A microwave anti-icing device and method for wind turbine blades

Abstract

The present invention discloses a microwave anti-icing device and method for wind turbine blades, which belongs to the field of wind power generation technology and can solve the problems of limited anti-icing efficiency, low durability, and certain safety hazards of existing anti-icing technologies. The device includes: a first microwave generator, which is arranged on the inner cavity wall of the wind turbine blade, and its microwave emitting end faces the leading edge of the blade; a second microwave generator, which is arranged on the outer wall of the wind turbine tower, and its microwave emitting end faces the blade of the wind turbine; a third microwave generator, which is arranged directly below the swept surface of the blade, and its microwave emitting end faces the tip of the wind turbine blade; a microwave control and signal transmission unit, which is used to control each microwave generator to emit microwaves to the blades of the wind turbine for deicing according to different working conditions of the wind turbine without affecting the energy efficiency output of the unit. The present invention provides a new method and idea for the current winter and spring anti-icing project of wind turbine blades.

Description

Technical Field

[0001] The invention relates to a microwave anti-icing device and method for wind turbine blades, belonging to the technical field of wind power generation. Background Art

[0002] As a key component of wind turbine energy capture, wind turbine blades have a unique aerodynamic shape. When air flows through them, they generate optimal lift, causing the impeller to rotate, which in turn drives the generator to convert wind energy into electrical energy. During the winter and spring seasons, when wind turbines are operating at zero degrees Celsius or below, if they encounter humid air, rain, salt spray, ice and snow, and freezing rain, blade ice will occur. After the blades are covered with ice, the changes in the local geometric airfoil of the blades will cause changes in their aerodynamic characteristics, often reducing their aerodynamic efficiency and affecting the power generation performance of the wind turbine. At the same time, the blades covered with ice will cause uneven load distribution, resulting in unbalanced rotation and abnormal vibration of the impeller. When the ice is severely covered, the increase in the dynamic load of the blades will also cause overload shutdown, which will have an adverse effect on the safety performance of the wind turbine.

[0003] Under the influence of multiple factors such as the local climate environment and terrain conditions in the area where the wind farm is located, wind turbine blades will form ice of different textures and shapes under different working conditions. The ice-covering process and characteristics of wind turbine blades in different regions are very different, and the corresponding de-icing technical measures are also different. At present, the commonly used anti-icing and de-icing technologies for wind turbine blades are mainly mechanical de-icing, blade surface coating anti-icing, blade cavity hot air heating anti-icing, and blade surface electric heating film anti-icing. Among them, mechanical deicing is suitable for situations where ice is seriously covered. The ice is broken up by mechanical methods and then blown away by airflow. It is characterized by low operating costs, but low deicing efficiency and high work intensity; blade surface coating anti-icing is achieved by coating anti-icing coating on the surface of the blade substrate to reduce the adhesion of ice to the substrate surface and the amount of ice covering the surface, and then using the effects of wind and gravity to make it easier for the ice to fall off the substrate surface. It is characterized by simplicity and low cost, but limited anti-icing effect. Due to long-term exposure to the natural environment, its durability is not high and maintenance is required after a certain number of years; blade cavity hot air blast heating anti-icing is to install a blower, heating pipe and heat circulation pipe at the root of the blade cavity It is said that by transporting high-pressure hot air to the inside of the blade to form a heat cycle, the surface temperature of the blade is increased based on heat conduction to achieve the purpose of anti-icing and de-icing. Its characteristics are uniform heating effect and no effect on aerodynamic performance. However, due to the low thermal conductivity of the fiberglass matrix of the blade, its energy consumption is extremely high and the de-icing efficiency is low. The electric heating film on the surface of the blade is used to prevent and de-ice. An electric heating unit is laid on the blade, which is directly integrated with the prepreg and protected inside the wind turbine blade. The surface electrical components and metal devices on the fuselage are powered on for heating to quickly de-ice the surface. It is characterized by high heating efficiency, but the burial of the conductive film will greatly increase the risk of the blade being struck by lightning, and there are certain safety hazards. Summary of the invention

[0004] The present invention provides a microwave anti-icing device and method for wind turbine blades, which can solve the problems of low anti-icing efficiency and certain safety hazards in existing anti-icing technologies.

[0005] In one aspect, the present invention provides a microwave anti-icing device for wind turbine blades, the device comprising:

[0006] A first microwave generator is arranged on the inner cavity wall of the wind turbine blade, and its microwave emitting end faces the leading edge of the blade;

[0007] The microwave control unit is arranged on the wind turbine and is electrically connected to the first microwave generator, and is used for controlling the first microwave generator to emit microwaves to the blades of the wind turbine.

[0008] Optionally, the device further comprises:

[0009] A second microwave generator is arranged on the outer side wall of the wind turbine tower, and its microwave emitting end faces the blades of the wind turbine;

[0010] The microwave control unit is electrically connected to the second microwave generator and is used to control the second microwave generator to emit microwaves to the blades of the wind turbine.

[0011] Optionally, the device further comprises:

[0012] A third microwave generator is arranged directly below the blade sweep surface, and its microwave emitting end faces the blade tip of the wind turbine;

[0013] The microwave control unit is electrically connected to the third microwave generator and is used to control the third microwave generator to emit microwaves to the blades of the wind turbine.

[0014] Optionally, the microwave control unit includes a first control subunit and a second control subunit;

[0015] The first control subunit is disposed in the nacelle of the wind turbine and is electrically connected to the first microwave generator and the second microwave generator, and is used to provide electric energy and control signals to the first microwave generator and the second microwave generator;

[0016] The second control subunit is disposed at the bottom of the wind turbine tower and is electrically connected to the third microwave generator, and is used for providing electrical energy and control signals to the third microwave generator.

[0017] Optionally, the first microwave generator is arranged on the inner cavity wall of the leading edge of the blade, and extends from the root position of the blade to the tip position of the blade.

[0018] Optionally, the second microwave generator is extended downward from the bottom of the nacelle, and its extension length is greater than or equal to the length of the blade.

[0019] Optionally, the device further comprises:

[0020] A signal conduction unit is electrically connected between the first control subunit and the first microwave generator, and is used for transmitting the electric energy and the control signal provided by the first control subunit to the first microwave generator.

[0021] Optionally, the signal transmission unit includes:

[0022] A conductive slip ring is connected to the nacelle of the wind turbine, and its central axis coincides with the central axis of the hub of the wind turbine; the conductive slip ring is electrically connected to the first control subunit;

[0023] A plurality of brushes are fixed on the hub at intervals and correspond to the blades one by one; one side of the brush contacts the conductive slip ring, and the other side is electrically connected to the first microwave generator in the corresponding blade.

[0024] On the other hand, the present invention provides a microwave anti-icing method applied to any of the microwave anti-icing devices described above, when the wind turbine is in a shutdown state, the method comprises:

[0025] S91, adjusting the blades to be deiced of the wind turbine to rotate to a position parallel to the wind turbine tower, so that the blades to be deiced are directly opposite to the position of the second microwave generator;

[0026] S92, adjusting the leading edge of the blade to be de-iced to face toward the second microwave generator;

[0027] S93, placing a third microwave generator directly below the blade to be de-iced;

[0028] S94. After receiving the start signal, the microwave control unit controls the first microwave generator, the second microwave generator and the third microwave generator to emit microwaves to the blade to be de-iced.

[0029] In another aspect, the present invention provides a microwave anti-icing method applied to any of the microwave anti-icing devices described above, when the wind turbine is in operation, the method comprising:

[0030] S101, the monitoring system monitors the icing degree of the blades of the wind turbine in real time, and sends a start signal when the icing degree of the blades meets a preset condition;

[0031] S102: After receiving the start signal, the microwave control unit controls the first microwave generator, the second microwave generator, and the third microwave generator to emit microwaves to the blades of the wind turbine.

[0032] The beneficial effects that the present invention can produce include:

[0033] (1) The microwave anti-icing device for wind turbine blades provided by the present invention uses microwaves generated by a microwave generator to act on the blade receptor to heat the blade, thereby reducing the interfacial adhesion of the ice layer on the blade. The ice then falls off the blade under the centrifugal force of gravity or the rotation of the impeller, thereby effectively removing ice. Since this method does not require any modification to the outer surface of the blade, it will not change the aerodynamic shape of the blade, thereby avoiding the impact on the aerodynamic performance and load of the blade. In addition, during the entire process of using microwaves to remove ice from wind turbine blades, under the premise of ensuring microwave radiation protection, there is no harm to the surrounding environment. It is a new type of blade deicing technology that is efficient, harmless, green and safe.

[0034] (2) The microwave anti-icing device for wind turbine blades provided by the present invention, during the targeted microwave heating process, the microwave energy will only be absorbed by the ice-covered blade substrate, and the ambient air will not absorb the microwave energy, so the utilization rate of the microwave energy is very high, and the heating efficiency will be correspondingly improved; secondly, the penetration of microwaves can penetrate the ice layer directly to the surface of the blade substrate, and in this process, the ice layer will not absorb heat and melt. This feature can avoid consuming a large amount of heat and thus reduce the cost of deicing. Compared with other thermal deicing methods that require a large amount of heat to remove the surface ice layer, the energy consumption of microwave deicing is relatively low.

[0035] (3) The microwave anti-icing device for wind turbine blades provided by the present invention can simultaneously realize the supply of microwave power and control signals during the anti-icing process of the wind turbine in both the working (rotating impeller) and non-working (stationary) states by setting a rotating signal transmission unit composed of a conductive slip ring and a brush, thereby effectively preventing the wires connected to the inner cavities of the three blades from being entangled when the impeller rotates, avoiding special shutdown for deicing operations, and not affecting the normal energy efficiency output of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of the overall structure of a microwave anti-icing device for wind turbine blades provided in an embodiment of the present invention;

[0037] Figure 2 A schematic diagram of the installation structure of a first microwave generator built into a blade substrate in an inner cavity of a wind turbine blade provided by an embodiment of the present invention;

[0038] Figure 3 A schematic diagram of the structure of a rotary signal transmission unit provided by an embodiment of the present invention;

[0039] Figure 4 This is a working principle diagram of the microwave anti-icing device provided in an embodiment of the present invention.

[0040] List of parts and reference numerals:

[0041] 11. First microwave generator; 12. Second microwave generator; 13. Third microwave generator; 14. Blade; 15. Tower; 16. Nacelle; 17. First control subunit; 18. Second control subunit; 19. Blade leading edge; 20. Blade trailing edge; 21. Blade base; 22. Inner cavity wall; 23. Conductive slip ring; 24. Brush; 25. Hub. DETAILED DESCRIPTION

[0042] The present invention is described in detail below in conjunction with embodiments, but the present invention is not limited to these embodiments.

[0043] The embodiment of the present invention provides a microwave anti-icing device for wind turbine blades, such as Figures 1 to 3As shown, the device comprises:

[0044] The first microwave generator 11 is arranged on the inner cavity wall 22 of the wind turbine blade 14, and its microwave emitting end faces the blade leading edge 19. Specifically, the first microwave generator 11 is arranged on the inner cavity wall 22 of the blade leading edge 19, and extends from the root of the blade 14 to the tip of the blade.

[0045] refer to Figure 2 As shown, the blade 14 of the wind turbine includes a blade base 21, and the blade base 21 has a hollow cavity structure; the blade base 21 includes a blade leading edge 19 and a blade trailing edge 20 that are located opposite to each other; the first microwave generator 11 is arranged on the inner cavity wall 22 of the blade leading edge 19. The blade leading edge 19 is usually a part that is easy to freeze, so the first microwave generator 11 built into the blade base 21 can be installed on the inner cavity wall 22 along the blade leading edge 19 of the wind turbine, starting from the blade root and extending to the blade tip, so that the first microwave generator 11 can directly perform microwave de-icing on the blade leading edge 19.

[0046] Furthermore, the device also includes:

[0047] The second microwave generator 12 is arranged on the outer side wall of the wind turbine tower 15 , and its microwave emitting end faces the blades 14 of the wind turbine; specifically, the second microwave generator 12 extends downward from the bottom of the nacelle 16 , and its extension length is greater than or equal to the length of the blades 14 .

[0048] refer to Figure 1 As shown, the second microwave generator 12 is installed on the outside of the wind turbine tower 15, starting from the outer bottom of the wind turbine nacelle 16 and extending to the lower middle part of the tower 15, and its length is slightly greater than the length of the wind turbine blade 14, ensuring that when the wind turbine blade 14 is aligned parallel to the wind turbine tower 15, the second microwave generator 12 externally mounted on the tower 15 can cover the entire length of the wind turbine blade 14.

[0049] Preferably, the device further comprises:

[0050] The third microwave generator 13 is arranged just below the swept surface of the blade 14, and its microwave emitting end faces the tip of the blade 14 of the wind turbine.

[0051] refer to Figure 1 As shown, the third microwave generator 13 is an external box-type microwave generator, which is a movable device, usually placed just below the swept surface of the wind turbine blade 14, and can emit microwaves vertically upward.

[0052] The device also includes: a microwave control unit, which is arranged on the wind turbine and is electrically connected to the first microwave generator 11, the second microwave generator 12 and the third microwave generator 13, and is used to control the first microwave generator 11, the second microwave generator 12 and the third microwave generator 13 to emit microwaves to the blades 14 of the wind turbine.

[0053] In practical applications, the microwave control unit may include a first control subunit 17 and a second control subunit 18; the first control subunit 17 is disposed in the nacelle 16 of the wind turbine and is electrically connected to the first microwave generator 11 and the second microwave generator 12, and is used to provide power and control signals to the first microwave generator 11 and the second microwave generator 12; the second control subunit 18 is disposed at the bottom of the wind turbine tower 15 and is electrically connected to the third microwave generator 13, and is used to provide power and control signals to the third microwave generator 13. The control signal can control the opening and closing of each microwave generator, and can also control the microwave power emitted by each microwave generator.

[0054] refer to Figure 1 As shown, the first control subunit 17 is located inside the wind turbine nacelle 16, obtains control signals and electric energy from the wind turbine main control system and the power box in the nacelle 16, and provides electric energy and control signals to the first microwave generator 11 and the second microwave generator 12 through the electrical transmission line. The second control subunit 18 is located at the bottom of the tower 15, and provides electric energy and control signals to the third microwave generator 13 through the electrical transmission line.

[0055] In an embodiment of the present invention, the device further includes:

[0056] The signal transmission unit is electrically connected between the first control subunit 17 and the first microwave generator 11 , and is used for transmitting the electric energy and the control signal provided by the first control subunit 17 to the first microwave generator 11 .

[0057] Specifically, refer to Figure 3 As shown, the signal transduction unit includes:

[0058] The conductive slip ring 23 is connected to the nacelle 16 of the wind turbine, and its central axis coincides with the central axis of the hub 25 of the wind turbine; the conductive slip ring 23 is electrically connected to the first control subunit 17;

[0059] A plurality of brushes 24 are fixed on the hub 25 at intervals and correspond to the blades 14 one by one. One side of the brush 24 contacts the conductive slip ring 23 , and the other side is electrically connected to the first microwave generator 11 in the corresponding blade 14 .

[0060] The first microwave generator 11 is connected to the brush 24 corresponding to the blade 14 through the electrical transmission line. The brush 24 is fixed on the hub 25 and rotates with the blade 14 and the hub 25 of the wind turbine. The inner side of the brush 24 contacts the conductive slip ring 23. The conductive slip ring 23 is connected to the nacelle 16 and is fixed and non-rotating. It is used to transmit electric energy and control signals to the brush 24 that contacts and rotates. The rotating signal transmission unit composed of the brush 24 corresponding to the three blades 14 and the conductive slip ring 23 can effectively avoid the entanglement of the transmission line in the hub 25 caused by the rotation of the impeller.

[0061] The embodiment of the present invention does not limit the types of the first microwave generator 11, the second microwave generator 12 and the third microwave generator 13, and those skilled in the art can select them according to actual conditions. In practical applications, the first microwave generator 11, the second microwave generator 12 and the third microwave generator 13 can all be magnetrons, which are microwave electron tubes. The magnetron is a reentrant resonant orthogonal field oscillator that can generate high-power microwaves with a frequency of gigahertz, which is suitable for microwave heating in outdoor environments. At the same time, the radiation energy of the above three microwave generators can be adjusted to ensure the deicing effect under different working conditions and icing degrees.

[0062] The present invention uses microwaves generated by a microwave generator to act on the blade 14 receptor to heat the blade 14, so that the interfacial adhesion of the ice layer on the blade 14 decreases, and then the ice falls off the blade 14 under the centrifugal effect of gravity or impeller rotation, thereby effectively removing ice; since this method does not require any modification of the outer surface of the blade 14, it will not change the aerodynamic shape of the blade 14, thus avoiding the impact on the aerodynamic performance and load of the blade 14. In addition, in the whole process of removing ice from the wind turbine blade 14 by microwaves, under the premise of good microwave radiation protection, there is no harm to the surrounding environment, which is a new type of blade 14 deicing technology that is efficient, harmless, green and safe.

[0063] In the targeted microwave heating process of the present invention, microwave energy will only be absorbed by the ice-covered blade 14 substrate, and the ambient air will not absorb microwave energy, so the utilization rate of microwave energy is very high, and the heating efficiency will be improved accordingly; secondly, the penetration of microwaves can directly reach the surface of the blade 14 substrate through the ice layer, and in this process, the ice layer will not absorb heat and melt. This feature can avoid consuming a large amount of heat and thus reduce the cost of deicing. Compared with other thermal deicing methods that require a large amount of heat to remove the surface ice layer, the energy consumption of microwave deicing is relatively low.

[0064] The present invention provides a rotating signal transmission unit composed of a conductive slip ring 23 and a brush 24, thereby simultaneously realizing the supply of electric energy and control signals required by microwaves during the de-icing process of the wind turbine in both the working (rotating impeller) and non-working (stationary) states, effectively preventing the wires connected to the inner cavities of the three blades 14 from being entangled when the impeller rotates, avoiding special shutdown for de-icing operations, and not affecting the normal energy efficiency output of the unit.

[0065] Another embodiment of the present invention provides a microwave anti-icing method applied to any of the microwave anti-icing devices described above, such as Figure 4 As shown, when the wind turbine is in a shutdown state, the method includes:

[0066] S91, adjusting the blades 14 of the wind turbine to be deiced to rotate to a position parallel to the wind turbine tower 15, so that the blades 14 to be deiced are directly opposite to the second microwave generator 12;

[0067] S92, adjusting the leading edge 19 of the blade 14 to be de-iced toward the second microwave generator 12;

[0068] S93, placing the third microwave generator 13 directly below the blade 14 to be de-iced;

[0069] S94. After receiving the start signal, the microwave control unit controls the first microwave generator 11, the second microwave generator 12 and the third microwave generator 13 to emit microwaves to the blade 14 to be de-iced.

[0070] refer to Figure 4 As shown, when the wind turbine blade 14 is in a non-working state (i.e., in a shutdown state, the impeller is not rotating) and is obviously covered with ice, firstly, the target wind turbine blade (i.e., the blade 14 to be deiced) is rotated and adjusted to a parallel position adjacent to the tower 15 in the air through active control, so that the blade 14 to be deiced is facing the second microwave generator 12 outside the tower 15 base, and at the same time, the blade 14 pitch system is controlled to make the leading edge 19 of the blade face the second microwave generator 12; secondly, the external box-type third microwave generator 13 is placed directly below the blade 14 to be deiced, so that its microwave emitting end is facing the tip direction of the blade 14 to be deiced, and is connected to draw power through the power box (i.e., the second control subunit 18) at the bottom of the tower 15.

[0071] Subsequently, the wind farm operation and maintenance staff sends a start signal to the first control subunit 17 in the nacelle 16. The first control subunit 17 in the nacelle 16 controls the first microwave generator 11 built into the base of the blade 14 to start up through the conductive slip ring 23 and the brush 24. The first microwave generator 11 performs microwave heating on the base at the leading edge 19 of the blade. At the same time, the first control subunit 17 in the nacelle 16 also sends a start signal to the second microwave generator 12 outside the base of the tower 15. The second microwave generator 12 emits microwaves in the direction of the blade 14 to be deiced, and heats the entire blade leading edge 19 area. At the same time, the external box-type third microwave generator 13 also starts to emit microwaves to the tip of the blade 14 to be deiced, and heats the entire blade 14 upward along the tip.

[0072] At this time, the blade 14 to be de-iced is continuously heated by microwaves from three microwave generators: the leading edge inner cavity wall 22, the outer side of the tower 15, and directly below the blade 14. The base of the blade 14 is heated as a whole, and the ice layer in contact with the surface of the blade 14 begins to melt, which reduces the adhesion of the ice layer on the blade 14. Then, the ice falls off the blade 14 under the action of gravity, thereby completing the entire de-icing process.

[0073] After the deicing process of the first blade 14 is completed, the second and third ice-covered blades 14 can also be rotated and adjusted to parallel positions adjacent to the tower 15 in the air through active control, and the deicing operation can be performed using the above method.

[0074] Furthermore, when the wind turbine is in operation, the microwave anti-icing method includes:

[0075] S101. The monitoring system monitors the ice degree of the wind turbine blades 14 in real time, and sends a start signal when the ice degree of the blades 14 meets a preset condition; wherein the preset condition is a condition pre-set by a technician in this field according to actual conditions, and the embodiment of the present invention does not limit this.

[0076] S102 , after receiving the start signal, the microwave control unit controls the first microwave generator 11 , the second microwave generator 12 and the third microwave generator 13 to emit microwaves to the blades 14 of the wind turbine.

[0077] refer to Figure 4As shown, when the wind turbine generator set is in working state (rotating impeller), icing occurs. The Supervisory Control And Data Acquisition (SCADA) system (usually a standard factory configuration) equipped by the unit itself, which can also be referred to as the monitoring system, sends a freezing warning to the wind farm station centralized control and operation center. At this time, the wind farm operation and maintenance staff sends a start signal to the first control subunit 17 in the cabin 16; or when the monitoring system monitors that the degree of icing on the blade 14 of the wind turbine meets the preset conditions, it directly sends a start signal to the first control subunit 17, and the first control subunit 17 controls the first microwave generator 11 built into the base of the blade 14 to start through the conductive slip ring 23 and the brush 24. Since the first microwave generator 11 built into the blade 14 matrix at the inner cavity of each wind turbine blade 14 is connected to the corresponding brush 24, and the brush 24 is fixed on the hub 25, the hub 25 is driven to rotate when the blade 14 rotates, and the brush 24 rotates synchronously with the hub 25; the conductive slip ring 23 is fixed on the inner side of the brush 24 and contacts the brushes 24 corresponding to the three blades 14, but it does not rotate itself. Its main function is to transmit electrical energy and control signals to each brush 24, thereby solving the problem of wire entanglement when the impeller composed of three blades 14 rotates. After the first microwave generator 11 built into the base of the blade 14 receives the electric energy and control signal transmitted to the brush 24 through the conductive slip ring 23, it starts to perform microwave heating on the base (usually made of fiberglass) at the leading edge of the blade 14; at the same time, the first control subunit 17 also sends a start signal to the second microwave generator 12 built outside the base of the tower 15, and the second microwave generator 12 emits high-power microwaves in front of it. When the wind turbine blade 14 rotates and sweeps to the area below the wind rotor surface and close to the wind turbine tower 15, it is affected by the microwaves emitted by the second microwave generator 12 and starts to generate heat periodically based on the rotation speed of the impeller; at this time, according to actual needs, the external box-type third microwave generator 13 can also be placed on the ground at the bottom of the impeller swept surface, and the microwave output power is increased, so that when the wind turbine blade 14 rotates to the area below the wind rotor swept surface, it receives the microwave action and then generates heat periodically with a certain gradient from the tip to the root of the blade.

[0078] At this time, under the combined effect of continuous heating by the first microwave generator 11 and high-power periodic heating by the second microwave generator 12 (and the third microwave generator 13), the base of all wind turbine blades 14 is heated up as a whole, and the ice layer in contact with the surface of the blade 14 begins to melt, so that the adhesion of the ice layer on the blade 14 decreases, and then the ice is thrown off the blade 14 under the combined effect of gravity and centrifugal force, thereby completing the anti-icing process under the rotating state of the impeller.

[0079] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A microwave anti-icing device for wind turbine blades, characterized in that: The device comprises: A first microwave generator is arranged on the inner cavity wall of the wind turbine blade, and its microwave emitting end faces the leading edge of the blade; the first microwave generator is arranged on the inner cavity wall of the leading edge of the blade, and it extends from the root of the blade to the tip of the blade; A third microwave generator is arranged directly below the blade sweep surface, and its microwave emitting end faces the blade tip of the wind turbine; a microwave control unit, which is arranged on the wind turbine and is electrically connected to the first microwave generator and the third microwave generator, and is used to control the first microwave generator and the third microwave generator to transmit microwaves to the blades of the wind turbine; the microwave control unit includes a first control subunit; the first control subunit is arranged in the nacelle of the wind turbine and is electrically connected to the first microwave generator, and is used to provide electric energy and control signals to the first microwave generator; A signal transmission unit comprises a conductive slip ring and a plurality of brushes, wherein the conductive slip ring is connected to a nacelle of a wind turbine, and a central axis thereof coincides with a central axis of a hub of the wind turbine; the conductive slip ring is electrically connected to the first control subunit; a plurality of brushes are fixed on the hub at intervals and correspond to blades one by one; one side of the brush contacts the conductive slip ring, and the other side is electrically connected to a first microwave generator in a corresponding blade.

2. The device according to claim 1, characterized in that The device also includes: A second microwave generator is arranged on the outer side wall of the wind turbine tower, and its microwave emitting end faces the blades of the wind turbine; The microwave control unit is electrically connected to the second microwave generator and is used to control the second microwave generator to emit microwaves to the blades of the wind turbine.

3. The device according to claim 2, characterized in that The microwave control unit also includes a second control subunit; The first control subunit is also electrically connected to the second microwave generator, and is used to provide electrical energy and control signals to the second microwave generator; The second control subunit is disposed at the bottom of the wind turbine tower and is electrically connected to the third microwave generator, and is used for providing electrical energy and control signals to the third microwave generator.

4. The device according to claim 2, characterized in that The second microwave generator is extended downward from the bottom of the nacelle, and the extension length thereof is greater than or equal to the length of the blade.

5. A microwave anti-icing method applied to the microwave anti-icing device according to any one of claims 2 to 4, characterized in that: When the wind turbine is in a shutdown state, the method includes: S91, adjusting the blades to be deiced of the wind turbine to rotate to a position parallel to the wind turbine tower, so that the blades to be deiced are directly opposite to the position of the second microwave generator; S92, adjusting the leading edge of the blade to be de-iced to face toward the second microwave generator; S93, placing a third microwave generator directly below the blade to be de-iced; S94. After receiving the start signal, the microwave control unit controls the first microwave generator, the second microwave generator and the third microwave generator to emit microwaves to the blade to be de-iced.

6. A microwave anti-icing method applied to the microwave anti-icing device according to any one of claims 2 to 4, characterized in that: When the wind turbine is in operation, the method comprises: S101, the monitoring system monitors the icing degree of the blades of the wind turbine in real time, and sends a start signal when the icing degree of the blades meets a preset condition; S102: After receiving the start signal, the microwave control unit controls the first microwave generator, the second microwave generator, and the third microwave generator to emit microwaves to the blades of the wind turbine.

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