Wind turbine pitch control system and wind turbine generator

Abstract

A wind turbine pitch control system (10). The wind turbine pitch control system (10) comprises: a backup pitch control module (100), a switching module (200), and a primary pitch control module (300). When the primary pitch control module (300) fails, the switching module (200) is used for connecting a brake power output end (A1) of the backup pitch control module (100) to a motor side brake end (C1) of the primary pitch control module (300), and the switching module (200) is also used for connecting a motor power output end (A2) of the backup pitch control module (100) to a motor side power end (C2) of the primary pitch control module (300), so that the backup pitch control module (100) drives a motor (320) in the primary pitch control module (300) to control the position of blades. The wind turbine pitch control system (10) can drive the blades to continue grid-connected operation when the primary pitch control module (300) fails, thereby reducing the probability of blade jamming, improving safety performance of wind turbine generators, and further reducing power generation loss of the wind turbine generators. Further comprised is a wind turbine generator.

Description

A wind power pitch control system and a wind turbine generator set Technical Field

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

[0002] With the gradual maturation of wind power technology, high-power offshore turbines have become a new direction for the development of the wind power industry. As a safety component in wind turbine generators, the pitch system's performance directly affects the input power and safety of the turbine generator.

[0003] When a pitch control system malfunctions and causes blade jamming, it increases the safety risks of the wind turbine. Furthermore, for offshore wind turbines, due to the harsh marine environment, limited maintenance windows, and high costs of operation at sea, prolonged downtime results in significant power loss. Currently, when a pitch control system malfunction causes blade jamming, the turbine cannot feather back to a safe position, affecting overall turbine safety. On the other hand, a pitch control system malfunction prevents the wind turbine from continuing grid connection, leading to severe power generation losses.

[0004] Therefore, how to reduce the probability of blade jamming and power generation loss is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a wind turbine pitch control system and a wind turbine generator set to improve the safety performance of the wind turbine generator set and reduce the power generation loss of the wind turbine generator set.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] On one hand, the present invention provides a wind power pitch system, the wind power pitch system comprising: a backup pitch module, a switching module and a main pitch module;

[0008] The brake power output terminal of the backup pitch module is disconnected or connected to the motor-side brake terminal of the main pitch module through the switching module, and the motor power output terminal of the backup pitch module is disconnected or connected to the motor-side power terminal of the main pitch module through the switching module.

[0009] When the main pitch module fails, the switching module is used to connect the brake power output terminal of the backup pitch module to the motor-side brake terminal of the main pitch module. The switching module is also used to connect the motor power output terminal of the backup pitch module to the motor-side power terminal of the main pitch module, so that the backup pitch module drives the motor in the main pitch module to control the position of the blades.

[0010] Furthermore, both the main pitch module and the standby pitch module are connected to the control module; the first port of the switching module is connected to the brake power output terminal of the standby pitch module, and the second port of the switching module is connected to the motor-side brake terminal of the main pitch module.

[0011] The third port of the switching module is connected to the motor power output terminal of the backup pitch module, and the fourth port of the switching module is connected to the motor-side power terminal of the main pitch module.

[0012] When the main pitch module fails, the main pitch module sends a fault signal to the control module. Upon receiving the fault signal, the control module sends a switching command to the backup pitch module. Upon receiving the switching command, the backup pitch module controls the first port of the switching module to connect with the second port of the switching module, and controls the third port of the switching module to connect with the fourth port of the switching module.

[0013] Furthermore, the switching module includes a brake switching unit and a power switching unit, and the main pitch module includes a first driver and a motor;

[0014] The first driver is connected to the control module; the first brake power input terminal of the brake switching unit is connected to the brake power output terminal of the first driver, the second brake power input terminal of the brake switching unit is connected to the brake power output terminal of the spare pitch module, and the brake power output terminal of the brake switching unit is connected to the brake terminal of the motor.

[0015] The first motor power input terminal of the power switching unit is connected to the motor power output terminal of the first driver, the second motor power input terminal of the power switching unit is connected to the motor power output terminal of the backup pitch module, and the motor power output terminal of the power switching unit is connected to the power terminal of the motor.

[0016] When the first driver fails, the second brake power input terminal of the brake switching unit is connected to the brake power output terminal of the brake switching unit, and the second motor power input terminal of the power switching unit is connected to the motor power output terminal of the power switching unit.

[0017] Furthermore, the switching module also includes an encoder switching unit, and the main pitch module also includes a first encoder and a second encoder;

[0018] Both the first encoder and the second encoder are mounted on the motor. The output terminal of the first encoder is connected to the encoder signal input terminal of the first driver, the output terminal of the second encoder is connected to the input terminal of the encoder switching unit, and the output terminal of the encoder switching unit is connected to the encoder signal input terminal of the spare pitch module.

[0019] When the first encoder malfunctions, the input terminal of the encoder switching unit is connected to the output terminal of the encoder switching unit.

[0020] Furthermore, the backup pitch module includes a second driver; the second driver is connected to the control module; the brake power output terminal of the second driver is connected to the second brake power input terminal of the brake switching unit, the motor power output terminal of the second driver is connected to the second motor power input terminal of the power switching unit, and the encoder signal input terminal of the second driver is connected to the output terminal of the encoder switching unit.

[0021] Furthermore, the brake switching unit includes a first switch, the stationary contact of which is connected to the brake end of the motor;

[0022] When the first driver fails, the moving contact of the first switch closes with the brake power output terminal of the backup pitch module.

[0023] Furthermore, the power switching unit includes a second switch, the stationary contact of which is connected to the power end of the motor;

[0024] When the first driver fails, the moving contact of the second switch closes with the power output terminal of the backup pitch module.

[0025] Furthermore, the encoder switching unit includes a third switch, the stationary contact of which is connected to the encoder signal input terminal of the second driver;

[0026] When the first encoder in the main pitch module fails, the main pitch module with the failed first encoder is designated as the faulty main pitch module, and the moving contact of the third switch is closed with the output terminal of the second encoder in the faulty main pitch module.

[0027] Furthermore, the encoder switching unit includes a fourth switch, the stationary contact of which is connected to the output terminal of the second encoder;

[0028] When the first encoder in the main pitch module fails, the main pitch module with the failed first encoder is designated as the faulty main pitch module, and the moving contact of the fourth switch corresponding to the faulty main pitch module is closed with the encoder signal input terminal of the second driver.

[0029] Furthermore, the power supply terminals of both the first driver and the second driver are connected to the main power supply.

[0030] Furthermore, the main pitch module also includes a first energy storage device, and the standby pitch module also includes a second energy storage device; the first energy storage device is connected to the first driver, and the second energy storage device is connected to the second driver.

[0031] Furthermore, the first driver internally includes a first charging unit and a first discharging unit, and the second driver internally includes a second charging unit and a second discharging unit;

[0032] When the main power supply is normal, the DC bus inside the first driver charges the first energy storage device through the first charging unit, and the DC bus inside the second driver charges the second energy storage device through the second charging unit.

[0033] When the main power supply is abnormal, the first energy storage device provides energy to the DC bus inside the first driver through the first discharge unit, and the second energy storage device provides energy to the DC bus inside the second driver through the second discharge unit.

[0034] Furthermore, both the first charging unit and the second charging unit are BUCK circuits, both the first discharging unit and the second discharging unit are diodes, and both the first energy storage device and the second energy storage device are supercapacitors.

[0035] When the main power supply is normal, the BUCK circuit provides a constant charging current to the supercapacitor;

[0036] When the main power supply is abnormal and the DC bus voltage inside the driver is lower than the supercapacitor voltage, the supercapacitor provides energy to the DC bus inside the driver through the diode.

[0037] Furthermore, the control module is a PLC controller, and the backup pitch module and the main pitch module are connected to the PLC controller via bus communication.

[0038] On the other hand, the present invention also provides a wind turbine generator set, the wind turbine generator set including a wind power pitch system as described in any of the foregoing embodiments.

[0039] Compared with the prior art, the present invention has the following advantages:

[0040] This invention provides a wind turbine pitch control system and a wind turbine generator set, comprising: a standby pitch control module, a switching module, and a main pitch control module. When the main pitch control module fails, the switching module connects the brake power output terminal of the standby pitch control module to the motor-side brake terminal of the main pitch control module. The switching module also connects the motor power output terminal of the standby pitch control module to the motor-side power terminal of the main pitch control module. In this situation, the standby pitch control module can provide brake power and motor power to the motor in the failed main pitch control module to drive the motor and control the blade position, allowing the blades to continue operating in grid-connected mode. This avoids the safety risks caused by blade jamming due to a main pitch control module failure and the power generation loss due to downtime. Attached Figure Description

[0041] To more clearly illustrate the technical solutions of the present invention, the accompanying drawings used in the present invention will be briefly introduced below. It should be understood that the following drawings only show some technical solutions of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0042] Figure 1 is one of the structural schematic diagrams of a wind power pitch system provided by the present invention;

[0043] Figure 2 is a second structural schematic diagram of a wind power pitch system provided by the present invention;

[0044] Figure 3 is a third structural schematic diagram of a wind power pitch system provided by the present invention;

[0045] Figure 4 is one of the schematic diagrams of a wind power pitch system provided by the present invention;

[0046] Figure 5 is a second schematic diagram of a wind power pitch system provided by the present invention;

[0047] Figure 6 is a fourth structural schematic diagram of a wind power pitch system provided by the present invention.

[0048] Icons: 10-Wind power pitch system; 100-Standby pitch module; 110-Second drive; 120-Second energy storage device; 200-Switching module; 210-Brake switching unit; 220-Power switching unit; 230-Encoder switching unit; 300-Main pitch module; 310-First drive; 320-Motor; 330-First encoder; 340-Second encoder; 350-First energy storage device. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described technical solutions are only a part of the technical solutions of this invention, not all of them. The components of the technical solutions of this invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the technical solutions of this invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected technical solutions of the invention. All other technical solutions obtained by those skilled in the art based on the technical solutions of this invention without inventive effort are within the scope of protection of this invention.

[0050] As mentioned in the background section, when a pitch control system malfunction causes blade jamming, the blades cannot feather back to a safe position, affecting the overall safety of the turbine. Furthermore, a pitch control system malfunction prevents the wind turbine from continuing grid-connected operation, resulting in significant power generation losses. Therefore, reducing the probability of blade jamming and power generation losses is a technical problem that urgently needs to be solved by those skilled in the art.

[0051] To address the aforementioned technical issues, please refer to Figure 1. This embodiment provides a wind power pitch system 10, including: a backup pitch module 100, a switching module 200, and a main pitch module 300. When the main pitch module 300 is functioning normally, it drives the wind turbine blades.

[0052] The brake power output terminal A1 of the standby pitch module 100 is disconnected or connected to the motor-side brake terminal C1 of the main pitch module 300 through the switching module 200, and the motor power output terminal A2 of the standby pitch module 100 is disconnected or connected to the motor-side power terminal C2 of the main pitch module 300 through the switching module 200.

[0053] When the main pitch module 300 fails, the switching module 200 is used to connect the brake power output terminal A1 of the standby pitch module 100 to the motor-side brake terminal C1 of the main pitch module 300. The switching module 200 is also used to connect the motor power output terminal A2 of the standby pitch module 100 to the motor-side power terminal C2 of the main pitch module 300.

[0054] At this time, the backup pitch module 100 can provide brake power and motor power to the motor in the main pitch module 300 that has failed, so as to drive the motor to control the blade position and avoid the safety risks caused by blade jamming due to the failure of the main pitch module 300 and the loss of power generation caused by shutdown.

[0055] Specifically, in this embodiment of the invention, both the main pitch module 300 and the standby pitch module 100 are connected to the control module. The first port B1 of the switching module 200 is connected to the brake power output terminal A1 of the standby pitch module 100, and the second port B2 of the switching module 200 is connected to the motor-side brake terminal C1 of the main pitch module 300. The third port B3 of the switching module 200 is connected to the motor power output terminal A2 of the standby pitch module 100, and the fourth port B4 of the switching module 200 is connected to the motor-side power terminal C2 of the main pitch module 300.

[0056] When the main pitch module 300 malfunctions, it sends a fault signal to the control module. Upon receiving the fault signal, the control module sends a switching command to the standby pitch module 100. When the standby pitch module 100 receives the switching command, it connects the first port B1 of the switching module 200 to the second port B2, and the third port B3 of the switching module 200 to the fourth port B4.

[0057] In one alternative implementation, referring to FIG2, the switching module 200 includes a brake switching unit 210 and a power switching unit 220, and the main pitch module 300 includes a first driver 310 and a motor 320.

[0058] The first driver 310 is connected to the control module. The first brake power input terminal D1 of the brake switching unit 210 is connected to the brake power output terminal E1 of the first driver 310, the second brake power input terminal D2 of the brake switching unit 210 is connected to the brake power output terminal A1 of the spare pitch module 100, and the brake power output terminal D3 of the brake switching unit 210 is connected to the brake terminal G1 of the motor 320.

[0059] The first motor power input terminal F1 of the power switching unit 220 is connected to the motor power output terminal E2 of the first driver 310, the second motor power input terminal F2 of the power switching unit 220 is connected to the motor power output terminal A2 of the spare pitch module 100, and the motor power output terminal F3 of the power switching unit 220 is connected to the power terminal G2 of the motor 320.

[0060] When the first driver 310 in the main pitch module 300 fails, the first driver 310 will be unable to provide brake power and motor power to the motor 320. The first driver 310 sends a fault information to the control module. After receiving the fault information, the control module sends a switching command to the backup pitch module 100, ordering the backup pitch module 100 to take over the blades corresponding to the faulty first driver 310.

[0061] At this time, the second brake power input terminal D2 of the brake switching unit 210 is connected to the brake power output terminal D3 of the brake switching unit 210, which is equivalent to the backup pitch module 100 providing brake power to the motor 320 in the faulty main pitch module 300. The second motor power input terminal F2 of the power switching unit 220 is connected to the motor power output terminal F3 of the power switching unit 220, which is equivalent to the backup pitch module 100 providing motor power to the motor 320 in the faulty main pitch module 300. That is, the backup pitch module 100 takes over the faulty first drive 310 and provides brake power and motor power to the corresponding motor 320 so that the motor 320 can drive the corresponding blade normally.

[0062] Furthermore, the switching module 200 also includes an encoder switching unit 230, and the main pitch module 300 also includes a first encoder 330 and a second encoder 340.

[0063] The first encoder 330 and the second encoder 340 are both mounted on the motor 320. The output of the first encoder 330 is connected to the encoder signal input E3 of the first driver 310. The output of the second encoder 340 is connected to the input of the encoder switching unit 230, and the output of the encoder switching unit 230 is connected to the encoder signal input A3 of the spare pitch module 100.

[0064] In this embodiment of the invention, the first encoder 330 is the main encoder, and the second encoder 340 is the backup encoder. When the first encoder 330 is working properly, the position information of the motor 320 is provided to the first driver 310 by the first encoder 330.

[0065] When the first encoder 330 fails, the input terminal of the encoder switching unit 230 is connected to the output terminal of the encoder switching unit 230, that is, the position information of the motor 320 is provided to the backup pitch module 100 by the second encoder 340.

[0066] Further, referring to Figure 3, the backup pitch module 100 includes a second driver 110. The second driver 110 is connected to the control module. The brake power output terminal A1 of the second driver 110 is connected to the second brake power input terminal D2 of the brake switching unit 210, the motor power output terminal A2 of the second driver 110 is connected to the second motor power input terminal F2 of the power switching unit 220, and the encoder signal input terminal A3 of the second driver 110 is connected to the output terminal of the encoder switching unit 230.

[0067] It should be noted that the control signals of the brake switching unit 210, the power switching unit 220, and the encoder switching unit 230 all have interlocking logic to ensure that a paddle motor 320 has only one brake power input and one motor power input, and that the encoder signal input terminal A3 of the second driver 110 has only one encoder signal input.

[0068] Furthermore, the present invention does not limit the number of main pitch modules 300, that is, the number of main pitch modules 300 can be one or more.

[0069] To better understand the connection relationship and working principle between the standby pitch module 100 and the multiple main pitch modules 300, please refer to Figure 4. Assuming that the wind power pitch system 10 includes three main pitch modules 300, the number of brake switching units 210 and power switching units 220 in the switching module 200 are both three, and the number of encoder switching units 230 is one.

[0070] In this configuration, the control module is the master station, and the second drive and the three first drives are all slave stations. The communication topology between the master station and the slave stations is a daisy chain. Optionally, the control module can be a PLC controller, which is connected to the second drive in the standby pitch module and the first drive in the three main pitch modules via bus communication.

[0071] The brake switching unit 210 includes a first switch, the stationary contact of which is connected to the brake terminal of the motor. The power switching unit 220 includes a second switch, the stationary contact of which is connected to the power terminal of the motor. The encoder switching unit 230 includes a third switch, the stationary contact of which is connected to the encoder signal input terminal of the second driver.

[0072] During normal operation, the control module issues position commands to the first actuators A, B, and C. The moving contact of the first switch in each brake switching unit 210 is closed with the brake power output terminal of the corresponding first actuator, and the moving contact of the second switch in each power switching unit 220 is closed with the motor power output terminal of the corresponding first actuator. At this time, the first actuator in each main pitch module provides brake power and motor power to the corresponding motor, enabling the motor to drive the blades. The first encoder in each main pitch module feeds back the real-time blade position information to the corresponding first actuator, which then feeds back the blade position information to the control module. The control module adjusts the position commands in real time based on the position information of the three blades fed back by the three first actuators.

[0073] When the first encoder A malfunctions, the corresponding first switch K 1A The moving contact of the first driver A is disconnected from the brake power output terminal, and the corresponding second switch K... 2AThe moving contact of the first driver A is disconnected from the motor power output terminal, meaning the first driver A stops both motor power output and brake power output. Furthermore, the first driver A feeds back fault information to the control module, which then sends a switching command to the second driver upon receiving the fault information.

[0074] The switching command includes the serial number of the faulty main pitch module and the position information of the corresponding blade before the fault. The second drive in the backup pitch module can then determine which main pitch module failed and the position information of the blade driven by the faulty module based on the switching command. This allows the second drive to take over from the first drive in the faulty main pitch module, ensuring continuous blade operation.

[0075] In other words, when the first encoder A malfunctions, the second driver, based on the switching command sent by the control module, controls the moving contact of the third switch to close with the output terminal A of the second encoder A in the faulty main pitch module. This is equivalent to the second driver starting to receive feedback signals from the second encoder A. The corresponding first switch K... 1A The moving contact of the second actuator closes with the brake power output terminal of the second actuator, corresponding to the second switch K. 2A When the moving contact of the second driver closes with the motor power output terminal of the second driver, it is equivalent to the second driver replacing the first driver A to drive motor A. The braking power and motor power of motor A are both provided by the second driver.

[0076] Combining the above operations, the faulty shaft blade can be restored to normal operation, and the faulty shaft blade will continue to run under the control of the second driver. During regular maintenance, the faults of the first driver A and the first encoder A will be checked and addressed. After the faults are addressed, the control module will clear the latched fault information so that the first driver A can drive the corresponding blade again.

[0077] Since there are three main pitch control modules, the encoder switching unit 230 can be either the single-pole three-throw switch K3 shown in Figure 4, or the three fourth switches K shown in Figure 5. 4A K 4B K 4C .

[0078] Specifically, referring to Figure 5, the encoder switching unit 230 includes a fourth switch, and the stationary contact of the fourth switch is connected to the output terminal of the second encoder. Assuming there are three main pitch modules, the number of fourth switches is also three (i.e., K). 4A K 4B K 4C Furthermore, the stationary contact of each fourth switch is connected to the output terminal of the corresponding second encoder.

[0079] When the first encoder A in the main pitch module fails, the main pitch module with the failed first encoder A is designated as the faulty main pitch module. The fourth switch K corresponds to the faulty main pitch module. 4A The moving contact of the first driver closes with the encoder signal input terminal of the second driver. At this time, the second driver takes over from the first driver A to receive the position information fed back by the second encoder A.

[0080] Further, referring to Figure 6, the power supply terminals of both the first driver 310 and the second driver 110 are connected to the main power supply. To avoid blade jamming due to main power supply malfunction, in this embodiment of the invention, the main pitch module 300 further includes a first energy storage device 350, and the backup pitch module 100 further includes a second energy storage device 120. The first energy storage device 350 is connected to the first driver 310, and the second energy storage device 120 is connected to the second driver 110.

[0081] In this embodiment of the invention, the first driver 310 includes a first charging unit and a first discharging unit, and the second driver 110 includes a second charging unit and a second discharging unit. When the main power supply is normal, the DC bus inside the first driver 310 charges the first energy storage device 350 through the first charging unit, and the DC bus inside the second driver 110 charges the second energy storage device 120 through the second charging unit.

[0082] When the main power supply fails, the first energy storage device 350 provides energy to the DC bus inside the first driver 310 through the first discharge unit, and the second energy storage device 120 provides energy to the DC bus inside the second driver 110 through the second discharge unit. This ensures that each driver has dual power supplies as redundant inputs, and can feather the blades to a safe position even if a single power supply is lost, further improving the safety performance of the wind turbine generator set.

[0083] Optionally, the first discharge unit and the second discharge unit can be diodes, IGBTs or MOSFETs, and the first energy storage device 350 can be a supercapacitor or a battery.

[0084] In this embodiment of the invention, both the first charging unit and the second charging unit are BUCK circuits, both the first discharging unit and the second discharging unit are diodes, and both the first energy storage device 350 and the second energy storage device 120 are supercapacitors.

[0085] When the main power supply is normal, the BUCK circuit provides a constant charging current to the supercapacitor.

[0086] When the main power supply is abnormal and the DC bus voltage inside the driver is lower than the supercapacitor voltage, the supercapacitor provides energy to the DC bus inside the driver through the diode.

[0087] Furthermore, the main power supply can be the power grid, which is connected to the three-phase AC input terminals of the second driver 110 and the first driver 310, respectively. When the power grid experiences an abnormal power outage, the supercapacitor provides energy to the DC bus inside the driver through diodes, preventing blade jamming and subsequent shutdown.

[0088] In addition, embodiments of the present invention also provide a wind turbine generator set, which includes a wind power pitch system 10 as described in any of the foregoing embodiments.

[0089] In summary, this invention provides a wind power pitch control system and a wind turbine generator set. The wind power pitch control system includes a standby pitch control module, a switching module, and a main pitch control module. Specifically, the brake power output terminal of the standby pitch control module is disconnected from or connected to the motor-side brake terminal of the main pitch control module via the switching module, and the motor power output terminal of the standby pitch control module is disconnected from or connected to the motor-side power terminal of the main pitch control module via the switching module.

[0090] When the main pitch module fails, the switching module connects the brake power output terminal of the standby pitch module to the motor-side brake terminal of the main pitch module. The switching module also connects the motor power output terminal of the standby pitch module to the motor-side power terminal of the main pitch module. In this situation, the standby pitch module can provide brake power and motor power to the motor in the failed main pitch module to drive the motor and control the blade position, allowing the blades to continue operating in grid-connected mode. This avoids the safety risks caused by blade jamming due to the main pitch module failure and the power generation loss due to downtime.

[0091] In addition, by setting up a first energy storage device and a second energy storage device, both the main pitch module and the backup pitch module have dual power supplies as redundant inputs. In the event of loss of main power, the blades can be feathered to a safe position, further improving the safety performance of the wind turbine generator set.

[0092] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of the present invention is defined by the appended claims rather than the foregoing description, and therefore all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A wind power pitch control system, characterized in that, The wind power pitch system includes: a backup pitch module, a switching module, and a main pitch module; The brake power output terminal of the backup pitch module is disconnected or connected to the motor-side brake terminal of the main pitch module through the switching module, and the motor power output terminal of the backup pitch module is disconnected or connected to the motor-side power terminal of the main pitch module through the switching module. When the main pitch module fails, the switching module is used to connect the brake power output terminal of the backup pitch module to the motor-side brake terminal of the main pitch module. The switching module is also used to connect the motor power output terminal of the backup pitch module to the motor-side power terminal of the main pitch module, so that the backup pitch module drives the motor in the main pitch module to control the position of the blades.

2. The wind power pitch control system according to claim 1, characterized in that, Both the main pitch module and the backup pitch module are connected to the control module. The first port of the switching module is connected to the brake power output terminal of the backup pitch module, and the second port of the switching module is connected to the motor-side brake terminal of the main pitch module. The third port of the switching module is connected to the motor power output terminal of the backup pitch module, and the fourth port of the switching module is connected to the motor-side power terminal of the main pitch module. When the main pitch module fails, the main pitch module sends a fault signal to the control module. Upon receiving the fault signal, the control module sends a switching command to the backup pitch module. Upon receiving the switching command, the backup pitch module controls the first port of the switching module to connect with the second port of the switching module, and controls the third port of the switching module to connect with the fourth port of the switching module.

3. The wind power pitch control system according to claim 2, characterized in that, The switching module includes a brake switching unit and a power switching unit, and the main pitch module includes a first driver and a motor. The first driver is connected to the control module; the first brake power input terminal of the brake switching unit is connected to the brake power output terminal of the first driver, the second brake power input terminal of the brake switching unit is connected to the brake power output terminal of the spare pitch module, and the brake power output terminal of the brake switching unit is connected to the brake terminal of the motor. The first motor power input terminal of the power switching unit is connected to the motor power output terminal of the first driver, the second motor power input terminal of the power switching unit is connected to the motor power output terminal of the backup pitch module, and the motor power output terminal of the power switching unit is connected to the power terminal of the motor. When the first driver fails, the second brake power input terminal of the brake switching unit is connected to the brake power output terminal of the brake switching unit, and the second motor power input terminal of the power switching unit is connected to the motor power output terminal of the power switching unit.

4. The wind power pitch control system according to claim 3, characterized in that, The switching module further includes an encoder switching unit, and the main pitch module further includes a first encoder and a second encoder. Both the first encoder and the second encoder are mounted on the motor. The output terminal of the first encoder is connected to the encoder signal input terminal of the first driver, the output terminal of the second encoder is connected to the input terminal of the encoder switching unit, and the output terminal of the encoder switching unit is connected to the encoder signal input terminal of the spare pitch module. When the first encoder malfunctions, the input terminal of the encoder switching unit is connected to the output terminal of the encoder switching unit.

5. The wind power pitch control system according to claim 4, characterized in that, The backup pitch module includes a second driver; The second driver is connected to the control module; the brake power output terminal of the second driver is connected to the second brake power input terminal of the brake switching unit, the motor power output terminal of the second driver is connected to the second motor power input terminal of the power switching unit, and the encoder signal input terminal of the second driver is connected to the output terminal of the encoder switching unit.

6. The wind power pitch control system according to claim 3, characterized in that, The brake switching unit includes a first switch, and the stationary contact of the first switch is connected to the brake end of the motor. When the first driver fails, the moving contact of the first switch closes with the brake power output terminal of the backup pitch module.

7. The wind power pitch control system according to claim 3, characterized in that, The power switching unit includes a second switch, and the stationary contact of the second switch is connected to the power end of the motor. When the first driver fails, the moving contact of the second switch closes with the power output terminal of the backup pitch module.

8. The wind power pitch control system according to claim 5, characterized in that, The encoder switching unit includes a third switch, the stationary contact of which is connected to the encoder signal input terminal of the second driver. When the first encoder in the main pitch module fails, the main pitch module with the failed first encoder is designated as the faulty main pitch module, and the moving contact of the third switch is closed with the output terminal of the second encoder in the faulty main pitch module.

9. The wind power pitch control system according to claim 5, characterized in that, The encoder switching unit includes a fourth switch, and the stationary contact of the fourth switch is connected to the output terminal of the second encoder. When the first encoder in the main pitch module fails, the main pitch module with the failed first encoder is designated as the faulty main pitch module, and the moving contact of the fourth switch corresponding to the faulty main pitch module is closed with the encoder signal input terminal of the second driver.

10. The wind power pitch control system according to claim 5, characterized in that, The power supply terminals of both the first driver and the second driver are connected to the main power supply.

11. The wind power pitch system according to claim 10, characterized in that, The main pitch module further includes a first energy storage device, and the standby pitch module further includes a second energy storage device; the first energy storage device is connected to the first driver, and the second energy storage device is connected to the second driver.

12. The wind power pitch system according to claim 11, characterized in that, The first driver includes a first charging unit and a first discharging unit, and the second driver includes a second charging unit and a second discharging unit. When the main power supply is normal, the DC bus inside the first driver charges the first energy storage device through the first charging unit, and the DC bus inside the second driver charges the second energy storage device through the second charging unit. When the main power supply is abnormal, the first energy storage device provides energy to the DC bus inside the first driver through the first discharge unit, and the second energy storage device provides energy to the DC bus inside the second driver through the second discharge unit.

13. The wind power pitch system according to claim 12, characterized in that, Both the first charging unit and the second charging unit are BUCK circuits, both the first discharging unit and the second discharging unit are diodes, and both the first energy storage device and the second energy storage device are supercapacitors. When the main power supply is normal, the BUCK circuit provides a constant charging current to the supercapacitor; When the main power supply is abnormal and the DC bus voltage inside the driver is lower than the supercapacitor voltage, the supercapacitor provides energy to the DC bus inside the driver through the diode.

14. The wind power pitch system according to claim 2, characterized in that, The control module is a PLC controller, and the backup pitch module and the main pitch module are connected to the PLC controller via bus communication.

15. A wind turbine generator set, characterized in that, The wind turbine generator set includes the wind power pitch system as described in any one of claims 1-14.

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