Yaw system, yaw control method and brake control method

Abstract

The invention discloses a yaw system, a yaw control method and a brake control method. The yaw system comprises a main rack, a yaw control device and a brake control device, the yaw gear ring comprises a brake disc located on an inner ring and outer teeth located on an outer ring; the hybrid yaw brake comprises a hydraulic brake module, a mechanical brake module and an inlay for bearing the hydraulic brake module and the mechanical brake module, the hydraulic brake module comprises a hydraulic oil cylinder and a hydraulic brake pad, the mechanical brake module comprises a disc spring and a mechanical brake pad, and a disc spring cylinder body for assembling the disc spring is arranged on the inlay; the yaw driver drives output teeth to be in meshing transmission with outer teeth of the yaw gear ring; wherein the hydraulic brake pad and the mechanical brake pad are located on the lower surface of the brake disc, and an upper pad is arranged on the lower surface of the main rack and located on the upper surface of the brake disc. The yaw braking device has the hydraulic braking function and the mechanical braking function, the inherent defects of a rolling yaw system and a sliding yaw system are overcome, a yaw bearing is omitted, large yaw braking torque can be provided, and the number of yaw drivers is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of wind power generation equipment, and in particular to a yaw system, a yaw control method and a braking control method. Background Art

[0002] During the wind power generation process, the wind rotor of the wind turbine should always be in the windward state to achieve the best wind catching effect. Therefore, the yaw system needs to be equipped with a yaw drive, yaw bearing, and yaw brake to achieve the relative rotation between the nacelle and the tower. In order to avoid the yaw oscillation displacement of the wind turbine during the yaw process, which causes the driving pinion and the large gear ring to collide back and forth, the yaw system must have a suitable damping torque when the unit is yawed. Under the action of the damping torque, the wind rotor of the wind turbine can be accurately positioned in the nacelle and fully utilize wind energy for power generation.

[0003] At present, the yaw damping torque of large wind turbines is generally provided by hydraulic yaw brakes or mechanical brakes. The yaw system must be equipped with several yaw brakes to generate damping torque through the friction between the friction pad of the brake and the yaw brake disc.

[0004] The hydraulic yaw brake needs to build up pressure during braking and release pressure during yaw. The yaw system needs to be equipped with yaw bearings and hydraulic systems. The yaw brake usually uses resin-based friction plates with high friction coefficients, which have a high probability of producing abnormal noise and vibration during operation. The stability of the yaw system operation is greatly affected by the pressure building and pressure release time of the hydraulic system. The stability of the yaw system is relatively low and the failure rate is relatively high. In addition, the yaw system is equipped with yaw bearings, hydraulic systems, and hydraulic brakes, and the overall cost is relatively high.

[0005] The mechanical yaw brake has a relatively simple structure. The yaw brake disc and yaw brake act as yaw bearings, eliminating the hydraulic system and significantly reducing costs. However, the braking force of the yaw system has a bottleneck. The braking torque mostly relies on the yaw drive, which has high requirements on the number and performance of the yaw drive, and is prone to problems such as tooth jamming. In order to achieve sufficient braking torque, more brakes or yaw drives need to be configured.

[0006] Therefore, in view of the above technical problems, how to overcome the shortcomings of the traditional hydraulic yaw brake and the mechanical yaw brake is a technical problem that those skilled in the art need to solve. Summary of the invention

[0007] The purpose of the present application is to provide a yaw system, a yaw control method and a braking control method, wherein the brake has the functions of hydraulic braking and mechanical braking at the same time, thereby solving the inherent shortcomings of rolling yaw and sliding yaw systems, that is, eliminating the yaw bearing, providing a larger yaw braking torque, and reducing the number of yaw drives.

[0008] To achieve the above objectives, the present application provides a yaw system, comprising:

[0009] Main frame;

[0010] A yaw gear ring, rotatably mounted on the main frame, comprising a brake disc on an inner ring and external teeth on an outer ring;

[0011] A hybrid yaw brake, fixedly arranged on the main frame, comprises a hydraulic brake module, a mechanical brake module and an inlay carrying the two, wherein the hydraulic brake module comprises a hydraulic cylinder and a hydraulic brake pad connected to the hydraulic cylinder, and the mechanical brake module comprises a disc spring and a mechanical brake pad connected to the disc spring, and the inlay is provided with a disc spring cylinder body for assembling the disc spring, and the inlay is also provided with a locking bolt for providing a stable pre-tightening force for the disc spring;

[0012] A yaw driver is mounted on the main frame, wherein the driving output teeth of the yaw driver mesh with the external teeth of the yaw gear ring for transmission;

[0013] The hydraulic brake pad and the mechanical brake pad are located on the lower surface of the brake disc, the lower surface of the main frame is provided with upper pads corresponding to the hydraulic brake pad and the mechanical brake pad, and the upper pads are located on the upper surface of the brake disc.

[0014] Preferably, there are multiple hybrid yaw brakes, and the multiple hybrid yaw brakes are evenly distributed along the inner ring of the brake disc.

[0015] Preferably, the inlay includes a lower inlay and an upper inlay, the lower inlay and the upper inlay have a curvature adapted to the brake disc, the upper inlay is located on the upper surface of one side of the inner edge of the lower inlay, the upper inlay is fixedly connected to the main frame, the hydraulic brake pad and the mechanical brake pad are located on the upper surface of one side of the outer edge of the lower inlay, and the upper surface of one side of the outer edge of the lower inlay and the lower surface of the main frame form a space for clamping the brake disc.

[0016] Preferably, any hybrid yaw brake is provided with two hydraulic cylinders and four disc spring cylinder bodies, the number of the hydraulic brake pads and the mechanical brake pads respectively corresponds to the number of the hydraulic cylinders and the disc spring cylinder bodies, the oil circuits of the two hydraulic cylinders are connected in the inlay, and an oil inlet and an oil outlet are provided on the lower inlay.

[0017] Preferably, the oil outlet of the hybrid yaw brake is communicated with the oil inlet of another adjacent hybrid yaw brake to form an oil circuit connecting each hybrid yaw brake in series, wherein there is one oil outlet and one oil inlet for externally connecting hydraulic oil.

[0018] A yaw control method, comprising:

[0019] Determine whether the yaw condition is met. If so, the yaw system executes the yaw command; if not, the yaw brake is maintained;

[0020] When the yaw system executes the yaw command, if the yaw motor driving capacity exceeds the rated torque N times within the preset time T minutes, it enters the yaw waiting stage; otherwise, it performs normal yaw until the yaw requirement is met and stops yaw;

[0021] After entering the yaw waiting stage, when entering the N+1th yaw, the power generation power of the unit is reduced, and after it is reduced to H% of the rated power, the judgment of whether the yaw condition is met is executed.

[0022] A yaw control method, comprising:

[0023] Determine whether the yaw condition is met. If so, the yaw system executes the yaw command; if not, the yaw brake is maintained;

[0024] When the yaw system executes the yaw command, if the yaw system load suddenly increases, causing the yaw system to be unable to meet the yaw condition, the unit triggers the "yaw load is too large" state, at which time the unit stops yaw and enters the yaw waiting stage;

[0025] The "yaw load is too large" state will automatically reset after a preset time, and the unit can enter the yaw waiting state again. If the yaw conditions are met at this time, the unit can yaw again; otherwise, the "yaw load is too large" state will be triggered again.

[0026] Preferably, the yaw system executes the yaw instruction, comprising:

[0027] Hydraulic brake module of hybrid yaw brake releases pressure;

[0028] The electromagnetic brake of the yaw drive is released;

[0029] The yaw motor of the yaw drive is started to perform yaw.

[0030] Preferably, within the detection period of triggering the "yaw load is too large" state, if:

[0031] The number of slow yaw times due to strong wind and large yaw error in the power generation state is greater than the maximum allowed number of slow yaw times due to strong wind and large yaw error in the power generation state;

[0032] Or, the number of slow yaw times in a non-power generation state or a non-strong wind with a large yaw error is greater than the maximum allowed number of slow yaw times in a non-power generation state or a non-strong wind with a large yaw error;

[0033] Or, the sum of the number of slow yaws due to strong wind and large yaw error in the power generation state and the number of slow yaws due to strong yaw error in the non-power generation state / non-strong wind state is greater than the maximum allowable number of slow yaws due to strong wind and large yaw error in the power generation state and the maximum allowable number of slow yaws due to strong wind and large yaw error in the non-power generation state / non-strong wind state;

[0034] The unit triggers a "yaw limited" fault and shuts down for maintenance.

[0035] A braking control method, comprising:

[0036] The proximity switch is used as the identification method for the nacelle position. When the nacelle position is identified to have yaw slipped by 1 pitch, the main control triggers the fault code "yaw slip", but does not alarm or shut down.

[0037] The wind turbine master controller performs power reduction operation, reduces the power to X% of the unit capacity, and detects whether the nacelle position has yawed and slipped by 4 pitches. If so, the master controller immediately issues an alarm to shut down the unit, and the operation can be resumed only after troubleshooting. If not, after T1s of power reduction operation, the wind turbine master controller cancels the power reduction and returns to normal power generation conditions.

[0038] If the fault code "yaw slip" is triggered continuously for more than N1 times within T2 minutes, the main control alarm will shut down the machine for protection, and the operation can be resumed only after the fault is eliminated.

[0039] Compared with the above-mentioned background technology, the yaw system of the present application has the functions of both hydraulic braking and mechanical braking. The braking torque of the mechanical braking is stable and unchanged, while the braking torque of the hydraulic braking changes according to the working state of the yaw system. The coordination of the two braking methods can provide a larger yaw braking torque, reduce the number of yaw drives, and reduce costs; at the same time, it solves the problem that the yaw system is affected by the pressure building, pressure release, and pressure holding time of the hydraulic yaw brake, resulting in stability deviation and high failure rate of the yaw system. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0041] Figure 1 A schematic diagram of the structure of the yaw system provided in an embodiment of the present application;

[0042] Figure 2 A schematic diagram of the coordination structure between the yaw drive and the yaw gear ring provided in an embodiment of the present application;

[0043] Figure 3A front view of a hybrid yaw brake provided in an embodiment of the present application;

[0044] Figure 4 A right side view of the hybrid yaw brake provided in an embodiment of the present application;

[0045] Figure 5 A top view of a hybrid yaw brake provided in an embodiment of the present application;

[0046] Figure 6 A schematic diagram of the installation structure of the hybrid yaw brake provided in an embodiment of the present application;

[0047] Figure 7 A logic diagram for starting the yaw system provided in an embodiment of the present application;

[0048] Figure 8 A yaw system stop logic diagram provided in an embodiment of the present application;

[0049] Fig. 9 A logic diagram of a yaw control method provided in an embodiment of the present application;

[0050] Fig.10 A logic diagram of another yaw control method provided in an embodiment of the present application;

[0051] Fig.11 This is a logic diagram of the braking control method provided in an embodiment of the present application.

[0052] In the figure:

[0053] 1-Main frame; 2-Yaw gear ring; 3-Hybrid yaw brake; 4-Upper pad; 5-Hydraulic oil pipe; 6-Yaw drive;

[0054] 21-external teeth; 22-brake disc;

[0055] 31-lower inlay; 32-upper inlay; 33-oil inlet; 34-oil outlet; 35-locking bolt; 36-side pad; 37-mechanical brake pad; 38-hydraulic brake pad. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0057] It should be noted that in this embodiment, the directions or positional relationships indicated by "upper", "lower", "front", "back", etc. are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present application. In addition, "first", "second", "third", and "fourth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0058] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0059] like Figure 1 and Figure 2 As shown, in this embodiment, a yaw system is provided, which includes a main frame 1, a yaw gear ring 2, a hybrid yaw brake 3 and a driver, wherein the yaw gear ring 2 is rotatably arranged on the main frame 1, and the yaw gear ring 2 includes a brake disc 22 located on the inner ring and an outer tooth 21 located on the outer ring. The hybrid yaw brake 3 can be fixedly arranged on the main frame 1 by high-strength bolts, and includes a hydraulic brake module, a mechanical brake module and an inlay that carries both, wherein the hydraulic brake module includes a hydraulic cylinder and a hydraulic brake pad 38 connected to the hydraulic cylinder, and the mechanical brake module includes a disc spring and a mechanical brake pad 37 connected to the disc spring, and a disc spring cylinder body for assembling the disc spring is provided on the inlay, and a locking bolt 35 for providing a stable pre-tightening force for the disc spring is also provided on the inlay, and the locking bolt 35 can control the compression amount of the disc spring in the disc spring cylinder body by controlling the torque value and the rotation angle of the applied torque, so as to change the braking torque of the mechanical brake module on the yaw system.

[0060] Furthermore, the hydraulic oil cylinder and the hydraulic oil inlet 33 and outlet 34 are connected, and the hydraulic oil builds up pressure and releases pressure to provide braking power. The hydraulic brake pad 38 uses a resin-based polymer friction plate to frictionally brake the brake disc 22 of the yaw gear ring 2; the mechanical brake pad 37 uses a PETP (polyethylene terephthalate plastic, polyester board) high-strength pad to frictionally brake the brake disc 22 of the yaw gear ring 2. 6. It solves the abnormal sound and vibration problems of the traditional rolling yaw system. The high-performance and high-wear-resistant PETP friction material provides a stable braking torque, and completely eliminates industry problems such as howling and abnormal sound under grease lubrication.

[0061] Please refer to Figure 2 The yaw drive 6 is installed on the main frame 1 , and the driving output teeth of the yaw drive 6 are meshed with the outer teeth 21 of the yaw gear ring 2 for transmission.

[0062] Among them, the hydraulic brake pad 38 and the mechanical brake pad 37 are located on the lower surface of the brake disc 22, and the lower surface of the main frame 1 is provided with an upper pad 4 corresponding to the position of the hydraulic brake pad 38 and the mechanical brake pad 37, and the upper pad 4 is located on the upper surface of the brake disc 22, so that the brake disc 22 of the yaw gear ring 2 is clamped between the brake pad (the hydraulic brake pad 38 and the mechanical brake pad 37) and the upper pad 4.

[0063] In summary of the above embodiments, the yaw system of the present application has the functions of hydraulic braking and mechanical braking at the same time. The braking torque of the mechanical braking is stable and unchanged, while the braking torque of the hydraulic braking changes according to the working state of the yaw system. The coordination of the two braking methods can provide a larger yaw braking torque. In the braking state, the hydraulic braking module is in pressurized braking, and in the yaw state, the hydraulic braking module releases pressure and releases the brake. Overall, the number of yaw drives 6 can be reduced, thereby reducing costs. At the same time, the yaw system is affected by the pressure building, pressure relief, and pressure holding time of the hydraulic yaw brake, and the problems of stability deviation and high failure rate of the yaw system are solved.

[0064] Please refer to Figure 6 In some embodiments, there are multiple hybrid yaw brakes 3, and the multiple hybrid yaw brakes 3 are evenly distributed along the inner circle of the brake disc 22, so each hybrid yaw brake 3 can provide a certain braking torque, and the braking power is evenly distributed.

[0065] The inlay includes a lower inlay 31 and an upper inlay 32, please refer to Figure 3 and Figure 4 The lower inlay 31 and the upper inlay 32 have a curvature adapted to the brake disc 22. The upper inlay 32 is located on the upper surface of the inner edge of the lower inlay 31. The upper inlay 32 is fixedly connected to the main frame 1 by high-strength fastening bolts. The hydraulic brake pad 38 and the mechanical brake pad 37 are located on the upper surface of the outer edge of the lower inlay 31. Please refer to Figure 5 At the same time, a side pad 36 is provided on the side of the upper inlay 32 facing the brake disc 22 to prevent the brake disc 22 and the upper inlay 32 from wearing each other. On this basis, the upper surface of the outer edge of the lower inlay 31 can form a space with the lower surface of the main frame 1 to clamp the brake disc 22. In this space, the hydraulic brake pad 38 and the mechanical brake pad 37 are used to achieve friction braking of the brake disc 22. The problem that the braking torque of the mechanical yaw brake is too small and needs to rely on the yaw drive assembly to provide a larger braking torque, and the braking torque cannot be adjusted during braking and yaw is solved.

[0066] In some embodiments, the hybrid yaw brake 3 is provided with two hydraulic cylinders and four disc spring cylinders (not shown in the figure), and the number of hydraulic brake pads 38 and mechanical brake pads 37 corresponds to the number of hydraulic cylinders and disc spring cylinders, respectively, and in order to make the hydraulic brake module and the mechanical brake module provide more balanced braking power, the hydraulic brake pads 38 and the mechanical brake pads 37 can be cross-symmetrically distributed.

[0067] In addition, the oil circuits of the two hydraulic cylinders are connected in the inlay, that is, in a hybrid yaw brake 3, the oil circuit of the first hydraulic cylinder is connected to the oil circuit of the second hydraulic cylinder, and the hydraulic oil can provide braking power by building up pressure and releasing pressure; therefore, each hybrid yaw brake 3 as a whole has only one oil inlet 33 and oil outlet 34, and both are arranged on the lower inlay 31. On this basis, the oil outlet 34 of the hybrid yaw brake 3 is connected to the oil inlet 33 of another adjacent hybrid yaw brake 3 through a hydraulic oil pipe 5 to form an oil circuit of each hydraulic cylinder in series, and there is an oil outlet 34 and an oil inlet 33 for externally connecting hydraulic oil, and a hydraulic system is used to provide hydraulic clamping force for the brake. The problem that a two-circuit hydraulic station must be configured for rolling yaw is solved, and the frequent start and stop of the hydraulic system causes a large number of fault shutdowns and a large number of fault modes.

[0068] Please refer to Figure 7 , Figure 7 is the start-up logic of the yaw system. When the yaw system receives the yaw start command, the hydraulic brake module of the hybrid yaw brake 3 starts to release pressure, switching from full brake pressure to residual pressure. At the same time, the electromagnetic brake of the yaw drive 6 is energized and released. After As, it is completely released. At this time, the yaw motor of the yaw drive 6 is started to start yaw. Since the hydraulic brake module of the hybrid yaw brake 3 releases most of the braking torque at this time, the mechanical brake module provides stable yaw damping.

[0069] Please refer to Figure 8 , Figure 8 This is the stop logic of the yaw system. When the yaw system receives the yaw stop command, the hydraulic brake module of the hybrid yaw brake 3 starts to pressurize. After Es, the yaw motor loses power and stops. After a delay of Fs, the electromagnetic brake of the yaw drive 6 motor loses power and brakes, and the yaw stops. At this time, the hybrid yaw brake 3 provides a large braking torque, which reduces the load on the yaw drive 6.

[0070] Taking into account the harsh operating conditions of wind turbines and the presence of turbulence, typhoons, extreme cold and other environmental conditions, it is difficult for the yaw system to fully cover all extreme conditions when performing yaw actions. However, in order to minimize wind errors, increase the wind turbine rotor wind catching area, and achieve maximum power generation, the yaw strategy of the yaw system is particularly important.

[0071] Therefore, this application proposes a wind turbine yaw strategy, including intermittent yaw and load reduction yaw, which can not only meet the wind turbine functional requirements for wind, but also ensure the stable and reliable operation of the yaw system. Fig. 9 , the control methods of load-reducing yaw include:

[0072] In the case of strong wind conditions (setting wind speed threshold am / s) and large yaw angle (setting wind error bm / s), determine whether the yaw condition is met. If so, the yaw system executes the yaw command; if not, maintain yaw braking;

[0073] When the yaw system executes the yaw command, if the yaw motor driving capacity exceeds the rated torque N times within the preset time T minutes, it enters the yaw waiting stage; otherwise, it performs normal yaw until the yaw requirement is met and stops yaw;

[0074] After entering the yaw waiting stage, when entering the N+1th yaw, the unit's power generation power is reduced, and after it is reduced to H% of the rated power, the above-mentioned step of "determining whether the yaw condition is met" is executed.

[0075] It can be seen that after the unit's power generation is reduced to H% of the rated power, the yaw is performed. At this time, the yaw system load is greatly reduced, the yaw system can stably perform yaw, and the yaw drive components are protected. In addition, the unit completes yaw with power limit, and the power limit is released after the yaw stops. During the power-limited yaw process, if the yaw system fails, the yaw should be stopped immediately and the power limit should be released.

[0076] The advantage of the intermittent yaw control method is that when the wind turbine encounters a sudden change in strong wind (i.e. turbulent wind), the yaw system load suddenly increases, causing the yaw system to be unable to meet the yaw requirements under such environmental conditions. If the unit is to meet the yaw requirements of extreme working conditions, it is necessary to add yaw drive components, resulting in a significant increase in costs.

[0077] If the unit cannot be driven in yaw under extreme working conditions, it can stop yaw and enter waiting mode, and then execute yaw after the severe working conditions are over. This can ensure that the yaw drive capability meets more than 99.9% of environmental working conditions without causing a significant increase in costs, thereby reducing costs and increasing efficiency.

[0078] For details, please refer to Fig.10 , the control methods of intermittent yaw include:

[0079] Determine whether the yaw condition is met. If so, the yaw system executes the yaw command; if not, the yaw brake is maintained;

[0080] When the yaw system executes the yaw command, if the yaw system load suddenly increases, causing the yaw system to be unable to meet the yaw condition, the unit triggers the "yaw load is too large" state, at which time the unit stops yaw and enters the yaw waiting stage;

[0081] The "yaw load is too large" state will automatically reset after a preset time (30s). When the "yaw load is too large" state is eliminated, the unit can enter the yaw waiting state again. If the wind requirements are still met at this time, the unit can yaw against the wind again, thereby achieving intermittent yaw, which can not only filter out extreme turbulent wind conditions, but also give the yaw motor and thermal protection electrical components a certain cooling time to dissipate the heat accumulation caused by overload and protect the motor and electrical components.

[0082] In addition, when performing intermittent yaw, if any of the following conditions are met, the unit will trigger the "yaw limited" fault and immediately shut down for protection. It can only be reset after the fault is corrected to ensure the overall safety of the wind turbine generator set;

[0083] Condition 1: The number of slow yaw times due to strong wind and large yaw error in the power generation state is greater than the maximum allowable number of slow yaw times due to strong wind and large yaw error in the power generation state;

[0084] Condition 2: The number of slow yaw times in the non-power generation state or in the non-strong wind with large yaw error is greater than the maximum allowed number of slow yaw times in the non-power generation state or in the non-strong wind with large yaw error;

[0085] Condition three: The sum of the number of slow yaw times due to strong wind and large yaw error in the power generation state and the number of slow yaw times due to large yaw error in the non-generator state / non-strong wind is greater than the maximum value of the maximum allowable number of slow yaw times due to strong wind and large yaw error in the power generation state and the maximum allowable number of slow yaw times due to large yaw error in the non-power generation state / non-strong wind.

[0086] For intermittent yaw and load-reducing yaw, the steps of the yaw system executing the yaw command include:

[0087] The hydraulic brake module of the hybrid yaw brake 3 releases the pressure and releases the brake;

[0088] The electromagnetic brake of the yaw drive 6 is released;

[0089] The yaw motor of the yaw drive 6 is started to perform yaw.

[0090] It should be pointed out that when the braking capacity of the yaw system of the present application is still insufficient under extreme wind conditions, the braking control method provided by the present application can be used to cope with it, thereby avoiding the cost increase caused by adding yaw motors and yaw brakes.

[0091] For details, please refer to Fig.11 , the braking control method includes:

[0092] The proximity switch is used as the identification method for the nacelle position. When the nacelle position is identified to have yaw slipped by 1 pitch, the main control triggers the fault code "yaw slip", but does not alarm or shut down.

[0093] The wind turbine master controller performs power reduction operation, reduces the power to X% of the unit capacity, and detects whether the nacelle position has yawed and slipped by 4 pitches. If so, the master controller immediately issues an alarm to shut down the unit, and the operation can be resumed only after troubleshooting. If not, after T1s of power reduction operation, the wind turbine master controller cancels the power reduction and returns to normal power generation conditions.

[0094] If the fault code "yaw slip" is triggered continuously for more than N1 times within T2 minutes, the main control alarm will shut down the machine for protection, and the operation can be resumed only after the fault is eliminated.

[0095] It should be pointed out that the above-mentioned parameters, such as T, N, H, X, etc., are all preset values ​​and can be set according to actual conditions, and will not be described in detail here.

[0096] The yaw control method and the braking control method mentioned above can both be implemented based on the yaw system, that is, both the yaw control method and the braking control method can be applied to the yaw system described above.

[0097] From the above, it can be seen that the present application can solve the problem of heavy load and large impact on the yaw drive 6 under turbulent wind conditions, and can reduce the problem of tooth snapping of the yaw drive 6 caused by cabin slippage; through the above control method, the problem of insufficient yaw capacity under extreme working conditions is solved, and the failure caused by overload of the yaw drive component is reduced; the problem of insufficient braking capacity under extreme working conditions is solved, and the yaw system can better cope with extreme working conditions and reduce the mass loss caused by yaw slippage.

[0098] It should be noted that, in this specification, relational terms such as first and second are merely used to distinguish one entity from other entities, but do not necessarily require or imply any actual relationship or order between these entities.

[0099] Specific examples are used herein to illustrate the principles and implementation methods of the present application, and the description of the above embodiments is only used to help understand the method and core ideas of the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A yaw system, characterized in that: include: Main frame (1); A yaw gear ring (2) rotatably mounted on the main frame (1), comprising a brake disc (22) located on an inner ring and external teeth (21) located on an outer ring; A hybrid yaw brake (3) is fixedly mounted on the main frame (1), comprising a hydraulic brake module, a mechanical brake module and an inlay supporting the hydraulic brake module and the mechanical brake module, wherein the hydraulic brake module comprises a hydraulic cylinder and a hydraulic brake pad (38) connected to the hydraulic cylinder, and the mechanical brake module comprises a disc spring and a mechanical brake pad (37) connected to the disc spring, wherein the inlay is provided with a disc spring cylinder for assembling the disc spring, and the inlay is also provided with a locking bolt (35) for providing a stable pre-tightening force for the disc spring; A yaw drive (6) is mounted on the main frame (1), wherein a drive output tooth of the yaw drive (6) meshes with the outer tooth (21) of the yaw gear ring (2) for transmission; The hydraulic brake pad (38) and the mechanical brake pad (37) are located on the lower surface of the brake disc (22); an upper pad (4) corresponding to the hydraulic brake pad (38) and the mechanical brake pad (37) is provided on the lower surface of the main frame (1); and the upper pad (4) is located on the upper surface of the brake disc (22).

2. The yaw system according to claim 1, characterized in that: The number of the hybrid yaw brakes (3) is multiple, and the multiple hybrid yaw brakes (3) are evenly distributed along the inner ring of the brake disc (22).

3. The yaw system according to claim 2, characterized in that: The inlay comprises a lower inlay (31) and an upper inlay (32), the lower inlay (31) and the upper inlay (32) having a curvature adapted to the brake disc (22), the upper inlay (32) being located on an upper surface on one side of an inner edge of the lower inlay (31), the upper inlay (32) being fixedly connected to the main frame (1), the hydraulic brake pad (38) and the mechanical brake pad (37) being located on an upper surface on one side of an outer edge of the lower inlay (31), and the upper surface on one side of the outer edge of the lower inlay (31) and the lower surface of the main frame (1) forming a space for clamping the brake disc (22).

4. The yaw system according to claim 3, characterized in that: Any of the hybrid yaw brakes (3) is provided with two hydraulic cylinders and four disc spring cylinder bodies, the number of the hydraulic brake pads (38) and the mechanical brake pads (37) respectively corresponds to the number of the hydraulic cylinders and the disc spring cylinder bodies, the oil circuits of the two hydraulic cylinders are connected in the inlay, and an oil inlet (33) and an oil outlet (34) are provided on the lower inlay (31).

5. The yaw system according to claim 4, characterized in that: The oil outlet (34) of the hybrid yaw brake (3) is in communication with the oil inlet (33) of another adjacent hybrid yaw brake (3) to form an oil circuit that connects each hydraulic cylinder in series, wherein one of the oil outlets (34) and one of the oil inlets (33) are connected to external hydraulic oil.

6. A yaw control method, characterized in that: include: Determine whether the yaw condition is met, if so, the yaw system executes the yaw command; If not, maintain yaw braking; When the yaw system executes the yaw command, if the yaw motor driving capacity exceeds the rated torque N times within the preset time T minutes, it enters the yaw waiting stage; otherwise, it performs normal yaw until the yaw requirement is met and stops yaw; After entering the yaw waiting stage, when entering the N+1th yaw, the power generation power of the unit is reduced, and after it is reduced to H% of the rated power, the judgment of whether the yaw condition is met is executed.

7. A yaw control method, characterized in that: include: Determine whether the yaw condition is met. If so, the yaw system executes the yaw command; if not, the yaw brake is maintained; When the yaw system executes the yaw command, if the yaw system load suddenly increases, causing the yaw system to be unable to meet the yaw condition, the unit triggers the "yaw load is too large" state, at which time the unit stops yaw and enters the yaw waiting stage; The "yaw load is too large" state will automatically reset after a preset time, and the unit can enter the yaw waiting state again. If the yaw conditions are met at this time, the unit can yaw again; otherwise, the "yaw load is too large" state will be triggered again.

8. The yaw control method according to claim 6 or 7, characterized in that: The yaw system executes the yaw instruction, including: The hydraulic brake module of the hybrid yaw brake (3) releases the pressure and releases the brake; The electromagnetic brake of the yaw drive (6) is released; The yaw motor of the yaw drive (6) is started to perform yaw.

9. The yaw control method according to claim 7, characterized in that: During the detection cycle that triggers the "yaw load is too large" state, if: The number of slow yaw times due to strong wind and large yaw error in the power generation state is greater than the maximum allowed number of slow yaw times due to strong wind and large yaw error in the power generation state; Or, the number of slow yaw times in a non-power generation state or a non-strong wind with a large yaw error is greater than the maximum allowed number of slow yaw times in a non-power generation state or a non-strong wind with a large yaw error; Or, the sum of the number of slow yaws due to strong wind and large yaw error in the power generation state and the number of slow yaws due to strong yaw error in the non-power generation state / non-strong wind state is greater than the maximum allowable number of slow yaws due to strong wind and large yaw error in the power generation state and the maximum allowable number of slow yaws due to strong wind and large yaw error in the non-power generation state / non-strong wind state; The unit triggers a "yaw limited" fault and shuts down for maintenance.

10. A braking control method, characterized in that: include: A proximity switch is used as the method for identifying the position of the nacelle. When the nacelle position is identified to have yawed by 1 pitch, the main control triggers the fault code "yaw slip", but does not give an alarm or shut down the machine. The wind turbine master controller performs power reduction operation, reduces the power to X% of the unit capacity, and detects whether the nacelle position has yawed and slipped by 4 pitches. If so, the master controller immediately issues an alarm to shut down the unit, and the operation can be resumed only after troubleshooting. If not, after T1s of power reduction operation, the wind turbine master controller cancels the power reduction and returns to normal power generation conditions. If the fault code "yaw slip" is triggered continuously for more than N1 times within T2 minutes, the main control alarm will shut down the machine for protection, and the operation can be resumed only after the fault is eliminated.

Images