A wind turbine generator unit variable pitch system

Abstract

This application discloses a pitch control system for a wind turbine generator set. The system includes a main control unit and a rectifier module. The main control unit and the rectifier module are connected to a charging module via DC slip rings. The charging module, backup power supply, inverter module, pitch motor, reducer, and blades are connected sequentially. The rectifier module supplies power to the charging module and charges the backup power supply. The backup power supply powers the inverter module in case of a rectifier module failure, allowing the blades to return to a safe position. The inverter module controls the pitch motor according to control commands. The pitch motor uses the reducer to decelerate and drive the blades to rotate according to a set pattern. When the power supply from the slip ring fails, the backup power supply powers the inverter module to return the blades to a safe position, ensuring the safety of the generator set. Furthermore, by powering the three inverter modules with the rectifier module to drive the motors, the number of rectifier modules and their total power are reduced, improving the efficiency of the rectifier module utilization.

Description

Technical Field

[0001] This application relates to the field of wind power generation, and more specifically, to a pitch control system for a wind turbine generator set. Background Technology

[0002] In recent years, to address global warming, countries have launched their own carbon emission reduction plans, including my country, which focuses on carbon peaking and carbon neutrality timelines. Developing clean energy is one of the key means to successfully achieve these plans. Wind power, as the most important clean energy source, has seen rapid development, with annual new installed capacity constantly reaching new highs. At the same time, China's domestic wind power technology has also made significant progress.

[0003] Wind power generation primarily uses wind energy to drive blades and generate electricity. In wind turbine generators, the pitch system, as a crucial core control system, regulates the overall power output and controls the aerodynamic braking of the blades. As the capacity of individual wind turbine generators increases, the load on the pitch system also grows, demanding higher output. Simultaneously, the need for cost reduction in the era of wind power parity places immense pressure on the cost of various components within the turbine. Currently, the primary technology employs a three-axis cabinet-type pitch system. Each axis control cabinet in this system contains a high-power servo driver, which drives a servo motor to control the blade movement. However, this system presents several problems during operation. For example, the large size of the driver results in a large axis control cabinet, and the three cabinets must be distributed across three surfaces of the hub, connected by heavy-duty cables, leading to complex wiring and high costs.

[0004] Therefore, there is an urgent need in this field for a simpler and lower-cost pitch system solution. Summary of the Invention

[0005] The purpose of this application is to overcome the shortcomings of existing technologies and provide a pitch control system for wind turbine generator sets. When the main power supply of the pitch control system is abnormal, the system can supply power to the inverter module through the backup power supply to control the blades to return to a safe position and ensure the safety of the generator set.

[0006] The objective of this application is achieved through the following technical solution:

[0007] In a first aspect, this application proposes a wind turbine generator pitch system, the system including a wind turbine main control unit and a rectifier module, the wind turbine main control unit and the rectifier module being connected to a charging module via a DC slip ring, and the charging module, backup power supply, inverter module, pitch motor, reducer and blades being connected in sequence;

[0008] The rectifier module is used to supply power to the charging module and charge the backup power supply. The backup power supply is used to supply power to the inverter module in the event of a rectifier module failure, so that the blades return to a safe position.

[0009] The inverter module is used to control the pitch motor according to the control command. The pitch motor uses the reducer to reduce speed and drive the blades to rotate in a set manner.

[0010] In one possible implementation, the wind turbine main control unit and the rectifier module are also directly connected to the inverter module through the DC slip ring. The wind turbine main control unit is used to issue control commands to the inverter module. The rectifier module is arranged in the nacelle and is used to convert AC power into DC power to power the inverter module.

[0011] In one possible implementation, the backup power supply is connected to the inverter module via a diode, ensuring that the backup power supply provides power to the inverter module in one direction only.

[0012] In one possible implementation, the inverter module integrates a PLC controller and DI and DO ports.

[0013] In one possible implementation, the wind turbine main control unit is also used to output a safety chain signal in the event of a fault, which is input to the DI port of the inverter module through the DC slip ring to control the blade feathering protection.

[0014] In one possible implementation, the system further includes a position sensor connected to the inverter module and the pitch motor, for feeding back the status information of the pitch motor to the inverter module.

[0015] In one possible implementation, the system further includes a limit switch that feeds back information about the blades reaching a safe position to the inverter module via a normally open contact.

[0016] In one possible implementation, the wind turbine main control unit is connected in series with the DC slip ring and the inverter module via a dedicated communication cable.

[0017] In one possible implementation, there are three lines that sequentially connect the charging module, the backup power supply, the inverter module, the pitch motor, the speed reducer, and the propeller.

[0018] In one possible implementation, the charging module internally integrates a DC / DC module.

[0019] The main solution and its various further alternatives described above can be freely combined to form multiple solutions, all of which are solutions that can be adopted and are claimed in this application; furthermore, the (non-conflicting alternatives) can also be freely combined with each other and with other alternatives. Those skilled in the art, after understanding the solution of this application, will realize from the prior art and common general knowledge that there are many combinations, all of which are technical solutions to be protected by this application, and will not be exhaustively listed here.

[0020] This application discloses a pitch control system for a wind turbine generator set. The system includes a main control unit and a rectifier module. The main control unit and the rectifier module are connected to a charging module via DC slip rings. The charging module, backup power supply, inverter module, pitch motor, reducer, and blades are connected sequentially. The rectifier module supplies power to the charging module and charges the backup power supply. The backup power supply powers the inverter module in case of a rectifier module failure, allowing the blades to return to a safe position. The inverter module controls the pitch motor according to control commands. The pitch motor uses the reducer to decelerate and drive the blades to rotate according to a set pattern. When the power supply from the slip ring fails, the backup power supply powers the inverter module to return the blades to a safe position, ensuring the safety of the generator set. Furthermore, by powering the three inverter modules with the rectifier module to drive the motors, the number of rectifier modules and their total power are reduced, improving the efficiency of the rectifier module utilization. Attached Figure Description

[0021] Figure 1 A schematic diagram of the wind turbine pitch system proposed in an embodiment of this application is shown.

[0022] Figure 2 A connection diagram of the communication network provided in an embodiment of this application is shown.

[0023] Figure 3 A schematic diagram of a safety chain loop provided in an embodiment of this application is shown.

[0024] Figure 4 A schematic diagram of the diode connection provided in an embodiment of this application is shown.

[0025] Figure 5 A comparison diagram is shown between the wind turbine pitch system provided in this application embodiment and an existing system.

[0026] Icons: 1- Main control unit of the wind turbine; 2- Rectifier module; 3- DC slip ring; 4- Charging module; 5- Backup power supply; 6- Inverter module; 7- Pitch motor; 8- Gearbox; 9- Blade; 10- Position sensor; 11- Limit switch; 12- Diode. Detailed Implementation

[0027] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, unless otherwise specified, the following embodiments and features in the embodiments can be combined with each other.

[0028] Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] In existing technologies, due to the increasing single-unit capacity of wind turbines, the load on the pitch system is also constantly increasing. This requires the pitch system to have higher output. At the same time, with the advent of wind power parity, there is a need to continuously reduce the cost of the turbine, resulting in enormous cost pressure on each component of the wind turbine. Currently, the main technology used is a three-axis cabinet-type pitch system. Each axis control cabinet in this system is equipped with a high-power servo driver, which drives a servo motor to control the movement of the blades. However, this system has some problems during operation. For example, the large size of the driver results in a large axis control cabinet. In addition, the three axis control cabinets must be distributed on three sides of the hub and connected by heavy-duty cables, which makes the system wiring complex and costly.

[0030] Therefore, to address the aforementioned issues, this application proposes a wind turbine pitch control system that is simpler and less costly than existing systems. In this system, when the main power supply of the pitch control system is abnormal, the system can supply power to the inverter module 6 via the backup power supply 5, controlling the blades 9 to return to a safe position, ensuring the safety of the turbine. A detailed description follows.

[0031] This application provides a wind turbine generator pitch system, which includes a wind turbine main control unit 1 and a rectifier module 2. The wind turbine main control unit 1 and the rectifier module 2 are connected to a charging module 4 through a DC slip ring 3. The charging module 4, the backup power supply 5, the inverter module 6, the pitch motor 7, the reducer 8 and the blades 9 are connected in sequence.

[0032] The rectifier module 2 is used to power the charging module 4 and charge the backup power supply 5. The backup power supply 5 is used to power the inverter module 6 in the event of a failure of the rectifier module 2, so that the blade 9 returns to a safe position.

[0033] Inverter module 6 is used to control pitch motor 7 according to control commands. Pitch motor 7 uses reducer 8 to reduce speed and drive blade 9 to rotate in a set manner.

[0034] The wind turbine main control unit 1 and the rectifier module 2 are also directly connected to the inverter module 6 via a DC slip ring 3. The wind turbine main control unit 1 is used to send control commands to the inverter module 6. The rectifier module 2, located in the nacelle, is used to convert AC power to DC power to supply power to the inverter module 6. The rectifier module 2, located in the nacelle, can reduce the volume of equipment inside the hub and optimize the layout inside the hub. In addition, compared with AC slip rings, the DC slip ring 3 used in this embodiment can reduce the number of power loops and reduce slip ring costs.

[0035] There are three lines that connect the charging module 4, backup power supply 5, inverter module 6, pitch motor 7, reducer 8, and blade 9 in sequence. The three inverter modules 6 control the three pitch motors 7 respectively. The charging module 4 integrates a DC / DC module, which converts the input DC voltage into a specific charging voltage to charge the backup power supply 5. When there is a power failure from the slip ring, the backup power supply 5 supplies power to the inverter module 6, which then controls the pitch motor 7 to return the blade 9 to a safe position, ensuring the safety of the unit. This safe position is also called the storm position, where the blade 9 experiences minimal wind force.

[0036] In addition, inverter module 6 integrates a DC / AC module to convert the DC power from DC slip ring 3 into a controllable AC power. Inverter module 6 also integrates a PLC controller and DI and DO ports. The controller communicates with the main control unit 1 via a fieldbus, receives control commands, and provides feedback on the system status.

[0037] Figure 2 The diagram shows the connection of the communication network provided in this embodiment. The wind turbine pitch system also includes a communication network, and the wind turbine main control unit 1 is connected in series with the DC slip ring 3 and the inverter module 6 via a dedicated communication cable. Figure 3 A schematic diagram of the safety chain loop provided in the embodiment of this application is shown. By designing a hardware safety chain, the wind turbine main control unit 1 outputs a safety chain signal in the event of a fault. The signal is input to the DI port of the inverter module 6 through the DC slip ring 3 to control the feathering protection of the blades 9.

[0038] The specific steps are as follows: Each inverter module 6 includes a DI point for a safety chain signal input. The main control module outputs a hardware safety chain signal, which passes through a slip ring to the DI point on the inverter module 6. When a serious fault occurs in the wind turbine that may threaten the safety of the unit, the safety chain signal from the main control module is disconnected, the signal on the DI point of the inverter module 6 becomes low, and the inverter module 6 controls the blades 9 to feather, protecting the safety of the unit.

[0039] Figure 4The diagram shows the connection of diode 12 provided in the embodiment of this application. The backup power supply 5 is connected to the inverter module 6 through diode 12, ensuring that the backup power supply 5 supplies power to the inverter module 6 in one direction and does not supply power to the backup power supply 5 in the reverse direction.

[0040] and Figure 5 The diagram shows a comparison between the wind turbine pitch system provided in this application and an existing system. The rectifier module 2 of the wind turbine pitch system provided in this application can simultaneously power three inverter modules 6, while the existing pitch system includes three independent servo drives, and each servo drive includes a rectifier module 2 and an inverter module 6. The existing pitch system of this application reduces two rectifier modules, and because the pitch load is an alternating load, the loads on the three blades 9 will not reach their maximum values ​​simultaneously. Therefore, the power P of one large rectifier module is less than the power P of the rectifier modules in the three drives.

[0041] In addition, the rectifier module is located in the nacelle, which reduces the volume of the equipment inside the hub. Furthermore, since the inside of the hub is a continuous rotating and vibrating environment, the installation design requirements for the nacelle are much lower than those for the inside of the hub, which can greatly reduce design and installation costs.

[0042] Compared to the AC slip rings in existing pitch systems, the DC slip ring 3 can reduce two power tracks, thus lowering the slip ring cost. The DC slip ring only requires three tracks: "+", "-", and "PE", while the AC slip ring requires "L1", "L2", "L3", "N", and "PE".

[0043] The wind turbine pitch system proposed in this application also includes a position sensor 10, which is connected to the inverter module 6 and the pitch motor 7. The position sensor 10 is used to feed back the status information of the pitch motor 7 to the inverter module 6, and the inverter module 6 performs closed-loop control through the feedback signal.

[0044] The system also includes a limit switch 11, which feeds back information about the blade 9 reaching a safe position to the inverter module 6 via its normally open contact. The limit switch 11 is installed on the inner wall of the hub. When the pitch motor 7 drives the blade 9 to feather, the internal bearing of the blade 9 drives the limit stop block to rotate. When the safe position is reached, the limit stop block triggers the limit switch 11, closing its normally open contact, completing the circuit, and feeding the signal back to the inverter module 6.

[0045] Compared with the prior art, the embodiments of this application have the following beneficial effects:

[0046] 1. By using one rectifier module to power three inverter modules simultaneously to drive the motor, the number of rectifier modules and total power are reduced, and the efficiency of rectifier module utilization is improved.

[0047] 2. The rectifier module is located in the engine compartment, which makes it easier to design and install, reduces the volume of equipment inside the wheel hub, and optimizes the layout and wiring.

[0048] 3. Use DC slip rings to reduce the number of power loops and lower slip ring costs.

[0049] In summary, this application discloses a pitch control system for a wind turbine generator set. The system includes a main control unit and a rectifier module. The main control unit and the rectifier module are connected to a charging module via DC slip rings. The charging module, backup power supply, inverter module, pitch motor, reducer, and blades are connected sequentially. The rectifier module supplies power to the charging module and charges the backup power supply. The backup power supply provides power to the inverter module in case of a rectifier module failure, allowing the blades to return to a safe position. The inverter module controls the pitch motor according to control commands. The pitch motor uses the reducer to decelerate and drive the blades to rotate according to a set pattern. When the power supply from the slip ring fails, the backup power supply powers the inverter module to return the blades to a safe position, ensuring the safety of the generator set. Furthermore, by using the rectifier module to power the three inverter modules and drive the motors, the number of rectifier modules and their total power are reduced, improving the efficiency of the rectifier module utilization.

[0050] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A wind turbine generator system, characterized by, The system comprises a fan master control unit and a rectifier module, the fan master control unit and the rectifier module are connected with a charging module through a direct current slip ring, the charging module, a backup power supply, an inverter module, a variable pitch motor, a speed reducer and a blade are sequentially connected, the fan master control unit and the rectifier module are also directly connected with the inverter module through the direct current slip ring, the fan master control unit is used to send a control instruction to the inverter module, the rectifier module is arranged in a cabin and is used to convert alternating current into direct current to supply power for the inverter module, and a PLC controller and DI and DO ports are integrated in the inverter module; The rectifier module is used to supply power for the charging module and charge the backup power supply, and the backup power supply is used to supply power for the inverter module in the case of failure of the rectifier module, so that the blade returns to a safe position; The inverter module is used to control the variable pitch motor according to the control instruction, the variable pitch motor drives the blade to rotate in a set mode by using the speed reducer for speed reduction; The fan master control unit is also used to output a safety chain signal in the case of failure, the safety chain signal is input to a DI port of the inverter module through the direct current slip ring, and the blade is controlled to be feathered for protection; The system further comprises a position sensor, the position sensor is connected with the inverter module and the variable pitch motor and is used to feed back state information of the variable pitch motor to the inverter module. The system further comprises a limit switch, the limit switch feeds back information that the blade reaches the safe position to the inverter module through a normally open contact.

2. The wind turbine generator system variable pitch system of claim 1, wherein, The backup power supply is connected with the inverter module through a diode, so that the backup power supply supplies power for the inverter module in one direction.

3. The wind turbine generator set variable pitch system in accordance with claim 1, wherein, The fan master control unit is connected with the direct current slip ring and the inverter module in series through a special communication cable.

4. The wind turbine generator set variable pitch system in accordance with claim 1, wherein, There are three lines for sequentially connecting the charging module, the backup power supply, the inverter module, the variable pitch motor, the speed reducer and the blade.

5. The wind turbine generator set variable pitch system in accordance with claim 1, wherein, A DC / DC module is integrated in the charging module.

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