JP6570907B2 - Airflow generator and wind power generation system - Google Patents

Description

  Embodiments described herein relate generally to an airflow generation device and a wind power generation system.

  The wind power generation system generates power using wind energy that is renewable energy. In the wind power generation system, when the wind speed and direction change suddenly, the speed triangle around the wind turbine blade is greatly deviated from the rated point, so that the separation flow may occur in a wide range. When the wind speed or direction fluctuates suddenly, it is not easy to sufficiently cope with the adjustment of the yaw angle and the pitch angle. As a result, in a wind power generation system, it is difficult to stably maintain the power generation output, and it may not be easy to increase efficiency. In particular, in mountainous weather areas such as Japan, wind speed and wind direction change greatly, so that it is difficult to maintain power generation output stably and to increase efficiency. In addition, when a wind power generation system is installed near a private house, noise generation may be a problem.

  For the above countermeasure, it has been proposed to generate an airflow on the surface of the wind turbine blade using an airflow generator. The airflow generation device has a main body portion in which a pair of electrodes is provided via a dielectric, and the main body portion is installed on the surface of the wind turbine blade. And an airflow generator generates an airflow, when a voltage application part (discharge power supply) applies a voltage between the pair of electrodes, and produces | generates a plasma. For example, the pulse modulation frequency is set according to the rotation speed of the wind turbine blade detected by the rotation speed detection unit (rotation speed sensor), and the high-frequency voltage pulse-modulated by the set pulse modulation frequency is set between the pair of electrodes. Apply between. By generating an air flow using the air flow generation device in this way, the flow of the fluid can be controlled on the surface of the wind turbine blade, and the generation of the separation flow can be suppressed. As a result, the lift of the wind turbine blade is increased, and the power generation efficiency can be improved along with the stabilization of power generation. Moreover, the generation of noise can be suppressed.

  In a wind power generation system, for example, a voltage is applied from a stationary body to a rotating body via a slip ring.

JP 2008-25434 A JP 2012-255432 A

  In a wind power generation system, in consideration of efficiency and safety, a voltage application unit (discharge power source) is used for wind turbine blades and the like so as not to supply a high voltage to the main body of the airflow generator via a slip ring. Mounted on a rotating body. In this case, the rotational speed data detected by the rotational speed detection unit (rotational speed sensor) installed on a stationary body such as a nacelle is sent to a voltage application unit installed on the rotational body via a slip ring. It is done. For this reason, malfunction may occur due to noise caused by the slip ring. In addition, since the number of poles of the slip ring is increased, it may be difficult to install the airflow generation device particularly in the existing wind power generation system.

  Therefore, the problem to be solved by the present invention is to suppress an increase in the number of poles of the slip ring, and to effectively prevent malfunction due to noise caused by the slip ring, It is to provide a power generation system.

The airflow generation device of the embodiment includes a main body, a rotation speed detection unit, and a voltage application unit. The main body is provided with a first electrode and a second electrode on a base made of a dielectric, and is installed on a rotating body. The rotation speed detection unit detects the rotation speed of the rotating body. The voltage application unit generates an air flow by applying a voltage between the first electrode and the second electrode based on the number of rotations detected by the rotation number detection unit. Here, the voltage application unit and the rotation speed detection unit are installed inside the rotating body.

1 is a perspective view schematically showing an overall configuration of a wind power generation system according to an embodiment. In the wind power generation system concerning an embodiment, it is a figure showing typically an air current generating device. In the wind power generation system concerning an embodiment, it is a figure showing typically an air current generating device. It is a figure which shows a mode that the structural member of the airflow generation apparatus was arrange | positioned in the wind power generation system which concerns on embodiment. In the airflow generation device of the wind power generation system according to the embodiment, the waveform of the voltage applied by the voltage application unit is illustrated. In an airflow generator of a wind power generation system concerning an embodiment, it is a figure showing data when an acceleration sensor which constitutes a number-of-rotations detection part detects acceleration. It is a block diagram which shows typically the principal part of a voltage application part and a rotation speed detection part in the modification of embodiment.

  Embodiments will be described with reference to the drawings.

[Configuration of wind power generation system 1]
FIG. 1 is a perspective view schematically showing the overall configuration of the wind power generation system according to the embodiment.

  The wind power generation system 1 is, for example, an upwind type propeller windmill, and includes a tower 2, a nacelle 3, a rotor 4, and a wind direction wind speed measuring unit 5 as shown in FIG. 1.

  In the wind power generation system 1, the tower 2 extends along the vertical direction, and a lower end is fixed to a base (not shown) embedded in the ground.

  In the wind power generation system 1, the nacelle 3 is installed at the upper end of the tower 2. The nacelle 3 is supported at the upper end of the tower 2 so as to be rotatable about the vertical direction in order to adjust the yaw angle. Although not shown, a speed increaser and a generator are accommodated in the nacelle 3.

  In the wind power generation system 1, the rotor 4 is rotatably supported at one side end of the nacelle 3, and, for example, rotates in the rotation direction R with the horizontal direction as a rotation axis. The rotor 4 is connected to a rotating shaft of a speed increaser accommodated in the nacelle 3, and a power generator is driven through the speed increaser to generate power. Here, the rotor 4 includes a hub 41 and a plurality of wind turbine blades 42 (blades).

  In the rotor 4, the hub 41 includes a tip cover having a semi-ellipsoidal outer shape, and the tip cover is formed so that the outer diameter of the outer peripheral surface increases in the horizontal direction from the windward to the leeward. Yes.

  In the rotor 4, each of the plurality of wind turbine blades 42 extends in the radial direction around the hub 41, and is arranged so as to be arranged at equal intervals in the rotation direction R. For example, three wind turbine blades 42 are provided, and one end of each wind turbine blade 42 is rotatably supported by the hub 41 for adjusting the pitch angle.

  In each of the plurality of wind turbine blades 42, as shown in FIG. 1, a plurality of main body portions 61 of an airflow generation device 6 described later are installed so as to be aligned in the blade span direction. Details of the airflow generation device 6 will be described later.

  In the wind power generation system 1, the wind direction wind speed measurement unit 5 is attached to the upper surface of the nacelle 3 in the lee of the wind turbine blades 42. The wind direction and wind speed measurement unit 5 measures the wind speed and the wind direction, and outputs the measurement data to a control unit (not shown). Here, the control unit is configured such that the arithmetic unit performs arithmetic processing using a program stored in the memory device, and the yaw angle and the pitch angle according to the measurement data input as described above. Adjustments are made.

[Configuration of Airflow Generator 6]
2 and 3 are diagrams schematically showing the airflow generation device 6 in the wind power generation system 1 according to the embodiment. In FIG. 2, the main body 61 of the airflow generation device 6 is shown in cross section. In FIG. 3, the upper surface of the main body 61 of the airflow generation device 6 is shown. In FIG. 2, the cross section of the XX portion in FIG. 3 is shown. Moreover, in FIG. 3, the outline of the member installed inside among the members which comprise the main-body part 61 is shown with the broken line.

  Moreover, FIG. 4 is a figure which shows a mode that the structural member of the airflow generation apparatus 6 is arrange | positioned in the wind power generation system 1 which concerns on embodiment. 4, the principal part is shown about the side surface of the rotor 4 (refer FIG. 1). Moreover, in FIG. 4, the outline of the member installed in the inside is shown with the broken line.

  As shown in FIGS. 2, 3, and 4, the airflow generation device 6 includes a main body 61, a voltage application unit 62, and a rotation speed detection unit 64.

  Each part which comprises the airflow generation apparatus 6 is demonstrated sequentially.

(Main body 61)
In the airflow generation device 6, the main body 61 includes a base 611, a first electrode 621, and a second electrode 622 as shown in FIGS. 2 and 3.

  Of the main body 61, the base 611 is made of an insulating material (dielectric). For example, the base 611 is formed using a resin such as a silicone resin (silicon rubber), a polyimide resin, an epoxy resin, or a fluororesin, and is flexible.

  In the main body 61, the first electrode 621 is a plate-like body and is formed of a conductive material such as a metal material. As shown in FIG. 2, the first electrode 621 is a surface electrode provided on the surface (upper surface) of the base 611, and extends linearly as shown in FIG.

  In the main body 61, the second electrode 622 is a plate-like body like the first electrode 621, and is formed of a conductive material such as a metal material. As shown in FIG. 2, the second electrode 622 is an internal electrode and is provided inside the base body 611, unlike the first electrode 621. As shown in FIG. 3, the second electrode 622 extends linearly in the same direction (vertical direction in FIG. 3) as the extending direction (first direction, longitudinal direction) in which the first electrode 621 extends. doing. Here, the second electrode 622 is arranged so as to be aligned with the first electrode 621 in a direction (second direction) (lateral direction in FIG. 3) orthogonal to the extending direction (first direction) of the first electrode 621. Has been.

  The main body 61 is formed by various processes such as a press process and an extrusion process.

  As shown in FIG. 4, the main body 61 is installed on a wind turbine blade 42 that is a rotating body. Here, the main body 61 is bonded to the wind turbine blade 42 such that the surface (lower surface) opposite to the surface (upper surface) on which the first electrode 621 is provided is in close contact with the surface of the wind turbine blade 42 (see FIG. 2). For example, the main body 61 is configured such that the first electrode 621 and the second electrode 622 are sequentially arranged from the front edge toward the rear edge on the front edge side portion of the surface (upper surface) on the blade back side of the wind turbine blade 42. Installed. The main body 61 is installed so that the extending direction (first direction) of the first electrode 621 and the second electrode 622 is along the blade span (blade width) direction.

(Voltage application unit 62)
In the airflow generation device 6, the voltage application unit 62 (discharge power source) is electrically connected to the main body unit 61 via the connection unit C <b> 10 as shown in FIGS. 2 and 3. Here, the connection part C10 includes a pair of connection wirings C11 and C12, and electrically connects each of the first electrode 621 and the second electrode 622 to the voltage application part 62. Specifically, one end of the connection line C <b> 11 in the connection part C <b> 10 is electrically connected to the first electrode 621, and the other end is electrically connected to the voltage application part 62. Further, in the connection part C <b> 10, one end of the other connection wiring C <b> 12 is electrically connected to the second electrode 622, and the other end is electrically connected to the voltage application part 62.

  As shown in FIG. 4, the voltage application unit 62 is installed on the wind turbine blade 42 that is a rotating body. In this embodiment, the voltage application part 62 is installed in the blade root side part in the inside of the windmill blade 42, for example. Although not shown, the voltage application unit 62 applies a voltage independently to each of the plurality of main body units 61 (see FIGS. 1 and 4) installed on one wind turbine blade 42. Several are installed. The plurality of voltage application units 62 are arranged so that the overall center of gravity of the plurality of voltage application units 62 installed on each of the plurality of wind turbine blades 42 coincides with the rotation axis of the rotor 4 (see FIG. 1). It is preferable.

  The voltage application unit 62 applies a voltage between the first electrode 621 and the second electrode 622 provided in the main body unit 61 via the connection unit C10. In the present embodiment, the voltage application unit 62 applies a voltage based on the rotational speed detected by the rotational speed detection unit 64.

  Specifically, for example, the voltage application unit 62 is supplied with a DC voltage converted from an AC voltage having a commercial frequency by an AC / DC converter from a stationary body such as the nacelle 3 via a slip ring. In the voltage application unit 62, after the high frequency generator (inverter) generates a high frequency (for example, 1 to 20 kHz) AC voltage from the DC voltage, the transformer boosts the high frequency AC voltage (for example, several kV). ).

  In the voltage application unit 62, the pulse modulator modulates the boosted high-frequency AC voltage with a low-frequency pulse modulation wave. Here, in the voltage application unit 62, first, the computing unit sets the pulse modulation frequency F of the pulse modulation wave based on the rotation speed n (rpm) detected by the rotation speed detection unit 64.

  Specifically, as shown in the following formula (A), together with the rotation speed n (rpm) detected by the rotation speed detection unit 64, a preset Strouhal number St and the code length Cn (m of the wind turbine blade 42) ), The pulse modulation frequency F is set by performing arithmetic processing using the rotation radius Rn of the wind turbine blade 42. Here, in the above-described formula (A), for Cn, a portion where the center of each of the plurality of main body portions 61 (the center in the extending direction of the first electrode 621 and the second electrode 622) is located in the wind turbine blade 42. Rn is the distance between the center of each of the plurality of main body portions 61 and the rotation axis AX in the span direction of the wind turbine blade 42, and the pulse modulation frequency F of each of the plurality of main body portions 61 is determined. Set up.

  F = (2πn / 60) × St × Cn × Rn (A)

  Then, a high-frequency AC voltage is pulse-modulated with the pulse modulation wave having the set pulse modulation frequency F. Thereafter, the voltage application unit 62 applies the pulse-modulated high-frequency AC voltage between the first electrode 621 and the second electrode 622.

  FIG. 5 illustrates the waveform of the voltage applied by the voltage application unit 62 in the airflow generation device 6 of the wind power generation system 1 according to the embodiment. In FIG. 5, the horizontal axis is time, and the vertical axis is voltage value.

  As illustrated in FIG. 5, the voltage application unit 62 applies a high-frequency voltage (alternating voltage) between the first electrode 621 and the second electrode 622 at a preset frequency (basic frequency). The high-frequency voltage is pulse-modulated with a pulse-modulated wave (not shown) having a frequency lower than that of the high-frequency voltage, and is applied in each period (T1, T2,... = 1 / F) of the pulse-modulated wave. The

  Specifically, first, in the first cycle T1, application of voltage starts at the first time point t1. Then, a voltage is applied at a preset frequency (basic frequency) at time t12 (first on-time) between the first time point t1 and the second time point t2, and airflow is generated. That is, a voltage that changes between positive polarity and negative polarity according to time is periodically and repeatedly applied. After that, at time t23 (first off time) between the second time point t2 and the third time point t3, the application of voltage is stopped and the generation of airflow is stopped (T1 = t12 + t23).

  In the second period T2 (= T1), a high-frequency voltage is applied as in the case of the first period T1. That is, application of a voltage is started at the third time point t3. Then, at the time t34 (second on-time) between the third time point t3 and the fourth time point t4, as in the first cycle T1, a high-frequency voltage at a preset frequency (fundamental frequency). Is applied and airflow is generated. The time t34 (second on-time) for generating airflow in the second period T2 is the same as the time t12 (first on-time) for generating airflow in the first period T1, for example. Thereafter, at time t45 (second off time) between the fourth time point t4 and the fifth time point t5, the application of the high-frequency voltage is stopped and the generation of the air current is stopped (T2 = t34 + t45). .

  Although illustration is omitted, in the period after the second period T2 (after the third period), the voltage is applied as in the case of the first period T1 and the second period T2. Is called.

  By applying the voltage, plasma due to the barrier discharge is generated on the surface (upper surface) of the main body 61, and an air flow (plasma induced flow) is induced. The airflow is induced to flow from the first electrode 621 side toward the second electrode 622 side, and the generation of the separation flow is suppressed.

(Rotation speed detector 64)
In the air flow generation device 6, the rotation speed detection unit 64 (rotation speed sensor) is electrically connected to the voltage application unit 62 via a connection unit C20 including a signal line, as shown in FIGS. Yes. Although not shown in the drawings, the rotation speed detection unit 64 applies a plurality of voltages applied corresponding to each of the plurality of main body units 61 installed on one wind turbine blade 42 (see FIGS. 1 and 4). The unit 62 is electrically connected. Further, the rotation speed detection unit 64 is supplied with power from, for example, the voltage application unit 62.

  As shown in FIG. 4, the rotation speed detection unit 64 is installed on the wind turbine blade 42 that is a rotating body. In the present embodiment, the rotational speed detection unit 64 is installed in the blade root side portion of the wind turbine blade 42, for example, in the same manner as the voltage application unit 62.

  The rotation speed detection unit 64 detects the rotation speed of the rotor 4 including the wind turbine blades 42 and outputs a data signal of the detected rotation speed to the voltage application unit 62 in real time via the connection unit C20.

  In the present embodiment, the rotation speed detection unit 64 includes, for example, an acceleration sensor formed using a semiconductor. In the rotation speed detection unit 64, the acceleration sensor detects acceleration on an axis along the vertical direction. And the rotation speed detection part 64 calculates | requires the rotation speed of the rotor 4 when a calculator performs a calculation process about the acceleration detected by the acceleration sensor. Since the acceleration sensor is small, it is easy to install.

  FIG. 6 is a diagram illustrating data when the acceleration sensor included in the rotation speed detection unit 64 detects acceleration in the airflow generation device 6 of the wind power generation system 1 according to the embodiment. In FIG. 6, the horizontal axis is time t, and the vertical axis is acceleration a. FIG. 6 shows a state when the rotor 4 makes one rotation.

  As shown in FIG. 6, when the rotor 4 makes one revolution, the acceleration a changes so as to draw a sine curve according to the time t. For this reason, it can obtain | require by converting the rotation speed per unit time (rpm) from time T10 (namely, period) when it rotates once.

[Action and effect]
As described above, in the present embodiment, the voltage application unit 62 (discharge power source) is installed on the wind turbine blade 42 that is a rotating body. At the same time, the rotational speed detection unit 64 is installed on the wind turbine blade 42 which is a rotating body. For this reason, in the present embodiment, the rotational speed data detected by the rotational speed detection unit 64 installed in the rotating body is sent to the voltage application unit 62 installed in the rotating body without a slip ring. It is done.

  Therefore, in this embodiment, it is possible to prevent a malfunction from occurring due to noise caused by the slip ring. Moreover, in this embodiment, it can prevent that the pole number of a slip ring increases. As a result, it becomes easy to install the airflow generation device 6 in the existing wind power generation system 1.

[Modification]
In the above-described embodiment, the case where both the voltage application unit 62 (discharge power source) and the rotation speed detection unit 64 are installed on the wind turbine blades 42 of the rotor 4 has been described. For example, you may install in the hub 41 of the rotor 4. FIG.

  In the above embodiment, the case where the DC voltage is supplied from the stationary body side to the voltage applying unit 62 via the slip ring has been described, but the present invention is not limited to this. The DC voltage may be supplied to the voltage application unit 62 by wireless power feeding.

  In the above embodiment, the case where the rotational speed detection unit 64 detects the rotational speed using the acceleration sensor has been described, but the present invention is not limited thereto. For example, the rotation speed detection unit 64 may be configured to detect the rotation speed using an optical fiber sensor. That is, the rotational speed may be detected based on the fact that the characteristics of light passing through the optical fiber sensor fluctuate due to the rotation. In addition, the rotation speed detection unit 64 may be configured to detect the rotation speed by various methods.

  In the above-described embodiment, the rotational speed detection unit 64 is installed in the blade root side portion inside the wind turbine blade 42, similarly to the voltage application unit 62. And in said embodiment, the rotation speed detection part 64 detects the rotation speed of the rotor 4 containing the windmill blade 42, and the voltage application part detects the data signal of the detected rotation speed via the connection part C20 in real time. To 62. However, the configuration is not limited to this.

  FIG. 7 is a block diagram schematically showing the main parts of the voltage application unit 62 and the rotation speed detection unit 64 in a modification of the embodiment.

  As shown in FIG. 7, the voltage application unit 62 (discharge power source) includes a housing 620, and the constituent members such as the high-frequency generator 621 are accommodated in the housing 620, and the configuration of the voltage application unit 62 is included. You may comprise so that the rotation speed detection part 64 which is not a member may be accommodated further. Of the constituent members of the voltage application unit 62, the transformer 622 is preferably installed outside the housing 620 because it may be a noise source. The casing 620 of the voltage application unit 62 is preferably made of metal. Thereby, when transmitting a signal from the rotation speed detection part 64 to the voltage application part 62, it can avoid that the connection part C20 receives an electrical noise and a signal changes.

  In the above embodiment, the connection unit C20 is used to transmit a signal from the rotation speed detection unit 64 to the voltage application unit 62. However, the present invention is not limited to this. You may comprise so that transmission / reception of the signal between the rotation speed detection part 64 and the voltage application part 62 may be performed by radio. That is, the above signal transmission may be performed wirelessly. Accordingly, it is possible to avoid the connection portion C20 receiving electrical noise and changing the signal during signal transmission from the rotation speed detection unit 64 to the voltage application unit 62.

  According to at least one embodiment described above, the voltage application unit and the rotation speed detection unit are installed in the rotating body, thereby suppressing an increase in the number of poles of the slip ring and causing malfunction due to the occurrence of noise caused by the slip ring. This can be effectively prevented.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Wind power generation system, 2 ... Tower, 3 ... Nacelle, 4 ... Rotor, 5 ... Wind direction wind speed measurement part, 6 ... Airflow generator, 41 ... Hub, 42 ... Windmill blade, 61 ... Main-body part, 62 ... Voltage application part , 64... Rotational speed detector, 611... Base, 621... First electrode, 622.

Claims (7)

A first body and a second electrode are provided on a base formed of a dielectric, and a main body installed on the rotating body;
A rotational speed detector for detecting the rotational speed of the rotating body;
A voltage application unit that generates an air flow by applying a voltage between the first electrode and the second electrode based on the number of rotations detected by the rotation number detection unit;
The voltage application unit and the rotation speed detection unit are installed inside the rotating body,
Airflow generator. The rotational speed detection unit includes an acceleration sensor.
The airflow generation device according to claim 1. The voltage application unit applies a voltage pulse-modulated with a pulse modulation frequency set according to the rotation speed detected by the rotation speed detection unit, between the first electrode and the second electrode.
The airflow generation device according to claim 1 or 2. The rotating body has a wind turbine blade,
Each of the main body, the rotation speed detection unit, and the voltage application unit is installed on the wind turbine blade.
The airflow generation device according to any one of claims 1 to 3.   The airflow generation device according to claim 1, wherein the rotation speed detection unit is installed inside a casing constituting the voltage application unit.   The airflow generation device according to claim 1, wherein a signal is transmitted and received between the rotation speed detection unit and the voltage application unit wirelessly. A wind power generation system comprising: a rotating body on which a windmill blade is installed; and an airflow generation device that generates an airflow on a surface of the windmill blade,
The airflow generator is
A base body formed of an insulating material is provided with a first electrode and a second electrode, and a main body portion installed on the surface of the wind turbine blade,
A rotational speed detector for detecting the rotational speed of the rotating body;
A voltage application unit that generates an air flow by applying a voltage between the first electrode and the second electrode based on the number of rotations detected by the rotation number detection unit;
The voltage application unit and the rotation speed detection unit are installed inside the rotating body,
Wind power generation system.

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