A wind turbine dual-drive electric pitch control system and control method

Abstract

The present invention discloses a wind turbine dual-drive electric pitch control system and control method. The system comprises a main controller, a main driver, a main motor, and a main position and speed sensor electrically connected in sequence; a main motor, a main reducer, and a pitch bearing mechanically connected in sequence; the main position and speed sensor being electrically connected to the main driver; and a slave driver, a slave motor, and a slave reducer. The main driver, slave driver, and slave motor are electrically connected in sequence, and the slave motor, slave reducer, and pitch bearing are mechanically connected in sequence. The present invention solves the problems existing in the prior art, such as large tooth stress concentration, high single tooth load, severe wear and even fatigue damage, and endangerment to wind turbine safety.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine pitch control, and in particular to a wind turbine dual-drive electric pitch control system and a control method. Background Art

[0002] A wind turbine generator consists of a rotor and a generator. The rotor includes blades, a hub, and reinforcements. The blades rotate in response to wind power, generating electricity, while the generator head rotates. A wind power source consists of the wind turbine, a tower supporting the turbine, a battery charge controller, an inverter, an unloader, a grid connection controller, and a battery bank.

[0003] As economically viable wind resources on land become increasingly scarce, offshore wind power offers advantages over onshore wind power, such as higher wind energy content, reduced wind shear, lower turbulence, and less environmental impact. Consequently, global wind farm construction is trending from land to sea. Currently, my country's offshore wind power sector is developing towards larger turbines. The variable pitch system, a crucial component of wind turbine control systems, directly impacts turbine performance and safety, with functions such as adjusting rotor input power and providing pneumatic braking.

[0004] Existing pitch control systems all use a single driver to drive a single motor, which in turn drives the pitch bearing through a single pitch reduction gearbox, ultimately driving the entire blade to perform pitch control. During this process, the small teeth of the pitch reduction gearbox only act on a few large teeth of the pitch bearing, which bear the load of the entire blade. This can easily cause stress concentration on these large teeth, leading to severe wear and even fatigue damage. In extreme cases, pitch control cannot be achieved, endangering wind turbine safety.

[0005] Therefore, there is an urgent need for a new control technology that can reduce the single tooth load of the pitch bearing and improve the safety of wind turbines. Summary of the Invention

[0006] In order to overcome the shortcomings of the existing technology, the present invention provides a wind turbine dual-drive electric pitch control system and control method to solve the problems existing in the existing technology such as large tooth stress concentration, high single tooth load, severe wear and even fatigue damage, and endangerment to wind turbine safety.

[0007] The technical solution adopted by the present invention to solve the above problems is:

[0008] A wind turbine dual-drive electric pitch control system includes a main controller, a main drive, a main motor, and a main position and speed sensor electrically connected in sequence, and a main motor, a main reducer, and a pitch bearing mechanically connected in sequence, wherein the main position and speed sensor is electrically connected to the main drive, and further includes a slave drive, a slave motor, and a slave reducer, wherein the main drive, slave drive, and slave motor are electrically connected in sequence, and the slave motor, slave reducer, and pitch bearing are mechanically connected in sequence.

[0009] The main controller, main drive, main motor, main reducer, and pitch bearing constitute the main drive circuit, and the main controller, main drive (part of it), slave drive, slave motor, slave reducer, and pitch bearing constitute the slave drive circuit. The dual drive circuits share the stress concentration of the large teeth, reduce the load on a single tooth, effectively reduce severe wear and even fatigue damage of the large teeth, and improve the safety of the wind turbine.

[0010] As a preferred technical solution, the master driver includes a position-speed signal conversion module and a position controller, a speed controller, a current controller, a main power converter, and a main current sensor electrically connected in sequence. The input end of the position-speed signal conversion module is connected to the output end of the main position-speed sensor, and the output end of the position-speed signal conversion module is electrically connected to the input end of the position controller and the input end of the speed controller, respectively. The slave driver includes a slave current controller, a slave power converter, and a slave current sensor electrically connected in sequence. The output end of the speed controller is electrically connected to the input end of the slave current controller, and the output end of the slave current sensor is electrically connected to the input end of the slave current controller and the slave motor, respectively.

[0011] Position loop control is achieved by comparing the position control command given by the master controller with the actual position value of the main motor. Speed ​​loop control is achieved by comparing the speed command given by the position loop with the actual speed value of the main motor. Main current loop control is achieved by comparing the current command given by the speed loop with the actual current value of the main motor. The slave current controller achieves slave current loop control by comparing the received current command control (slave torque command) with the actual current value received by the slave motor. The slave motor drives the slave reducer and drives the blade bearing. This achieves torque synchronization of the dual-drive electric pitch system, reduces pitch bearing stress, reduces single tooth load, and improves the safety and reliability of the pitch system.

[0012] Preferably, the position controller is further configured to feed back actual position information to the main controller, and the main controller is further configured to receive the actual position information. This allows the main controller to promptly collect the actual position information in the loop, giving the main controller the ability to monitor the actual position information in the loop, making it easier to control the actual pitch control status and facilitating more precise control.

[0013] As a preferred technical solution, the slave driver further includes a speed limiter electrically connected to the output end of the position controller and the input end of the slave power converter respectively.

[0014] The speed limiter is used to receive a speed instruction sent by the position controller and output a speed instruction with a limited speed.

[0015] The speed command of the main drive circuit after passing through the position loop controller is given to the slave power converter after passing through the speed limiter. The current control command (slave given torque command) output by the main drive circuit after passing through the current loop controller is directly transmitted to the slave driver. The slave driver controls the action of the slave motor according to the received speed limit command and current command (slave given torque command), thereby realizing torque synchronization and anti-backlash control of the dual-drive electric pitch with speed limitation, further reducing the stress of the pitch bearing, reducing the single tooth load, and improving the safety and reliability of the pitch system.

[0016] As a preferred technical solution, the master power converter and / or the slave power converter is a PWM inverter.

[0017] The PWM inverter has fast adjustment speed, good power factor and simple structure.

[0018] As a preferred technical solution, the main position and speed sensor is a rotary transformer.

[0019] Resolvers are precision angle, position, and speed detection devices, particularly suited for applications where rotary encoders struggle, such as those characterized by high temperatures, high dust levels, extreme cold, humidity, high speeds, and high vibration. They offer high accuracy, simple structure, agile operation, reliable operation, and minimal environmental requirements (especially in high-temperature and high-dust environments). They also offer high output signal amplitude and strong anti-interference capabilities. Their use in the main drive circuit facilitates simultaneous position and speed detection, enhancing integration.

[0020] As a preferred technical solution, it also includes a slave position speed sensor electrically connected to the slave motor.

[0021] The arrangement of the slave position and speed sensor facilitates the switching between the master drive circuit and the slave drive circuit. When the master drive circuit and the slave drive circuit need to be switched, it is easy to switch the original master drive circuit to the slave drive circuit, or to switch the original slave drive circuit to the master drive circuit.

[0022] As a preferred technical solution, the slave position speed sensor is a rotary transformer.

[0023] A resolver is a precision angle, position, and speed detection device, particularly suited for applications where rotary encoders may not function properly, such as those characterized by high temperatures, high dust levels, extreme cold, humidity, high speeds, and high vibration. It offers high monitoring accuracy, simple structure, sensitive operation, reliable operation, low environmental requirements (especially in high-temperature and high-dust environments), large output signal amplitude, and strong anti-interference capabilities. When switching from a master drive circuit to a slave drive circuit, or vice versa, it facilitates auxiliary feedback and correction of position and speed detection information, resulting in more precise control.

[0024] As a preferred technical solution, it also includes a pitch controller, and the main controller, pitch controller, and position controller are electrically connected in sequence.

[0025] The pitch controller plays the role of transferring and correcting position information, facilitating the regulation of position control instructions and providing more I / O points.

[0026] A control method for a wind turbine dual-drive electric pitch control system, comprising the following steps:

[0027] S1, the main controller sends the position control command to the main driver;

[0028] S2, the master driver receives the position control command, combines the actual position information and actual speed information of the master motor fed back by the master position and speed sensor to drive the master motor to work, and controls the slave driver to drive the slave motor to work;

[0029] S3, the main motor drives the main reducer to work, and the slave motor drives the slave reducer to work;

[0030] S4, the main position and speed sensor detects and outputs the actual position information and actual speed information of the main motor to the main driver;

[0031] S5. The main reducer drives the variable pitch bearing to work, and the slave reducer drives the variable pitch bearing to work.

[0032] The main controller, main drive, main motor, main reducer, and pitch bearing constitute the main drive circuit, and the main controller, main drive (part of it), slave drive, slave motor, slave reducer, and pitch bearing constitute the slave drive circuit. The dual drive circuits share the stress concentration of the large teeth, reduce the load on a single tooth, effectively reduce severe wear and even fatigue damage of the large teeth, and improve the safety of the wind turbine.

[0033] As a preferred technical solution, a control method for a wind turbine dual-drive electric pitch control system is provided, wherein the master driver comprises a position controller, a speed controller, a main current controller, a main power converter, a main current sensor, and a position-speed signal conversion module connected in sequence, and the slave driver comprises a slave current controller, a slave power converter, and a slave current sensor;

[0034] Step S1 specifically includes the following steps:

[0035] K1, the main controller sends the position control instruction to the position controller;

[0036] Step S2 specifically includes the following steps:

[0037] K2, the position controller receives the position control command, combines the actual position information of the main motor fed back by the main position speed sensor and the position speed signal conversion module, and sends the speed command to the speed controller;

[0038] K3, the speed controller receives the speed command, combines the actual speed information of the main motor fed back by the main position speed sensor and the position speed signal conversion module, and sends the torque command to the main current controller and the slave current controller;

[0039] K4, the main current controller receives the torque command, combines the actual current information of the main motor output by the main current sensor, and sends an output signal to control the main power converter;

[0040] K5, the main power converter receives the output signal sent by the main current controller and outputs the current information after power conversion to the main current sensor;

[0041] K6, the main current sensor receives the current information output by the main power converter, detects the actual current information of the main motor and feeds the actual current information of the main motor back to the input end of the main current controller;

[0042] K7, the position and speed signal conversion module receives and converts the actual position information and actual speed information of the main motor fed back by the main position and speed sensor, and transmits the actual position information to the input end of the position controller and the actual speed information to the input end of the speed controller;

[0043] K8, receives the torque command from the current controller, combines it with the actual current information of the slave motor fed back from the current sensor, and sends an output signal to control the slave power converter;

[0044] K9, the slave power converter receives the output signal sent from the slave current controller, and outputs the current information after power conversion to the slave current sensor;

[0045] K10, receiving the current information output from the power converter from the current sensor, detecting the actual current information from the motor and feeding back the actual current information from the motor to the input end of the slave current controller;

[0046] Step S4 specifically includes the following steps:

[0047] K11, the main position and speed sensor detects and outputs the actual position information and actual speed information of the main motor to the position and speed signal conversion module.

[0048] Position loop control is achieved by comparing the position control command given by the master controller with the actual position value of the main motor. Speed ​​loop control is achieved by comparing the speed command given by the position loop with the actual speed value of the main motor. Main current loop control is achieved by comparing the current command given by the speed loop with the actual current value of the main motor. The slave current controller achieves slave current loop control by comparing the received current command control (slave torque command) with the actual current value received by the slave motor. The slave motor drives the slave reducer and drives the blade bearing. This achieves torque synchronization of the dual-drive electric pitch system, reduces pitch bearing stress, reduces single tooth load, and improves the safety and reliability of the pitch system.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] (1) The present invention adopts a dual drive circuit to share the stress concentration of the large teeth, reduce the load on a single tooth, effectively reduce the serious wear and even fatigue damage of the large teeth, and improve the safety of the fan;

[0051] (2) The present invention realizes torque synchronization and backlash elimination control of dual-drive electric variable pitch with speed limitation;

[0052] (3) The present invention further reduces the stress of the pitch bearing, reduces the load on a single tooth, and improves the safety and reliability of the pitch system;

[0053] (4) The present invention has fast adjustment speed, good power factor and simple structure;

[0054] (5) The present invention facilitates simultaneous position and speed detection, and the degree of integration is improved;

[0055] (6) The present invention has high monitoring accuracy, simple structure, sensitive action, reliable operation, low requirements on environmental conditions, large output signal amplitude and strong anti-interference ability, improved integration and more precise control;

[0056] (7) The present invention facilitates the regulation of position control instructions and also facilitates the provision of more I / O points. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a structural schematic diagram of the present invention;

[0058] Figure 2 for Figure 1 A partial enlarged view of . DETAILED DESCRIPTION

[0059] The present invention will be further described in detail below with reference to the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0060] Example 1

[0061] like Figure 1 、 Figure 2 As shown, a wind turbine dual-drive electric pitch control system includes a main controller, a main drive, a main motor, and a main position speed sensor electrically connected in sequence, and a main motor, a main reducer, and a pitch bearing mechanically connected in sequence. The main position speed sensor is electrically connected to the main drive, and also includes a slave drive, a slave motor, and a slave reducer. The main drive, slave drive, and slave motor are electrically connected in sequence, and the slave motor, slave reducer, and pitch bearing are mechanically connected in sequence.

[0062] When working, the system performs the following steps:

[0063] S1, the main controller sends the position control command to the main driver;

[0064] S2, the master driver receives the position control command, combines the actual position information and actual speed information of the master motor fed back by the master position and speed sensor to drive the master motor to work, and controls the slave driver to drive the slave motor to work;

[0065] S3, the main motor drives the main reducer to work, and the slave motor drives the slave reducer to work;

[0066] S4, the main position and speed sensor detects and outputs the actual position information and actual speed information of the main motor to the main driver;

[0067] S5. The main reducer drives the variable pitch bearing to work, and the slave reducer drives the variable pitch bearing to work.

[0068] It is worth noting that because the system operates dynamically, the flow of electrical signals is also dynamic, and there is feedback, so the above steps do not have only one order.

[0069] The main drive circuit consists of the master controller, main drive, main motor, main reducer, and pitch bearing. The slave drive circuit consists of the master controller, main drive (partially), slave drive, slave motor, slave reducer, and pitch bearing. These dual drive circuits distribute stress concentration on the main teeth, reducing the load on a single tooth. This effectively reduces severe wear and even fatigue damage on the main teeth, thereby improving turbine safety. Optimally, the master drive circuit and the slave drive circuit each share half of the main tooth stress.

[0070] As a preferred technical solution, the master driver includes a position-speed signal conversion module and a position controller, a speed controller, a current controller, a main power converter, and a main current sensor electrically connected in sequence. The input end of the position-speed signal conversion module is connected to the output end of the main position-speed sensor, and the output end of the position-speed signal conversion module is electrically connected to the input end of the position controller and the input end of the speed controller, respectively. The slave driver includes a slave current controller, a slave power converter, and a slave current sensor electrically connected in sequence. The output end of the speed controller is electrically connected to the input end of the slave current controller, and the output end of the slave current sensor is electrically connected to the input end of the slave current controller and the slave motor, respectively.

[0071] When working, this preferred solution performs more detailed steps relative to the above solution, as follows:

[0072] Step S1 specifically includes the following steps:

[0073] K1, the main controller sends the position control instruction to the position controller;

[0074] Step S2 specifically includes the following steps:

[0075] K2, the position controller receives the position control command, combines the actual position information of the main motor fed back by the main position speed sensor and the position speed signal conversion module, and sends the speed command to the speed controller;

[0076] K3, the speed controller receives the speed command, combines the actual speed information of the main motor fed back by the main position speed sensor and the position speed signal conversion module, and sends the torque command to the main current controller and the slave current controller;

[0077] K4, the main current controller receives the torque command, combines the actual current information of the main motor output by the main current sensor, and sends an output signal to control the main power converter;

[0078] K5, the main power converter receives the output signal sent by the main current controller and outputs the current information after power conversion to the main current sensor;

[0079] K6, the main current sensor receives the current information output by the main power converter, detects the actual current information of the main motor and feeds the actual current information of the main motor back to the input end of the main current controller;

[0080] K7, the position and speed signal conversion module receives and converts the actual position information and actual speed information of the main motor fed back by the main position and speed sensor, and transmits the actual position information to the input end of the position controller and the actual speed information to the input end of the speed controller;

[0081] K8, receives the torque command from the current controller, combines it with the actual current information of the slave motor fed back from the current sensor, and sends an output signal to control the slave power converter;

[0082] K9, the slave power converter receives the output signal sent from the slave current controller, and outputs the current information after power conversion to the slave current sensor;

[0083] K10, receiving the current information output from the power converter from the current sensor, detecting the actual current information from the motor and feeding back the actual current information from the motor to the input end of the slave current controller;

[0084] Step S4 specifically includes the following steps:

[0085] K11, the main position and speed sensor detects and outputs the actual position information and actual speed information of the main motor to the position and speed signal conversion module.

[0086] It is worth noting that because the system operates dynamically, the flow of electrical signals is also dynamic, and there is feedback, so the above steps do not have only one order.

[0087] Position loop control is achieved by comparing the position control command given by the master controller with the actual position value of the main motor. Speed ​​loop control is achieved by comparing the speed command given by the position loop with the actual speed value of the main motor. Main current loop control is achieved by comparing the current command given by the speed loop with the actual current value of the main motor. The slave current controller achieves slave current loop control by comparing the received current command control (slave torque command) with the actual current value received by the slave motor. The slave motor drives the slave reducer and drives the blade bearing. This achieves torque synchronization of the dual-drive electric pitch system, reduces pitch bearing stress, reduces single tooth load, and improves the safety and reliability of the pitch system.

[0088] Preferably, the position controller is further configured to feed back actual position information to the main controller, and the main controller is further configured to receive the actual position information. This allows the main controller to promptly collect the actual position information in the loop, giving the main controller the ability to monitor the actual position information in the loop, making it easier to control the actual pitch control status and facilitating more precise control.

[0089] As a preferred technical solution, the slave driver further includes a speed limiter electrically connected to the output end of the position controller and the input end of the slave power converter respectively.

[0090] The speed limiter is used to receive a speed instruction sent by the position controller and output a speed instruction with a limited speed.

[0091] The speed command of the main drive circuit after passing through the position loop controller is given to the slave power converter after passing through the speed limiter. The current control command (slave given torque command) output by the main drive circuit after passing through the current loop controller is directly transmitted to the slave driver. The slave driver controls the action of the slave motor according to the received speed limit command and current command (slave given torque command), thereby realizing torque synchronization and anti-backlash control of the dual-drive electric pitch with speed limitation, further reducing the stress of the pitch bearing, reducing the single tooth load, and improving the safety and reliability of the pitch system.

[0092] In this embodiment, the current of the main drive circuit is transmitted to the slave drive circuit, and the load borne by the master / slave motor is distributed, so that the torque difference between the master / slave drive circuits can be controlled to less than 5%; at the same time, the speed set value transmitted from the main drive circuit to the slave drive circuit is limited, thereby eliminating the tooth gap error that is inevitably present in the assembly and manufacturing process of the reducer, avoiding the situation in which only one motor is in actual contact and action with the reducer teeth during actual operation, controlling the speed difference between the master / slave drive circuits to less than 5%, realizing torque synchronization control within the speed limit of the master / slave motor, reducing the fatigue load and limit load of a single tooth of the variable pitch bearing, reducing the damage rate of the variable pitch bearing due to excessive stress on a single tooth, and improving the safety and reliability of the wind turbine.

[0093] As a preferred technical solution, the master power converter and / or the slave power converter is a PWM inverter.

[0094] The PWM inverter has fast adjustment speed, good power factor and simple structure.

[0095] As a preferred technical solution, the main position and speed sensor is a rotary transformer.

[0096] Resolvers are precision angle, position, and speed detection devices, particularly suited for applications where rotary encoders struggle, such as those characterized by high temperatures, high dust levels, extreme cold, humidity, high speeds, and high vibration. They offer high accuracy, simple structure, agile operation, reliable operation, and minimal environmental requirements (especially in high-temperature and high-dust environments). They also offer high output signal amplitude and strong anti-interference capabilities. Their use in the main drive circuit facilitates simultaneous position and speed detection, enhancing integration.

[0097] As a preferred technical solution, it also includes a slave position speed sensor electrically connected to the slave motor.

[0098] The arrangement of the slave position and speed sensor facilitates the switching between the master drive circuit and the slave drive circuit. When the master drive circuit and the slave drive circuit need to be switched, it is easy to switch the original master drive circuit to the slave drive circuit, or to switch the original slave drive circuit to the master drive circuit.

[0099] As a preferred technical solution, the slave position speed sensor is a rotary transformer.

[0100] A resolver is a precision angle, position, and speed detection device, particularly suited for applications where rotary encoders may not function properly, such as those characterized by high temperatures, high dust levels, extreme cold, humidity, high speeds, and high vibration. It offers high monitoring accuracy, simple structure, sensitive operation, reliable operation, low environmental requirements (especially in high-temperature and high-dust environments), large output signal amplitude, and strong anti-interference capabilities. When switching from a master drive circuit to a slave drive circuit, or vice versa, it facilitates auxiliary feedback and correction of position and speed detection information, resulting in more precise control.

[0101] As a preferred technical solution, it also includes a pitch controller, and the main controller, pitch controller, and position controller are electrically connected in sequence.

[0102] The pitch controller plays the role of transferring and correcting position information, facilitating the regulation of position control instructions and providing more I / O points.

[0103] It is worth noting that, as a preferred technical solution, the communication protocol between the pitch controller and the main drive includes but is not limited to one or a combination of CanOpen, Profibus, and RS485.

[0104] The pitch controller receives control instructions from the main controller through the above communication protocol and feeds back the actual state of the pitch to the main controller, thereby improving the control coordination of the system and reducing system communication failures.

[0105] It is worth noting that, as a preferred technical solution, the communication protocol between the master drive and the slave drive includes but is not limited to one or a combination of multi-axis bus, ETHcat, CanOpen, Profibus, and RS485.

[0106] The master drive sends speed limit values, current values, and control words to the slave drive via the communication protocol. The slave drive then uses the communication protocol to provide timely feedback on the slave drive status to the master drive. Multi-axis bus communication with a time of 1ms is preferred.

[0107] It is worth noting that it is preferred that the main drive circuit and the slave drive circuit can be selectively switched in the control software.

[0108] It is worth noting that, as a preferred technical solution, the pitch controller is a separate pitch controller, a pitch controller with a separate control card, or is built into the main drive.

[0109] This makes the optional installation locations and actual structures of the pitch controller more diverse, making it easier to adapt to a wider range of application scenarios.

[0110] Example 2

[0111] A control method for a wind turbine dual-drive electric pitch control system, comprising the following steps:

[0112] S1, the main controller sends the position control command to the main driver;

[0113] S2, the master driver receives the position control command, combines the actual position information and actual speed information of the master motor fed back by the master position and speed sensor to drive the master motor to work, and controls the slave driver to drive the slave motor to work;

[0114] S3, the main motor drives the main reducer to work, and the slave motor drives the slave reducer to work;

[0115] S4, the main position and speed sensor detects and outputs the actual position information and actual speed information of the main motor to the main driver;

[0116] S5. The main reducer drives the variable pitch bearing to work, and the slave reducer drives the variable pitch bearing to work.

[0117] It is worth noting that because the system operates dynamically, the flow of electrical signals is also dynamic, and there is feedback, so the above steps do not have only one order.

[0118] The main drive circuit consists of the master controller, main drive, main motor, main reducer, and pitch bearing. The slave drive circuit consists of the master controller, main drive (partially), slave drive, slave motor, slave reducer, and pitch bearing. These dual drive circuits distribute stress concentration on the main teeth, reducing the load on a single tooth. This effectively reduces severe wear and even fatigue damage on the main teeth, thereby improving turbine safety. Optimally, the master drive circuit and the slave drive circuit each share half of the main tooth stress.

[0119] As a preferred technical solution, a control method for a wind turbine dual-drive electric pitch control system is provided, wherein the master driver comprises a position controller, a speed controller, a main current controller, a main power converter, a main current sensor, and a position-speed signal conversion module connected in sequence, and the slave driver comprises a slave current controller, a slave power converter, and a slave current sensor;

[0120] Step S1 specifically includes the following steps:

[0121] K1, the main controller sends the position control instruction to the position controller;

[0122] Step S2 specifically includes the following steps:

[0123] K2, the position controller receives the position control command, combines the actual position information of the main motor fed back by the main position speed sensor and the position speed signal conversion module, and sends the speed command to the speed controller;

[0124] K3, the speed controller receives the speed command, combines the actual speed information of the main motor fed back by the main position speed sensor and the position speed signal conversion module, and sends the torque command to the main current controller and the slave current controller;

[0125] K4, the main current controller receives the torque command, combines the actual current information of the main motor output by the main current sensor, and sends an output signal to control the main power converter;

[0126] K5, the main power converter receives the output signal sent by the main current controller and outputs the current information after power conversion to the main current sensor;

[0127] K6, the main current sensor receives the current information output by the main power converter, detects the actual current information of the main motor and feeds the actual current information of the main motor back to the input end of the main current controller;

[0128] K7, the position and speed signal conversion module receives and converts the actual position information and actual speed information of the main motor fed back by the main position and speed sensor, and transmits the actual position information to the input end of the position controller and the actual speed information to the input end of the speed controller;

[0129] K8, receives the torque command from the current controller, combines it with the actual current information of the slave motor fed back from the current sensor, and sends an output signal to control the slave power converter;

[0130] K9, the slave power converter receives the output signal sent from the slave current controller, and outputs the current information after power conversion to the slave current sensor;

[0131] K10, receiving the current information output from the power converter from the current sensor, detecting the actual current information from the motor and feeding back the actual current information from the motor to the input end of the slave current controller;

[0132] Step S4 specifically includes the following steps:

[0133] K11, the main position and speed sensor detects and outputs the actual position information and actual speed information of the main motor to the position and speed signal conversion module.

[0134] It is worth noting that because the system operates dynamically, the flow of electrical signals is also dynamic, and there is feedback, so the above steps do not have only one order.

[0135] Position loop control is achieved by comparing the position control command given by the master controller with the actual position value of the main motor. Speed ​​loop control is achieved by comparing the speed command given by the position loop with the actual speed value of the main motor. Main current loop control is achieved by comparing the current command given by the speed loop with the actual current value of the main motor. The slave current controller achieves slave current loop control by comparing the received current command control (slave torque command) with the actual current value received by the slave motor. The slave motor drives the slave reducer and drives the blade bearing. This achieves torque synchronization of the dual-drive electric pitch system, reduces pitch bearing stress, reduces single tooth load, and improves the safety and reliability of the pitch system.

[0136] The aforementioned main solution of the present invention and its various alternatives may be freely combined to form multiple solutions, all of which are applicable and claimed by the present invention. Furthermore, the (non-conflicting) alternatives of the present invention may also be freely combined with each other and with other alternatives. After understanding the solutions of the present invention, those skilled in the art will readily appreciate, based on prior art and common knowledge, the various possible combinations, all of which are claimed by the present invention, and these are not exhaustive.

[0137] As described above, the present invention can be preferably implemented.

[0138] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Based on the technical essence of the present invention and within the spirit and principles of the present invention, any simple modification, equivalent replacement and improvement of the above embodiment shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A wind turbine dual-drive electric pitch control system, characterized in that: The system comprises a main controller, a main driver, a main motor, and a main position and speed sensor electrically connected in sequence; a main motor, a main reducer, and a pitch bearing mechanically connected in sequence; the main position and speed sensor is electrically connected to the main driver; and further comprises a slave driver, a slave motor, and a slave reducer; the main driver, the slave driver, and the slave motor are electrically connected in sequence; and the slave motor, the slave reducer, and the pitch bearing are mechanically connected in sequence; The master driver includes a position-speed signal conversion module and a position controller, a speed controller, a current controller, a main power converter, and a main current sensor electrically connected in sequence. The input end of the position-speed signal conversion module is connected to the output end of the main position-speed sensor, and the output end of the position-speed signal conversion module is electrically connected to the input end of the position controller and the input end of the speed controller, respectively. The slave driver includes a slave current controller, a slave power converter, and a slave current sensor electrically connected in sequence. The output end of the speed controller is electrically connected to the input end of the slave current controller, and the output end of the slave current sensor is electrically connected to the input end of the slave current controller and the slave motor, respectively. The slave driver also includes a speed limiter electrically connected to the output end of the position controller and the input end of the slave power converter, respectively. The master power converter and / or the slave power converter are PWM inverters.

2. A wind turbine dual-drive electric pitch control system according to claim 1, characterized in that: The main position and speed sensor is a rotary transformer.

3. A wind turbine dual-drive electric pitch control system according to claim 1, characterized in that: Also included is a slave position speed sensor electrically connected to the slave motor.

4. A wind turbine dual-drive electric pitch control system according to claim 3, characterized in that: The slave position and speed sensor is a rotary transformer.

5. A wind turbine dual-drive electric pitch control system according to any one of claims 1 to 4, characterized in that: It also includes a pitch controller, and the main controller, pitch controller, and position controller are electrically connected in sequence.

6. A control method for a wind turbine dual-drive electric pitch control system according to any one of items 1 to 5, characterized in that: The following steps are involved: S1, the main controller sends the position control command to the main driver; S2, the master driver receives the position control command, combines the actual position information and actual speed information of the master motor fed back by the master position and speed sensor to drive the master motor to work, and controls the slave driver to drive the slave motor to work; S3, the main motor drives the main reducer to work, and the slave motor drives the slave reducer to work; S4, the main position and speed sensor detects and outputs the actual position information and actual speed information of the main motor to the main driver; S5. The main reducer drives the variable pitch bearing to work, and the slave reducer drives the variable pitch bearing to work.

7. A control method for a wind turbine dual-drive electric pitch control system according to claim 6, characterized in that: The master driver includes a position controller, a speed controller, a master current controller, a master power converter, a master current sensor, and a position-speed signal conversion module connected in sequence, and the slave driver includes a slave current controller, a slave power converter, and a slave current sensor; Step S1 specifically includes the following steps: K1, the main controller sends the position control instruction to the position controller; Step S2 specifically includes the following steps: K2, the position controller receives the position control command, combines the actual position information of the main motor fed back by the main position speed sensor and the position speed signal conversion module, and sends the speed command to the speed controller; K3, the speed controller receives the speed command, combines the actual speed information of the main motor fed back by the main position speed sensor and the position speed signal conversion module, and sends the torque command to the main current controller and the slave current controller; K4, the main current controller receives the torque command, combines the actual current information of the main motor output by the main current sensor, and sends an output signal to control the main power converter; K5, the main power converter receives the output signal sent by the main current controller and outputs the current information after power conversion to the main current sensor; K6, the main current sensor receives the current information output by the main power converter, detects the actual current information of the main motor and feeds the actual current information of the main motor back to the input end of the main current controller; K7, the position and speed signal conversion module receives and converts the actual position information and actual speed information of the main motor fed back by the main position and speed sensor, and transmits the actual position information to the input end of the position controller and the actual speed information to the input end of the speed controller; K8, receives the torque command from the current controller, combines it with the actual current information of the slave motor fed back from the current sensor, and sends an output signal to control the slave power converter; K9, the slave power converter receives the output signal sent from the slave current controller, and outputs the current information after power conversion to the slave current sensor; K10, receiving the current information output from the power converter from the current sensor, detecting the actual current information from the motor and feeding back the actual current information from the motor to the input end of the slave current controller; Step S4 specifically includes the following steps: K11, the main position and speed sensor detects and outputs the actual position information and actual speed information of the main motor to the position and speed signal conversion module.

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