Method of pitch control and control method and controller for a wind turbine generator system

Abstract

A variable pitch control method for a wind turbine generator system, a control method and a controller are disclosed. The variable pitch control method comprises: determining whether a communication with a main controller of the wind turbine generator system is interrupted in a variable pitch state; controlling a variable pitch system to operate in a redundant operation mode in response to the communication with the main controller being interrupted, wherein in the redundant operation mode, a given variable pitch speed is controlled to change from a first speed value at which the communication with the main controller is interrupted to 0; detecting whether the communication with the main controller is restored during the redundant operation mode; performing a variable pitch operation based on the given variable pitch speed received from the main controller in response to the communication with the main controller being restored during the redundant operation mode or the communication with the main controller being restored at the end of the redundant operation mode.

Description

Technical Field

[0001] This disclosure generally relates to the field of wind power generation technology, and more specifically, to a pitch control method and pitch controller for a wind turbine generator set, a control method and controller for a wind turbine generator set, and a wind turbine generator set including the pitch controller and / or the controller. Background Technology

[0002] Currently, the control method of the pitch control system of wind turbine generator sets is mainly implemented in the following way: the main control system of the wind turbine generator set detects the actual speed value of the generator and sets the target speed value according to the characteristics of the generator set model. By performing PID calculation on the deviation between the target speed value and the actual speed value, the pitch angle change is output and the communication data is transmitted to the pitch control system through the slip ring via the signal line. After receiving the pitch angle change command issued by the main control system, the pitch control system executes the pitch operation to realize the pitch adjustment function, thereby achieving the purpose of maximum power point tracking and stable speed of the wind turbine generator set.

[0003] A slip ring is a precision power transmission device that uses the sliding contact, electrostatic coupling, or electromagnetic coupling of a conductive ring to transmit electrical signals and energy between rotating parts on a fixed base and rolling or sliding parts. Slip rings are widely used in all electromechanical systems requiring unrestricted, continuous, or intermittent 360° rotation, multi-path rotational power, data, and signals. Slip rings simplify the structure of communication systems and prevent wires from twisting during rotation. The structural design of slip rings must ensure reliable contact and guarantee continuous connection of all lines.

[0004] However, because slip rings transmit dozens of different electrical signals, including high-frequency alternating current, high-voltage alternating current, high-current alternating current, and weak DC signals, these signals interfere with each other during transmission, severely affecting the accuracy of information transmission. Interference generated during signal transmission includes electrostatic induction coupling, magnetic field induction coupling, and electromagnetic field induction coupling. Electrostatic induction coupling interference is caused by the capacitance between conductors and the distributed capacitance between rings in the slip ring, generating electrostatic induced voltage. Because the conductors and rings of the slip ring are very close together, when alternating current passes through, mutual inductance causes mutual inductance voltages in adjacent conductors and rings, i.e., magnetic field induction coupling interference. When the voltage and frequency of the interference source are high, electromagnetic field induction coupling interference can also occur. Furthermore, the input signal of the slip ring may experience interference due to sudden changes in current and voltage during the switching process of the input lines.

[0005] Communication data is a digital signal, which is quite sensitive. Interference with the conductive slip ring can easily affect the stability and reliability of the communication data. The main control system controls the operation of the pitch system and also transmits various data through the conductive slip ring. Therefore, interference with the conductive slip ring often causes communication interruptions (communication is interrupted for a short time, such as 1 second, and then resumes), resulting in the shutdown of the wind turbine. Alternatively, interference with the communication data may cause the pitch system to receive incorrect pitch angle command data, thus causing the pitch system to malfunction.

[0006] Currently, for faults caused by conductive slip ring interference, the only solution is to shut down the wind turbine to ensure its safety. That is, when the main control system detects a communication error, it will immediately execute a pitch-down shutdown to ensure the wind turbine's safety. This leads to unnecessary shutdowns and affects the wind turbine's power generation. The main reasons for wind turbine shutdowns due to conductive slip ring interference are as follows.

[0007] First, the pitch system cannot collect wind speed data and cannot determine the current wind speed value. Since wind speed is transient, the pitch system must not operate blindly after a communication interruption, otherwise it could easily endanger the safety of the wind turbine generator. Second, the pitch system cannot detect the generator or low-speed shaft rotation speed. Even if the main control system of some wind turbine generators transmits the generator speed value to the pitch system, the data transmission still occurs through a slip ring. If the slip ring experiences a momentary failure, data transmission is ineffective. In this case, the pitch system must not operate blindly, otherwise it could easily endanger the safety of the wind turbine generator. Third, while communication data verification can effectively prevent malfunctions in the pitch system, it cannot provide fault tolerance for slip ring momentary failures. That is, after the pitch system detects an error in the verification result of the communication data, it will immediately execute pitch retraction and shutdown to ensure the safety of the wind turbine generator set; Fourth, although wireless communication can be used for communication redundancy to eliminate the impact of the conductive slip ring communication interruption, wireless communication is susceptible to shielding or interference and requires the addition of many wireless modules, so the modification cost is high and it is not suitable for large-scale production; Finally, although the wind turbine generator set can be allowed to operate in a fault-tolerant manner without triggering a fault when the conductive slip ring communication is interrupted, this method has a certain degree of blindness and poses a significant safety hazard to the wind turbine generator set. If the blades on the normal shaft are adjusting the pitch at this time, the "angle inconsistency fault" will be triggered very quickly, so the fault-tolerant operation time will be very short. Summary of the Invention

[0008] Therefore, this disclosure provides a pitch control method and pitch controller for a wind turbine generator set, a control method and controller for a wind turbine generator set, and a wind turbine generator set including the pitch controller and / or the controller, which can achieve short-term fault-tolerant operation of the pitch system when communication is interrupted between the controller of the wind turbine generator set and a single pitch controller, thereby reducing the failure rate and downtime of the wind turbine generator and reducing power generation loss.

[0009] In one general aspect, a pitch control method for a wind turbine generator set is provided, the pitch control method comprising: determining, in a pitch state, whether communication with a main controller of the wind turbine generator set is interrupted; in response to the interruption of communication with the main controller, controlling the pitch system to operate in a redundant operating mode, wherein, in the redundant operating mode, controlling a given pitch speed to change from a first speed value at the time of the interruption of communication with the main controller to 0; detecting whether communication with the main controller is restored during the redundant operating mode; and, in response to the restoration of communication with the main controller during the redundant operating mode, or the restoration of communication with the main controller at the end of the redundant operating mode, performing a pitch operation based on a given pitch speed received from the main controller.

[0010] Optionally, the pitch control method further includes: in response to the failure to restore communication with the main controller at the end of the redundant operation mode, controlling the pitch system to perform a feathering shutdown operation.

[0011] Optionally, the steps for controlling the pitch system to operate in redundant mode include: determining a first speed value for the given pitch speed when communication with the main controller is interrupted; and controlling the given pitch speed to change from the first speed value to 0 based on a preset rate of change corresponding to the first speed value.

[0012] Optionally, the steps of controlling the pitch system to operate in redundant operation mode include: determining a first speed value for the given pitch speed when communication with the main controller is interrupted, and obtaining the actual rotational speed of the pitch motor; in response to the difference between the first speed value and the actual rotational speed of the pitch motor being less than a predetermined threshold, controlling the given pitch speed to change from the first speed value to 0 based on the first speed value and the actual rotational speed of the pitch motor.

[0013] Optionally, the step of controlling the given pitch speed to change from the first speed value to 0 based on the first speed value and the actual rotational speed of the pitch motor includes: determining the acceleration of the pitch motor based on the preset target rotational speed of the pitch motor and the actual rotational speed of the pitch motor, wherein the target rotational speed is 0; determining a new given pitch speed based on the actual rotational speed and acceleration of the pitch motor; and controlling the pitch motor to perform pitch adjustment according to the new given pitch speed, so as to gradually reduce the given pitch speed from the first speed value to 0.

[0014] Optionally, the pitch control method further includes: in response to the difference between the first speed value and the actual speed of the pitch motor being greater than or equal to a predetermined threshold, controlling the pitch system to perform a feathering stop operation.

[0015] In another general aspect, a control method for a wind turbine generator set is provided, the control method comprising: determining whether communication between the main controller of the wind turbine generator set and each pitch system is interrupted; in response to determining that communication between the main controller and only one pitch system is interrupted, determining whether a given pitch speed is 0; and in response to determining that the given pitch speed is not 0, entering a redundant control mode, wherein, in the redundant control mode, the one pitch system executes the pitch control method.

[0016] Optionally, the control method further includes: in response to determining that communication between the main controller and at least two pitch systems has been interrupted, disconnecting the safety chain of the wind turbine generator to control the wind turbine generator to shut down.

[0017] Optionally, the control method further includes: waiting for a predetermined time in response to determining that a given pitch speed is 0; determining whether communication between the main controller and the pitch system has been restored within the predetermined time; and disconnecting the safety chain of the wind turbine generator set in response to the predetermined time expiring and communication between the main controller and the pitch system still not being restored, so as to control the wind turbine generator set to shut down.

[0018] Optionally, the control method further includes: determining whether a given pitch speed becomes a non-zero value within the predetermined time; and disconnecting the safety chain of the wind turbine generator in response to the given pitch speed becoming a non-zero value within the predetermined time and the communication between the main controller and the pitch system not being restored, so as to control the wind turbine generator to shut down.

[0019] Optionally, the control method further includes: in response to the resumption of communication between the main controller and the pitch system within the predetermined time or when the predetermined time expires, controlling the wind turbine generator to exit redundant operation and enter normal operation mode.

[0020] In another general aspect, a computer-readable storage medium storing a computer program is provided, characterized in that, when the computer program is executed by a processor, it implements the pitch control method as described above or the control method as described above.

[0021] In another general aspect, a pitch controller is provided, the pitch controller comprising: a processor; and a memory storing a computer program that, when executed by the processor, implements the pitch control method as described above.

[0022] In another general aspect, a controller is provided, the controller comprising: a processor; and a memory storing a computer program that, when executed by the processor, implements the control method as described above.

[0023] In another general aspect, a wind turbine generator set is provided, the wind turbine generator set including the pitch controller as described above and / or the controller as described above.

[0024] According to embodiments of this disclosure, through the collaborative control of the main control system and the pitch system of the wind turbine generator set, fault-tolerant operation after communication interruption can be achieved, and the safety of the wind turbine generator set during fault-tolerant operation can be guaranteed. Therefore, it can handle the interruption situation of frequent and alternating communication failures triggered by the three axes due to abnormal conductive slip rings.

[0025] Furthermore, according to embodiments of this disclosure, fault-tolerant operation after communication interruption is achieved by utilizing the characteristics of PID control, resulting in high reliability and stability, and eliminating the need for wind speed prediction. Since the newly calculated given pitch speed during fault-tolerant operation is not significantly different from the given pitch speed of the main control system, pitch control can continue for a period of time, thus ensuring the consistency of the angles of each blade and achieving fault-tolerant operation for a longer period.

[0026] Furthermore, according to embodiments of this disclosure, fault-tolerant operation after communication interruption is achieved by using PID control logic in the form of a "speed-acceleration controller," eliminating the need for complex data acquisition and statistics, and enabling autonomous adjustment of the given pitch speed. Simultaneously, the parameters of the "speed-acceleration controller" can directly utilize the corresponding parameters of the wind turbine's main control system, thereby achieving better consistency in the three-blade angle adjustment. This minimizes the deviation between the new given pitch speed calculated by the pitch system and the given pitch speed sent by the main control system, ensuring the safe operation of the wind turbine.

[0027] Further aspects and / or advantages of the general concept of this disclosure will be set forth in part in the description which follows, and in part will be clear from the description or may be learned by practice of the general concept of this disclosure. Attached Figure Description

[0028] The above and other objects and features of the embodiments of this disclosure will become clearer from the following description taken in conjunction with the accompanying drawings illustrating the embodiments, wherein:

[0029] Figure 1 This is a diagram illustrating an example of a communication interruption between the main controller and the pitch controller during pitch operation of a wind turbine generator set;

[0030] Figure 2 This is a flowchart illustrating a pitch control method according to an embodiment of the present disclosure;

[0031] Figure 3 This is a flowchart illustrating a control method for a wind turbine generator set according to an embodiment of the present disclosure;

[0032] Figure 4 This is a block diagram illustrating a controller for a wind turbine generator set according to an embodiment of the present disclosure. Detailed Implementation

[0033] The following detailed embodiments are provided to aid the reader in gaining a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will become apparent upon understanding this disclosure. For example, the order of operations described herein is merely illustrative and is not limited to those orders set forth herein, but may be changed as will become clear upon understanding this disclosure, except for operations that must occur in a specific order. Furthermore, for clarity and conciseness, descriptions of features known in the art may be omitted.

[0034] The features described herein may be implemented in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein are provided only to illustrate some of the many feasible ways of implementing the methods, apparatus, and / or systems described herein, which will become clear upon understanding the disclosure of this application.

[0035] As used herein, the term “and / or” includes any one of the associated listed items and any combination of any two or more.

[0036] Although terms such as “first,” “second,” and “third” may be used herein to describe various components, assemblies, regions, layers, or parts, these components, assemblies, regions, layers, or parts should not be limited by these terms. Rather, these terms are used only to distinguish one component, assembly, region, layer, or part from another. Thus, without departing from the teaching of the examples described herein, the first component, first assembly, first region, first layer, or first part referred to as the first component, first assembly, first region, first layer, or first part may also be referred to as the second component, second assembly, second region, second layer, or second part.

[0037] In the specification, when an element (such as a layer, region, or substrate) is described as being "on" another element, "connected to," or "bonded to" another element, the element may be directly "on" another element, directly "connected to," or "bonded to" the other element, or one or more other elements may be present in between. Conversely, when an element is described as being "directly on" another element, "directly connected to," or "directly bonded to" another element, no other elements may be present in between.

[0038] The terminology used herein is for the purpose of describing various examples only and is not intended to limit disclosure. Unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well. The terms “comprising,” “including,” and “having” indicate the presence of the described features, quantities, operations, components, elements, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0039] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains upon understanding this disclosure. Unless expressly defined herein, terms (such as those defined in a general dictionary) shall be interpreted as having a meaning consistent with their meaning in the context of the relevant field and in this disclosure, and shall not be interpreted in an idealized or overly formalistic manner.

[0040] Furthermore, in the description of the examples, detailed descriptions of well-known related structures or functions will be omitted when it is believed that such detailed descriptions would lead to a vague interpretation of this disclosure.

[0041] Figure 1 This diagram illustrates an example of a communication interruption between the main controller and the pitch controller during pitch control operation of a wind turbine. Gusts occur during the pitch control operation of the wind turbine.

[0042] Reference Figure 1 Curve 101 represents the given pitch speed issued by the main controller of the wind turbine generator, and curve 102 represents the actual rotational speed of the pitch motor. The horizontal axis represents time, and the vertical axis only shows the trend of the two curves, not their numerical relationship. Before time t1, the pitch system receives the speed command (i.e., the given pitch speed) issued by the main controller and performs pitch operation. From time t1 onwards, communication (e.g., DP communication) between the main controller and the pitch system is interrupted. Due to the loss of communication data, the speed command received by the pitch system is 0, and the enable signal sent by the main controller also becomes low, so the pitch system stops pitching. At time t2, the speed command issued by the main controller returns to normal, and the pitch system receives the speed command again, thus resuming normal pitch operation. Here, the value of the speed command issued by the main controller is calculated based on the actual rotational speed of the wind turbine generator (or the actual position of the blades) and the rated rotational speed (or the target position of the blades). This disclosure does not impose any limitations on this, and therefore its detailed description is omitted.

[0043] However, to protect the safety of the wind turbine generator set, if the time interval between time t1 and time t2 is greater than 220ms, the wind turbine generator set needs to undergo a fault shutdown. This is because: firstly, the pitch control system cannot monitor the rotor speed and cannot operate blindly; secondly, in... Figure 1 In the scenario shown, if a single pitch control system stops adjusting the pitch, while the other two pitch control systems are functioning normally under normal communication conditions, a three-blade angle inconsistency fault will be triggered, causing the wind turbine to shut down.

[0044] To address the aforementioned issues, the pitch control method and pitch controller for wind turbine generators, as well as the control method and controller for wind turbine generators according to embodiments of this disclosure, allow for fault-tolerant operation during communication interruptions. Specifically, a self-learning function for the given pitch speed change rate can be set within the pitch system, or a "speed-acceleration controller" logic can be set within the pitch controller. Thus, when a communication interruption occurs between a single pitch system and the main controller, if the pitch system is performing pitch operation, the pitch controller can record the given pitch speed before the communication interruption, decrease the given pitch speed according to a certain rate of change, thereby obtaining a new given pitch speed, and control the pitch motor operation. During the process of the new given pitch speed increasing or decreasing to 0, it is determined whether communication has been restored. If communication is restored, the pitch system can re-obtain the given pitch speed from the main controller, thereby performing normal pitch operation. However, if communication has not been restored when the new given pitch speed increases or decreases to 0, a fault shutdown is triggered to protect the safety of the wind turbine generator.

[0045] Figure 2 This is a flowchart illustrating a pitch control method according to an embodiment of the present disclosure. The pitch control method can be executed by individual pitch controllers of a wind turbine generator set.

[0046] Reference Figure 2 In step S201, it can be determined whether communication with the main controller of the wind turbine generator is interrupted in the pitch state.

[0047] Specifically, when the port status word read from the main controller is a specific value (e.g., but not limited to 0), it can be determined that communication with the main controller has been interrupted. On the other hand, when the heartbeat bit signal received from the main controller becomes 0, it can be determined that communication with the main controller has been interrupted.

[0048] In step S202, in response to an interruption in communication with the main controller of the wind turbine generator, the pitch system can be controlled to operate in a redundant operating mode. In redundant operating mode, the given pitch speed can be controlled to change from a first speed value at the time of the communication interruption with the main controller to 0. The redundant operating mode will be described in detail later with reference to examples.

[0049] In step S203, it is possible to detect whether communication with the main controller has been restored during redundant operation mode.

[0050] In step S204, in response to the resumption of communication with the master controller during redundant operation mode or at the end of redundant operation mode, pitch operation may be performed based on a given pitch speed received from the master controller.

[0051] Alternatively, if communication with the main controller is not restored when the redundant operation mode ends, the pitch system can be controlled to perform a feathering shutdown operation to protect the safety of the wind turbine generator.

[0052] The following describes in detail how to control the pitch system to operate in redundant mode.

[0053] In one scenario, a first speed value for the given pitch speed can be determined first when communication with the main controller is interrupted, and then the given pitch speed can be controlled to change from the first speed value to 0 based on a preset rate of change corresponding to the first speed value.

[0054] According to embodiments of this disclosure, a preset rate of change corresponding to a first speed value can be determined as follows: First, the speed range to which the first speed value belongs can be determined. For example, a speed range can be defined as 0.5 degrees / second. However, this disclosure is not limited thereto. The range of the speed range can be greater than or less than 0.5 degrees / second. After determining the speed range to which the first speed value belongs, the rate of change can be determined based on the various speed values ​​within the speed range to which the first speed value belongs, before the given pitch speed reaches the first speed value. Specifically, the sum of the differences between the various speed values ​​within the speed range to which the first speed value belongs, before the given pitch speed reaches the first speed value, can be calculated, and the ratio of this sum to the number of various speed values ​​within the speed range to which the given pitch speed belongs, before the given pitch speed reaches the first speed value, can be used as the rate of change.

[0055] Table 1 shows an example of calculating the rate of change of a given pitch speed. As shown in Table 1, a speed interval of 0.5 degrees / second is used. Within the speed interval of 0 to 0.5 degrees / second, communication is interrupted when the given pitch speed is 0.45 degrees / second. At this time, the sum of the differences in the given pitch speeds within the speed interval of 0 to 0.5 degrees / second is 0.123, while the number of given pitch speeds is 16, and the ratio of the two is 0.0077. Therefore, the preset rate of change corresponding to the first speed value can be determined to be 0.0077. Thus, when communication is interrupted, the given pitch speed can change to 0 at a rate of 0.0077 degrees / second per sampling period (e.g., but not limited to 20 milliseconds). During this process, the pitch motor can be controlled to operate with the newly calculated given pitch speed. In this case, the time for the given pitch speed to change from 0.45 degrees / second to 0 is approximately 0.45 / 0.0077 = 58 sampling periods. When the sampling period is 20 milliseconds, the duration of the redundant operation mode can reach 58 × 20 milliseconds = 1.16 seconds, which is much longer than the fault trigger time of communication interruption in the prior art (220 milliseconds). Therefore, the pitch control method according to the embodiments of this disclosure can effectively cope with short-term communication interruptions and keep the pitch system in a pitch-adjusting state when communication interruption occurs, thereby protecting the safety of the wind turbine generator and reducing power generation loss.

[0056] Table 1

[0057]

[0058] In another scenario, a first speed value for the given pitch speed can be determined when communication with the main controller is interrupted, and the actual rotational speed of the pitch motor can be obtained. When the difference between the first speed value and the actual rotational speed of the pitch motor is less than a predetermined threshold, the given pitch speed can be controlled to change from the first speed value to 0 based on the first speed value and the actual rotational speed of the pitch motor. However, when the difference between the first speed value and the actual rotational speed of the pitch motor is greater than or equal to the predetermined threshold, the redundant operation mode can be exited, and the pitch system can be controlled to perform a feathering stop operation.

[0059] Specifically, the pitch controller can be configured with speed-acceleration controller logic to control the given pitch speed from a first speed value to 0. First, the acceleration of the pitch motor can be determined based on a preset target speed and the actual speed of the pitch motor; here, the target speed can be 0. Then, a new set pitch speed can be determined based on the actual speed and acceleration of the pitch motor. Finally, the pitch motor can be controlled to perform pitch adjustment according to the new set pitch speed, gradually reducing the given pitch speed from the first speed value to 0. This speed-acceleration controller logic can be implemented similarly to PID control logic. For example, the target value of the PID control logic can be set to 0, the actual speed of the pitch motor can be used as the feedback value of the PID control logic, and the sum of the output value of the PID control logic and the actual speed of the pitch motor can be used to determine the given pitch speed. Optionally, the output value of the PID control logic and the sum of the output value of the PID control logic and the actual speed of the pitch motor can be limited values. This avoids situations where the set pitch speed is too high due to excessively high output values ​​of the PID control logic or excessively high actual speeds of the pitch motor. According to embodiments of this disclosure, the above-described PID control logic can be specifically implemented as PD control logic, that is, the integral coefficient in the PID is set to 0. Optionally, the proportional coefficient and derivative coefficient of the PD control logic can be the same as the proportional coefficient and derivative coefficient of the main control PID control logic. The proportional coefficient and derivative coefficient can be determined by those skilled in the art using various existing methods, which will not be elaborated here.

[0060] By applying a speed-accelerometer, autonomous adjustment of a given pitch speed can be achieved without complex data acquisition and statistics. Furthermore, the parameters of the speed-accelerometer can directly utilize the corresponding parameters from the wind turbine's main control system, thereby achieving better consistency in the three-blade angle adjustment. This means minimizing the deviation between the new given pitch speed calculated by the pitch controller and the given pitch speed sent by the main control system, ensuring the safe operation of the wind turbine.

[0061] Figure 3 This is a flowchart illustrating a control method for a wind turbine generator set according to an embodiment of the present disclosure. The control method can be executed by the main controller of the wind turbine generator set.

[0062] Reference Figure 3 In step S301, it can be determined whether communication between the main controller of the wind turbine generator set and each pitch system has been interrupted. Specifically, when the port status word of the main controller is a specific value (e.g., but not limited to 0), it can be determined that communication with the pitch controller has been interrupted. On the other hand, when the heartbeat bit signal received from the pitch controller becomes 0, it can be determined that communication with the pitch controller has been interrupted.

[0063] In step S302, in response to determining that communication between the main controller and only one pitch system is interrupted, it can be determined whether the given pitch speed is 0.

[0064] In step S303, in response to determining that the given pitch speed is not zero, the system enters a redundant control mode. In redundant control mode, a pitch system whose communication with the master controller is interrupted can execute the pitch control method described above.

[0065] Optionally, in response to a determination that communication between the main controller and at least two pitch systems has been interrupted, the safety chain of the wind turbine generator can be broken to control the wind turbine generator shutdown. In other words, to protect the operational safety of the wind turbine generator, each pitch control system cannot operate in redundant operation mode when communication between the main controller and at least two pitch systems is interrupted.

[0066] On the other hand, if the given pitch speed is determined to be 0, a predetermined time (e.g., but not limited to 500 milliseconds) can be waited for. That is, when the wind turbine is not in pitch control mode, if communication between the main controller and only one pitch system is interrupted, the main controller can run for the predetermined time without immediately shutting down the turbine. Simultaneously, it can be determined within the predetermined time whether communication between the main controller and the one pitch system has been restored. If communication between the main controller and the one pitch system has not been restored by the end of the predetermined time, the safety chain of the wind turbine can be disconnected to control the wind turbine shutdown. If communication between the main controller and the one pitch system is restored within the predetermined time or upon its expiration, the wind turbine can be controlled to exit redundant operation and enter normal operation mode. Optionally, it can also be determined within the predetermined time whether the given pitch speed becomes a non-zero value. If the given pitch speed becomes a non-zero value within the predetermined time and communication between the main controller and the one pitch system has not been restored, the safety chain of the wind turbine can be disconnected to control the wind turbine shutdown. In other words, when communication between a single pitch control unit and the main controller of the wind turbine is interrupted, if the pitch system is adjusting the pitch, the pitch controller records the given speed before the communication interruption, and decreases the given speed according to the preset rate of change to obtain a new given speed, and controls the pitch motor to run; when the new given speed increases or decreases to 0, it determines whether the communication with the main controller has been restored. If the communication is restored, it switches to main control again; if the communication is still not restored, it triggers a fault shutdown to protect the wind turbine safety.

[0067] Figure 4 This is a block diagram illustrating a controller for a wind turbine generator set according to an embodiment of the present disclosure. The controller may be a main controller or a pitch controller for the wind turbine generator set.

[0068] Reference Figure 4The controller 400 of the wind turbine generator set according to embodiments of the present disclosure may include a processor 410 and a memory 420. The processor 410 may include (but is not limited to) a central processing unit (CPU), a digital signal processor (DSP), a microcomputer, a field-programmable gate array (FPGA), a system-on-a-chip (SoC), a microprocessor, an application-specific integrated circuit (ASIC), etc. The memory 420 stores computer programs to be executed by the processor 410. The memory 420 includes high-speed random access memory and / or non-volatile computer-readable storage media. When the processor 410 executes the computer program stored in the memory 420, the pitch control method or the control method of the wind turbine generator set described above can be implemented.

[0069] Alternatively, the controller 400 can communicate with other components in the wind turbine generator set via wired / wireless communication, and can also communicate with other devices in the wind farm via wired / wireless communication. Furthermore, the controller 400 can communicate with devices outside the wind farm via wired / wireless communication.

[0070] The pitch control method and control method for a wind turbine generator set according to embodiments of this disclosure can be programmed into a computer program and stored on a computer-readable storage medium. When the computer program is executed by a processor, the pitch control method or control method for a wind turbine generator set as described above can be implemented. Examples of computer-readable storage media include: read-only memory (ROM), random access programmable read-only memory (PROM), electrically erasable programmable read-only memory (EEPROM), random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), flash memory, non-volatile memory, CD-ROM, CD-R, CD+R, CD-RW, CD+RW, DVD-ROM, DVD-R, DVD+R, DVD-RW, DVD+RW, DVD-RAM, BD-ROM, BD-R, BD-R LTH, BD-RE, Blu-ray or optical disc storage, hard disk drive (HDD), solid-state drive (SSD), card storage (such as multimedia cards, secure digital (SD) cards, or ultra-fast digital (XD) cards), magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid-state drive, and any other device configured to store computer programs and any associated data, data files, and data structures in a non-transitory manner and to provide the computer programs and any associated data, data files, and data structures to a processor or computer so that the processor or computer can execute the computer programs. In one example, the computer programs and any associated data, data files, and data structures are distributed across a networked computer system, such that the computer programs and any associated data, data files, and data structures are stored, accessed, and executed in a distributed manner through one or more processors or computers.

[0071] On the other hand, the pitch control method and the control method of the wind turbine generator set according to the embodiments of the present disclosure can be implemented as a computer program product including a computer program. When the computer program is executed by a processor, the pitch control method or the control method of the wind turbine generator set described above is implemented.

[0072] According to embodiments of this disclosure, through the collaborative control of the main control system and the pitch system of the wind turbine generator set, fault-tolerant operation after communication interruption can be achieved, and the safety of the wind turbine generator set during fault-tolerant operation can be guaranteed. Therefore, it can handle the interruption situation of frequent and alternating communication failures triggered by the three axes due to abnormal conductive slip rings.

[0073] Furthermore, according to embodiments of this disclosure, fault-tolerant operation after communication interruption is achieved by utilizing the characteristics of PID control, resulting in high reliability and stability, and eliminating the need for wind speed prediction. Since the newly calculated given pitch speed during fault-tolerant operation is not significantly different from the given pitch speed of the main control system, pitch control can continue for a period of time, thus ensuring the consistency of the angles of each blade and achieving fault-tolerant operation for a longer period.

[0074] Furthermore, according to embodiments of this disclosure, fault-tolerant operation after communication interruption is achieved by using a "speed-acceleration controller" logic, which eliminates the need for complex data acquisition and statistics, enabling autonomous adjustment of a given pitch speed. Simultaneously, the parameters of the "speed-acceleration controller" can directly utilize the corresponding parameters of the wind turbine's main control system, thereby achieving better three-blade angle consistency adjustment. This minimizes the deviation between the new given pitch speed calculated by the pitch system and the given pitch speed sent by the main control system, ensuring the safe operation of the wind turbine.

[0075] While some embodiments of this disclosure have been shown and described, those skilled in the art will understand that modifications may be made to these embodiments without departing from the principles and spirit of this disclosure, which are defined by the claims and their equivalents.

Claims

1. A pitch control method for a wind turbine generator set, characterized in that, The pitch control method includes: Determine whether communication with the main controller of the wind turbine generator has been interrupted during pitch control. In response to an interruption in communication with the main controller, the pitch control system operates in a redundant operating mode. In the redundant operating mode, the given pitch speed is controlled to change from the first speed value at the time of the interruption in the communication with the main controller to 0 as follows: the given speed before the communication interruption is recorded, and the given speed is decreased according to a preset rate of change to obtain a new given speed. The pitch motor is then controlled to operate according to the new given speed. During redundant operation mode, detect whether communication with the main controller has been restored; In response to the resumption of communication with the master controller during redundant operation mode, or at the end of redundant operation mode, pitch operation is performed based on a given pitch speed received from the master controller.

2. The pitch control method as described in claim 1, characterized in that, The pitch control method further includes: In response to the failure to restore communication with the main controller when the redundant operation mode ends, the control pitch system performs a feathering shutdown operation.

3. The pitch control method as described in claim 1, characterized in that, The steps for controlling the pitch system to operate in redundant mode include: Determine the first speed value for the given pitch speed when communication with the main controller is interrupted; The given pitch speed is controlled to change from the first speed value to 0 based on a preset rate of change corresponding to the first speed value.

4. The pitch control method as described in claim 1, characterized in that, The steps for controlling the pitch system to operate in redundant mode include: Determine the first speed value given the pitch speed when communication with the main controller is interrupted, and obtain the actual speed of the pitch motor; In response to the difference between the first speed value and the actual speed of the pitch motor being less than a predetermined threshold, the given pitch speed is controlled to change from the first speed value to 0 based on the first speed value and the actual speed of the pitch motor.

5. The pitch control method as described in claim 4, characterized in that, Based on the first speed value and the actual rotational speed of the pitch motor, the steps for controlling the given pitch speed to change from the first speed value to 0 include: The acceleration of the pitch motor is determined based on the preset target speed and the actual speed of the pitch motor, where the target speed is 0. Determine the new pitch setpoint based on the actual rotational speed and acceleration of the pitch motor; The pitch motor is controlled to perform pitch adjustment according to the new pitch setpoint speed, so as to gradually decrease the given pitch speed from the first speed value to 0.

6. The pitch control method as described in claim 5, characterized in that, The pitch control method further includes: In response to the difference between the first speed value and the actual speed of the pitch motor being greater than or equal to a predetermined threshold, the pitch system is controlled to perform a feathering stop operation.

7. A control method for a wind turbine generator set, characterized in that, The control method includes: Determine whether the communication between the main controller of the wind turbine generator and each pitch system has been interrupted; In response to the determination that communication between the main controller and only one pitch system has been interrupted, determine whether the given pitch speed is 0; In response to the determination that the given pitch speed is not zero, the system enters redundant control mode. In the redundant control mode, the pitch system executes the pitch control method as described in any one of claims 1 to 6.

8. The control method as described in claim 7, characterized in that, The control method further includes: In response to determining that communication between the main controller and at least two pitch systems has been interrupted, the safety chain of the wind turbine is disconnected to control the wind turbine shutdown.

9. The control method as described in claim 8, characterized in that, The control method further includes: In response to determining that a given pitch speed is 0, wait for a predetermined time; Within the predetermined time, determine whether communication between the main controller and the pitch system has been restored; In response to the expiration of the predetermined time and the failure to restore communication between the main controller and the pitch system, the safety chain of the wind turbine is disconnected to control the wind turbine to shut down.

10. The control method as described in claim 9, characterized in that, The control method further includes: Within the predetermined time period, determine whether the given pitch speed becomes a non-zero value; In response to a given pitch speed becoming non-zero within the predetermined time and communication between the main controller and the pitch system not being restored, the safety chain of the wind turbine is disconnected to control the wind turbine to shut down.

11. The control method as described in claim 10, characterized in that, The control method further includes: In response to the resumption of communication between the main controller and the pitch system within the predetermined time or when the predetermined time expires, the wind turbine generator is controlled to exit redundant operation and enter normal operation mode.

12. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the pitch control method as described in any one of claims 1 to 6 or the control method as described in any one of claims 7 to 11.

13. A pitch controller, characterized in that, The pitch controller includes: processor; and A memory storing a computer program that, when executed by a processor, implements the pitch control method as described in any one of claims 1 to 6.

14. A controller, characterized in that, The controller includes: processor; and A memory storing a computer program that, when executed by a processor, implements the control method as described in any one of claims 7 to 11.

15. A wind turbine generator set, characterized in that, The wind turbine generator set includes the pitch controller as described in claim 13 and / or the controller as described in claim 14.

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