG. 1). Based on this, the management computer 30 (see FIG. 5) obtains an optimal position 2B from the layout table in order to suppress the decrease in the power generation output caused by the influence of the wind turbine wake. Note that, regarding the wind direction and wind speed of the wind W, the measured value of the wind condition observation device at a representative position or the average value of the measured values of a plurality of wind condition observation devices may be used.

[0073] Then, the management computer 30 outputs layout information indicating the optimal position 2B of each offshore wind power generation device 2. Each offshore wind power generation device 2 controls the moving device 11 (see FIG. 2) based on the layout information and moves to the optimal position 2B.

[0074] FIG. 8 is a flowchart showing a processing example of the offshore wind power generation method according to the first embodiment. Here, the offshore wind power generation method according to the first embodiment will be described with reference to the flowchart of FIG. 8. Appropriate reference will be made to the above-mentioned drawings. The following steps are at least a part of the processing included in the offshore wind power generation method, and other steps may be included in the offshore wind power generation method.

[0075] First, in step S1, the position measuring device 13 (see FIG. 2) of each offshore wind power generation device 2 measures the current position. Here, the wind turbine control device 14 (see FIG. 2) transmits position information indicating the current position measured by the position measuring device 13 to the management computer 30 (see FIG. 5). Then, the process proceeds to step S4.

[0076] In step S2, which is executed in parallel with step S1, the wind vane 24 (see FIG. 2) of each wind condition observation device 20 measures the wind direction on the ocean 3. Here, the wind condition observation device 20 transmits wind direction information indicating this wind direction to the management computer 30. Then, it proceeds to step S5.

[0077] In step S3, which is executed in parallel with step S1, the anemometer 25 (see FIG. 2) of each wind condition observation device 20 measures the wind speed on the ocean 3. Here, the wind condition observation device 20 transmits wind speed information indicating this wind speed to the management computer 30. Then, it proceeds to step S6.

[0078] In step S4, the position information acquisition unit 36 (see FIG. 5) of the management computer 30 acquires position information from each offshore wind power generation device 2. Then, it proceeds to step S8.

[0079] In step S5, the wind direction information acquisition unit 37 (see FIG. 5) of the management computer 30 acquires wind direction information from each wind condition observation device 20. Then, it proceeds to steps S7 and S8.

[0080] In step S6, the wind speed information acquisition unit 38 (see FIG. 5) of the management computer 30 acquires wind speed information from each wind condition observation device 20. Then, it proceeds to steps S7 and S8.

[0081] In step S7, the turbulence intensity calculation unit 39 (see FIG. 5) of the management computer 30 calculates the turbulence intensity on the downstream side of each offshore wind power generation device 2 based on the wind direction information and the wind speed information. Then, it proceeds to step S8.

[0082] In step S8, the layout table reference unit 40 (see FIG. 5) of the management computer 30 refers to a pre-created layout table based on at least the wind direction information and the wind speed information in addition to the position information of each of the offshore wind power generation devices 2. Then, in step S9, the layout table reference unit 40 outputs layout information that maximizes the total increase in power generation output and proceeds to step S10.

[0083] Additionally or alternatively, the windmill wake evaluation unit 40 refers to the layout table based on the position information of each of the offshore wind power generation devices 2, the wind direction information, the wind speed information, and the turbulence intensity. In this way, the layout information can be determined including the turbulence intensity.

[0084] In the next step S10, the power generation output calculation unit 41 calculates, as the increase amount of the output, the difference between the power generation output of the offshore wind power generation device 2 at the current position (see 2A in FIG. 3, for example) and the power generation output of the offshore wind power generation device 2 at the position (see 2b in FIG. 3, for example) when the offshore wind power generation device 2 is moved according to the layout information, based on the generated layout information.

[0085] In the next step S11, the movement cost calculation unit 43 calculates the cost required when moving the offshore wind power generation device 2 from the current position based on the generated layout information. This cost includes the power when moving the offshore wind power generation device 2 using electricity, the fuel cost when moving it using a prime mover, the power required by the winch when winding or unwinding the mooring cable 9 (see FIG. 2), the power generation output in the power generation opportunity lost when stopping the offshore wind power generation device 2 during movement, and the like.

[0086] Next, in step S12, the layout determination unit 42 compares the total increase in the power generation output of the water-based wind power generation device 2 calculated by the power generation output calculation unit 41 with the cost required when moving the water-based wind power generation device 2 calculated by the movement cost calculation unit 43, and determines whether to move or not (step S12). When the layout determination unit 42 determines that the total increase in the power generation output exceeds a predetermined increase amount (YES in step S12), it proceeds to step S13.

[0087] On the other hand, when it is determined that the increase amount does not exceed the predetermined increase amount (NO in step S12), the processes from step S1 to step S3 are repeated.

[0088] In step S13, the wind turbine control device 14 (Fig. 2) of each water-based wind power generation device 2 executes a wind turbine movement process. Here, each wind turbine control device 14 controls the moving device 11 to move the position of the water-based wind power generation device 2 to an appropriate position according to the layout information. In this way, the water-based wind power generation device 2 can be moved to a position where a decrease in the power generation output is suppressed.

[0089] Note that the wind turbine movement process is a process of moving at least a part of the water-based wind power generation devices 2. Further, the wind turbine movement process may include control of the azimuth of the nacelle 6 called yaw control, control of the pitch angle of the blade 5 called pitch angle control, and control of the pitch angle of the blade 5 and the generator called induction control. Then, the processes from step S1 to step S3 are repeated.

[0090] In the first embodiment, by repeating steps S1 to S13, it is possible to minimize the decrease amount when the power generation output decreases due to the influence of the wind turbine wake.

[0091] In the water-based wind power generation method of the first embodiment, the wind turbine control device 14 moves the water-based wind power generation device 2 based on the layout information output by the management computer 30, but other modes may also be used. For example, based on the layout information output by the management computer 30, the user may move the water-based wind power generation device 2 by remote control. That is, the water-based wind power generation method of the first embodiment may be any method in which the management computer 30 executes at least the processes from step S4 to step S11.

[0092] In the first embodiment, the evaluation of the wind turbine wake is performed based on the wind direction information, the wind speed information, and the turbulence intensity, but other modes may also be used. For example, the evaluation of the wind turbine wake may be performed based only on the wind direction information and the wind speed information.

[0093] The direction in which the water-based wind power generation device 2 moves is preferably a direction perpendicular to the wind direction. In this way, the wind turbine wake can be avoided with a minimum moving distance. Further, when moving the upstream water-based wind power generation device 2, the downstream water-based wind power generation device 2 may be moved in the opposite direction to the upstream water-based wind power generation device 2. In this way, the wind turbine wake caused by the upstream water-based wind power generation device 2 can be avoided with a minimum moving distance.

[0094] If the overall power generation output of the water-based wind power generation system 1 decreases when a predetermined water-based wind power generation device 2 is moved, the predetermined water-based wind power generation device 2 may not be moved.

[0095] (Second Embodiment) Next, the second embodiment will be described with reference to FIGS. 9 to 10. The same reference numerals are given to the same components as those shown in the above-described embodiments, and redundant descriptions are omitted.

[0096] As shown in FIG. 9, the management computer 30 according to the second embodiment is different from the management computer 30 according to the first embodiment in that, in addition to the configuration of the aforementioned first embodiment (see FIG. 5), it further includes a wind condition prediction unit 44. This wind condition prediction unit 44 predicts the future wind direction and wind speed based on the wind direction information and wind speed information acquired by the management computer 30.

[0097] Next, the offshore wind power generation method of the second embodiment will be described using the flowchart of FIG. 10. The offshore wind power generation method of the second embodiment is different in that, in addition to the steps of the aforementioned first embodiment (see FIG. 8), steps S5A and S6A are added. Other steps are the same as those of the first embodiment. Appropriate reference is made to the block diagram shown in FIG. 9.

[0098] As shown in FIG. 10, in step S5A that follows step S5, the wind condition prediction unit 44 of the management computer 30 predicts the future wind direction. Then, it proceeds to steps S7 and S8.

[0099] In step S6A that follows step S6, the wind condition prediction unit 44 predicts the future wind speed. Then, it proceeds to steps S7 and S8.

[0100] In step S7, the turbulence intensity calculation unit 39 of the management computer 30 calculates the turbulence intensity on the downstream side of each offshore wind power generation device 2 based on the predicted wind direction and wind speed. That is, the future turbulence intensity is predicted. Then, it proceeds to step S8.

[0101] In step S8, the layout table reference unit 40 of the management computer 30 refers to the layout table based on the predicted wind direction, wind speed, and turbulence intensity in addition to the position information of each offshore wind power generation device 2. In this way, since the influence of the wind W actually hitting the offshore wind power generation device 2 can be predicted in advance, the reduction of the power generation output can be further suppressed.

[0102] For example, when the offshore wind power generation device 2 moves to an appropriate position based on the layout information, assume that it takes 10 minutes for the movement time. Here, the wind condition prediction unit 44 predicts the wind direction and wind speed 10 minutes after this movement time. Based on this prediction, the layout information is generated. If the offshore wind power generation device 2 starts moving, at the time when the movement is completed (10 minutes later), the wind direction and wind speed are exactly as predicted. Therefore, it is possible to sufficiently suppress the reduction of the power generation output. Also, by changing the layout in combination with the wind condition prediction, it is possible to predict the power generation output. In particular, the power generation output according to the power generation plan can be obtained.

[0103] In the second embodiment, by moving the offshore wind power generation device 2 according to the prediction of the wind direction and wind speed, it is possible to obtain the power generation output as per the power generation plan.

[0104] In the second embodiment, the reference of the layout table is performed based on the prediction of the wind direction, the prediction of the wind speed, and the turbulence intensity, but other modes may also be possible. For example, the evaluation of the wind turbine wake may be performed based only on the prediction of the wind direction, or based on the prediction of the wind direction and the prediction of the wind speed.

[0105] (Third Embodiment) Next, the third embodiment will be described with reference to FIGS. 11 to 12. Note that the same components as those shown in the above-described embodiments are denoted by the same reference numerals, and redundant descriptions are omitted.

[0106] As shown in FIG. 11, the management computer 30 of the third embodiment is different in that, in addition to the configuration of the second embodiment described above (see FIG. 9), it further includes a wind direction change calculation unit 45. This wind direction change calculation unit 45 predicts the wind direction change that will occur later based on the future wind direction predicted by the management computer 30.

[0107] Next, the offshore wind power generation method of the third embodiment will be described with reference to the flowchart of FIG. 12. The offshore wind power generation method of the third embodiment has step S5B added in addition to the steps of the aforementioned second embodiment (see FIG. 10). Other steps are the same as those of the second embodiment. Refer to the block diagram shown in FIG. 11 as appropriate.

[0108] As shown in FIG. 12, in step S5B that follows step S5A, the wind direction change calculation unit 45 of the management computer 30 predicts future wind direction changes. Then, it proceeds to step S8.

[0109] In step S8 that follows step S5B, the layout table reference unit 40 of the management computer 30 refers to the layout table based on the position information of each offshore wind power generation device 2, as well as the predicted wind direction, wind speed, turbulence intensity, and wind direction change. In this way, the influence of the wind W actually hitting the offshore wind power generation device 2 can be predicted more accurately considering the wind direction change, so that the reduction of the power generation output can be further suppressed.

[0110] In the third embodiment, according to the prediction of the wind direction and wind speed, by moving the offshore wind power generation device 2 to the position obtained considering the turbulence intensity and wind direction change as well, the power generation output as per the power generation plan can be obtained.

[0111] The offshore wind power generation system, offshore wind power generation method, and offshore wind power generation program have been described based on the first to third embodiments. However, the configurations applied in any one of the embodiments may be applied to other embodiments, or the configurations applied in each embodiment may be combined.

[0112] In the flowcharts of the above-described embodiments, the sequence relationship of each step is not necessarily fixed, and the sequence relationship of some steps may be interchanged. Also, some steps may be executed serially or in parallel with other steps.

[0113] In the above-described embodiment, the aspect where the floating wind power generation device 2 is provided on the ocean 3 is illustrated, but other aspects may also be possible. For example, the floating wind power generation device 2 may be provided on a lake. That is, the term "on water" includes the meanings of on the sea and on a lake.

[0114] In the above-described embodiment, as the floating wind power generation device 2, a lift-type windmill and an upwind-type propeller windmill with a horizontal axis are illustrated, but other aspects may also be possible. For example, the floating wind power generation device 2 may be a downwind-type propeller windmill. Also, the floating wind power generation device 2 may be a Darrieus windmill, a gyro mill, or a vertical wing windmill that is a lift-type windmill and a vertical axis windmill. Further, the floating wind power generation device 2 may be a Savonius windmill, a paddle windmill, a cross-flow windmill, or an S-shaped rotor windmill that is a drag-type windmill and a vertical axis windmill. Additionally, the floating wind power generation device 2 may be a Magnus windmill that is a lift-type windmill and a horizontal axis or vertical axis windmill.

[0115] In the above-described embodiment, the wind condition observation device 20 observes the wind direction and wind speed on the ocean 3, but other aspects may also be possible. For example, the floating wind power generation system 1 includes a plurality of aerial drones (not shown), and these aerial drones may observe the wind direction and wind speed on the ocean 3.

[0116] In the above-described embodiment, the layout of the floating wind power generation device 2 is changed when affected by the wind turbine wake, but other aspects may also be possible. For example, during a time period with low power consumption such as at night, even when affected by the wind turbine wake, the layout may not need to be changed. Also, based on a predetermined power generation plan, if sufficient power generation output can be obtained, even when affected by the wind turbine wake, the layout may not need to be changed.

[0117] In the above-described embodiment, the layout is determined based on the prediction of the wind direction or wind speed, but at that time, the predicted value of the power generation output may also be considered.

[0118] In the above-described embodiment, the wake within one offshore wind farm has been described, but it may also be applied to the wake that occurs between multiple wind farms.

[0119] The system of the above-described embodiment includes a control device with highly integrated processors such as a dedicated chip, FPGA (Field Programmable Gate Array), GPU (Graphics Processing Unit), or CPU (Central Processing Unit), a storage device such as ROM (Read Only Memory) or RAM (Random Access Memory), an external storage device such as HDD (Hard Disk Drive) or SSD (Solid State Drive), a display device such as a display, an input device such as a mouse or keyboard, and a communication interface. This system can be realized with a hardware configuration using a normal computer.

[0120] Note that the program executed in the system of the above-described embodiment is provided by being pre-embedded in a ROM or the like. Alternatively, this program may be stored in a computer-readable non-transitory storage medium such as a CD-ROM, CD-R, memory card, DVD, flexible disk (FD), etc. in an installable or executable file format and provided.

[0121] Also, the program executed in this system may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. Further, this system can also be configured by interconnecting and combining separate modules that independently perform the functions of the components with a network or a dedicated line.

[0122] According to at least one embodiment described above, a layout information for changing the layout of at least some of the wind power generation devices according to the evaluation of the windmill wake is referred to from the wind direction information and the wind speed information by using a layout table that determines the windmill positions using a constant wind speed value for a predetermined range of wind speeds, and by providing a layout table reference unit, the movement position can be determined in a shorter time.

[0123] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, changes, and combinations can be made without departing from the gist of the invention. These embodiments or their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and its equivalent scope.

Explanation of Reference Numerals

[0124] 1... Offshore wind power generation system, 2... Offshore wind power generation device, 3... Ocean, 4... Hub, 5... Blade, 6... Nacelle, 7... Tower, 8... Floating body, 9... Mooring cable, 10... Power transmission cable, 11... Moving device, 12... Screw, 13... Position measuring device, 14... Windmill control device, 15... Generator, 20... Wind condition observation device, 21... Tower, 22... Floating body, 23... Mooring cable, 24... Wind vane, 25... Anemometer, 30... Management computer, 31... Communication unit, 32... Input unit, 33... Output unit, 34... Storage unit, 35... Control unit, 36... Position information acquisition unit, 37... Wind direction information acquisition unit, 38... Wind speed information acquisition unit, 39... Turbulence intensity calculation unit, 40... Layout table reference unit, 41... Power generation output calculation unit, 42... Layout determination unit, 43... Movement cost calculation unit, 44... Wind condition prediction unit, 45... Wind direction change calculation unit, F... Airflow, L... Layer, T... Turbulence region, W... Wind.

Claims

1. A plurality of wind power generation devices floating on water by a floating body, a position information acquisition unit that acquires position information indicating the positions of the wind power generation devices from position measurement devices that measure the positions of the wind power generation devices, a wind direction information acquisition unit that acquires wind direction information indicating the wind direction from at least one wind vane that measures the wind direction on water, a wind speed information acquisition unit that acquires wind speed information indicating the wind speed from at least one anemometer that measures the wind speed on water, a storage unit that stores a layout table that determines the positions of the wind power generation devices for wind directions and wind speeds obtained by prior measurement or calculation, a reference unit that refers to the layout table based on the measured or predicted values of the wind direction and wind speed, a determination unit that determines layout information for determining the positions of the wind power generation devices according to the information obtained by referring to the layout table, comprising, in the layout table, for wind speeds within a predetermined range, the positions of the wind power generation devices are determined using a constant wind speed value, an offshore wind power generation system.

2. further comprising a moving device that moves at least some of the wind power generation devices according to the layout information, The offshore wind power generation system according to claim 1.

3. In the information of the layout table, for wind speeds equal to or higher than a predetermined value, it is determined that the positions of the wind power generation devices are not changed, The offshore wind power generation system according to claim 1.

4. further comprising a turbulence intensity calculation unit that calculates the turbulence intensity on the downstream side of at least one of the wind power generation devices based on the position information, the wind direction information, and the wind speed information, The determination unit further uses the turbulence intensity to determine the positions of the wind power generation devices. The offshore wind power generation system according to any one of claims 1 to 3.

5. The determination unit generates the layout information so that the positions of the wind power generation devices are not changed for turbulence intensities equal to or higher than a predetermined value obtained in the turbulence intensity calculation unit. The offshore wind power generation system according to claim 4.

6. The layout table is based on the time change of the wind direction obtained from the wind direction information to determine the positions of the wind power generation devices. The offshore wind power generation system according to claim 3.

7. The wind power generation device includes wind turbine blades, a generator that generates electric power by the rotation of the wind turbine blades, and a nacelle that houses the generator, Combined with controlling the pitch of the windmill blades, or induction control for controlling the rotational speed or power generation output of the generator, or controlling the azimuth of the nacelle, The offshore wind power generation system according to claim 3.

8. Based on the layout information, a power generation output calculation unit that calculates the difference between the power generation output of the offshore wind power generation device at the current position and the power generation output of the offshore wind power generation device at the position when the offshore wind power generation device 2 is moved according to the layout information as the increase amount of the output; A movement cost calculation unit that calculates the cost required when moving the offshore wind power generation device based on the layout information, and further includes: The determination unit outputs a control signal for moving the moving device to the windmill control device of the offshore wind power generation device when the increase amount is greater than or equal to a predetermined value than the cost. The offshore wind power generation system according to claim 2.

9. A step in which a position information acquisition unit acquires position information indicating the positions of a plurality of wind power generation devices floating on water by a floating body from position measurement devices that measure the positions of the wind power generation devices; A step in which a wind direction information acquisition unit acquires wind direction information indicating the wind direction from at least one wind vane that measures the wind direction on water; A step in which a wind speed information acquisition unit acquires wind speed information indicating the wind speed from at least one anemometer that measures the wind speed on water; A step in which a layout table reference unit refers to a layout table stored in a storage unit, in which the positions of the wind power generation devices with respect to the wind direction, wind speed, or turbulence intensity obtained by prior measurement or calculation are determined based on the position information, the wind direction information, and the wind speed information; Including, In the layout table, the windmill positions are determined using a constant wind speed value for a predetermined range of wind speeds. Offshore wind power generation method.

10. In a computer, A step of acquiring position information indicating the positions of a plurality of wind power generation devices floating on water by a floating body from position measurement devices that measure the positions of the wind power generation devices; A step of acquiring wind direction information indicating the wind direction from at least one wind vane that measures the wind direction on water; A step of acquiring wind speed information indicating the wind speed from at least one anemometer that measures the wind speed on water; Based on the position information, wind direction information, and wind speed information, determine the position of the wind power generation device with respect to the wind direction, wind speed, or turbulence intensity obtained by prior measurement or calculation, and refer to a layout table that determines the position of the wind power generation device using a constant wind speed value for wind speeds within a predetermined range. An offshore wind power generation program that causes the above to be executed.

Images