Wind turbine overspeed protection device, detection method and wind turbine

Abstract

The embodiment of the present invention discloses an overspeed protection device for a wind turbine generator set, a detection method and a wind turbine generator set. The overspeed protection device for a wind turbine generator set includes: an overspeed trigger assembly and at least two clutches; the clutch is arranged between the pitch motor and the pitch gearbox of the wind turbine generator set, and the clutch is used to transmit or cut off the power input from the pitch motor to the pitch gearbox; the first end of the overspeed trigger assembly is fixed to the rotation center of the hub, and the second end of the overspeed trigger assembly is elastically retractable relative to the first end; when the hub rotates at an overspeed, the second end of the overspeed trigger assembly extends out to hit the clutch to cut off the power input from the pitch motor to the pitch gearbox. This solution is not affected by electrical signals and electrical circuits, and can reliably protect the wind turbine generator set from overspeed in the extreme case where all electrical circuits fail, thereby greatly enhancing the reliability of overspeed protection of the wind turbine generator set.

Description

Technical Field

[0001] Embodiments of the present invention relate to the technical field of wind power generation, and in particular, to an overspeed protection device for a wind turbine generator, a detection method, and a wind turbine generator. Background Art

[0002] Overspeed protection is one of the important protections for wind turbine generators. The existing overspeed protections of wind turbine generators rely on electrical signals and electrical circuits, that is, electrical overspeed protection. Currently, in the case where overspeed may occur, such as power loss on the grid side, the probability of electrical signal and electrical circuit failures will increase. And the action command of overspeed protection needs to be executed by the pitch system, but the execution of the pitch system depends on slip rings and batteries (or supercapacitors), and slip rings and batteries (or supercapacitors) are components with relatively high failure rates. Therefore, the failure rate of overspeed protection actions will be further increased. Once the electrical overspeed protection fails to act, it often brings serious consequences such as the destruction of the machine and the collapse of the tower. Summary of the Invention

[0003] Embodiments of the present invention provide an overspeed protection device for a wind turbine generator, a detection method, and a wind turbine generator, which are not affected by electrical signals and electrical circuits, and can still reliably protect the wind turbine generator from overspeed in extreme cases where all electrical circuits fail.

[0004] In a first aspect, embodiments of the present invention provide an overspeed protection device for a wind turbine generator, which includes: an overspeed trigger assembly and at least two clutches;

[0005] The clutch is disposed between the pitch motor and the pitch gearbox of the wind turbine generator, and the clutch is used to transmit or cut off the power input from the pitch motor to the pitch gearbox;

[0006] The first end of the overspeed trigger assembly is fixed at the hub rotation center position, and the second end of the overspeed trigger assembly is elastically telescopic relative to the first end; when the hub rotation speed exceeds the limit, the second end of the overspeed trigger assembly extends to hit the clutch to cut off the power input from the pitch motor to the pitch gearbox.

[0007] Optionally, the overspeed trigger assembly includes at least two first springs and at least two impact blocks corresponding to the first springs one by one;

[0008] The first end of each first spring serves as the first end of the overspeed trigger assembly, the second end of the first spring is connected to the corresponding impact block, and the impact block serves as the second end of the overspeed trigger assembly; when the hub rotation speed exceeds the limit, the impact block hits the clutch.

[0009] Optionally, the overspeed trigger assembly further includes at least two round tubes;

[0010] The inner diameter of the circular tube is larger than the diameter of the first spring; each of the first springs is nested within one of the circular tubes, and the circular tubes are used to restrict the expansion and contraction direction of the first springs.

[0011] Optionally, the clutch includes a clutch body and a clutch handle;

[0012] The clutch body is connected to the clutch body, and the impact block impacts the clutch handle so that the clutch body switches from a fitting state to a separated state, thereby cutting off the power input from the pitch motor to the pitch gearbox.

[0013] Optionally, the number of the clutches is equal to the number of the first springs;

[0014] The clutch handles are connected by a linkage mechanism; when the rotational speed of the hub exceeds the speed limit, any one of the impact blocks impacts the clutch handle, driving the other clutch handles and the clutch bodies connected thereto to switch from a fitting state to a separated state.

[0015] Optionally, the clutch further includes a locking and resetting assembly;

[0016] The locking and resetting assembly includes a pin, a second spring, and a reset electromagnet; one end of the pin contacts the clutch handle, the other end of the pin is connected to one end of the second spring in a compressed state, and the other end of the second spring is fixed;

[0017] When the impact block impacts the clutch handle, the pin pops out so that the clutch handle and the clutch body are in a separated state;

[0018] When the reset electromagnet is energized, the reset electromagnet generates an electromagnetic force to pull back the pin so that the clutch handle and the clutch body resume the fitting state to transmit the power input from the pitch motor to the pitch gearbox.

[0019] Optionally, the overspeed protection device of the wind turbine generator further includes a pitch device;

[0020] The pitch device includes a blade bearing and a third spring;

[0021] One end of the third spring is connected to the outer ring of the blade bearing, and the other end of the third spring is connected to the inner ring of the blade bearing;

[0022] When the clutch cuts off the power input from the pitch motor to the pitch gearbox, the third spring is used to pull the blade bearing back to the feathering state to decelerate the hub.

[0023] Optionally, the overspeed protection device of the wind turbine generator further includes a detection device;

[0024] The detection device is used to simulate the overspeed state of the hub rotation speed and detect whether the second end of the overspeed trigger component extends out to impact the clutch.

[0025] Optionally, the detection device includes a detection electromagnet and a rotational speed sensor;

[0026] The detection electromagnet is used to generate a suction force on the second end of the overspeed trigger component to simulate the centrifugal force received by the second end of the overspeed trigger component; the rotational speed sensor is used to detect the hub rotation speed.

[0027] In a second aspect, an embodiment of the present invention further provides a detection method for an overspeed protection device of a wind turbine generator. The overspeed protection device of the wind turbine generator includes: an overspeed trigger component and at least two clutches;

[0028] The clutch is arranged between the pitch motor and the pitch gearbox of the wind turbine generator, and the clutch is used to transmit or cut off the power input from the pitch motor to the pitch gearbox; the first end of the overspeed trigger component is fixed at the hub rotation center position, and the second end of the overspeed trigger component is elastically telescopic relative to the first end;

[0029] The overspeed protection device of the wind turbine generator further includes: a detection device;

[0030] The detection method for the overspeed protection device of the wind turbine generator includes:

[0031] Obtain the current hub rotation speed, the relationship between the suction force generated by the detection device and its energization current when the second end of the overspeed trigger component impacts the clutch, and the static suction force; wherein, when the hub is stationary and the second end of the overspeed trigger component impacts the clutch, the suction force of the detection device on the second end of the overspeed trigger component is defined as the static suction force;

[0032] According to the hub rotation speed, the relationship between the suction force generated by the detection device and its energization current when the second end of the overspeed trigger component impacts the clutch, and the static suction force, calculate the energization current of the current detection device and record it as the threshold current;

[0033] Provide a current greater than or equal to the threshold current to the detection device to verify whether the second end of the overspeed trigger component extends out to impact the clutch, and whether the blades of the wind turbine generator return to the feathering position within a preset time, so as to determine whether the overspeed protection device of the wind turbine generator is qualified.

[0034] Optionally, the detection device includes a detection electromagnet and a rotational speed sensor;

[0035] A detection method for an overspeed protection device of a wind turbine generator set includes:

[0036] Obtain the rotational speed of the hub currently detected by the rotational speed sensor, the relationship between the attraction force generated by the detection electromagnet when the second end of the overspeed trigger component impacts the clutch and its energizing current, and the static attraction force; wherein, when the hub is stationary and the second end of the overspeed trigger component impacts the clutch, the attraction force of the detection electromagnet on the second end of the overspeed trigger component is defined as the static attraction force;

[0037] According to the rotational speed of the hub, the relationship between the attraction force generated by the detection electromagnet when the second end of the overspeed trigger component impacts the clutch and its energizing current, and the static attraction force, calculate the energizing current of the current detection electromagnet, and record it as the threshold current;

[0038] Provide a current greater than or equal to the threshold current to the detection electromagnet, verify whether the second end of the overspeed trigger component extends to impact the clutch, and whether the blades of the wind turbine generator set return to the feathering position within a preset time, so as to determine whether the overspeed protection device of the wind turbine generator set is qualified.

[0039] Optionally, the overspeed trigger component includes at least two first springs and at least two impact blocks corresponding to the first springs one by one; the first end of each first spring serves as the first end of the overspeed trigger component, the second end of the first spring is connected to the corresponding impact block, and the impact block serves as the second end of the overspeed trigger component;

[0040] The method for calculating the energizing current of the current detection electromagnet includes:

[0041] Calculate the centrifugal force received by the impact block according to the rotational speed of the hub;

[0042] Calculate the attraction force that the current detection electromagnet should generate on the impact block according to the static attraction force and the centrifugal force, and record it as the threshold attraction force;

[0043] Calculate the threshold current according to the relationship between the attraction force generated by the detection electromagnet when the second end of the overspeed trigger component impacts the clutch and its energizing current and the threshold attraction force.

[0044] Optionally, before obtaining the current rotational speed of the hub, the relationship between the attraction force generated by the detection device and its energizing current, and the static attraction force, it further includes:

[0045] Set the mechanical overspeed threshold to be greater than the electrical overspeed threshold;

[0046] Before supplying a current greater than the threshold current to the detection electromagnet, it further includes:

[0047] Disable the electrical overspeed protection.

[0048] In a third aspect, an embodiment of the present invention further provides a wind turbine generator, which includes the wind turbine generator overspeed protection device proposed in any of the above embodiments.

[0049] The wind turbine generator overspeed protection device provided by the embodiment of the present invention includes a clutch that can cut off the power source of the pitch gearbox and an overspeed trigger assembly that can monitor the rotational speed of the wind turbine generator hub in real time. Among them, when the rotational speed of the hub is overspeed, the second end of the overspeed trigger assembly extends out and impacts the clutch, so that the clutch cuts off the power input from the pitch motor to the pitch gearbox, thereby reducing the speed of the hub. The designed wind turbine generator overspeed protection device in this case is a mechanical protection device, which is not affected by electrical signals and electrical circuits, that is, in the extreme case where all electrical circuits fail, the designed wind turbine generator overspeed protection device can still operate reliably, and can timely cut off the power input from the pitch motor to the pitch gearbox through the clutch to achieve the purpose of reducing the speed of the hub. In summary, the designed wind turbine generator overspeed protection device in this solution greatly enhances the reliability of the wind turbine generator overspeed protection. Description of the Drawings

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0051] Figure 1 It is a schematic structural diagram of a wind turbine generator overspeed protection device provided by an embodiment of the present invention;

[0052] Figure 2 It is a schematic structural diagram of an overspeed trigger assembly provided by an embodiment of the present invention;

[0053] Figure 3 It is a perspective schematic structural diagram of an overspeed trigger assembly provided by an embodiment of the present invention;

[0054] Figure 4 It is a schematic structural diagram of a clutch in a engaged state provided by an embodiment of the present invention;

[0055] Figure 5Schematic structural diagram of a clutch in a disengaged state provided by an embodiment of the present invention;

[0056] Figure 6 Partial schematic structural diagram of an overspeed protection device for a wind turbine provided by an embodiment of the present invention;

[0057] Figure 7 Schematic structural diagram of a pitch control device provided by an embodiment of the present invention;

[0058] Figure 8 Partial schematic structural diagram of another overspeed protection device for a wind turbine provided by an embodiment of the present invention;

[0059] Figure 9 Schematic flow diagram of a detection method for an overspeed protection device of a wind turbine provided by an embodiment of the present invention;

[0060] Figure 10 Schematic flow diagram of another detection method for an overspeed protection device of a wind turbine provided by an embodiment of the present invention;

[0061] Figure 11 Schematic flow diagram of a method for calculating the energizing current of a current detection electromagnet provided by an embodiment of the present invention;

[0062] Figure 12 Schematic flow diagram of yet another detection method for an overspeed protection device of a wind turbine provided by an embodiment of the present invention;

[0063] Figure 13 Schematic structural diagram of a wind turbine provided by an embodiment of the present invention. Detailed implementation manners

[0064] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0065] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of the present invention are used to distinguish similar objects and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0066] Among them, with the increasing popularity of new energy power generation, people's demand for the capacity of wind turbine generators is increasing day by day. At present, the unit price and maintenance cost of large-capacity wind turbine generators are relatively high. Therefore, once the electric overspeed protection fails, it will lead to serious consequences such as the destruction of the machine and the collapse of the tower, resulting in huge economic losses. In this regard, this solution adds an overspeed protection device for wind turbine generators on the basis of the original electric overspeed protection of wind turbine generators to achieve double overspeed protection for wind turbine generators.

[0067] It should be noted that: the number of clutches is determined by the number of wind turbine blades. At present, the number of wind turbine blades on the market is three. In the following embodiments, the overspeed protection device for wind turbine generators designed in this solution is described with the number of clutches being three, but the number of clutches being three is not a limitation on the present invention.

[0068] Figure 1 The structural schematic diagram of an overspeed protection device for a wind turbine generator provided by an embodiment of the present invention is as Figure 1 shown. The overspeed protection device for a wind turbine generator provided by an embodiment of the present invention includes: an overspeed trigger assembly 110 and at least two clutches 120. The clutch 120 is arranged between the pitch motor 210 and the pitch gearbox 220 of the wind turbine generator. The clutch 120 is used to transmit or cut off the power input from the pitch motor 210 to the pitch gearbox 220. The first end M1 of the overspeed trigger assembly 110 is fixed at the hub rotation center position O, and the second end M2 of the overspeed trigger assembly 110 is elastically telescopic relative to the first end M1. When the hub rotation speed exceeds the speed, the second end M2 of the overspeed trigger assembly 110 extends out to impact the clutch 120 to cut off the power input from the pitch motor 210 to the pitch gearbox 220.

[0069] Among them, the overspeed protection device of the wind turbine generator is a mechanical protection device. The clutch 120 is similar to a switch, and its driving part and driven part can be temporarily separated and gradually engaged. Therefore, the clutch 120 can engage or disconnect the power transmission. The clutch 120 is arranged between the pitch motor 210 and the pitch gearbox 220 of the wind turbine generator. Thus, the clutch 120 can transmit or cut off the power input from the pitch motor 210 to the pitch gearbox 220. Exemplarily, when the driving part of the clutch 120 is separated from its driven part, the power input from the pitch motor 210 to the pitch gearbox 220 can be cut off; when the driving part of the clutch 120 is engaged with its driven part, the power input from the pitch motor 210 to the pitch gearbox 220 can be transmitted.

[0070] The first end M1 of the overspeed trigger assembly 110 is fixed at the hub rotation center position O, and the second end M2 of the overspeed trigger assembly 110 is elastically telescopic relative to the first end M1. Therefore, the overspeed trigger assembly 110 can generate centrifugal force during the rotation driven by the hub. Specifically, the greater the rotation speed of the hub, the greater the centrifugal force generated by the second end M2 of the overspeed trigger assembly 110, and the greater the elongation distance of the second end M2 of the overspeed trigger assembly 110. Therefore, the rotation speed of the hub of the wind turbine generator can be monitored according to the elongation distance of the second end M2 of the overspeed trigger assembly 110.

[0071] The working principle of the overspeed protection device of the wind turbine generator is as follows: when the overspeed trigger assembly 110 rotates with the hub, the second end M2 of the overspeed trigger assembly 110 generates centrifugal force. At the same time, the telescopic length of the second end M2 of the overspeed trigger assembly 110 increases under the pull of the centrifugal force, that is, the distance from the hub rotation center position O increases. When the rotation speed of the hub is overspeed, the distance that the second end M2 of the overspeed trigger assembly 110 generates centrifugal force to move away from the hub rotation center position O is greater than or equal to the distance between the hub rotation center position O and the clutch 120. Obviously, at this time, the second end M2 of the overspeed trigger assembly 110 extends too long and will hit the clutch 120. After being hit, the driving part of the clutch 120 will be separated from the driven part, thereby cutting off the power input from the pitch motor 210 to the pitch gearbox 220.

[0072] The overspeed protection device for a wind turbine generator provided by an embodiment of the present invention includes a clutch 120 that can cut off the power source of the pitch gearbox 220 and an overspeed trigger assembly 110 that can monitor the rotational speed of the hub of the wind turbine generator in real time. Among them, when the rotational speed of the hub is overspeed, the second end M2 of the overspeed trigger assembly 110 extends to impact the clutch 120, so that the clutch 120 cuts off the power input from the pitch motor 210 to the pitch gearbox 220, thereby reducing the speed of the hub. The designed overspeed protection device for the wind turbine generator in this case is a mechanical protection device, which is not affected by electrical signals and electrical circuits. That is, in the extreme case where all electrical circuits fail, the designed overspeed protection device for the wind turbine generator can still operate reliably, and can timely cut off the power input from the pitch motor 210 to the pitch gearbox 220 through the clutch 120 to achieve the purpose of reducing the speed of the hub. In summary, the designed overspeed protection device for the wind turbine generator in this solution greatly enhances the reliability of the overspeed protection of the wind turbine generator.

[0073] Based on the above embodiments, Figure 2 is a schematic structural diagram of an overspeed trigger assembly provided by an embodiment of the present invention, as Figure 2 shown, the overspeed trigger assembly 110 includes at least two first springs 111 and at least two impact blocks 112 corresponding to the first springs 111 one by one; the first end of each first spring 111 is used as the first end M1 of the overspeed trigger assembly 110, the second end of the first spring 111 is connected to the corresponding impact block 112, and the impact block 112 is used as the second end M2 of the overspeed trigger assembly 110; when the rotational speed of the hub is overspeed, the impact block 112 impacts the clutch.

[0074] Specifically, when the first spring 111 is connected to the impact block 112 and rotates with the hub, the impact block 112 is always in force balance during the rotation with the hub, that is, the pulling force of the first spring 111 on the impact block 112 is equal in magnitude and opposite in direction to the centrifugal force generated by the rotation of the impact block 112. Among them, the pulling force of the spring is equal to the spring coefficient of the first spring 111 multiplied by the stretching length of the first spring 111. Thus, the greater the rotational speed of the impact block 112 with the hub, the greater the centrifugal force on the impact block 112, and the greater the stretching length of the first spring 111, that is, the greater the distance of the impact block 112 from the rotation center position O of the hub. When the rotational speed of the hub is overspeed, the centrifugal force generated by the impact block 112 causes the stretching length of the first spring 111 it pulls to be greater than or equal to the distance between the rotation center position O of the hub and the clutch. Obviously, at this time, the impact block 112 will impact the clutch, so that the clutch cuts off the power input from the pitch motor to the pitch gearbox, thereby achieving the deceleration of the hub.

[0075] Based on the above embodiments, Figure 3 is a perspective structural diagram of an overspeed trigger assembly provided by an embodiment of the present invention, asFigure 3 As shown, the overspeed trigger assembly 110 further includes at least two circular tubes 113; the inner diameter of the circular tube 113 is greater than the diameter of the first spring 111; each first spring 111 is nested within a circular tube 113, and the circular tube 113 is used to limit the telescopic direction of the first spring 111.

[0076] Wherein, each first spring 111 is nested inside a circular tube 113, and each circular tube 113 can limit the telescopic direction of the first spring 111 embedded therein, and prevent the first springs 111 from winding around each other, or prevent the first spring 111 from bending and winding itself. Thus, the certainty of the telescopic direction of the first spring 111 within the circular tube 113 as the hub rotates can be further ensured.

[0077] It should be noted that: the inner diameter of the circular tube 113 needs to be greater than the diameter of the first spring 111, but it is not infinitely large. The inner diameter of the circular tube 113 needs to be less than twice the diameter of the first spring 111. Preferably, the inner diameter of the circular tube 113 is only slightly larger than the diameter of the first spring 111.

[0078] Based on the above embodiments, Figure 4 is a schematic structural diagram of a clutch in a engaged state provided by an embodiment of the present invention. Figure 5 is a schematic structural diagram of a clutch in a disengaged state provided by an embodiment of the present invention. Refer to Figure 4 - Figure 5 , the clutch 120 includes a clutch main body 121 and a clutch handle 122; the clutch main body 121 is connected to the clutch 122 main body, and the impact block impacts the clutch handle 122 to switch the clutch main body 121 from the engaged state to the disengaged state, so as to cut off the power input from the pitch motor to the pitch gearbox.

[0079] Wherein, the handle of the clutch is the active part of the clutch 120, and the main body of the clutch is the driven part of the clutch 120. The handle of the clutch and the main body of the clutch can be temporarily separated or gradually engaged. Exemplarily, when the impact block impacts the clutch handle 122, the clutch handle 122 moves in the impact direction of the impact block, resulting in the separation of the clutch main body 121 from the clutch handle 122, so that the clutch main body 121 is switched from the engaged state to the disengaged state. At the same time, the clutch main body 121 will cut off the power input from the pitch motor to the pitch gearbox, thereby decelerating the hub.

[0080] Based on the above embodiments, optionally, the number of clutches is equal to the number of first springs; the clutch handles are connected by a linkage mechanism; when the rotational speed of the hub exceeds the speed, any impact block impacts the clutch handle, driving the remaining clutch handles and their connected clutch main bodies to switch from the engaged state to the disengaged state.

[0081] Among them, the number of each clutch is equal to that of the first spring, and each clutch is correspondingly provided with an impact block connected to a first spring. After each clutch handle is impacted by its corresponding impact block, the clutch body will switch from the fitting state to the separated state.

[0082] In addition, the clutch handles are connected by a linkage mechanism. When the rotational speed of the hub exceeds the speed limit, as long as one impact block impacts a clutch handle, the linkage mechanism can quickly drive the clutch bodies connected to the remaining clutch handles to switch from the fitting state to the separated state. Thus, the input power connected to the pitch gearbox for each blade can be cut off simultaneously, so as to adjust the pitch gearbox simultaneously and make the hub decelerate rapidly.

[0083] Based on the above embodiments, Figure 6 is a partial structural schematic diagram of an overspeed protection device for a wind turbine generator set provided by an embodiment of the present invention. As Figure 6 shown, the clutch 120 further includes a locking and resetting assembly 123; the locking and resetting assembly 123 includes a pin 1231, a second spring 1232, and a reset electromagnet 1233; one end of the pin 1231 contacts the clutch handle 122, the other end of the pin 1231 is connected to one end of the second spring 1232 in a compressed state, and the other end of the second spring 1232 is fixed; when the impact block 112 impacts the clutch handle 122, the pin 1231 pops out to make the clutch handle 122 and the clutch body 121 in a separated state; when the reset electromagnet 1233 is energized, the reset electromagnet 1233 generates an electromagnetic force to pull back the pin 1231 to make the clutch handle 122 and the clutch body 121 return to the fitting state to transmit the power input by the pitch motor 210 to the pitch gearbox 220.

[0084] Among them, the locking and resetting assembly can switch the clutch body 121 from the separated state to the fitting state, so as to restore the working state of the clutch body 121 to transmit the power input by the pitch motor 210 to the pitch gearbox 220.

[0085] Specifically, when the impact block 112 impacts the clutch handle 122, the clutch handle 122 will move in the impact direction of the impact block 112. At this time, the pin 1231 is separated from the clutch handle 122, and the pin 1231 pops out under the elastic force exerted by the second spring 1232 in the compressed state. At the same time, the second spring 1232 returns to the stretched state, and the position where the pin 1231 pops out is below the clutch handle 122, making the clutch handle 122 and the clutch body 121 in a separated state, so that the clutch body 121 cuts off the power input by the pitch motor 210 to the pitch gearbox 220.

[0086] When the reset electromagnet 1233 is energized, the reset electromagnet 1233 generates an electromagnetic force to pull the pin 1231 back from under the clutch handle 122, and the second spring 1232 also returns to the compressed state under the magnetic force generated by the reset electromagnet 1233. At the same time, the clutch handle 122 and the clutch body 121 return to the fitting state, so that the clutch body 121 transmits the power input by the pitch motor 210 to the pitch gearbox 220.

[0087] Based on the above embodiments, Figure 7 The structure schematic diagram of a pitch device provided by an embodiment of the present invention is shown as Figure 7 The shown wind turbine overspeed protection device further includes a pitch device 130; the pitch device 130 includes a blade bearing 131 and a third spring 132; one end of the third spring 132 is connected to the outer ring 1311 of the blade bearing 131, and the other end of the third spring 132 is connected to the inner ring 1312 of the blade bearing 131; when the clutch cuts off the power input by the pitch motor to the pitch gearbox, the third spring 132 is used to pull the blade bearing 131 back to the feathering state to decelerate the hub.

[0088] Among them, when the clutch cuts off the power input by the pitch motor to the pitch gearbox, the pitch gearbox loses the power source and cannot overcome the pulling force of the third spring 132 to make the blade bearing 131 change from the feathering state to the unfeathering state. At this time, both ends of the third spring 132 will respectively pull the outer ring 1311 and the inner ring 1312 of the blade bearing 131, pulling the blade bearing 131 back to the feathering state to decelerate the hub.

[0089] When the clutch transmits the power input by the pitch motor to the pitch gearbox, after the pitch gearbox obtains the power source, the inner ring 1312 of the blade bearing 131 can rotate against the pulling force of the third spring 132, making the blade bearing 131 change from the feathering state to the unfeathering state, so that the blade drives the hub to accelerate under the push of the wind force.

[0090] Based on the above embodiments, Figure 8 The partial structure schematic diagram of another wind turbine overspeed protection device provided by an embodiment of the present invention is shown as Figure 8 As shown, the wind turbine overspeed protection device further includes a detection device 140; the detection device 140 is used to simulate the overspeed state of the hub rotation speed and detect whether the second end of the overspeed trigger component 110 extends out to hit the clutch 120.

[0091] Among them, the detection device 140 can simulate the centrifugal force generated by the rotation of the second end M2 of the overspeed trigger assembly 110 with the hub by the attraction of the electromagnet, so that the overspeed protection detection can be carried out at any rotational speed of the hub at any time. Thus, the detection by the detection device 140 can simulate the actual overspeed rotation condition of the hub, and there is actually no risk of overspeed rotation of the hub. Therefore, using the detection device 140 for detection improves the reliability and convenience of the overspeed rotation detection of the hub.

[0092] On the basis of the above embodiment, optionally, the detection device includes a detection electromagnet and a rotational speed sensor; the detection electromagnet is used to generate a suction force on the second end of the overspeed trigger assembly to simulate the centrifugal force received by the second end of the overspeed trigger assembly; the rotational speed sensor is used to detect the rotational speed of the hub.

[0093] Specifically, after the detection electromagnet is energized, it can generate a magnetic force, which can generate a suction force on the second end (impact block) of the overspeed trigger assembly. Among them, the magnitude of the suction force of the detection electromagnet on the impact block depends on the magnitude of the magnetic force generated by the electromagnet, and the magnitude of the magnetic force generated by the electromagnet depends on the magnitude of the energizing current of the detection electromagnet. It can be seen from this that the magnitude of the suction force of the detection electromagnet on the impact block depends on the magnitude of the energizing current of the detection electromagnet. The rotational speed sensor can detect the rotational speed of the hub, and the actual magnitude of the centrifugal force received by the impact block can be known according to the rotational speed of the hub.

[0094] When using the detection device and the rotational speed sensor to conduct an overspeed protection test on a rotating hub, the actual magnitude of the centrifugal force received by the impact block can be calculated according to the rotational speed of the hub detected by the rotational speed sensor. Thus, the magnitude of the centrifugal force difference between the actual centrifugal force received by the current impact block and the centrifugal force when the impact block impacts the clutch can be known. Among them, the centrifugal force difference between the actual centrifugal force received by the current impact block and the centrifugal force when the impact block impacts the clutch can be replaced by the attraction of the detection electromagnet energized on the impact block, so that the simulation detection of the overspeed rotation condition of the hub can be realized.

[0095] Figure 9 It is a schematic flow chart of a detection method for an overspeed protection device of a wind turbine generator provided by an embodiment of the present invention. This embodiment is applicable to the detection of the overspeed protection device of the wind turbine generator arbitrarily proposed in the above embodiment.

[0096] Among them, the overspeed protection device of the wind turbine generator includes: an overspeed trigger assembly and at least two clutches; the clutches are arranged between the pitch motor and the pitch gearbox of the wind turbine generator, and the clutches are used to transmit or cut off the power input from the pitch motor to the pitch gearbox; the first end of the overspeed trigger assembly is fixed at the hub rotation center position, and the second end of the overspeed trigger assembly is elastically telescopic relative to the first end; the overspeed protection device of the wind turbine generator further includes: a detection device.

[0097] Detection method for overspeed protection device of wind turbine generator, specifically including the following steps:

[0098] S310. Obtain the current hub rotation speed, the relationship between the attraction generated by the detection device when the second end of the overspeed trigger component impacts the clutch and its energizing current, and the static attraction; wherein, when the hub is stationary and the second end of the overspeed trigger component impacts the clutch, the attraction of the detection device to the second end of the overspeed trigger component is defined as the static attraction.

[0099] Among them, the relationship between the attraction generated by the detection device when the second end of the overspeed trigger component impacts the clutch and its energizing current, and the static attraction are obtained by pre-experiment detection and calculation. The static attraction is also the attraction of the detection device to the second end of the overspeed trigger component detected in advance by experiment when the hub is stationary and the second end of the overspeed trigger component impacts the clutch.

[0100] S320. Calculate the energizing current of the current detection device according to the hub rotation speed, the relationship between the attraction generated by the detection device when the second end of the overspeed trigger component impacts the clutch and its energizing current, and the static attraction, and record it as the threshold current.

[0101] Exemplarily, if the current hub rotation angular velocity is ω; then the centrifugal force F generated by the impact block ω is: F ω = mω 2 r. Wherein, m represents the mass of the impact block, and r represents the distance from the impact block to the rotation center when it impacts the clutch. The static attraction is F 1 .

[0102] The attraction F generated by the detection device is: F = F 1 - F ω . Substitute the attraction generated by the detection device into the relationship between the attraction generated by the detection device when the second end of the overspeed trigger component impacts the clutch and its energizing current, and the minimum current required to energize the detection device when the impact block hits the clutch can be obtained, that is, the threshold current.

[0103] S330. Provide a current greater than or equal to the threshold current to the detection device, verify whether the second end of the overspeed trigger component extends out to impact the clutch, and whether the blades of the wind turbine generator return to the feathering position within a preset time, so as to determine whether the overspeed protection device of the wind turbine generator is qualified.

[0104] Among them, if the second end of the overspeed trigger component extends to hit the clutch and the blades of the wind turbine return to the feathering position within a preset time, it indicates that the overspeed protection device of the wind turbine is qualified; if the second end of the overspeed trigger component does not extend to hit the clutch or the blades of the wind turbine do not return to the feathering position within the preset time, it indicates that the overspeed protection device of the wind turbine is unqualified.

[0105] It should be noted that the preset time is a pre-set time and needs to be configured according to the actual wind turbine.

[0106] The detection method provided by the embodiment of the present invention is implemented based on the overspeed protection device of the wind turbine provided by any embodiment of the present invention. Therefore, the detection method provided by the embodiment of the present invention also has the beneficial effects described in the above embodiments and will not be elaborated here.

[0107] Optionally, the detection device includes a detection electromagnet and a rotational speed sensor.

[0108] Exemplarily, Figure 10 FIG. 14 is a schematic flow chart of another detection method for the overspeed protection device of a wind turbine provided by an embodiment of the present invention. On the basis of the above embodiment, the detection of the overspeed protection device of the wind turbine is further elaborated:

[0109] S410. Obtain the current detected hub rotation speed of the rotational speed sensor, the relationship between the attraction generated by the detection electromagnet when the second end of the overspeed trigger component hits the clutch and its energizing current, and the static attraction; wherein, when the hub is stationary and the second end of the overspeed trigger component hits the clutch, the attraction of the detection electromagnet to the second end of the overspeed trigger component is defined as the static attraction.

[0110] S420. Calculate the current energizing current of the current detection electromagnet according to the hub rotation speed, the relationship between the attraction generated by the detection electromagnet when the second end of the overspeed trigger component hits the clutch and its energizing current, and the static attraction, and record it as the threshold current.

[0111] S430. Provide a current greater than or equal to the threshold current to the detection electromagnet to verify whether the second end of the overspeed trigger component extends to hit the clutch and whether the blades of the wind turbine return to the feathering position within a preset time to determine whether the overspeed protection device of the wind turbine is qualified.

[0112] Optionally, the overspeed trigger component includes at least two first springs and at least two impact blocks corresponding to the first springs one by one; the first end of each first spring serves as the first end of the overspeed trigger component, the second end of the first spring is connected to the corresponding impact block, and the impact block serves as the second end of the overspeed trigger component.

[0113] Exemplarily, Figure 11 FIG. is a schematic flow chart of a method for calculating the energizing current of a current detection electromagnet provided by an embodiment of the present invention. On the basis of the above embodiment, the method for calculating the energizing current of the current detection electromagnet is further described in detail:

[0114] S510. Calculate the centrifugal force received by the impact block according to the hub rotation speed.

[0115] Exemplarily, if the current hub rotation angular velocity is ω; then the centrifugal force F generated by the impact block ω is: F ω = mω 2 r. Where m represents the mass of the impact block, and r represents the distance from the impact block to the rotation center when it just hits the clutch.

[0116] S520. Calculate the attraction force that the current detection electromagnet should generate on the impact block according to the static attraction force and the centrifugal force, and record it as the threshold attraction force.

[0117] Exemplarily, if the static attraction force is F 1 ; the centrifugal force F generated by the impact block ω is: F ω = mω 2 r. Then the threshold attraction force F generated by the detection device is: F = F 1 - F ω .

[0118] S530. Calculate the threshold current according to the relationship between the attraction force generated by the detection electromagnet when the second end of the overspeed trigger component hits the clutch and its energizing current and the threshold attraction force.

[0119] Among them, substituting the threshold attraction force into the relationship between the attraction force generated by the detection electromagnet when the second end of the overspeed trigger component hits the clutch and its energizing current can obtain the minimum current required to energize the detection electromagnet when the impact block hits the clutch, that is, the threshold current.

[0120] It should be noted that: the above calculation process needs to perform a force analysis with the impact block as the force-receiving object.

[0121] Exemplarily, Figure 12 FIG. is a schematic flow chart of another detection method for an overspeed protection device of a wind turbine generator provided by an embodiment of the present invention. On the basis of the above embodiment, the detection of the overspeed protection device of the wind turbine generator is further described in detail:

[0122] S610. Set the mechanical overspeed threshold to be greater than the electrical overspeed threshold.

[0123] Among them, in this solution, an overspeed protection device for a wind turbine is added on the basis of the original electrical overspeed protection of the wind turbine. Therefore, only after the electrical overspeed protection fails, the mechanical overspeed protection device of the wind turbine starts. Therefore, it is necessary to set the mechanical overspeed threshold to be greater than the electrical overspeed threshold.

[0124] It should be noted that: the set mechanical overspeed threshold is not the larger the better. The mechanical overspeed threshold only needs to be slightly greater than the electrical overspeed threshold. Otherwise, the overspeed protection device of the wind turbine cannot play a protective role.

[0125] S620. Obtain the current detected hub rotation speed of the rotational speed sensor, the relationship between the attraction generated by the detection electromagnet when the second end of the overspeed trigger component impacts the clutch and its energizing current, and the static attraction; wherein, when the hub is stationary and the second end of the overspeed trigger component impacts the clutch, the attraction of the detection electromagnet to the impact block is defined as the static attraction.

[0126] S630. Calculate the centrifugal force received by the impact block according to the hub rotation speed.

[0127] S640. Calculate the attraction that the current detection electromagnet should generate for the impact block according to the static attraction and the centrifugal force, denoted as the threshold attraction.

[0128] S650. Calculate the threshold current according to the relationship between the attraction generated by the detection electromagnet when the second end of the overspeed trigger component impacts the clutch and its energizing current and the threshold attraction.

[0129] S660. Disable the electrical overspeed protection.

[0130] S670. Provide a current greater than or equal to the threshold current to the detection electromagnet.

[0131] S680. Verify whether the impact block impacts the clutch to determine whether the overspeed protection device of the wind turbine is qualified.

[0132] S691. If the impact block impacts the clutch and the blades of the wind turbine return to the feathering position within a preset time, the overspeed protection device of the wind turbine is qualified.

[0133] S692. If the impact block does not impact the clutch, or the blades of the wind turbine do not return to the feathering position within a preset time, the overspeed protection device of the wind turbine is unqualified.

[0134] Figure 13 The structural schematic diagram of a wind turbine provided by an embodiment of the present invention is as Figure 13As shown, the wind turbine generator 01 includes the overspeed protection device 02 of the wind turbine generator provided in any embodiment of the present invention, and thus has the beneficial effects of the overspeed protection device 02 of the wind turbine generator provided in the embodiment of the present invention, which will not be elaborated here.

[0135] It should be understood that various forms of processes shown above can be used, steps can be reordered, added or deleted. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and no limitation is made herein.

[0136] The above specific embodiments do not constitute a limitation to the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub - combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A wind turbine overspeed protection device, characterized in that: include: an overspeed trigger assembly and at least two clutches; The clutch is arranged between the pitch motor and the pitch gearbox of the wind turbine generator set, and the clutch is used to transmit or cut off the power input from the pitch motor to the pitch gearbox; The first end of the overspeed trigger assembly is fixed to the rotation center of the wheel hub, and the second end of the overspeed trigger assembly is elastically retractable relative to the first end; when the rotation speed of the wheel hub exceeds the speed limit, the second end of the overspeed trigger assembly extends out to hit the clutch to cut off the power input from the pitch motor to the pitch gearbox; The wind turbine overspeed protection device also includes a pitch changing device; The pitch device comprises a blade bearing and a third spring; One end of the third spring is connected to the outer ring of the blade bearing, and the other end of the third spring is connected to the inner ring of the blade bearing; When the clutch cuts off the power input from the pitch motor to the pitch gearbox, the third spring is used to pull the blade bearing back to the feathering state to decelerate the hub.

2. The overspeed protection device for wind turbine generator set according to claim 1, characterized in that: The overspeed trigger assembly includes at least two first springs and at least two impact blocks corresponding to the first springs one by one; The first end of each of the first springs serves as the first end of the overspeed trigger assembly, and the second end of the first spring is connected to the corresponding impact block, and the impact block serves as the second end of the overspeed trigger assembly; when the wheel hub rotates at an overspeed, the impact block impacts the clutch.

3. The overspeed protection device for wind turbine generator set according to claim 2, characterized in that: The overspeed trigger assembly also includes at least two round tubes; The inner diameter of the circular tube is greater than the diameter of the first spring; each of the first springs is nested in a circular tube, and the circular tube is used to limit the expansion and contraction direction of the first spring.

4. The overspeed protection device for wind turbine generator set according to claim 2, characterized in that: The clutch comprises a clutch body and a clutch handle; The clutch body is connected to the clutch handle, and the impact block impacts the clutch handle to switch the clutch body from an engaged state to a separated state, so as to cut off the power input from the pitch motor to the pitch gearbox.

5. The overspeed protection device for wind turbine generator set according to claim 4, characterized in that: The number of the clutches is equal to the number of the first springs; The clutch handles are connected by a connecting rod mechanism; when the wheel hub rotates at an excessive speed, any one of the impact blocks impacts the clutch handle, driving the clutch bodies connected to the other clutch handles to switch from an engaged state to a disengaged state.

6. The overspeed protection device for wind turbine generator set according to claim 4, characterized in that: The clutch also includes a lock control reset assembly; The lock control reset assembly includes a pin, a second spring and a reset electromagnet; one end of the pin contacts the clutch handle, the other end of the pin is connected to one end of the second spring in a compressed state, and the other end of the second spring is fixed; When the impact block impacts the clutch handle, the pin pops out to separate the clutch handle and the clutch body; When the reset electromagnet is energized, the reset electromagnet generates electromagnetic force to pull back the pin so that the clutch handle and the clutch body are restored to a fitted state, so as to transmit the power input from the pitch motor to the pitch gearbox.

7. The overspeed protection device for wind turbine generator set according to claim 1, characterized in that: Also includes a detection device; The detection device is used to simulate the overspeed state of the wheel hub rotation speed and detect whether the second end of the overspeed trigger assembly extends out and hits the clutch.

8. The overspeed protection device for wind turbine generator set according to claim 7, characterized in that: The detection device includes a detection electromagnet and a rotation speed sensor; The detection electromagnet is used to generate suction force on the second end of the overspeed trigger assembly to simulate the centrifugal force on the second end of the overspeed trigger assembly; the rotation speed sensor is used to detect the rotation speed of the wheel hub.

9. A method for detecting an overspeed protection device of a wind turbine generator set, characterized in that: The wind turbine generator set overspeed protection device comprises: an overspeed trigger component and at least two clutches; The clutch is arranged between the pitch motor and the pitch gearbox of the wind turbine generator set, and is used to transmit or cut off the power input from the pitch motor to the pitch gearbox; the first end of the overspeed trigger assembly is fixed to the rotation center of the hub, and the second end of the overspeed trigger assembly is elastically retractable relative to the first end; The wind turbine generator set overspeed protection device further comprises: a detection device; A detection method for an overspeed protection device of a wind turbine generator set comprises: Obtaining the current rotation speed of the wheel hub, the relationship between the attraction generated by the detection device and the energized current thereof when the second end of the overspeed trigger assembly hits the clutch, and the static attraction; wherein, when the wheel hub is stationary and the second end of the overspeed trigger assembly hits the clutch, the attraction of the detection device to the second end of the overspeed trigger assembly is defined as the static attraction; According to the rotation speed of the wheel hub, the relationship between the attraction force generated by the detection device when the second end of the overspeed trigger assembly hits the clutch and the current flowing through it, and the static attraction force, the current current flowing through the detection device is calculated and recorded as the threshold current; A current greater than or equal to the threshold current is provided to the detection device to verify whether the second end of the overspeed trigger assembly extends and hits the clutch, and whether the blades of the wind turbine generator set return to the feathered position within a preset time, so as to determine whether the overspeed protection device of the wind turbine generator set is qualified.

10. The method for detecting the overspeed protection device of a wind turbine generator set according to claim 9, characterized in that: The detection device includes a detection electromagnet and a rotation speed sensor; A detection method for an overspeed protection device of a wind turbine generator set comprises: Obtaining the wheel hub rotation speed currently detected by the speed sensor, the relationship between the attraction force generated by the detection electromagnet and the energized current thereof when the second end of the overspeed trigger assembly hits the clutch, and the static attraction force; wherein, when the wheel hub is stationary and the second end of the overspeed trigger assembly hits the clutch, the attraction force of the detection electromagnet on the second end of the overspeed trigger assembly is defined as the static attraction force; According to the rotation speed of the wheel hub, the relationship between the attraction force generated by the detection electromagnet and its current when the second end of the overspeed trigger assembly hits the clutch, and the static attraction force, the current current of the detection electromagnet is calculated and recorded as the threshold current; A current greater than or equal to the threshold current is provided to the detection electromagnet to verify whether the second end of the overspeed trigger assembly extends and hits the clutch, and whether the blades of the wind turbine generator set return to the feathered position within a preset time, so as to determine whether the overspeed protection device of the wind turbine generator set is qualified.

11. The detection method of the overspeed protection device of a wind turbine generator set according to claim 10, characterized in that: The overspeed trigger assembly comprises at least two first springs and at least two impact blocks corresponding to the first springs one by one; the first end of each of the first springs serves as the first end of the overspeed trigger assembly, the second end of the first spring is connected to the corresponding impact block, and the impact block serves as the second end of the overspeed trigger assembly; The method for calculating the current of the detection electromagnet comprises: Calculating the centrifugal force exerted on the impact block according to the rotation speed of the wheel hub; According to the static attraction force and the centrifugal force, the current attraction force generated by the detection electromagnet to the impact block is calculated and recorded as the threshold attraction force; The threshold current is calculated according to the relationship between the attraction force generated by the detection electromagnet when the second end of the overspeed trigger assembly hits the clutch and the energized current thereof and the threshold attraction force.

12. The method for detecting an overspeed protection device of a wind turbine generator set according to claim 10, characterized in that: Before obtaining the current rotation speed of the wheel hub, the relationship between the attraction force generated by the detection device and the current supplied thereto, and the static attraction force, the method further includes: Set the mechanical overspeed threshold to be greater than the electrical overspeed threshold; Before providing the detection electromagnet with a current greater than the threshold current, the method further comprises: Shielded electrical overspeed protection.

13. A wind turbine generator set, characterized in that: The invention comprises the overspeed protection device for a wind generator set as claimed in any one of claims 1 to 8.

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