System and method for detecting rotating speed of direct-driven wind driven generator

Abstract

The invention relates to the technical field of wind power generation, and discloses a rotating speed detection system and method for a direct-driven wind driven generator, the system is applied to the direct-driven wind driven generator, the direct-driven wind driven generator comprises a generator rotor, and the system comprises a visible light source emitting device, an image receiving device and a main control device. The visible light source emitting device is arranged on the inner wall of the generator rotor; the image receiving device obtains image information and sends the image information to the main control device, and the positions of the visible light at different moments are recorded in the image information; the main control device determines the pixel displacement of the light source emitting device in a preset time period according to the positions of the visible light at different moments in the image information; and determining the rotating speed of the generator rotor in the preset time period according to the pixel displacement. As the visible light source emitting device is not interfered by the generator when emitting visible light, the measured rotating speed is more accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power generation, and in particular to a rotation speed detection system and method for a direct-drive wind power generator. Background Art

[0002] A direct-drive wind turbine is a generator driven directly by wind, also known as a gearless wind engine. This type of generator uses a multi-pole motor directly connected to the impeller for driving, eliminating the traditional component of the gearbox. Since the gearbox is a component that is prone to overload and premature damage in megawatt-class wind turbines, direct-drive wind engines without gearboxes have many advantages, such as high efficiency at low wind speeds, low noise, long life, reduced unit size, and reduced operation and maintenance costs.

[0003] In order to measure the rotation speed of a direct-drive wind turbine, a sensor is usually installed on the direct-drive wind turbine to detect its rotation speed. However, the sensor is easily affected by electromagnetic interference from the generator, resulting in inaccurate detection. Summary of the invention

[0004] In view of this, the present invention provides a direct-drive wind generator speed detection system and method to solve the problem that the direct-drive wind generator speed is easily affected by the electromagnetic interference of the generator when the sensor is used to detect the speed of the direct-drive wind generator.

[0005] In a first aspect, the present invention provides a direct-drive wind generator speed detection system, which is applied to a direct-drive wind generator. The direct-drive wind generator includes a generator rotor, which includes a first side and a second side opposite to the first side. The diameter of the generator rotor gradually increases from the first side to the second side. The system includes a visible light source emitting device, an image receiving device and a main control device. The visible light source emitting device is arranged on the inner wall of the first side of the generator rotor. When the generator rotor rotates, the visible light source emitting device emits visible light in the direction of the image receiving device. The image receiving device acquires image information and sends the image information to the main control device. The image information records the position of the visible light at different times. The main control device determines the pixel displacement of the visible light source emitting device within a time period of a preset time length according to the position of the visible light at different times in the image information. The speed of the generator rotor within the time period of the preset time length is determined according to the pixel displacement.

[0006] There is a visible light source emitting device. When the generator rotor rotates, the visible light source emitting device rotates therewith and emits visible light at the same time. The image information collected by the image receiving device can record the position of the visible light at different times, so that the pixel displacement of the visible light source emitting device within a preset time period can be determined according to the position of the visible light at different times, and the rotation speed of the generator rotor within the preset time period can be further determined. Since the visible light source emitting device will not be affected by the electromagnetic interference of the generator when emitting visible light, the measured rotation speed is more accurate.

[0007] In an optional embodiment, the direct-drive wind turbine also includes a generator slip ring, which is arranged at the axial position of the generator rotor. The system also includes a power cord of a visible light source emitting device, one end of the power cord of the visible light source emitting device is connected to the generator slip ring, and the other end is connected to the visible light source emitting device, and the generator slip ring is used to power the visible light source emitting device.

[0008] In an optional embodiment, the system includes multiple visible light source emitting devices, and the visible light emitted by each visible light source emitting device presents different characteristics in the image information collected by the image receiving device; the main control device determines the pixel displacement of each visible light source emitting device within a time period of preset duration based on the visible light with different characteristics in the image information; calculates the rotation speed of each visible light source emitting device according to the corresponding pixel displacement of each visible light source emitting device; and determines the rotation speed of the generator rotor within a time period of preset duration based on the rotation speed of each visible light source emitting device.

[0009] In the embodiment of the present invention, since different visible light source emitting devices produce different characteristics of visible light in the image information, the pixel displacement of each visible light source emitting device within a preset time period can be determined according to the aperture presented in the image information by the visible light of different characteristics, so that the rotation speed of each visible light source emitting device can be calculated respectively. Since the visible light source emitting device may malfunction when emitting visible light and the emitted visible light may also be blocked, errors will occur if the rotation speed of the generator rotor is determined only by the pixel displacement of one visible light source emitting device. In the embodiment of the present invention, the rotation speeds of the multiple visible light source emitting devices are calculated respectively by using the visible light emitted by the multiple visible light source emitting devices, and then the rotation speeds of the multiple visible light source emitting devices are combined to obtain a more accurate rotation speed of the generator rotor.

[0010] In an optional embodiment, the system includes multiple image receiving devices, and the main control device determines the rotational speed of the generator rotor within a preset time period based on the image information sent by each image receiving device, and performs a comprehensive analysis on the rotational speed calculated based on each image information to obtain the final rotational speed of the generator rotor within the preset time period.

[0011] In the process of visible light emitted by the visible light source emitting device entering the image receiving device, the visible light may be blocked, the imaging function of the image receiving device may be damaged, and a variety of different factors may cause the image receiving device to be unable to completely collect the visible light emitted by the visible light source emitting device during the movement. Therefore, in an embodiment of the present invention, multiple image receiving devices are provided, and the image information collected by the multiple image receiving devices is combined to calculate the rotational speed of the generator rotor within a preset time period, and the final result is more reliable.

[0012] In an optional embodiment, a direct-drive wind turbine includes a slip ring bracket, which is connected to a generator slip ring. The setting direction of the slip ring bracket is perpendicular to the axis of the generator rotor. The main control device determines whether there is an area blocked by the slip ring bracket within a preset time period based on the image information. If not, the pixel displacement of the visible light source emitting device within the preset time period is determined based on the position of the visible light at different times in the image information, and the rotation speed of the generator rotor within the preset time period is determined based on the pixel displacement.

[0013] In an optional embodiment, the direct-drive wind turbine includes a nacelle platform, the nacelle platform is arranged in a direction close to the first side of the generator rotor, and the image receiving device is horizontally placed on the surface of the nacelle platform.

[0014] In a second aspect, a method for detecting the rotational speed of a direct-drive wind turbine generator is applied to a main control device in a system of the first aspect or any corresponding embodiment thereof, the method comprising: acquiring image information, the image information recording the position of visible light at different times, the visible light being emitted by a visible light source emitting device disposed on the inner wall of a generator rotor; determining a pixel displacement of the visible light source emitting device within a time period of a preset duration based on the position of the visible light at different times in the image information; and determining the rotational speed of the generator rotor within a time period of a preset duration based on the pixel displacement.

[0015] In a third aspect, the present invention provides a computer device, comprising: a memory and a processor, the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the direct-drive wind turbine speed detection method of the second aspect mentioned above by executing the computer instructions.

[0016] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the direct-drive wind turbine generator speed detection method of the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 is a schematic diagram of a direct-drive wind turbine generator speed detection system according to an embodiment of the present invention;

[0019] Figure 2 is a schematic diagram of calculating the rotation speed according to the pixel displacement of the visible light source emitting device within a preset time period in an embodiment of the present invention;

[0020] Figure 3 is a schematic diagram of a visible light source emitting device in a direct-drive wind turbine generator speed detection system according to an embodiment of the present invention;

[0021] Figure 4 is a schematic flow chart of a method for detecting the rotation speed of a direct-drive wind turbine generator according to an embodiment of the present invention;

[0022] Figure 5 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0024] In an embodiment of the present invention, a direct-drive wind turbine generator speed detection system is provided, which is applied to a direct-drive wind turbine generator, such as Figure 1 As shown, the direct-drive wind turbine includes a generator rotor 1, which includes a first side and a second side opposite to the first side. The diameter of the generator rotor 1 gradually increases from the first side to the second side. The system includes a visible light source emitting device 2, an image receiving device 7 and a main control device 8. The visible light source emitting device 2 is arranged on the inner wall of the first side of the generator rotor 1, that is, the visible light source emitting device 2 is arranged on the side of the generator rotor 1 with a smaller diameter.

[0025] When the generator rotor 1 rotates, the visible light emitting device 2 emits visible light in the direction of the image receiving device 7. Since the visible light emitting device 2 is arranged on the inner wall of the generator rotor 1, when the generator rotor 1 rotates, the visible light emitting device 2 also rotates with the generator rotor 1, so that the image receiving device 7 can collect the visible light rotating with the generator rotor 1.

[0026] In an optional embodiment, the visible light source emitting device 2 can be a laser positioning lamp. The laser positioning lamp can produce an ultra-small light spot. The light it emits is highly focused and can form a circular light spot with a smaller diameter within a certain distance. Since the rotation speed of the generator needs to be determined based on the position of the light spot at different times collected by the image receiving device 7, if the light spot of the visible light is large, the position of the visible light source emitting device 2 at different times cannot be accurately determined based on the position of the light spot, and thus the rotation speed of the generator rotor 1 cannot be accurately determined. Therefore, if a laser positioning lamp is used, a light spot with a smaller diameter can be formed, so that the calculated rotation speed is more accurate. In addition, since the visible light emitted by the laser positioning lamp has strong directionality and concentrated energy when propagating in a medium such as air, it can maintain a good penetration effect to a certain extent in environments such as smoke and dust, and can accurately determine the rotation speed of the generator rotor 1 even in complex environments.

[0027] The image receiving device 7 acquires image information and sends the image information to the main control device 8. The image information records the positions of the visible light at different times.

[0028] In the embodiment of the present invention, as the generator rotor 1 rotates, the visible light source emitting device 2 will also rotate, so that the visible light emitted by the visible light source emitting device 2 will also appear at different positions at different times.

[0029] The main control device 8 determines the pixel displacement of the light source emitting device within a preset time period according to the position of the visible light in the image information at different times; and determines the rotation speed of the generator rotor 1 within the preset time period according to the pixel displacement.

[0030] In an optional embodiment, after receiving the light source, the main control device 8 analyzes the data through image processing technology to obtain the pixel displacement of the visible light within a period of time. For example, the image information can be analyzed through the yolo algorithm, OpenCV algorithm, etc. to obtain the pixel displacement of the visible light within a period of time. For example, Figure 2 Shown is the pixel displacement of the visible light obtained by analysis over a period of time.

[0031] After obtaining the pixel displacement of visible light within a period of time, the image pixel coordinates are established by calibrating the rotation of visible light, so that the radians traveled by the generator per second can be obtained according to the pixel movement of visible light. The formula is: ω=φ / t, where φ is the radians traveled, t is the time, and the unit of ω is: radians per second (rad / s). Then, the generator speed rpm is obtained according to the radians traveled by the generator per second.

[0032] The direct-drive wind turbine speed detection system provided by the embodiment of the present invention has a visible light source emitting device 2 arranged on the inner side of the generator rotor 1. When the generator rotor 1 rotates, the visible light source emitting device 2 rotates therewith and emits visible light at the same time. The image information collected by the image receiving device 7 can record the position of the visible light at different times, so that the pixel displacement of the visible light source emitting device 2 within a time period of a preset length can be determined according to the position of the visible light at different times, and the speed of the generator rotor 1 within the time period of the preset length can be further determined. Since the visible light source emitting device 2 will not be affected by the electromagnetic interference of the generator when emitting visible light, the measured speed is more accurate.

[0033] In an alternative embodiment, if Figure 1 As shown, the direct-drive wind turbine also includes a generator slip ring 4, which is arranged at the axial position of the generator rotor 1. The system also includes a visible light source emitting device power line 3, one end of the visible light source emitting device power line 3 is connected to the generator slip ring 4, and the other end is connected to the visible light source emitting device 2, and the generator slip ring 4 is used to power the visible light source emitting device 2.

[0034] During the operation of the generator, the slip ring serves as an electrical connection interface between the rotating part (rotor) and the stationary part (external DC power supply), and can introduce external DC current into the rotor winding. Therefore, the generator slip ring 4 can provide electrical energy for the visible light source emitting device 2, and there is no need to set up an additional power supply device in the direct-drive wind turbine speed detection system.

[0035] In an alternative embodiment, if Figure 3 As shown, the system includes a plurality of visible light source emitting devices 2, and the visible light emitted by each visible light source emitting device 2 presents different characteristics in the image information collected by the image receiving device 7. The characteristics presented by the visible light in the image information may be color, position, etc., wherein the position refers to the distance between the light spot generated by the visible light and the center of a circle in the image, that is, different visible lights present different colors in the image information, and different visible lights have different distances from the center of a circle in the image information, resulting in different radii of the aperture.

[0036] The main control device 8 determines the pixel displacement of each visible light source emitting device 2 within a time period of preset duration based on the visible light with different characteristics in the image information; calculates the rotation speed of each visible light source emitting device 2 according to the corresponding pixel displacement of each visible light source emitting device 2; and determines the rotation speed of the generator rotor 1 within a time period of preset duration based on the rotation speed of each visible light source emitting device 2.

[0037] In the embodiment of the present invention, since different visible light source emitting devices 2 generate different characteristics of visible light in the image information, the pixel displacement of each visible light source emitting device 2 within a preset time period can be determined according to the aperture presented in the image information by the visible light with different characteristics, so that the rotation speed of each visible light source emitting device 2 can be calculated respectively. Since the visible light source emitting device 2 may malfunction when emitting visible light and the emitted visible light may also be blocked, if the rotation speed of the generator rotor 1 is determined by only the pixel displacement of one visible light source emitting device 2, errors will occur. In the embodiment of the present invention, the rotation speeds of the multiple visible light source emitting devices 2 are calculated respectively by using the visible light emitted by the multiple visible light source emitting devices 2, and then the rotation speeds of the multiple visible light source emitting devices 2 are combined to obtain a more accurate rotation speed of the generator rotor 1.

[0038] In an optional embodiment, when determining the rotation speed of the generator rotor 1 within a preset time period by the rotation speeds of multiple visible light source emitting devices 2, different methods can be selected according to actual needs, for example:

[0039] Method 1: If the rotational speeds of the visible light source emitting devices 2 are not exactly the same, and the number of visible light source emitting devices 2 with the same rotational speed is greater than a preset value, it is determined that there is an error in the rotational speeds of the remaining visible light source emitting devices 2, and the rotational speed of the generator rotor 1 is determined according to the rotational speeds corresponding to the visible light source emitting devices 2 with the same rotational speed, wherein the preset value can be set according to actual needs. By way of example, the preset value can be 2 / 3 of the total number of visible light source emitting devices 2.

[0040] Method 2: if the rotation speeds of the visible light source emitting devices 2 are not completely the same, the rotation speed of the generator rotor 1 is determined according to the median value of the rotation speeds corresponding to the visible light source emitting devices 2 .

[0041] In an optional embodiment, the system includes multiple image receiving devices 7, and the main control device 8 determines the rotational speed of the generator rotor 1 within a preset time period based on the image information sent by each image receiving device 7, and performs a comprehensive analysis on the rotational speed calculated based on each image information to obtain the final rotational speed of the generator rotor 1 within the preset time period.

[0042] In the process of visible light emitted by the visible light source emitting device 2 entering the image receiving device 7, the visible light may be blocked, the imaging function of the image receiving device 7 may be damaged, and a variety of different factors may cause the image receiving device 7 to be unable to completely collect the visible light emitted by the visible light source emitting device 2 during the movement. Therefore, in an embodiment of the present invention, multiple image receiving devices 7 are provided, and the image information collected by the multiple image receiving devices 7 is combined to calculate the rotational speed of the generator rotor 1 within a preset time period, and the final result is more reliable.

[0043] In an alternative embodiment, if Figure 1 As shown, the direct-drive wind turbine generator includes a nacelle inner platform 6 , which is arranged in a direction close to the first side of the generator rotor 1 , and an image receiving device 7 is horizontally placed on the surface of the nacelle inner platform 6 .

[0044] In an alternative embodiment, if Figure 3 As shown, the direct-drive wind turbine includes a slip ring bracket 5, which is connected to the generator slip ring 4. The setting direction of the slip ring bracket 5 is perpendicular to the axis of the generator rotor 1. Since the setting direction of the slip ring bracket 5 is perpendicular to the axis of the generator rotor 1, each visible light source emitting device 2 rotates in a plane perpendicular to the axis of the generator rotor 1 as the generator rotor 1 rotates. Therefore, the slip ring bracket 5 will block the visible light emitted by the visible light source emitting device 2. At this time, in order to avoid errors in the calculation of the rotation speed of the generator rotor 1, in an embodiment of the present invention, the main control device 8 determines whether there is an area blocked by the slip ring bracket 5 within a time period of a preset time length according to the image information. If not, the pixel displacement of the visible light source emitting device 2 within the time period of the preset time length is determined according to the position of the visible light at different times in the image information, and the rotation speed of the generator rotor 1 within the time period of the preset time length is determined according to the pixel displacement.

[0045] In this embodiment, a method for detecting the rotation speed of a direct-drive wind turbine generator is also provided, which can be used in the above-mentioned main control device 8. Figure 4 1 is a flow chart of a method for detecting the speed of a direct-drive wind turbine according to an embodiment of the present invention. It should be noted that the steps shown in the flow chart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flow chart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0046] Step S401, acquiring image information, the image information records the position of visible light at different times, the visible light is emitted by the visible light source emitting device 2 arranged on the inner wall of the generator rotor 1, and the details are described in the above embodiment, which will not be repeated here.

[0047] Step S402, determining the pixel displacement of the light source emitting device within a preset time period according to the position of the visible light in the image information at different times, for details, see the description in the above embodiment, which will not be repeated here.

[0048] Step S403, determining the rotation speed of the generator rotor 1 within a preset time period according to the pixel displacement, for details, refer to the description in the above embodiment, which will not be repeated here.

[0049] See also Figure 5 , Figure 5 is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Figure 5 As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 5 A processor 10 is taken as an example.

[0050] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0051] The memory 20 stores instructions executable by at least one processor 10, so that at least one processor 10 executes the method shown in the above embodiment.

[0052] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0053] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0054] The computer device also includes an input device 30 and an output device 40. The processor 10, the memory 20, the input device 30 and the output device 40 may be connected via a bus or other means. Figure 5 The example of connecting through bus is taken in the following.

[0055] The input device 30 can receive input digital or character information, and generate key signal input related to the user settings and function control of the computer device, such as a touch screen, a keypad, a mouse, a track pad, a touch pad, an indicator bar, one or more mouse buttons, a trackball, a joystick, etc. The output device 40 may include a display device, an auxiliary lighting device (e.g., an LED) and a tactile feedback device (e.g., a vibration motor), etc. The above-mentioned display device includes but is not limited to a liquid crystal display, a light emitting diode, a display and a plasma display. In some optional embodiments, the display device can be a touch screen.

[0056] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0057] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A direct-drive wind turbine generator speed detection system, characterized in that: The invention is applied to a direct-drive wind turbine generator, wherein the direct-drive wind turbine generator comprises a generator rotor, wherein the generator rotor comprises a first side and a second side opposite to the first side, wherein the diameter of the generator rotor gradually increases from the first side to the second side, and wherein the system comprises a visible light source emitting device, an image receiving device and a main control device, wherein the visible light source emitting device is arranged on the inner wall of the first side of the generator rotor, When the generator rotor rotates, the visible light source emitting device emits visible light in the direction where the image receiving device is located; The image receiving device acquires image information and sends the image information to the main control device, wherein the image information records the position of the visible light at different times; The main control device determines the pixel displacement of the visible light source emitting device within a time period of a preset length according to the position of the visible light in the image information at different times; The rotation speed of the generator rotor within a time period of the preset duration is determined according to the pixel displacement.

2. The system according to claim 1, characterized in that The direct-drive wind turbine generator further comprises a generator slip ring, which is arranged at the axis position of the generator rotor. The system further comprises a power line of a visible light source emitting device. One end of the power line of the visible light source emitting device is connected to the generator slip ring, and the other end is connected to the visible light source emitting device, and the generator slip ring is used to power the visible light source emitting device.

3. The system according to claim 1, characterized in that The system includes a plurality of visible light source emitting devices, and the visible light emitted by each visible light source emitting device has different features presented in the image information collected by the image receiving device; The main control device determines the pixel displacement of each of the visible light source emitting devices within a preset time period according to the visible light with different characteristics in the image information; The rotation speed of each visible light source emitting device is calculated according to the pixel displacement corresponding to each visible light source emitting device; and the rotation speed of the generator rotor within the preset time period is determined according to the rotation speed of each visible light source emitting device.

4. The system according to claim 1 or 3, characterized in that: The system comprises a plurality of image receiving devices. The main control device determines the rotational speed of the generator rotor within the preset time period based on the image information sent by each image receiving device, and performs a comprehensive analysis on the rotational speed calculated based on each image information to obtain the final rotational speed of the generator rotor within the preset time period.

5. The system according to claim 2, characterized in that The direct-drive wind turbine generator comprises a slip ring bracket, the slip ring bracket is connected to the generator slip ring, and the setting direction of the slip ring bracket is perpendicular to the axis of the generator rotor. The main control device determines, based on the image information, whether there is an area blocked by the slip ring bracket within a time period of a preset duration for the visible light; if not, the main control device determines the pixel displacement of the visible light source emitting device within the time period of a preset duration based on the position of the visible light at different times in the image information, and determines the rotation speed of the generator rotor within the time period of the preset duration based on the pixel displacement.

6. The system according to claim 1, characterized in that The direct-drive wind turbine generator comprises a platform in the nacelle, The platform in the nacelle is arranged in a direction close to the first side of the generator rotor, and the image receiving device is horizontally placed on the surface of the platform in the nacelle.

7. A method for detecting the rotation speed of a direct-drive wind turbine generator, characterized in that: A main control device applied to a system according to any one of claims 1 to 6, the method comprising: Acquiring image information, wherein the image information records positions of visible light at different times, wherein the visible light is emitted by a visible light source emitting device disposed on an inner wall of a generator rotor; Determining the pixel displacement of the visible light source emitting device within a time period of a preset length according to the position of the visible light in the image information at different times; The rotation speed of the generator rotor within a time period of the preset duration is determined according to the pixel displacement.

8. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method of claim 7 by executing the computer instructions.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the method of claim 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the method of claim 7.

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