A mechanical-hydraulic hybrid transmission dual-rotor wind turbine and its control method

Abstract

This invention provides a mechanical-hydraulic hybrid transmission dual-rotor wind turbine and its control method. The large and small rotors are respectively connected to the input shaft of a differential. The output shaft of the differential is connected to a first speed increaser, and the output shaft of the first speed increaser is connected to a small-power generator. A yaw system for the wind turbine is installed between the first speed increaser and the tower. The transmission method adopts a mechanical-hydraulic hybrid transmission. The hydraulic transmission system includes a hydraulic pump, a check valve, a safety valve, an oil tank, and a hydraulic motor. The output shaft of the hydraulic motor is connected to a second speed increaser, and the output shaft of the second speed increaser is connected to a large-power generator. This invention solves the problems of long transmission chains, high center of gravity, difficult maintenance, and the inability of offshore floating dual-rotor wind turbines to withstand storms.

Description

Technical Field

[0001] This invention relates to the field of wind power generation, specifically to a mechanical-hydraulic hybrid transmission type dual-rotor wind turbine and its control method. Background Technology

[0002] 1. Wind is an inexhaustible resource that does not cause harm or pollution to nature. It is a new energy source that is very suitable for local use. Wind turbines convert wind energy into mechanical energy and then into electrical energy.

[0003] 2. In recent years, the newly installed capacity of wind turbines worldwide has continued to climb. With the continuous development of wind power generation technology, existing dual-rotor wind turbines have problems such as long transmission chains, high gearbox failure rates, large nacelle weight, poor stability (high center of gravity), and difficult maintenance. Offshore floating dual-rotor wind turbines are difficult to withstand storms. The maintenance costs, operational reliability, and service life of wind power equipment are receiving increasing attention.

[0004] 3. For single-rotor wind turbines, increasing blade size has become the main way to improve energy capture efficiency. The wind energy capture efficiency of traditional single-rotor wind turbines has approached its theoretical limit, and further improvement is extremely difficult and costly. Compared with traditional single-rotor wind turbines, dual-rotor wind turbines can reduce unit cost by 10%, increase wind energy utilization by 15%, reduce turbine rotor size by nearly half, and increase wind energy capture power per unit swept area at rated power to about twice the original. In the same area of ​​wind farm, the use of dual-rotor wind turbines can significantly increase the number of turbines and power generation by more than 50%, saving a lot of land resources. Dual-rotor wind turbines have lower requirements for materials, manufacturing, transportation, installation, and maintenance, and the cost is also reduced accordingly, making their application prospects extremely broad. Summary of the Invention

[0005] The purpose of this invention is to improve wind energy capture efficiency, increase power generation, and solve the problems of long transmission chains, high center of gravity, difficult maintenance, and the inability of offshore floating dual-rotor wind turbines to withstand storms. This invention provides a mechanical-hydraulic hybrid transmission dual-rotor wind turbine and its control method.

[0006] To achieve the above-mentioned technical features, the present invention aims to provide a mechanical-hydraulic hybrid transmission dual-rotor wind turbine, comprising a large rotor, a small rotor, a tower, a nacelle, a wind turbine yaw system, a differential, a first speed increaser, a small-power generator, a hydraulic pump, a check valve, a safety valve, an oil tank, a hydraulic motor, a second speed increaser, and a high-power generator. The large rotor and the small rotor are respectively connected to the input shaft of the differential, the output shaft of the differential is connected to the first speed increaser, the output shaft of the first speed increaser is connected to the small-power generator, and the wind turbine yaw system is installed between the first speed increaser and the tower. The transmission method adopts a mechanical-hydraulic hybrid transmission. The hydraulic transmission system includes a hydraulic pump, a check valve, a safety valve, an oil tank, and a hydraulic motor. The output shaft of the hydraulic motor is connected to the second speed increaser, and the output shaft of the second speed increaser is connected to the high-power generator.

[0007] During the mechanical-hydraulic hybrid transmission process, when the wind speed is lower than the set wind speed standard, the differential output shaft drives the first speed increaser. After the speed increaser increases the speed, the small power generator converts the mechanical energy into electrical energy.

[0008] When the wind speed is higher than the set wind speed standard, some mechanical energy is converted into electrical energy by a small-power generator. The hydraulic transmission system converts the other part of the mechanical energy into hydraulic energy and transmits it to the second speed increaser at the bottom of the tower. After the speed increaser increases the rotation speed, the mechanical energy is converted into electrical energy by a high-power generator.

[0009] The first speed increaser includes a first sun gear, which meshes with a first planet gear for transmission. The first planet gear meshes with a first ring gear inside the gearbox for transmission. The first planet gear is mounted on a first planet carrier. A first bevel gear of the differential is fitted on the main shaft of the first planet carrier. A second bevel gear is mounted on the other end of the axle of the first sun gear.

[0010] The growth rate ratio of the first speed increaser is between 1 / 40 and 1 / 130, the power of the small-power generator is between 5MW and 10MW, the growth rate ratio of the second speed increaser is between 1 / 60 and 1 / 150, and the power of the large-power generator is between 6MW and 15MW.

[0011] The large and small impellers, differential and first speed increaser are installed on the yaw system of the wind turbine, which is fixed on the tower, which is installed on a floating platform on land or at sea.

[0012] The second speed increaser includes a second sun gear, which meshes with a second planet gear for transmission. The second planet gear meshes with a second ring gear inside the gearbox for transmission. The second planet gear is mounted on a second planet carrier.

[0013] A control method for a mechanical-hydraulic hybrid transmission dual-rotor wind turbine includes the following steps:

[0014] In a wind turbine, the large and small impellers are connected to the input of a differential, which combines the power flowing into the two impellers and outputs it through the output shaft of the differential. The output of the differential is connected to the first speed increaser. When the wind blows the large and small impellers to rotate, the wind energy is converted into mechanical energy. The output of the first speed increaser is connected to a small power generator. After the speed is increased by the first speed increaser, the small power generator converts the mechanical energy into electrical energy.

[0015] Wind turbines need to extract wind energy to the maximum extent, but the wind direction may change at any time. The nacelle is installed on the yaw system of the wind turbine. When the wind speed and direction change, the speed sensor on the top of the nacelle sends the wind speed and direction signals to the electronic controller. The electronic controller sends a signal to the yaw system of the wind turbine to make the yaw motor rotate the nacelle so that the large rotor and the small rotor are always facing the wind direction.

[0016] The large and small impellers are connected to the differential input shaft. The wind drives the large and small impellers to rotate, which in turn drives the differential input shaft. A stator and rotor are installed inside the small-power generator. The differential output shaft drives the generator rotor to rotate in the stator, cutting magnetic field lines and generating an induced electromotive force, thus converting wind energy into mechanical energy. When the wind speed is lower than the set wind speed standard, the differential output shaft drives the first speed increaser. After the speed increaser increases the speed, the small-power generator converts the mechanical energy into electrical energy. When the wind speed is higher than the set wind speed standard, some of the mechanical energy is converted into electrical energy by the small-power generator. The hydraulic transmission system converts the remaining mechanical energy into hydraulic energy and transmits it to the second speed increaser at the bottom of the tower. The second speed increaser converts the hydraulic energy into mechanical energy and increases the speed, then drives the large-power generator to convert the mechanical energy into electrical energy.

[0017] The hydraulic pump provides pressurized oil to the system, converting mechanical energy into hydraulic energy; the control and regulating device, the check valve, controls the flow direction of the fluid; the safety valve is used to control the pressure of the fluid in the hydraulic transmission system, ensuring the stability and safety of the hydraulic transmission system; the oil tank is used to store the fluid in the hydraulic transmission system; and the actuator, the hydraulic motor, converts hydraulic energy into mechanical energy for output.

[0018] The present invention has the following beneficial effects:

[0019] 1. This invention employs a mechanical-hydraulic hybrid transmission method, placing some components of the dual-blade wind turbine at the bottom of the tower. Utilizing the advantages of lightweight and compact hydraulic transmission components, the transmission chain length of the dual-blade wind turbine is shortened, the nacelle weight is reduced, and the overall center of gravity of the dual-blade wind turbine is lowered. Placing some components of the dual-blade wind turbine at the bottom of the tower facilitates maintenance and improves the storm resistance of the offshore floating dual-blade wind turbine. The mechanical-hydraulic hybrid transmission combines the high efficiency of mechanical transmission with the advantages of lightweight, compact, and fast-response hydraulic transmission components, effectively overcoming the shortcomings of high failure rates, short transmission distances, and low transmission efficiency in mechanical transmissions, thus solving the deficiencies of existing technologies.

[0020] 2. In this invention, the two input shafts of the differential connect the large impeller and the small impeller, which solves the problem of kinetic energy loss caused by the different rotation speeds of the impellers when the dual-impeller wind turbine is operating.

[0021] 3. In this invention, two generators with different power ratings adapt to different wind conditions. When the wind speed is lower than the set wind speed standard, the smaller generator converts mechanical energy into electrical energy. When the wind speed is higher than the set wind speed standard, both the smaller and larger generators convert mechanical energy into electrical energy simultaneously, thereby improving the utilization rate of wind energy. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0024] Figure 2 This is a schematic diagram of the internal structure of the present invention.

[0025] Figure 3 This is a partial enlarged view of point A of the first speed increaser in this invention.

[0026] Figure 4 This is a partial enlarged view of the second speed increaser B in this invention.

[0027] In the diagram: 1a-Large impeller, 1b-Small impeller, 2-Tower, 3-Nacelle, 4-Wind turbine yaw system, 5-Differential gear, 5a-First bevel gear, 6-First speed increaser, 6a-First planetary gear, 6b-First sun gear, 6c-First planetary carrier, 6d-First ring gear, 6e-Second bevel gear, 7-Small power generator, 8-Hydraulic pump, 9-Check valve, 10-Safety valve, 11-Oil tank, 12-Hydraulic motor, 13-Second speed increaser, 13a-Second planetary gear, 13b-Second sun gear, 13c-Second planetary carrier, 13d-Second ring gear, 14-High power generator. Detailed Implementation

[0028] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0029] Example 1:

[0030] See Figure 1-4 A mechanical-hydraulic hybrid transmission dual-rotor wind turbine includes a large rotor 1a, a small rotor 1b, a tower 2, a nacelle 3, a wind turbine yaw system 4, a differential 5, a first speed increaser 6, a small-power generator 7, a hydraulic pump 8, a check valve 9, a safety valve 10, an oil tank 11, a hydraulic motor 12, a second speed increaser 13, and a high-power generator 14. The large rotor 1a and the small rotor 1b are respectively connected to the input shaft of the differential 5. The output shaft of the differential 5 is connected to the first speed increaser 6. The output shaft of the first speed increaser 6 is connected to the small-power generator 7. The wind turbine yaw system 4 is installed between the first speed increaser 6 and the tower 2. The transmission method adopts a mechanical-hydraulic hybrid transmission. The hydraulic transmission system includes a hydraulic pump 8, a check valve 9, a safety valve 10, an oil tank 11, and a hydraulic motor 12. The output shaft of the hydraulic motor 12 is connected to the second speed increaser 13. The output shaft of the second speed increaser 13 is connected to the high-power generator 14. By employing the aforementioned dual-rotor wind turbine, the dual-rotor wind turbine components are placed at the base of the tower. Utilizing the advantages of lightweight and compact hydraulic transmission components, the transmission chain length of the dual-rotor wind turbine is shortened, the nacelle weight is reduced, and the overall center of gravity of the dual-rotor wind turbine is lowered. Placing some components at the base of the tower facilitates maintenance and improves the storm resistance of the offshore floating dual-rotor wind turbine. The use of a mechanical-hydraulic hybrid transmission combines the high efficiency of mechanical transmission with the advantages of lightweight, compact, and fast-response hydraulic transmission components.

[0031] Furthermore, such as Figure 2 As shown, differential 5 is widely used in automobiles. A differential is a mechanism that allows the left and right drive wheels to rotate at different speeds. When a car turns, the turning radii of the inner and outer wheels are different; the turning radius of the outer wheel is larger than that of the inner wheel. This requires the outer wheel to rotate at a higher speed than the inner wheel. The function of the differential is to meet this requirement of different wheel speeds during a turn. Applying a differential to a wind turbine, the large impeller 1a and the small impeller 1b are connected to the input terminals of differential 5, merging the power flowing in from both impellers and outputting it through the output shaft of differential 5. The output terminal of differential 5 is connected to the first speed increaser 6. When the wind blows, causing the large impeller 1a and the small impeller 1b to rotate, wind energy is converted into mechanical energy. The output terminal of the first speed increaser 6 is connected to a small-power generator 7. After the speed increase is achieved by the first speed increaser 6, the small-power generator 7 converts the mechanical energy into electrical energy.

[0032] Furthermore, during the aforementioned mechanical-hydraulic hybrid transmission process, when the wind speed is lower than the set wind speed standard, the output shaft of the differential 5 drives the first speed increaser 6. After the speed increaser 6 increases the rotational speed, the mechanical energy is converted into electrical energy by the small-power generator 7. Through the aforementioned differential 5, different types of wind power can be fully utilized, thereby improving the utilization rate of wind energy.

[0033] Furthermore, when the wind speed exceeds the set wind speed standard, some mechanical energy is converted into electrical energy by the small-power generator 7. The hydraulic transmission system converts the remaining mechanical energy into hydraulic energy and transmits it to the second speed increaser 13 at the bottom of the tower 2. After the second speed increaser 13 increases the rotational speed, the mechanical energy is converted into electrical energy by the high-power generator 14. The above structure enables operation at high wind speeds.

[0034] Furthermore, the first speed increaser 6 includes a first sun gear 6b, which meshes with a first planetary gear 6a. The first planetary gear 6a meshes with a first ring gear 6d inside the housing. The first planetary gear 6a is mounted on a first planetary carrier 6c. A first bevel gear 5a of the differential 5 is mounted on the main shaft of the first planetary carrier 6c. A second bevel gear 6e is mounted on the other end of the axle of the first sun gear 6b. The first speed increaser 6 thus achieves a speed increase effect, thereby driving the small-power generator 7 to generate electricity.

[0035] Furthermore, the speed increase ratio of the first speed increaser 6 is between 1 / 40 and 1 / 130, the power of the small-power generator 7 is between 5MW and 10MW, the speed increase ratio of the second speed increaser 13 is between 1 / 60 and 1 / 150, and the power of the large-power generator 14 is between 6MW and 15MW. These equipment parameters achieve optimal transmission performance and power generation efficiency.

[0036] Furthermore, the large impeller 1a and small impeller 1b, the differential 5, and the first speed increaser 6 are mounted on the wind turbine yaw system 4, which is fixed to the tower 2. The tower 2 is mounted on a floating platform on land or at sea. The wind turbine yaw system 4 described above can adapt to wind forces in different directions.

[0037] Furthermore, the second speed increaser 13 includes a second sun gear 13b, which meshes with a second planetary gear 13a for transmission. The second planetary gear 13a meshes with a second gear ring 13d inside the housing for transmission. The second planetary gear 13a is mounted on a second planetary carrier 13c. Through the aforementioned second speed increaser 13, hydraulic energy can be amplified a second time to drive the high-power generator 14.

[0038] Example 2:

[0039] A control method for a mechanical-hydraulic hybrid transmission dual-rotor wind turbine includes the following steps:

[0040] In a wind turbine, the large impeller 1a and the small impeller 1b are respectively connected to the input end of the differential 5, which combines the power flowing into the two impellers and outputs it through the output shaft of the differential 5. The output end of the differential 5 is connected to the first speed increaser 6. When the wind blows the large impeller 1a and the small impeller 1b to rotate, the wind energy is converted into mechanical energy. The output end of the first speed increaser 6 is connected to the small power generator 7. After the speed is increased by the first speed increaser 6, the small power generator 7 converts the mechanical energy into electrical energy.

[0041] Wind turbines need to maximize the harvesting of wind energy, but the wind direction may change at any time. The nacelle 3 is installed on the yaw system 4 of the wind turbine. When the wind speed and wind direction change, the speed sensor on the top of the nacelle 3 sends the wind speed and wind direction signals to the electronic controller. The electronic controller sends a signal to the yaw system 4 of the wind turbine to make the yaw motor rotate the nacelle 3 so that the large rotor 1a and the small rotor 1b are always facing the wind direction.

[0042] Large impeller 1a and small impeller 1b are respectively connected to the input shaft of differential 5. The wind drives large impeller 1a and small impeller 1b to rotate, which in turn drives the input shaft of differential 5. A stator and rotor are installed inside a small-power generator 7. The output shaft of differential 5 drives the generator rotor to rotate in the stator, cutting magnetic field lines and generating an induced electromotive force, thus converting wind energy into mechanical energy. When the wind speed is lower than the set wind speed standard, the output shaft of differential 5 drives the first speed increaser 6. After the speed increaser 6 increases the speed, the small-power generator 7 converts the mechanical energy into electrical energy. When the wind speed is higher than the set wind speed standard, some of the mechanical energy is converted into electrical energy by the small-power generator 7. The hydraulic transmission system converts the other part of the mechanical energy into hydraulic energy and transmits it to the second speed increaser 13 at the bottom of the tower 2. The second speed increaser 13 converts the hydraulic energy into mechanical energy and increases the speed, which then drives the large-power generator 14 to convert the mechanical energy into electrical energy.

[0043] The hydraulic pump 8 provides pressurized oil to the system, converting mechanical energy into hydraulic energy; the control and regulating device check valve 9 controls the flow direction of the liquid; the safety valve 10 is used to control the pressure of the liquid in the hydraulic transmission system to ensure the stability and safety of the hydraulic transmission system; the oil tank 11 is used to store the liquid in the hydraulic transmission system; the actuator hydraulic motor 12 converts hydraulic energy into mechanical energy output.

Claims

1. A mechanical-hydraulic hybrid transmission type dual-rotor wind turbine generator, characterized in that: The system includes a large impeller (1a), a small impeller (1b), a tower (2), a nacelle (3), a wind turbine yaw system (4), a differential (5), a first speed increaser (6), a small-power generator (7), a hydraulic pump (8), a check valve (9), a safety valve (10), an oil tank (11), a hydraulic motor (12), a second speed increaser (13), and a high-power generator (14). The large impeller (1a) and the small impeller (1b) are respectively connected to the input shaft of the differential (5), and the output shaft of the differential (5) is connected to the first speed increaser. Speedbox (6), the output shaft of the first speedbox (6) is connected to the small power generator (7), the wind turbine yaw system (4) is installed between the first speedbox (6) and the tower (2), the transmission method adopts mechanical-hydraulic hybrid transmission, the hydraulic transmission system includes hydraulic pump (8), check valve (9), safety valve (10), oil tank (11) and hydraulic motor (12), the output shaft of hydraulic motor (12) is connected to the second speedbox (13), and the output shaft of the second speedbox (13) is connected to the high power generator (14); The first speed increaser (6) includes a first sun gear (6b), which meshes with a first planet gear (6a) for transmission. The first planet gear (6a) meshes with a first gear ring (6d) inside the gearbox for transmission. The first planet gear (6a) is mounted on a first planet carrier (6c). A first bevel gear (5a) of a differential (5) is fitted on the main shaft of the first planet carrier (6c). A second bevel gear (6e) is mounted on the other end of the axle of the first sun gear (6b). The large impeller (1a) and small impeller (1b), differential (5) and first speed increaser (6) are installed on the wind turbine yaw system (4), which is fixed on the tower (2), which is installed on a ground or offshore floating platform. The second speed increaser (13) includes a second sun gear (13b), which meshes with a second planet gear (13a) for transmission, and the second planet gear (13a) meshes with a second gear ring (13d) inside the gearbox for transmission. The second planet gear (13a) is mounted on a second planet carrier (13c).

2. The mechanical-hydraulic hybrid transmission type dual-rotor wind turbine generator according to claim 1, characterized in that: During the mechanical-hydraulic hybrid transmission process, when the wind speed is lower than the set wind speed standard, the output shaft of the differential (5) drives the first speed increaser (6). After the speed is increased by the first speed increaser (6), the mechanical energy is converted into electrical energy by the small power generator (7). When the wind speed is higher than the set wind speed standard, part of the mechanical energy is converted into electrical energy by the small power generator (7). The hydraulic transmission system converts the other part of the mechanical energy into hydraulic energy and transmits it to the second speed increaser (13) at the bottom of the tower (2). After the speed is increased by the second speed increaser (13), the mechanical energy is converted into electrical energy by the large power generator (14).

3. The mechanical-hydraulic hybrid transmission type dual-rotor wind turbine generator according to claim 1, characterized in that: The growth rate of the first speed increaser (6) is between 1 / 40 and 1 / 130, the power of the small power generator (7) is between 5MW and 10MW, the growth rate of the second speed increaser (13) is between 1 / 60 and 1 / 150, and the power of the large power generator (14) is between 6MW and 15MW.

4. The control method for a mechanical-hydraulic hybrid transmission type dual-rotor wind turbine generator according to any one of claims 1-3, characterized in that, Includes the following steps: In a wind turbine, the large impeller (1a) and the small impeller (1b) are respectively connected to the input end of the differential (5) to combine the power flowing into the two impellers and output it through the output shaft of the differential (5). The output end of the differential (5) is connected to the first speed increaser (6). When the wind blows the large impeller (1a) and the small impeller (1b) to rotate, the wind energy is converted into mechanical energy. The output end of the first speed increaser (6) is connected to the small power generator (7). After the speed is increased by the first speed increaser (6), the small power generator (7) converts the mechanical energy into electrical energy. Wind turbines need to acquire wind energy to the maximum extent, but the wind direction may change at any time. The nacelle (3) is installed on the yaw system (4) of the wind turbine. When the wind speed and wind direction change, the speed sensor on the top of the nacelle (3) sends the wind speed and wind direction signals to the electronic controller. The electronic controller sends a signal to the yaw system (4) of the wind turbine to make the yaw motor rotate the nacelle (3) so that the large impeller (1a) and the small impeller (1b) are always facing the wind direction.

5. The control method for a mechanical-hydraulic hybrid transmission type dual-rotor wind turbine generator according to claim 4, characterized in that, The large impeller (1a) and the small impeller (1b) are respectively connected to the input shaft of the differential (5). The wind drives the large impeller (1a) and the small impeller (1b) to rotate. The large impeller (1a) and the small impeller (1b) drive the input shaft of the differential (5). The small power generator (7) is equipped with a stator and a rotor. The output shaft of the differential (5) drives the generator rotor to rotate in the stator, making a cutting motion of magnetic field lines, thereby generating an induced electromotive force, and the wind energy is converted into mechanical energy. When the wind speed is lower than the set wind speed standard, the output shaft of the differential (5) The first speed increaser (6) drives the first speed increaser (6) to increase the speed, and then the small power generator (7) converts the mechanical energy into electrical energy. When the wind speed is higher than the set wind speed standard, part of the mechanical energy is converted into electrical energy by the small power generator (7). The hydraulic transmission system converts the other part of the mechanical energy into hydraulic energy and transmits it to the second speed increaser (13) at the bottom of the tower (2). The second speed increaser (13) converts the hydraulic energy into mechanical energy and increases the speed, and then drives the large power generator (14) to convert the mechanical energy into electrical energy.

6. The control method for a mechanical-hydraulic hybrid transmission dual-rotor wind turbine generator according to claim 4, characterized in that, The hydraulic pump (8) provides pressurized oil to the system, converting mechanical energy into hydraulic energy; the control and regulating device check valve (9) controls the flow direction of the liquid; the safety valve (10) is used to control the pressure of the liquid in the hydraulic transmission system, ensuring the stability and safety of the hydraulic transmission system; the oil tank (11) is used to store the liquid in the hydraulic transmission system; the actuator hydraulic motor (12) converts hydraulic energy into mechanical energy output.

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