Wind turbine generator set and control method

Abstract

The present invention discloses a wind turbine set and a control method, the wind turbine set comprising: a first blade group, which is a three-blade structure and fixedly mounted on one end of a wind turbine rotor; a second blade group, which is a three-blade structure and fixedly mounted on the other end of the wind turbine rotor; an independent variable pitch control unit, which independently variable pitches the first blade group and / or the second blade group according to wind speed changes and / or the power fluctuation range of the wind turbine. The present invention can effectively reduce the starting wind speed through the setting of a double blade group, and can also effectively improve the influence of turbulence on the unit. In the event of a single blade failure, the variable pitch control of the other blade group can quickly and stably achieve emergency braking, thereby improving safety.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power generation, and in particular to a wind turbine generator set and a control method suitable for the petrochemical industry. Background Art

[0002] With the continuous development of wind power technology, high-performance new wind turbines have become a hot topic in research. In particular, for the development of low wind speed areas, units with greater energy absorption are also needed. Wind turbine blades are one of the important components of wind turbines, the key to achieving energy conversion, and the key to improving the energy capture capacity of wind turbines. They are generally made of composite materials such as glass fiber and carbon fiber through a molding process. Due to the complex manufacturing process, defects are inevitable in the production process. In addition, due to the harsh working environment, variable wind speed, large differences in turbulence intensity and other complex working conditions, fatigue damage will also occur during operation. Blade problems have also become one of the biggest problems of wind turbine failures.

[0003] Chinese patent CN211573688U discloses a fan structure of a horizontal axis multi-blade wind turbine, which relates to the field of wind turbines. The fan structure includes a hub and a number of blades evenly installed on the periphery of the hub. A hollow structure is provided between adjacent blades on the hub. The hub includes a hub core and a hub panel. The hub core is fixedly arranged at the center of the hub panel. The blades are formed by laser cutting of metal as a whole and sheet metal processing is adopted. This solution makes the fan structure easy to start at low wind speeds, and at the same time has an aesthetic effect, which ensures the safe service life of the fan structure under harsh working conditions. The application of multi-blade wind turbines can significantly improve the utilization rate of wind energy and reduce the starting wind speed on the one hand, but it also brings mechanical and control problems on the other hand.

[0004] Therefore, improving the quality of wind power and expanding the wind speed range of wind turbines are important directions for future wind power development. Especially after wind power is widely connected to the power grid, petrochemical enterprises with high power supply requirements are facing new safety issues that need to be solved urgently. Therefore, there is an urgent need for a wind turbine that can reduce the starting wind speed, increase the adjustment space and improve safety, so as to increase reliability in meeting the power demand of petrochemical enterprises.

[0005] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0006] The object of the present invention is to provide a wind turbine set and a control method, which can effectively reduce the starting wind speed, improve the impact of turbulence on the set, and effectively improve the safety of the set system through the setting of a double blade group.

[0007] To achieve the above-mentioned purpose, according to a first aspect of the present invention, the present invention provides a wind turbine generator set, comprising: a first blade group, which is a three-blade structure and is fixedly installed at one end of the wind turbine rotor; a second blade group, which is a three-blade structure and is fixedly installed at the other end of the wind turbine rotor; and an independent pitch control unit, which performs independent pitch adjustment on the first blade group and / or the second blade group according to wind speed changes and / or the power fluctuation range of the wind turbine.

[0008] Furthermore, in the above technical solution, the wind turbine group also includes: a main control unit, which is communicatively connected to the independent pitch control unit, for obtaining the position information of each blade of each blade group from the independent pitch control unit, and sending pitch instructions to the independent pitch control unit according to the wind speed change and / or the power fluctuation range data of the wind turbine.

[0009] Furthermore, in the above technical solution, the independent pitch control unit includes: a position encoder, which is used to feed back the position information of the pitch to the main control unit in real time; a pitch motor, which drives the blades to rotate through gears to adjust the pitch angle; and a pitch controller, which receives pitch instructions from the main control unit and controls the operation of the pitch motor.

[0010] Furthermore, in the above technical solution, the pitch angle of the blades is adjusted in real time according to the difference between the driving torque of the first blade group and the second blade group relative to the electromagnetic torque of the wind turbine; the motion equation of the wind turbine is:

[0011]

[0012] Among them, T L1 , T L2 The driving torque provided to the first blade group and the second blade group respectively; T e is the electromagnetic torque of the wind turbine generator; J is the moment of inertia of the generator rotor; Ω is the rotational resistance coefficient; R Ω is the rotor mechanical angular velocity.

[0013] Further, in the above technical solution, independently adjusting the pitch of the first blade group and / or the second blade group according to the wind speed change may include three working modes:

[0014] First working mode: When the wind speed is less than the first preset value n N1 When , the first blade group and the second blade group work simultaneously, and both are at the maximum windward angle;

[0015] Second working mode: When the wind speed is greater than the first preset value n N1 and is less than the second preset value n N2When the first blade group is working and at the maximum windward angle, the second blade group changes the pitch to a certain angle or stops feathering according to the wind speed.

[0016] The third working mode: when the wind speed is greater than the second preset value n N2 When the first blade group and the second blade group are feathered and stopped at the same time.

[0017] Furthermore, in the above technical solution, the independent pitch adjustment of the first blade group and / or the second blade group according to the power fluctuation range of the wind turbine may be specifically performed as follows:

[0018] In the second working mode, by calculating the power fluctuation range △P of the generator, it is determined in real time whether △P is greater than the fluctuation limit threshold; when △P is greater than the fluctuation limit threshold, the first blade group and the second blade group are pitch-adjusted in turn until △P is less than or equal to the fluctuation limit threshold; if △P is still greater than the fluctuation limit threshold after the first blade group and the second blade group are pitch-adjusted in turn, the first blade group and the second blade group are simultaneously feathered and shut down.

[0019] Furthermore, in the above technical solution, the three blades of the first blade group and the three blades of the second blade group may be distributed at a spatial interval of 60°.

[0020] To achieve the above-mentioned purpose, according to the second aspect of the present invention, the present invention provides a wind turbine control method, comprising the following steps: respectively setting a first blade group and a second blade group at both ends of the rotor of the wind turbine; and independently performing pitch adjustment on the first blade group and / or the second blade group according to the wind speed change and / or the power fluctuation range of the wind turbine.

[0021] Furthermore, in the above technical solution, the position information of each blade of each blade group can be obtained in real time, and the first blade group and / or the second blade group can be independently pitch-adjusted according to the wind speed change and the power fluctuation range of the wind turbine.

[0022] Furthermore, in the above technical solution, independently adjusting the pitch of the first blade group and / or the second blade group according to the wind speed change includes three working modes:

[0023] First working mode: When the wind speed is less than the first preset value n N1 When , the first blade group and the second blade group work simultaneously, and both are at the maximum windward angle;

[0024] Second working mode: When the wind speed is greater than the first preset value n N1 and is less than the second preset value n N2 When the first blade group is working and at the maximum windward angle, the second blade group changes the pitch to a certain angle or stops feathering according to the wind speed.

[0025] The third working mode: when the wind speed is greater than the second preset value n N2 When the first blade group and the second blade group are feathered and stopped at the same time.

[0026] Furthermore, in the above technical solution, the independent pitch adjustment of the first blade group and / or the second blade group is performed according to the power fluctuation range of the wind turbine generator:

[0027] In the second working mode, by calculating the power fluctuation range △P of the generator, it is determined in real time whether △P is greater than the fluctuation limit threshold; when △P is greater than the fluctuation limit threshold, the first blade group and the second blade group are pitch-adjusted in turn until △P is less than or equal to the fluctuation limit threshold; if after the first blade group and the second blade group are pitch-adjusted in turn, △P is still greater than the fluctuation limit threshold, the first blade group and the second blade group are simultaneously feathered and shut down.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1) The setting of double blade groups can effectively reduce the starting wind speed and expand the operating space of wind turbines;

[0030] 2) The structure of two sets of blades can also effectively improve the impact of turbulence on the unit. In the event of a single blade failure, the variable pitch control of the other set of blades can quickly and stably achieve emergency braking, thereby improving safety;

[0031] 3) The present invention can adjust the pitch angle of the blades in real time and independently according to the change of wind speed, which can effectively ensure the safety of the system in areas with large wind speed fluctuations and in scenarios with high requirements for power quality such as the petrochemical industry;

[0032] 4) The present invention can also selectively perform independent pitch adjustment on the first blade group and the second blade group according to the calculation and judgment of the change of wind speed and the fluctuation range of generator power, and use the change parameters of the generator power that are relatively easy to detect for adjustment and control, which can not only ensure the rapid response of the real-time detection, calculation and comparison process, but also ensure precise adjustment, so that the generator can be controlled more accurately in situations where the wind speed fluctuates greatly; in addition, due to the use of a double-blade group structure, it is equivalent to adding a degree of freedom of adjustment, so that the output power of the generator is more stable, which can further reduce the impact of turbulence on the unit and improve the quality of electric energy.

[0033] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, and to make the above and other purposes, technical features and advantages of the present invention easier to understand, one or more preferred embodiments are listed below and described in detail with the accompanying drawings as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of the wind turbine generator set of the present invention.

[0035] Figure 2 It is a schematic diagram of the structure of the main control unit and the independent pitch control unit in the wind turbine generator set of the present invention.

[0036] Figure 3 It is a schematic diagram of the control principle of the independent pitch control unit of the present invention.

[0037] Figure 4 It is a flow chart of Embodiment 1 of the wind turbine control method of the present invention.

[0038] Figure 5 It is a flow chart of Embodiment 2 of the wind turbine control method of the present invention. DETAILED DESCRIPTION

[0039] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific implementation modes.

[0040] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising”, etc., will be understood to include the stated elements or components but not to exclude other elements or components.

[0041] In this document, for the convenience of description, spatial relative terms such as "below", "below", "down", "above", "above", "upper", etc. may be used to describe the relationship between one element or feature and another element or feature in the accompanying drawings. It should be understood that the spatial relative terms are intended to include different orientations of the object in use or operation in addition to the orientation depicted in the figure. For example, if the object in the figure is turned over, the element described as being "below" or "below" other elements or features will be oriented "above" the element or feature. Therefore, the exemplary term "below" can include both below and above. Objects may also have other orientations (rotated 90 degrees or other orientations) and the spatial relative terms used in this document should be interpreted accordingly.

[0042] In this document, the terms "first", "second", etc. are used to distinguish two different elements or parts, and are not used to limit a specific position or relative relationship. In other words, in some embodiments, the terms "first", "second", etc. can also be interchangeable.

[0043] Example 1

[0044] like Figure 1As shown, the wind turbine of the present invention adopts a double-blade group structure, including a first blade group 10, a second blade group 20 and an independent pitch control unit. The wind turbine 1 is composed of a generator stator 11 and a generator rotor 12. The generator rotor 12 is mounted in the generator stator 11 and can rotate relative to it. The first blade group 10 is fixedly mounted at one end of the wind turbine rotor 11 and is a three-blade structure. The second blade group 20 is fixedly mounted at the other end of the wind turbine rotor 12 and is also a three-blade structure. Preferably, but not restrictively, the three blades of the first blade group 10 and the three blades of the second blade group 20 are distributed at a spatial interval of 60°. The hubs corresponding to the first blade group 10 and the second blade group 20 are fixedly connected by bolts, and are completed when the unit is installed. During operation, their mechanical positions are fixed to avoid the influence of position offset. The independent pitch control unit is divided into a first independent pitch control unit 10A and a second independent pitch control unit 20A. The first independent pitch control unit 10A performs independent pitch adjustment on the first blade group according to the wind speed change and / or the power fluctuation range of the wind turbine, and the second independent pitch control unit 20A performs independent pitch adjustment on the second blade group according to the wind speed change and / or the power fluctuation range of the wind turbine.

[0045] Further Figure 1 As shown, the wind turbine of the present invention further includes a main control unit 100, which is connected in communication with the first independent pitch control unit 10A, and is used to obtain the position information of each blade from the first independent pitch control unit 10A, and send a pitch instruction to the first independent pitch control unit 10A according to the wind speed change and / or the power fluctuation range data of the wind turbine. The main control unit 100 is also connected in communication with the second independent pitch control unit 20A, and is used to obtain the position information of each blade from the second independent pitch control unit 20A, and send a pitch instruction to the second independent pitch control unit 20A according to the wind speed change and / or the power fluctuation range data of the wind turbine.

[0046] Further Figure 2 As shown, the first independent pitch control unit 10A and the second independent pitch control unit 10A respectively include their own position encoders, pitch controllers, and pitch motors. Among them, the position encoder is used to feed back the position information of the pitch to the main control unit 100 in real time. The pitch controller receives the pitch command from the main control unit 100 and controls the operation of the pitch motor. The pitch motor drives the blades of the corresponding blade group to rotate through gears to adjust the pitch angle. For the specific control principle, see Figure 3 , which is a servo control system with three closed-loop controls of position, speed and current.

[0047] The equation of motion for a wind turbine is:

[0048]

[0049] Among them, T L1 , T L2 The driving torque provided to the first blade group and the second blade group respectively; T e is the electromagnetic torque of the wind turbine generator; J is the moment of inertia of the generator rotor; Ω is the rotational resistance coefficient; R Ω is the rotor mechanical angular velocity.

[0050] From the above equation of motion, we can see that in order to reduce T L1 , T L2 and T e To avoid the risk of generator shaft damage caused by the imbalance between the two, an independent pitch control unit is required to complete the real-time adjustment of the blade pitch.

[0051] The wind turbine of the present invention adopts a structure of two sets of blade groups, which can effectively improve the influence of turbulence on the unit. In the event of a single blade failure, emergency braking can be quickly and stably achieved through the variable pitch control of the other set of blades, thereby improving safety.

[0052] Example 2

[0053] The wind turbine control method of the present invention comprises the following steps: first, a first blade group 10 and a second blade group 20 are respectively arranged at both ends of the rotor of the wind turbine; second, the first blade group 10 and / or the second blade group 20 are independently pitch-adjusted according to the wind speed change and / or the power fluctuation range of the wind turbine. Furthermore, the control method of the present invention further comprises acquiring the position information of each blade of each blade group in real time, and then independently pitch-adjusting the first blade group 10 and / or the second blade group 20 according to the wind speed change and the power fluctuation range of the wind turbine.

[0054] like Figure 4 As shown, the working process of Example 1 of the present invention is as follows:

[0055] Step S101, firstly, the wind speed detection is performed, and the generator set is in a standby state;

[0056] Step S102, when the main control unit detects that the wind speed reaches the starting wind speed, the first blade group 10 and the second blade group 20 work simultaneously, and the blades of the two blade groups are made to have the maximum windward angle through the corresponding independent pitch control unit; the real-time wind speed and the first preset value n N1 Compare: When the wind speed is less than the first preset value n N1 When the wind speed is greater than or equal to the first preset value n, the first blade group 10 and the second blade group 20 are kept working at the same time, and both are in the state of maximum windward angle; when the wind speed is greater than or equal to the first preset value n N1 When , execute step S103;

[0057] Step S103, keep the first blade group 10 working and at the maximum windward angle, control the second blade group 20 to change the pitch to a certain angle or feather the blades through the second independent pitch control unit 20A; N1 and the second preset value n N2 Compare: When the wind speed is greater than the first preset value n N1 and is less than or equal to the second preset value n N2 When the wind speed is greater than the second preset value n N2 When , step S104 is executed;

[0058] Step S104: the independent pitch control units respectively control the corresponding first blade group 10 and second blade group 20 to feather and stop simultaneously.

[0059] This embodiment 2 can adjust the pitch angle of the blades in real time and independently according to the change of wind speed, which can effectively improve the safety of the unit system in areas with large wind speed fluctuations and in scenarios with high requirements for power quality such as the petrochemical industry.

[0060] Example 3

[0061] Embodiment 3 of the present invention adds calculation and judgment of the power fluctuation range of the generator on the basis of embodiment 2, and performs pitch control on the blade group of the generator set in combination with the change of wind speed. The specific working process is as follows:

[0062] Step S201, firstly, the wind speed detection is performed, and the generator set is in a standby state;

[0063] Step S202, when the main control unit detects that the wind speed reaches the starting wind speed, the first blade group 10 and the second blade group 20 work simultaneously, and the blades of the two blade groups are made to have the maximum windward angle through the corresponding independent pitch control unit; the real-time wind speed and the first preset value n N1 Compare: When the wind speed is less than the first preset value n N1 When the wind speed is greater than or equal to the first preset value n, the first blade group 10 and the second blade group 20 are kept working at the same time, and both are in the state of maximum windward angle; when the wind speed is greater than or equal to the first preset value n N1 When , execute step S203;

[0064] Step S203, keep the first blade group 10 working and at the maximum windward angle, control the second blade group 20 to change the pitch to a certain angle or to stop the blade by the second independent pitch control unit 20A; N1 and the second preset value n N2 Compare: When the wind speed is greater than the first preset value n N1 and is less than or equal to the second preset value nN2 When the wind speed is greater than the second preset value n, step S204 is executed; when the wind speed is greater than the second preset value n N2 When the first blade group 10 and the second blade group 20 are controlled to stop feathering at the same time, step S207 is directly performed;

[0065] In step S204, the main control unit 100 calculates the power fluctuation range △P of the generator and determines in real time whether △P is greater than the fluctuation limit threshold: when the calculated △P is greater than the fluctuation limit threshold, step S205 is executed; when the calculated △P is less than or equal to the fluctuation limit threshold, the status quo is maintained and the process returns to step S204 to recalculate the power fluctuation range △P of the generator at the next set time, and so on;

[0066] Step S205, performing pitch adjustment on the first blade group to reduce power fluctuation; after a preset time interval, the main control unit 100 again compares the power fluctuation range △P of the generator with the fluctuation limit threshold, and again determines whether △P is greater than the fluctuation limit threshold: when △P is still greater than the fluctuation limit threshold, execute step S206; otherwise, it is determined that the power fluctuation has improved to a normal range, at this time, the status quo is maintained and the process returns to step S204, and the power fluctuation range △P of the generator is continuously recalculated after the next preset time interval;

[0067] Step S206, performing pitch adjustment on the second blade group to reduce power fluctuation; after a preset time interval, the main control unit 100 further compares the power fluctuation range △P of the generator with the fluctuation limit threshold, and further determines whether △P is greater than the fluctuation limit threshold: when △P is still greater than the fluctuation limit threshold after both blade groups have been pitch adjusted, it indicates that continuing to operate the wind turbine at this time will bring safety hazards, so step S207 is executed; otherwise, it is determined that the power fluctuation has improved to a normal range after the two blade groups have been independently pitch adjusted, and the status quo is maintained at this time and the process returns to step S204, and the power fluctuation range △P of the generator is recalculated after the next preset time interval;

[0068] Step S207: the main control unit 100 sends a shutdown command to the independent pitch control units, and the first independent pitch control unit 10A and the first independent pitch control unit 20A respectively control the first blade group 10 and the second blade group 20 to feather and shut down simultaneously.

[0069] This embodiment 3 selectively performs independent pitch adjustment on the first blade group and the second blade group based on the calculation and judgment of the change of wind speed and the fluctuation range of generator power, and uses the relatively easy-to-detect change parameters of the generator power for adjustment and control, which can not only ensure the rapid response of the real-time detection, calculation and comparison process, but also ensure accurate adjustment, so that the generator can still maintain stable operation in occasions with large wind speed fluctuations. In addition, since the present invention adopts a double-blade group structure, it is equivalent to adding a degree of freedom of adjustment, making the generator output power more stable, which can further reduce the impact of turbulence on the unit and improve the quality of power.

[0070] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. Any simple modifications, equivalent changes and modifications made to the above exemplary embodiments should fall within the scope of protection of the present invention.

Claims

1. A wind turbine generator set, characterized in that: include: The first blade group is a three-blade structure and is fixedly mounted on one end of the wind turbine rotor; A second blade group, which is a three-blade structure and is fixedly mounted on the other end of the wind turbine rotor; An independent pitch control unit, which performs independent pitch adjustment on the first blade group and / or the second blade group according to wind speed changes and / or power fluctuation range of the wind turbine; The independent pitch adjustment of the first blade group and / or the second blade group according to the wind speed change includes three working modes, wherein the second working mode is: when the wind speed is greater than the first preset value n N1 and is less than the second preset value n N2 When the first blade group is in operation and at the maximum windward angle, the second blade group changes its pitch to a certain angle or stops feathering according to the wind speed; The independent pitch adjustment of the first blade group and / or the second blade group according to the power fluctuation range of the wind turbine generator is specifically as follows: in the second working mode, by calculating the power fluctuation range ΔP of the generator, determining in real time whether the ΔP is greater than the fluctuation limit threshold; When the △P is greater than the fluctuation limit threshold, the first blade group and the second blade group are pitch-adjusted in sequence until the △P is less than or equal to the fluctuation limit threshold; if the first blade group and the second blade group are pitch-adjusted in sequence and the △P is still greater than the fluctuation limit threshold, the first blade group and the second blade group are simultaneously feathered and shut down.

2. The wind turbine generator set according to claim 1, characterized in that: Also includes: A main control unit is communicatively connected with the independent pitch control unit, and is used for obtaining position information of each blade of each blade group from the independent pitch control unit, and sending a pitch instruction to the independent pitch control unit according to wind speed changes and / or power fluctuation range data of the wind turbine.

3. The wind turbine generator set according to claim 2, characterized in that: The independent pitch control unit comprises: A position encoder, which is used to feed back position information of the variable pitch to the main control unit in real time; A pitch motor drives the blades to rotate through gears to adjust the pitch angle; A pitch controller receives the pitch instruction from the main control unit and controls the operation of the pitch motor.

4. The wind turbine generator set according to claim 1, characterized in that: The pitch angle of the blades is adjusted in real time according to the difference between the driving torque of the first blade group and the second blade group relative to the electromagnetic torque of the wind generator; the motion equation of the wind generator is: Among them, T L1 , T L2 The driving torque provided to the first blade group and the second blade group respectively; T e is the electromagnetic torque of the wind turbine generator; J is the moment of inertia of the generator rotor; Ω is the rotational resistance coefficient; R Ω is the rotor mechanical angular velocity.

5. The wind turbine generator set according to claim 1, characterized in that: The three working modes also include: First working mode: when the wind speed is less than the first preset value n N1 When the first blade group and the second blade group work simultaneously, both of them are at the maximum windward angle; The third working mode: when the wind speed is greater than the second preset value n N2 When the first blade group and the second blade group are feathered and stopped at the same time.

6. The wind turbine generator set according to claim 1, characterized in that: The three blades of the first blade group and the three blades of the second blade group are distributed at a spatial interval of 60°.

7. A wind turbine control method, characterized in that: The steps include: A first blade group and a second blade group are respectively arranged at two ends of the rotor of the wind turbine; performing independent pitch adjustment on the first blade group and / or the second blade group respectively according to the wind speed change and / or the power fluctuation range of the wind turbine; The independent pitch adjustment of the first blade group and / or the second blade group according to the wind speed change includes three working modes, wherein the second working mode is: when the wind speed is greater than the first preset value n N1 and is less than the second preset value n N2 When the first blade group is in operation and at the maximum windward angle, the second blade group changes its pitch to a certain angle or stops feathering according to the wind speed; The specific steps of independently performing pitch adjustment on the first blade group and / or the second blade group according to the power fluctuation range of the wind turbine are as follows: in the second working mode, by calculating the power fluctuation range △P of the generator, it is determined in real time whether the △P is greater than the fluctuation limit threshold; when the △P is greater than the fluctuation limit threshold, the first blade group and the second blade group are pitch adjusted in turn until the △P is less than or equal to the fluctuation limit threshold; if after the first blade group and the second blade group are pitch adjusted in turn, the △P is still greater than the fluctuation limit threshold, the first blade group and the second blade group are simultaneously feathered and shut down.

8. The wind turbine control method according to claim 7, characterized in that: By acquiring the position information of each blade of each blade group in real time, the first blade group and / or the second blade group are independently pitch-adjusted according to the wind speed change and the power fluctuation range of the wind turbine.

9. The wind turbine control method according to claim 8, characterized in that: The three working modes also include: First working mode: when the wind speed is less than the first preset value n N1 When the first blade group and the second blade group work simultaneously, both of them are at the maximum windward angle; The third working mode: when the wind speed is greater than the second preset value n N2 When the first blade group and the second blade group are feathered and stopped at the same time.

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