Wind power generation system, control method therefor, and energy storage device

Abstract

To store regenerative power of a motor for rotating blades and use the stored power for motor drive, thereby reducing the amount of electric power supplied from the non-rotating side to the rotating side.SOLUTION: A wind power generation system includes: blades (22) that convert wind power into rotational force to rotate a main shaft (14) of a generator (6); a pitch angle calculation unit (integrated control unit 8) that calculates the pitch angle of the blades using control information including at least one or more of wind speed acting on the blades, stress acting on the main shaft, and rotation of the main shaft; a motor (servo motor 24) that controls the pitch angle by rotation through power supply and generates regenerative power by variation of the pitch angle; a non-contact transmission unit (rotary transformer 12) that non-contactingly transmits control information and power between a rotating section rotating together with the main shaft and a non-rotating section including the generator; and an energy storage (30) that supplies power to the motor, charges regenerative power from the motor, and charges power transmitted via the non-contact transmission unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a wind power generation system used for offshore power generation, for example, a control method thereof, and an energy storage device. [Background technology]

[0002] Wind power generation systems generate electricity by converting wind power into rotational force using blades. For this reason, controlling the pitch angle of the blades, which indicates their orientation relative to the wind direction, is extremely important for efficiently converting wind power into rotational force and for protecting the blades from strong winds.

[0003] It is known that this wind power generation system is provided with a pitch angle drive device for changing the pitch angle of the blades (for example, Patent Document 1).

[0004] In this wind power generation system, it is known that a pitch angle command value is calculated taking into consideration the amount of displacement of the pitch angle of the blades, and the pitch angle of the blades is changed (for example, Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-69797 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-67023 Summary of the Invention [Problem to be solved by the invention]

[0006] When a servo motor is used to control the blade pitch angle, the power required to rotate the servo motor is supplied, and control information for pitch angle control is used. Conventionally, slip rings and rotary transformers have been used to supply power to the servo motor on the blade side.

[0007] Slip rings energize the rotating and non-rotating sides by pressing non-rotating brushes against the rotating ring, which causes wear due to friction between the ring and brushes, posing a challenge to the durability of the brushes, etc. Maintenance such as brush replacement is extremely troublesome, especially in offshore power generation.

[0008] If a rotary transformer is used instead of this slip ring, it has the advantage of being highly wear-resistant and requiring less maintenance, since the rotary transformer does not have any frictional contact such as rings or brushes.

[0009] However, conventional rotary transformers require a large amount of power to control the pitch angle of the blades from the non-rotating side to the rotating side, which increases the coil size in proportion to the power, resulting in increased mass and cost.

[0010] Therefore, an object of the present disclosure is to store the regenerative power of the motor that rotates the blades and use this stored power when driving the motor, thereby reducing the amount of power supplied from the non-rotating side to the rotating side. [Means for solving the problem]

[0011] In order to achieve the above object, according to one aspect of the wind power generation system of the present disclosure, the system includes: blades that convert wind force into rotational force to rotate a main shaft of a generator; a pitch angle calculation unit that calculates a pitch angle of the blades using control information including at least one or more of wind speed acting on the blades, stress acting on the main shaft, and rotation of the main shaft; a motor that controls the pitch angle of the blades by rotating through power supply and generates regenerative power through fluctuations in the pitch angle; a rotating unit that rotates together with the main shaft and a non-rotating unit including the generator, a non-contact transmission unit that transmits the control information and power in a non-contact manner between the rotating unit that rotates together with the main shaft and a non-rotating unit including the generator; and an energy storage that supplies power to the motor, charges with the regenerative power from the motor, and charges with the power transmitted by the non-contact transmission unit.

[0012] The wind power generation system may further include a charge / discharge unit that sets a discharge region and a charge region of the energy storage in accordance with a variation in the pitch angle, discharges the energy storage in the discharge region as the pitch angle decreases to supply power to the motor, and charges the energy storage with the regenerative power in the charge region as the pitch angle increases.

[0013] This wind power generation system may further include a power supply unit, a voltage detection unit that detects a charging voltage of the energy storage, and a charging unit that charges the energy storage with power supplied from the power supply unit when the charging voltage drops to a lower threshold value.

[0014] This wind power generation system may further include a combining unit that combines at least the control information and the power to be supplied to the energy storage, and a separating unit that separates the control information and the power from the output of the combining unit.

[0015] In this wind power generation system, the energy storage may include either an electric double layer capacitor or an electric double layer capacitor module.

[0016] In order to achieve the above object, according to one aspect of the control method for a wind power generation system disclosed herein, the control method includes the steps of: a step in which the blades convert wind force into rotational force to rotate a main shaft of a generator; a step in which a pitch angle calculation unit calculates a pitch angle of the blades using control information including at least one or more of a wind speed acting on the blades, a stress acting on the main shaft, and a rotation of the main shaft; a step in which a motor rotates the blades by supplying power and controls the pitch angle of the blades; a step in which the motor generates regenerative power in response to the wind rotation of the blades; and a step in which a charge / discharge unit sets a discharge region and a charge region of an energy storage according to the rotation angle of the main shaft, discharges the energy storage in the discharge region, supplies the discharged power to the motor, and charges the energy storage with the regenerative power in the charge region.

[0017] This control method for a wind power generation system may further include a step in which a voltage detection unit detects a charging voltage of the energy storage, and a step in which a charging unit charges the energy storage when the charging voltage drops to a lower threshold.

[0018] To achieve the above object, according to one aspect of the energy storage device of the present disclosure, the energy storage device includes an electric double layer capacitor module that supplies power to a motor that rotates blades, and a charge / discharge unit that sets a discharge region and a charge region of the electric double layer capacitor module according to the rotation angle of the main shaft of a generator, discharges the electric double layer capacitor module in the discharge region and supplies the discharged power to the motor, and charges the electric double layer capacitor module with regenerative power from the motor in the charge region. [Effects of the Invention]

[0019] According to the present disclosure, any of the following effects can be obtained. (1) The regenerative power obtained from the motor in response to the wind-driven rotation of the blades is charged into the energy storage, and this discharged power is used to power the motor, thereby reducing the power supplied to the motor from the non-rotating side.

[0020] (2) Since the power capacity of a contactless power supply unit such as a rotary transformer that transmits power from the non-rotating side to the rotating side can be reduced, the size of power supply components such as the coil of the rotary transformer can be prevented from increasing, and the power supply equipment can be made smaller and lighter.

[0021] (3) The discharge and charge regions of the energy storage are set according to the rotation angle of the generator's main shaft. Discharged power is supplied to the motor in the discharge region, and regenerative power generated by the motor is charged to the energy storage in the charge region. This enables charging and effective use of the motor's regenerative power, reducing power loss, and also reducing the power capacity of the contactless power supply unit, since the shortfall in power required to rotate the motor can be supplied to the energy storage from the non-rotating side.

[0022] (4) Energy storage can be configured using electric double layer capacitors or electric double layer capacitor modules, which have excellent charging and discharging properties, and can store regenerative power generated by the motor and make effective use of it. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a diagram showing a wind power generation system according to an embodiment. [Figure 2] FIG. 2 is a block diagram showing the blade control unit. [Figure 3] FIG. 3A is a cross-sectional view showing the blade, and FIG. 3B is a diagram showing the rotation angle of the main shaft, the transition of the pitch angle, and the charge / discharge region. [Figure 4] FIG. 4 is a diagram showing the rotation angle of the main shaft, the transition of the pitch angle, and the charge / discharge region corresponding to B in FIG. [Figure 5] FIG. 5 is a diagram illustrating an example of a signal processing unit according to the first embodiment. [Figure 6] FIG. 6 is a diagram illustrating signal synthesis. [Figure 7] FIG. 7 is a diagram illustrating signal separation. [Figure 8]FIG. 8A is a diagram illustrating a rotary transformer according to a second embodiment, and FIG. 8B is a vertical cross-sectional view illustrating the rotary transformer. DETAILED DESCRIPTION OF THE INVENTION

[0024] <Wind power generation system 2> 1 shows a wind power generation system 2 according to an embodiment of the present disclosure. This wind power generation system 2 is an example, and the present disclosure is not limited to the configuration shown in FIG.

[0025] The wind power generation system 2 shown in Fig. 1 includes a non-rotating section 4-1 and a rotating section 4-2. The non-rotating section 4-1 is fixed to the ground, the ocean, a ship, or the like by a support (not shown) or the like. The non-rotating section 4-1 is equipped with a generator 6, an integrated control section 8, a primary circuit section 10, and a part of a rotary transformer 12.

[0026] The generator 6 is a wind power generator that receives rotational force from the rotating part 4-2 on the main shaft 14 via a gear (not shown) and generates electricity using this rotational force. The generator 6 has a well-known configuration that converts the rotation of the main shaft 14 into electric power.

[0027] The integrated control unit 8 includes a computer system, and acquires physical information such as torque information, stress information, wind information, power information, and pitch angle information as examples of control information for the wind power generation system 2, stores the information in the storage unit 16, and generates control information using the stored information in the storage unit 16. Therefore, the integrated control unit 8 is an example of a pitch angle calculation unit of the present disclosure.

[0028] The storage unit 16 is equipped with memory elements such as a ROM (Read-Only Memory) and a RAM (Random-Access Memory), and the ROM (Read-Only Memory) stores various programs such as an OS (Operating System) and control programs. These programs include a database that stores control information including physical information such as torque information, stress information, wind information, power information, and pitch angle information.

[0029] The primary circuit unit 10 has a power supply function and a signal processing function. The power supply function is a function of outputting AC or DC power and supplying it to a load. The signal processing function is a function of combining control information and power and a function of separating the control information and power from the combined output.

[0030] The rotary transformer 12 is an example of a non-contact transmission unit of the present disclosure. It is installed between the non-rotating unit 4-1 and the rotating unit 4-2 and transmits the aforementioned power and other signals from the non-rotating unit 4-1 to the rotating unit 4-2 and from the rotating unit 4-2 to the non-rotating unit 4-1 in a non-contact manner. The rotary transformer 12 has a primary coil 18-1 on the non-rotating unit 4-1 side and a secondary coil 18-2 on the rotating unit 4-2 side. The primary coil 18-1 and secondary coil 18-2 face each other with a gap 20 between them. The primary coil 18-1 is an example of the first coil of the present disclosure, and the secondary coil 18-2 is an example of the second coil of the present disclosure. An electromagnetic coupling is established between the primary coil 18-1 and the secondary coil 18-2, which rotates together with the main shaft 14. This electromagnetic coupling allows for the transmission of control information and power without mechanical contact.

[0031] On the rotating section 4-2 side, blades 22-1, 22-2, and 22-3, servo motors 24-1, 24-2, and 24-3, a torque / stress sensor 26, a secondary circuit section 28, and an energy storage 30 are installed.

[0032] The wind turbine comprises a plurality of blades 22, for example, three blades 22-1, 22-2, and 22-3 arranged radially at an angle of 120 degrees around the main shaft 14. Each of the blades 22-1, 22-2, and 22-3 receives wind force and converts it into rotational force, which then rotates the main shaft 14.

[0033] The blade 22-1 is provided with a rotating shaft 23 of a servo motor 24-1, which is an example of a motor according to the present disclosure, the blade 22-2 is provided with a rotating shaft 23 of a servo motor 24-2, and the blade 22-3 is provided with a rotating shaft 23 of a servo motor 24-3, all of which are attached via gears not shown.

[0034] Each of the servo motors 24-1, 24-2, and 24-3 generates a rotational force when supplied with electric power, and generates regenerative electric power when the power supply is cut off and the motor receives a rotational force due to the wind rotation of the blades 22-1, 22-2, and 22-3. In other words, each of the servo motors 24-1, 24-2, and 24-3 serves as a rotation drive means that generates a rotational force when power is supplied and controls each of the blades 22-1, 22-2, and 22-3 to an optimum pitch angle, and when the power supply is cut off, the servo motors rotate due to the wind rotation of the blades 22-1, 22-2, and 22-3, and serve as a power generation means that receives the rotation and generates regenerative electric power.

[0035] Since each of the servo motors 24-1, 24-2, and 24-3 is independently controlled for each of the blades 22-1, 22-2, and 22-3, an optimal pitch angle θp is set for each of the blades 22-1, 22-2, and 22-3. Furthermore, the regenerative power obtained by each of the servo motors 24-1, 24-2, and 24-3 is stored in the energy storage 30 and can be effectively used as drive power for each of the servo motors 24-1, 24-2, and 24-3.

[0036] The torque / stress sensor 26 is installed on the main shaft 14 on the rotating part 4-2 side, and detects the torque and stress applied to the main shaft 14 when the main shaft is rotating, and outputs the detection signal. In this example, the torque / stress sensor 26 is used, but either a torque sensor or a stress sensor may be used. The torque / stress sensor 26 may also be installed on the non-rotating part 4-1 side. The output of this torque / stress sensor 26 is then provided to the secondary circuit part 28 in a timely manner and used to calculate pitch angle information.

[0037] The secondary circuit unit 28 has a power supply function, a signal processing function, and a pitch angle control function. The power supply function and the signal processing function have the same configurations as those of the primary circuit unit 10. The pitch angle control function receives control information and changes the pitch angle according to the rotation angle of the main shaft 14, and an optimal pitch angle is set for each of the blades 22-1, 22-2, and 22-3.

[0038] The energy storage 30 is a discharging means for supplying discharge power to each of the servo motors 24-1, 24-2, and 24-3, and also constitutes a power storage means for storing regenerative power obtained from each of the servo motors 24-1, 24-2, and 24-3. For this energy storage 30, an electric double layer capacitor having excellent charge / discharge characteristics or an electric double layer capacitor module including an electric double layer capacitor is used.

[0039] <Blade Control Unit 32 and Its Control> The generator 6 that generates electricity using wind power is equipped with a blade control unit 32 that controls each of the blades 22-1, 22-2, and 22-3 to increase the efficiency of wind power generation. The blade control unit 32 includes, as an example, the integrated control unit 8, the primary circuit unit 10, the rotary transformer 12, the memory unit 16, the torque / stress sensor 26, the secondary circuit unit 28, and the energy storage 30.

[0040] The control by the blade control unit 32 includes the following controls. (1) Controlling the pitch angle of each blade 22-1, 22-2, and 22-3 (2) Discharging the energy storage 30 and controlling the drive of the servo motors 24-1, 24-2, and 24-3 with the discharged power. (3) Controlling the recovery of regenerative power generated in the servo motors 24-1, 24-2, and 24-3 by rotating the blades 22-1, 22-2, and 22-3 in a wind-power rotation state (4) Charging control for charging the energy storage 30 to a charging voltage within a range between a lower threshold and an upper threshold.

[0041] Fig. 2 shows an example of the blade control unit 32. In Fig. 2, the same parts as in Fig. 1 are given the same reference numerals, and the description thereof will be omitted.

[0042] <(1) Pitch angle control of each blade 22-1, 22-2, 22-3> The primary circuit unit 10 includes a power supply unit 34-1, a signal processing unit 36-1, etc. The power supply unit 34-1 constitutes a primary power supply that supplies the power necessary to power the blades 22-1, 22-2, and 22-3. This power supply unit 34-1 is formed, for example, by an AC power supply.

[0043] The signal processing unit 36-1 performs synthesis processing such as modulation of the carrier signal and control information required for pitch angle control, including AC power supplied from the power supply unit 34-1 and pitch angle control information provided by the integrated control unit 8. The synthesized output obtained by this signal processing unit 36-1 is applied to the primary coil 18-1 of the rotary transformer 12 on the non-rotating side.

[0044] As already mentioned, the rotary transformer 12 is an example of a non-contact transmission unit of the present disclosure, and is equipped with a primary coil 18-1 and a secondary coil 18-2. Control information and power are transmitted between the non-rotating unit 4-1 and the rotating unit 4-2 by electromagnetic coupling between the primary coil 18-1 and the secondary coil 18-2, and the transmission output from the primary circuit unit 10 is transmitted to the secondary circuit unit 28.

[0045] The secondary circuit unit 28 is provided with a motor driver 38-1 corresponding to the servo motor 24-1, a motor driver 38-2 corresponding to the servo motor 24-2, a motor driver 38-3 corresponding to the servo motor 24-3, and a charge / discharge unit 39. The charge / discharge unit 39 sets a discharge region and a charge region for the energy storage 30 in accordance with fluctuations in the pitch angle θp, and discharges the energy storage 30 in the discharge region as the pitch angle θp decreases to supply power to the servo motors 24-1, 24-2, and 24-3, and charges the energy storage 30 with regenerative power in the charge region as the pitch angle θp increases. To perform this charging and discharging, the charge / discharge unit 39 is provided with a bidirectional power supply circuit 40-1 corresponding to the servo motor 24-1, a bidirectional power supply circuit 40-2 corresponding to the servo motor 24-2, and a bidirectional power supply circuit 40-3 corresponding to the servo motor 24-3.

[0046] In the figure, arrows pointing from energy storage 30 to servo motors 24-1, 24-2, and 24-3 indicate the discharge power of energy storage 30, and arrows pointing from servo motors 24-1, 24-2, and 24-3 to energy storage 30 indicate regenerative power. In other words, when energy storage 30 is discharging, discharge power is supplied to servo motor 24-1 via bidirectional power supply circuit 40-1 and motor driver 38-1, discharge power is supplied to servo motor 24-2 via bidirectional power supply circuit 40-2 and motor driver 38-2, and similarly, discharge power is supplied to servo motor 24-3 via bidirectional power supply circuit 40-3 and motor driver 38-3.

[0047] The regenerative power obtained by the servo motor 24-1 is charged into the energy storage 30 via the motor driver 38-1 and the bidirectional power supply circuit 40-1, and the regenerative power obtained by the servo motor 24-2 is charged into the energy storage 30 via the motor driver 38-2 and the bidirectional power supply circuit 40-2. Similarly, the regenerative power obtained by the servo motor 24-3 is charged into the energy storage 30 via the motor driver 38-3 and the bidirectional power supply circuit 40-3.

[0048] The signal processing unit 36-2 receives AC power supplied from the power supply unit 34-1, control signals such as pitch angle control information, and other signals from the secondary coil 18-2 of the rotary transformer 12, and also receives detected torque and stress outputs from the torque / stress sensor 26. This signal processing unit 36-2 includes a signal separation function, an AC / DC conversion function that converts AC power to DC power, and a pitch angle control function. The signal separation function performs signal processing such as demodulation of the AC power from the power supply unit 34-1, control information required for pitch angle control, and carrier signals. The AC / DC conversion function converts the AC signal received from the secondary coil 18-2 into a DC signal.

[0049] The pitch angle control unit 42 receives control information necessary for pitch angle control from the signal processing unit 36-2, calculates the pitch angle θp, and performs pitch angle control. For this pitch angle control, the pitch angle θp is calculated using control information including one or more of the wind speed acting on the blades 22-1, 22-2, and 22-3, the stress acting on the main shaft 14, and the rotation of the main shaft 14.

[0050] The motor drivers 38-1, 38-2, 38-3 and bidirectional power supply circuits 40-1, 40-2, 40-3 receive pitch angle information from the pitch angle control unit 42 and provide drive outputs to the servo motors 24-1, 24-2, 24-3 for controlling the pitch angles to the optimum angles.

[0051] <(2) Drive control of servo motors 24-1, 24-2, and 24-3> The energy storage 30 is put into a discharging state in accordance with the rotation angle of the spindle 14, and this discharged power is supplied to each of the servo motors 24-1, 24-2, 24-3 by the motor drivers 38-1, 38-2, 38-3 and the bidirectional power supply circuits 40-1, 40-2, 40-3. In other words, the above-described pitch angle control is executed when the energy storage 30 is discharging and when this discharged power is being supplied to the servo motors 24-1, 24-2, 24-3.

[0052] (3) Regenerative power recovery control The blades 22-1, 22-2, and 22-3 are set to a free rotation state according to the rotation angle of the main shaft 14, and the rotation of the blades 22-1, 22-2, and 22-3 due to wind rotation causes the servo motors 24-1, 24-2, and 24-3 to generate regenerative power. This regenerative power is collected in the energy storage 30.

[0053] <(4) Charging control of the energy storage 30> This charging control uses a power supply unit 34-2, a charging voltage detection unit 44, and a charging control unit 46. The power supply unit 34-2 converts AC power received from the secondary coil 18-2 of the rotary transformer 12 into DC power, and the charging control unit 46 causes the power supply unit 34-2 to generate DC power required to charge the energy storage 30 when the charging voltage of the energy storage 30 drops to a lower limit voltage.

[0054] The charging voltage detection unit 44 monitors the charging voltage of the energy storage 30 and supplies this charging voltage information to the charging control unit 46 .

[0055] The charging control unit 46 is set with a lower threshold and an upper threshold for the charging voltage of the energy storage 30, and monitors the charging voltage of the energy storage 30. When the charging voltage drops to the lower threshold, the charging control unit 46 supplies the power required for charging from the power supply unit 34-2 to the energy storage 30, and charges the charging voltage up to the upper threshold. This charging is performed from the power supply unit 34-2 using one or more of the bidirectional power supply circuits 40-1, 40-2, and 40-3. The power supply unit 34-2 and the bidirectional power supply circuits 40-1, 40-2, and 40-3 constitute the charging / discharging unit 40 of the energy storage 30. This charging / discharging unit 40 is an example of a charging unit of the present disclosure.

[0056] <Energy Storage Device 48> In the secondary circuit section 28, a power supply section 34-2, bidirectional power supply circuits 40-1, 40-2, 40-3, a charging voltage detection section 44, and a charging control section 46 are used to charge the energy storage 30, and an energy storage device 48 is configured.

[0057] <Blade 22> FIG. 3A shows a cross section of the blades 22 (=22-1, 22-2, 22-3) cut in a direction perpendicular to the central axis of lift.

[0058] For the blade 22, Fu is the lift of the blade 22, O1 is the center of lift which is the reference point of the lift Fu, Bv is the rotational speed of the blade 22, Va is the wind speed acting on the blade 22, Rw is the relative wind direction, θp is the pitch angle of the blade 22 based on the main shaft 14, and θu is the angle between the center of lift O1 and the wind direction Rw and the reference line L connecting the leading edge 22a and the trailing edge 22b of the blade 22.

[0059] In this blade 22, the center of rotation O2 of the blade 22 is set at a midpoint on the reference line L between the center of lift O1 and the leading edge 22a of the blade 22. Rotation is imparted to the center of rotation O2 by servo motors 24 (=24-1, 24-2, 24-3).

[0060] In this way, the center of rotation O2 of the blade 22 is set on the leading edge 22a side of the center of lift O1 of the lift Fu received by the blade 22, and the torque τ required to change the pitch angle θp is determined by the deviation between the center of lift O1 and the center of rotation O2.

[0061] <Changes in the rotation angle θ of the main shaft 14, the pitch angle θp of each of the blades 22-1, 22-2, and 22-3, and the charge / discharge region of the energy storage device 30>

[0062] 3B, the horizontal axis represents the rotation angle θ of the main shaft 14 and the vertical axis represents the pitch angle θp, and the horizontal axis shows the transition of the pitch angle θp relative to the rotation angle θ of the main shaft 14. Also, FIG. 4 shows the rotation angle θ and pitch angle θp of the main shaft 14.

[0063] 3B is an example showing the relationship between the rotation angle θ and the pitch angle θp of the main shaft 14, and the relationship (optimum phase) between the rotation angle θ and the pitch angle θp constantly changes depending on the wind speed. In other words, the power supply drive range (capacitor charging range) and regenerative power range (capacitor discharging range) for the servo motor 24-1 are determined by the direction in which the pitch angle θp is changed. Specifically, when the pitch angle θp increases, the regenerative power generated in the servo motors 24-1, 24-2, and 24-3 is charged to the energy storage 30, and when the pitch angle θp decreases, the energy storage 30 is discharged and this discharged power is supplied to the servo motors 24-1, 24-2, and 24-3.

[0064] In this example, when the rotation angle θ of the main shaft 14 is 0° or 360°, the blades 22-1, 22-2, and 22-3 are positioned at their lowest positions, where the wind force they receive is minimized. In contrast, when the rotation angle θ is 180°, the blades 22-1, 22-2, and 22-3 are positioned at their highest positions, where the wind force they receive is maximized. In other words, the wind force acting on the blades 22-1, 22-2, and 22-3 increases from the bottom to the top, and the pitch angle θp increases parabolically in accordance with this transition. P1, P2, and P3 indicate the points through which the pitch angle θp and rotation angle θ pass.

[0065] By controlling this pitch angle θp, the wind force required for power generation can be applied to each of the blades 22-1, 22-2, and 22-3, thereby improving power generation efficiency.

[0066] <Control of wind power generation system 2> The control of this wind power generation system 2 includes a process of rotating the main shaft 14, a process of calculating the pitch angle θp, a process of controlling the pitch angle θp, a process of recovering regenerative power, a process of transmitting control information, etc., and a process of charging and discharging the energy storage 30.

[0067] Rotation process of main shaft 14: The blades 22-1, 22-2, and 22-3 receive wind power, convert the wind power into rotational power, and rotate the main shaft 14 of the generator 6. As a result, the generator 6 generates electricity in response to the rotation of the main shaft 14.

[0068] Pitch angle θp calculation process: The integrated control unit 8, which is an example of a pitch angle calculation unit, calculates the pitch angle θp of each of the blades 22-1, 22-2, and 22-3 using control information including one or more of the wind speed acting on the blades 22-1, 22-2, and 22-3, the stress acting on the main shaft 14, and the rotation of the main shaft 14.

[0069] Control process of pitch angle θp: When power is supplied, the blade control unit 32 controls the pitch angle θp of each of the blades 22-1, 22-2, 22-3 to the optimum pitch angle θp by the servo motors 24-1, 24-2, 24-3.

[0070] Regenerative power recovery process: When not powered, the servo motors 24-1, 24-2, and 24-3 generate regenerative power by receiving wind-force rotation of the blades 22-1, 22-2, and 22-3. This regenerative power is recovered in the energy storage 30 via the motor drivers 38-1, 38-2, and 38-3 and the bidirectional power supply circuits 40-1, 40-2, and 40-3.

[0071] Transmission process of control information, etc.: The rotary transformer 12 transmits power including control information contactlessly between the rotating part 4-2, which includes the energy storage 30 and rotates together with the main shaft 14, and the non-rotating part 4-1, which includes the generator 6.

[0072] Charging and discharging process of energy storage 30: The secondary circuit unit 28 sets a discharging region and a charging region of the energy storage 30 at the rotation angle θ of the main shaft 14, discharges the energy storage 30 in the discharging region, supplies this discharged power to the servo motors 24-1, 24-2, and 24-3, and charges the energy storage 30 with regenerative power from the servo motors 24-1, 24-2, and 24-3 in the charging region.

[0073] <Charging and discharging of the energy storage device 48> The charging and discharging of the energy storage device 48 includes a charging and discharging process of the energy storage 30, a power supply process, a discharging process, and a charging process.

[0074] Charging and discharging process of the energy storage 30: When discharging, the energy storage 30 generates discharge power, and when charging, the energy storage 30 is charged with the regenerative power of the servo motors 24-1, 24-2, and 24-3.

[0075] Power supply process: The bidirectional power supply circuits 40-1, 40-2, and 40-3 set the discharge region and charge region of the energy storage 30 at the rotation angle θ of the main shaft 14 of the generator 6, discharge the energy storage 30 in the discharge region, and supply this discharged power to the servo motors 24-1, 24-2, and 24-3.

[0076] Discharge step: The bidirectional power supply circuits 40-1, 40-2, and 40-3 discharge the energy storage 30 in the discharge region.

[0077] Charging step: In the charging area, the energy storage 30 is charged with the regenerative power of the servo motors 24-1, 24-2, and 24-3.

[0078] <Effects of the embodiment> According to this embodiment, one of the following effects can be obtained. (1) When the blades 22-1, 22-2, and 22-3 receive wind power, the servo motors 24-1, 24-2, and 24-3 are rotated by the wind and the regenerative power is charged into the energy storage 30. The discharged power of the energy storage 30 can be used to power the servo motors 24-1, 24-2, and 24-3. This allows for effective use of electrical energy.

[0079] (2) The power stored in the energy storage 30 in the rotating unit 4-2 can be used to drive the servo motors 24-1, 24-2, and 24-3, which reduces the power supplied from the non-rotating unit 4-1. In other words, the power supplied from the non-rotating unit 4-1 to drive the servo motors 24-1, 24-2, and 24-3 in the rotating unit 4-2 can be reduced.

[0080] (3) Since the power supply from the non-rotating part 4-1 to the rotating part 4-2 can be reduced, the power capacity of the rotary transformer can be reduced, the primary coil 18-1 and the secondary coil 18-2 can be prevented from becoming larger, and the power supply equipment can be made smaller and lighter.

[0081] (4) The power supply from the non-rotating part 4-1 to the rotating part 4-2 can be reduced, the power supply capacity of the power supply part 34-1 in the primary circuit part 10 can be reduced, and the power supply equipment can be made smaller and lighter.

[0082] (5) The energy storage 30 can be configured using an electric double layer capacitor or an electric double layer capacitor module that has excellent charging and discharging properties, and can store and effectively utilize the regenerative power generated by the motor.

[0083] (6) The regenerative power of the servo motors 24-1, 24-2, and 24-3 can be used as drive power in the rotating unit 4-2. In other words, the rotating unit 4-2 can be made self-operating, which reduces the maintenance of the wind power generation system and makes it possible to realize a system that is suitable for offshore power generation, etc. [Example]

[0084] FIG. 5 shows an example of the signal processing units 36-1 and 36-2. The signal processing units 36-1 and 36-2 include a signal synthesis unit 50 and a signal separation unit 52, and are provided with a bidirectional function, and perform signal processing required for bidirectional communication of electrical signals using the rotary transformer 12.

[0085] The signal synthesizer 50 superimposes and synthesizes a power signal S1, a carrier signal S2, and a control signal S3 as multiple signals used for controlling the pitch angle θp of the blades 22-1, 22-2, and 22-3 and for supplying power to the servo motors 24-1, 24-2, and 24-3, to generate a synthesized signal Sout. This signal synthesis may be performed using a modulation circuit such as an amplitude modulation (AM) circuit or a frequency modulation (FM) circuit.

[0086] The signal separator 52 separates the power signal S1', carrier signal S2', and control signal S3' from the combined signal Sin, and reproduces each signal. Taking note of the fact that the power signal S1', carrier signal S2', and control signal S3' have different frequencies, the signal separator 52 is equipped with a low-pass filter (LPF) 54 that passes the power signal S1', a band-pass filter (BPF) 56 that passes the carrier signal S2', and a high-pass filter (HPF) 58 that passes the control signal S3'. Therefore, the signal separator 52 performs signal separation processing, such as demodulation processing, corresponding to the signal synthesis, and separates the power signal S1', carrier signal S2', and control signal S3' from the combined signal Sin.

[0087] <Signal synthesis> FIG. 6 shows an example of signal synthesis processing by the signal synthesis unit 50, with the horizontal axis representing time t and the vertical axis representing signal amplitude.

[0088] As shown in FIG. 6, the power signal S1 (A in FIG. 6), the carrier signal S2 (B in FIG. 6), and the control signal S3 (C in FIG. 6) are applied to the signal synthesis unit 50, where the signals are synthesized by modulation processing or the like, and are synthesized into a synthesized signal Sout (D in FIG. 6).

[0089] <Signal separation> FIG. 7 shows an example of signal separation processing by the signal separation unit 52, with the horizontal axis representing time t and the vertical axis representing signal amplitude, etc.

[0090] As shown in Figure 7, when the composite signal Sin (A in Figure 7) is applied to the signal separation unit 52, the composite signal Sin can be separated into a power signal S1' (B in Figure 7) through the LPF 54, a carrier signal S2' (C in Figure 7) through the BPF 56, and a control signal S3' (D in Figure 7) through the HPF 58 according to the frequency components, and can be extracted.

[0091] <Effects of Example 1> According to the first embodiment, any of the following effects can be obtained. (1) The signal processing units 36-1 and 36-2 can combine or separate multiple signals used to control the pitch angle θp of the blades 22-1, 22-2, and 22-3, and to supply the power required to the servo motors 24-1, 24-2, and 24-3. This allows for bidirectional signal transmission, and simplifies the signal transmission, making it possible to easily transmit signals using a single rotary transformer 12, for example.

[0092] (2) For example, the signal separator 52 of the signal processor 36-2 can separate the signal combined by the signal combiner 50 of the signal processor 36-1 into desired signals based on frequency, thereby reproducing the signal before combination.

[0093] (3) For signal transmission, such as carrier signals S2 and S2' transmitted through the rotary transformer 12, a high-impedance circuit enables low-power transmission. Because a large current is required for power transmission, the rotary transformer 12 must operate in a low-impedance region. For signal transmission, a relatively large impedance is required to reduce the current and ensure sufficient voltage. Specifically, a parallel resonant circuit is formed by connecting capacitors (not shown) in parallel with the primary coil 18-1 and secondary coil 18-2 of the rotary transformer 12, and the resonant frequency is set much higher than the power transmission frequency. Since the impedance is maximized at this resonant frequency, voltage transmission is possible with almost no power required. Since an excessively high impedance makes the system susceptible to noise, using a carrier frequency close to the resonant frequency enables signal transmission with low power consumption and high noise resistance. [Example]

[0094] Fig. 8A shows a rotary transformer 12 according to Example 2. In Fig. 8A, the same parts as in Fig. 1 are denoted by the same reference numerals.

[0095] The rotary transformer 12 is installed on the main shaft 14 of the generator 6, and includes a coil bearing holder 60-1 fixed to the non-rotating part 4-1, and a coil bearing holder 60-2 fixed to the main shaft 14 and rotating together with the main shaft 14. The coil bearing holder 60-1 is an example of a fixed-side housing, and the coil bearing holder 60-2 is an example of a rotating-side housing. The coil bearing holder 60-1 is fixed to a member of the non-rotating part 4-1 by fixing legs 62.

[0096] The coil / bearing holder 60-1 is provided with a coil terminal 64-1 drawn from the primary coil 18-1, and the coil / bearing holder 60-2 is provided with a coil terminal 64-2 drawn from the secondary coil 18-2. During rotation, signals are transmitted between the coil terminals 64-1 and 64-2.

[0097] Fig. 8B shows a vertical cross section of the rotary transformer 12 according to Example 2. In Fig. 8B, the same parts as in Fig. 8A are denoted by the same reference numerals.

[0098] The coil bearing holder 60-2 fixed to the main shaft 14 rotates together with the main shaft 14. A bearing holder extension 66 is installed on the coil bearing holder 60-1, and a pair of bearings 68-1 and 68-2 that rotatably support the coil bearing holder 60-2 are installed between the bearing holder extension 66 and the coil bearing holder 60-2.

[0099] The primary coil 18-1 and field yoke 70-1 are installed on the coil / bearing holder 60-1 side, and the secondary coil 18-2 and field yoke 70-2 are installed on the coil / bearing holder 60-2 side. The primary coil 18-1 is wound around the field yoke 70-1, and the secondary coil 18-2 is wound around the field yoke 70-2.

[0100] A gap 20 is set between the primary coil 18-1 and field yoke 70-1 and the secondary coil 18-2 and field yoke 70-2.

[0101] The primary coil 18-1 and field yoke 70-1 are maintained in a non-rotating state by the coil bearing holder 60-1, whereas the secondary coil 18-2 and field yoke 70-2 are maintained in a rotatable state by the coil bearing holder 60-2 and rotate together with the main shaft 14. During this rotation, the primary coil 18-1 and field yoke 70-1 and the secondary coil 18-2 and field yoke 70-2 are electromagnetically coupled via magnetic flux across the gap 20.

[0102] In the rotary transformer 12 shown in FIG. 8B, if the diameter of the main shaft 14 is φN, the width of the primary coil 18-1 and the secondary coil 18-2 is d, and the winding thickness is W, then φN > d, W, and the primary coil 18-1 and the secondary coil 18-2 are smaller than the main shaft 14, and the proportion of the rotary transformer 12 occupied by the primary coil 18-1 and the secondary coil 18-2 is small.

[0103] By configuring the frequencies of carrier signals S2 and S2' to match the resonant frequencies of primary coil 18-1 and secondary coil 18-2 in this way, primary coil 18-1 and secondary coil 18-2 can be made smaller, and the volume of rotary transformer 12 can be reduced.

[0104] <Effects of Example 2> According to the second embodiment, one of the following effects can be obtained. (1) A single rotary transformer 12 can be used to transmit multiple signals used for controlling the pitch angle θp of the blades 22-1, 22-2, and 22-3, for power supply to the servo motors 24-1, 24-2, and 24-3, and the like.

[0105] (2) The primary coil 18-1 and the secondary coil 18-2 in the rotary transformer 12 can be made smaller, and the volume of the rotary transformer 12 in the wind power generation system 2 can be reduced.

[0106] Other Embodiments The present disclosure includes the following embodiments.

[0107] (1) In the wind power generation system 2, one rotary transformer 12 is installed, but a plurality of rotary transformers 12 may be used.

[0108] (2) In the wind power generation system 2, information and power are transmitted using the rotary transformer 12. However, it is also possible to use a wireless transmission means for transmitting information and transmit only power using the rotary transformer 12.

[0109] As explained above, the most preferred embodiments of the present disclosure have been described, but the present disclosure is not limited to the above description, and various modifications and changes can be made by those skilled in the art based on the gist of the invention as set forth in the claims or disclosed in the specification. It goes without saying that such modifications and changes are included in the scope of the present disclosure. [Industrial Applicability]

[0110] According to the present disclosure, by charging the regenerative power of the motor, which generates power in response to the rotation of the blades, into an energy storage device and using this discharged power to power the motor, the amount of power supplied from the non-rotating side to the rotating side motor can be reduced, thereby providing a highly convenient wind power generation system. [Explanation of symbols]

[0111] 2. Wind power generation system 4-1 Non-rotating part 4-2 Rotating part 6. Generator 8 Integrated control unit 10 Primary circuit section 12 rotary transformer 14 Spindle 16 Memory section 18-1 Primary coil 18-2 Secondary coil 20 Gap 22-1, 22-2, 22-3 Blades 23 Rotation axis 24-1, 24-2, 24-3 servo motors 26 Torque and stress sensors 28 Secondary circuit section 30 Energy Storage 32 Blade control section 34-1, 34-2 Power supply section 36-1, 36-2 Signal processing section 38-1, 38-2, 38-3 Motor drivers 39 Charge / discharge section 40-1, 40-2, 40-3 Bidirectional power circuit 42 Pitch angle control unit 44 Charging voltage detection section 46 Charging control unit 48 Energy Storage Devices 50 Signal synthesis unit 52 Signal separation section 60-1, 60-2 Coil Bearing Folder 62 Fixed legs 64-1, 64-2 Coil terminals 66 Bearing Folder Extension 68-1, 68-2 bearings 70-1, 70-2 field yoke

Claims

1. Blades that convert wind power into rotational force to rotate the main shaft of the generator, a pitch angle calculation unit that calculates a pitch angle of the blades using control information including at least one or more of a wind speed acting on the blades, a stress acting on the main shaft, and a rotation of the main shaft; a motor that controls the pitch angle of the blades by rotating with power supply and generates regenerative power by varying the pitch angle; a non-contact transmission unit that transmits the control information and power in a non-contact manner between a rotating unit that rotates together with the main shaft and a non-rotating unit including the generator; an energy storage that supplies power to the motor, that is charged with the regenerative power from the motor, and that is charged with the power transmitted by the non-contact transmission unit; A wind power generation system, including:

2. 2. The wind power generation system according to claim 1, further comprising a charge / discharge unit that sets a discharge region and a charge region of the energy storage in accordance with a variation in the pitch angle, discharges the energy storage in the discharge region as the pitch angle decreases to supply power to the motor, and charges the energy storage with the regenerative power in the charge region as the pitch angle increases.

3. Furthermore, a power supply unit; a voltage detection unit that detects a charging voltage of the energy storage; a charging unit that charges the energy storage with power supplied from the power supply unit when the charging voltage drops to a lower threshold; The wind power generation system of claim 1 , comprising:

4. a combining unit that combines at least the control information and the power supplied to the energy storage; a separator that separates the control information and the power from the output of the combiner; The wind power generation system of claim 1 , comprising:

5. The wind power generation system according to claim 1 , wherein the energy storage includes either an electric double layer capacitor or an electric double layer capacitor module.

6. a step in which the blades convert wind power into rotational power to rotate a main shaft of a generator; a step in which a pitch angle calculation unit calculates a pitch angle of the blades using control information including at least one or more of a wind speed acting on the blades, a stress acting on the main shaft, and a rotation of the main shaft; a step of rotating the blades by a motor by supplying power and controlling the pitch angle of the blades; a step of the motor generating regenerative power by receiving wind-force rotation of the blades; a charging / discharging unit setting a discharge region and a charge region of an energy storage in accordance with a rotation angle of the main shaft, discharging the energy storage in the discharge region to supply the discharged power to the motor, and charging the energy storage with the regenerative power in the charge region; A method for controlling a wind power generation system, comprising:

7. Further, a voltage detection unit detects a charging voltage of the energy storage; a charging unit charging the energy storage when the charging voltage drops to a lower threshold; The method for controlling a wind power generation system according to claim 6, comprising:

8. an electric double layer capacitor module that supplies power to a motor that rotates the blades; a charge / discharge unit that sets a discharge region and a charge region of the electric double layer capacitor module according to a rotation angle of a main shaft of a generator, discharges the electric double layer capacitor module in the discharge region, supplies the discharged power to the motor, and charges the electric double layer capacitor module with regenerative power of the motor in the charge region; 1. An energy storage device comprising:

Images