Wind turbine braking control device and wind turbine

Abstract

To suppress breakage of a ring gear due to a sudden fluctuation of a load acting on the ring gear of a windmill.SOLUTION: A windmill brake control device includes: an electromagnetic brake which brakes at least one of relative rotation between a pinion gear installed in a first structure out of the first structure and a second structure for constituting a movable portion of a windmill and a ring gear installed in the second structure, and rotation of a motor on which the pinion gear is mounted; and a non-contact relay which is arranged on a power source line between a power source for operating the electromagnetic brake and the electromagnetic brake, and which opens / closes the power source line.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a wind turbine braking control device and a wind turbine.

Background Art

[0002] In a wind turbine used in a wind power generation device or the like, yaw control is performed to turn the rotor and nacelle of the wind turbine according to the wind direction in order to efficiently rotate the blades of the wind turbine. In yaw control, for example, a driving force (that is, a load) is transmitted from a driving device provided in the nacelle to a ring gear provided at the upper end in the tower, so that the driving device is turned together with the nacelle.

[0003] In order to hold the nacelle at the position after turning by yaw control, the wind turbine is provided with an electromagnetic brake that brakes the rotation of the drive shaft of the drive device, for example, as shown in Patent Document 1.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Due to sudden changes in the wind direction and wind speed, the load acting on the ring gear from the drive device may suddenly fluctuate. In order to suppress damage to the ring gear due to sudden fluctuations in the load acting on the ring gear, it is required to immediately release the electromagnetic brake.

[0006] However, conventionally, since an electromagnetic contactor has been used to open and close the electromagnetic brake, it has been difficult to immediately release the electromagnetic brake.

[0007] The present invention has been made in consideration of such points, and an object thereof is to provide a windmill braking control device and a windmill that can suppress damage to a ring gear due to a sudden change in the load acting on the ring gear of the windmill.

Means for Solving the Problems

[0008] The present invention relates to at least one of the relative rotation between a pinion gear installed on the first structure and a ring gear installed on the second structure among the first structure and the second structure constituting the movable part of the windmill, and the rotation of a motor to which the pinion gear is attached. An electromagnetic brake for braking, A non-contact relay that is arranged on a power line between a power source that operates the electromagnetic brake and the electromagnetic brake and opens and closes the power line A windmill braking control device comprising:

[0009] The present invention relates to at least one of the relative rotation between a pinion gear installed on the first structure and a ring gear installed on the second structure among the first structure and the second structure constituting the movable part of the windmill, and the rotation of a motor to which the pinion gear is attached. An electromagnetic brake for braking, A relay that opens or closes a power line between a power source that operates the electromagnetic brake and the electromagnetic brake at a response speed of 100 ms or less A windmill braking control device comprising:

[0010] In the windmill braking control device according to the present invention, the first structure may be a nacelle.

[0011] In the windmill braking control device according to the present invention, a speed reducer that is connected to the rotation shaft of the motor and outputs power obtained by reducing the rotation of the motor and increasing the torque to the pinion gear is further provided. The electromagnetic brake may brake the rotation of the pinion gear by braking the rotation of the rotation shaft of the motor.

[0012] In the wind turbine braking control device according to the present invention, a sensor that detects a load acting between the drive device having the motor, the speed reducer, and the pinion gear and the ring gear, a control unit that outputs a control signal for controlling the opening and closing of the power line to the relay according to the detected load may be further provided.

[0013] In the wind turbine braking control device according to the present invention, the sensor is a strain sensor that detects the load by detecting the strain of a bolt that fixes the drive device to the movable part, the control unit may output, as the control signal, a signal for instructing the release or closing of the power line when the detected load becomes equal to or greater than a threshold value.

[0014] In the wind turbine braking control device according to the present invention, the relay may have a photocoupler.

[0015] In the wind turbine braking control device according to the present invention, the relay may have a MOSFET.

[0016] In the wind turbine braking control device according to the present invention, the power supply is a three-phase power supply, and the relay may be a three-phase relay.

[0017] In the wind turbine braking control device according to the present invention, the power supply is a three-phase power supply, and the relay may be a single-phase relay.

[0018] In the wind turbine braking control device according to the present invention, a surge protection element disposed on the power line between the relay and the electromagnetic brake may be further provided.

[0019] The present invention is a wind turbine including the wind turbine braking control device.

Advantages of the Invention

[0020] According to the present invention, it is possible to suppress breakage of the ring gear due to a sudden change in the load acting on the ring gear of the wind turbine.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Modes for Carrying Out the Invention

[0022] Embodiments of the present invention will be described with reference to the drawings. In the drawings, for the convenience of illustration and easy understanding, there are parts where the scale, dimensional ratio, etc. are appropriately changed or exaggerated from those of the actual object.

[0023] (First Embodiment) FIG. 1 is a block diagram showing a windmill braking control device 200 according to the first embodiment. FIG. 2 is a perspective view showing a windmill 101 according to the first embodiment. FIG. 3 is a circuit diagram showing the windmill braking control device 200 according to the first embodiment.

[0024] The windmill braking control device 200 is a device that controls the braking of the windmill 101 by an electromagnetic brake 50 described later. As shown in FIG. 1, the windmill braking control device 200 includes an electromagnetic brake 50, a reed relay 210, a control unit 220, and a protection circuit 230.

[0025] The electromagnetic brake 50 is a device that brakes at least one of the relative rotation between a pinion gear 24a installed on a first structure among a first structure and a second structure constituting a movable part of the windmill 101 and a ring gear 107 installed on the second structure, and the rotation of a motor 23 to which the pinion gear 24a is attached. The term "brake" is interpreted in a broad sense and includes both holding the stopped state of a stopped object and stopping a moving object.

[0026] As shown in FIG. 2, the wind turbine 101 includes a tower 102, a nacelle 103, a rotor 104, and blades 105. The tower 102 extends vertically upward from the ground. The nacelle 103 is installed rotatably with respect to the tower 102 at the upper part of the tower 102. The rotation of the nacelle 103 is a yaw rotation with the longitudinal direction of the tower 102 as the rotation center. The nacelle 103 is driven by a driving device 10 having a motor 23. The driving device 10 of the nacelle 103 may further include a speed reducer that reduces the rotation of the motor 23 and outputs power with increased torque to the pinion gear 24a. Inside the nacelle 103, for example, devices necessary for wind power generation such as a power transmission shaft and a generator connected to the power transmission shaft are installed. The rotor 104 is connected to the power transmission shaft in the nacelle 103 and is rotatable with respect to the nacelle 103. A plurality of blades 105 (three in the example shown in FIG. 2) are provided. The plurality of blades 105 extend radially from the rotation axis of the rotor 104 with respect to the nacelle 103. These blades 105 are provided at equal angles around the rotation axis of the rotor 104.

[0027] Each blade 105 is rotatable in the pitch direction with respect to the rotor 104 about its longitudinal direction. The connection portion of each blade 105 to the rotor 104 is a movable part, and each blade 105 and the rotor 104 can rotate relative to each other. The blade 105 is rotationally driven by a driving device 10 having a motor 23. The driving device 10 of the blade 105 may further include a speed reducer that reduces the rotation of the motor 23 and outputs power with increased torque to the pinion gear 24a.

[0028] For example, the first structure of the wind turbine 101 is the nacelle 103, and the second structure is the tower 102. In this case, the electromagnetic brake 50 brakes at least one of the relative rotation between the pinion gear 24a installed on the nacelle 103 and the ring gear 107 installed on the tower 102 that meshes with the pinion gear 24a, and the rotation of the motor 23 to which the pinion gear 24a is attached.

[0029] The first structure of the wind turbine 101 may be the tower 102, and the second structure may be the nacelle 103. In this case, the electromagnetic brake 50 brakes at least one of the relative rotation between the pinion gear 24a installed on the tower 102 and the ring gear 107 installed on the nacelle 103 so as to mesh with the pinion gear 24a, and the rotation of the motor 23 to which the pinion gear 24a is attached.

[0030] The first structure of the wind turbine 101 may be the blade 105, and the second structure may be the rotor 104. In this case, the electromagnetic brake 50 brakes at least one of the relative rotation between the pinion gear 24a installed on the blade 105 and the ring gear 107 installed on the rotor 104 so as to mesh with the pinion gear 24a, and the rotation of the motor 23 to which the pinion gear 24a is attached.

[0031] The specific embodiment of the electromagnetic brake 50 is not particularly limited as long as it can brake at least one of the relative rotation between the pinion gear 24a installed on the first structure and the ring gear 107 installed on the second structure, and the rotation of the motor 23 to which the pinion gear 24a is attached. For example, the electromagnetic brake 50 may brake the rotation of the pinion gear 24a attached to the motor 23 by braking the rotation of the rotation shaft of the motor 23. In addition to this, for example, the electromagnetic brake 50 may brake the relative rotation between the pinion gear 24a installed on the first structure and the ring gear 107 installed on the second structure by applying a frictional force due to magnetic force between the first structure and the second structure.

[0032] As shown in FIG. 3, the electromagnetic brake 50 may be driven by a three-phase power supply. In the example shown in FIG. 3, the electromagnetic brake 50 has a coil 51 connected to the three-phase power supply. The coil 51 generates a magnetic force that releases the braking of the rotation of the motor 23, for example, by being supplied with power from the three-phase power supply. The coil 51 may generate a magnetic force that brakes the rotation of the motor 23 by being supplied with power from the three-phase power supply. The three-phase power supply may also be used for the rotational drive of the motor 23.

[0033] The non-contact relay 210 is disposed on the power line between the power source that operates the electromagnetic brake 50 and the electromagnetic brake 50, and is a device that opens and closes the power line without using mechanical contacts. The non-contact relay 210 is also called a semiconductor relay. In the example shown in FIG. 3, the non-contact relays 210 are disposed for each phase on the power line between the three-phase power source and the electromagnetic brake 50. That is, in the example shown in FIG. 3, three non-contact relays 210 are disposed. In the example shown in FIG. 3, the power source is three-phase, while the non-contact relay 210 is single-phase. Each non-contact relay 210 simultaneously opens and closes the corresponding power line according to a control signal from the control unit 220 described later. By providing three single-phase non-contact relays 210 that simultaneously open and close the power lines of each phase of the three-phase power source according to the control signal, the opening and closing control of the electromagnetic brake 50 can be quickly performed in response to a rapid change in the load acting between the drive device 10 and the ring gear 107. The non-contact relay 210 has, for example, a photocoupler. The non-contact relay 210 may have a MOSFET. Further, instead of disposing three single-phase non-contact relays 210, one three-phase non-contact relay having a three-phase circuit may be disposed. Thereby, the number of components can be reduced.

[0034] The control unit 220 is a device that controls the opening and closing of the power line by the non-contact relay 210 by outputting a control signal for controlling the opening and closing of the power line to the non-contact relay 210. When the load (i.e., the sensor output) detected by the sensor 4 that detects the load acting between the drive device 10 and the ring gear 107 becomes equal to or greater than the threshold value, the control unit 220 outputs an on signal for instructing the closing of the power line as a control signal to the non-contact relay 210. In response to the on signal, the non-contact relay 210 closes the power line. When the power line is closed, power is supplied from the power source to the electromagnetic brake 50. When power is supplied from the power source, the electromagnetic brake 50 switches from the locked state of braking the rotation of the motor 23 to the free state of releasing the braking of the rotation of the motor 23. The control unit 220 is composed of, for example, hardware such as a CPU or an electric circuit. A part of the control unit 220 may be composed of software.

[0035] In order to quickly switch the electromagnetic brake 50 to the free state in response to a sudden change in the load acting between the drive device 10 and the ring gear 107, the shorter the response speed of the non-contact relay 210 to the on signal, the more preferable. For example, the non-contact relay 210 closes the power line with a response speed of 100 ms or less. Preferably, the non-contact relay 210 closes the power line with a response speed of 10 ms or less. More preferably, the non-contact relay 210 closes the power line with a response speed of 1 ms or less.

[0036] The duration of the on signal is, for example, a short time on the order of ms. Therefore, the electromagnetic brake 50 temporarily (instantaneously) releases the braking of the rotation of the motor 23, and then brakes the rotation of the motor 23 again.

[0037] Note that the electromagnetic brake 50 may be configured to switch from the locked state to the free state when the power supply from the power source is cut off. In this case, when the load detected by the sensor 4 becomes equal to or greater than the threshold value, the control unit 220 may output an off signal for instructing the release of the power line as a control signal to the non-contact relay 210. In response to the off signal, the non-contact relay 210 releases the power line. When the power line is released, the power supply from the power source to the electromagnetic brake 50 is cut off. When the power supply from the power source is cut off, the electromagnetic brake 50 switches from the locked state to the free state. In this case, the shorter the response speed of the non-contact relay 210 to the off signal, the more preferable. For example, the non-contact relay 210 releases the power line with a response speed of 100 ms or less. Preferably, the non-contact relay 210 releases the power line with a response speed of 10 ms or less. More preferably, the non-contact relay 210 releases the power line with a response speed of 1 ms or less.

[0038] The protection circuit 230 is arranged on the power line between the non-contact relay 210 and the electromagnetic brake 50, and is a circuit that protects the wind turbine braking control device 200 from surges generated when the non-contact relay 210 is turned on and off. In the example shown in FIG. 3, the protection circuit 230 has three surge protection elements 231. The surge protection element 231 may be, for example, a varistor.

[0039] Next, an operation example of the wind turbine braking control device 200 according to the first embodiment will be described with reference to the flowcharts of FIGS. 4 and 5. FIG. 4 is a flowchart showing an operation example of the wind turbine braking control device 200 according to the first embodiment. FIG. 4 shows an operation example of the wind turbine braking control device 200 when the electromagnetic brake 50 is configured to switch from the locked state to the free state by power supply from the power source. FIG. 5 is a flowchart showing an operation example of the wind turbine braking control device 200 according to a modified example of the first embodiment. FIG. 5 shows an operation example of the wind turbine braking control device 200 when the electromagnetic brake 50 is configured to switch from the locked state to the free state by cutting off the power supply from the power source.

[0040] In the example shown in FIG. 4, the control unit 220 first acquires, from the sensor 4, a sensor output indicating the detection result of the load acting between the drive device 10 and the ring gear 107 (step S1).

[0041] After acquiring the sensor output, the control unit 220 determines whether the sensor output is equal to or greater than the threshold value (step S2).

[0042] When the sensor output is equal to or greater than the threshold value (step S2: Yes), the control unit 220 outputs an on signal to the non-contact relay 210 to close the power line between the power source and the electromagnetic brake 50 (step S3). As a result, power is supplied from the power source to the electromagnetic brake 50, and the electromagnetic brake 50 switches from the locked state to the free state.

[0043] On the other hand, when the sensor output is not equal to or greater than the threshold value (step S2: No), the control unit 220 repeats the acquisition of the sensor output (step S1).

[0044] In the example shown in FIG. 5, the control unit 220 first acquires, from the sensor 4, a sensor output indicating the detection result of the load acting between the drive device 10 and the ring gear 107 (step S11).

[0045] After acquiring the sensor output, the control unit 220 determines whether the sensor output is equal to or greater than a threshold value (step S12).

[0046] When the sensor output is equal to or greater than the threshold value (step S12: Yes), the control unit 220 outputs an off signal to the non-contact relay 210 to open the power line between the power supply and the electromagnetic brake 50 (step S13). As a result, the power supply to the electromagnetic brake 50 from the power supply is cut off, and the electromagnetic brake 50 switches from the locked state to the free state.

[0047] On the other hand, when the sensor output is not equal to or greater than the threshold value (step S12: No), the control unit 220 repeats the acquisition of the sensor output (step S11).

[0048] As described above, according to the first embodiment, when the load becomes excessive due to a rapid change in the load acting between the drive device 10 and the ring gear 107, the non-contact relay 210 can promptly close or open the power line between the power supply and the electromagnetic brake 50 in response to the sensor output becoming equal to or greater than the threshold value. By promptly closing or opening the power line, at least one of the braking of the relative rotation between the pinion gear 24a and the ring gear 107 and the braking of the rotation of the motor 23 can be promptly released. Thereby, breakage of the ring gear 107 due to the load can be suppressed.

[0049] (Second Embodiment) Next, a second embodiment showing a more specific application example of the present invention will be described. FIG. 6 is a cross-sectional view showing a part of the tower 102 and the nacelle 103 in the wind turbine 101 according to the second embodiment. FIG. 7 is a plan view showing the arrangement of the drive device 10 in the movable part in the wind turbine 101 according to the second embodiment. FIG. 8 is a side view of the drive device 10 including a partial cross-section in the wind turbine 101 according to the second embodiment. FIG. 9 is a side view of the installation part of the drive device 10 including a partial cross-section in the wind turbine 101 according to the second embodiment. FIG. 10 is a cross-sectional view showing the electromagnetic brake 50 in the wind turbine braking control device 200 according to the second embodiment.

[0050] The drive device 10 can drive the nacelle 103 rotatably installed with respect to the tower 102 of the wind turbine 101. Alternatively, the drive device 10 can drive the blade 105 swingably installed in the pitch direction with respect to the rotor 104 attached to the nacelle 103. That is, the drive device 10 can be used as a yaw drive device that performs yaw drive to rotate the nacelle 103 with respect to the tower 102, or can also be used as a pitch drive device that performs pitch drive to rotate the shaft portion of the blade 105 with respect to the rotor 104. In the following description, the case where the drive device 10 is used as a yaw drive device will be exemplified, but the present invention can be similarly applied to the case where the drive device 10 is used as a pitch drive device.

[0051] As shown in FIG. 6, the nacelle 103 is rotatably installed with respect to the upper part of the tower 102 via a bearing 106 provided at its bottom 103a. A ring gear 107 having internal teeth formed on its inner circumference is fixed to the upper part of the tower 102. The teeth of the ring gear 107 are not limited to the internal teeth provided on its inner circumference, and may be external teeth provided on its outer circumference. In each drawing, the illustration of each tooth of the ring gear 107 is omitted.

[0052] As shown in FIG. 7, the ring gear 107 is formed in a circumferential shape and has a central axis Cm. The nacelle 103 rotates about the central axis Cm of the ring gear 107. In the illustrated example, the central axis Cm of the ring gear 107 coincides with the longitudinal direction of the tower 102. Hereinafter, the direction parallel to the central axis Cm of the ring gear 107 is also simply referred to as the "axial direction dl".

[0053] In the illustrated wind turbine 101, as shown in FIG. 7, a pair of wind turbine drive systems 5 arranged rotationally symmetrically about the central axis Cm of the ring gear 107 are provided. Each wind turbine drive system 5 includes three drive devices 10. A total of six drive device bodies 20 included in the pair of wind turbine drive systems 5 are arranged along a circumference cl1 (see FIG. 7) about the central axis Cm of the ring gear 107. The three drive devices 10 included in each wind turbine drive system 5 are arranged at regular intervals along the circumference cl1.

[0054] As shown in FIGS. 6 and 7, the drive device 10 is provided in the nacelle 103 among the relatively rotationally movable nacelle 103 (first structure) and tower 102 (second structure).

[0055] As shown in FIGS. 8 and 9, each drive device 10 includes a drive device body 20 fixed to the nacelle 103 and a strain sensor 40 that detects the strain of a bolt 30a that fixes the drive device body 20 to the nacelle 103.

[0056] The drive unit main body 20 includes a motor 23, a speed reducer 25, and a pinion gear 24a. The motor 23 has a motor drive unit 48 that outputs power (i.e., rotational force) from a drive shaft 48a (i.e., a rotating shaft) when power is supplied from a power source, and an electromagnetic brake 50 that brakes the rotation of the drive shaft 48a. The speed reducer 25 is connected to the drive shaft 48a and the output shaft 24 of the motor 23. The speed reducer 25 reduces the rotation of the motor 23 input from the drive shaft 48a and outputs the power with increased torque to the output shaft 24. The pinion gear 24a is provided on the output shaft 24 connected to the speed reducer 25. The pinion gear 24a meshes with the teeth of a ring gear 107 provided on the tower 102. The pinion gear 24a transmits the power with increased torque by the speed reducer 25 to the ring gear 107, and thereby moves while rotating along the inner circumferential direction of the ring gear 107. As a result, the drive unit main body 20 having the pinion gear 24a moves along the inner circumferential direction of the ring gear 107, and the nacelle 103 to which the drive unit main body 20 is fixed pivots around the central axis Cm of the ring gear 107.

[0057] By driving each drive device 10 having such a configuration, the nacelle 103 (the first structure), which is one of the movable parts of the wind turbine 101, can be rotated with respect to the tower 102 (the second structure), which is the other movable part of the wind turbine 101. In particular, by operating a plurality of drive devices 10 included in the above-described wind turbine drive system 5 synchronously, a driving force of sufficient magnitude is ensured, and the heavy nacelle 103 can be appropriately rotated with respect to the tower 102.

[0058] More specifically, as shown in FIG. 9, the drive device 10 is fixed to the nacelle 103 via a fastener 30 that is disposed so as to pass through a through hole 22a formed in the flange 22 of the drive device main body 20. The fastener 30 has a bolt 30a and a nut 30b. The strain sensor 40 is fixed to the nacelle 103 using a jig 49. The strain sensor 40 detects the load acting between the drive device 10 having the motor 23, the speed reducer 25, and the pinion gear 24a and the ring gear 107 by detecting the strain of the bolt 30a. That is, the strain sensor 40 is a specific application example of the sensor 4 described in the first embodiment. As the mounting position of the strain sensor 40, a location where disturbances other than the load between the pinion gear 24a and the ring gear 107 do not act or act with difficulty is preferable. Specifically, for example, the case 21 is more preferable.

[0059] As shown in FIG. 8, the output shaft 24 of the drive device 10 is rotatably held within the case 21. The motor 23 is fixed to the upper part of the case 21. The speed reducer 25 is housed within the case 21. The specific form of the speed reducer 25 is not particularly limited as long as it is configured to output power with the rotation of the motor 23 decelerated and the torque increased. For example, an eccentric oscillating gear type speed reduction mechanism, a planetary gear type speed reduction mechanism, or a speed reduction mechanism in which an eccentric oscillating gear type and a planetary gear type are combined can be adopted for the speed reducer 25.

[0060] The end of the output shaft 24 on the side away from the speed reducer 25 extends from the case 21, and a pinion gear 24a is formed on this extended portion of the output shaft 24. As shown in FIGS. 6 and 9, the output shaft 24 passes through a through hole 103b formed in the bottom 103a of the nacelle 103, whereby the pinion gear 24a can mesh with the ring gear 107. The pinion gear 24a has external teeth that mesh with the internal teeth of the ring gear 107. The drive device 10 has a longitudinal axis that coincides with the rotational axis Cr of the output shaft 24. In a state where the drive device 10 is fixed to the nacelle 103, the rotational axis Cr of the output shaft 24 is parallel to the axial direction dl of the windmill 101.

[0061] As shown in FIGS. 8 and 9, the case 21 is formed in a cylindrical shape and is arranged such that its longitudinal axis is located on the rotation axis Cr. Both ends of the case 21 along the rotation axis Cr are open. The pinion gear 24a of the output shaft 24 is exposed from the opening of the case 21 on the tower 102 side. A motor 23 is attached to the opening of the case 21 on the side opposite to the tower 102. Further, the case 21 has a flange 22. In the example shown in FIG. 7, the flange 22 is formed in an annular shape along a circumference cl3 centered on the rotation axis Cr of the output shaft 24. As shown in FIGS. 8 and 9, the flange 22 is formed with the through holes 22a described above so as to extend in the axial direction dl. A large number of the through holes 22a are formed on a circumference centered on the rotation axis Cr of the output shaft 24, and 12 through holes 22a are formed in the illustrated example. And the fastener 30 passes through the through hole 22a formed in the flange 22 of the drive device main body 20 and penetrates the flange 22. In the example shown in FIG. 9, the bolt 30a penetrates the flange 22 of the drive device main body 20 and the bottom 103a of the nacelle 103. The nut 30b engages with the bolt 30a from the side of the nacelle 103. The fastener 30 constituted by the combination of the bolt 30a and the nut 30b is provided for each through hole 22a of the drive device main body 20. In the illustrated example, each drive device main body 20 is attached to the nacelle 103 at 12 locations by 12 fasteners 30.

[0062] Note that the fastener 30 is not limited to the illustrated example, and instead of using the nut 30b, a female thread that can be screwed with the male thread of the bolt 30a may be formed in the through hole of the nacelle 103. In this case, the fastener 30 is constituted by the bolt 30a, and the male thread of the bolt 30a engages with the female thread of the through hole of the nacelle 103, so that the drive device main body 20 can be fixed to the nacelle 103.

[0063] The strain sensor 40 is electrically connected to the control unit 220 (see FIG. 1) described in the first embodiment. The output of the strain sensor 40 indicating the detection result of the strain of the bolt 30a is input to the control unit 220 as an electrical signal. The control unit 220 controls the braking of the rotation of the motor 23 by the electromagnetic brake 50 based on the output of the strain sensor 40.

[0064] For example, the electromagnetic brake 50 may be configured as shown in FIG. 10. In the example shown in FIG. 10, the electromagnetic brake 50 is attached to the upper end portion on the side opposite to the reduction unit 25 of the cover 72 of the motor drive unit 48. The electromagnetic brake 50 includes a housing 50a, a friction plate 56, an armature 57, an elastic member 55, an electromagnet 53, and a first friction plate connecting portion 77.

[0065] The housing 50a is a structure that houses the friction plate 56, the armature 57, the elastic member 55, the electromagnet 53, and the first friction plate connecting portion 77. The housing 50a is fixed to the cover 72 of the motor drive unit 48.

[0066] The friction plate 56 is connected to the drive shaft 48a of the motor drive unit 48 via the first friction plate connecting portion 77. The upper end portion of the drive shaft 48a is disposed in a state of passing through the through hole of the friction plate 56.

[0067] The first friction plate connecting portion 77 has a spline shaft 77a and a slide shaft 77b. The spline shaft 77a is fixed to the outer periphery of the upper end portion of the drive shaft 48a by key coupling with a key member (not shown) and engagement with a stopper ring 77c. The slide shaft 77b is attached to the spline shaft 77a so as to be slidable in the axial direction. The first friction plate connecting portion 77 is provided with a spring mechanism (not shown) for positioning the axial position of the slide shaft 77b with respect to the spline shaft 77a at a predetermined position. The inner periphery of the friction plate 56 is fixed to the edge portion of the outer periphery of the flange-like portion of the slide shaft 77b, and the friction plate 56 is integrally coupled with the slide shaft 77b.

[0068] In the electromagnetic brake 50 having the above configuration, when the drive shaft 48a rotates, the spline shaft 77a, the slide shaft 77b, and the friction plate 56 also rotate together with the drive shaft 48a. In a state where the electromagnet 53 is excited, the slide shaft 77b and the friction plate 56, which are held so as to be axially slidable with respect to the drive shaft 48a and the spline shaft 77a, are positioned at predetermined positions in the axial direction of the spline shaft 77a by a spring mechanism. The friction plate 56 disposed at this predetermined position is separated from the armature 57 and the friction plate 58 described later.

[0069] The armature 57 is provided so as to be able to contact the friction plate 56. By contacting the friction plate 56, the armature 57 generates a braking force that brakes the rotation of the drive shaft 48a.

[0070] A friction plate 58 is provided at a location on the upper end portion of the cover 72 of the motor drive unit 48 that faces the friction plate 56. The friction plate 58 is installed at a position where it can contact the friction plate 56.

[0071] The elastic member 55 is held by the electromagnet body 53a of the electromagnet 53 described later. The elastic member 55 presses the armature 57 from the electromagnet 53 side toward the friction plate 56 side. In the example shown in FIG. 8, the elastic members 55 are arranged circumferentially in two arrays on the inner peripheral side and the outer peripheral side in a concentric circle centered on the drive shaft 48a in the electromagnet body 53a. Note that the above-described arrangement form of the elastic member 55 is merely an example, and the elastic member 55 may take other arrangement forms.

[0072] The electromagnet 53 includes an electromagnet body 53a and a coil 51, and separates the armature 57 from the friction plate 56 by attracting the armature 57 by magnetic force.

[0073] The electromagnet body 53a is fixed to the housing 51 at the upper end on the side opposite to the side facing the armature 57. The electromagnet body 53a is provided with a plurality of elastic member holding holes 53c that open toward the armature 57, and an elastic member 55 is disposed in each of these elastic member holding holes 53c. The coil 51 is installed inside the electromagnet body 53a.

[0074] When the braking of the rotation of the drive shaft 48a by the electromagnetic brake 50 is released, power (that is, current) is supplied from the power source to the coil 51 in response to the on-signal of the control unit 220, and the electromagnet 53 is energized. When the electromagnet 53 is energized and excited, the armature 57 is attracted to the coil 51 by the magnetic force generated in the electromagnet 53. At this time, the armature 57 is attracted to the electromagnet 53 against the elastic force (spring force) of the elastic member 55. As a result, the armature 57 is separated from the friction plate 56, and the braking of the rotation of the drive shaft 48a is released. Therefore, in the state where the electromagnet 53 is excited and the braking of the rotation of the drive shaft 48a is released, the armature 57 is in contact with the electromagnet body 53a.

[0075] On the other hand, when the braking of the rotation of the drive shaft 48a by the electromagnetic brake 50 is performed, the supply of power from the power source to the coil 51 is cut off because the on-signal of the control unit 2220 is not output. When the supply of power is cut off, the electromagnet 53 is demagnetized. When the electromagnet 53 is demagnetized, the armature 57 is pressed toward the friction plate 56 by the elastic force of the elastic member 55, and the armature 57 comes into contact with the friction plate 56. As a result, a frictional force is generated between the armature 57 and the friction plate 56, and the rotation of the drive shaft 48a is braked. Note that FIG. 10 shows a state where the electromagnet 53 is demagnetized and the rotation of the drive shaft 48a is braked.

[0076] Also, in a state where the electromagnet 53 is demagnetized and the drive shaft 48a is braked, the friction plate 56 is also in contact with the friction plate 58 by the elastic force acting from the armature 57. Therefore, when the electromagnet 53 is demagnetized, the friction plate 56 is sandwiched between the armature 57 and the friction plate 58 by the elastic force from the elastic member 55. As a result, the rotation of the drive shaft 48a is very strongly braked by the frictional force generated between the armature 57 and the friction plate 56 and the frictional force generated between the friction plate 56 and the friction plate 58.

[0077] According to the second embodiment, by braking the rotation of the drive shaft 48a upstream of the speed reducer 25 where the torque is smaller than that of the output shaft 24 by the electromagnetic brake 50, the drive shaft 48a can be appropriately braked with a small braking force by the electromagnetic brake 50.

[0078] Aspects of the present invention are not limited to the individual embodiments described above, but also include various modifications that can be conceived by those skilled in the art, and the effects of the present invention are not limited to the content described above. That is, various additions, changes, and partial deletions are possible without departing from the conceptual ideas and spirits of the present invention derived from the content defined in the claims and their equivalents.

[0079] Also, it is possible to combine or replace a part of the configurations described in the embodiments including the above-described modifications. Furthermore, it is possible to apply only a part of the configurations described in the embodiments including the above-described modifications. In these cases, in addition to what is explicitly stated in this specification, they have unique configurations derived from each configuration.

Description of Reference Numerals

[0080] 101 Windmill 102 Tower 103 Nacelle 24a Pinion Gear 50 Electromagnetic Brake 107 Ring Gear 210 Reed Relay

Claims

1. A wind turbine braking control device, an electromagnetic brake that brakes the rotation of a motor to which a pinion gear attached to the first structure of the first and second structures constituting the movable part of the wind turbine is attached; a non-contact relay that is disposed on a power line between a power source that operates the electromagnetic brake and the electromagnetic brake and opens and closes the power line; and comprising: the non-contact relay opens or closes the power line at a response speed of 100 ms or less; the first structure is a nacelle; the wind turbine braking control device controls the braking of the electromagnetic brakes provided in each of a plurality of drive devices having the pinion gear and the motor; the non-contact relay is a wind turbine braking control device that opens or closes the power line when a load acting between the drive device and a ring gear installed on the second structure becomes equal to or greater than a threshold value.

2. further comprising a speed reducer connected to the rotation shaft of the motor, the speed reducer reducing the rotation of the motor and increasing the torque and outputting the power to the pinion gear; the electromagnetic brake brakes the rotation of the pinion gear by braking the rotation of the rotation shaft of the motor, the wind turbine braking control device according to claim 1.

3. a sensor that detects the load acting between the drive device having the motor, the speed reducer, and the pinion gear and the ring gear; a control unit that outputs a control signal for controlling the opening and closing of the power line to the relay according to the detected load; the wind turbine braking control device according to claim 2, further comprising:

4. the sensor is a strain sensor that detects the load by detecting the strain of a bolt that fixes the drive device to the movable part; When the detected load is equal to or greater than the threshold value, the control unit outputs a signal for instructing opening or closing of the power line as the control signal. The windmill braking control device according to claim 3.

5. The windmill braking control device according to any one of claims 1 to 4, wherein the relay has a photocoupler.

6. The windmill braking control device according to any one of claims 1 to 5, wherein the relay has a MOSFET.

7. The windmill braking control device according to any one of claims 1 to 6, wherein the power supply is a three-phase power supply and the relay is a three-phase relay.

8. The windmill braking control device according to any one of claims 1 to 6, wherein the power supply is a three-phase power supply and the relay is a single-phase relay.

9. The windmill braking control device according to any one of claims 1 to 8, further comprising a surge protection element disposed on the power line between the relay and the electromagnetic brake.

10. A windmill comprising the windmill braking control device according to any one of claims 1 to 9.

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