Airflow generation device and wind power generator

Abstract

To provide a device that independently generates airflow and is easy to install.SOLUTION: An airflow generation device comprises: a dielectric layer; a first electrode disposed on a surface of the dielectric layer; a second electrode disposed on a back surface of the dielectric layer; a secondary battery for supplying power; a charging unit for charging the secondary battery; a drive unit for applying a voltage between the first electrode and the second electrode by receiving power supplied from the secondary battery; a control unit for controlling application of the voltage between the first electrode and the second electrode from the drive unit; and a base covering a back surface side of the dielectric layer. The secondary battery, the charging unit, the drive unit, and the control unit are disposed between the back surface of the dielectric layer and the base.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an airflow generating device and a wind power generator. [Background technology]

[0002] Patent Documents 1 and 2 disclose, for example, inventions for generating airflow on the blade surface of a wind turbine generator. In the airflow generating device disclosed in Patent Document 1, a main body that generates an airflow using plasma is disposed on the wind turbine blade, and a voltage application unit that applies voltage to the main body is disposed inside the wind turbine blade. This voltage application unit receives DC voltage converted from commercial AC voltage from the nacelle via a slip ring. The voltage application unit generates a high-frequency AC voltage from the supplied DC voltage, boosts the generated AC voltage, and then pulse-modulates the boosted AC voltage. When the voltage application unit applies the pulse-modulated AC voltage to the main body, a plasma airflow is generated in the main body, and this plasma airflow suppresses separated flow on the wind turbine blade.

[0003] Patent Document 2 discloses a plurality of plasma airflow generators arranged on the blades of a wind turbine. A plasma power supply consisting of multiple systems is connected to the plasma power supplies, and a low-voltage power supply is connected to each system of the plasma power supplies. The plasma power supplies generate a plasma voltage from an AC voltage of, for example, 100 V supplied from the low-voltage power supplies. When this plasma voltage is applied to the plasma airflow generator, a plasma airflow is generated, suppressing the separation flow around the blades. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-94934 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-225296 Summary of the Invention [Problem to be solved by the invention]

[0005] In the invention disclosed in Patent Document 1, the voltage application unit is disposed inside the wind turbine blade, so it is necessary to provide a space inside the wind turbine blade for disposing the voltage application unit. Furthermore, if an airflow generating device is retrofitted to a wind turbine blade, it is necessary to process the wind turbine blade and install the voltage application unit in the nacelle, which increases the cost of modifications. In the plasma airflow generating device disclosed in Patent Document 2, when a plasma power supply is installed inside the nacelle or inside the blade, it is also necessary to provide a space inside the blade or nacelle for disposing the plasma power supply. Furthermore, if a plasma airflow generating device is retrofitted to a blade, it is necessary to process the blade and install the plasma power supply in the nacelle, which increases the cost of modifications.

[0006] The present invention has been made in view of the above, and an object of the present invention is to provide a device that generates an airflow independently and is easy to install. [Means for solving the problem]

[0007] An airflow generating device according to one aspect of the present invention comprises a dielectric layer, a first electrode arranged on the surface of the dielectric layer, a second electrode arranged on the back surface of the dielectric layer, a secondary battery that supplies power, a charging unit that charges the secondary battery, a driving unit that receives power supplied from the secondary battery and applies a voltage between the first electrode and the second electrode, a control unit that controls the application of voltage from the driving unit to between the first electrode and the second electrode, and a base that covers the back surface of the dielectric layer, wherein the secondary battery, the charging unit, the driving unit, and the control unit are arranged between the back surface of the dielectric layer and the base.

[0008] In the airflow generation device according to the present invention, the dielectric layer and the base may be flexible.

[0009] In the airflow generation device according to the present invention, the base may be chamfered on the upstream side and downstream side of the airflow generated by applying a voltage between the first electrode and the second electrode.

[0010] In the airflow generation device according to the present invention, a solar cell that supplies power to the charging unit may be disposed on the surface of the base.

[0011] The airflow generating device according to the present invention may further include a sensor that measures the airflow on the surface side of the base, and the control unit may control the drive unit based on the measurement result of the sensor.

[0012] A wind power generator according to the present invention is a wind power generator including a plurality of blades, and at least one of the blades is provided with any one of the airflow generating devices described above.

[0013] Furthermore, the wind power generator of the present invention is a wind power generator having a plurality of blades, in which an airflow generating device as described above is provided on at least one of the blades, and the blade on which the airflow generating device is provided has a sensor that measures the airflow on the surface side of the base of the airflow generating device, and the control unit controls the drive unit based on the measurement results of the sensor. [Effects of the Invention]

[0014] The airflow generating device according to the present invention has the advantage of independently generating an airflow and being easy to install. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view of an airflow generation device according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 3] FIG. 3 is a plan view of the airflow generating device. [Figure 4] FIG. 4 is a schematic diagram of a wind power generator in which an airflow generation device according to an embodiment is installed. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments described below. In addition, in the description of the drawings, the same or corresponding elements are appropriately designated by the same reference numerals. Furthermore, it should be noted that the drawings are schematic, and the dimensional relationships between the elements may differ from the actual ones. There may also be parts in which the dimensional relationships and ratios between the elements differ from one another.

[0017] Additionally, in the drawings, an orthogonal coordinate system of X, Y, and Z axes is shown as appropriate, and directions are explained using this. In the space shown in the orthogonal coordinate system, the direction in which the X component increases is called the +X direction, and the direction in which the X component decreases is called the -X direction. Similarly, the Y and Z components are defined as the +Y direction, -Y direction, +Z direction, and -Z direction. For ease of explanation, the +Z direction is sometimes referred to as the upward direction and the -Z direction as the downward direction, and the Z axis direction may also be referred to as the up-down direction.

[0018] [Embodiment] Fig. 1 is a perspective view of an airflow generation device 1 according to an embodiment of the present invention, and Fig. 2 is a cross-sectional view taken along line AA in Fig. 1. Fig. 3 is a plan view of the airflow generation device 1. The airflow generation device 1 includes a first electrode 11, a second electrode 12, a dielectric layer 13, and a base 14. The airflow generation device 1 also includes a control unit 15, a drive unit 16, a charging unit 17, a secondary battery 18, a sensor 19, and a solar cell 20.

[0019] The dielectric layer 13 is made of a dielectric material and has a rectangular shape. The dielectric layer 13 is made of a resin such as silicone resin (silicon rubber), polyimide resin, epoxy resin, or fluororesin, and is flexible. The first electrode 11 and the second electrode 12 are titanium electrodes formed by coating titanium with platinum, and are formed into a rectangular shape. The first electrode 11 is disposed on the front surface (surface on the +Z direction side) of the dielectric layer 13, and the second electrode 12 is disposed on the back surface (surface on the -Z direction side) of the dielectric layer 13 so as not to overlap with the first electrode 11 when viewed from the +Z direction.

[0020] The base 14 is made of, for example, silicone resin and is flexible. The material of the base 14 is not limited to silicone resin, and other insulating and flexible resin materials may be used. The base 14 covers the dielectric layer 13, control unit 15, drive unit 16, charging unit 17, and secondary battery 18 on the +Z direction side, and the surface on the -Z direction side is flat. The +Y direction end and the -Y direction end of the base 14 are chamfered, and the upper side is curved.

[0021] The secondary battery 18 is, for example, a thin lithium-ion battery that can be charged and discharged. The secondary battery 18 is connected to the driving unit 16 and supplies the driving unit 16 with power for generating the plasma airflow. The secondary battery 18 is disposed on the back surface side of the dielectric layer 13, facing the first electrode 11 with the dielectric layer 13 in between, and disposed so as to be contained within the area of the first electrode 11 when viewed from the +Z direction.

[0022] The solar cell 20 is disposed on the upper surface of the end portion on the +Y direction side of the base 14. The solar cell 20 is, for example, a lightweight and thin perovskite solar cell. Because the perovskite solar cell is in the form of a film and is flexible, it can be disposed along the chamfered curved surface of the base 14. The solar cell 20 receives light energy to generate electricity and supplies the generated electricity to the charging unit 17. Note that the solar cell 20 is not limited to a perovskite solar cell and may be, for example, an organic thin-film solar cell. The solar cell 20 may also be disposed on the upper surface of the chamfered end portion on the -Y direction side of the base 14.

[0023] The charging unit 17 is connected to the solar cell 20 and the secondary battery 18. The charging unit 17 charges the secondary battery 18 with power supplied from the solar cell 20. The charging unit 17 is disposed on the back surface side of the dielectric layer 13, facing the first electrode 11 across the dielectric layer 13, and disposed so as to be contained within the area of the first electrode 11 when viewed from the +Z direction. The driving unit 16 is connected to the first electrode 11, the second electrode 12, the control unit 15, and the secondary battery 18. The driving unit 16 has an inverter that converts DC voltage to AC voltage and a boost circuit that boosts the AC voltage. The driving unit 16 generates an AC voltage of 1 to 20 kHz from the DC voltage applied from the secondary battery 18 and boosts the generated AC voltage to several kV. The driving unit 16 applies the boosted high-frequency AC voltage between the first electrode 11 and the second electrode 12. The driving unit 16 is arranged on the back side of the dielectric layer 13, facing the first electrode 11 across the dielectric layer 13, and is arranged so as to fit within the area of the first electrode 11 when viewed from the +Z direction.

[0024] The sensor 19 includes a MEMS (Micro Electro Mechanical Systems) pressure sensor that measures the pressure on the surface of the airflow generation device 1. The sensor 19 is connected to the control unit 15, and the measurement results of the sensor 19 are sent to the control unit 15. The sensor 19 is an example of a sensor that measures the airflow on the surface of the base 14.

[0025] The control unit 15 has a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and an interface. The ROM is composed of a non-volatile semiconductor memory or the like and stores programs executed by the CPU. The RAM is composed of a semiconductor memory or the like and stores information used when the CPU executes the programs. The interface outputs a signal to control the drive unit 16 in response to an instruction from the CPU. The interface also acquires measurement results from the sensor 19. The control unit 15 realizes the function of generating an airflow on the surface of the dielectric layer 13 on the +Z direction side by having the CPU read and execute a program. The control unit 15 is disposed on the back side of the dielectric layer 13, facing the first electrode 11 across the dielectric layer 13, and disposed so as to be within the area of the first electrode 11 when viewed from the +Z direction.

[0026] 4 is a schematic diagram of a wind power generator 2 on which the airflow generation device 1 is installed. The airflow generation device 1 is attached to the surface of a blade 2a of the wind power generator 2 with an adhesive, for example.

[0027] Control unit 15 acquires the measurement result of sensor 19. For example, when the measurement result of the pressure sensor is equal to or less than a predetermined threshold, control unit 15 controls drive unit 16 so that an AC voltage is applied to first electrode 11 and second electrode 12.

[0028] When an AC voltage is applied between the first electrode 11 and the second electrode 12 from the driving unit 16 under the control of the control unit 15, a dielectric barrier discharge occurs in the area between the first electrode 11 and the dielectric layer 13, generating plasma, and inducing a gas flow (plasma-induced flow) on the surface of the dielectric layer 13 in the direction of the arrow shown in Fig. 2. By inducing a gas flow on the surface of the dielectric layer 13, it is possible to suppress separated flow on the surface of the blade 2a.

[0029] The control unit 15 may also perform burst control, which alternates between a state in which AC voltage is applied and a state in which AC voltage is not applied. This burst control is a control method described, for example, in "Reducing Drive Time and Improving Aerodynamic Performance by Intermittent Burst Drive of Plasma Actuators, Fluid Mechanics Conference / Aerospace Numerical Simulation Technology Symposium 2020 Online Proceedings." This induces intermittent gas flow on the surface of the dielectric layer 13.

[0030] According to this embodiment, the airflow generating device 1 is disposed on the blade 2a of the wind power generator 2 without processing the blade 2a, thereby suppressing separation flow on the surface of the blade 2a. Furthermore, according to this embodiment, the voltage for generating a plasma-induced flow can be generated by the secondary battery 18 and drive unit 16 built into the airflow generating device 1. This allows the airflow generating device 1 to generate a plasma-induced flow by itself without requiring power supply via a cable from an external commercial power source. Furthermore, in this embodiment, the base 14 is flexible, allowing the airflow generating device 1 to be easily installed even on a curved surface. Furthermore, according to this embodiment, the secondary battery 18, charging unit 17, drive unit 16, and control unit 15 are contained within the area of the first electrode 11 when viewed from the +Z direction, thereby reducing the area when viewed from the +Z direction. Furthermore, according to this embodiment, the secondary battery 18, charging unit 17, driving unit 16, and control unit 15 are housed on the back side of the dielectric layer 13, and the surface of the dielectric layer 13 is flat and without irregularities on the -Y direction side from the first electrode 11, which makes it possible to prevent disturbances from occurring in the generated plasma-induced flow.

[0031] [Variations] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be implemented in various other forms. For example, the above-described embodiments may be modified as follows to implement the present invention. The above-described embodiments and the following modifications may be combined with each other. The present invention also includes configurations in which the components of the above-described embodiments and modifications are appropriately combined. Furthermore, further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspects of the present invention are not limited to the above-described embodiments and modifications, and various modifications are possible.

[0032] The solar cell 20 may be disposed on the blade 2a of the wind power generator 2 instead of the base 14. Furthermore, if the sensor 19 is not integrated into the airflow generating device 1, at least one sensor 19 is disposed on the blade surface of the same blade 2a on which the airflow generating device 1 is installed. However, it is more desirable to dispose multiple sensors in the chord length direction starting from the leading edge of the blade 2a.

[0033] The location of the airflow generation device 1 is not limited to the wind power generator 2, and it may be placed in, for example, an automobile or train carriage. The airflow generation device 1 may also be placed on the wall surface of a building.

[0034] In the above-described embodiment, the airflow generating device 1 generates a dielectric barrier discharge by applying an AC voltage between the first electrode 11 and the second electrode 12, thereby inducing a plasma-induced flow. However, a dielectric barrier discharge may also be generated by applying a DC pulse voltage to electrodes arranged on the front and back surfaces of the dielectric to induce a plasma-induced flow. This driving method is, for example, the driving method described in Shintaro Sato and Naofumi Onishi, "Low-Voltage Driven Plasma Actuator," Nagare, Japan Society of Fluid Mechanics, August 2020, Vol. 39, No. 4, pp. 214-221. Furthermore, compared to a method in which a plasma-induced flow is induced using an AC voltage, this method does not require an inverter, thereby simplifying the circuit configuration.

[0035] In the above-described embodiment, the control unit 15, the drive unit 16, the charging unit 17, and the secondary battery 18 are arranged so as to be contained within the area of the first electrode 11 when viewed from the +Z direction, but they may also be arranged outside the area of the first electrode 11 when viewed from the +Z direction as long as they are on the back side of the dielectric layer 13.

[0036] In the present invention, the sensor 19 may include a wind speed sensor and a wind direction sensor, and the control unit 15 may control the drive unit 16 in accordance with the measurement results of these sensors to control the generation of a plasma-induced flow. Furthermore, the control unit 15 may change the frequency of the AC voltage applied between the first electrode 11 and the second electrode 12 or the cycle of burst control based on the measurement results of the sensor 19 to suppress the generation of a separated flow. [Explanation of symbols]

[0037] 1. Airflow generator 2. Wind turbines 11 1st electrode 12 2nd electrode 13 Dielectric layer 14 Base 15 Control Unit 16 Drive unit 17 Live parts 18 Secondary battery 19 Sensors 20 Solar Cells

Claims

1. a dielectric layer; a first electrode disposed on a surface of the dielectric layer; a second electrode disposed on a rear surface of the dielectric layer; a secondary battery for supplying power; a charging unit that charges the secondary battery; a drive unit that receives power supplied from the secondary battery and applies a voltage between the first electrode and the second electrode; a control unit that controls application of a voltage from the drive unit to between the first electrode and the second electrode; a base covering the back surface side of the dielectric layer; and The airflow generating device includes the secondary battery, the charging unit, the driving unit, and the control unit disposed between the rear surface of the dielectric layer and the base.

2. The dielectric layer and the base are flexible. The airflow generating device according to claim 1 .

3. The base portion is chamfered on the upstream side and downstream side of the airflow generated by applying a voltage between the first electrode and the second electrode. The airflow generating device according to claim 1 .

4. A solar cell that supplies power to the charging unit is disposed on the surface of the base. The airflow generating device according to claim 1 .

5. a sensor for measuring airflow on the surface side of the base; The control unit controls the drive unit based on the measurement result of the sensor. The airflow generating device according to claim 1 .

6. A wind power generator having a plurality of blades, wherein the airflow generating device according to any one of claims 1 to 5 is provided on at least one of the blades.

7. A wind power generator having a plurality of blades, wherein an airflow generating device according to any one of claims 1 to 4 is provided on at least one of the blades, and the blade on which the airflow generating device is provided has a sensor that measures the airflow on the surface side of the base of the airflow generating device, and the control unit controls the drive unit based on the measurement results of the sensor.

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