CN114251236A

CN114251236A - Fault early warning method and fault early warning device of variable pitch driver

Info

Publication number: CN114251236A
Application number: CN202011010739.2A
Authority: CN
Inventors: 马磊; 王大为; 卢勇
Original assignee: Xinjiang Goldwind Science and Technology Co Ltd
Current assignee: Xinjiang Goldwind Science and Technology Co Ltd
Priority date: 2020-09-23
Filing date: 2020-09-23
Publication date: 2022-03-29
Anticipated expiration: 2040-09-23
Also published as: CN114251236B

Abstract

A fault early warning method and a fault early warning device of a variable pitch driver are disclosed. The fault early warning method comprises the following steps: calculating theoretical variable pitch voltage of the variable pitch motor based on the operation data of the variable pitch motor; acquiring actual variable pitch voltage of a variable pitch motor; and determining whether the pitch drive will fail based on the theoretical pitch voltage and the actual pitch voltage.

Description

Fault early warning method and fault early warning device of variable pitch driver

Technical Field

The present disclosure relates generally to the field of wind power generation technologies, and more particularly, to a fault early warning method and a fault early warning device for a pitch driver of a pitch system of a wind turbine generator system.

Background

With the gradual expansion of the scale of the wind generating set and the gradual improvement of the safety protection of the set, the power generation performance of the operation of the wind generating set, namely the improvement of the generated energy and the availability of the wind generating set, receives more and more attention. On the other hand, the safety of the wind generating set is strictly ensured while the power generation benefit is pursued.

In a wind power plant, one of the main functions of the pitch system is to act as a pneumatic brake system for the plant. The electric variable pitch system ensures the safe and stable operation of the wind generating set through various detection and control means and multiple redundancy design. Any shutdown caused by a fault will feather the blades to the 90 degree position. Therefore, the variable pitch system plays a crucial role in the stability and safety of the unit, and particularly as an aerodynamic brake, the variable pitch system is required to have high reliability and safety.

However, during operation of the wind turbine, a fault may occur in a pitch drive, a pitch motor, or a backup power supply of the pitch system, and the fault may result in the blade of the wind turbine not being retracted to a safe position (e.g., 88 degrees pitch angle). If the blades of the wind generating set cannot be retracted to the safe position, the rotating speed of the wind generating set cannot be reduced under the action of wind force, and the wind generating set is caused to overspeed and even run away. Especially, with the increasing number of the fans, the batch faults especially relate to the faults of unit safety, and are directly related to the development and fate of wind power enterprises, so that more and more attention is paid to the faults, and the faults are researched and applied to the detection of clamping paddles, the detection of the reliability of large parts, the detection of grid-connected safety and the like.

When the working condition of the propeller clamping is detected, the fault of the variable pitch drive is found to be the most frequent propeller clamping. By performing linear regression calculation on the total ratio of two faults, namely a fault of OK signal loss of a pitch drive and a fault of large blade position deviation, the linear correlation coefficient of the two faults is found to be 0.98295, so that the linear correlation coefficient of the two faults is very high (when r is 1, two variables are completely linearly correlated), namely the correlation degree of the fault common cause is very high. After the variable pitch driver breaks down, the variable pitch motor cannot be driven to operate, so that the blades cannot be withdrawn, and the safety of the wind generating set is seriously influenced.

In fact, in wind power enterprises, the operation of a wind generating set is very important, and the influence of the fault of the wind generating set on the whole system is huge. However, because there are many reasons (typically tens or even tens of reasons) for causing the failure of the pitch drive, and even the result of the superposition of many factors, if only the influence of external factors, such as temperature, wind intensity, capacitance voltage, load, etc., is analyzed, on one hand, feature extraction is difficult, and on the other hand, it is difficult to adapt to the failure of the pitch drive with different failure codes.

At present, for the fault of the variable pitch drive, a common method is to switch to the voltage of a power grid to directly supply power to the variable pitch motor after the fault of the variable pitch drive occurs, however, the method has certain limitation.

Firstly, because the power grid is alternating current, the method is only suitable for alternating current motors and is not suitable for direct current motors; the volume of the alternating current motor is much larger than that of the direct current motor, and along with the continuous increase of the unit capacity, the advantages of the direct current motor are more and more obvious and are more and more applied.

Secondly, when the wind turbine generator system runs, a power supply line of a power grid needs to be controlled and switched by a contactor, so that the contactor fails, and the wind turbine generator system is shut down due to fault and false triggering.

Thirdly, under the working condition, the shutdown feathering is to cut off the power to stop the motor, and the motor stops suddenly to cause larger vibration of the unit along with the increase of the capacity of the unit.

Disclosure of Invention

The embodiment of the disclosure provides a fault early warning method and a fault early warning device for a variable pitch driver, which can take errors in advance by early warning of faults of the variable pitch driver and prevent blades from being jammed.

In one general aspect, there is provided a fault pre-warning method of a pitch drive, the fault pre-warning method comprising: calculating theoretical variable pitch voltage of the variable pitch motor based on the operation data of the variable pitch motor; acquiring actual variable pitch voltage of a variable pitch motor; and determining whether the pitch drive will fail based on the theoretical pitch voltage and the actual pitch voltage.

Optionally, the operational data comprises an actual pitch speed of the pitch motor and/or an operational frequency of the pitch motor.

Optionally, the step of calculating the theoretical pitch voltage of the pitch motor comprises: and calculating the product of the actual variable pitch speed of the variable pitch motor and the operating frequency of the variable pitch motor to be used as the theoretical variable pitch voltage of the variable pitch motor.

Optionally, the step of calculating the theoretical pitch voltage of the pitch motor comprises: and acquiring theoretical variable pitch voltage corresponding to the actual variable pitch speed according to the actual variable pitch speed of the variable pitch motor and a linear relation obtained by fitting the historical variable pitch voltage of the variable pitch motor and the historical variable pitch speed.

Optionally, the step of determining whether the pitch drive will fail based on the theoretical pitch voltage and the actual pitch voltage comprises: and determining whether the variable pitch driver fails or not based on the size relationship between the theoretical variable pitch voltage and the actual variable pitch voltage and the size relationship between the actual variable pitch speed of the variable pitch motor and the given variable pitch speed.

Optionally, the step of determining whether the pitch drive will fail comprises: determining whether the actual variable pitch voltage is greater than N times of the theoretical variable pitch voltage for a threshold time, wherein N is a real number greater than 1; when the actual variable pitch voltage is longer than N times of the theoretical variable pitch voltage lasting threshold time, determining whether the actual variable pitch speed of the variable pitch motor reaches a given variable pitch speed; if the actual pitch speed reaches the given pitch speed, it is determined that the pitch drive will fail.

Optionally, the step of determining whether the pitch drive will fail based on the theoretical pitch voltage and the actual pitch voltage comprises: and determining whether the variable pitch driver is about to fail or not based on the size relation between the theoretical variable pitch voltage and the actual variable pitch voltage.

Optionally, the step of determining whether the pitch drive will fail comprises: determining whether the actual variable pitch voltage is greater than N times of the theoretical variable pitch voltage for a threshold time, wherein N is a real number greater than 1; and when the actual variable pitch voltage is greater than N times of the theoretical variable pitch voltage for the duration threshold time, determining that the variable pitch driver has a fault.

Optionally, the fault pre-warning method further includes: before calculating the theoretical variable pitch voltage of the variable pitch motor, whether the magnetic flux of the variable pitch motor is saturated or not is determined based on the magnetic flux information of the variable pitch motor contained in the output information of the variable pitch driver, and the variable pitch driver is determined to be in failure in response to the magnetic flux of the variable pitch motor being saturated.

Optionally, the fault pre-warning method further includes: before calculating the theoretical variable pitch voltage of the variable pitch motor, acquiring the torque lifting amount of the variable pitch driver, and determining that the variable pitch driver fails in response to the fact that the torque lifting amount of the variable pitch driver exceeds a preset threshold value.

In another general aspect, there is provided a fault handling method of a pitch drive, the fault handling method comprising: adjusting the output of the pitch drive in response to determining that the pitch drive will fail by a fault early warning method as described above; and after a predetermined time, controlling the output of the pitch drive to return to normal.

Optionally, the fault handling method further includes: in response to determining that a pitch drive will fail by a fault early warning method as described above, determining whether the risk is avoidable; in response to determining that the risk is avoidable, performing the step of adjusting the output of the pitch drive.

Optionally, the step of determining whether the risk is avoidable comprises: detecting the rotating speed of the wind generating set and the wind speed of the position where the wind generating set is located; determining whether the detected rotational speed is less than a threshold rotational speed and determining whether the detected wind speed is less than a threshold wind speed; in response to determining that the detected rotational speed is less than the threshold rotational speed and the detected wind speed is less than the threshold wind speed, determining that the risk is avoidable.

Optionally, the fault handling method further includes: responding to the fact that the variable pitch drive is determined to be in fault through the fault early warning method, and controlling the wind driven generator to yaw by a preset angle; detecting whether the rotating speed of the wind generating set is reduced or not; in response to detecting a drop in the rotational speed of the wind turbine generator system, the step of adjusting the output of the pitch drive is performed.

Optionally, adjusting the output of the pitch drive: including pausing the output of the pitch drive.

Optionally, adjusting the output of the pitch drive comprises: the output of the pitch drive is adjusted by reducing a given pitch speed provided to the pitch drive.

Optionally, the fault handling method further includes: determining whether the angle of each blade is consistent during the predetermined time in response to adjusting the output of the pitch drive; and controlling the wind generating set to stop in response to determining that the angles of the blades are inconsistent.

Optionally, the step of determining whether the angles of the respective blades are consistent during the predetermined time includes: setting the angle of a first blade at the moment when the variable pitch drive is determined to be in fault as a reference angle value, wherein the first blade is the blade corresponding to the determined variable pitch drive which is to be in fault; taking the sum of the reference angle value and the additional angle value as an upper angle limit value, and taking the difference between the reference angle value and the additional angle value as a lower angle limit value; monitoring whether the angles of other blades exceed an angle threshold range defined by an angle upper limit value and an angle lower limit value during the predetermined time; in response to monitoring that the angle of any of the blades is outside of the angle threshold range, determining that the angles of the blades are not consistent.

In another general aspect, there is provided a fault warning device of a pitch drive, the fault warning device comprising: the voltage calculation unit is configured to calculate a theoretical variable pitch voltage of the variable pitch motor based on the operation data of the variable pitch motor; the voltage acquisition unit is configured to acquire an actual variable pitch voltage of the variable pitch motor; and a fault early warning unit configured to determine whether the pitch drive will fail based on the theoretical pitch voltage and the actual pitch voltage.

In another general aspect, there is provided a fault handling apparatus of a pitch drive, the fault handling apparatus comprising: an output adjusting unit configured to adjust an output of the pitch drive in response to the fault pre-warning device determining that the pitch drive will fail; and an output restoration unit configured to control the output of the pitch drive to be restored to normal after a predetermined time.

In another general aspect, there is provided a computer readable storage medium having stored thereon a computer program, characterized in that the computer program, when being executed by a processor, implements a method of fault pre-warning of a pitch drive as described above or a method of fault handling of a pitch drive as described above.

In another general aspect, there is provided a controller of a wind turbine generator set, the controller including: a processor; and a memory storing a computer program which, when executed by the processor, implements a fault pre-warning method for a pitch drive as described above or a fault handling method for a pitch drive as described above.

According to the fault early warning method and the fault early warning device of the variable pitch drive, starting from the working principle (namely, the voltage compensation/torque compensation) of the variable pitch drive, fault early warning can be carried out on the variable pitch drive 25-30 s in advance. During this time, there is sufficient time to complete the operation and control of the anti-seize paddle.

On the other hand, according to the fault processing method and the fault processing device of the variable pitch drive, due to the fact that the operation of restarting the variable pitch drive in a power-off mode is not needed, and the time for adjusting the output of the variable pitch drive can be set, the safety influence on the wind generating set is small, and the problem of brake contracting brake abrasion caused by restarting the variable pitch drive in the power-off mode is solved. On the other hand, the crosswind yawing is carried out after the pitch drive is determined to be in fault, so that the wind power borne by the blades of the wind generating set is reduced, the rotating speed is reduced, and then the determined pitch drive which is in fault is subjected to operation control such as adjustment of the output of the pitch drive and recovery of the normal output of the pitch drive, so that the safety of the wind generating set can be protected to the greater extent. In addition, whether the angles of the blades are consistent or not is judged, so that the increase of the load of the wind generating set caused by the inconsistency of the angles of the three blades after the variable pitch drive triggers the fault is facilitated to be reduced. Further, by adjusting the output of the pitch drive by reducing the given pitch speed provided to the pitch drive rather than temporarily setting the output of the pitch drive, delays caused by powering down to restart the pitch drive or suspending pitch drive operation may be reduced.

Additional aspects and/or advantages of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept.

Drawings

The above and other objects and features of the embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings illustrating embodiments, in which:

FIG. 1 is a diagram illustrating an example of a pitch system of a wind park according to an embodiment of the present disclosure;

FIG. 2 is a diagram illustrating an example of field operational data of a pitch motor;

FIG. 3 is a flow chart illustrating a fault warning method of a pitch drive according to an embodiment of the present disclosure;

FIG. 4 is a flow chart illustrating an example of a fault warning method of a pitch drive according to an embodiment of the present disclosure;

FIG. 5 is a flow chart illustrating another example of a fault warning method of a pitch drive according to an embodiment of the present disclosure;

FIG. 6 is a flow chart illustrating a fault handling method of a pitch drive according to an embodiment of the present disclosure;

FIG. 7 is a flow chart illustrating an example of a fault handling method of a pitch drive according to an embodiment of the present disclosure;

FIG. 8 is a flow chart illustrating another example of a fault handling method of a pitch drive according to an embodiment of the present disclosure;

FIG. 9 is a block diagram illustrating a fault early warning arrangement of a pitch drive according to an embodiment of the present disclosure;

FIG. 10 is a block diagram illustrating a fault handling arrangement of a pitch drive according to an embodiment of the present disclosure;

fig. 11 is a block diagram illustrating a controller of a wind park according to an embodiment of the present disclosure.

Detailed Description

The following detailed description is provided to assist the reader in obtaining a thorough understanding of the methods, devices, and/or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and/or systems described herein will be apparent to those skilled in the art after reviewing the disclosure of the present application. For example, the order of operations described herein is merely an example, and is not limited to those set forth herein, but may be changed as will become apparent after understanding the disclosure of the present application, except to the extent that operations must occur in a particular order. Moreover, descriptions of features known in the art may be omitted for clarity and conciseness.

The features described herein may be embodied in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein have been provided to illustrate only some of the many possible ways to implement the methods, devices, and/or systems described herein, which will be apparent after understanding the disclosure of the present application.

As used herein, the term "and/or" includes any one of the associated listed items and any combination of any two or more.

Although terms such as "first", "second", and "third" may be used herein to describe various elements, components, regions, layers or sections, these elements, components, regions, layers or sections should not be limited by these terms. Rather, these terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section referred to in the examples described herein could also be referred to as a second element, component, region, layer or section without departing from the teachings of the examples.

In the specification, when an element (such as a layer, region or substrate) is described as being "on," "connected to" or "coupled to" another element, it can be directly on, connected to or coupled to the other element or one or more other elements may be present therebetween. In contrast, when an element is referred to as being "directly on," "directly connected to," or "directly coupled to" another element, there may be no intervening elements present.

The terminology used herein is for the purpose of describing various examples only and is not intended to be limiting of the disclosure. The singular is also intended to include the plural unless the context clearly indicates otherwise. The terms "comprises," "comprising," and "having" specify the presence of stated features, quantities, operations, elements, components, 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.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs after understanding the present disclosure. Unless explicitly defined as such herein, terms (such as those defined in general dictionaries) should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and should not be interpreted in an idealized or overly formal sense.

Further, in the description of the examples, when it is considered that detailed description of well-known related structures or functions will cause a vague explanation of the present disclosure, such detailed description will be omitted.

The fault early warning system (FPS) utilizes original operation data in a storage system or equipment and converts the original operation data into a dynamic equipment online model under the support of a similar theory through technologies such as multiple regression, principal component analysis and the like in a data mining technology. And comparing the real-time estimated value generated by the calculation of the dynamic equipment model with the measured value of the equipment measuring point, and issuing early fault state early warning of the equipment according to the comparison result. Based on the reasons, the fault early warning method of the variable pitch drive is designed and used for early warning the fault of the variable pitch drive.

Fig. 1 is a diagram illustrating an example of a pitch system of a wind park according to an embodiment of the present disclosure.

Referring to fig. 1, the pitch system may include a pitch motor 101, a supercapacitor 102, a controller 103, a pitch drive 104, an enable switch (limit switch) 105, a brake relay 106, and an encoder 107.

When pitch drive 104 is operating normally, enable switch (limit switch) 105 is closed, and pitch drive 104 is powered. When controller 103 receives an indication of the pitch speed of the main controller of the wind park or controller 103 detects a failure of the pitch system and is autonomously feathered, controller 103 sends a speed command and an enable signal to pitch drive 104. After receiving the speed command and the enabling signal, the pitch control driver 104 controls the brake relay 106 to release the brake, and provides output voltage through power output to drive the pitch control motor 101 to rotate, so that the pitch control function is realized.

Encoder 107 may encode the change in pitch angle of the blades of the wind park and provide its value to pitch drive 104 and/or controller 103. Pitch drive 104 and/or controller 103 may calculate a rotational speed of pitch motor 101 based on the read encoder values. Pitch drive 104 compares the calculated rotational speed to the value of the speed command sent to pitch drive 104 by controller 103. If the calculated rotational speed is less than the value of the speed command, pitch drive 104 may increase the voltage of the power output to increase the rotational speed of pitch motor 101. If the calculated rotational speed is greater than the value of the speed command, pitch drive 104 may reduce the voltage of the power output to turn down the rotational speed of pitch motor 101. In this way, the rotational speed of pitch motor 101 can eventually be brought into agreement with the value of the given speed command.

The pitch controller 103 may control the overall operation of the pitch system and may communicate with the main control of the wind turbine generator system, receive control instructions sent by the main controller and/or send status information of the pitch system to the main controller. The pitch controller 103 may perform a fault pre-warning method and a fault handling method of the pitch drive according to embodiments of the present disclosure, which will be described later.

The working principle of the variable-pitch driver (also called a frequency converter) is as follows: in order to keep the magnetic flux of the variable pitch motor unchanged, the variable frequency and variable voltage are required. The condition that the frequency converter keeps the magnetic flux unchanged is as follows:

wherein f is_xThe operating frequency of a variable pitch motor is Hz; e_xIs at an operating frequency f_xWhen the motor is started, the self-induced electromotive force of one phase winding of the motor stator is in a unit of V.

However, due to the reasons of the operation efficiency of the variable pitch motor and the like, only the following conditions can be actually achieved:

wherein, U_xIs at an operating frequency f_xAnd when the output voltage is output to the variable pitch motor by the variable pitch driver, the unit is V. In other words, U_x/f_xEquation (2) is satisfied, and equation (1) is not really satisfied. The reason for this can be shown in equation (3).

T_m＝K_mΦ₁i₂cosφ₂ (3)

Wherein, T_mIs the electromagnetic torque of the pitch motor, K_mIs the torque coefficient, phi, of the pitch motor₁Is the magnetic flux of each pole of the pitch motor, cos phi₁Is the power factor at the rotor side of the pitch motor i₂Is the output current of the pitch motor.

In equation (3), i₂The rated current of the pitch motor is not allowed to be exceeded. Therefore, the load capacity of the pitch motor is mainly determined by the magnetic flux of the pitch motor. In the circuit of the stator winding of an asynchronous motor, U_xAnd E_xThe difference between them is mainly the voltage drop of the stator winding resistance, as shown in equation (4).

U_x＝-E_X+I₁r (4)

I₁Is the phase current of the stator; r is the resistance of a stator phase winding. Therefore, the magnitude of the magnetic flux is developed from equation (4) to equation (5).

And K phi is the magnetic flux coefficient of the variable pitch motor.

As can be seen from equation (5), since both the back-emf and the voltage are frequency dependent, the voltage drop Δ U is equal to I₁r is not frequency dependent, so when the pitch motor is at frequency f_xIn operation, the magnitude of the magnetic flux is related to the following factors.

First, the output voltage of the pitch drive (supply voltage of the pitch motor), U_xThe larger the magnetic flux. Second, the motor is lightly loaded. The heavier the load, the greater the current and the reduced flux. The resistive voltage drop accounts for a proportion of the supply voltage. Since the output voltage of the pitch drive is reduced when the operating frequency is reduced, but the resistive voltage drop is constant if the load torque is constant, the proportion of the resistive voltage drop in the supply voltage will increase, also resulting in a reduction of the magnetic flux.

Therefore, when the running state of the variable pitch motor or the variable pitch driver is abnormal, the load is increased, and the magnetic flux is reduced. If it is desired that the pitch drive is operated to obtain a rated flux, only the output voltage of the pitch drive is increased. This method of increasing the flux by properly compensating the voltage, thereby enhancing the loaded capacity of the pitch motor at low frequencies, is called voltage compensation, also called torque compensation. When the operating frequencies are different, the compensation amount of the voltage is different.

The method and the device utilize the characteristic of the running of the variable pitch driver to carry out online monitoring and analysis on the running data of the variable pitch system, so that the fault of the variable pitch driver is pre-warned before the fault is triggered by the variable pitch driver.

FIG. 2 is a diagram illustrating an example of field operational data of a pitch motor. Curve 201 indicates the pitch motor voltage for the normal axis, curve 202 indicates the pitch motor voltage for the abnormal axis, and curve 203 indicates the driver ok signal status for the abnormal axis. Here, the shaft may correspond to the blade. Optionally, the three blades each correspond to a shaft, each shaft having a pitch controller, a pitch drive, and a pitch motor. However, the present disclosure is not limited thereto.

Referring to fig. 2, the voltage of the pitch motor of the abnormal axis is obviously increased around-23 s, and a driver ok signal is a normal heartbeat signal (the period is 100 ms); at time 0s, the driver ok signal changes to a failed signal (period about 500ms, interval time greater than 2 s). Therefore, through the analysis of the operation mechanism of the variable pitch drive, the voltage of the variable pitch motor output by the variable pitch drive can be monitored in the operation process of the variable pitch drive, so that the fault of the variable pitch drive is early warned.

FIG. 3 is a flow chart illustrating a fault warning method of a pitch drive according to an embodiment of the disclosure.

According to the embodiment of the disclosure, the fault early warning method can be operated in each pitch control. However, the present disclosure is not limited thereto, and the fault pre-warning method may also be operated in a main controller of the wind turbine generator set or in other controllers. Alternatively, the fault pre-warning method may also be operated in a controller of the wind park or any other controller capable of communicating with the wind park.

Referring to fig. 3, in step S301, a theoretical pitch voltage of the pitch motor is calculated based on the operation data of the pitch motor. Here, the operational data of the pitch motor may comprise an actual pitch speed of the pitch motor and/or an operational frequency of the pitch motor. The actual pitch speed and/or the operating frequency of the pitch motor may be determined by encoder values provided by encoders in the pitch system. However, the present disclosure is not so limited, and the actual pitch speed and/or operating frequency of the pitch motor may be determined by any method.

Specifically, in step S301, the product of the actual pitch speed of the pitch motor and the operating frequency of the pitch motor may be calculated as the theoretical pitch voltage of the pitch motor. I.e. U-v x f, where U denotes the theoretical pitch voltage of the pitch motor, v denotes the actual pitch speed of the pitch motor, and f denotes the operating frequency of the pitch motor.

Optionally, in step S301, a theoretical pitch voltage corresponding to the actual pitch speed may be obtained according to the actual pitch speed of the pitch motor and a linear relationship obtained by fitting the historical theoretical pitch voltage of the pitch motor to the historical pitch speed. For example, curve fitting may be performed on the historical theoretical pitch voltage and the historical pitch speed of the pitch motor through an experimental method, and a linear relationship between the historical theoretical pitch voltage and the historical pitch speed is obtained as shown in an equation U + a + B X, where U represents the historical theoretical pitch voltage of the pitch motor, X represents the historical pitch speed of the pitch motor, and a and B are a first coefficient and a second coefficient obtained through curve fitting, respectively. Then, the actual pitch speed is used as X and substituted into the equation, and the theoretical pitch voltage U corresponding to the actual pitch speed can be calculated.

In step S302, an actual pitch voltage of the pitch motor may be acquired. Here, the voltage of the pitch motor may be detected by a voltage sensor provided on the pitch motor, or the voltage of the pitch motor may be detected by a voltage sensor provided on the pitch drive. However, the present disclosure is not limited thereto, and the voltage of the pitch motor may be detected in various ways. Alternatively, step S302 may be performed before step S301.

In step S303, it may be determined whether the pitch drive will fail based on the theoretical pitch voltage and the actual pitch voltage.

Specifically, in the case where the theoretical pitch voltage of the pitch motor is calculated by U ═ v × f, it may be determined whether the pitch drive will fail based on the magnitude relationship between the theoretical pitch voltage and the actual pitch voltage and the magnitude relationship between the actual pitch speed of the pitch motor and the given pitch speed. For example, it may be determined at this time first whether the actual pitch voltage is greater than N times the theoretical pitch voltage (U1> N × U, U1 representing the actual pitch voltage) for a threshold time. Here, N may be a real number greater than 1 (e.g., without limitation, N ═ 2). The threshold time may be, for example, but not limited to, 5 s. Indeed, when U1>2U reaches 5s (i.e. the actual pitch voltage of the pitch motor continues to increase), the magnetic flux of the pitch drive may be considered to decrease. And then, when the actual variable pitch voltage is greater than N times of the theoretical variable pitch voltage for the threshold time, determining whether the actual variable pitch speed of the variable pitch motor reaches the given variable pitch speed. Whether the variable pitch motor is normally started or not can be judged by determining whether the actual variable pitch speed of the variable pitch motor reaches the given variable pitch speed or not. If the actual pitch speed reaches the given pitch speed, it may be determined that the pitch drive will fail. In other words, if the actual pitch speed reaches the given pitch speed, it is said that the pitch motor is normally started. However, since the actual pitch voltage of the pitch motor is increased more and continuously at this time, it is indicated that the magnetic flux of the pitch drive has been reduced, and thus it can be finally assumed that the pitch drive will fail. More specifically, the purpose of detecting the pitch speed is to improve the accuracy of voltage consistency judgment of the pitch motor and fault early warning of the pitch driver, and the essence of the method is to detect that the magnetic flux of the pitch motor is reduced and increase the voltage output by the pitch driver.

Optionally, the theoretical pitch variation voltage corresponding to the actual pitch variation speed may be obtained according to the actual pitch variation speed of the pitch variation motor and a linear relation obtained by fitting the historical pitch variation voltage of the pitch variation motor and the historical pitch variation speed. For example, the linear relationship obtained by fitting the historical pitch voltage and the historical pitch speed of the pitch motor may be: and U is A + B X, so that the obtained actual pitch variation speed of the pitch variation motor is substituted into the linear equation to obtain the theoretical pitch variation voltage of the pitch variation motor at the actual pitch variation speed, and then whether the pitch variation driver fails or not is determined based on the size relation between the theoretical pitch variation voltage and the actual pitch variation voltage. For example, it may at this point be determined first whether the actual pitch voltage is greater than N times the theoretical pitch voltage for a threshold time. As described above, N may be a real number greater than 1 (e.g., without limitation, N ═ 2). The threshold time may be, for example, but not limited to, 5 s. Thereafter, it may be determined that the pitch drive will fail when the actual pitch voltage is greater than N times the theoretical pitch voltage for a threshold time.

According to the embodiment of the disclosure, before calculating the theoretical pitch voltage of the pitch motor, whether the output information of the pitch driver contains the magnetic flux information of the pitch motor can be determined. If the output information of the variable pitch drive comprises variable pitch motor magnetic flux information, whether the magnetic flux of the variable pitch motor is saturated or not can be determined, and when the magnetic flux of the variable pitch motor is saturated, the variable pitch drive can be determined to be in failure. Generally speaking, above 110%, the magnetic circuit begins to saturate and above 120% is already supersaturated. When the magnetic circuit is in a severe saturation state, the peak value of the exciting current can exceed several times of the rated current, and the output voltage of the magnetic circuit also rises, so that the over-current trip of the variable-pitch drive is caused.

In addition, the torque boost of the pitch drive can be obtained before the theoretical pitch voltage of the pitch motor is calculated, and when the torque boost of the pitch drive exceeds a preset threshold, it can be determined that the pitch drive will fail. For example, the upper limit value of the torque lift amount is generally 10%, but is not limited thereto.

Further, when it is determined that the pitch drive will fail, fault pre-warning information indicating that the pitch drive will fail may be provided to a main controller of the wind turbine. However, the present disclosure is not limited thereto. For example, the fault warning information may be processed directly by the pitch controller.

According to the fault early warning method of the variable pitch drive, starting from the working principle (namely, the voltage compensation/torque compensation) of the variable pitch drive, fault early warning can be carried out on the variable pitch drive 25-30 s in advance. During this time, there is sufficient time to complete the operation and control of the anti-seize paddle.

An example of a fault pre-warning method of a pitch drive according to an embodiment of the present disclosure is described below with reference to fig. 4 and 5.

FIG. 4 is a flow chart illustrating an example of a fault warning method of a pitch drive according to an embodiment of the present disclosure.

Referring to fig. 4, in step S401, a current shaft pitch motor voltage (i.e., an actual pitch voltage of the pitch motor) and a blade pitch speed (i.e., an actual pitch speed of the pitch motor) may be collected. As described above, the shaft may correspond to the blade. Optionally, the three blades correspond to a shaft, each shaft is provided with a pitch control cabinet, and a pitch control controller is arranged in the pitch control cabinet. In addition, each shaft is also provided with a variable pitch driver and a variable pitch motor. As mentioned above, the fault pre-warning method may be performed by a pitch controller.

In step S402, the operating frequency of the pitch drive may be collected, and the theoretical pitch voltage U ═ v × f of the pitch motor is calculated; v is the blade pitch speed (i.e. the actual pitch speed of the pitch motor) and f is the operating frequency of the pitch drive. The following table 1 shows the correspondence between the theoretical pitch voltage of the pitch motor and the operating frequency and pitch speed.

TABLE 1

In step S403, it is determined whether the actual pitch voltage U1 of the pitch motor is greater than N (e.g., N-2) times U for a predetermined time. If U1> N U, it may be preliminarily judged that pitch drive flux is decreasing and a fault will occur. On the other hand, if U1 ≦ N × U, or U1> N × U does not last for the predetermined time, it may be assumed that the pitch drive is not malfunctioning and the fault warning method is exited.

When U1> N × U lasts for a predetermined time, in step S404 it may be determined whether the actual pitch speed of the pitch motor reaches a given pitch speed.

If the actual pitch speed of the pitch motor reaches the given pitch speed, it may be determined in step S405 that the pitch drive will fail. As mentioned above, if the actual pitch speed reaches the given pitch speed, it indicates that the pitch motor is normally started. However, since the pitch drive flux has been determined to be reduced, it can be concluded that the pitch drive will fail if the actual pitch speed reaches a given pitch speed. On the other hand, if the actual pitch variation speed of the pitch variation motor does not reach the given pitch variation speed, the pitch variation driver can be finally determined not to have faults, and the fault early warning step is quitted.

According to an embodiment of the present disclosure, when it is determined in step S405 that the pitch drive will fail, the failure warning information may be provided to, for example, a main controller of the wind turbine generator system to process the failure warning information. However, the present disclosure is not limited thereto. And the fault early warning information can be directly processed by the variable pitch controller.

FIG. 5 is a flow chart illustrating another example of a fault warning method of a pitch drive according to an embodiment of the present disclosure.

Referring to fig. 5, in step S501, a current shaft pitch motor voltage (i.e., an actual pitch voltage of the pitch motor) and a blade pitch speed (i.e., an actual pitch speed of the pitch motor) may be collected.

Then, in step S502, a theoretical pitch voltage of the pitch motor may be calculated by an equation U + B X, where U denotes the theoretical pitch voltage of the pitch motor, X denotes an actual pitch speed of the pitch motor, B denotes a first coefficient, and a denotes a second coefficient. Here, the historical theoretical pitch voltage and the historical pitch speed of the pitch motor may be curve-fitted by an experimental method, so as to determine a linear relationship therebetween, that is, the above equation U is a + B X, where a and B are a first coefficient and a second coefficient obtained by curve-fitting, respectively. For example, a curve fit may be made with the given pitch speed shown in table 1 as the historical pitch speed and the theoretical pitch voltage shown in table 1 as the historical theoretical pitch voltage. In this case, a-35.33853004 and B-44.50517005 are optionally available.

Next, in step S503, it is determined whether the actual pitch voltage U1 of the pitch motor is greater than N (e.g., N-2) times U for a predetermined time. If U1> N U, then in step S504, it may be determined that the pitch drive will fail. On the other hand, if U1 ≦ N × U, or U1> N × U does not last for the predetermined time, it may be assumed that the pitch drive is not malfunctioning and the fault warning method is exited.

As described above, when it is determined in step S504 that the pitch drive will fail, the failure warning information may be provided to, for example, a main controller of the wind turbine generator set to process the failure warning information. However, the present disclosure is not limited thereto. And the fault early warning information can be directly processed by the variable pitch controller.

A fault handling method of a pitch drive according to an embodiment of the present disclosure is described in detail below with reference to fig. 6 to 8.

FIG. 6 is a flow chart illustrating a fault handling method of a pitch drive according to an embodiment of the present disclosure.

According to an embodiment of the present disclosure, the fault handling method may be run in a main controller or other controller of a wind turbine generator set. However, the present disclosure is not so limited and the fault handling method may also be operated in a controller of a wind park or in any other controller capable of communicating with a wind park.

Referring to FIG. 6, in step S601, the output of the pitch drive is adjusted in response to determining that the pitch drive will fail by the fault early warning method described above. For example, the output of the pitch drive may be adjusted when fault warning information is received. Here, adjusting the output of the pitch drive may include suspending the output of the pitch drive and adjusting the output of the pitch drive by reducing a given pitch speed provided to the pitch drive.

Then, in step S602, after a predetermined time has elapsed after adjusting the output of the pitch drive, the output of the pitch drive is controlled to return to normal. For example, the predetermined time may be set to 3s to 10s, but is not limited thereto.

Optionally, the fault handling method may further include the steps of: in response to determining that the pitch drive will fail by a fault pre-warning method as described above, it is determined whether the risk is avoidable. When it is determined that the risk is avoidable, the output of the pitch drive is adjusted. Specifically, the rotational speed of the wind turbine generator set and the wind speed at the location of the wind turbine generator set may be first detected, then it may be determined whether the detected rotational speed is less than a threshold rotational speed, and it may be determined whether the detected wind speed is less than a threshold wind speed. When it is determined that the detected rotational speed is less than the threshold rotational speed and the detected wind speed is less than the threshold wind speed, it is determined that the risk is avoidable. However, if it is determined that the risk is not avoidable, the fault handling method may be exited to control the wind park by other control strategies (e.g., without limitation, to control the wind park to shut down).

Optionally, the fault handling method may further include the steps of: responding to the fact that the variable pitch drive is determined to be in fault through the fault early warning method, and controlling the wind driven generator to yaw by a preset angle; detecting whether the rotating speed of the wind generating set is reduced or not; and when the reduction of the rotating speed of the wind generating set is detected, adjusting the output of the variable pitch driver. However, if it is detected that the rotational speed of the wind park has not dropped, the fault handling method may be exited to control the wind park by other control strategies (such as, but not limited to, controlling the wind park to shut down).

Optionally, the fault handling method may further include the steps of: determining whether the angle of each blade is consistent during the predetermined time in response to adjusting the output of the pitch drive; and controlling the wind generating set to stop in response to determining that the angles of the blades are inconsistent. In particular, the angle of the first blade that determines the moment at which the pitch drive will fail may be set to the reference angle value, wherein the first blade is the blade that corresponds to the determined pitch drive that will fail. Next, the sum of the reference angle value and the additional angle value may be used as an angle upper limit value, and the difference between the reference angle value and the additional angle value may be used as an angle lower limit value. Subsequently, it is monitored during the predetermined time whether the angles of the other blades exceed an angle threshold range defined by an angle upper limit value and an angle lower limit value. If the angle of any blade is monitored to be beyond the angle threshold range, the angle of each blade can be determined to be inconsistent, the fault handling method is exited, and the wind generating set is controlled to be stopped.

According to the fault processing method of the variable pitch driver, due to the fact that the operation of restarting the variable pitch driver after power failure is not needed, and the time for adjusting the output of the variable pitch driver can be set, the safety influence on the wind generating set is small, and the problem of brake contracting brake abrasion caused by restarting the variable pitch driver after power failure does not exist. On the other hand, the crosswind yawing is carried out after the pitch drive is determined to be in fault, so that the wind power borne by the blades of the wind generating set is reduced, the rotating speed is reduced, and then the determined pitch drive which is in fault is subjected to operation control such as adjustment of the output of the pitch drive and recovery of the normal output of the pitch drive, so that the safety of the wind generating set can be protected to the greater extent. In addition, whether the angles of the blades are consistent or not is judged, so that the increase of the load of the wind generating set caused by the inconsistency of the angles of the three blades after the variable pitch drive triggers the fault is facilitated to be reduced. Further, by adjusting the output of the pitch drive by reducing the given pitch speed provided to the pitch drive rather than temporarily setting the output of the pitch drive, delays caused by powering down to restart the pitch drive or suspending pitch drive operation may be reduced.

An example of a fault handling method of a pitch drive according to an embodiment of the present disclosure is described below with reference to fig. 7 and 8.

FIG. 7 is a flow chart illustrating an example of a fault handling method of a pitch drive according to an embodiment of the present disclosure.

Referring to fig. 7, in step S701, in response to receiving the fault warning information, a rotation speed of the wind turbine generator and a wind speed at a location where the wind turbine generator is located are detected.

In step S702, it is determined whether the risk is evasive based on the rotation speed of the wind turbine generator and the wind speed at the position where the wind turbine generator is located. As described above, the risk is determined to be avoidable when determining whether the detected rotational speed is less than the threshold rotational speed and the detected wind speed is less than the threshold wind speed.

When it is determined that the risk is avoidable, in step S703, the output of the pitch drive is suspended. And stopping the variable pitch motor by suspending the output of the determined variable pitch drive which is to have a fault, so as to wait for the condition causing the fault early warning to be eliminated. However, if it is determined that the risk is not avoidable, the fault handling method may be exited to control the wind park by other control strategies (e.g., without limitation, to control the wind park to shut down).

In step S704, the angle of the first blade at the moment when the pitch drive is determined to be about to fail is recorded as a reference angle value. As described above, the first blade is the blade corresponding to the determined pitch drive that will fail.

In step S705, it is monitored during a predetermined time whether the angles of the other blades exceed the pitch angle threshold range. Here, the pitch angle range threshold may be determined by using a sum of the reference angle value and the additional angle value as an upper angle limit value and a difference between the reference angle value and the additional angle value as a lower angle limit value. The additional angle value may be, for example, but not limited to, 3.5 degrees. Specifically, if the angle of the first blade (i.e., the reference angle value) at the time when the pitch drive is determined to be about to fail is 5.5 degrees, the upper limit of the pitch angle of the other two blades is 5.5+ 3.5-8 degrees, and the lower limit of the pitch angle is 5.5-3.5-2 degrees. Therefore, the other two blades can adjust the propeller within the propeller adjusting angle threshold range of 2-8 degrees, so that the rotating speed of the wind generating set is not over-speed.

If it is not detected that the angle of any blade exceeds the pitch angle threshold range, in step S706, the output of the pitch drive is restored, thereby restarting the pitch control of the corresponding blade. However, if the angle of any blade is detected to be beyond the angle threshold range, the fault handling method can be exited and the wind turbine generator set can be controlled to stop.

FIG. 8 is a flow chart illustrating another example of a fault handling method of a pitch drive according to an embodiment of the present disclosure.

Referring to fig. 8, in response to receiving the fault pre-warning information, the wind turbine is controlled to yaw by a preset angle in step S801.

In step S802, it is detected whether the rotation speed of the wind turbine generator system is reduced.

When a drop in the rotational speed of the wind turbine generator system is detected, in step S803, the output of the pitch drive is suspended. However, if it is detected that the rotational speed of the wind park has not dropped, the fault handling method may be exited to control the wind park by other control strategies (such as, but not limited to, controlling the wind park to shut down).

Next, in step S804, the angle of the first blade at the moment when the pitch drive is determined to be about to fail is recorded as a reference angle value. As described above, the first blade is the blade corresponding to the determined pitch drive that will fail.

In step S805, it is monitored during a predetermined time whether the angles of the other blades exceed the pitch angle threshold range. As described above, the pitch angle range threshold may be determined by using the sum of the reference angle value and the additional angle value as the angle upper limit value and the difference between the reference angle value and the additional angle value as the angle lower limit value.

If it is not detected that the angle of any blade exceeds the pitch angle threshold range, in step S806, the output of the pitch drive is restored, thereby restarting the pitch control of the corresponding blade. However, if the angle of any blade is detected to be beyond the angle threshold range, the fault handling method can be exited and the wind turbine generator set can be controlled to stop.

FIG. 9 is a block diagram illustrating a fault early warning arrangement of a pitch drive according to an embodiment of the present disclosure.

As described above, the three blades of the wind turbine generator system correspond to one shaft, each having a pitch controller, a pitch drive, and a pitch motor. Accordingly, each pitch controller may be provided with a fault pre-warning device of the pitch drive according to embodiments of the present disclosure. However, the present disclosure is not limited thereto, and the fault pre-warning device of the pitch drive according to embodiments of the present disclosure may be provided in the main controller of the wind turbine generator set or in other controllers.

Referring to fig. 9, the fault pre-warning apparatus 900 may include a voltage calculation unit 910, a voltage acquisition unit 920, and a fault pre-warning unit 930. The voltage calculating unit 910 may calculate a theoretical pitch voltage of the pitch motor based on the operation data of the pitch motor. The operational data of the pitch motor may comprise an actual pitch speed of the pitch motor and/or an operational frequency of the pitch motor. The voltage obtaining unit 920 may obtain an actual pitch voltage of the pitch motor. The fault pre-warning unit 930 may determine whether the pitch drive will fail based on the theoretical pitch voltage and the actual pitch voltage.

Specifically, the voltage calculating unit 910 may calculate a product of an actual pitch speed of the pitch motor and an operating frequency of the pitch motor as a theoretical pitch voltage of the pitch motor. I.e. U-v x f, where U denotes the theoretical pitch voltage of the pitch motor, v denotes the actual pitch speed of the pitch motor, and f denotes the operating frequency of the pitch motor. Optionally, the voltage calculating unit 910 may obtain a theoretical pitch voltage corresponding to the actual pitch speed according to the actual pitch speed of the pitch motor and a linear relationship obtained by fitting the historical pitch voltage of the pitch motor to the historical pitch speed. Namely, U is a + B X, where U represents a theoretical pitch voltage of the pitch motor, X represents an actual pitch speed of the pitch motor, and a and B are a first coefficient and a second coefficient obtained by fitting.

Under the condition that the theoretical pitch voltage of the pitch motor is calculated through U ═ v × f, the fault early warning unit 930 may determine whether the pitch driver will fail based on the magnitude relationship between the theoretical pitch voltage and the actual pitch voltage and the magnitude relationship between the actual pitch speed of the pitch motor and the given pitch speed. More specifically, the fault pre-warning unit 930 may determine whether the actual pitch voltage is greater than N times the theoretical pitch voltage for a threshold time, where N is a real number greater than 1. When the actual pitch voltage is greater than N times the theoretical pitch voltage for the duration threshold time, the fault early warning unit 930 may determine whether the actual pitch speed of the pitch motor reaches a given pitch speed. If the actual pitch speed reaches the given pitch speed, the fault early warning unit 930 may determine that the pitch drive will have a fault, and send out early warning information to perform early warning.

Alternatively, in the case that the theoretical pitch voltage of the pitch motor is calculated by U ═ a + B ×, the fault early warning unit 930 may determine whether the pitch drive will fail based on the magnitude relationship between the theoretical pitch voltage and the actual pitch voltage. More specifically, the fault pre-warning unit 930 may determine whether the actual pitch voltage is greater than N times the theoretical pitch voltage for a threshold time, where N is a real number greater than 1. When the actual pitch voltage is greater than N times the theoretical pitch voltage for the threshold duration, the fault early warning unit 930 may determine that the pitch drive will fail.

According to the embodiment of the present disclosure, the fault early warning unit 930 may determine whether the output information of the pitch drive includes the magnetic flux information of the pitch motor before calculating the theoretical pitch voltage of the pitch motor. If the output information of the pitch drive comprises the magnetic flux information of the pitch motor, the fault early warning unit 930 may determine whether the magnetic flux of the pitch motor is saturated, and when the magnetic flux of the pitch motor is saturated, the fault early warning unit 930 may determine that the pitch drive will break down. In addition, the fault early warning unit 930 may obtain a torque boost amount of the pitch drive before calculating a theoretical pitch voltage of the pitch motor, and when the torque boost amount of the pitch drive exceeds a preset threshold, the fault early warning unit 930 may determine that the pitch drive will malfunction. Further, when it is determined that the pitch drive will fail, the fault pre-warning unit 930 may provide fault pre-warning information indicating that the pitch drive will fail to the main controller of the wind turbine.

FIG. 10 is a block diagram illustrating a fault handling arrangement of a pitch drive according to an embodiment of the present disclosure.

As described above, the three blades of the wind turbine generator system correspond to one shaft, each having a pitch controller, a pitch drive, and a pitch motor. Accordingly, each pitch controller may be provided with a fault handling arrangement of the pitch drive according to embodiments of the present disclosure. However, the present disclosure is not limited thereto, and the fault handling arrangement of the pitch drive according to embodiments of the present disclosure may be provided in the main controller of the wind park or in other controllers.

Referring to fig. 10, a fault handling apparatus 1000 of a pitch drive according to an embodiment of the present disclosure may include an output adjustment unit 1010 and an output restoration unit 1020. The output adjustment unit 1010 may adjust the output of the pitch drive in response to the fault pre-warning device determining that the pitch drive will fail as described above. Adjusting the output of the pitch drive can include suspending the output of the pitch drive and adjusting the output of the pitch drive by reducing a given pitch speed provided to the pitch drive. The output restoration unit 1020 may control the output of the pitch drive to be restored to normal after a predetermined time.

In particular, in response to determining that the pitch drive will fail by means of a fault pre-warning device as described above, the output adjustment unit 1010 may determine whether the risk is avoidable. When it is determined that the risk is avoidable, the output adjustment unit 1010 may adjust the output of the pitch drive. More specifically, the output adjustment unit 1010 may first detect a rotation speed of the wind turbine generator set and a wind speed at a location where the wind turbine generator set is located, then determine whether the detected rotation speed is less than a threshold rotation speed, and determine whether the detected wind speed is less than a threshold wind speed. When it is determined that the detected rotational speed is less than the threshold rotational speed and the detected wind speed is less than the threshold wind speed, the output adjustment unit 1010 determines that the risk is evasive.

Alternatively, in response to determining that the pitch drive will fail through the failure early warning device as described above, the output adjustment unit 1010 may control the wind turbine to yaw by a preset angle, detect whether the rotational speed of the wind turbine generator decreases, and adjust the output of the pitch drive when the rotational speed of the wind turbine generator decreases is detected.

Alternatively, in response to adjusting the output of the pitch drive, the output adjustment unit 1010 may determine whether the angles of the respective blades are consistent during the predetermined time; and controlling the wind generating set to stop in response to determining that the angles of the blades are inconsistent. Further, the output adjusting unit 1010 may set an angle of a first blade at a time when the pitch drive is determined to be in a failure as a reference angle value, where the first blade is a blade corresponding to the determined pitch drive that is determined to be in the failure. Next, the output adjusting unit 1010 may use the sum of the reference angle value and the additional angle value as an angle upper limit value, and use the difference between the reference angle value and the additional angle value as an angle lower limit value. Subsequently, the output adjustment unit 1010 may monitor whether the angles of the other blades exceed an angle threshold range defined by an angle upper limit value and an angle lower limit value during the predetermined time. If the angle of any blade is monitored to be beyond the angle threshold range, the output adjusting unit 1010 can determine that the angles of the blades are inconsistent, and accordingly the wind generating set is controlled to stop.

Referring to fig. 11, a controller 1100 of a wind park according to an embodiment of the present disclosure may be, but is not limited to, a pitch controller, a main controller of the wind park, etc. As described above, the three blades of the wind turbine generator system correspond to one shaft, each having a pitch controller, a pitch drive, and a pitch motor. The controller 1100 of a wind park according to an embodiment of the present disclosure may comprise a processor 1110 and a memory 1120. The processor 1110 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), and the like. The memory 1120 stores computer programs to be executed by the processor 1110. The memory 1120 includes high-speed random access memory and/or non-volatile computer-readable storage media. When processor 1110 executes a computer program stored in memory 1120, a method of fault early warning or a method of fault handling of a pitch drive as described above may be implemented.

Alternatively, the controller 1100 may communicate with other components in the wind park in wired/wireless communication, and may also communicate with other devices in the wind park in wired/wireless communication. Further, the controller 1100 may communicate with a device external to the wind farm in a wired/wireless communication manner.

The fault pre-warning method of a pitch drive and the fault handling method of a pitch drive according to embodiments of the present disclosure may be written as a computer program and stored on a computer readable storage medium. The computer program, when executed by a processor, may implement a method of fault pre-warning or a method of fault handling of a pitch drive as described above. 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 compact disc memory, Hard Disk Drive (HDD), solid-state drive (SSD), card-type memory (such as a multimedia card, a Secure Digital (SD) card or a extreme digital (XD) card), magnetic tape, a floppy disk, a magneto-optical data storage device, an optical data storage device, a hard disk, a magnetic tape, a magneto-optical data storage device, a hard disk, a magnetic tape, a magnetic data storage device, a magnetic tape, a magnetic data storage device, a magnetic tape, a magnetic data storage device, a magnetic tape, a magnetic data storage device, a magnetic tape, a magnetic data storage device, A solid state disk, and any other device configured to store and provide a computer program and any associated data, data files, and data structures to a processor or computer in a non-transitory manner such that the processor or computer can execute the computer program. In one example, the computer program and any associated data, data files, and data structures are distributed across networked computer systems such that the computer program and any associated data, data files, and data structures are stored, accessed, and executed in a distributed fashion by one or more processors or computers.

Although a few embodiments of the present disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.

Claims

1. A fault early warning method for a variable pitch drive is characterized by comprising the following steps:

calculating theoretical variable pitch voltage of the variable pitch motor based on the operation data of the variable pitch motor;

acquiring actual variable pitch voltage of a variable pitch motor; and

determining whether the pitch drive will fail based on the theoretical pitch voltage and the actual pitch voltage.

2. The fault pre-warning method according to claim 1, wherein the operational data comprises an actual pitch speed of a pitch motor and/or an operational frequency of the pitch motor.

3. The fault pre-warning method according to claim 2, wherein the step of calculating the theoretical pitch voltage of the pitch motor comprises: and calculating the product of the actual variable pitch speed of the variable pitch motor and the operating frequency of the variable pitch motor to be used as the theoretical variable pitch voltage of the variable pitch motor.

4. The fault pre-warning method according to claim 2, wherein the step of calculating the theoretical pitch voltage of the pitch motor comprises:

and acquiring theoretical variable pitch voltage corresponding to the actual variable pitch speed according to the actual variable pitch speed of the variable pitch motor and a linear relation obtained by fitting the historical variable pitch voltage of the variable pitch motor and the historical variable pitch speed.

5. The fault pre-warning method of claim 3, wherein the step of determining whether the pitch drive will fail based on the theoretical pitch voltage and the actual pitch voltage comprises: and determining whether the variable pitch driver fails or not based on the size relationship between the theoretical variable pitch voltage and the actual variable pitch voltage and the size relationship between the actual variable pitch speed of the variable pitch motor and the given variable pitch speed.

6. The fault alerting method of claim 5, wherein the step of determining whether the pitch drive will fail comprises:

determining whether the actual variable pitch voltage is greater than N times of the theoretical variable pitch voltage for a threshold time, wherein N is a real number greater than 1;

when the actual variable pitch voltage is longer than N times of the theoretical variable pitch voltage lasting threshold time, determining whether the actual variable pitch speed of the variable pitch motor reaches a given variable pitch speed;

if the actual pitch speed reaches the given pitch speed, it is determined that the pitch drive will fail.

7. The fault pre-warning method of claim 4, wherein the step of determining whether the pitch drive will fail based on the theoretical pitch voltage and the actual pitch voltage comprises: and determining whether the variable pitch driver is about to fail or not based on the size relation between the theoretical variable pitch voltage and the actual variable pitch voltage.

8. The fault alerting method of claim 7, wherein the step of determining whether a pitch drive will fail comprises:

and when the actual variable pitch voltage is greater than N times of the theoretical variable pitch voltage for the duration threshold time, determining that the variable pitch driver has a fault.

9. The fault early warning method of claim 1, further comprising:

before calculating the theoretical variable pitch voltage of the variable pitch motor, whether the magnetic flux of the variable pitch motor is saturated or not is determined based on the magnetic flux information of the variable pitch motor contained in the output information of the variable pitch driver, and the variable pitch driver is determined to be in failure in response to the magnetic flux of the variable pitch motor being saturated.

10. The fault early warning method of claim 1, further comprising:

before calculating the theoretical variable pitch voltage of the variable pitch motor, acquiring the torque lifting amount of the variable pitch driver, and determining that the variable pitch driver fails in response to the fact that the torque lifting amount of the variable pitch driver exceeds a preset threshold value.

11. A fault handling method of a pitch drive, the fault handling method comprising:

adjusting the output of the pitch drive in response to determining that the pitch drive will fail by a fault early warning method as claimed in any one of claims 1 to 10; and

after a predetermined time, the output of the pitch drive is controlled to return to normal.

12. The fault handling method of claim 11, wherein the fault handling method further comprises:

determining whether a risk is avoidable in response to determining that a pitch drive will fail by a fault pre-warning method as claimed in any of claims 1 to 10;

in response to determining that the risk is avoidable, performing the step of adjusting the output of the pitch drive.

13. The fault handling method of claim 12 wherein the step of determining whether the risk is avoidable comprises:

detecting the rotating speed of the wind generating set and the wind speed of the position where the wind generating set is located;

determining whether the detected rotational speed is less than a threshold rotational speed and determining whether the detected wind speed is less than a threshold wind speed;

in response to determining that the detected rotational speed is less than the threshold rotational speed and the detected wind speed is less than the threshold wind speed, determining that the risk is avoidable.

14. The fault handling method of claim 11, wherein the fault handling method further comprises:

controlling the wind turbine to yaw by a preset angle in response to determining that the pitch drive will fail by a fault pre-warning method according to any one of claims 1 to 10;

detecting whether the rotating speed of the wind generating set is reduced or not;

in response to detecting a drop in the rotational speed of the wind turbine generator system, the step of adjusting the output of the pitch drive is performed.

15. The fault handling method of claim 11, wherein adjusting the output of the pitch drive: including pausing the output of the pitch drive.

16. The fault handling method of claim 11, wherein adjusting the output of the pitch drive comprises: the output of the pitch drive is adjusted by reducing a given pitch speed provided to the pitch drive.

17. The fault handling method of claim 11, wherein the fault handling method further comprises:

determining whether the angle of each blade is consistent during the predetermined time in response to adjusting the output of the pitch drive;

and controlling the wind generating set to stop in response to determining that the angles of the blades are inconsistent.

18. The fault handling method of claim 17 wherein the step of determining whether the angles of the respective blades are consistent during the predetermined time comprises:

setting the angle of a first blade at the moment when the variable pitch drive is determined to be in fault as a reference angle value, wherein the first blade is the blade corresponding to the determined variable pitch drive which is to be in fault;

taking the sum of the reference angle value and the additional angle value as an upper angle limit value, and taking the difference between the reference angle value and the additional angle value as a lower angle limit value;

monitoring whether the angles of other blades exceed an angle threshold range defined by an angle upper limit value and an angle lower limit value during the predetermined time;

in response to monitoring that the angle of any of the blades is outside of the angle threshold range, determining that the angles of the blades are not consistent.

19. A fault pre-warning device of a pitch drive, the fault pre-warning device comprising:

the voltage calculation unit is configured to calculate a theoretical variable pitch voltage of the variable pitch motor based on the operation data of the variable pitch motor;

the voltage acquisition unit is configured to acquire an actual variable pitch voltage of the variable pitch motor; and

a fault early warning unit configured to determine whether the pitch drive will fail based on the theoretical pitch voltage and the actual pitch voltage.

20. A fault handling apparatus of a pitch drive, the fault handling apparatus comprising:

an output adjustment unit configured to adjust an output of the pitch drive in response to the fault pre-warning device of claim 19 determining that the pitch drive will fail; and

and the output recovery unit is configured to control the output of the pitch drive to recover to normal after a preset time.

21. A computer-readable storage medium, in which a computer program is stored which, when being executed by a processor, carries out a method for fault pre-warning of a pitch drive according to any one of claims 1 to 10 or a method for fault handling of a pitch drive according to any one of claims 11 to 18.

22. A controller for a wind turbine generator set, the controller comprising:

a processor; and

a memory storing a computer program which, when executed by the processor, implements a method of fault pre-warning of a pitch drive according to any of claims 1 to 10 or a method of fault handling of a pitch drive according to any of claims 11 to 18.