Transmission chain, wind turbine generator set and power generation method thereof

Abstract

The present invention discloses a transmission chain, a wind power generation set and a power generation method thereof. The transmission chain includes a main gearbox, a speed regulation gearbox and a motor set. The main gearbox includes a main input shaft, a main bearing, a differential planetary stage, a quasi-planetary stage and a common planetary stage. The motor set includes a synchronous generator and a speed regulation motor. The speed regulation gearbox adopts differential planetary gear transmission. This transmission chain adopts differential planetary and quasi-planetary gear transmissions to shunt and converge the power from the wind turbine, reducing the loads on the ring gear of the quasi-planetary stage and the planet carrier of the differential planetary stage and improving the reliability. In some embodiments, the main bearing adopts a double-row tapered roller bearing, making the layout of the hub, the main gearbox and the main frame more compact, effectively shortening the length of the transmission chain and reducing the bending moment generated by the weight of the wind turbine on the tower. A speed regulation gearbox is adopted, and by controlling the speed of the speed regulation motor, the speed of the synchronous generator is made constant, realizing the direct grid connection of the electric energy generated by the synchronous generator, and the power quality is high.

Description

Technical Field

[0001] The invention relates to a transmission chain, a wind power generator set and a power generation method thereof. Background Art

[0002] As the proportion of wind turbines in the power grid increases, the power grid has higher and higher requirements for the quality of power connected to the power grid by wind turbines. The Chinese patent application publication number CN202215429U has disclosed a control system for a differential gearbox speed-regulating synchronous wind turbine generator set. By adding a differential planetary speed-regulating gearbox to the output end of the conventional three-stage gearbox to replace the converter, the synchronous generator is used to generate electricity, so that the generated electricity can be directly connected to the power grid, and the quality of the electricity is also improved. However, the differential planetary speed-regulating gearbox disclosed in the patent is only applicable to the case where the third stage of the main gearbox is a parallel stage.

[0003] For conventional wind turbines, the main gearbox in the transmission chain is composed of a one-stage planetary, two-stage parallel or two-stage planetary, one-stage parallel gear transmission. The power from the wind wheel is completely concentrated and transmitted to the first planetary stage of the main gearbox, causing the first planetary stage to bear a larger load and requiring higher performance, which results in a higher overall cost of the gearbox.

[0004] The semi-direct-drive wind turbines currently on the market have a main gearbox in the transmission chain composed of a three-stage planetary gear transmission. The generator is integrated with the main gearbox. The generator uses a medium-speed permanent magnet motor. A full-power converter is arranged between the medium-speed permanent magnet motor and the power grid. On the one hand, the full-power converter is expensive, and on the other hand, the power quality is poor. Summary of the invention

[0005] In order to solve at least one of the above-mentioned technical problems, the present invention provides a transmission chain, a wind turbine generator set and a power generation method thereof.

[0006] The present invention solves the above technical problems through the following technical solutions:

[0007] The present invention discloses a transmission chain, which comprises a main gearbox, a speed regulating gearbox and a motor group; the main gearbox comprises a main input shaft, a main bearing, a differential planetary stage, a quasi-planetary stage and a main output shaft; the speed regulating gearbox adopts a differential planetary gear transmission; the motor group comprises a synchronous generator and a variable frequency motor, the main input shaft is connected to the quasi-planetary stage and the differential planetary stage at the same time, the quasi-planetary stage outputs to the differential planetary stage, the differential planetary stage is connected to the main output shaft, the main output shaft is connected to the speed regulating gearbox, and the speed regulating gearbox is connected to the synchronous generator and the variable frequency motor at the same time.

[0008] Preferably, the differential planetary stage includes a differential planetary stage sun gear, a differential planetary stage planet carrier, a differential planetary stage planetary gear and a differential planetary stage ring gear, the differential planetary stage planet carrier is connected to the main input shaft, and the differential planetary stage ring gear is connected to the quasi-planetary stage.

[0009] Preferably, the quasi-planetary stage comprises a quasi-planetary stage sun gear, a quasi-planetary stage planet carrier, a quasi-planetary stage planetary gear and a quasi-planetary stage ring gear, wherein the quasi-planetary stage ring gear is connected to the main input shaft, and the quasi-planetary stage sun gear is connected to the differential planetary stage ring gear.

[0010] In this scheme, after the power from the wheel hub is transmitted to the main input shaft, part of it is transmitted to the quasi-planetary ring gear and part of it is transmitted to the differential planetary planet carrier; the power transmitted to the quasi-planetary ring gear is transmitted to the differential planetary ring gear through the quasi-planetary sun gear after the quasi-planetary gear transmission increases the speed and reduces the torque; the power transmitted to the differential planetary planet carrier and the power of the differential planetary ring gear act together on the differential planetary planet gear and are transmitted to the differential planetary sun gear for output. The main gearbox adopts differential planetary and quasi-planetary gear transmission to realize power splitting and merging, which reduces the load of the quasi-planetary ring gear and the differential planetary planet carrier, so that the power density of the main gearbox is increased, the volume is reduced, and the reliability is improved, thereby reducing the overall cost of the main gearbox.

[0011] Preferably, the differential planetary stage planetary gear is fixed to the differential planetary stage planetary carrier via a flexible pin;

[0012] And / or, the quasi-planetary planetary gear is fixed to the quasi-planetary planetary carrier via a flexible pin.

[0013] In this solution, the above-mentioned structural form is adopted so that the load is evenly distributed among the planetary gears, achieving load balancing, thereby increasing the life of the gears.

[0014] Preferably, the quasi-planetary sun gear is connected to the differential planetary ring gear via a conical disk; and / or, the quasi-planetary sun gear and the differential planetary ring gear are integral floating parts.

[0015] In this solution, the quasi-planetary sun gear and the differential planetary ring gear are connected by a conical disk, and the connection structure is simple. By setting the quasi-planetary sun gear and the differential planetary ring gear as floating parts, the tooth surface contact is more uniform and the force is better, thereby improving the reliability of the gear set.

[0016] Preferably, the outer ring of the main bearing is connected to the main input shaft, and the inner ring of the main bearing is connected to the quasi-planetary planet carrier.

[0017] In this solution, the above-mentioned structural form is adopted, and the differential planetary stage is arranged at the front end of the main bearing, the quasi-planetary stage is arranged inside the main bearing, and the ordinary planetary stage is arranged at the rear end of the main bearing. The bearing seat is eliminated, the length of the transmission chain is shortened, the transmission chain is made more compact, and the overall cost is reduced.

[0018] Preferably, the main bearing is a double-row tapered bearing.

[0019] Preferably, the transmission chain also includes a common planetary stage, which includes a common planetary stage sun gear, a common planetary stage planet carrier, a common planetary stage planetary gear and a common planetary stage ring gear, the common planetary stage planet carrier is respectively connected to the differential planetary stage sun gear and the quasi-planetary stage sun gear, and the common planetary stage sun gear is connected to the speed regulating gear box.

[0020] Preferably, the speed regulating gearbox comprises a speed regulating stage sun gear, a speed regulating stage planetary carrier, a speed regulating stage planetary gear and a speed regulating stage ring gear; the speed regulating stage planetary carrier is connected to the ordinary planetary stage sun gear; the speed regulating stage ring gear is connected to the synchronous generator; and the speed regulating stage sun gear is connected to the variable frequency motor.

[0021] In this scheme, the power from the speed-regulating planetary carrier, the speed-regulating sun gear, and the speed-regulating ring gear is gathered at the speed-regulating planetary gear. The speed-regulating planetary carrier is the input, the speed-regulating ring gear is the output, and the speed-regulating sun gear can be both the input and the output. The speed-regulating planetary carrier is connected to the ordinary planetary sun gear, and the power of the wind turbine rotor transmitted by the main gearbox is transmitted to the speed-regulating planetary gear; the speed-regulating sun gear is connected to the variable frequency motor and obtains the speed regulating speed from the variable frequency motor. The speed-regulating planetary gear synthesizes the input speed of the speed-regulating planetary carrier and the speed regulating speed of the speed-regulating sun gear to form a constant output speed of the speed-regulating ring gear and output it to the synchronous generator. To ensure that the speed of the synchronous generator remains constant, the working mode of the variable frequency motor must change according to the change of the wind rotor speed. When the wind rotor speed is lower than the critical speed, the variable frequency motor acts as a generator, and drives the speed regulating stage sun gear to input power to the speed regulating stage planetary gear; when the energy captured by the wind rotor exceeds the capacity of the variable frequency motor, the synchronous generator brake system is released, and the variable frequency motor acts as an electric speed regulator to ensure that the synchronous generator input speed is stable, and the synchronous generator starts working; when the wind rotor speed reaches a certain time, the variable frequency motor acts as a generator speed regulator and generates electricity simultaneously with the synchronous generator.

[0022] Preferably, the motor group also includes a synchronous generator braking system and a speed regulating motor braking system.

[0023] The present invention further discloses a wind turbine generator set, which includes the transmission chain as described above.

[0024] Preferably, the wind turbine generator set further comprises a wind wheel, and the wind wheel and the main input shaft are both connected to the outer ring of the main bearing;

[0025] And / or, the wind turbine generator set further includes a main frame, the quasi-planetary stage includes a quasi-planetary stage planetary frame, and the main frame is connected to the quasi-planetary stage planetary frame and the inner ring of the main bearing.

[0026] In this scheme, the above-mentioned structural form is adopted, and the wind drives the wind rotor to rotate, and then transmits the power to the main input shaft through the outer ring of the main bearing. The differential planetary stage is arranged in the rear cavity of the hub, the quasi-planetary stage is arranged in the inner ring cavity of the main bearing, and the ordinary planetary stage is arranged in the front cavity of the main frame, which effectively utilizes the relevant space, shortens the length of the nacelle, and reduces the cost; at the same time, the main frame of the wind turbine generator set, the differential planetary stage planetary frame flange, and the inner ring of the main bearing are fixed together, shortening the distance between the center of the wind rotor and the center of the tower, and reducing the bending moment caused by the weight of the wind rotor on the tower.

[0027] Preferably, the wind turbine generator set further comprises a wind rotor locking device and a matching wind rotor locking plate, wherein the wind rotor locking device is arranged on the main frame, and the wind rotor locking plate is connected to the outer ring of the main bearing.

[0028] In this solution, the above-mentioned structural form is adopted, and the rotation of the main bearing can be controlled through the cooperation between the wind wheel locking device and the wind wheel locking plate, thereby locking the wind wheel.

[0029] The present invention further discloses a method for generating electricity of a wind turbine generator set, which utilizes a transmission chain and / or a wind turbine generator set, and the method for generating electricity includes: the energy captured by the wind wheel is transmitted through the transmission chain; when the power of the energy captured by the above-mentioned wind wheel is lower than a first critical power, the variable frequency motor is used as a generator, and the variable frequency motor generates electricity; when the power of the energy captured by the wind wheel is higher than the power of the first critical captured energy, the variable frequency motor is used as an electric speed regulator, and the synchronous generator generates electricity, and the variable frequency motor is used to adjust the input speed of the synchronous generator; when the power of the energy captured by the wind wheel is higher than the second critical power, the variable frequency motor is used as a generator speed regulator, and the variable frequency motor and the synchronous generator generate electricity simultaneously.

[0030] In this solution, the above-mentioned structural form is adopted to make the working mode of the variable frequency motor flexible and diverse. The main motor can be allowed to rest when the wind is light, and the input speed of the main motor can be stabilized when it is used as an electric motor at medium wind speed. When the wind speed is high, it can be used as a generator, which can not only stabilize the input speed of the main motor but also reduce the burden on the main motor.

[0031] Preferably, when the power of energy captured by the wind wheel is lower than a first critical power, the synchronous generator brake system is locked.

[0032] In this solution, the above-mentioned structural form is adopted, and by locking the synchronous generator system, when the power of energy captured by the wind wheel is low, the synchronous generator does not need to work, thereby reducing the burden on the synchronous generator.

[0033] The positive improvement effects of the embodiments of the present invention are:

[0034] The differential planetary and quasi-planetary gear transmission divides and merges the power from the wind wheel, reducing the load on the quasi-planetary ring gear and the differential planetary planet carrier, thereby increasing the power density of the main gearbox, reducing the volume, and improving the reliability; the quasi-planetary stage of the main gearbox is arranged inside the main bearing, so that the differential planetary stage of the main gearbox is arranged in the rear cavity of the hub, and the basic planetary stage of the main gearbox, the speed regulating gearbox, the synchronous generator, and the variable frequency motor are arranged in the front cavity of the main frame, which effectively shortens the length of the transmission chain and reduces the bending moment of the wind wheel on the tower; due to the addition of the speed regulating gearbox, the speed of the speed regulating stage sun gear can be controlled by changing the speed of the variable frequency motor and the working mode according to the wind wheel speed to ensure that the speed of the speed regulating stage ring gear remains constant, so that the speed of the synchronous generator is stabilized at the synchronous speed, and the frequency of the electricity emitted is consistent with the frequency of the power grid. It does not need to pass through the converter and is directly connected to the grid, with high power quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a schematic diagram of a transmission chain according to an embodiment of the present invention;

[0036] Figure 2 Schematic diagram of a wind turbine generator set according to an embodiment of the present invention.

[0037] Description of reference numerals:

[0038] Wind turbine 100

[0039] Transmission chain 1

[0040] Main gearbox 11

[0041] Differential Planetary Class 111

[0042] Differential planetary gear 1111

[0043] Differential planetary carrier 1112

[0044] Differential planetary gear ring 1113

[0045] Differential planetary sun gear 1114

[0046] Quasi-planetary 112

[0047] Quasi-planetary gear ring 1121

[0048] Quasi-planetary sun gear 1122

[0049] Quasi-planetary planet carrier 1123

[0050] Quasi-planetary gear 1124

[0051] Ordinary planetary level 113

[0052] Ordinary planetary gear 1131

[0053] Ordinary planetary sun gear 1132

[0054] Ordinary planetary gear ring 1133

[0055] Main input shaft 114

[0056] Main bearing 115

[0057] Speed ​​regulating gear box 12

[0058] Speed ​​regulating stage planetary gear 121

[0059] Speed ​​regulating ring gear 122

[0060] Speed ​​regulating stage sun gear 123

[0061] Motor group 13

[0062] Synchronous generator 131

[0063] Frequency conversion motor 132

[0064] Synchronous generator brake system 133

[0065] Variable frequency motor brake system 134

[0066] Wind wheel 2

[0067] Blade 21

[0068] Wheel 22

[0069] Main frame 3

[0070] Wind wheel locking plate 4

[0071] Wind wheel locking device 5

[0072] Inverter 6

[0073] Transformer 7 DETAILED DESCRIPTION

[0074] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0075] like Figure 1 and Figure 2As shown, this embodiment provides a transmission chain 1, which includes a main gearbox 11, a speed-regulating gearbox 12 and a motor group 13. The main gearbox 11 includes a main input shaft 114, a main bearing 115, a differential planetary stage 111, a quasi-planetary stage 112, a normal planetary stage 113 and a main output shaft. The speed-regulating gearbox 12 adopts a differential planetary gear transmission. The motor group 13 includes a synchronous generator 131 and a variable frequency motor 132. The main input shaft 114 is connected to the differential planetary stage 111 and the quasi-planetary stage 112 respectively. The quasi-planetary stage 112 outputs to the differential planetary stage 111. The differential planetary stage 111 is connected to the normal planetary stage 113. The normal planetary stage 113 is connected to the speed-regulating gearbox 12 through the main output shaft. The speed-regulating gearbox 12 is connected to the synchronous generator 131 and the variable frequency motor 132. Specifically, after the power of the hub 22 is input from the main input shaft 114, a part of it is transmitted to the quasi-planetary stage 112, and the other part is transmitted to the differential planetary stage 111. After the output power of the hub 22 is split, it can be combined at the differential planetary stage 111 and transmitted to the common planetary stage 113 through the differential planetary stage 111. With the above structure, the output power of the hub 22 is transmitted to the main gearbox 11 through splitting, thereby reducing the load on the input end of the main gearbox 11 and the performance requirements on the input end, so that the power density of the main gearbox 11 is increased, the volume is reduced, and the reliability is improved, thereby reducing the overall cost of the main gearbox 11.

[0076] See also Figure 1 For understanding, the differential planetary stage 111 includes a differential planetary stage sun gear 1114, a differential planetary stage planet carrier 1112, a differential planetary stage planetary gear 1111 and a differential planetary stage ring gear 1113. The differential planetary stage sun gear 1114 is connected to the main input shaft 114 through the differential planetary stage planet carrier 1112, and the differential planetary stage sun gear 1114 is connected to the quasi-planetary stage 112 through the differential planetary stage ring gear 1113. Specifically, after power is input from the main input shaft 114, a part of the power is transmitted to the differential planetary stage sun gear 1114 through the differential planetary stage planet carrier 1112 and the differential planetary stage planetary gear 1111; the other part of the power is also transmitted to the differential planetary stage sun gear 1114 through the quasi-planetary stage 112 and the differential planetary stage planetary gear 1111. By adopting the above structure, the output power of the hub 22 is transmitted in a split flow, and is combined at the differential planetary stage planetary gear 1111, and is input to the common planetary stage 113 through the differential planetary stage sun gear 1114. By adopting the above structure, along the transmission direction of the output power, the load of the front stage gear train of the differential planetary stage sun gear 1114 is reduced, the performance requirements of the front stage gear train of the differential planetary stage sun gear 1114 are reduced, and the cost of the main gearbox 11 is further reduced.

[0077] In specific use, the differential planetary stage planet carrier 1112 is equivalent to the input end of the differential planetary stage 111, and the power shunting effect reduces the performance requirements of the differential planetary stage planet carrier 1112; in addition, the power input from the collimator stage 112 can also reduce the performance requirements of the differential planetary stage gear ring 1113 due to the power shunting effect. That is, the above-mentioned structural form can not only reduce the performance requirements of the input end, but also reduce the performance requirements of the front stage gear train of the differential planetary stage sun gear 1114 if the differential planetary stage sun gear 1114 has a front stage gear train, so that the power density of the main gear box 11 is increased, the volume is reduced, the reliability is improved, and the cost of the main gear box 11 is further reduced.

[0078] The differential planetary planetary gear 1111 is fixed to the differential planetary planetary carrier 1112 through a flexible pin, and the quasi-planetary planetary gear 1124 is fixed to the quasi-planetary planetary carrier 1123 through a flexible pin. The above structure is adopted to evenly distribute the load between the planetary gears, realize load balancing, and thus improve the life of the gears. In other embodiments, it can also be fixed to the planetary carrier through flexible bolts, which is not further limited here.

[0079] Specifically, each planetary gear of the differential planetary gear 1111 and the quasi-planetary gear 112 adopts a flexible pin structure for load balancing, the flexible pin shaft of the flexible pin structure has an interference fit with its corresponding planetary carrier, the pin sleeve of the flexible pin structure has an interference fit with the flexible pin shaft, and the pin sleeve is used to support the planetary bearing and planetary gear of the corresponding planetary gear system. When the two tangential forces of the ring gear and the sun gear of each planetary gear system are applied to the planetary gear, the angle winding caused by the bending of the cantilevered flexible pin shaft on the planetary carrier can be offset by the angle winding caused by the bending of the cantilevered pin sleeve at the other end of the flexible pin shaft in the opposite direction, so that each planetary gear floats in parallel, and then the load is evenly distributed between each planetary gear, achieving load balancing, and thus improving the life of the gear.

[0080] See also Figure 1It is understood that the quasi-planetary stage 112 includes a quasi-planetary ring gear 1121, a quasi-planetary sun gear 1122, a quasi-planetary planet carrier 1123 and a quasi-planetary planet gear 1124. The main input shaft 114 is connected to the quasi-planetary sun gear 1122 through the quasi-planetary ring gear 1121 and the quasi-planetary planet gear 1124, and the quasi-planetary sun gear 1122 is connected to the differential planetary ring gear 1113. Through the quasi-planetary sun gear 1122 and the differential planetary ring gear 1113, the power input from the quasi-planetary ring gear 1121 is input to the differential planetary planet gear 1111 through the differential planetary ring gear 1113 after passing through the quasi-planetary planet gear 1124 and the quasi-planetary sun gear 1122. The above-mentioned structural form improves the compactness of the main gearbox 11, thereby reducing the length of the transmission chain 1, so that the power density of the main gearbox 11 is increased, the volume is reduced, the reliability is improved, and the cost of the main gearbox 11 is reduced.

[0081] During specific use, the quasi-planetary ring gear 1121, the quasi-planetary planetary gears 1124 and the quasi-planetary sun gear 1122 in the quasi-planetary stage 112 only transmit the power input from the quasi-planetary stage 112, thereby reducing the performance requirements of the quasi-planetary ring gear 1121, the quasi-planetary planetary gears 1124 and the quasi-planetary sun gear 1122, and also reducing the performance requirements of the main gearbox 11.

[0082] The quasi-planetary sun gear 1122 is connected to the differential planetary gear ring 1113 through a conical disk, which improves the simplicity of the connection. Specifically, the quasi-planetary sun gear 1122 is connected to the differential planetary gear ring 1113 through a conical disk. The whole is not connected and fixed to the related parts by the main bearing 115, and is free in the axial and radial directions (the free movement distance will be limited during the specific design), so they are floating. When meshing with the flexible pin planetary gear, they will adapt to each other during transmission, so that the tooth surface load is better, which can increase the life of the gear. In other embodiments, the quasi-planetary sun gear 1122 can also be connected to the differential planetary gear ring 1113 by bolts or the like, and the connection method is not limited here.

[0083] The quasi-planetary sun gear 1122 and the differential planetary ring gear 1113 are floating parts, which ensure more uniform contact between the tooth surfaces and better force, thereby improving the reliability of the gear set.

[0084] like Figure 1As shown, the outer ring of the main bearing 115 is connected to the main input shaft 114, and the inner ring of the main bearing 115 is connected to the quasi-planetary planet carrier 1123. With the above structure, the main gearbox 11 is arranged at the front end of the main bearing 115, the quasi-planetary stage 112 is arranged inside the main bearing 115, and the ordinary planetary stage 113 is arranged at the rear end of the main bearing 115, the bearing seat is cancelled, the length of the transmission chain 1 is effectively shortened, and the overall cost is reduced. Specifically, the main bearing 115 is a double-row tapered bearing, which further improves the compactness of the transmission chain 1 structure.

[0085] In other embodiments, the main bearing 115 may also be in the form of a tapered roller bearing, etc., which is not limited here.

[0086] The ordinary planetary stage 113 includes ordinary planetary stage planetary gears 1131, ordinary planetary stage ring gears 1133, ordinary planetary stage planet carriers, and ordinary planetary stage sun gears 1132. The ordinary planetary stage planetary gears 1131 are connected to the differential planetary stage 111, the ordinary planetary stage planet carriers are respectively connected to the differential planetary stage sun gears 1114 and the quasi-planetary stage sun gears 1122, and the ordinary planetary stage sun gears 1132 are connected to the speed regulating gearbox 12. Specifically, the ordinary planetary stage planetary gears 1131 are connected to the differential planetary stage 111, and the ordinary planetary stage ring gears 1133 are connected to the ordinary planetary stage planetary gears 1131, so that the rotation of the differential planetary stage 111 can be transmitted to the ordinary planetary stage planetary gears 1131. Since the ordinary planetary stage planetary gears 1131 and the ordinary planetary stage sun gears 1132 are connected to each other, the rotation of the ordinary planetary stage planetary gears 1131 can be transmitted to the ordinary planetary stage sun gears 1132, and then transmitted to the speed regulating gearbox 12 through the ordinary planetary stage sun gears 1132.

[0087] During specific use, the total transmission ratio of the main gearbox 11 can reach 50-100, which improves the overall transmission ratio of the main gearbox 11, allows the main gearbox 11 to adapt to various working environments, increases the output speed of the main gearbox 11, reduces the output torque, makes the motor group 13 smaller, improves the structural compactness of the wind turbine generator set 100, and effectively reduces the cost of the motor group 13.

[0088] The main gearbox 11 is also provided with a rear box body, one end of which is fixedly connected to the quasi-planetary planetary frame 1123, and the other end of the rear box body is connected to the motor group 13. The diameter of the rear box body and the generator is smaller than the diameter of the front flange of the main frame 3.

[0089] See also Figure 1It is understood that the speed regulating gearbox 12 includes a speed regulating stage sun gear 123, a speed regulating stage planetary carrier, a speed regulating stage planetary gear 121 and a speed regulating stage ring gear 122, the speed regulating stage planetary gear 121 is respectively connected to the ordinary planetary stage 113 and the speed regulating stage ring gear 122, the speed regulating stage sun gear 123 is respectively connected to the speed regulating stage planetary gear 121 and the variable frequency motor 132, and the speed regulating stage ring gear 122 is connected to the synchronous generator 131. With the above-mentioned structural form, the ordinary planetary stage 113 transmits the rotation to the speed regulating stage planetary gear 121, and the speed regulating stage planetary gear 121 transmits the rotation to the speed regulating stage ring gear 122. The rotation of the speed regulating stage ring gear 122 drives the synchronous generator 131 to rotate, thereby realizing the power generation of the synchronous generator 131.

[0090] The power from the speed regulating stage planet carrier, the speed regulating stage sun gear 123, and the speed regulating stage ring gear 122 is gathered at the speed regulating stage planet gear 121, the speed regulating stage planet carrier is the input, the speed regulating stage ring gear 122 is the output, and the speed regulating stage sun gear 123 can be both the input and the output. The speed regulating stage planet carrier is connected to the ordinary planetary stage sun gear 1132, and transmits the power of the wind turbine rotor transmitted by the main gear box 11 to the speed regulating stage planet gear 121; the speed regulating stage sun gear 123 is connected to the variable frequency motor 132 and obtains the speed regulating speed from the variable frequency motor 132, and the speed regulating stage planet gear 121 synthesizes the input speed of the speed regulating stage planet carrier and the speed regulating speed of the speed regulating stage sun gear 123 to form a constant output speed of the speed regulating stage ring gear 122 and outputs it to the synchronous generator 131. In order to ensure that the speed of the synchronous generator 131 remains constant, the working mode of the variable frequency motor 132 must change according to the change of the speed of the wind wheel 2. When the speed of the wind wheel 2 is lower than the critical speed, the variable frequency motor 132 is a generator, and the variable frequency motor 132 drives the speed regulating stage sun gear 123 to input power to the speed regulating stage planetary gear 121; when the energy captured by the wind wheel 2 exceeds the capacity of the variable frequency motor 132, the synchronous generator brake system 133 is released, and the variable frequency motor 132 is used as an electric speed regulator to ensure that the input speed of the synchronous generator 131 is stable, and the synchronous generator 131 starts to work; when the speed of the wind wheel 2 reaches a certain time, the variable frequency motor 132 is used as a generator speed regulator to generate electricity simultaneously with the synchronous generator 131.

[0091] See also Figure 1 and Figure 2It is understood that the speed regulating stage ring gear 122 is connected to the power grid through the rotor of the synchronous generator 131. The variable frequency motor 132 is controlled by the frequency converter 6, and the variable frequency motor 132 is connected to the power grid through the frequency converter 6 and the transformer 7 in turn, obtaining electric energy from the power grid or transmitting electric energy to the power grid. Specifically, the synchronous generator 131 adopts a high-voltage motor, and only the insulation level is improved. Since the transformer 7 is omitted, the overall cost is lower. Specifically, the variable frequency motor 132 has flexible and diverse working modes. It can let the main motor rest when the wind is small, and can stabilize the input speed of the main motor as an electric motor at medium wind speed. At high wind speed, it can be used as a generator, which can not only stabilize the input speed of the main motor, but also reduce the burden on the main motor. In addition, the variable frequency motor 132 can be used as a single-blade 21 turning motor, which effectively reduces the tooling cost and installation cost.

[0092] In specific use, the speed regulating stage gear ring 122 is connected to the synchronous generator 131 through a coaxial shaft as an output; the speed regulating stage sun gear 123 is connected to the variable frequency motor 132 through a hollow shaft. Due to the use of the variable frequency motor 132 and the speed regulating gear box 12, a stable speed can be output to the synchronous generator 131. The generator also uses a high-voltage motor, so the generated electric energy can be directly connected to the power grid, or a low-voltage or medium-voltage generator can be used and connected to the power grid through the transformer 7.

[0093] In specific use, after the power from the wheel hub 22 is transmitted to the main input shaft 114, part of it is transmitted to the quasi-planetary ring gear 1121, and part of it is transmitted to the differential planetary ring gear 1112; the power transmitted to the quasi-planetary ring gear 1121 is transmitted to the differential planetary ring gear 1113 through the quasi-planetary sun gear 1122 after the quasi-planetary 112 gear transmission speed increases and reduces the torque; the power of the differential planetary carrier 1112 and the power of the differential planetary ring gear 1113 are combined and output to the ordinary planetary planetary gear 1131 through the differential planetary sun gear 1114. Since the ordinary planetary planetary gear 1131 and the ordinary planetary sun gear 1132 are connected to each other, and the ordinary planetary sun gear 1132 and the ordinary planetary planetary gear 1131 are transmitted to the speed regulating stage planetary gear 121 through the ordinary planetary sun gear 1132. The speed regulating stage planetary gear 121 is connected to the speed regulating stage ring gear 122, and the speed regulating stage ring gear 122 is connected to the synchronous generator 131. In addition, the speed regulating stage sun gear 123 is connected to the speed regulating stage planetary gear 121 , and the speed regulating stage sun gear 123 is connected to the variable frequency motor 132 .

[0094] The synchronous generator 131 is closer to the main gearbox 11 than the variable frequency motor 132 , which improves the compactness of the structure of the wind turbine generator set 100 and reduces the cost of the main gearbox 11 .

[0095] The generator set 13 also includes a synchronous generator braking system 133 and a variable frequency motor braking system 134, which are used to assist the blade pitch pneumatic braking system in braking and control the shutdown of the wind turbine generator set.

[0096] In specific use, when the wind speed is low, the synchronous generator brake system 133 is locked, and the variable frequency motor 132 is used as a generator. At this time, the variable frequency motor 132 drives the speed regulating stage sun gear 123 to rotate, and transfers its rotation to the speed regulating stage planetary gear 121, and transmits it to the speed regulating stage ring gear 122 through the speed regulating stage planetary gear 121. That is, the power transmitted from the ordinary planetary stage sun gear 1132 and the power transmitted from the speed regulating stage sun gear 123 by the variable frequency motor 132 are combined at the speed regulating stage planetary gear 121, thereby ensuring the input speed stability of the synchronous generator 131; when the energy captured by the wind wheel 2 exceeds the capacity of the variable frequency motor 132, the variable frequency motor brake system 134 is released, and the variable frequency motor 132 is used as a motor to ensure the input speed stability of the synchronous generator 131, and the synchronous generator 131 starts to work; when the speed of the wind wheel 2 reaches a certain time, the variable frequency motor 132 is used as a generator, and generates electricity simultaneously with the synchronous generator 131.

[0097] The transmission chain 1 described above is used to make its hoisting method flexible. The transmission chain 1 can be assembled together with the nacelle in the workshop and the hub 22 can be installed at the wind farm. It can also be assembled with the hub 22 and then inserted into the nacelle as a whole after arriving at the wind farm. The transmission chain 1 can also be directly transported to the wind farm and assembled on site with the nacelle and the hub 22.

[0098] like Figure 2 As shown, this embodiment also provides a wind turbine generator set 100, which includes a transmission chain 1. With the above structure, the transmission chain 1 is applied to the wind turbine generator set 100, thereby improving the compactness of the structure of the wind turbine generator set 100 and reducing the overall cost of the wind turbine generator set 100.

[0099] The wind turbine generator set 100 further includes a wind rotor 2, and the wind rotor 2 and the main input shaft 114 are both connected to the outer ring of the main bearing 115. With the above structure, the wind drives the wind rotor 2 to rotate, and the rotation of the wind rotor 2 can be transmitted to the main input shaft 114 through the main bearing 115.

[0100] The wind turbine generator set 100 further includes a main frame 3 , and the quasi-planetary stage 112 includes a quasi-planetary stage planetary frame 1123 . The main frame 3 is connected to the quasi-planetary stage planetary frame 1123 and the inner ring of the main bearing 115 .

[0101] The differential planetary stage 111 is arranged in the rear cavity of the wind rotor 2, the quasi-planetary stage 112 is arranged in the inner ring cavity of the main bearing 115, and the ordinary planetary stage 113 is arranged in the front cavity of the main frame 3. The above-mentioned structural form reduces the volume occupied by the wind turbine generator set 100, effectively utilizes the relevant space, shortens the length of the nacelle, and reduces the cost of the wind turbine generator set 100. At the same time, the main frame 3 of the wind turbine generator set 100, the flange of the quasi-planetary stage planetary frame 1123, and the inner ring of the main bearing 115 are fixed together, shortening the distance between the center of the wind rotor 2 and the center of the tower, and reducing the bending moment generated by the weight of the wind rotor 2 on the tower.

[0102] During specific use, the wind wheel 2 includes blades 21 and a hub 22 , and the accommodating cavity of the wind turbine is located in the rear cavity of the hub 22 .

[0103] The wind turbine generator set 100 further includes a rotor locking device 5 and a matching rotor locking plate 4 . The rotor locking plate 4 is arranged at the rear end of the outer ring of the main bearing 115 , and the rotor locking device 5 is arranged on the main frame 3 .

[0104] The main input shaft 114 of the main gearbox 11 is fixed as a whole with the outer ring of the main bearing 115, the wind wheel locking plate 4, and the wind wheel 2 through bolt connection. The inner ring of the main bearing 115 is fixed as a whole with the quasi-planetary planetary frame 1123 and the main frame 3 through bolt connection. The wind wheel 2 and the main frame 3 are divided into two parts, the rotating part and the fixed part, through the main bearing 115.

[0105] The load, thrust and bending moment from the wind rotor 2 are transmitted to the main frame 3 through the tapered rollers of the double-row tapered bearings; the main input shaft 114 is also connected to the quasi-planetary ring gear 1121 and the differential planetary planet carrier 1112, and the torque is transmitted to the quasi-planetary ring gear 1121 and the differential planetary planet carrier 1112 through the main input shaft 114, so as to realize power splitting. Since only the outer ring of the double-row tapered bearing and the flange of related components are arranged between the wind rotor 2 and the main frame 3, the distance from the center of the wind rotor 2 to the center of the tower is effectively shortened, and the bending moment caused by the weight of the wind rotor 2 on the tower is effectively reduced.

[0106] This embodiment further provides a power generation method for a wind turbine, which utilizes a transmission chain and / or the wind turbine. The power generation method includes: the energy captured by the wind wheel 2 is transmitted through the transmission chain 1; when the power of the energy captured by the wind wheel 2 is lower than the first critical power, the variable-frequency motor 132 acts as a generator and generates electricity by the variable-frequency motor 132; when the power of the energy captured by the wind wheel 2 is higher than the first critical power and lower than the second critical power, the variable-frequency motor 132 acts as an electric speed regulator, and the synchronous generator 131 generates electricity. The variable-frequency motor 132 is used to adjust the input speed of the synchronous generator 131; when the power of the energy captured by the wind wheel 2 is higher than the second critical power, the variable-frequency motor 132 acts as a power generation speed regulator, and the variable-frequency motor 132 and the synchronous generator 131 generate electricity simultaneously. Specifically, the power transmitted from the ordinary planetary sun gear 1132 and the power transmitted by the variable-frequency motor 132 from the speed regulation stage sun gear 123 converge at the speed regulation stage planet gear 121, thereby ensuring the stability of the input speed of the synchronous generator 131; the variable-frequency speed regulation motor 132 drives the speed regulation stage sun gear 123 to input power to the speed regulation stage planet gear 121; when the energy captured by the wind wheel 2 exceeds the capacity of the variable-frequency motor 132, the synchronous generator brake system 133 is released, and the variable-frequency motor 132 acts as an electric speed regulator to ensure the stability of the input speed of the synchronous generator 131, and the synchronous generator 131 starts to work; when the speed of the wind wheel 2 reaches a certain level, the variable-frequency motor 132 acts as a power generation speed regulator and generates electricity simultaneously with the synchronous generator 131. With the above structural form, the working mode of the variable-frequency motor 132 is flexible and diverse. In low wind conditions, the main motor can rest. In medium wind speeds, as a motor, it can make the input speed of the main motor stable. In high wind speeds, as a generator, it can not only make the input speed of the main motor stable, but also reduce the burden on the main motor.

[0107] In specific use, the first critical power and the second critical power are divided according to the speed of the wind wheel 2. The speed of the wind wheel 2 at the first critical power is smaller than the speed of the wind wheel 2 at the second power. In other embodiments, other forms can also be used to make the power of the energy captured by the wind wheel 2, and no limitation is made here.

[0108] When the power of the energy captured by the wind wheel 2 is lower than the first critical power, the synchronous generator brake system 133 is locked. With the above structural form, by locking the synchronous generator system 133, when the power of the energy captured by the wind wheel 2 is low, the synchronous generator 131 does not need to work, reducing the burden on the synchronous generator 131.

[0109] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A transmission chain, comprising a main gearbox, a speed regulating gearbox and a motor group; the main gearbox comprises a main input shaft, a main bearing, a differential planetary stage, a quasi-planetary stage and a main output shaft; the speed regulating gearbox adopts a differential planetary gear transmission; the motor group comprises a synchronous generator and a variable frequency motor, It is characterized in that The main input shaft is connected to the quasi-planetary stage and the differential planetary stage at the same time, the quasi-planetary stage outputs to the differential planetary stage, the differential planetary stage is connected to the main output shaft, the main output shaft is connected to the speed regulating gearbox, and the speed regulating gearbox is connected to the synchronous generator and the variable frequency motor at the same time; The transmission chain also includes a common planetary stage, which includes a common planetary stage sun gear, a common planetary stage planet carrier, a common planetary stage planetary gear and a common planetary stage ring gear, wherein the common planetary stage planet carrier is connected to the differential planetary stage sun gear of the differential planetary stage, and the common planetary stage sun gear is connected to the speed regulating gear box; The speed regulating gearbox comprises a speed regulating stage sun gear, a speed regulating stage planet carrier, a speed regulating stage planet gear and a speed regulating stage ring gear; the speed regulating stage planet carrier is connected to the ordinary planetary stage sun gear; the speed regulating stage ring gear is connected to the synchronous generator; the speed regulating stage sun gear is connected to the variable frequency motor, and the variable frequency motor is used to switch the working mode according to the change of the wind wheel speed; Wherein, the differential planetary stage is arranged at the front end of the main bearing.

2. The transmission chain according to claim 1, It is characterized in that The differential planetary stage comprises a differential planetary stage sun gear, a differential planetary stage planet carrier, a differential planetary stage planetary gear and a differential planetary stage ring gear. The differential planetary stage planet carrier is connected to the main input shaft, and the differential planetary stage ring gear is connected to the quasi-planetary stage.

3. The transmission chain according to claim 2, It is characterized in that The quasi-planetary stage comprises a quasi-planetary stage sun gear, a quasi-planetary stage planet carrier, a quasi-planetary stage planetary gear and a quasi-planetary stage ring gear. The quasi-planetary stage ring gear is connected to the main input shaft, and the quasi-planetary stage sun gear is connected to the differential planetary stage ring gear.

4. The transmission chain according to claim 3, It is characterized in that The differential planetary stage planetary gear is fixed to the differential planetary stage planetary carrier via a flexible pin; And / or, the quasi-planetary planetary gear is fixed to the quasi-planetary planetary carrier via a flexible pin.

5. The transmission chain according to claim 3, It is characterized in that The quasi-planetary sun gear is connected to the differential planetary ring gear via a conical disk; and / or, the quasi-planetary sun gear and the differential planetary ring gear are integral floating parts.

6. The transmission chain according to claim 3, It is characterized in that The outer ring of the main bearing is connected to the main input shaft, and the inner ring of the main bearing is connected to the quasi-planetary planet carrier.

7. The transmission chain according to claim 6, It is characterized in that The main bearing is a double-row tapered bearing.

8. The transmission chain according to claim 1, It is characterized in that The motor group also includes a synchronous generator braking system and a speed regulating motor braking system.

9. A wind turbine generator set, It is characterized in that The wind turbine generator set comprises the transmission chain according to any one of claims 1-8.

10. The wind turbine generator set according to claim 9, It is characterized in that The wind turbine generator set further comprises a wind wheel, wherein the wind wheel and the main input shaft are both connected to the outer ring of the main bearing; And / or, the wind turbine generator set further includes a main frame, the quasi-planetary stage includes a quasi-planetary stage planetary frame, and the main frame is connected to the quasi-planetary stage planetary frame and the inner ring of the main bearing.

11. The wind turbine generator set according to claim 10, It is characterized in that The wind turbine generator set further comprises a wind rotor locking device and a matching wind rotor locking plate, wherein the wind rotor locking device is arranged on the main frame, and the wind rotor locking plate is connected to the outer ring of the main bearing.

12. A method for generating electricity from a wind turbine generator set, using a transmission chain as claimed in any one of claims 1 to 8, and / or a wind turbine generator set as claimed in any one of claims 9 to 11, It is characterized in that The power generation method comprises: The energy captured by the wind wheel is transmitted through the transmission chain; When the power of energy captured by the wind wheel is lower than the first critical power, the variable frequency motor is used as a generator to generate electricity; When the power of the energy captured by the wind wheel is higher than the first critical power and lower than the second critical power, the variable frequency motor acts as an electric speed regulator, and the synchronous generator generates electricity. The variable frequency motor is used to adjust the input speed of the synchronous generator. When the power of energy captured by the wind wheel is higher than the second critical power, the variable frequency motor is used as a generator speed regulator, and the variable frequency motor and the synchronous generator generate electricity simultaneously.

13. The method for generating electricity according to claim 12, It is characterized in that When the power of energy captured by the wind wheel is lower than a first critical power, the synchronous generator brake system is locked.

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