An efficient and reliable composite drive system and operation control method for large wind turbines

Abstract

The present invention provides an efficient and reliable composite drive system and operation control method for large wind turbines. The composite drive system includes two parts: a mechanical drive system and a hydraulic drive system. The mechanical drive system is arranged inside the nacelle at the top of the wind turbine. After parallel-stage power splitting, part of the power is transmitted to the second generator at the bottom of the tower through the hydraulic drive system. The hydraulic drive system is located inside the tower of the wind turbine. The composite drive chain is suitable for natural environments under different wind speeds, integrating the advantages of mechanical drive and hydraulic drive. The two complement each other, can improve the efficiency, utilization rate and reliability of the wind turbine, and ensure that the wind turbine is always in the optimal power generation state.

Description

Technical Field

[0001] The present invention belongs to the technical field of wind power generation equipment, and particularly relates to an efficient and reliable composite drive system for large wind turbines and an operation control method thereof. Background Art

[0002] As is well known in the industry, the drive chain of a traditional wind turbine mainly includes a main shaft, a gearbox, and a generator, and the drive mode is only a single mechanical drive. This drive mode has a simple structure, a long drive chain, and with the increase of power, the weight of the nacelle increases significantly, which is not suitable for large megawatt wind turbines, especially offshore floating wind turbines. Summary of the Invention

[0003] In view of the above defects or improvement requirements of the prior art, the present invention provides an efficient and reliable composite drive system for large wind turbines and an operation control method thereof. The composite drive chain is suitable for natural environments under different wind speeds, integrating the advantages of mechanical drive and hydraulic drive. The two complement each other, can improve the efficiency, utilization rate and reliability of the wind turbine, and ensure that the wind turbine is always in the optimal power generation state.

[0004] To achieve the above technical features, the object of the present invention is realized as follows: An efficient and reliable composite drive system for large wind turbines, the composite drive system includes two parts: a mechanical drive system and a hydraulic drive system;

[0005] The mechanical drive system is arranged inside the nacelle at the top of the wind turbine. After parallel-stage power splitting, part of the power is transmitted to the second generator at the bottom of the tower through the hydraulic drive system;

[0006] The hydraulic drive system is located inside the tower of the wind turbine.

[0007] The mechanical drive system consists of a hub, a main shaft, a gearbox, and a first generator, forming an integrated compact structure;

[0008] The main shaft is installed on the main shaft bearing seat and forms a three-point support with two torque arms of the gearbox, bearing the axial force and torsional load from the impeller; the main shaft bearing seat is fixed inside the nacelle;

[0009] The main shaft is fixedly connected to the planet carrier inside the gearbox;

[0010] The housing of the gearbox is connected together by fastening bolts with a front end cover, an internal gear ring, a middle housing, and a generator housing. The front end cover cooperates with the planet carrier, the middle housing connects the internal gear ring and the housing of the first generator, and the rear housing is the housing of the first generator;

[0011] The sun gear shaft of the gearbox integrates a large gear and the rotor of the first generator and forms a coaxial design;

[0012] The gearbox is a first-stage planetary drive and a first-stage parallel shaft drive. Among them, the power output by the first-stage planetary drive is directly driven by the sun gear shaft to the first generator, and another part of the power is meshed by the large gear and the small gear on the sun gear shaft of the first-stage parallel shaft drive, and then the power is split into the hydraulic transmission system.

[0013] The main shaft adopts a short main shaft and is supported by double-row tapered roller bearings.

[0014] The hydraulic transmission system outputs power from the small gear. The output end of the small gear is connected to the electromagnetic clutch through a torque converter. The electromagnetic clutch is connected to the hydraulic pump. The hydraulic pump is connected to the motor through a pipeline. The output shaft of the motor is connected to the second generator.

[0015] The hydraulic motor and the second generator are located at the bottom of the tower barrel. The hydraulic motor is located inside the tower barrel, and the second generator is located outside the tower barrel and fixed on the foundation.

[0016] The first generator and the second generator are medium-speed permanent magnet synchronous generators.

[0017] The planet carrier and the main shaft are connected through a shrink disc device. Three planet gears are installed on the planet carrier, and the internal gear ring is fixed. The power is output from the sun gear shaft; the internal gear ring is connected to the front end cover and the middle box body through fastening bolts;

[0018] The sun gear shaft adopts a hollow shaft structure.

[0019] The nacelle is supported by a yaw bearing and a tower barrel. The tower barrel is fixedly connected to the foundation through a foundation flange.

[0020] The planet carrier and the sun gear shaft are respectively rotationally supported inside the box body through two groups of tapered roller bearings.

[0021] An operation control method for an efficient, reliable and large-scale wind turbine composite drive system includes the following steps:

[0022] The blades convert wind energy into mechanical energy. The power is split by the planet gears after passing through the planet carrier, and then converges to the sun gear shaft. A part of the power is output through the sun gear shaft to drive the first generator to generate electricity;

[0023] When the external wind speed is relatively high, the main control system of the wind turbine controls the electromagnetic clutch to work. At this time, part of the power is split from the parallel-stage small gear, and another part of the power is meshed by the large gear and the small gear on the sun gear shaft to split the power into the hydraulic transmission system. At this time, the power passes through the torque converter, the electromagnetic clutch, the hydraulic pump, the hydraulic pipeline and the hydraulic motor, and finally flows into the second generator to drive the second generator to generate electricity.

[0024] Generally speaking, compared with the prior art through the above technical solutions conceived by the present invention, an efficient and reliable composite drive system and operation control method for large wind turbines provided by the present invention mainly have the following beneficial effects:

[0025] 1. The composite drive system described in the present invention is composed of a mechanical drive system and a hydraulic drive system. The two complement each other to improve the drive efficiency and reliability of the drive system.

[0026] 2. Since the main components of the main drive chain structure of the mechanical drive system of the present invention adopt a coaxial design, the structure is compact and the reliability is relatively high; the installation method is flexible, the assembly error is small, and the coaxial design can ensure the alignment accuracy.

[0027] 3. According to the external wind speed and wind speed data, the main control system of the wind turbine controls the separation and engagement of the electromagnetic clutch, so that the hydraulic drive system is put into operation, ensuring that the wind turbine is in the best power generation state under different wind conditions.

[0028] 4. By integrating the advantages of mechanical drive and hydraulic drive, the volume and weight of the gearbox and generator are reduced, the overall power of the machine is guaranteed, and the power generation efficiency, utilization rate and reliability of the wind turbine are improved.

[0029] 5. The layout type of the drive chain structure of the present invention is extremely compact, with the characteristics of small size and light weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below with reference to the drawings and embodiments.

[0031] Figure 1 is a schematic diagram of the overall structure of an efficient and reliable composite drive system for large wind turbines of the present invention.

[0032] Figure 2 is a partial cross-sectional view of an efficient and reliable composite drive system for large wind turbines of the present invention.

[0033] In the figure: 1 fastening bolt, 2 planetary gear, 3 planetary carrier, 4 sun gear shaft, 5 tapered roller bearing, 6 pinion gear, 7 large gear, 8 housing, 9 first generator, 10 hydraulic pump, 11 electromagnetic clutch, 12 hydraulic torque converter, 13 gearbox, 14 hub, 15 main shaft, 16 main shaft bearing seat, 17 yaw bearing, 18 nacelle, 19 tower barrel, 20 hydraulic pipeline, 21 hydraulic motor, 22 second generator, 23 foundation. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The embodiments of the present invention will be further described below with reference to the drawings.

[0035] Embodiment 1:

[0036] SeeFigure 1-2 , a highly efficient and reliable composite drive system for large wind turbines. The composite drive system includes two parts: a mechanical drive system and a hydraulic drive system. The mechanical drive system is arranged inside the nacelle 18 at the top of the wind turbine. After parallel-stage power splitting, part of the power is transmitted to the second generator 22 at the bottom of the tower barrel 19 through the hydraulic drive system. The hydraulic drive system is located inside the tower barrel 19 of the wind turbine. By adopting the above composite drive system, it makes full use of the mechanical and hydraulic composite drive, and has the characteristics of high utilization rate, high reliability, light nacelle weight, strong stability, etc., and can effectively adapt to complex external environments.

[0037] Furthermore, the mechanical drive system consists of a hub 14, a main shaft 15, a gearbox 13 and a first generator 9, forming an integrated compact structure. The main shaft 15 is installed on the main shaft bearing seat 16 and forms a three-point support with the two torque arms of the gearbox 13, bearing the axial force and torsional load from the impeller. The main shaft bearing seat 16 is fixed inside the nacelle 18. The main shaft 15 is fixedly connected to the planet carrier 3 inside the gearbox 13. The housing 8 of the gearbox 13 is connected together by fastening bolts 1 from the front end cover, internal gear ring, middle housing and generator housing. The front end cover cooperates with the planet carrier 3. The middle housing connects the internal gear ring and the housing of the first generator 9. The rear housing is the housing of the first generator 9. During the working process of the above mechanical drive system, the wind energy is converted into mechanical energy by the blades. The power is split by the planet gears 2 after passing through the planet carrier 3, and then converges to the sun gear shaft 4. Part of the power is output through the sun gear shaft to drive the first generator 9 to generate electricity.

[0038] Furthermore, the sun gear shaft 4 of the gearbox 13 integrates a large gear 7 and the rotor of the first generator 9 and adopts a coaxial design. The coaxial design makes the structural form extremely compact.

[0039] Furthermore, the gearbox 13 is a one-stage planetary drive and a one-stage parallel shaft drive. Among them, the power output by the one-stage planetary drive directly drives the first generator 9 by the sun gear shaft 4, and another part of the power is meshed by the large gear 7 on the sun gear shaft 4 of the one-stage parallel shaft drive with the small gear 6, and then the power is split to the hydraulic drive system.

[0040] Furthermore, the main shaft 15 adopts a short main shaft and is supported by double-row tapered roller bearings. By adopting a short main shaft, the integrated structure of the gearbox and the generator is extremely compact.

[0041] Further, the hydraulic transmission system outputs power through the pinion gear 6. The output end of the pinion gear 6 is connected to the electromagnetic clutch 11 through the torque converter 12. The electromagnetic clutch 11 is connected to the hydraulic pump 10. The hydraulic pump 10 is connected to the motor 21 through the pipeline 20. The output shaft of the motor 21 is connected to the second generator 22. The mechanical power part is shunted to the hydraulic transmission through the hydraulic transmission system, and then the hydraulic power generation is carried out. The electromagnetic clutch 11 is connected to the hydraulic pump 10 to change the power transmission path of the transmission chain, enabling the wind turbine to be in the optimal power generation state at different wind speeds.

[0042] Through the above hydraulic transmission system, during the specific working process, when the external wind speed is relatively high, the main control system of the wind turbine controls the electromagnetic clutch 11 to work. At this time, part of the power is shunted from the parallel-stage pinion gear, and the second generator 22 is driven to generate electricity through the hydraulic transmission; the torque converter 12 is respectively connected to the pinion shaft and the electromagnetic clutch 11 through the coupling, driving the hydraulic pump 10 to work to generate high-speed moving fluid, driving the hydraulic motor 21 to rotate, and thus driving the second generator 22 to generate electricity; the hydraulic pump 10 can convert the mechanical energy input by the electromagnetic clutch 11 into fluid hydraulic energy and kinetic energy, and then the hydraulic motor 21 converts the fluid hydraulic energy into mechanical energy, and then through the second generator 22, it is converted into electrical energy; the second generator 22 is located at the bottom of the tower barrel 19 and is used to convert the mechanical energy transmitted by the hydraulic motor 21 into electrical energy and cooperate with the first generator 9 integrated in the box body 8 to assist in power generation.

[0043] Further, the hydraulic motor 21 and the second generator 22 are located at the bottom of the tower barrel 19. The hydraulic motor 21 is located inside the tower barrel 19, and the second generator 22 is located outside the tower barrel 19 and is fixed on the foundation 23. Through the above layout structure, it is convenient for subsequent maintenance and detection of the hydraulic motor 21 and the second generator 22.

[0044] Further, the first generator 9 and the second generator 22 are medium-speed permanent magnet synchronous generators.

[0045] Further, the planet carrier 3 and the main shaft 15 are connected through a shrink disk device. Three planet gears 2 are installed on the planet carrier 3, the internal gear ring is fixed, and the power is output from the sun gear shaft 4; the internal gear ring is connected to the front end cover and the middle box body through the fastening bolts 1; through the above planetary transmission, the rotational power of the impeller can be transmitted to the sun gear shaft 4, and then drive the corresponding

[0046] Further, the sun gear shaft 4 adopts a hollow shaft structure. By adopting the hollow shaft structure, the centering accuracy is ensured, and thus the transmission stability is improved.

[0047] Further, the nacelle 18 is supported by the yaw bearing 17 and the tower barrel 19, and the tower barrel 19 is fixedly connected to the foundation 23 through the foundation flange.

[0048] Furthermore, the planet carrier 3 and the sun gear shaft 4 are respectively rotationally supported inside the housing 8 by two sets of tapered roller bearings 5. The tapered roller bearings 5 ensure that a certain axial force and radial force can be borne.

[0049] Working principle of the present invention:

[0050] The gear transmission system is a one-stage planetary drive and a one-stage parallel shaft drive. The power is first split and then converged through the planetary gear train and output from the sun gear shaft 4 to drive the first generator 9 to generate electricity; when the external wind speed is relatively high, the main control system of the wind turbine controls the electromagnetic clutch 11 to work. At this time, part of the power is split from the parallel stage pinion, and the hydraulic transmission is used to drive the second generator 22 to generate electricity; the hydraulic torque converter 12 is respectively connected to the pinion shaft and the electromagnetic clutch 11 through couplings to drive the hydraulic pump 10 to work to generate a fluid with high-speed motion, driving the hydraulic motor 21 to rotate, thereby driving the second generator 22 to generate electricity; the hydraulic pump 10 can convert the mechanical energy input by the electromagnetic clutch 11 into fluid hydraulic energy and kinetic energy, and then the hydraulic motor 21 converts the fluid hydraulic energy into mechanical energy, and then the second generator 22 converts it into electrical energy; the second generator 22 is located at the bottom of the tower barrel 19 to convert the mechanical energy transmitted by the hydraulic motor 21 into electrical energy and cooperate with the first generator 9 integrated in the housing 8 to assist in generating electricity. Thus, the efficient utilization of energy is realized.

[0051] Embodiment 2:

[0052] An operation control method for an efficient and reliable large wind turbine composite drive system includes the following steps:

[0053] The blades convert wind energy into mechanical energy. The power passes through the planet carrier 3 and is split by the planet gears 2, and then converges to the sun gear shaft 4. Part of the power is output through the sun gear shaft 4 to drive the first generator 9 to generate electricity;

[0054] When the external wind speed is relatively high, the main control system of the wind turbine controls the electromagnetic clutch 11 to work. At this time, part of the power is split from the parallel stage pinion 6, and another part of the power is meshed with the pinion 6 through the large gear 7 on the sun gear shaft 4 to split the power into the hydraulic transmission system. At this time, the power passes through the hydraulic torque converter 12, the electromagnetic clutch 11, the hydraulic pump 10, the hydraulic pipeline 20 and the hydraulic motor 21, and finally flows into the second generator 22 to drive the second generator 22 to generate electricity.

Claims

1. An efficient and reliable composite drive system for large wind turbines, characterized in that, The composite drive system includes two parts: a mechanical drive system and a hydrodynamic drive system; The mechanical drive system is arranged inside the nacelle (18) at the top of the wind turbine. After parallel-stage power splitting, part of the power is transmitted to the second generator (22) at the bottom of the tower barrel (19) through the hydrodynamic drive system; The hydrodynamic drive system is located inside the tower barrel (19) of the wind turbine; The mechanical drive system consists of a hub (14), a main shaft (15), a gearbox (13) and a first generator (9), forming an integrated compact structure; The main shaft (15) is installed on the main shaft bearing seat (16) and forms a three-point support with two torque arms of the gearbox (13), bearing the axial force and torsional load from the impeller; the main shaft bearing seat (16) is fixed inside the nacelle (18); The main shaft (15) is fixedly connected to the planet carrier (3) inside the gearbox (13); The housing (8) of the gearbox (13) is connected together by fastening bolts (1) from the front end cover, the internal gear ring, the middle housing and the generator housing. The front end cover cooperates with the planet carrier (3), the middle housing connects the internal gear ring and the housing of the first generator (9), and the rear housing is the housing of the first generator (9); The sun gear shaft (4) of the gearbox (13) integrates a large gear (7) and the rotor of the first generator (9) and adopts a coaxial design; The gearbox (13) is a one-stage planetary drive and a one-stage parallel shaft drive. Among them, the power output by the one-stage planetary drive is directly driven by the sun gear shaft (4) to the first generator (9), and another part of the power is meshed by the large gear (7) on the sun gear shaft (4) of the one-stage parallel shaft drive with the small gear (6), and then the power is split to the hydrodynamic drive system; The hydrodynamic drive system outputs power from the small gear (6). The output end of the small gear (6) is connected to the electromagnetic clutch (11) through a hydrodynamic torque converter (12). The electromagnetic clutch (11) is connected to the hydraulic pump (10). The hydraulic pump (10) is connected to the hydraulic motor (21) through a pipeline (20). The output shaft of the hydraulic motor (21) is connected to the second generator (22).

2. The composite drive system for a high-efficiency and reliable large-scale wind turbine according to claim 1, characterized in that The main shaft (15) adopts a short main shaft and is supported by double-row tapered roller bearings.

3. The composite drive system for a highly efficient and reliable large-scale wind turbine according to claim 2, characterized in that, The hydraulic motor (21) and the second generator (22) are located at the bottom of the tower barrel (19). The hydraulic motor (21) is located inside the tower barrel (19), and the second generator (22) is located outside the tower barrel (19) and is fixed on the foundation (23).

4. The composite drive system for a high-efficiency and reliable large-scale wind turbine according to claim 3, wherein, The first generator (9) and the second generator (22) are medium-speed permanent magnet synchronous generators.

5. The composite drive system of a highly efficient and reliable large wind turbine according to claim 4, characterized in that, The planet carrier (3) and the main shaft (15) are connected by a shrinking device. Three planet gears (2) are installed on the planet carrier (3), the internal gear ring is fixed, and the power is output from the sun gear shaft (4); the internal gear ring is connected to the front end cover and the middle housing by fastening bolts (1); The sun gear shaft (4) adopts a hollow shaft structure.

6. The composite drive system for a highly efficient and reliable large wind turbine according to claim 5, wherein, The nacelle (18) is supported by a yaw bearing (17) and the tower barrel (19). The tower barrel (19) is fixedly connected to the foundation (23) through a foundation flange.

7. The composite drive system of a highly efficient and reliable large wind turbine according to claim 6, characterized in that, The planet carrier (3) and the sun gear shaft (4) are respectively rotationally supported inside the housing (8) by two sets of tapered roller bearings (5).

8. The operation control method of the high-efficiency and reliable large-scale wind turbine composite drive system according to claim 7, characterized in that The method comprises the following steps: The blades convert wind energy into mechanical energy. The power is shunted by the planet gears (2) after passing through the planet carrier (3), and then converges to the sun gear shaft (4). A part of the power is output through the sun gear shaft (4) to drive the first generator (9) to generate electricity; When the external wind speed is relatively high, the main control system of the wind turbine controls the electromagnetic clutch (11) to work. At this time, a part of the power is shunted from the parallel stage pinion gear (6). A part of the power is meshed with the pinion gear (6) through the large gear (7) on the sun gear shaft (4) to shunt the power to the hydraulic transmission system. At this time, the power passes through the hydraulic torque converter (12), the electromagnetic clutch (11), the hydraulic pump (10), the hydraulic pipeline (20) and the hydraulic motor (21), and finally flows into the second generator (22) to drive the second generator (22) to generate electricity.

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