Yaw control method for wind turbine generator system, system thereof and wind turbine generator system

Abstract

The application provides a yaw control method and system of a wind turbine generator and the wind turbine generator. The wind turbine generator comprises a wind wheel and a generator, and the direction of the torque generated by the generator is consistent with the yaw direction of the wind turbine generator. The yaw control method of the wind turbine generator comprises the following steps: obtaining the current nacelle angle of the wind turbine generator and the current wind direction angle of the incoming flow; determining that the wind turbine generator needs to yaw when the nacelle angle exceeds the wind direction angle by a predetermined threshold; determining the required yaw angle of the wind turbine generator; controlling the imbalance between the wind wheel torque generated by the wind wheel and the generator torque generated by the generator based on the required yaw angle; and controlling the unlocking of the yaw mechanical brake in the wind turbine generator to execute the yaw of the wind turbine generator through the imbalance between the wind wheel torque and the generator torque. Thus, the yaw driving motor can be omitted, and the cost is greatly reduced.

Description

Technical Field

[0001] This application relates to the field of wind power generation technology, and in particular to a yaw control method and system for a wind turbine generator set and a wind turbine generator set. Background Technology

[0002] With the gradual depletion of energy sources such as coal and oil, humanity is increasingly emphasizing the utilization of renewable energy. Wind energy, as a clean and renewable energy source, is receiving growing attention worldwide. Along with the continuous development of wind power technology, the application of wind turbine generators in power systems is increasing. Wind turbine generators are large-scale devices that convert wind energy into electrical energy, typically installed in areas rich in wind resources.

[0003] Wind turbine generators include a yaw system. The yaw system, also known as a wind-aligning device, is installed on the upper part of the nacelle of the wind turbine generator. Its function is to quickly and smoothly align with the wind direction when the wind speed changes, so that the wind turbine can obtain maximum wind energy. After aligning, it provides the necessary locking torque to ensure the safe and stable operation of the wind turbine generator after the aligning operation. Existing yaw systems basically use a yaw drive motor to drive the nacelle to yaw. However, yaw drive motors are relatively expensive. Summary of the Invention

[0004] The purpose of this application is to provide a yaw control method and system for wind turbine generator sets, as well as a wind turbine generator set, which can achieve yaw control of wind turbine generator sets without the need for a separate yaw drive motor.

[0005] One aspect of this application provides a yaw control method for a wind turbine generator set, wherein the wind turbine generator set includes a wind turbine and a generator, and the direction of the torque generated by the generator is consistent with the yaw direction of the wind turbine generator set. The yaw control method includes: acquiring the current nacelle angle of the wind turbine generator set and the current wind direction angle of the incoming wind; determining that the wind turbine generator set needs to yaw when the nacelle angle exceeds a predetermined threshold of the wind direction angle; determining the required yaw angle of the wind turbine generator set; controlling an imbalance between the wind turbine torque generated by the wind turbine and the generator torque generated by the generator based on the required yaw angle; and controlling the unlocking of the wind turbine generator set...

[0006] The yaw mechanical brake is used to perform yaw of the wind turbine generator set by means of the imbalance between the rotor torque and the generator torque.

[0007] Another aspect of this application provides a yaw control system for a wind turbine generator set, which includes one or more processors for implementing the yaw control method for the wind turbine generator set as described above.

[0008] Another aspect of this application provides a wind turbine generator set. The wind turbine generator set includes a yaw control system as described above.

[0009] The yaw control method and system of wind turbine generator set according to one or more embodiments of this application, and the wind turbine generator set, by setting the torque generated by the generator to be consistent with the yaw direction of the wind turbine generator set, can use the imbalance between the torque generated by the wind turbine and the torque generated by the generator to drive the nacelle of the wind turbine generator set to yaw, thereby realizing the yaw of the wind turbine generator set. Therefore, the yaw drive motor can be eliminated, which can greatly reduce the cost. 5. Attached Figure Descriptions

[0010] Figure 1 This is a perspective view of a wind turbine generator set according to an embodiment of this application.

[0011] Figure 2 This is a cross-sectional schematic diagram of a wind turbine generator set according to an embodiment of this application.

[0012] Figure 3 for Figure 2 The image shows a top view of a wind turbine generator set.

[0013] Figure 4 This is a flowchart of a yaw control method for a wind turbine generator set according to an embodiment of this application.

[0014] 0 Figure 5 This application describes the specific steps for controlling and adjusting the generator torque and / or wind turbine torque based on the unbalanced torque difference to generate the yaw torque of a wind turbine generator set, according to one embodiment of the present application.

[0015] Figure 6 Another embodiment of this application uses unbalanced torque difference to control and adjust generator torque and / or...

[0016] The specific steps for generating yaw torque in a wind turbine generator, or the rotor torque.

[0017] Figure 7 This is a schematic block diagram of a yaw control system for a wind turbine generator set according to an embodiment of this application. Detailed Implementation

[0018] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses consistent with some aspects of this application as detailed in the appended claims.

[0019] The terminology used in the embodiments of this application is for the purpose of describing specific embodiments only and is not intended to limit the application. Unless otherwise defined, the technical or scientific terms used in the embodiments of this application should be understood in their ordinary sense by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are only used to distinguish different components. Similarly, the terms "a" or "one" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. "A plurality" or "several" indicates two or more. Unless otherwise indicated, the terms "front," "rear," "lower," and / or "upper" and similar terms are for ease of description only and are not limited to a location or spatial orientation. The terms "comprising" or "including" and similar terms mean that the elements or objects preceding "comprising" or "including" cover the elements or objects listed after "comprising" or "including" and their equivalents, and do not exclude other elements or objects. The terms "connected" or "linked" and similar terms are not limited to physical or mechanical connections and can include electrical connections, whether direct or indirect. The singular forms “a,” “the,” and “the” used in this application specification and appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0020] This application provides a wind turbine generator set 100. Figure 1 A perspective view of a wind turbine generator set 100 according to one embodiment of this application is shown. Figure 1 As shown, the wind turbine generator set 100 includes a rotor 110, a nacelle 120, and a tower 130. The rotor 110 has multiple blades, typically three blades. The nacelle 120 is mounted at the top of the tower 130, and the rotor 110 is mounted at one end of the nacelle 120.

[0021] Figure 2 A cross-sectional schematic diagram of a wind turbine generator set 100 according to one embodiment of this application is shown. Figure 2As shown, the wind turbine generator set 100 of this embodiment further includes a generator 140 and a drive chain 150. The generator 140 includes a rotor 141 and a stator, wherein the stator is formed by a portion of a tower 130. In some embodiments, the upper end of the tower 130 forms the stator, and the rotor 141 is rotatably mounted on the upper end of the tower 130. The rotation axis of the generator 140 coincides with the central axis of the tower 130. The wind turbine 110 can be driven to the rotor 141 of the generator 140 via the drive chain 150. The drive chain 150 includes a main shaft 151 and a steering transmission mechanism. The wind turbine 110 is mounted at one end of the main shaft 151, and the rotation axis of the wind turbine 110 forms an angle with the central axis of the tower 130. The steering transmission mechanism can be used to change the rotation direction of the main shaft 151 to the rotation direction of the rotor 141 of the generator 140.

[0022] In some embodiments, the steering transmission mechanism of the wind turbine generator set 100 of this application may include a pair of meshing bevel gears 152, wherein the direction of the wind turbine torque M2 generated by the wind turbine 110 can be changed to be consistent with the direction of the generator torque M1 generated by the generator 140 through the bevel gear pair 152. The bevel gears may be, for example, spiral bevel gears. This application can use the bevel gear pair 152 to change the torque direction. Bevel gears are typically used for transmission between two shafts with an angle of approximately 90 degrees. In the embodiments of this application, by using the bevel gear pair 152 in the wind turbine generator set 100, the direction of the wind turbine torque M2 generated by the wind turbine 110 can be changed to be consistent with the direction of the generator torque M1 generated by the generator 140. Moreover, bevel gears (especially spiral bevel gears) can efficiently transmit torque and can adapt to deformation of the drive chain 150.

[0023] In some embodiments, a bevel gear pair 152 is disposed between the main shaft 151 and the rotor 141 of the generator 140. The bevel gear pair 152 can provide a certain gear ratio so that the rotational speed of the wind turbine 110 matches the rotational speed of the rotor 141 of the generator 140. One of the bevel gears 152 engages with the main shaft 151; for example, one of the bevel gears 152 can be mounted at the other end of the main shaft 151, and the other of the bevel gears 152 engages with the shaft of the rotor 141. Thus, the rotational direction of the main shaft 151 can be adjusted to match the rotational direction of the rotor 141 through the bevel gear pair 152.

[0024] When the wind turbine 110 rotates, the rotation of the wind turbine 110 can drive the main shaft 151 to rotate, and the rotation of the main shaft 151 in turn drives the bevel gear pair 152 to rotate, which in turn drives the rotor 141 of the generator 140 to rotate.

[0025] In other embodiments, when the bevel gear pair 152 cannot provide a high enough gear ratio to match the rotational speed of the wind turbine 110 with the rotational speed of the rotor 141 of the generator 140, the drive chain 150 of the wind turbine generator set 100 of this application may further include a gearbox (not shown), which is disposed between the main shaft 151 and the steering transmission mechanism. For example, the gearbox is disposed between the main shaft 151 and the bevel gear pair 152. The gearbox is disposed at the other end of the main shaft 151. One of the bevel gears 152 meshes with the output shaft of the gearbox, and the other of the bevel gear pair 152 meshes with the shaft of the rotor 141. In one embodiment, the gearbox is a speed-increasing gearbox to achieve the purpose of speed increase.

[0026] When the wind turbine 110 rotates, the rotation of the wind turbine 110 can drive the main shaft 151 to rotate, the rotation of the main shaft 151 in turn drives the gearbox to rotate, and then drives the output shaft to rotate. The rotation of the output shaft of the gearbox further drives the bevel gear pair 152 to rotate, thereby driving the rotor 141 of the generator 140 to rotate.

[0027] Continue to refer to Figure 2 As shown, the drive chain 150 includes a drive chain bracket 154, which is rotatably mounted on the top of the tower 130 via a yaw bearing 160. The drive chain 150 also includes a bearing housing 155 disposed on the drive chain bracket 154, and a main bearing (not labeled) is provided in the bearing housing 155. The main shaft 151 can be rotatably mounted in the bearing housing 155 via the main bearing.

[0028] The wind turbine generator set 100 of this application embodiment also includes a yaw mechanical brake. The yaw mechanical brake is disposed between the drive chain support 154 and the top of the tower 130. The yaw mechanical brake may include, for example, a brake plate 171 disposed on one of the drive chain support 154 and the tower 130, and a yaw brake caliper 172 disposed on the other of the drive chain support 154 and the tower 130. By cooperating with the brake plate 171, the yaw brake of the nacelle 120 of the wind turbine generator set 100 can be locked or unlocked, realizing the yaw mechanical brake locking or unlocking function of the wind turbine generator set 100.

[0029] The wind turbine generator set 100 of this application embodiment also includes a pitch system (not shown) and a converter (not shown). The pitch system can be used to drive the pitch angle of the blades. The converter can be used to control the generator 140.

[0030] In the wind turbine generator set 100 of this application embodiment, since the torque M1 generated by the generator 140 is consistent with the yaw direction of the wind turbine generator set 100, this characteristic can be applied to the yaw control of the wind turbine generator set 100. The following will combine... Figure 3This section details how this feature is applied to the yaw control process of the wind turbine generator set 100.

[0031] Figure 3 Revealed Figure 2 The image shows a top view of the wind turbine generator set 100. Figure 3 As shown, let's first take the case of no wind as an example, assuming the incoming wind direction is from... Figure 3 When the solid arrow in the diagram changes to a dashed arrow, clockwise yaw is required. If the generator 140 provides additional torque, and if the yaw brake caliper 172 and brake plate 171 are still locked together, this additional torque will cause the rotor 110 to rotate. However, if the mechanical brake between the yaw brake caliper 172 and brake plate 171 is released, and the pneumatic brake is activated by adjusting the blade pitch angle through the pitch system (i.e., adjusting the blade attitude), preventing the rotor 110 from rotating, the additional torque provided by the generator 140 has nowhere to be released and can only drive yaw rotation, causing the entire nacelle 120 to rotate.

[0032] Therefore, having understood the process under the above windless conditions, let's consider adding wind. Continue referring to... Figure 3 As shown, similarly, assuming the incoming airflow direction is from... Figure 3 When the solid arrow in the diagram changes to a dashed arrow, clockwise yaw is required. Initially, the wind turbine torque M2 generated by the wind turbine 110 and the generator torque M1 generated by the generator 140 are balanced, i.e., M1 = M2. If the generator 140 provides an additional torque, for example, by increasing the generator torque, the generator torque will increase from M1 to M1_1. If the yaw brake caliper 172 is still locked to the brake plate 171, the increased torque provided by the generator 140 will cause the wind turbine 110 to rotate faster. Of course, many situations can arise, and whether the wind turbine 110 rotates faster or slower depends on whether the torque change and the direction of rotation of the wind turbine 110 are consistent. This is just an example to illustrate the point. However, if the mechanical brake between the yaw brake caliper 172 and the brake plate 171 is released at this time, and the pneumatic brake is activated by adjusting the pitch angle of the blades through the pitch system, that is, adjusting the attitude of the blades so that the speed of the wind turbine 110 is constant, then the extra torque provided by the generator 140 has nowhere to be released, and can only drive the yaw rotation, so that the entire nacelle 120 rotates.

[0033] Therefore, after understanding the yaw principle above, the following will combine... Figure 4 This application will describe in detail the yaw control method provided for the wind turbine generator set 100 described above. Figure 4A flowchart illustrating a yaw control method for a wind turbine generator according to an embodiment of this application is provided. Figure 4 As shown, a yaw control method for a wind turbine generator set according to an embodiment of this application may include steps S11 to S16.

[0034] In step S11, the current nacelle angle of the wind turbine generator set 100 and the current wind direction angle of the incoming wind are obtained.

[0035] In step S12, it is determined whether the cabin angle exceeds a predetermined threshold for wind direction angle. If the determination is yes, the process proceeds to step S13. Otherwise, the process returns to step S11.

[0036] In step S13, when the nacelle angle exceeds the predetermined threshold of the wind direction angle, it is determined that the wind turbine generator set 100 needs to yaw.

[0037] In step S14, when it is determined that the wind turbine generator set 100 needs to yaw, the required yaw angle of the wind turbine generator set 100 is determined. The required yaw angle of the wind turbine generator set 100 is equal to the difference between the nacelle angle and the wind direction angle.

[0038] In step S15, an imbalance is created between the wind turbine torque M2 generated by the wind turbine 110 and the generator torque M1 generated by the generator 140, based on the required yaw angle determined in step S14.

[0039] The required unbalanced torque difference between the rotor torque M2 and the generator torque M1 can be determined based on the desired yaw angle. Then, the generator torque M1 and / or rotor torque M2 can be controlled and adjusted based on the unbalanced torque difference to generate the yaw torque of the wind turbine generator set 100.

[0040] In the embodiment where the wind turbine generator set 100 is a direct-drive unit and the wind rotor 110 and the generator 140 are directly connected by transmission, the unbalanced torque difference is equal to the torque difference between the wind rotor torque M2 and the generator torque M1.

[0041] In the embodiment where the wind turbine generator set 100 is a non-direct drive unit and the wind rotor 110 and the generator 140 are connected by a gearbox transmission, the unbalanced torque difference is equal to the torque difference between the wind rotor torque M2 divided by the gearbox speed ratio and the generator torque M1.

[0042] In step S16, the yaw mechanical brake in the wind turbine generator set 100 is unlocked, that is, the yaw brake caliper 172 and brake plate 171 between the drive chain bracket 154 and the tower 130 are released, so that the nacelle 120 of the wind turbine generator set 100 can be driven to yaw by the imbalance between the rotor torque M2 and the generator torque M1, thus performing the yaw of the wind turbine generator set 100.

[0043] Figure 5 This application discloses specific steps in one embodiment of the method for controlling and adjusting the generator torque M1 and / or the wind turbine torque M2 based on the unbalanced torque difference to generate the yaw torque of the wind turbine generator set 100. For example... Figure 5 As shown, controlling and adjusting the generator torque M1 and / or the wind turbine torque M2 based on the unbalanced torque difference to generate the yaw torque of the wind turbine generator set 100 may include steps S21 and S22.

[0044] In step S21, the current wind turbine torque M2 can be controlled to remain within a predetermined threshold range.

[0045] Considering that in actual control, due to various factors, it is difficult to maintain the wind turbine torque at a completely constant value, the current wind turbine torque M2 can be controlled and maintained within a predetermined threshold range. For example, the wind turbine torque can be controlled within the range of the current wind turbine torque value plus or minus a predetermined threshold.

[0046] In some embodiments, controlling the current wind turbine torque M2 to remain within a predetermined threshold range may include: controlling the wind turbine generator set 100 to maintain the current pitch angle to activate the pneumatic brake of the wind turbine 110 so that the rotational speed of the wind turbine 110 is substantially constant.

[0047] In step S22, the generator torque M1 is adjusted based on the unbalanced torque difference to generate yaw torque.

[0048] In some embodiments, step S22, which controls and adjusts the generator torque M1 based on the unbalanced torque difference to generate yaw torque, may further include steps S221 to S224.

[0049] In step S221, the current generator torque M1 is obtained.

[0050] In step S222, the generator torque M1 to be adjusted for generator 140 is determined based on the unbalanced torque difference and the current generator torque M1 obtained in step S221.

[0051] In step S223, the control parameters of the converter are controlled based on the generator torque M1 to be adjusted determined in step 222.

[0052] In step S224, the generator torque M1 is adjusted by adjusting the control parameters of the converter to generate yaw torque.

[0053] Therefore, the yaw of the wind turbine generator 100 can be controlled using the generator torque M1 without the need for a yaw drive motor, making the control method simple and easy to implement. Moreover, since the yaw drive motor can be eliminated, the cost can be greatly reduced.

[0054] Figure 6 This application discloses specific steps for controlling and adjusting the generator torque M1 and / or wind turbine torque M2 based on the unbalanced torque difference to generate the yaw torque of the wind turbine generator set 100, according to another embodiment of this application. Figure 6 As shown, controlling and adjusting the generator torque M1 and / or the wind turbine torque M2 based on the unbalanced torque difference to generate the yaw torque of the wind turbine generator set 100 may include steps S31 and S32.

[0055] In step S31, the current generator torque M1 can be controlled to remain within a predetermined threshold range.

[0056] Considering that in actual control, due to various factors, it is difficult to maintain the generator torque at a completely constant value, the current generator torque M1 can be controlled and maintained within a predetermined threshold range. For example, the generator torque can be controlled within the range of the current generator torque value plus or minus a predetermined threshold.

[0057] In some embodiments, controlling the current generator torque M1 to remain within a predetermined threshold range may include controlling the control parameters of the holding converter to maintain the current generator torque M1.

[0058] In step S32, the wind turbine torque M2 is controlled and adjusted based on the unbalanced torque difference to generate yaw torque.

[0059] In some embodiments, the step S32, which controls and adjusts the wind turbine torque M2 based on the unbalanced torque difference to generate yaw torque, may further include steps S321 to S324.

[0060] In step S321, the current pitch angle of the blades of the wind turbine 110 is obtained.

[0061] In step S322, the adjusted pitch angle of the blade is determined based on the unbalanced torque difference and the current pitch angle obtained in step S321.

[0062] In step S323, the blades are pitched based on the pitch angle to be adjusted determined in step 322.

[0063] In step S324, the rotor torque M2 is adjusted by adjusting the blade pitch to generate yaw torque.

[0064] Therefore, yaw torque can be generated through pitch adjustment, enabling more effortless yaw control of the wind turbine generator 100 without the need for a yaw drive motor, making the control method simple and easy to implement. Moreover, since the yaw drive motor can be eliminated, costs can be significantly reduced.

[0065] Return to continue referencing Figure 4 In some embodiments, the yaw control method for wind turbine generator sets of this application may further include steps S17 and S18.

[0066] In step S17, it is determined whether the wind turbine generator 100 has yawed to the correct position. If the result is yes, the process continues to step S18. Otherwise, it returns to continue the determination.

[0067] In step S18, after the wind turbine generator set 100 yaws to the desired position, the yaw mechanical brake in the wind turbine generator set 100 is locked, that is, the yaw brake caliper 172 is locked together with the brake plate 171, thereby completing the entire yaw action of the wind turbine generator set.

[0068] The yaw control method of the wind turbine generator set in this application sets the torque generated by the generator 140 to be consistent with the yaw direction of the wind turbine generator set 100. In this way, the imbalance between the wind turbine torque M2 generated by the wind turbine 110 and the generator torque M1 generated by the generator 140 can be used to drive the nacelle 120 of the wind turbine generator set 100 to yaw, thereby realizing the yaw of the wind turbine generator set 100. Therefore, the yaw drive motor can be eliminated, which can greatly reduce the cost.

[0069] Moreover, the yaw control method of the wind turbine generator set in this application is simple and easy to implement.

[0070] This application also provides a yaw control system 200 for a wind turbine generator set. Figure 7 A schematic block diagram of a yaw control system 200 for a wind turbine generator set according to one embodiment of this application is shown. Figure 7 As shown, the yaw control system 200 of a wind turbine generator set according to one embodiment of this application may include one or more processors 201 for implementing the yaw control method of the wind turbine generator set as described in the above embodiments.

[0071] The yaw control system 200 of the wind turbine generator set in this application embodiment has beneficial technical effects that are generally similar to the yaw control method of the wind turbine generator set described above, so it will not be described again here.

[0072] The foregoing has provided a detailed description of the yaw control method and system for wind turbine generators, as well as the wind turbine generator itself, provided in the embodiments of this application. Specific examples have been used to illustrate the yaw control method and system for wind turbine generators, as well as the wind turbine generator itself, in the embodiments of this application. The descriptions of the embodiments above are merely for the purpose of helping to understand the core ideas of this application and are not intended to limit this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from the spirit and principles of this application, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A yaw control method for a wind turbine generator set, the wind turbine generator set comprising a wind rotor and a generator, characterized in that: The direction of the torque generated by the generator is consistent with the yaw direction of the wind turbine generator set, and the yaw control method includes: Obtain the current nacelle angle and the current wind direction angle of the incoming wind from the wind turbine generator set; When the nacelle angle exceeds the predetermined threshold of the wind direction angle, it is determined that the wind turbine needs to yaw. Determine the required yaw angle for the wind turbine generator set; Controlling the imbalance between the wind turbine torque and the generator torque based on the required yaw angle includes: determining the required imbalance torque difference between the wind turbine torque and the generator torque based on the required yaw angle; and controlling and adjusting the generator torque and / or the wind turbine torque based on the imbalance torque difference to generate the yaw torque of the wind turbine generator set; and Control the unlocking of the yaw mechanical brake in the wind turbine generator set to perform yaw of the wind turbine generator set by the imbalance between the rotor torque and the generator torque.

2. The yaw control method as described in claim 1, characterized in that: The method of controlling and adjusting the generator torque and / or the wind turbine torque based on the unbalanced torque difference to generate the yaw torque of the wind turbine generator set includes: Control the current wind turbine torque to remain within a predetermined threshold range; and The generator torque is controlled and adjusted based on the unbalanced torque difference to generate the yaw torque.

3. The yaw control method as described in claim 2, characterized in that: The control of the current wind turbine torque to remain within a predetermined threshold range includes: The pneumatic brakes of the wind turbine are activated by maintaining the current pitch angle of the wind turbine generator set to keep the rotational speed of the wind turbine essentially constant.

4. The yaw control method as described in claim 2, characterized in that: The wind turbine generator set also includes a converter for controlling the generator, wherein controlling and adjusting the generator torque based on the unbalanced torque difference to generate the yaw torque includes: Get the current generator torque; The generator torque to be adjusted is determined based on the unbalanced torque difference and the current generator torque. The control parameters of the converter are adjusted based on the generator torque to be adjusted; and The generator torque is controlled and adjusted by adjusting the control parameters of the converter to generate the yaw torque.

5. The yaw control method as described in claim 1, characterized in that: The method of controlling and adjusting the generator torque and / or the wind turbine torque based on the unbalanced torque difference to generate the yaw torque of the wind turbine generator set includes: Control the current generator torque to remain within a predetermined threshold range; and The wind turbine torque is controlled and adjusted based on the unbalanced torque difference to generate the yaw torque.

6. The yaw control method as described in claim 5, characterized in that: The wind turbine generator set also includes a converter for controlling the generator, wherein controlling the current generator torque to remain within a predetermined threshold range includes: The control parameters of the converter are maintained to maintain the current generator torque.

7. The yaw control method as described in claim 5, characterized in that: The step of controlling and adjusting the wind turbine torque based on the unbalanced torque difference to generate the yaw torque includes: Obtain the current pitch angle of the wind turbine blades; The adjusted pitch angle of the blade is determined based on the unbalanced torque difference and the current pitch angle. The blades are pitched based on the pitch angle to be adjusted; and The rotor torque is controlled and adjusted by the pitch adjustment of the blades to generate the yaw torque.

8. The yaw control method as described in any one of claims 1 to 7, characterized in that: The wind turbine generator set is a direct-drive unit, in which the wind turbine is directly connected to the generator, and the unbalanced torque difference is equal to the torque difference between the wind turbine torque and the generator torque.

9. The yaw control method as described in any one of claims 1 to 7, characterized in that: The wind turbine generator set is a non-direct drive unit. The wind turbine generator set also includes a gearbox. The wind rotor and the generator are connected by transmission through the gearbox. The unbalanced torque difference is equal to the torque difference between the torque obtained by dividing the wind rotor torque by the gearbox speed ratio and the torque of the generator.

10. The yaw control method as described in claim 1, characterized in that: Also includes: Determine whether the wind turbine generator set has yawed to the correct position; After the wind turbine generator set has yawed to the desired position, the yaw mechanical brake in the wind turbine generator set is locked.

11. A yaw control system for a wind turbine generator set, characterized in that: It includes one or more processors for implementing the yaw control method for a wind turbine generator set as described in any one of claims 1-10.

12. A wind turbine generator set, characterized in that: Including the yaw control system of the wind turbine generator as described in claim 11.

13. The wind turbine generator set as described in claim 12, characterized in that: It also includes a pair of meshing bevel gears, wherein the direction of the wind turbine torque is changed to be consistent with the direction of the generator torque through the bevel gear pair.

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