JP2011220218A - Windmill and its control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a windmill which can reduce effect of low frequency sound, and a control method of the same.SOLUTION: The windmill 1 is a horizontal axis windmill supported by a nacelle, which is provided on the top of a tower vertically arranged on the ground. The windmill 1 has blades and receives wind to rotate. The windmill 1 includes: a rotation speed detector 2 detecting rotation speed of the windmill 1; and a rotation speed control device 3 controlling the rotation speed of the windmill 1. The rotation speed control device 3 controls the rotation speed of the windmill 1, when the rotation speed of the windmill 1 detected by the rotation speed detector 2 continues at a fixed time or more within a predetermined range.

Description

  The present invention relates to a windmill having blades and rotating by receiving wind and a control method thereof.

In recent years, the use of natural energy such as wind power has attracted attention from the viewpoint of CO ₂ reduction.

  For example, Non-Patent Documents 1 and 2 describe technologies relating to wind power generation. In wind power generation, wind turbine blades are rotated by wind power, and the rotational motion is transmitted to a generator to generate power. That is, wind energy is converted into rotational energy and extracted as electrical energy. A wind power generation system generally has a structure in which a nacelle is installed at the top of a tower, and a horizontal axis wind turbine (a wind turbine whose rotation axis is substantially parallel to the wind direction) is attached to the nacelle. The nacelle stores a speed increaser that speeds up and outputs the rotational speed of the rotating shaft of the windmill, and a generator that is driven by the output of the speed increaser. The speed increaser increases the number of rotations of the wind turbine to the number of rotations of the generator (for example, 1: 100), and a gear box is incorporated.

  In addition, wind turbines of wind power generation systems usually have a variable pitch mechanism that adjusts the pitch angle of the blades, and adjust the pitch angle of the blades according to fluctuations in the wind speed so that they rotate at the rated rotational speed. Pitch control is performed to control the speed.

  Recently, there is a tendency to increase the size of wind turbines in order to reduce power generation costs, and large wind power generation systems with a wind turbine diameter of 80 m or more and an output of 2 MW class have been developed. In the case of a wind turbine of a large wind power generation system, generally, the number of blades is 1 to 3 (mainly 3), and the rated rotational speed is set within a range of about 10 to 60 rpm.

“Wind Power Generation (01-05-01-05)”, [online], Atomic Encyclopedia ATOMICA, [Search on March 31, 2010], Internet <URL: http://www.rist.or.jp/ atomica /> “Subaru wind power generation system SUBARU WIND TURBINE”, [online], Fuji Heavy Industries, Ltd., [March 31, 2010 search], Internet <URL: http://www.subaru-windturbine.jp/windturbine/> “Special issue on low frequency sound problems”, [online], [Search on March 31, 2010], Internet <URL: http://www.soumu.go.jp/kouchoi/substance/chosei/pdf/028/ teisyhaaon.pdf> “Status of standards, etc. related to noise and low-frequency sound generated from wind power generation facilities in foreign countries (provisional version)”, [online], [searched on March 31, 2010], Internet <URL: http: / /www.env.go.jp/press/file_view.php?serial=13184&hou_id=10905>

  By the way, with the spread of wind power generation, the problem of low frequency sound generated from windmills is being taken up (for example, see Non-Patent Documents 3 and 4). Low-frequency sound is sound waves of approximately 100Hz or less (especially, sound waves of 20Hz or less are called ultra-low-frequency sounds). The effects of low-frequency sound include physical effects such as rattling of furniture and headaches. There are human effects such as tinnitus, nausea and sleep disturbance. The basic frequency f of the low frequency sound generated from the windmill is given by f = RZ / 60 (Hz) where R (rpm) and the number of blades are Z (sheets). In particular, in the case of a wind turbine of a large wind power generation system, since the number of blades is small and the rotation speed is low, low frequency sound is generated even during normal operation in the operating wind speed range, and the sound pressure level is also high, It is assumed that the influence of low frequency sound is great.

  However, so far, no effective reduction measures have been found for low-frequency sound generated from windmills.

  The present invention has been made in view of the above circumstances, and one of its purposes is to provide a windmill capable of reducing the influence of low-frequency sound and a control method thereof.

  The inventor considered the influence of low-frequency sound as follows. The wind turbine is designed to rotate at a set rated rotational speed by controlling the rotational speed according to the wind speed. Also, depending on the terrain and time zone, a steady wind may blow. Therefore, low-frequency sound having a substantially constant frequency may be continuously generated from the windmill for a certain period of time. As a result, if the frequency of the low frequency sound matches the natural frequency of the joinery, etc., the rattling of the joinery will continue to occur, or the person will feel uncomfortable by continuing to be exposed to the low frequency sound of a substantially constant frequency. Presumed to feel strong.

  Then, the present inventor has found that when the windmill continues to rotate at a substantially constant rotational speed for a certain period of time, by controlling the rotational speed of the windmill, low frequency sound having a substantially constant frequency is generated over a long period of time. Based on this idea, the present invention has been completed.

  The windmill of the present invention is a windmill that has blades and rotates by receiving wind, and includes a rotational speed detector that detects the rotational speed of the windmill, and a rotational speed control device that controls the rotational speed of the windmill. The rotational speed control device controls the rotational speed of the windmill when the rotational speed of the windmill detected by the rotational speed detector continues within a predetermined range for a predetermined time or more.

  On the other hand, the wind turbine control method of the present invention is a wind turbine control method that has blades and rotates by receiving wind, and when the wind turbine rotates continuously at a rotational speed within a predetermined range for a predetermined time or more, It is characterized by controlling the rotational speed of the windmill.

  According to the wind turbine and the wind turbine control method of the present invention, when the wind turbine continues to rotate at a substantially constant rotational speed for a certain time in the operating wind speed range (between cut-in wind speed and cut-out wind speed), the rotational speed of the wind turbine is positively increased. By performing the control, it is possible to prevent the low frequency sound having a substantially constant frequency from being generated over a long period of time. As a result, the influence of low frequency sound can be reduced.

  In the present invention, the predetermined range can be set as appropriate. For example, the change in rotational speed is set to be less than 10%. For example, when the rotational speed is less than 10%, it is considered that the rotational speed varies and it is determined that the windmill is rotating at a constant rotational speed. And when controlling the rotational speed of a windmill, it controls so that it may change 10% or more from a certain fixed rotational speed before control. In the present invention, the fixed time can be set as appropriate, for example, 10 minutes, preferably 5 minutes.

  As one form of the windmill of the present invention, a variable pitch mechanism for adjusting the pitch angle of the blade is provided, and the rotational speed control device controls the rotational speed of the windmill by adjusting the pitch angle of the blade by the variable pitch mechanism. To do.

  According to this configuration, it is possible to cope with the conventional windmill only by changing the control system without making a particularly large change.

  As one form of the windmill of the present invention, a rotating shaft that rotates in conjunction with the windmill, a rotating body that is supported by the rotating shaft, a coil that generates a rotating magnetic field in accordance with the rotation of the rotating body, and an electric current supplied to the coil And a conductor through which an induced current caused by the magnetic flux of the rotating magnetic field flows. The rotational speed control device controls the rotational speed of the windmill by controlling the current flowing from the power source to the coil and adjusting the torque in the direction to stop the rotation of the rotating body generated by the induced current flowing in the conductor. To do.

  According to this configuration, a rotating magnetic field is generated in the rotating body by the coil, and an induced current caused by the magnetic flux of the rotating magnetic field flows through the conductor. Braking torque). Since the braking torque is proportional to the induced current generated in the conductor, and this induced current is proportional to the change in the magnetic flux of the rotating magnetic field that penetrates the space surrounded by the conductor, the current applied to the coil that generates the rotating magnetic field is adjusted. By doing so, it is possible to adjust the braking torque.

  The windmill and the control method thereof according to the present invention can reduce the influence of low-frequency sound by positively controlling the rotational speed of the windmill when the windmill continues to rotate at a substantially constant rotational speed for a certain period of time.

It is a schematic diagram which shows an example of the windmill which concerns on this invention. It is a block diagram which shows an example of the windmill which concerns on this invention. In the windmill concerning the present invention, it is a flow chart which shows an example of a judgment procedure whether a rotation speed control device controls the rotation speed of a windmill. It is the schematic which shows the 2nd structural example of the specific means which controls the rotational speed of the windmill which concerns on this invention, (A) is the front view seen from the rotating shaft side, (B) is a rotating shaft. It is the side half sectional view cut | disconnected along the axial direction. It is the schematic which shows the 2nd structural example of the specific means which controls the rotational speed of the windmill concerning this invention, and is the principal part expansion perspective view which decomposed | disassembled one part. In the second configuration example of the specific means for controlling the rotational speed of the windmill according to the present invention, the magnetic field (magnetic flux density) T generated between the magnetic projection and the magnetic projection when the rotating body rotates. It is a schematic diagram which shows the time change of. It is the schematic which shows the 2nd structural example of the specific means which controls the rotational speed of the windmill which concerns on this invention, and is a front view which shows one state in which a rotary body is rotating. It is a schematic diagram which shows an example of the electric power generation system using a windmill provided with the 2nd structural example of the specific means which controls the rotational speed of the windmill which concerns on this invention.

  Embodiments of the present invention will be described with reference to the drawings. In the drawings, the same reference numerals indicate the same or corresponding parts.

(Embodiment)
A wind turbine 1 according to the present invention shown in FIG. 1 is a horizontal axis wind turbine in which a nacelle 202 is installed on an upper portion of a tower 201 standing on the ground and supported by the nacelle 202. This windmill 1 has three blades 10, and each blade 10 is radially attached to a hub 12 fixed to the tip of a rotating shaft 11. Further, an anemometer 203 is attached to the nacelle 202.

  As shown in FIG. 2, the windmill 1 includes a rotational speed detector 2 and a rotational speed control device 3.

  The rotational speed detector 2 is a device that detects the rotational speed of the windmill 1. The rotation speed can be obtained by dividing the number of rotations by time. As the rotational speed detector 2, a commercially available rotational speed meter such as a rotary encoder can be used. For example, a rotational speed meter is provided on the rotating shaft 11 that rotates in conjunction with the windmill 1. The rotation speed detector 2 outputs the detected rotation speed of the windmill 1 to the rotation speed control device 3.

  The rotational speed control device 3 is a device that controls the rotational speed of the windmill 1. The rotational speed control device 3 receives the rotational speed of the windmill 1 detected by the rotational speed detector 2. Specific means for controlling the rotational speed of the windmill will be described later.

  The rotational speed control device 3 controls the rotational speed of the windmill 1 when it is determined that the rotational speed of the windmill 1 input from the rotational speed detector 2 continues for a certain period of time within a predetermined range. Here, an example of a procedure for determining whether or not to control the rotational speed of the windmill 1 of the rotational speed control device 3 will be described with reference to FIG.

≪Step S1: Initialization≫
Initialization of the timer t and initialization of the reference rotation speed R ₀ are performed. Here, the rotational speed value input from the rotational speed detector earlier is set to the rotational speed _R0 .

«Step S2: Obtaining rotational speed R _1»
Get the rotational speed of the current input from the rotational speed detector, set this value to the value of the rotational speed R _1.

«Step S3: if the rotational speed R ₁ is within a predetermined range determination»
Rotational speed R ₁ determines whether within a predetermined range. Here, the change in the rotational speed R ₁ with respect to the reference rotational speed R ₀ is set to be less than 10% within a predetermined range. When the rotational speed R ₁ is less than 10% of the reference rotational speed R ₀ , it is considered that the windmill is rotating at a constant rotational speed, and the process proceeds to the next step S4. On the other hand, when the rotation speed R ₁ with respect to the rotational speed R ₀ as a reference is a change in the 10% or more, the process returns to step S1, and initializing a timer t, the value of the rotational speed R ₀ as the reference rotation changing the value of the speed R _1.

≪Step S4: Judgment whether or not it continues to rotate at a constant rotation speed R ₀ for a certain period of time≫
It is determined whether or not the value of timer t has exceeded a preset time T ₀ . If the time T ₀ or more has not elapsed, the process returns to step S2. On the other hand, when the time T ₀ or more has elapsed, it is determined that the windmill continues to rotate at a constant rotation speed for a certain time, and the process proceeds to the next step 5.

≪Step S5: Rotational speed control≫
Control the rotation speed of the windmill. Here, when the rotation speed is controlled, the rotation speed is controlled so that it is changed by 10% or more from the rotation speed R ₀ before the control. After controlling the rotation speed, the process returns to step S1.

  Next, specific means for controlling the rotational speed of the windmill will be described.

(Example 1)
As a first configuration example of specific means for controlling the rotational speed of the windmill, there is a configuration including a variable pitch mechanism for adjusting the pitch angle of the blade. In the case of a wind turbine having a conventional variable pitch mechanism, pitch control is performed so as to keep the rotation speed constant in the operating wind speed range (between cut-in wind speed and cut-out wind speed). In the present invention, when the rotational speed control device 3 (see FIG. 2) determines that the rotational speed of the windmill 1 input from the rotational speed detector 2 continues within a predetermined range for a certain time or more, the rotational speed control device 3 Sends a signal to the variable pitch mechanism to adjust the blade pitch angle. The variable pitch mechanism is incorporated in the hub 12 (see FIG. 1) of the wind turbine 1.

  In the wind turbine provided with the above first configuration example, when controlling the rotational speed, for example, the pitch angle (tilt) of the blade is made small with respect to the wind direction so that the torque in the rotational direction becomes small with respect to the wind speed, The rotation speed can be reduced. If the rotational speed has already been reduced with respect to the wind speed by the rotational speed control device, the blade pitch angle is further reduced to reduce the rotational speed, and the rotational speed of the blade is increased so that the rotational torque increases with respect to the wind speed. The pitch angle (tilt) can be increased with respect to the wind direction to increase the rotation speed. Therefore, the rotational speed of the windmill can be controlled by adjusting the pitch angle of the blades with the above configuration.

(Example 2)
As a second configuration example of the specific means, it is possible to control the rotational speed of the windmill using an induced current. For example, as shown in FIGS. 4 and 5, the rotating body 31, the yoke 32, the coil 33, and the conductor 34 are provided. In FIG. 4, only the conductor is shown in cross section.

  The rotating body 31 is a cylindrical member that is stored in the nacelle on the side opposite to the hub side of the rotating shaft 11 of the windmill and supported by the rotating shaft 11. In this example, the rotating body 31 is supported on the rotating shaft 11 via support members 315 extending radially from the rotating shaft 11. On the outer peripheral surface of the rotator 31, a pair of magnetic projections 311 and 312 that protrude in the centrifugal direction of the rotator 31 and are aligned in the axial direction of the rotator 31 are integrally provided. In addition, a pair of magnetic convex portions 311 and 312 arranged in the axial direction is set as a set, and a plurality (18 sets in this case) of these are arranged in parallel at equal intervals in the circumferential direction. The rotating body 31 is made of a magnetic material including the magnetic convex portions 311, 312. Examples of the magnetic material to be used include iron, nickel, cobalt, silicon steel, permalloy, and ferrite. Here, the windmill rotates counterclockwise when viewed from the hub side, and the rotating body 31 rotates counterclockwise when viewed from the rotating shaft 11 side (the arrow in FIG. 4A indicates the direction of rotation). ).

  The yoke 32 is a cylindrical member disposed on the outer peripheral side of the rotating body 31 with a predetermined distance from the rotating body 31. On the inner peripheral surface of the yoke 32, a pair of magnetic protrusions projecting toward the rotating body 31 and aligned in the axial direction of the rotating body 31 so as to correspond to the magnetic protrusions 311 and 312 provided on the rotating body 11 described above. 321,322 are provided integrally. In this example, a pair of magnetic projections 321 and 322 arranged in the axial direction is set as a set, and a plurality (18 sets in this case) are arranged in parallel in the circumferential direction. Further, the yoke 32 is formed of a magnetic material including the magnetic protrusions 321 and 322, as with the rotating body 31. Here, the yoke 32 is fixed so as not to rotate.

  The coil 33 includes a rotating body 31, a pair of magnetic projections 311, 312, a pair of magnetic projections 321, 322, and a yoke 32 when the pair of magnetic projections 311, 312 and the pair of magnetic projections 321, 322 face each other. It is wound to pass through the enclosed space. In this example, the coil 33 is disposed in an annular space between the rotary body 31 and the yoke 32, and is fixed to the yoke 32 side with a gap from the rotary body 31. The coil 33 is a normal conducting copper coil and is connected to a DC power source (not shown). Here, the direction of the direct current supplied to the coil 33 is the same as the direction of rotation of the rotating body 11 (the arrow in FIG. 5 indicates the direction in which the current flows).

  In this example, the case where the coil 33 is a normal conducting coil has been described as an example, but the coil 33 may be a superconducting coil. When a direct current is applied to a coil to generate a magnetic field, the superconducting coil has zero electrical resistance, and even if a large current is applied, the coil does not substantially generate heat (loss). Therefore, compared with a normal conducting coil, heat generation (loss) of the coil caused by energizing a large current can be suppressed, and a strong magnetic field can be generated without power loss.

  The conductor 34 is an annular member disposed so as to surround the periphery of the magnetic protrusions 321 and 322 provided on the yoke 32 (see FIG. 5). Each conductor 34 is formed of a conductive material, and examples of the conductive material to be used include metals such as aluminum, copper, and iron. In this example, aluminum is used for the conductor 34 to reduce the weight.

  Next, a mechanism for controlling the rotation speed in the wind turbine provided with the above second configuration example will be described.

  When the coil 33 is energized, a magnetic field is generated clockwise in the direction in which the current flows (in the case of FIG. 4B, from the front to the back of the page), and the rotating body 31, the pair of magnetic projections 311, 312, Magnetic flux flows through the magnetic projections 321 and 322 and the yoke 32 to form a magnetic circuit (dotted arrows in FIG. 4B indicate an image of the flow of magnetic flux). Specifically, when the pair of magnetic projections 311, 312 and the pair of magnetic projections 321, 322 face each other, the rotating body 31 → one magnetic projection 311 → one magnetic projection 321 → yoke 32 → the other. The magnetic circuit of the magnetic material projection 322 → the other magnetic material projection 312 → the rotating body 31 is formed. When the rotating body 31 rotates, when the pair of magnetic body convex portions 311, 312 and the pair of magnetic body projecting portions 321, 322 face each other and are close to each other, the magnetic gap in the magnetic circuit is reduced, and the magnetic circuit The magnetic flux that flows through increases. On the other hand, when the pair of magnetic protrusions 311, 312 and the pair of magnetic protrusions 321, 322 are separated from each other, the magnetic gap in the magnetic circuit is increased, and the magnetic flux flowing in the magnetic circuit is reduced. That is, the magnetic flux changes in the circumferential direction on the outer peripheral side of the rotating body 31, and a rotating magnetic field is generated as the rotating body 31 rotates. Accordingly, since the magnetic flux flowing through the yoke 32 changes due to the rotation of the rotating body 31, the magnetic flux penetrating the annular conductor 34 disposed around the magnetic protrusions 321 and 322 changes, and the induced electromotive force ( Counter electromotive force) occurs. As a result, an induced current flows through the conductor 34, and a torque (braking torque) in a direction to stop the rotation of the rotating body 31 is generated by the induced current.

  FIG. 6 is a schematic diagram showing temporal changes in the magnetic field (magnetic flux density) T generated between the magnetic projections 311 and 312 and the magnetic projections 321 and 322 when the rotating body 31 rotates. As shown in FIG. 1A, the magnetic field T is when the magnetic convex portions 311, 312 and the magnetic protruding portions 321 and 322 face each other, and the gap length between the magnetic protruding portion and the magnetic protruding portion is the smallest. Is maximal and maximal. On the other hand, as shown in FIG. 7, due to the rotation of the rotating body 31 (in this case, 10 °), the magnetic projections 311 and 312 are displaced from the magnetic projections 321 and 322, and the magnetic projections-magnetic projections When the gap length between them is the largest, it is minimal and minimal.

  In the wind turbine provided with the above-described second configuration example, when the rotation speed is controlled, the rotation control device controls the current flowing from the power source (not shown) to the coil 33. When the current flowing through the coil 33 is increased, the magnetic flux density of the rotating magnetic field is increased and the magnetic flux penetrating the conductor 34 is increased, so that the induced current flowing through the conductor 34 can be increased. As a result, the braking torque of the rotating body 31 generated by the induced current can be increased, so that the rotational speed can be reduced. On the other hand, if the current flowing through the coil 33 is reduced, the induced current flowing through the conductor 34 can be reduced, and the braking torque of the rotating body 31 generated by the induced current can be reduced, so that the rotational speed can be increased. Therefore, with the above configuration, the rotational speed of the windmill can be controlled by adjusting the braking torque of the rotating body 31 generated by the induced current flowing in the conductor 34. In the wind turbine provided with the second configuration example described above, the rotating body 31, the yoke 32, the coil 33, and the conductor 34 can be stored in the nacelle 202 (see FIG. 1).

  The windmill and the control method thereof according to the present invention described above can reduce the influence of low-frequency sound by controlling the rotational speed of the windmill when the windmill continues to rotate at a substantially constant rotational speed for a certain period of time.

<Heat medium heating device>
In the case of the wind turbine having the above-described second configuration example, when the induced current flows through the conductor 34, the conductor 34 generates heat due to electric resistance. Therefore, a heat medium heating device that heats a heat medium such as water using this heat may be realized.

  For example, as shown in FIG. 4A, it is conceivable to provide a pipe through which the heat medium flows in each conductor 34 so that the heat medium can receive heat from each conductor 34. In this example, each conductor 34 is provided with a through-hole penetrating along the axial direction of the rotating body 31, and passes through the through-holes of the front and rear conductors 34 arranged in the pair of magnetic projections 321 and 322 arranged in the axial direction. As shown, the pipe 35 is inserted. The pipe 35 is made of metal and is thermally connected to the conductor 34. Further, for example, in this example, a heat medium is supplied from one end side of the pipe 35 and discharged from the other end side, or a connection pipe that connects the pipe 35 and another pipe 35 is provided on one end side of the pipe 35. For example, the heat medium can be supplied from the other end side of the pipe 35 and discharged from the other end side of the other pipe 35 through the connecting pipe. That is, in the former case, the flow path is one-way, and in the latter case, the flow path is reciprocal. In the latter case, the heating distance of the heat medium can be increased as compared with the former case.

  In the case of a heat medium heating device, in order to prevent heat from escaping from the conductor 34, the conductor 34 may be covered with a heat insulating material 34i as shown in FIG. 4, for example. As the heat insulating material 34i, for example, rock wool, glass wool, foamed plastic, brick, ceramics, or the like can be used.

<Power generation system>
Furthermore, you may implement | achieve the electric power generation system which utilizes the heat | fever of the heat medium heated with the above-mentioned heat medium heating apparatus for electric power generation. As an example of such a power generation system, as shown in FIG. 8, for example, a wind turbine 1 including the second configuration example described above, a heat accumulator 50, and a power generation unit 60 are provided.

  The windmill 1 has the configuration of the heat medium heating device described above. Parts of the heat medium heating device 30 for heating the heat medium (a part of the rotating shaft 11, the rotating body 31, the yoke 32, the coil 33, the conductor 34, the pipe 35, and the like shown in FIG. 4) are stored in the nacelle 202. . In addition, a heat accumulator 50 and a power generation unit 60 are installed in the lower part (above ground) of the tower 201. Hereinafter, the configuration of the power generation system P shown in FIG. 8 will be described in detail. Here, a case where the heat medium is water will be described as an example.

  A water supply pipe 51 that supplies water to the heat medium heating device 30 and a transport pipe 52 that sends water heated by the heat medium heating device 30 to the heat accumulator 50 are connected to the piping of the heat medium heating device 30. The heat medium heating device 30 heats water flowing through the piping with heat generated by the induction current flowing through the conductor.

  The heat medium heating device 30 heats water to a temperature suitable for power generation (for example, 200 ° C. to 350 ° C.) to generate high-temperature and high-pressure water. The high-temperature and high-pressure water is sent to the heat accumulator 50 through a transport pipe 52 that connects the heat medium heating device 30 and the heat accumulator 50.

  The heat accumulator 50 stores the heat of the high-temperature and high-pressure water sent through the transport pipe 52, and supplies steam necessary for power generation to the power generation unit 60 using a heat exchanger. Note that steam may be generated by the heat medium heating device 30. As the heat accumulator 50, for example, a steam accumulator, a sensible heat type using a molten salt or oil, or a latent heat type heat accumulator using a phase change of a molten salt having a high melting point can be used. Since the latent heat type heat storage method stores heat at the phase change temperature of the heat storage material, the heat storage temperature range is generally narrower than that of the sensible heat type heat storage method, and the heat storage density is high.

  The power generation unit 60 has a structure in which a steam turbine 61 and a generator 62 are combined. The steam turbine 61 is rotated by the steam supplied from the heat accumulator 50, and the generator 62 is driven to generate power.

  The high-temperature high-pressure water or steam sent to the regenerator 50 is cooled by the condenser 71 and returned to the water. Thereafter, the water is sent to the pump 72 and is circulated by being made into high-pressure water through the water supply pipe 51 and sent to the heat medium heating device 30.

  The power generation system described above is a novel power generation system that directly converts the rotational energy of the windmill into heat energy and extracts it as electric energy, and is different from the conventional wind power generation system. And, according to the power generation system P, it is possible to perform stable power generation without using an expensive storage battery by storing heat as heat using a heat accumulator because it is configured to convert heat into electrical energy. it can. Further, it is not necessary to provide a speed increaser as in the conventional wind power generation system, and it is possible to avoid a gearbox trouble that is likely to break down. Furthermore, an energy storage system equipped with a storage battery requires components such as a converter, which complicates the system and increases power loss. On the other hand, heat is stored in a regenerator to extract heat necessary for power generation. The heat storage system that can be made is simple and inexpensive.

  In the power generation system described above, the case where the heat medium is water has been described, but for example, oil, liquid metal (Na, Pb, etc.), liquid such as molten salt, and gas can be used as the heat medium. . When using a liquid metal other than water as the heat medium, for example, use a liquid metal or the like as the primary heat medium that circulates in the piping, and heat exchanger with the heat of the primary heat medium sent through the transport pipe The secondary heat medium (water) may be heated via the steam to generate steam.

  In addition, when using, for example, oil, liquid metal, or a molten salt having a boiling point of more than 100 ° C. at normal pressure as the heat medium flowing through the piping, when heated to more than 100 ° C. compared to water, It is easy to suppress an increase in internal pressure due to vaporization of the heat medium in the pipe.

  Note that the present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the gist of the present invention. For example, it is possible to appropriately change the shapes of the rotating body, the yoke and the conductor, and to appropriately change the materials used for these members.

  The windmill and its control method of the present invention can be suitably used for a wind energy conversion system including a windmill, for example.

1 Windmill 2 Rotational speed detector 3 Rotational speed control device
10 Blade 11 Rotating shaft 12 Hub
30 Heating medium heating device
31 Rotating body
311,312 Magnetic convex part 315 Support member
32 York
321,322 Magnetic protrusion
33 coils
34 Conductor 34i Insulation
35 Piping
50 Regenerator 51 Water supply pipe 52 Transport pipe
60 Power generation section 61 Steam turbine 62 Generator
71 Condenser 72 Pump
201 Tower 202 Nacelle 203 Anemometer
P Power generation system

Claims (4)

A windmill having blades and rotating in response to wind;
A rotational speed detector for detecting the rotational speed of the windmill;
A rotational speed control device for controlling the rotational speed of the windmill,
The said rotational speed control apparatus controls the rotational speed of the said windmill, when the rotational speed of the said windmill detected by the said rotational speed detector continues for a fixed time or more within a predetermined range. A variable pitch mechanism for adjusting the pitch angle of the blade;
The wind turbine according to claim 1, wherein the rotational speed control device controls the rotational speed of the wind turbine by adjusting a pitch angle of the blade by the variable pitch mechanism. A rotating shaft that rotates in conjunction with the windmill;
A rotating body supported by the rotating shaft;
A coil that generates a rotating magnetic field as the rotating body rotates,
A power source for energizing the coil;
A conductor through which an induced current caused by the magnetic flux of the rotating magnetic field flows,
The rotational speed control device controls an energization current from the power source to the coil and adjusts a torque in a direction to stop the rotation of the rotating body generated by an induced current flowing in the conductor. The wind turbine according to claim 1, wherein the rotational speed is controlled. A method for controlling a windmill having a blade and rotating in response to wind,
A method of controlling a windmill, comprising: controlling the rotational speed of the windmill when the windmill continuously rotates at a rotational speed within a predetermined range for a predetermined time or more.

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