A filtering and dust-removing system and control method of a wind power generator

Abstract

The application discloses a filtering and dust removing system and a control method of a wind driven generator, and belongs to the technical field of wind driven power generation. The system comprises a machine base, a generator winding is arranged in the machine base, and at least one set of first filtering devices are arranged on the machine base; a cooling assembly comprises a cooling shell arranged on the machine base, a cooling fan and second filtering devices arranged in the cooling shell, and an air inlet and outlet are arranged on the side, away from the machine base, of the cooling shell, and the cooling fan adopts a reversible axial flow fan; a control unit is arranged to control the filtering and dust removing system to switch between a cooling mode and a dust removing mode; in the cooling mode, the cooling fan is controlled to rotate in a forward direction, external air enters the machine base through the first filtering devices and is discharged along the air inlet and outlet of the cooling shell; and in the dust removing mode, the cooling fan is controlled to rotate in a reverse direction, external air enters the machine base through the air inlet and outlet of the cooling shell and is discharged along the first filtering devices of the machine base.

Description

Technical Field

[0001] This invention relates to the field of wind turbines, and in particular to a dust removal and filtration structure and control method for wind turbines. Background Technology

[0002] Doubly-fed induction generators (DFIGs) have long been one of the mainstream technologies in wind power generation. Their stator windings are directly connected to the grid, while the rotor windings are connected via back-to-back converters. This allows the generator to operate at variable speeds within a certain range above and below its rated speed, thus capturing wind energy more efficiently and providing some reactive power support and fault ride-through capability to the grid. Wind turbines generate a large amount of heat during operation. If this heat is not dissipated effectively and promptly, it can cause a rapid increase in the internal temperature of the generator. Currently, DFIGs typically employ an open-type direct cooling method, where cooling air is drawn directly from the external environment, pressurized by an internal cooling fan, and forced to flow through heat-generating components inside the generator, such as the ends of the rotor windings and the stator core ventilation ducts, directly carrying away heat before being directly discharged back to the external environment.

[0003] The biggest impact of open-type direct cooling on generators is the severe reduction in protection levels, especially as impurities and dust from the outside air can easily enter the generator, significantly affecting insulation and creepage distances between internal components. To address this issue, current generators typically incorporate filters at the air inlet to remove dust, lint, and other impurities. However, these inlet filters are disposable and need replacement every six months to a year. In harsh wind environments with sandstorms or dust storms, replacement is even more frequent; otherwise, the filters become severely clogged with dust and lint, leading to insufficient airflow, reduced cooling efficiency, and ultimately, overheating of the generator windings and shutdown, limiting the unit's effective power generation time. Furthermore, for safety reasons, maintenance personnel cannot access the tower to clean or replace filters during high winds. If a clogged filter causes a high-temperature shutdown of the generator windings, the unit cannot operate, severely impacting power generation. Therefore, providing a method for accurately assessing filter clogging and efficiently removing dust from the filters is a crucial technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0004] Therefore, this invention proposes a filtration and dust removal system and control method for wind turbine generators, which can automatically and efficiently remove dust from the filter screen of wind turbine generator sets.

[0005] To address the aforementioned technical problems, the present invention provides the following technical solution:

[0006] A dust removal and filtration system for a wind turbine includes: a base, inside which generator windings are installed, and at least one set of first filtration devices are provided on the base; a cooling assembly, including: a cooling housing mounted on the base, and a cooling fan and a second filtration device mounted inside the cooling housing, wherein the cooling housing has an air inlet and outlet on the side away from the base, and the cooling fan is a reversible axial flow fan; and a control unit, which controls the dust removal and filtration system to switch between a cooling mode and a dust removal mode; in the cooling mode, the cooling fan is controlled to rotate forward, and external air enters the base through the first filtration device and is discharged along the air inlet and outlet of the cooling housing; in the dust removal mode, the cooling fan is controlled to rotate in reverse, and external air enters the base through the air inlet and outlet of the cooling housing and is discharged along the first filtration device of the base.

[0007] In some embodiments of the present invention, the wind turbine is a doubly fed induction generator, and in dust removal mode, the control unit controls the transmission chain of the wind turbine to reverse.

[0008] In some embodiments of the present invention, the generator winding includes a stator winding and a rotor winding, the rotor winding is mounted on a rotor shaft, and the cooling assembly further includes at least one set of coaxial fans connected to the rotor shaft, the coaxial fans rotating synchronously with the rotor winding.

[0009] In some embodiments of the present invention, the cooling housing includes an air guide duct extending in the same direction as the rotor shaft, and the cooling fan and the second filter device are installed inside the air guide duct.

[0010] In some embodiments of the present invention, the second filter device is an electrically operated louvered filter device. In cooling mode, the second filter device is controlled to be in a state where the air inlet and outlet are fully open; in dust removal mode, the second filter device is controlled to be in a state where the air inlet and outlet are at least partially blocked.

[0011] In some embodiments of the present invention, a dust concentration sensor and / or an air flow rate sensor are provided in the area of ​​the base near the first filter device; a winding temperature sensor is provided in the area of ​​the base in close contact with the generator windings.

[0012] In some embodiments of the present invention, the cooling fan has a frequency converter module, and in dust removal mode, the control unit controls the frequency converter module of the cooling fan to output periodic pulses.

[0013] This invention also provides a control method for a wind turbine generator, comprising:

[0014] Determine whether the first filter is blocked based on the generator set's operating status and the airflow near the first filter.

[0015] If the first filter is clogged, the dust removal mode is restarted after the generator set stops. The dust removal mode includes controlling the generator set transmission chain and the cooling fan to reverse so that external air enters the machine base through the air inlet and outlet of the cooling shell and is discharged along the first filter of the machine base.

[0016] In some embodiments of the present invention, determining whether the first filter device is clogged based on the generator set operating status and the airflow near the first filter device includes:

[0017] If the difference between the real-time power and the full power of the generator set is less than or equal to the first threshold, it is determined whether the temperature rise of the generator winding exceeds the second threshold. If the temperature rise of the generator winding exceeds the second threshold, it is determined that the first filter device is blocked.

[0018] If the difference between the unit's real-time power and full power is greater than the first threshold, the dust concentration and air velocity in the area where the first filter is located are determined. If the dust concentration exceeds the third threshold and the air velocity is lower than the fourth threshold, the first filter is determined to be blocked.

[0019] In some embodiments of the present invention, controlling the reverse rotation of the generator set drive train and the cooling fan in dust removal mode includes:

[0020] The control unit's pitch system is set to open the pitch at a negative angle, and the generator is controlled to operate near synchronous speed;

[0021] The variable frequency module controlling the cooling fan cycles periodically n times in a pulse mode. The pulse mode includes: increasing the power frequency from a first frequency f1 to a second frequency f2 at a first speed v1 and maintaining it for a first duration t1; decreasing the power frequency from the second frequency f2 to the first frequency f1 at a second speed v2 and maintaining it for a second duration t2; wherein v2 < v1, t1 > t2.

[0022] The technical solution of the present invention has the following technical effects compared with the prior art:

[0023] The dust removal system for wind turbines provided by this invention can effectively remove dust adhering to the outside of the first filter device by controlling the cooling fan to reverse and change the airflow direction, thereby maintaining the permeability of the filter device, extending the service life of the filter device, and reducing manual maintenance costs and maintenance frequency.

[0024] The wind turbine control method provided by this invention comprehensively judges the blockage of the first filter device by using multiple parameters such as the generator set operating status and the air conditions near the first filter device, and automatically starts the dust removal mode to achieve intelligent control and improve the stability and reliability of the wind turbine operation. Attached Figure Description

[0025] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, which will help to understand the purpose and advantages of the present invention, wherein:

[0026] Figure 1 This is a perspective view of a specific embodiment of the dust removal and filtration system for a wind turbine generator according to the present invention;

[0027] Figure 2 This is a schematic diagram of a specific embodiment of the dust removal and filtration system for a wind turbine generator according to the present invention;

[0028] Figure 3 This is a system configuration diagram of a specific embodiment of the dust removal and filtration system for a wind turbine generator according to the present invention;

[0029] Figure 4 This is a control flowchart of a specific embodiment of the wind turbine generator of the present invention;

[0030] Figure 5 This is a flowchart of the wind turbine filter clogging judgment method of the present invention. Detailed Implementation

[0031] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0035] like Figure 1 , Figure 2 The image shows a specific embodiment of the filtration and dust removal system for a wind turbine provided by the present invention. The system is used to filter and cool the wind turbine when it is working, and to remove dust from the filter structure (i.e., the first filter device 13 in the following text) after it is blocked and the wind turbine is shut down.

[0036] Specifically, the filtration and dust removal system mainly consists of a base 10, a cooling assembly 20, and a control unit. The wind turbine is a doubly-fed induction generator, and its base 10 is roughly rectangular in shape with a hollow interior. The generator windings include a stator winding 11 and a rotor winding 12, with the rotor winding 12 mounted on the rotor shaft 17. Two sets of first filter devices 13 are installed on the front and rear sides of the base 10, respectively. These first filter devices 13 use high-efficiency fiber filter media, which can effectively intercept larger particles of dust, gravel, and other impurities in the air, providing a preliminary protective barrier for the generator windings.

[0037] The cooling assembly 20 includes a cooling housing 21, a cooling fan 22, and a second filter device 23. The cooling housing 21 is mounted on the base 10, and the cooling fan 22 and the second filter device 23 are mounted on the cooling housing 21. The cooling housing 21 has an air inlet and outlet 211 on the side away from the base 10 for air intake and exhaust. The cooling fan 22 is a reversible axial flow fan, which can achieve bidirectional operation.

[0038] The control unit is the core control component of the entire system. It can receive and process detection signals from various sensors in real time, thereby controlling the generator set to switch between cooling mode and dust removal mode.

[0039] In cooling mode, the control unit controls the cooling fan 22 to rotate forward. The external air is first filtered by the first filter device 13 on the front and rear sides of the base 10 to remove larger particulate impurities before entering the interior of the base 10 to cool the generator windings (stator winding 11 and rotor winding 12). Then it is discharged through the air inlet and outlet 211 of the cooling housing 21.

[0040] In dust removal mode, the control unit controls the cooling fan 22 to reverse, and the outside air enters the base 10 through the air inlet and outlet 211 of the cooling housing 21, and then is discharged along the first filter device 13 of the base 10. During this process, the airflow flows in reverse, washing away the dust attached to the first filter device 13, thereby achieving self-cleaning of the filter device.

[0041] Specifically, in one optional embodiment, the cooling fan 22 has a frequency converter module capable of high-precision frequency adjustment. In dust removal mode, the control unit controls the frequency converter module of the cooling fan 22 to periodically output pulses, generating periodically changing airflow to enhance the scouring force on the dust on the first filter device 13 and improve the dust removal effect. Simultaneously, this frequency converter control method can also reduce the fan's energy consumption, achieving energy-saving operation.

[0042] Specifically, the wind turbine is used in a wind turbine generator set with a pitch control system. In dust removal mode, the control unit controls the pitch control system to open the pitch at a negative angle, causing the transmission chain of the wind turbine generator set to reverse. The cooling assembly 20 also includes two sets of coaxial fans 24 connected to the rotor shaft 17. The two sets of coaxial fans 24 are spaced apart on the left and right sides of the rotor winding 12 and rotate synchronously with it. In cooling mode, the two sets of coaxial fans 24 generate airflow towards the rotor winding 12, enhancing air convection inside the frame 10 and further improving the cooling effect. When the rotor shaft 17 rotates at high speed, the coaxial fans 24 also rotate at high speed, quickly removing the heat generated by the generator windings and ensuring stable performance of the generator even under high load conditions. In dust removal mode, the two sets of coaxial fans 24 generate reverse airflow away from the rotor winding 12, forming turbulent airflow with the airflow generated by the cooling fan 22, which is blown out along the first filter device 13 to remove dust.

[0043] Specifically, the second filter device 23 is an electrically operated louvered filter device. The electrically operated louver consists of multiple baffles, each of which is connected to the frame via a rotating shaft. A micro motor is mounted on the rotating shaft, and the opening and closing of the louver is achieved by controlling the rotation angle of the micro motor. In cooling mode, the second filter device 23 is controlled to be in a state where the air inlet and outlet 211 are fully open. At this time, air can pass through the air inlet and outlet 211 without obstruction, ensuring maximum airflow and improving cooling efficiency. In dust removal mode, the second filter device 23 is controlled to be in a state where the air inlet and outlet 211 are partially blocked. By adjusting the opening and closing angle of the louver, a certain resistance is formed at the air inlet and outlet 211, increasing the airflow velocity and enhancing the dust removal effect on the first filter device 13. At the same time, it can also prevent dust from flowing into the base 10 along the cooling housing 21, thus playing a filtering role.

[0044] Specifically, the cooling housing 21 is mounted on the upper side of the base 10. A circular through-hole is formed on the upper surface of the base 10. The cooling housing 21 includes a mounting body 212 covering the upper side of the circular through-hole and an air guide duct 213 connected to the mounting body 212 and extending in the same direction as the rotor shaft 17. The cooling fan 22 and the second filter device 23 are mounted inside the air guide duct 213. More specifically, the second filter device 23 is located between the air inlet / outlet 211 of the cooling housing 21 and the cooling fan 22. The mounting body 212 is generally cylindrical, with its centerline perpendicular to the upper surface of the base 10. The air guide duct 213 is also cylindrical, with its side surface transitioning to the cylindrical air guide duct 213 via a square transition structure. The air guide duct 213 extends away from the generator windings, effectively guiding and concentrating airflow to ensure the cooling fan 22 can uniformly draw and discharge air, improving air circulation efficiency. Simultaneously, the air guide duct 213 also provides some protection for the cooling fan 22 and the second filter device 23, preventing external debris from entering and affecting the normal operation of the equipment.

[0045] Specifically, a dust concentration sensor and an air velocity sensor are installed in the area near the first filter device 13 within the base 10. The dust concentration sensor uses the laser scattering principle to accurately detect the dust concentration in the air; the air velocity sensor uses a thermal anemometer to monitor the airflow speed in real time. A winding temperature sensor, using a thermocouple temperature sensor, is installed near the generator windings to quickly and accurately measure the winding temperature. The control unit controls the cooling fan 22 to switch between cooling mode and dust removal mode based on the generator power, generator winding temperature rise, and detection signals from the winding temperature sensor, dust concentration sensor, and air velocity sensor. By combining the engine operating parameters with the air conditions near the first filter device 13 to determine whether it is blocked, false positives and false negatives can be avoided, ensuring the stable operation of the wind turbine. For details of the determination method, please refer to the following description of the control method.

[0046] Reference Figure 4 , Figure 5 As shown, the present invention also provides a specific embodiment of a control method for a wind turbine generator having the above-mentioned dust removal filtration system, the control method comprising:

[0047] S1. Determine whether the first filter device 13 is blocked based on the generator set's operating status and the air conditions near the first filter device 13.

[0048] Specifically, refer to Figure 5As shown, firstly, it is determined whether the real-time power of the generator set is close to the full-power state. The full-power state refers to the maximum output power that the generator set can achieve under rated operating conditions. If the real-time power T of the generator set is close to the full-power T... max The difference between them is less than or equal to the first threshold t (i.e., T). max When -T≤t), that is, the generator set is operating close to full power, the first filter device 13 may be blocked. Continue to judge whether the generator winding temperature rise exceeds the second threshold. The generator winding temperature rise is obtained based on the detection values ​​of the winding temperature sensor and the ambient temperature sensor. Generator winding temperature rise = (generator winding temperature value - ambient temperature value). If the generator winding temperature rise exceeds the second threshold, for example, if the generator winding temperature rise exceeds the warning limit of 95K, then the first filter device 13 is judged to be blocked; otherwise, the first filter device 13 is judged not to be blocked.

[0049] If the difference between the unit's real-time power and full power is greater than the first threshold (T) max -T>t), meaning the real-time power of the generator set is in a normal operating state where it is much lower than full power. At this time, the air conditions in the area where the first filter device 13 is located are judged based on the detection signals of the dust concentration sensor and the air flow rate sensor near the first filter device 13. If the dust concentration exceeds the third threshold (for example, the third threshold is 100mg / m³), the air quality will be assessed. 3 If the air velocity is below the fourth threshold (for example, the fourth threshold is 5 m / s), the first filter device 13 is determined to be blocked; otherwise, the first filter device 13 is determined to be unblocked, and the generator set remains in normal working condition.

[0050] By comprehensively judging multiple parameters, such as the generator set's operating status (including real-time power output and generator winding temperature rise) and the air conditions near the first filter device 13 (dust concentration and air velocity), it is possible to accurately determine whether the first filter device 13 is clogged. Compared with single-parameter judgment, this multi-parameter judgment method has higher accuracy and reliability, avoids misjudgment and omission, and ensures the stable operation of the wind turbine.

[0051] S2. If it is determined from step S1 above that the first filter device 13 is not blocked, while maintaining the generator set in normal grid-connected operation, control the filtration and dust removal system to operate in cooling mode; specifically, control the cooling fan 22 to rotate forward, and control the louvers of the second filter device 23 to be fully open, so that external air enters the machine base 10 through the first filter device 13, and the air flow is accelerated by the coaxial fan 24 set on the rotor shaft 17. The cooling gas flows through the stator winding 11 and the rotor winding 12 in sequence, and finally is discharged along the air inlet and outlet 211 of the cooling shell 21, so as to quickly cool down the generator set windings.

[0052] S3. If the first filter device 13 is determined to be clogged according to step S1 above, the dust removal mode is immediately activated after the generator set stops. The dust removal mode includes controlling the generator set transmission chain and the cooling fan 22 to reverse, and controlling the louvers of the second filter device 23 to be in a semi-closed state. The specific control process is as follows: the generator set pitch system is controlled to open at a negative angle, so that the generator set transmission chain runs in the opposite direction (i.e., the direction of the transmission chain is opposite to that of the generator set in grid-connected operation), and the generator is controlled to operate near the synchronous speed, so that the generator set is in a safe state and to prevent the generator set from running away due to external turbulence; at the same time, the frequency converter module of the cooling fan 22 is controlled to cycle periodically n times in pulse mode. Air enters the base 10 through the air inlet and outlet 211 of the cooling shell 21, forming turbulent air that impacts the first filter device 13 from the inside out, increasing the air pressure blown from the inside of the first filter device 13 to the outside, and blowing off the dust on its outer surface. Through this coordinated control method, efficient dust removal operation is achieved, ensuring that the first filter device 13 is cleaned without affecting the normal operation of the generator set.

[0053] More specifically, before the pulse mode is activated, AC power with a rated voltage of 380V and phase sequence exchange (making the motor rotate in reverse) is input to the frequency converter module at a power frequency of 1Hz through the electronic phase commutator. The cooling fan 22 starts slowly and keeps rotating in reverse. Then, the frequency converter module is controlled to bring the power frequency to 40Hz at a rate of 1Hz / s. At this time, the speed of the fan driven by the frequency converter motor reaches 1200rpm, and the fan rotation speed has the basic speed for generating pulse wind.

[0054] The control inverter module activates pulse mode: The power frequency is increased from a first frequency f1 (e.g., 40Hz) to a second frequency f2 (e.g., 60Hz) at a first speed (e.g., 10Hz / s) and maintained for a first duration t1 (e.g., 5s), driving the cooling fan 22 to accelerate rapidly. Then, the power frequency is decreased from the second frequency f2 (e.g., 60Hz) to the first frequency f1 (e.g., 40Hz) at a second speed v2 (e.g., 1Hz / s) and maintained for a second duration t2 (e.g., 2s). After accelerating to high-speed mode, the cooling fan 22 is driven to slowly decelerate, increasing the reverse airflow into the base 10. This generates turbulence near the generator windings, impacting the filter surface from the inside out and blowing away the attached dust. This pulse mode cycle is repeated 20 times as one dust removal operation.

[0055] After a dust removal operation, the dust concentration sensor and air flow rate sensor near the first filter device 13 are used to determine whether the first filter device 13 is blocked. If the first filter device 13 is still blocked, the dust removal operation is repeated until the detection signals of the dust concentration sensor and air flow rate sensor meet the requirements.

[0056] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A dust removal and filtration system for a wind turbine generator, characterized in that, include: A base (10) is provided, inside which a generator winding is installed. At least one set of first filter devices (13) is provided on the base (10). A dust concentration sensor and an air flow rate sensor are provided in the area of ​​the base (10) near the first filter device (13). A winding temperature sensor is provided in the area of ​​the base (10) near the generator winding. The cooling assembly (20) includes: a cooling housing (21) mounted on a base (10) and a cooling fan (22) and a second filter device (23) mounted inside the cooling housing (21). The cooling housing (21) has an air inlet and outlet (211) on the side away from the base (10). The cooling fan (22) is a reversible axial flow fan and has a frequency converter module. The second filter device (23) is an electric louvered filter device. The control unit controls the cooling fan to switch between cooling mode and dust removal mode based on the generator set power, generator winding temperature rise, winding temperature sensor, dust concentration sensor and air flow rate sensor detection signals; it also determines whether the first filter is blocked by combining the wind turbine's operating status with the air conditions near the first filter. In cooling mode, the cooling fan (22) is controlled to rotate forward, and the outside air enters the base (10) through the first filter device (13) and is discharged along the air inlet and outlet (211) of the cooling shell (21); the second filter device (23) is controlled to be in a state where the air inlet and outlet (211) are fully open; In dust removal mode, the cooling fan (22) is reversed and the frequency converter of the cooling fan (22) outputs periodic pulses; external air enters the base (10) through the air inlet and outlet (211) of the cooling shell (21) and is discharged along the first filter device (13) of the base (10); the second filter device (23) is controlled to be in a state of at least partially blocking the air inlet and outlet (211).

2. The dust removal and filtration system for a wind turbine generator according to claim 1, characterized in that, The wind turbine is a doubly-fed induction generator. In dust removal mode, the control unit controls the wind turbine's drive chain to reverse.

3. The dust removal and filtration system for a wind turbine generator according to claim 1, characterized in that, The generator winding includes a stator winding (11) and a rotor winding (12). The rotor winding (12) is mounted on a rotor shaft (17). The cooling assembly (20) also includes at least one set of coaxial fans (24) connected to the rotor shaft (17). The coaxial fans (24) rotate synchronously with the rotor winding (12).

4. The dust removal and filtration system for a wind turbine generator according to claim 3, characterized in that, The cooling housing (21) includes an air duct (213) extending in the same direction as the rotor shaft (17), and the cooling fan (22) and the second filter device (23) are installed inside the air duct (213).

5. The control method for the dust removal system of the wind turbine generator according to any one of claims 1-4, characterized in that, include: Determine whether the first filter device (13) is blocked based on the generator set's operating status and the airflow near the first filter device (13); If the first filter device (13) is blocked, the dust removal mode is restarted after the generator set is detected to be stopped. The dust removal mode includes controlling the transmission chain of the wind turbine and the cooling fan (22) to reverse so that the outside air enters the base (10) through the air inlet and outlet (211) of the cooling shell (21) and is discharged along the first filter device (13) of the base (10).

6. The control method for the dust removal system of a wind turbine generator according to claim 5, characterized in that, Determining whether the first filter (13) is blocked based on the generator set's operating status and the airflow near the first filter (13) includes: If the difference between the real-time power and the full power of the generator set is less than or equal to the first threshold, it is determined whether the temperature rise of the generator winding exceeds the second threshold. If the temperature rise of the generator winding exceeds the second threshold, it is determined that the first filter device (13) is blocked. If the difference between the real-time power and the full power of the unit is greater than the first threshold, the dust concentration and air velocity in the area where the first filter device (13) is located are determined. If the dust concentration exceeds the third threshold and the air velocity is lower than the fourth threshold, the first filter device (13) is determined to be blocked.

7. The control method for the dust removal system of a wind turbine generator according to claim 5, characterized in that, In dust removal mode, the reverse rotation of the wind turbine's drive train and cooling fan (22) includes: The control unit's pitch system is set to open the pitch at a negative angle, and the wind turbine is controlled to operate near synchronous speed; The frequency converter module controlling the cooling fan (22) cycles periodically n times in a pulse mode. The pulse mode includes: increasing the power frequency from the first frequency f1 to the second frequency f2 at a first speed v1 and maintaining it for a first duration t1; decreasing the power frequency from the second frequency f2 to the first frequency f1 at a second speed v2 and maintaining it for a second duration t2; wherein v2 < v1, t1 > t2.

Images