A method for emergency safety control of wind turbine generator set

Abstract

The present invention provides an emergency safety control method for a wind turbine generator set, which belongs to the technical field of wind turbine generator sets and solves the problem in the prior art that a wind turbine generator set lacks a sufficiently effective emergency shutdown control method when facing an emergency situation. The method comprises: when entering an emergency state, a coordinated control mode among a variable pitch system, a yaw system and a brake system is adopted to realize an emergency shutdown operation; hardware-level loops of the variable pitch system, the yaw system and the brake system in the wind turbine generator set adopt independent control modes; during the emergency shutdown operation, a software-level linkage control process is performed in a progressive manner in the order of the variable pitch system, the yaw system and the brake system, that is, whether the control process of the previous system is successful or not determines whether the control process of the next system is started; the present invention can realize the emergency shutdown effect of the wind turbine generator set, and can also shut down safely under extreme circumstances, thereby greatly reducing the risk of serious accidents of the wind turbine generator set.

Description

Technical Field

[0001] The invention belongs to the technical field of wind turbine generator sets, is applied to the safe shutdown process of wind turbine generator sets in emergency situations, and specifically is an emergency safety control method for wind turbine generator sets. Background Art

[0002] With the development of wind power technology, wind power equipment has been put into operation on a large scale, and the number of wind turbines has continued to increase; however, with the increase in the service life of the equipment, the potential safety hazards caused by the aging of the equipment components have become more and more prominent, especially the problem of overspeed caused by the failure of the wind turbine to retract its blades; this problem will further lead to serious accidents such as speeding and overturning of the unit. Therefore, this field now has higher requirements for the safety of the unit control system.

[0003] In the prior art, the control logic design when the unit is shut down is: if the normal retraction fails, the main control system will switch to the emergency retraction state after detecting the retraction timeout; the main control system sends an emergency retraction command to the variable pitch system, so that the variable pitch system switches to the backup power circuit to complete the retraction process. However, once the backup power circuit fails to retract the pitch, the entire wind turbine generator set is out of control. At this time, the blades may stay at a small angle and still absorb wind energy with a larger windward surface.

[0004] At the same time, when the wind turbine generator set sends an overspeed fault, the safety chain will be disconnected, the yaw system in the prior art will not be able to operate at this moment, and the brake system will be immediately activated at the same time; under high speed conditions, when the brake system is activated, it will bring a great impact to the wind turbine generator set, and it is difficult to achieve the desired effect of braking; and the friction between the brake pad and the high-speed shaft will produce hot sparks, which can easily ignite flammable materials such as the cover. In summary, the control logic and methods used in the prior art when facing emergency situations are defective and insufficient, and serious accidents such as speeding, burning and reversing are inevitable, resulting in significant economic losses. Summary of the invention

[0005] The purpose of the present invention is to provide a sufficiently safe method for the control process of a wind turbine generator set under emergency conditions. The greatest feature of this method is the coordinated control of the variable pitch system, yaw system and brake system of the wind turbine generator set. The control logics are independent of each other, but the control process is linked and progressive. The present invention can achieve the emergency shutdown effect of the wind turbine generator set, ensuring that it can be safely shut down even in extreme situations such as failure of the variable pitch backup power supply retraction circuit, thereby greatly reducing the risk of serious accidents of the wind turbine generator set.

[0006] The present invention adopts the following technical solutions to achieve the purpose:

[0007] An emergency safety control method for a wind turbine generator set, when the wind turbine generator set enters an emergency state, a coordinated control method among a variable pitch system, a yaw system and a brake system is adopted to realize an emergency shutdown operation; in the emergency state, the hardware-level loops of the variable pitch system, the yaw system and the brake system in the wind turbine generator set adopt independent control modes and are not affected by the mutual influence of the hardware connection relationship; during the emergency shutdown operation, a software-level linkage control process is performed in a progressive manner in the order of the variable pitch system, the yaw system and the brake system, that is, whether the control process of the previous system is successful or not determines whether the control process of the next system is started.

[0008] Furthermore, the coordinated control method and progressive software-level linkage control process among the pitch system, yaw system and brake system are as follows: when an emergency occurs, the main control system of the wind turbine performs the pitch retracting operation through the backup power supply circuit of the pitch system; if there is a problem with the backup power supply circuit, the main control system switches the control command and performs the pitch retracting operation through the AC power supply circuit of the pitch system.

[0009] Furthermore, when an emergency occurs, the main control system issues an emergency shutdown control command to control the pitch system to perform a pitch retracting operation; within the specified time after the emergency shutdown control command is issued, if the wind turbine generator speed has not dropped to a safe speed range, the main control system performs an emergency yaw operation through the yaw system to make the wind turbine yaw away from the main wind direction; during the emergency yaw process, the generator speed continues to drop. When the generator speed drops to a safe speed range, the main control system performs a main shaft brake operation through the brake system to lock the flywheel and stop the emergency yaw operation at the same time, thereby realizing the entire process of the wind turbine emergency shutdown operation.

[0010] Preferably, the specific control process logic of the pitch retraction operation performed by the pitch control system is as follows: when an emergency occurs, the main control system first issues a normal pitch retraction command, and performs the pitch retraction operation through the AC power circuit of the pitch control system; if the blades of the wind turbine set are not received at the specified position within the first time, the main control system issues an emergency pitch retraction command, and performs the pitch retraction operation through the backup power circuit of the pitch control system.

[0011] Preferably, after the main control system issues an emergency propeller retraction command, the main control system detects the propeller retraction operation status through the variable pitch system; after the command is issued and continues for a second time, if it is detected that at least one blade has not been retracted to the limit switch position, and the pitch angle of the blade is less than 70 degrees, the main control system sets the emergency propeller retraction command and performs the propeller retraction operation again through the AC power supply circuit of the variable pitch system.

[0012] Preferably, the specific process logic of the emergency yaw operation performed by the yaw system is: when the main control system issues an emergency shutdown control command, the timing starts at the same time. After the third time is reached, if the main control system detects that the generator speed of the wind turbine is still greater than the safe speed range, the yaw system performs an emergency yaw operation to make the wind turbine start to yaw.

[0013] Preferably, the yaw direction of the wind turbine is away from the main wind direction. If the deviation angle between the cabin direction of the current wind turbine and the main wind direction is less than 0 degrees, the yaw direction is counterclockwise; if the deviation angle between the cabin direction and the main wind direction is greater than 0 degrees, the yaw direction is clockwise; while the emergency yaw operation is in progress, if the main control system detects that the generator speed of the wind turbine is reduced to a safe speed range, the emergency yaw operation is stopped.

[0014] Preferably, the specific process logic of the main shaft braking operation performed by the braking system is: when the main control system issues an emergency shutdown control command, the main control system continuously detects the generator speed of the wind turbine set; when the emergency shutdown control command is issued, if the generator speed is higher than the safe speed range, the main control system will not activate the braking system except through manual braking and human intervention by pressing the emergency button; if the main control system detects that the generator speed is reduced to within the safe speed range, the main control system will activate the braking system and perform the main shaft braking operation until the wind turbine set completes the emergency shutdown process.

[0015] In summary, due to the adoption of this technical solution, the beneficial effects of the present invention are as follows:

[0016] The method of the present invention coordinates and controls the variable pitch system, yaw system and brake system of the wind turbine generator set in an emergency situation, thereby achieving an emergency shutdown effect of the wind turbine generator set; through the linkage control between the various systems, the wind turbine generator set can ensure shutdown in an emergency situation, and will not be completely out of control, thereby improving the safety of the unit. In the most extreme cases, such as failure of the backup power supply retracting circuit for variable pitch, under the coordinated linkage of the method of the present invention, the various systems cooperate to operate, and the unit achieves a safe shutdown process, which can reduce the risk of serious accidents such as speeding and tower burning and tower collapse in the wind turbine generator set. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the emergency safety control logic diagram of the method of the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Example

[0021] An emergency safety control method for a wind turbine generator set. The method mainly involves the control process of a variable pitch system, a yaw system and a brake system in the wind turbine generator set. This embodiment will explain the method content in detail.

[0022] When a wind turbine enters an emergency state, a coordinated control method is adopted among the pitch system, yaw system and brake system to achieve emergency shutdown operation; in the emergency state, the hardware-level circuits of the pitch system, yaw system and brake system in the wind turbine adopt independent control modes and are not affected by the mutual influence of hardware connection relationships; during the emergency shutdown operation, the software-level linkage control process is performed in a progressive manner in the order of the pitch system, yaw system and brake system, that is, the success or failure of the control process of the previous system determines whether the control process of the next system is started.

[0023] The implementation of the method of this embodiment requires consideration of both hardware and software design. For new wind turbine hardware, it can be directly designed to meet the requirement that the hardware-level loops of the pitch system, yaw system and brake system adopt independent control modes. However, for the hardware-level loops of traditional wind turbines, they have the following characteristics:

[0024] 1. If the safety chain is disconnected, the brake system will be immediately activated;

[0025] 2. If the safety chain is disconnected, the control circuit of the yaw system will be disconnected at the same time.

[0026] Therefore, when applying the method of this embodiment, it is necessary to improve the hardware-level circuit of the traditional wind turbine set so that the pitch system, yaw system and brake system therein become independent control modes and are not affected by the mutual influence of the hardware connection relationship; the improvement method includes: after the safety chain is disconnected, the brake system will not be put into operation at the same time; the specific improvement operation is: in the traditional wind turbine set, a specific node in the safety chain circuit is short-circuited, and the specific node is the node where the safety chain circuit is connected in series with the brake circuit.

[0027] At the same time, the improvement method also includes: after the safety chain is disconnected, the yaw system still operates normally; the specific improvement operation is: in the traditional wind turbine, a relay is added to the safety chain circuit, and the relay independently controls the circuit of the yaw system.

[0028] The following content is the main content of the method of this embodiment, involving the software control logic process, the coordinated control method among the pitch system, the yaw system and the brake system, and the progressive software-level linkage control process, specifically: when an emergency occurs, the main control system of the wind turbine performs the pitch retraction operation through the backup power supply circuit of the pitch system; if there is a problem with the backup power supply circuit, if no operation is performed at this time, the emergency pitch retraction will fail, so the main control system switches the control command and performs the pitch retraction operation through the AC power supply circuit of the pitch system. At the same time, within the specified time after the emergency shutdown control command is issued, if the speed of the wind turbine generator has not dropped to the safe speed range, the main control system performs an emergency yaw operation through the yaw system to make the wind turbine yaw away from the main wind direction; during the emergency yaw process, the generator speed continues to drop. When the generator speed drops to the safe speed range, the main control system performs the main shaft brake operation through the brake system to lock the flywheel and stop the emergency yaw operation at the same time, realizing the whole process of the emergency shutdown operation of the wind turbine. For the specific content judgment flow of the whole process, please refer to Figure 1 An example is given and described in detail in this embodiment as follows.

[0029] In this embodiment, the specific control process logic of the pitch retraction operation performed by the pitch control system is as follows: when an emergency occurs, the main control system first issues a normal pitch retraction command, and performs the pitch retraction operation through the AC power circuit of the pitch control system; if the blades of the wind turbine set are not received at the specified position within the specified first time, the main control system issues an emergency pitch retraction command, and performs the pitch retraction operation through the backup power circuit of the pitch control system.

[0030] Immediately afterwards, after the main control system issues the emergency propeller retraction command, the main control system detects the propeller retraction operation status through the variable pitch system; after the command is issued and continues for the specified second time, if it is detected that at least one propeller blade has not been retracted to the limit switch position, and the pitch angle of the propeller blade is less than 70 degrees, the main control system sets the emergency propeller retraction command and retracts the propellers again through the AC power supply circuit of the variable pitch system.

[0031] In this embodiment, the specific process logic of the emergency yaw operation performed by the yaw system is: the wind turbine enters the emergency shutdown state, the main control system issues an emergency shutdown control command, and starts timing at the same time. When the specified third time is reached, if the main control system detects that the generator speed of the wind turbine is still greater than the safe speed range, the yaw system performs an emergency yaw operation to make the wind turbine start to yaw.

[0032] The yaw direction of the wind turbine is away from the main wind direction. If the deviation angle between the nacelle direction of the current wind turbine and the main wind direction is less than 0 degrees, the yaw direction is counterclockwise; if the deviation angle between the nacelle direction and the main wind direction is greater than 0 degrees, the yaw direction is clockwise; while the emergency yaw operation is in progress, if the main control system detects that the generator speed of the wind turbine is reduced to a safe speed range, the emergency yaw operation will be stopped.

[0033] In this embodiment, the specific process logic of the main shaft braking operation performed by the braking system is: when the wind turbine triggers an emergency shutdown, the main control system issues an emergency shutdown control command and continuously detects the generator speed of the wind turbine; when the emergency shutdown control command is issued, if the generator speed is higher than the safe speed range, the main control system will not immediately activate the braking system except through manual braking and human intervention by pressing the emergency button; only when the main control system detects that the generator speed is reduced to within the safe speed range, will it activate the braking system and perform the main shaft braking operation until the wind turbine completes the emergency shutdown process.

Claims

1. An emergency safety control method for a wind turbine generator set, characterized in that: When the wind turbine enters the emergency state, the coordinated control method among the variable pitch system, yaw system and brake system is adopted to realize the emergency shutdown operation; in the emergency state, the hardware-level loops of the variable pitch system, yaw system and brake system in the wind turbine adopt independent control modes, which are not affected by the mutual influence of the hardware connection relationship; during the emergency shutdown operation, the software-level linkage control process is carried out in a progressive manner in the order of the variable pitch system, yaw system and brake system, that is, the success or failure of the control process of the previous system determines whether the control process of the next system is started; The coordinated control method and progressive software-level linkage control process among the pitch system, yaw system and brake system are as follows: when an emergency occurs, the main control system of the wind turbine retracts the pitch through the backup power circuit of the pitch system; if there is a problem with the backup power circuit, the main control system switches the control command and retracts the pitch through the AC power circuit of the pitch system; When an emergency occurs, the main control system issues an emergency shutdown control command to control the pitch control system to retract the pitches; within the specified time after the emergency shutdown control command is issued, if the wind turbine generator speed has not dropped to a safe speed range, the main control system performs an emergency yaw operation through the yaw system to make the wind turbine yaw away from the main wind direction; During the emergency yaw process, the generator speed continues to decrease. When the generator speed drops to a safe speed range, the main control system performs main shaft braking operation through the brake system to lock the flywheel and stop the emergency yaw operation at the same time, thus completing the entire process of emergency shutdown operation of the wind turbine set. The specific process logic of the main shaft braking operation performed by the braking system is as follows: when the main control system issues an emergency shutdown control command, the main control system continues to detect the generator speed of the wind turbine; when the emergency shutdown control command is issued, if the generator speed is higher than the safe speed range, the main control system will not activate the braking system except through manual braking and emergency button human intervention; if the main control system detects that the generator speed is reduced to within the safe speed range, the main control system will activate the braking system and perform the main shaft braking operation until the wind turbine completes the emergency shutdown process.

2. The emergency safety control method of a wind turbine generator set according to claim 1, characterized in that: The hardware-level circuit of the traditional wind turbine is improved so that the pitch system, yaw system and brake system therein become independent control modes and are not affected by the hardware connection relationship; the improvement method includes: after the safety chain is disconnected, the brake system will not be put into operation at the same time; the specific improvement operation is: in the traditional wind turbine, a specific node in the safety chain circuit is short-circuited, and the specific node is the node where the safety chain circuit is connected in series with the brake circuit.

3. The emergency safety control method of a wind turbine generator set according to claim 2, characterized in that: The improvement method also includes: after the safety chain is disconnected, the yaw system still operates normally; the specific improvement operation is: in the traditional wind turbine, a relay is added to the safety chain circuit, and the relay independently controls the circuit of the yaw system.

4. The emergency safety control method of a wind turbine generator set according to claim 1, characterized in that: The specific control process logic of the pitch retraction operation performed by the pitch control system is as follows: when an emergency occurs, the main control system first issues a normal pitch retraction command, and performs the pitch retraction operation through the AC power circuit of the pitch control system; if the blades of the wind turbine are not reached to the specified position within the first time, the main control system issues an emergency pitch retraction command, and performs the pitch retraction operation through the backup power circuit of the pitch control system.

5. The emergency safety control method of a wind turbine generator set according to claim 4, characterized in that: After the main control system issues an emergency propeller retraction command, the main control system detects the propeller retraction operation status through the variable pitch system; after the command is issued and continues for a second time, if it is detected that at least one propeller blade has not been retracted to the limit switch position, and the pitch angle of the propeller blade is less than 70 degrees, the main control system sets the emergency propeller retraction command and performs the propeller retraction operation again through the AC power supply circuit of the variable pitch system.

6. The emergency safety control method of a wind turbine generator set according to claim 1, characterized in that: The specific process logic of the emergency yaw operation performed by the yaw system is as follows: when the main control system issues an emergency shutdown control command, the timing starts at the same time. When the third time is reached, if the main control system detects that the generator speed of the wind turbine is still greater than the safe speed range, the yaw system performs an emergency yaw operation to make the wind turbine start to yaw.

7. The emergency safety control method of a wind turbine generator set according to claim 6, characterized in that: The yaw direction of the wind turbine is the direction away from the main wind direction. If the deviation angle between the nacelle direction of the current wind turbine and the main wind direction is less than 0 degrees, the yaw direction is counterclockwise; if the deviation angle between the nacelle direction and the main wind direction is greater than 0 degrees, the yaw direction is clockwise. While the emergency yaw operation is in progress, if the main control system detects that the generator speed of the wind turbine set drops to a safe speed range, the emergency yaw operation will be stopped.

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