CN117005985A

CN117005985A - Pitch driving system, wind generating set and pitch control method

Info

Publication number: CN117005985A
Application number: CN202210452476.3A
Authority: CN
Inventors: 章钟伟; 张竹; 程伟
Original assignee: Beijing Goldwind Science and Creation Windpower Equipment Co Ltd
Current assignee: Beijing Goldwind Science and Creation Windpower Equipment Co Ltd
Priority date: 2022-04-27
Filing date: 2022-04-27
Publication date: 2023-11-07

Abstract

The application relates to a pitch drive system, a wind generating set and a pitch control method. The energy station is used for containing fluid and can provide power for fluid operation. The first driving module comprises a first inlet pipe and a first outlet pipe which are arranged in pairs, and the first inlet pipe and the first outlet pipe are connected between the energy station and the variable pitch telescopic cylinder. The second driving module comprises a second inlet pipe and a second outlet pipe which are arranged in pairs, and the second inlet pipe and the second outlet pipe are both connected between the energy station and the locking telescopic cylinder. The control valve group is arranged on the first driving module and the second driving module to control the connection or disconnection of at least one of the first driving module and the second driving module and the energy station. The embodiment of the application can realize the variable pitch function under different working conditions and ensure the reliability.

Description

Pitch driving system, wind generating set and pitch control method

Technical Field

The application relates to the technical field of wind power generation, in particular to a variable pitch drive system, a wind generating set and a variable pitch control method.

Background

Along with the rapid development of the technical route of the wind generating set, the capacity of the wind generating set is continuously increased, and the length of the blades of the wind generating set is also longer and longer. At present, the length of the blade of the offshore unit is over 90 meters, the weight is over 38 tons, and the blade of the offshore unit is more and more difficult to pitch.

Moreover, the blades not only need to be pitched in service, but also need to be pitched in the assembly process or the hoisting process of the blades, namely, the pitch-variable telescopic cylinders and the locking telescopic cylinders need to be controlled to perform telescopic operation so as to realize pitch-variable and locking of the blades. However, in the process of assembling a unit or hoisting blades, the unit cannot supply power or a pitch system has safety risks and the like, so that the pitch operation is difficult and a certain risk exists.

Accordingly, there is a need for a pitch drive system.

Disclosure of Invention

The embodiment of the application provides a variable pitch driving system, a wind generating set and a variable pitch control method.

In one aspect, according to an embodiment of the present application, there is provided a pitch drive system for driving a pitch telescopic cylinder and a locking telescopic cylinder, the pitch drive system including: the energy station is used for containing fluid and can provide power for fluid operation; the first driving module comprises a first inlet pipe and a first outlet pipe which are arranged in pairs, wherein the first inlet pipe and the first outlet pipe are connected between the energy station and the variable pitch telescopic cylinder, the first inlet pipe guides fluid of the energy station to one of a first rod cavity and a first rodless cavity of the variable pitch telescopic cylinder, and the first outlet pipe guides fluid of the other one of the first rod cavity and the first rodless cavity to the energy station; the second driving module comprises a second inlet pipe and a second outlet pipe which are arranged in pairs, the second inlet pipe and the second outlet pipe are connected between the energy station and the locking telescopic cylinder, the second inlet pipe guides fluid of the energy station to one of a second rod cavity and a second rodless cavity of the locking telescopic cylinder, and the second outlet pipe guides fluid of the other one of the second rod cavity and the second rodless cavity to the energy station; the control valve group is arranged on the first driving module and the second driving module, and the control valve group can control the connection or disconnection of at least one of the first driving module and the second driving module and the energy station.

According to one aspect of the embodiment of the application, the control valve group comprises a first valve and a second valve, the first valve is arranged on the first inlet pipe, and the first valve can control the connection or disconnection of the first inlet pipe; the second valve is arranged on the second outlet pipe, and the second valve can control the connection or disconnection of the second outlet pipe.

According to an aspect of the embodiment of the application, the second driving module comprises a locking reversing valve, the locking reversing valve is arranged between the locking telescopic cylinder and the second valve, the second inlet pipe and the second outlet pipe are both connected with the locking reversing valve, and the locking reversing valve can be switched between a first state and a second state; in the first state, the second inlet pipe is communicated with the second rod cavity, and the second outlet pipe is communicated with the second rodless cavity; in the second state, the second inlet pipe is communicated with the second rodless cavity, and the second outlet pipe is communicated with the second rod cavity.

According to an aspect of the embodiment of the present application, the control valve group further includes a third valve disposed on the second inlet pipe, and the second driving module further includes an accumulator connected to the second inlet pipe and located downstream of the third valve; the third valve is a one-way valve and is communicated in one way from the energy station to the locking telescopic cylinder.

According to an aspect of the embodiment of the application, the first driving module further comprises a pitch reversing valve, the pitch reversing valve is arranged between the pitch telescopic cylinder and the first valve, the first inlet pipe and the first outlet pipe are both connected with the pitch reversing valve, and the pitch reversing valve can be switched between a third state and a fourth state; in a third state, the first inlet pipe is communicated with the first rod cavity, and the first outlet pipe is communicated with the first rodless cavity; in the fourth state, the first inlet pipe is communicated with the first rodless cavity, and the first outlet pipe is communicated with the first rod cavity.

According to an aspect of the embodiment of the present application, the first driving module further includes a bidirectional balance valve, the bidirectional balance valve is disposed between the pitch telescopic cylinder and the pitch reversing valve, and the first inlet pipe and the first outlet pipe are connected to the bidirectional balance valve.

According to an aspect of the embodiment of the application, the pitch drive system further comprises a quick connector, and a port of at least one of the first inlet pipe, the first outlet pipe, the second inlet pipe and the second outlet pipe facing away from the energy station is connected with the quick connector.

According to one aspect of an embodiment of the present application, an energy station includes a fluid inlet pipe and a fluid outlet pipe, the fluid inlet pipe is connected to a first inlet pipe and a second inlet pipe, and the fluid outlet pipe is connected to the first outlet pipe and the second outlet pipe; a first overflow valve is connected between the fluid outlet pipe and the fluid inlet pipe.

According to an aspect of the embodiment of the present application, the first driving module further includes a first pressure relief branch and a second pressure relief branch, one end of the first pressure relief branch is communicated with the first inlet pipe and the other end is communicated with the fluid outlet pipe, and one end of the second pressure relief branch is communicated with the first outlet pipe and the other end is communicated with the fluid outlet pipe; the control valve group further comprises a fourth valve and a fifth valve, the fourth valve is arranged on the first pressure relief branch and used for controlling the on-off of the first pressure relief branch, and the fifth valve is arranged on the second pressure relief branch and used for controlling the on-off of the second pressure relief branch.

According to an aspect of the embodiment of the present application, the second driving module further includes a third pressure relief branch, one end of the third pressure relief branch is connected to the second inlet pipe, and the other end is connected to the second outlet pipe; the control valve group further comprises a sixth valve, and the sixth valve is arranged on the third pressure relief branch and used for controlling the on-off of the third pressure relief branch.

In another aspect, according to an embodiment of the present application, there is provided a wind turbine generator set including: an impeller comprising a hub and blades; the pitch system comprises a pitch bearing, a pitch telescopic cylinder and a locking telescopic cylinder, wherein one of an inner ring and an outer ring of the pitch bearing is connected with the hub, the other is connected with the blade, the pitch telescopic cylinder is used for driving the inner ring and the outer ring to rotate relatively, and the locking telescopic cylinder is used for locking the relative arrangement of the blade and the hub; as described above, the first inlet pipe is connected to one of the first rod-shaped chamber and the first rodless chamber of the pitch-controlled telescopic cylinder, the first outlet pipe is connected to the other of the first rod-shaped chamber and the first rodless chamber of the pitch-controlled telescopic cylinder, the second inlet pipe is connected to one of the second rod-shaped chamber and the second rodless chamber of the locking telescopic cylinder, and the second outlet pipe is connected to the other of the second rod-shaped chamber and the second rodless chamber.

In still another aspect, an embodiment of the present application provides a method for performing pitch control by using the pitch drive system, including: connecting the first inlet pipe with one of a first rod cavity and a first rodless cavity of the pitch telescoping cylinder, connecting the first outlet pipe with the other of the first rod cavity and the first rodless cavity, simultaneously connecting the second inlet pipe with one of a second rod cavity and a second rodless cavity of the locking telescoping cylinder, and connecting the second outlet pipe with the other of the second rod cavity and the second rodless cavity; disconnecting the first driving module from the energy station through the control valve group; driving fluid in the energy station to enter a second rod cavity of the locking telescopic cylinder, so that the locking telescopic cylinder contracts, and the blades are unlocked from the hub; the first driving module is communicated with the energy station through the control valve group; and driving fluid in the energy station to enter a first rod cavity or a first rodless cavity of the variable pitch telescopic cylinder, so that the blade rotates relative to the hub, and the variable pitch of the blade is realized.

According to the pitch control system, the wind generating set and the pitch control method provided by the embodiment of the application, the energy station is used for containing fluid and driving the fluid to enter the first driving module and the second driving module, the first inlet pipe and the first outlet pipe are arranged between the energy station and the first driving module in pairs, the second inlet pipe and the second outlet pipe are arranged between the energy station and the second driving module in pairs, and the fluid can enter the first driving module and the second driving module respectively through the first inlet pipe and the second inlet pipe so as to control the pitch telescopic cylinder and the locking telescopic cylinder to stretch, so that the pitch requirement and the locking requirement after pitch are met. Through set up the control valves on first drive module and second drive module, can control the control valves according to the demand, control first drive module and second drive module and the communication time sequence at energy resource station, for example can control first drive module and energy resource station intercommunication and first drive module and energy resource station disconnection realize the unblock of becoming the flexible jar of oar earlier, then control first drive module and energy resource station intercommunication and realize becoming the oar, guarantee to become the unblock before oar requirement and become locking requirement after the oar etc. improve the reliability of becoming oar actuating system.

Drawings

Features, advantages, and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic view of a wind turbine generator system according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a pitch drive system according to an embodiment of the present application;

FIG. 3 is a schematic view of a pitch drive system according to another embodiment of the present application;

FIG. 4 is a schematic view of a partial structure of a pitch drive system according to an embodiment of the application;

fig. 5 is a flow chart of a method for performing pitch control by a pitch drive system according to an embodiment of the present application.

Wherein:

1-an energy station; 1 a-fluid inlet tube; 1 b-fluid outlet tube; 11-a first overflow valve; 12-carrying out the box; 13-driving a pump;

2-a first drive module; 2 a-a first inlet pipe; 2 b-a first outlet pipe; 21-a pitch reversing valve; 22-a two-way balancing valve; 221-a first balancing valve; 222-a second balancing valve; 2 c-a first pressure relief branch; 2 d-a second pressure relief branch;

3-a second drive module; 3 a-a second inlet pipe; 3 b-a second exit tube; 31-locking a reversing valve; a 32-accumulator; 3 c-a third pressure relief branch;

41-a first valve; 42-a second valve; 43-third valve; 43 a-one-way valve; 44-fourth valve; 45-fifth valve; 46-sixth valve;

5-quick connector; s1-a first state; s2-a second state; s3-a third state; s4-a fourth state;

100-a variable pitch telescopic cylinder; 101-a first rod-bearing cavity; 102-a first rodless cavity; 103-a first drive rod; 104-a first piston;

200-locking a telescopic cylinder; 201-a second rod-bearing cavity; 202-a second rodless cavity; 203-a second drive rod; 204-a second piston.

300-tower; 400-nacelle; 410-a generator; 500-impeller; 510-hub; 520-blade.

Detailed Description

Features and exemplary embodiments of various aspects of the application are described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the application. It will be apparent, however, to one skilled in the art that the present application may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the application by showing examples of the application. In the drawings and the following description, at least some well-known structures and techniques have not been shown in detail in order not to unnecessarily obscure the present application; also, the dimensions of some of the structures may be exaggerated for clarity. Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

The azimuth terms appearing in the following description are all directions shown in the drawings, and are not limiting on the pitch drive system, the wind turbine generator set and the pitch control method of the present application. In the description of the present application, it should also be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be directly connected or indirectly connected. The specific meaning of the above terms in the present application can be understood as appropriate by those of ordinary skill in the art.

For a better understanding of the present application, a pitch drive system, a wind turbine generator set and a pitch control method according to embodiments of the application are described in detail below in connection with fig. 1 to 5.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a wind turbine generator system according to an embodiment of the present application, where the wind turbine generator system includes an impeller 500, a pitch system and a pitch driving system, and of course, the wind turbine generator system further includes a tower 300, a nacelle 400 and a generator 410. The tower 300 is connected to a wind turbine foundation, the nacelle 400 is disposed on top of the tower 300, and the generator 410 is disposed on the nacelle 400. In some examples, the generator 410 may be located outside of the nacelle 400, although in some examples, the generator 410 may be located inside of the nacelle 400. The impeller 500 includes a hub 510 and a plurality of blades 520 connected to the hub 510, wherein the impeller 500 is connected to the rotation shaft of the generator 410 through the hub 510, and when wind acts on the blades 520, the rotation shafts of the whole impeller 500 and the generator 410 are driven to rotate, so as to convert wind energy into electric energy.

The pitch system is arranged in the hub 510 and comprises a pitch bearing, a pitch telescopic cylinder 100 and a locking telescopic cylinder 200, one of an inner ring and an outer ring of the pitch bearing is connected with the hub 510, the other is connected with the blade 520, the pitch telescopic cylinder 100 is used for driving the inner ring and the outer ring to rotate relatively, the locking telescopic cylinder 200 is used for locking the relative arrangement of the blade 520 and the hub 510, and pitch operation of the blade 520 in service is realized through the pitch system.

Along with the rapid development of the technical route of the wind generating set, the requirements on the wind generating set are higher and higher, in order to improve the efficiency, the blade 520 needs to be pitched not only in service, but also in the process of assembling the set or hoisting the blade 520. However, during assembly of the unit or hoisting of the blade 520, the unit cannot supply power or the pitch system itself has safety risks, which results in difficult pitch operation and a certain risk.

Based on the above-mentioned drawbacks, the embodiment of the present application provides a pitch drive system, which may be produced and sold separately as an independent product, or may, of course, be used with and as part of a wind turbine. When used in a wind turbine, the pitch drive system may be used in conjunction with pitch cylinder 100 and lock cylinder 200 of the wind turbine.

Referring to fig. 2 and 3, fig. 2 is a schematic structural diagram of a pitch drive system according to an embodiment of the application, and fig. 3 is a schematic structural diagram of a pitch drive system according to another embodiment of the application. The embodiment of the application provides a pitch drive system for driving a pitch telescopic cylinder 100 and a locking telescopic cylinder 200, which comprises an energy station 1, a first drive module 2, a second drive module 3 and a control valve group.

The energy station 1 is used for containing fluid and is capable of providing power for fluid operation. Alternatively, the fluid may be in a liquid state, a gaseous state, or a mixture of both in the pitch drive system. Alternatively, the energy station 1 may comprise a carrying case 12 for containing the fluid, and the energy station 1 may further comprise a drive pump 13 or other power element to connect with the carrying case 12 and provide operational power to the fluid such that the fluid circulates in the pitch drive system.

The pitch drive system provided by the application can be used for driving the pitch telescopic cylinder 100 and the locking telescopic cylinder 200, wherein the pitch telescopic cylinder 100 is used for enabling the blades 520 to perform pitch operation, and the pitch telescopic cylinder 100 can comprise a plurality of pitch telescopic cylinders 100 so as to enable a plurality of blades 520 to perform pitch operation. It will be appreciated that each pitch cylinder 100 may also be comprised of at least two pitch cylinders 100, with at least two pitch cylinders 100 acting together on one blade 520.

Illustratively, as shown in fig. 2, two pitch cylinders 100, each pitch cylinder 100 having a first rod cavity 101 and a first rodless cavity 102. Optionally, a first driving rod 103 is disposed in the first rod cavity 101, and the first driving rod 103 may be disposed on a piston rod in the pitch telescopic cylinder 100, where the first driving rod 103 may be directly connected to a first piston 104, and the first piston 104 separates the first rod cavity 101 from the first rodless cavity 102.

Illustratively, when it is desired to retract the first drive rod 103 of the pitch cylinder 100, fluid may be provided to the first rod chamber 101 and fluid may be released from the first rod chamber 102, and when it is desired to extend the first drive rod 103 of the pitch cylinder 100, fluid may be provided to the first rod chamber 102 and fluid may be released from the first rod chamber 101.

The locking telescopic cylinder 200 is used for locking or unlocking the movement of the blade 520, wherein the locking telescopic cylinder 200 has a second rod-shaped cavity 201 and a second rod-free cavity 202. Alternatively, the second rod chamber 201 is provided with a second driving rod 203, and the second driving rod 203 may be disposed on a piston rod in the locking telescopic cylinder 200, however, the second driving rod 203 may also be directly connected to the second piston 204, and the second piston 204 separates the second rod chamber 201 from the second rodless chamber 202.

Optionally, an elastic member is further provided in the locking telescopic cylinder 200, and the elastic member may be provided between the inner wall of the second rodless chamber 202 and the second piston 204, and of course, the elastic member may be provided in the second rod chamber 201.

Illustratively, when the resilient member is disposed within second rod cavity 201, second rodless cavity 202 may be caused to release fluid when it is desired to retract second drive rod 203 of locking telescoping cylinder 200, and second rod cavity 201 may be provided with fluid when it is desired to extend second drive rod 203 of pitch telescoping cylinder 100.

The first driving module 2 includes a first inlet pipe 2a and a first outlet pipe 2b arranged in pairs, the first inlet pipe 2a and the first outlet pipe 2b are both connected between the energy station 1 and the pitch telescopic cylinder 100, the first inlet pipe 2a guides fluid of the energy station 1 to one of the first rod chamber 101 and the first rodless chamber 102 of the pitch telescopic cylinder 100, and the first outlet pipe 2b guides fluid of the other one of the first rod chamber 101 and the first rodless chamber 102 to the energy station 1.

Illustratively, the first inlet tube 2a communicates with the first rod chamber 101 such that fluid in the carrying case 12 of the energy station 1 is directed into the first rod chamber 101 through the first inlet tube 2a under the drive of the drive pump 13, and the first outlet tube 2b communicates with the first rodless chamber 102 such that fluid in the first rodless chamber 102 is released back into the carrying case 12 of the energy station 1 through the first outlet tube 2 b. Through the above arrangement, the first rod cavity 101 is provided with stable fluid by the energy station 1, and the first rodless cavity 102 releases the fluid, so that the first driving module 2 performs the pitch operation, the pitch function of the pitch driving system is realized, and the blades 520 are controlled to perform the pitch operation.

The second driving module 3 includes a second inlet pipe 3a and a second outlet pipe 3b provided in pairs, the second inlet pipe 3a and the second outlet pipe 3b are connected between the energy station 1 and the locking telescopic cylinder 200, the second inlet pipe 3a guides fluid of the energy station 1 to one of the second rod-shaped chamber 201 and the second rodless chamber 202 of the locking telescopic cylinder 200, and the second outlet pipe 3b guides fluid of the other of the second rod-shaped chamber 201 and the second rodless chamber 202 to the energy station 1.

Illustratively, the second inlet tube 3a communicates with the second rod-shaped cavity 201 such that fluid in the carrying case 12 in the energy station 1 is directed into the second rod-shaped cavity 201 through the second inlet tube 3a under the drive of the drive pump 13, and the second outlet tube 3b communicates with the second rodless cavity 202 such that fluid in the second rodless cavity 202 is released back into the carrying case 12 in the energy station 1 through the second outlet tube 3 b. With the above arrangement, it is possible to make the locking telescopic cylinder 200 have a stable fluid therein, that is, the energy station 1 supplies the fluid to the second rod chamber 201, and the second rodless chamber 202 releases the fluid, ensuring a stable operation of the pitch telescopic cylinder 100, causing the second driving rod 203 to retract, thereby causing the second driving module 3 to perform an unlocking operation to unlock the blade 520 so as to be movable.

The control valve group is arranged on the first driving module 2 and the second driving module 3, and the control valve group can control the connection or disconnection of at least one of the first driving module 2 and the second driving module 3 and the energy station 1.

Optionally, the control valve group controls the connection or disconnection of the first driving module 2 and the energy station 1, so as to control the first driving module 2 to switch on the pitch driving function or switch off the pitch driving function.

Optionally, the control valve group controls the connection or disconnection of the second driving module 3 and the energy station 1, so as to control the second driving module 3 to open the pitch unlocking function or close the pitch unlocking function.

And, by controlling the order in which the control valve groups on the first driving module 2 and the second driving module 3 are opened or closed, for example, the control valve group on the second driving module 3 is opened first to make the locking telescopic cylinder 200 have a stable fluid, so that the second driving module 3 performs an unlocking operation to unlock the vane 520 to enable movement thereof. Then, the control valve group on the first driving module 2 is opened again to enable the pitch telescopic cylinder 100 to have stable fluid, so that the first driving module 2 executes pitch operation, the pitch function of the pitch driving system is realized, and the blades 520 are controlled to perform pitch operation. Through this setting, can make become oar actuating system and realize becoming oar function, can also improve security, reliability.

With continued reference to fig. 2, in some alternative embodiments, the control valve set includes a first valve 41 and a second valve 42, where the first valve 41 is disposed on the first inlet pipe 2a, and the first valve 41 can control the connection or disconnection of the first inlet pipe 2 a. The second valve 42 is provided in the second outlet pipe 3b, and the second valve 42 can control the connection and disconnection of the second outlet pipe 3 b.

Through set up first valve 41 and second valve 42 respectively at first advance pipe 2a and second exit tube 3b, can the individual control first drive module 2 and the second drive module 3 with the intercommunication or disconnection of energy station 1 to make the fluid of energy station 1 get into respectively and become flexible jar 100 and locking flexible jar 200, make the fluid that becomes flexible jar 100 and locking flexible jar 200 can not influence each other, improve the reliability of becoming oar actuating system.

In some alternative embodiments, the second drive module 3 comprises a locking reversing valve 31, the locking reversing valve 31 being arranged between the locking telescopic cylinder 200 and the second valve 42, the second inlet pipe 3a and the second outlet pipe 3b being connected to the locking reversing valve 31, the locking reversing valve 31 being switchable between a first state S1 and a second state S2.

Alternatively, the lock direction valve 31 is disposed between the lock expansion cylinder 200 and the second valve 42, and the second valve 42 is opened, and fluid enters the lock expansion cylinder 200 through the lock direction valve 31, thereby controlling locking or unlocking of the lock expansion cylinder 200.

The switching between the first state S1 and the second state S2 is enabled by the lock switching valve 31 to cause the lock expansion cylinder 200 to perform an unlocking operation or a locking operation.

In the first state S1, the second inlet pipe 3a communicates with the second rod-shaped cavity 201, and the second outlet pipe 3b communicates with the second rodless cavity 202. In this state, the fluid of the power station 1 enters the second rod-shaped chamber 201 of the locking telescopic cylinder 200 through the first inlet pipe 2a, and the second driving rod 203 is retracted to allow the fluid in the second rodless chamber 202 to enter the power station 1 through the second outlet pipe 3b, so that the locking telescopic cylinder 200 performs an unlocking operation.

In the second state S2, the second inlet pipe 3a communicates with the second rodless chamber 202, and the second outlet pipe 3b communicates with the second rod-shaped chamber 201. In this state, the fluid of the power station 1 enters the second rodless chamber 202 of the locking telescopic cylinder 200 through the second inlet pipe 3a, and the second driving rod 203 is extended to allow the fluid in the second rod chamber 201 to enter the power station 1 through the second outlet pipe 3b, thereby causing the locking telescopic cylinder 200 to perform the locking operation.

Alternatively, the lock selector valve 31 may employ a solenoid valve, a manual valve, or the like.

In the working process of the pitch drive system, abnormal phenomena such as fluid leakage, faults and the like may occur, so that no stable fluid enters the locking telescopic cylinder 200, and the risk of automatic locking, alarming or stopping of the locking telescopic cylinder 200 is caused, the normal operation of the pitch drive system is affected, and the problem of potential safety hazard exists.

In response to the above drawbacks, in some alternative embodiments, the control valve group further comprises a third valve 43 provided to the second inlet pipe 3a, the second drive module 3 further comprising an accumulator 32, the accumulator 32 being connected to the second inlet pipe 3a and downstream of the third valve 43.

The accumulator 32 may pre-store a certain amount of fluid to compensate for leakage of the certain amount of fluid. By providing the accumulator 32 in the second inlet pipe 3a, when the fluid entering the locking telescopic cylinder 200 is insufficient to control the locking telescopic cylinder to perform unlocking operation, the fluid in the accumulator 32 can enter the locking telescopic cylinder 200 as compensation, so that stable fluid enters the locking telescopic cylinder 200, stable operation of the locking telescopic cylinder 200 is ensured, and reliability of the pitch drive system is improved.

Optionally, the third valve 43 is a one-way valve 43a and is turned on in one direction from the power station 1 to the locking telescopic cylinder 200. The third valve 43 is provided with a check valve 43a so that fluid can only enter the locking telescopic cylinder 200 in one direction, ensuring that the locking telescopic cylinder 200 always performs the unlocking operation. And, the accumulator 32 is arranged at the downstream of the check valve 43a, so that the fluid in the accumulator 32 can not flow back to the energy station 1 from the check valve 32, and the condition that the fluid can enter the locking telescopic cylinder 200 is ensured, so that the locking telescopic cylinder 200 can stably operate to keep the unlocking state all the time, the automatic locking of the locking telescopic cylinder 200 caused by the system decompression or other faults is avoided, and the safety and reliability of the pitch drive system are ensured.

In some alternative embodiments, the first driving module 2 further includes a pitch reversing valve 21, the pitch reversing valve 21 is disposed between the pitch telescopic cylinder 100 and the first valve 41, the first inlet pipe 2a and the first outlet pipe 2b are connected to the pitch reversing valve 21, and the pitch reversing valve 21 is switchable between a third state S3 and a fourth state S4.

Alternatively, the pitch reversing valve 21 may be a single manual reversing valve, although the pitch reversing valve 21 may be a single solenoid valve. The pitch reversing valve 21 may be various types of solenoid valves as long as the solenoid valve is capable of allowing fluid to enter and exit the pitch cylinder 100. Alternatively, the pitch reversing valve 21 may also be an electric reversing valve.

In the third state S3, the reversing valve 21 is controlled such that the first inlet pipe 2a communicates with the first rod-shaped cavity 101 and the first outlet pipe 2b communicates with the first rodless cavity 102. In this state, the fluid of the power station 1 enters the first rod chamber 101 of the pitch telescopic cylinder 100 through the first inlet pipe 2a, and the first driving rod 103 is retracted to allow the fluid in the first rodless chamber 102 to enter the power station 1 through the first outlet pipe 2b, so that the pitch telescopic cylinder 100 performs a pitch operation, thereby achieving the pitch of the blades 520.

In the fourth state S4, the reversing valve 21 is made so that the first inlet pipe 2a communicates with the first rodless chamber 102, and the first outlet pipe 2b communicates with the first rod-shaped chamber 101. In this state, the fluid of the power station 1 enters the first rodless chamber 102 of the pitch cylinder 100 through the first inlet pipe 2a, and the first driving rod 103 is extended to allow the fluid in the first rod chamber 101 to enter the power station 1 through the first outlet pipe 2b, so that the pitch cylinder 100 performs a pitch operation, thereby achieving feathering of the blades 520.

Alternatively, when the pitch cylinder 100 includes a plurality of pitch cylinders 100, it is only necessary that the plurality of first driving rods 103 perform the extension or retraction motions at the same time.

In some alternative embodiments, the first driving module 2 further includes a bidirectional balancing valve 22, the bidirectional balancing valve 22 is disposed between the pitch telescopic cylinder 100 and the pitch reversing valve 21, and the first inlet pipe 2a and the first outlet pipe 2b are connected to the bidirectional balancing valve 22.

Through setting up two-way balance valve 22, under the circumstances of outage, guarantee that the actuating lever of the flexible jar 100 of becoming oar can not stretch out and draw back at will or rock, guarantee that the driving system of becoming oar realizes the security and the reliability of becoming oar function, and then make blade 520 at the stable operation of becoming oar in-process. Moreover, by arranging the bidirectional balance valve 22, the variable pitch telescopic cylinder 100 can be controlled to keep at a certain variable pitch angle when the blades 520 are changed, so that the maintenance or other operations of workers are facilitated, the safety is ensured, and the universality is stronger.

Alternatively, the two-way balancing valve 22 may also be a hydraulic balancing valve.

Referring to fig. 4, fig. 4 is a schematic partial structure of a pitch drive system according to an embodiment of the present application, in some alternative embodiments, the bi-directional balance valve 22 may include a first balance valve 221 and a second balance valve 222, the first outlet A2 of the bi-directional balance valve 22 is in communication with one of the first rod chamber 101 and the first rodless chamber 102, the second outlet B2 is in communication with the other of the first rod chamber 101 and the first rodless chamber 102, and the first inlet A1 and the second inlet B1 of the bi-directional balance valve 22 may be in communication with the energy station 1, respectively. Alternatively, the first inlet A1 and the second inlet B1 of the two-way balancing valve 22 may be respectively communicated with the pitch reversing valve 21.

Alternatively, when it is desired to retract the first drive rod 103 of the pitch telescoping cylinder 100, fluid may be provided to the first rod chamber 101 by connecting the first outlet A2 of the first balancing valve 221 to the first rod chamber 101, while the second outlet B2 of the second balancing valve 222 is connected to the first rodless chamber 102 and releases the fluid in the first rodless chamber 102. When the first driving rod 103 of the pitch expansion cylinder 100 needs to be extended, the connection relationship between the first balance valve 221 and the second balance valve 222 and the first rod chamber 101 and the first rodless chamber 102 need only be changed, and will not be described herein.

With continued reference to fig. 4, the pitch reversing valve 21 may be a three-position four-way valve, the a port of the pitch reversing valve 21 may be in communication with one of the first inlet A1 and the second inlet B1 of the first balancing valve 221, the B port of the pitch reversing valve 21 may be in communication with the other of the first inlet A1 and the second inlet B1 of the second balancing valve 222, the P port of the pitch reversing valve 21 is disposed on the fluid inlet pipe 1a and in communication with the driving pump 13 of the energy station 1, and the T port of the pitch reversing valve 21 is disposed on the fluid outlet pipe 1B and in communication with the housing box 12 of the energy station 1 to control fluid flow between the energy station 1 and the pitch telescopic cylinder 100.

In order to realize the lifting of the blade 520 in the assembly process or the lifting process of the blade 520, a plurality of pipelines are needed to be connected with the variable pitch telescopic cylinder 100 and the locking telescopic cylinder 200, the pipelines are more and are connected in a complex manner, the assembly efficiency is low, and the phenomenon of fluid leakage possibly occurs due to poor connection.

In response to the above drawbacks, in some alternative embodiments, the pitch drive system further comprises a quick connector 5, and a quick connector 5 is connected to a port of at least one of the first inlet pipe 2a, the first outlet pipe 2b, the second inlet pipe 3a, and the second outlet pipe 3b facing away from the energy station 1.

For example, referring to fig. 3, the first inlet pipe 2a and the first outlet pipe 2b are respectively provided with a quick connector 5 to be connected with the first rod cavity 101 and the first rodless cavity 102 of the pitch telescopic cylinder 100, and the second inlet pipe 3a and the second outlet pipe 3b are respectively provided with a quick connector 5 to be connected with the second rod cavity 201 and the second rodless cavity 202 of the locking telescopic cylinder 200.

Optionally, the first inlet pipe 2a and the second inlet pipe 3a may also be provided with a plurality of quick connectors 5, for example, the first inlet pipe 2a and the first outlet pipe 2b are provided with quick connectors 5 to be connected with the pitch reversing valve 21, and the first inlet pipe 2a and the first outlet pipe 2b connected with the pitch reversing valve 21 are also provided with quick connectors 5 to be connected with the pitch telescopic cylinder 100.

Through setting up quick connector 5 in order to realize that first advance pipe 2a, second exit tube 3b and become the connection of oar telescopic cylinder 100 to and realize that second advance pipe 3a, second exit tube 3b and locking telescopic cylinder 200 are connected, and realize that first advance pipe 2a, first exit tube 2b and become the connection of oar switching-over valve 21, be favorable to improving on-the-spot quick installation and dismantlement, improve work efficiency, make the equipment more convenient. In addition, the quick connector 5 can reduce the leakage of fluid during assembly, and avoid the problem of environmental pollution.

In some alternative embodiments, the energy station 1 includes a fluid inlet pipe 1a and a fluid outlet pipe 1b, the fluid inlet pipe 1a being connected to the first inlet pipe 2a and the second inlet pipe 3a, and the fluid outlet pipe 1b being connected to the first outlet pipe 2b and the second outlet pipe 3b.

Fluid in the energy station 1 flows out of the fluid inlet pipe 1a and enters the first drive module 2 through the first inlet pipe 2a, and also enters the second drive module 3 through the second inlet pipe 3 a. The fluid of the first drive module 2 flows out of the first outlet pipe 2b and back to the energy station 1 through the fluid outlet pipe 1b, and the fluid of the second drive module 3 flows out of the second outlet pipe 3b and back to the energy station 1 through the fluid outlet pipe 1 b.

With continued reference to fig. 3, in some alternative embodiments, a first relief valve 11 is connected between the fluid outlet tube 1b and the fluid inlet tube 1a to regulate the maximum pressure of the pitch drive system. When the fluid flowing out of the energy station 1 from the fluid outlet pipe 1b exceeds the load of the pitch drive system, the fluid exceeding the load can flow back to the energy station 1 from the fluid outlet pipe 1b through the first overflow valve 11, so that the pressure stability of the pitch drive system is ensured, and the pitch drive system can stably operate.

Optionally, a first filter 14 may be further disposed on the fluid outlet pipe 1b to remove impurities that may be carried by the fluid entering the energy station 1, and ensure the effectiveness of the energy station 1. Alternatively, the first filter 14 may be provided downstream of the first relief valve 11. It will be appreciated that a second filter 15 may also be provided on the fluid inlet pipe 1a to remove impurities that may be carried by the fluid entering the pitch drive system, ensuring safe operation of the pitch drive system. Alternatively, the second filter 15 may be arranged upstream of the control valve group.

With continued reference to fig. 4, in order to avoid the problem that there is a safety risk of the time-varying propeller drive system when the pipeline is removed after the wind turbine assembly or the hoisting of the blades 520 is completed, in some alternative embodiments, the first drive module 2 further includes a first pressure relief branch 2c and a second pressure relief branch 2d, wherein one end of the first pressure relief branch 2c is communicated with the first inlet pipe 2a and the other end is communicated with the fluid outlet pipe 1b, and one end of the second pressure relief branch 2d is communicated with the first outlet pipe 2b and the other end is communicated with the fluid outlet pipe 1 b. The control valve group further comprises a fourth valve 44 and a fifth valve 45, the fourth valve 44 is arranged on the first pressure relief branch 2c and used for controlling the on-off of the first pressure relief branch 2c, and the fifth valve 45 is arranged on the second pressure relief branch 2d and used for controlling the on-off of the second pressure relief branch 2 d.

By controlling the fourth valve 44 to open, fluid in the pitch cylinder 100 may flow out of the first inlet pipe 2a and then into the first outlet pipe 2b from the first pressure relief branch 2c to flow back to the energy station 1, so that fluid in the pitch cylinder 100 flows back to the energy station 1. By controlling the fifth valve 45 to open, fluid in the pitch cylinder 100 can flow out of the first outlet pipe 2b and then enter the first outlet pipe 2b through the second pressure relief branch 2d to flow back to the energy station 1. With this arrangement, the fluid in the pitch cylinder 100 is completely discharged, thereby avoiding the risk of the pitch drive system being operated under pressure and improving the reliability of the system.

With continued reference to fig. 3, in some alternative embodiments, the second driving module 3 further includes a third pressure relief branch 3c, where one end of the third pressure relief branch 3c is connected to the second inlet pipe 3a and the other end is connected to the second outlet pipe 3 b. The control valve group further comprises a sixth valve 46, and the sixth valve 46 is disposed on the third pressure relief branch 3c and is used for controlling on-off of the third pressure relief branch 3 c.

By controlling the sixth valve 46 to open, fluid in the locking telescopic cylinder 200 can flow out from the second inlet pipe 3a and then enter the second outlet pipe 3b from the third pressure relief branch 3c to flow back to the energy station 1, so that fluid in the locking telescopic cylinder 200 flows back to the energy station 1. With this arrangement, the fluid in the locking telescopic cylinder 200 is completely discharged, so that the risk brought by the pressurized operation of the pitch drive system is avoided, and the reliability of the system is improved.

Optionally, the control valve group may further comprise a second relief valve 16, the second relief valve 16 being arranged between the second inlet pipe 3a and the second outlet pipe 3b and in parallel with the sixth valve 46 for regulating the highest pressure of the pitch drive system. When the fluid flowing out of the energy station 1 from the second inlet pipe 3a exceeds the load of the pitch drive system, the fluid exceeding the load can flow back to the energy station 1 from the second outlet pipe 3b through the second overflow valve 16, so that the pressure stability of the pitch drive system is ensured, and the pitch drive system can stably operate.

Alternatively, the inlet of the second overflow valve 16 communicates with the outlet of the second valve 42, and the outlet of the second overflow valve 16 may be linked with the inlet of the second filter 15.

The embodiment of the application also provides a wind generating set, which comprises an impeller 500, a pitch system and a pitch driving system.

Impeller 500 includes a hub 510 and blades 520. The pitch system comprises a pitch bearing, a pitch telescopic cylinder 100 and a locking telescopic cylinder 200, wherein one of an inner ring and an outer ring of the pitch bearing is connected with a hub 510, the other is connected with a blade 520, the pitch telescopic cylinder 100 is used for driving the inner ring and the outer ring to rotate relatively, and the locking telescopic cylinder 200 is used for locking the relative arrangement of the blade 520 and the hub 510.

The first inlet pipe 2a of the pitch drive system is connected to one of the first rod chamber 101 and the first rodless chamber 102 of the pitch cylinder 100, the first outlet pipe 2b is connected to the other of the first rod chamber 101 and the first rodless chamber 102 of the pitch cylinder 100, the second inlet pipe 3a is connected to one of the second rod chamber 201 and the second rodless chamber 202 of the lock cylinder 200, and the second outlet pipe 3b is connected to the other of the second rod chamber 201 and the second rodless chamber 202.

Relative movement with hub 510 is enabled by the pitch drive system controlling locking telescoping cylinder 200 to unlock blade 520. The variable pitch drive system controls the variable pitch telescopic cylinder 100 to drive the inner ring and the outer ring of the variable pitch bearing to rotate relatively, so that the blades 520 are variable in pitch, and the variable pitch function of the blades 520 can be realized when the wind generating set is assembled or hoisted, and the operation is reliable.

The embodiment of the application also provides a method for performing pitch control by using the pitch drive system, referring to fig. 5, the pitch control method includes:

s100, the first inlet pipe 2a is connected to one of the first rod chamber 101 and the first rodless chamber 102 of the pitch telescopic cylinder 100, and the first outlet pipe 2b is connected to the other of the first rod chamber 101 and the first rodless chamber 102, while the second inlet pipe 3a is connected to one of the second rod chamber 201 and the second rodless chamber 202 of the lock telescopic cylinder 200, and the second outlet pipe 3b is connected to the other of the second rod chamber 201 and the second rodless chamber 202.

S200, disconnecting the first driving module 2 from the energy station 1 through the control valve group.

S300, driving the fluid in the power station 1 into the second rod cavity 201 of the locking telescopic cylinder 200, so that the locking telescopic cylinder 200 is contracted, and the blades 520 are unlocked from the hub 510.

S400, the first driving module 2 is communicated with the energy station 1 through the control valve group.

S500, driving fluid in the power station 1 to enter the first rod cavity 101 or the first rodless cavity 102 of the pitch telescopic cylinder 100, so that the blade 520 rotates relative to the hub 510, and pitch of the blade 520 is achieved.

Alternatively, in step S100, the first inlet pipe 2a is connected to the first rod-shaped chamber 101 of the pitch telescopic cylinder 100 and the first outlet pipe 2b is connected to the first rod-free chamber 102, while the second inlet pipe 3a is connected to the second rod-shaped chamber 201 of the lock telescopic cylinder 200 and the second outlet pipe 3b is connected to the second rod-free chamber 202.

In step S200, the first drive module 2 is disconnected from the energy station 1 by a control valve group. Optionally, the first valve 41, the fourth valve 44, the fifth valve 45 and the sixth valve 46 are controlled to be closed, so that the first driving module 2 is disconnected from the power station 1, and fluid of the power station 1 does not enter the first driving module 2.

In step S300, the second valve 42 is controlled to open to enable fluid in the power station 1 to enter the second rod chamber 201 of the locking telescopic cylinder 200, so that the locking telescopic cylinder 200 is contracted and the blade 520 is unlocked from the hub 510.

In step S400, the first drive module 2 is placed in communication with the energy station 1 via the control valve group. Alternatively, the first valve 41 is controlled to open, and the second valve 42 is controlled to close, so that fluid in the energy station 1 can enter the first rod chamber 101 of the telescopic cylinder,

in step S500, fluid in the power station 1 is driven into the first rod chamber 101 or the first rodless chamber 102 of the pitch cylinder 100, such that the blade 520 rotates relative to the hub 510, effecting pitch of the blade 520.

The method for performing pitch control by using the pitch driving system provided by the embodiment of the application can be used for meeting the requirement that the blade 520 can still perform pitch operation when the power supply of a unit is unavailable or the pitch operation is difficult due to the safety risk of the pitch driving system and the like. Moreover, according to the pitch control method, the pitch requirement, the unlocking before pitch, the locking requirement after pitch and the like can be guaranteed, and the reliability of a pitch control system is improved, so that the normal and stable operation of the wind generating set is guaranteed, and the pitch control method is effective and feasible.

While the application has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the application. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims

1. A pitch drive system for driving a pitch telescopic cylinder (100) and a locking telescopic cylinder (200), characterized in that the pitch drive system comprises:

an energy station (1), the energy station (1) being adapted to hold a fluid and being capable of providing power for the operation of the fluid;

a first driving module (2) including a first inlet pipe (2 a) and a first outlet pipe (2 b) arranged in pairs, wherein the first inlet pipe (2 a) and the first outlet pipe (2 b) are both connected between the energy station (1) and the pitch telescopic cylinder (100), the first inlet pipe (2 a) guides the fluid of the energy station (1) to one of a first rod cavity (101) and a first rodless cavity (102) of the pitch telescopic cylinder (100), and the first outlet pipe (2 b) guides the fluid of the other one of the first rod cavity (101) and the first rodless cavity (102) to the energy station (1);

A second driving module (3) including a second inlet pipe (3 a) and a second outlet pipe (3 b) arranged in pairs, the second inlet pipe (3 a) and the second outlet pipe (3 b) being connected between the energy station (1) and the locking telescopic cylinder (200), the second inlet pipe (3 a) guiding the fluid of the energy station (1) to one of a second rod-shaped cavity (201) and a second rodless cavity (202) of the locking telescopic cylinder (200), the second outlet pipe (3 b) guiding the fluid of the other of the second rod-shaped cavity (201) and the second rodless cavity (202) to the energy station (1);

the control valve group is arranged on the first driving module (2) and the second driving module (3), and the control valve group can control the connection or disconnection of at least one of the first driving module (2) and the second driving module (3) and the energy station (1).

2. A pitch drive system according to claim 1, wherein the control valve group comprises a first valve (41) and a second valve (42), the first valve (41) being arranged on the first inlet pipe (2 a), the first valve (41) being capable of controlling the connection or disconnection of the first inlet pipe (2 a);

the second valve (42) is arranged on the second outlet pipe (3 b), and the second valve (42) can control the connection or disconnection of the second outlet pipe (3 b).

3. A pitch drive system according to claim 2, wherein the second drive module (3) comprises a locking reversing valve (31), the locking reversing valve (31) being arranged between the locking telescopic cylinder (200) and the second valve (42), the second inlet pipe (3 a) and the second outlet pipe (3 b) being both connected to the locking reversing valve (31), the locking reversing valve (31) being switchable between a first state (S1) and a second state (S2);

in the first state (S1), the second inlet pipe (3 a) communicates with the second rod-shaped cavity (201), and the second outlet pipe (3 b) communicates with the second rod-free cavity (202);

in the second state (S2), the second inlet tube (3 a) communicates with the second rodless chamber (202), and the second outlet tube (3 b) communicates with the second rod-shaped chamber (201).

4. A pitch drive system according to claim 2, wherein the control valve group further comprises a third valve (43) arranged to the second inlet pipe (3 a), the second drive module (3) further comprising an accumulator (32), the accumulator (32) being connected to the second inlet pipe (3 a) downstream of the third valve (43);

the third valve (43) is a one-way valve (43 a) and is in one-way conduction from the energy station (1) to the locking telescopic cylinder (200).

5. The pitch drive system according to claim 2, wherein the first drive module (2) further comprises a pitch reversing valve (21), the pitch reversing valve (21) being arranged between the pitch telescopic cylinder (100) and the first valve (41), the first inlet pipe (2 a) and the first outlet pipe (2 b) being both connected to the pitch reversing valve (21), the pitch reversing valve (21) being switchable between a third state (S3) and a fourth state (S4);

in the third state (S3), the first inlet tube (2 a) communicates with the first rod-shaped cavity (101), and the first outlet tube (2 b) communicates with the first rodless cavity (102);

in the fourth state (S4), the first inlet tube (2 a) communicates with the first rodless cavity (102), and the first outlet tube (2 b) communicates with the first rod-shaped cavity (101).

6. The pitch drive system according to claim 5, wherein the first drive module (2) further comprises a bi-directional balancing valve (22), the bi-directional balancing valve (22) being arranged between the pitch telescopic cylinder (100) and the pitch reversing valve (21), the first inlet pipe (2 a) and the first outlet pipe (2 b) being both connected to the bi-directional balancing valve (22).

7. A pitch drive system according to any of claims 1-6, further comprising a quick connector (5), wherein a port of at least one of the first inlet pipe (2 a), the first outlet pipe (2 b), the second inlet pipe (3 a) and the second outlet pipe (3 b) facing away from the energy station (1) is connected with the quick connector (5).

8. A pitch drive system according to any one of claims 1-6, wherein the energy station (1) comprises a fluid inlet pipe (1 a) and a fluid outlet pipe (1 b), the fluid inlet pipe (1 a) being connected to the first inlet pipe (2 a) and the second inlet pipe (3 a), the fluid outlet pipe (1 b) being connected to the first outlet pipe (2 b) and the second outlet pipe (3 b);

the fluid outlet pipe (1 b) and the fluid inlet pipe (1 a) are connected with a first overflow valve (11).

9. The pitch drive system according to claim 8, wherein the first drive module (2) further comprises a first pressure relief branch (2 c) and a second pressure relief branch (2 d), one end of the first pressure relief branch (2 c) being in communication with the first inlet pipe (2 a) and the other end being in communication with the fluid outlet pipe (1 b), one end of the second pressure relief branch (2 d) being in communication with the first outlet pipe (2 b) and the other end being in communication with the fluid outlet pipe (1 b);

the control valve group further comprises a fourth valve (44) and a fifth valve (45), the fourth valve (44) is arranged on the first pressure relief branch (2 c) and used for controlling the on-off of the first pressure relief branch (2 c), and the fifth valve (45) is arranged on the second pressure relief branch (2 d) and used for controlling the on-off of the second pressure relief branch (2 d).

10. A pitch drive system according to any one of claims 1 to 6, wherein the second drive module (3) further comprises a third pressure relief branch (3 c), one end of the third pressure relief branch (3 c) being connected to the second inlet pipe (3 a) and the other end being connected to the second outlet pipe (3 b);

the control valve group further comprises a sixth valve (46), and the sixth valve (46) is arranged on the third pressure relief branch (3 c) and used for controlling the on-off of the third pressure relief branch (3 c).

11. A wind turbine generator set, comprising:

an impeller (500) comprising a hub (510) and blades (520);

the pitch system comprises a pitch bearing, a pitch telescopic cylinder (100) and a locking telescopic cylinder (200), wherein one of an inner ring and an outer ring of the pitch bearing is connected with the hub (510) and the other is connected with the blade (520), the pitch telescopic cylinder (100) is used for driving the inner ring and the outer ring to rotate relatively, and the locking telescopic cylinder (200) is used for locking the relative arrangement of the blade (520) and the hub (510);

the pitch drive system according to any one of claims 1 to 10, the first inlet pipe (2 a) being connected to one of a first rod cavity (101) and a first rodless cavity (102) of the pitch telescopic cylinder (100), the first outlet pipe (2 b) being connected to the other of the first rod cavity (101) and the first rodless cavity (102) of the pitch telescopic cylinder (100), the second inlet pipe (3 a) being connected to one of a second rod cavity (201) and a second rodless cavity (202) of the lock telescopic cylinder (200), the second outlet pipe (3 b) being connected to the other of the second rod cavity (201) and the second rodless cavity (202).

12. A method of pitch control using a pitch drive system according to any one of claims 1 to 10, comprising:

connecting the first inlet pipe (2 a) with one of a first rod cavity (101) and a first rodless cavity (102) of a pitch telescopic cylinder (100), and connecting the first outlet pipe (2 b) with the other of the first rod cavity (101) and the first rodless cavity (102), while connecting a second inlet pipe (3 a) with one of a second rod cavity (201) and a second rodless cavity (202) of a locking telescopic cylinder (200), and connecting the second outlet pipe (3 b) with the other of the second rod cavity (201) and the second rodless cavity (202);

disconnecting the first driving module (2) from the energy station (1) through the control valve group;

-driving the fluid in the energy station (1) into the second rod-like cavity (201) of the locking telescopic cylinder (200) so that the locking telescopic cylinder (200) is contracted, the blade (520) being unlocked from the hub (510);

the first driving module (2) is communicated with the energy station (1) through the control valve group;

driving fluid in the energy station (1) into the first rod cavity (101) or the first rodless cavity (102) of the pitch telescopic cylinder (100) so that the blade (520) rotates relative to the hub (510) to realize pitch of the blade (520).