Torque determination method and torque determination device for a variable pitch motor

Abstract

A method and apparatus for determining the torque of a pitch motor are disclosed. The torque determination method includes: obtaining the rotational speed of the pitch motor at the end of the current calculation cycle; determining whether the obtained rotational speed of the pitch motor meets the torque calculation requirements; and, in response to the obtained rotational speed of the pitch motor meeting the torque calculation requirements, determining the actual torque of the pitch motor based on the pre-calculated actual torque of the pitch motor under standard operating conditions of a laboratory loading platform, the current calculation cycle, and the obtained rotational speed of the pitch motor.

Description

Technical Field

[0001] This disclosure generally relates to the field of wind power generation technology, and more specifically, to a method and apparatus for determining the torque of a pitch motor in a wind turbine generator set. Background Technology

[0002] With the gradual expansion of wind turbine scale and the increasing sophistication of turbine safety protection, the power generation performance of wind turbines—that is, improving the power generation and availability of wind turbines—has received increasing attention. On the other hand, while pursuing power generation efficiency, it is also crucial to strictly ensure the safety of wind turbines.

[0003] When a wind turbine generator malfunctions, on the one hand, the power industry's work permit system must be strictly followed, and some turbines may be located far away, requiring time to reach their locations; but most importantly, because a wind turbine generator is a complex system, MW-class permanent magnet wind turbines currently integrate aerodynamics, structural mechanics, electrical machinery, materials science, power electronics, power system analysis, relay protection technology, automatic control technology, and modern communications, becoming a complex energy conversion system. Therefore, the same fault may be caused by different reasons. For example, taking the "three-axis angle inconsistency" fault in the pitch system as an example, the cause of this fault may be a fault in the encoder itself, a fault in the encoder power supply, a stuck pitch in the pitch system, a fault in the drive, or even a fault in the controller's data acquisition module.

[0004] Analyzing the operating characteristics of wind turbine generators requires substantial data to ensure the accuracy of the analysis and statistics, thereby providing a reference for turbine design. For the pitch system of a wind turbine generator, the main power source for pitch control is the pitch motor, and changes in wind speed and the frequency of pitch control are reflected in the pitch motor. Therefore, calculating and analyzing the torque value of the pitch motor is of significant practical importance for a deeper understanding of the operating mechanism of the pitch system, as well as for pitch motor selection, toothed belt selection, brake solenoid valve selection, control strategy comparison, and optimization.

[0005] To facilitate simple and reasonable pitch motor selection, this paper derives calculation formulas for motor torque under different operating modes based on an analysis of the force transmission of the pitch motor and pitch bearings. A simulation model is then built in Bladed software to perform load calculations. Analysis of the calculated load data yields the maximum drive torque, rated torque, and maximum braking torque of the pitch motor, providing a reference for pitch motor selection. However, most pitch systems lack torque acquisition and calculation devices, making it difficult to calculate the pitch motor's torque value.

[0006] Existing methods for calculating the torque of pitch motors generally use the formula T = 9550p / n, where T is the motor torque, p is the motor power, and n is the motor speed. However, this method has the following shortcomings.

[0007] First, this formula is generally used for calculating the electromagnetic torque of a generator. The power p of a pitch motor can only be calculated using the motor voltage U and the motor current I. However, the power factor of a pitch motor is uncertain at different speeds. In addition, the pitch motor has a certain efficiency in its conversion, and the power of a pitch motor is generally only a few kilowatts, which is relatively small. The influence of the coefficient will be quite obvious. Therefore, the torque value calculated by this method is not accurate.

[0008] Secondly, during pitch adjustment, the motor current is constantly changing and fluctuating. Furthermore, the current value becomes unstable due to variations in blade azimuth, making it difficult to achieve high accuracy. Additionally, at lower pitch motor speeds, when the denominator in the formula T=9550p / n is small, the error is even greater. Even slight data fluctuations can lead to abnormal calculations, and since low speeds are the primary statistical target for load calculations, it is difficult to avoid significant errors in the calculated torque value.

[0009] Secondly, some pitch drives fail to transmit the pitch motor voltage and current to the pitch controller, or fail to record them in the data file. In this case, the absence of either the pitch motor voltage or the pitch motor current will prevent the calculation of the torque value. Summary of the Invention

[0010] The embodiments of this disclosure provide a method and apparatus for determining the torque of a pitch motor. When calculating the torque of a pitch motor, the voltage and current of the pitch motor are not required, nor are factors such as the power factor and mechanical efficiency of the pitch motor involved. Therefore, the accuracy of torque calculation can be improved, and the universality of pitch motor torque calculation can be achieved.

[0011] In one general aspect, a method for determining the torque of a pitch motor is provided, the method comprising: obtaining the rotational speed of the pitch motor at the end of the current calculation cycle, wherein the rotational speed of the pitch motor at the start of the current calculation cycle is 0; determining whether the obtained rotational speed of the pitch motor meets the torque calculation requirements; and, in response to the obtained rotational speed of the pitch motor meeting the torque calculation requirements, determining the actual torque of the pitch motor based on the pre-calculated actual torque of the pitch motor under standard operating conditions of a laboratory loading platform, the current calculation cycle, and the obtained rotational speed of the pitch motor.

[0012] In another general aspect, a torque determination device for a pitch motor is provided, the torque determination device comprising: a speed acquisition module configured to acquire the speed of the pitch motor at the end of the current calculation cycle, wherein the speed of the pitch motor at the start of the current calculation cycle is 0; a calculation requirement determination module configured to determine whether the acquired speed of the pitch motor meets the torque calculation requirements; and a torque determination module configured to, in response to the acquired speed of the pitch motor meeting the torque calculation requirements, determine the actual torque of the pitch motor based on a pre-calculated actual torque of the pitch motor under standard operating conditions of a laboratory loading platform, the current calculation cycle, and the acquired speed of the pitch motor.

[0013] In another general aspect, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the torque determination method for a pitch motor as described above.

[0014] 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 torque determination method for a pitch motor as described above.

[0015] The pitch motor torque determination method according to embodiments of this disclosure does not require the use of the pitch motor's voltage or current, nor does it involve factors such as power factor or motor mechanical efficiency. Therefore, it can improve the accuracy of torque calculation and achieve universality in pitch motor torque calculation. Furthermore, the pitch motor torque determination method according to embodiments of this disclosure can effectively calculate the stall torque of the pitch motor, thereby providing sufficient basis for pitch motor selection.

[0016] 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

[0017] 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:

[0018] Figure 1 This is a diagram illustrating an example of a pitch system for a wind turbine generator set according to an embodiment of the present disclosure;

[0019] Figure 2 This is a flowchart illustrating a method for determining the torque of a pitch motor according to an embodiment of the present disclosure;

[0020] Figure 3A This is a flowchart illustrating an example of a method for determining whether the acquired speed of the pitch motor meets the torque calculation requirements;

[0021] Figure 3B This is a flowchart illustrating another example of a method for determining whether the acquired speed of the pitch motor meets the torque calculation requirements;

[0022] Figure 4 This is a block diagram illustrating a torque determination device for a pitch motor according to an embodiment of the present disclosure;

[0023] Figure 5 This is a block diagram illustrating a controller for a wind turbine generator set according to an embodiment of the present disclosure. Detailed Implementation

[0024] 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.

[0025] 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.

[0026] As used herein, the term “and / or” includes any one of the associated listed items and any combination of any two or more.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] Figure 1 This is a diagram illustrating an example of a pitch system for a wind turbine generator according to an embodiment of the present disclosure.

[0033] Reference Figure 1 The pitch system may include a pitch motor 101, a supercapacitor 102, a pitch controller 103, a pitch driver 104, an enable switch (limit switch) 105, and a brake relay 106.

[0034] When the pitch drive 104 is operating normally, the enable switch (limit switch) 105 is closed, energizing the pitch drive 104. When the pitch controller 103 receives a pitch speed instruction from the wind turbine's main controller, or when the pitch controller 103 detects a fault in the pitch system and autonomously feathers the pitch, it sends a speed command and an enable signal to the pitch drive 104. Upon receiving the speed command and enable signal, the pitch drive 104 controls the brake relay 106 to release, and provides output voltage through the power output 108 to drive the pitch motor 101 to rotate, thus achieving the pitch adjustment function.

[0035] An encoder (not shown) located at the pitch motor 101 encodes the pitch angle change of the wind turbine blades and provides its value to the pitch driver 104 (e.g., via encoder interface 107) and / or the pitch controller 103. The pitch driver 104 and / or the pitch controller 103 calculate the rotational speed of the pitch motor 101 based on the read encoder value. The pitch driver 104 compares the calculated rotational speed with the speed command sent by the pitch controller 103. If the calculated rotational speed is less than the speed command value, the pitch driver 104 increases the voltage of the power output 108 to increase the rotational speed of the pitch motor 101. If the calculated rotational speed is greater than the speed command value, the pitch driver 104 decreases the voltage of the power output 108 to decrease the rotational speed of the pitch motor 101. This ultimately allows the rotational speed of the pitch motor 101 to match the value of the given speed command.

[0036] The pitch drive 104 can detect the status of external electrical components and stop power output 108 if a fault is triggered. The main faults involved are: if the brake relay 106 fails to open (release the brake), the pitch motor 101 will stall, triggering fault number 244 in the pitch drive 104. When the pitch motor 101 stalls, its output torque will be very large because it needs to maintain a given target speed. Therefore, accurately determining the pitch motor's torque is extremely important.

[0037] The pitch controller 103 controls the overall operation of the pitch system and can communicate with the main controller of the wind turbine generator set, receiving control commands from the main controller and / or sending status information of the pitch system to the main controller. The pitch controller 103 can execute the torque determination method for the pitch motor according to embodiments of this disclosure, as described below.

[0038] The principle of the torque determination method for a pitch motor according to embodiments of the present disclosure is explained below.

[0039] According to the laws of mechanics, there exists formula (1): ,in, This indicates the output force of the pitch motor. It is the equivalent mass of the pitch motor during rotation, and it is a constant value. It is the acceleration of the pitch motor. To elaborate further, let's assume... The pitch motor torque is equal to the product of the pitch motor's output force and its torsional radius. Since the pitch motor's radius is a fixed value, the torsional radius can be eliminated in the following calculations. Therefore, with the initial rotational speed at 0, according to the mechanical formula... Finally, the torque formula (2) can be obtained: That is, to obtain the time of change of pitch speed. t This allows us to determine the corresponding pitch motor torque. Therefore, when using the laboratory loading platform, the torque of the pitch motor satisfies formula (3): ,in, F 1 represents the actual torque of the pitch motor of the laboratory loading platform under standard operating conditions. t 1 represents the actual acceleration time of the pitch motor on the laboratory loading platform under standard operating conditions. v 1 represents the actual rotational speed of the pitch motor on the laboratory loading platform under standard operating conditions. During actual operation of the wind turbine generator set, the torque of the pitch motor satisfies equation (4): ,in, F 2 represents the actual torque of the pitch motor during operation. v 2 indicates the actual operating speed of the pitch motor. t 2 represents the acceleration time during actual operation of the pitch motor. Therefore, based on equations (3) and (4), the calculation formula (5) for the torque of the pitch motor during actual operation can be determined: .

[0040] For example, when the laboratory loading platform is loaded with a torque of 100 Nm under standard operating conditions, the pitch motor's speed increases from 0 degrees / second to 6 degrees / second in 0.6 seconds. When the pitch motor is actually running, its speed increases from 0 degrees / second to 2 degrees / second in 0.5 seconds. Therefore, the torque of the pitch motor during actual operation can be calculated as follows: .

[0041] The principle of the pitch motor torque determination method according to the embodiments of the present disclosure has been described above. The specific implementation of the pitch motor torque determination method according to the embodiments of the present disclosure is described below.

[0042] Figure 2 This is a flowchart illustrating a method for determining the torque of a pitch motor according to an embodiment of the present disclosure.

[0043] According to embodiments of this disclosure, the pitch motor torque determination method can be operated in each pitch controller of a wind turbine generator set. However, this disclosure is not limited thereto; the pitch motor torque determination method can also be operated in the main controller of the wind turbine generator set or in other controllers. Alternatively, the pitch motor torque determination method can also be operated in the controller of the wind farm or in any other controller capable of communicating with the wind turbine generator set.

[0044] Reference Figure 2In step S201, the pitch motor speed v2 at the end of the current calculation period T can be obtained. Here, the pitch motor speed at the start of the current calculation period T can be 0, and the length of the calculation period T can be arbitrarily set according to actual needs. For example, the length of the calculation period T can range from 20ms to 60ms, but is not limited to this. Furthermore, the pitch motor speed v2 at the end of the current calculation period T can be calculated based on the encoder value as described above. However, this disclosure is not limited to this; the pitch motor speed v2 at the end of the current calculation period T can also be obtained by setting a dedicated sensor or using other methods, and this disclosure does not impose any restrictions on this.

[0045] Next, in step S202, it can be determined whether the acquired pitch motor speed v2 meets the torque calculation requirements. By executing step S202, data (i.e., speed) fluctuations caused by encoder jumps, communication interruptions, encoder data acquisition module malfunctions, etc., can be effectively eliminated. (See below for further details.) Figure 3A and Figure 3B The specific steps are described in detail in step S202.

[0046] In step S203, in response to the acquisition of the pitch motor's rotational speed satisfying the torque calculation requirements, the actual torque of the pitch motor can be determined based on the pre-calculated actual torque F1 of the pitch motor under standard operating conditions of the laboratory loading platform, the current calculation period T, and the acquired pitch motor rotational speed v2. Here, the actual torque of the pitch motor under standard operating conditions of the laboratory loading platform can be calculated based on the equivalent mass m of the pitch motor during rotation, the actual acceleration time t1 of the pitch motor under standard operating conditions of the laboratory loading platform, and the actual rotational speed v1 of the pitch motor.

[0047] Specifically, in step S203, the actual torque of the pitch motor can be determined based on the actual torque F1 of the pitch motor under standard operating conditions of the laboratory loading platform, the actual acceleration time t1 of the pitch motor, the actual speed v1 of the pitch motor, the current calculation period T, and the obtained speed v2 of the pitch motor. More specifically, the first value can be calculated by dividing the obtained speed v2 of the pitch motor by the current calculation period T. Then, the second value can be calculated by dividing the actual speed v1 of the pitch motor under standard operating conditions by the actual acceleration time t1. The third value can then be calculated by dividing the first and second values. Finally, the actual torque of the pitch motor under standard operating conditions is determined by the product of the third value and the actual torque of the pitch motor. That is, the actual torque of the pitch motor = F1. (v2 / T) / (v1 / t1).

[0048] As described above, the pitch motor torque determination method according to the embodiments of this disclosure does not require the use of the pitch motor's voltage or current, nor does it involve factors such as power factor or motor mechanical efficiency. Therefore, it can improve the accuracy of torque calculation and achieve universality in pitch motor torque calculation. On the other hand, the pitch motor torque determination method according to the embodiments of this disclosure can be applied to the statistical calculation of torque values ​​for any type of pitch motor, and can guarantee the calculation accuracy of low-speed data, solving the problem of inaccurate pitch motor torque calculation at low speeds. Furthermore, the pitch motor torque determination method according to the embodiments of this disclosure is independent of the forward and backward positions of the blade angle, and only related to the angle change process and duration, thereby reducing its computational complexity. In addition, the pitch motor torque determination method according to the embodiments of this disclosure uses the actual torque of a laboratory loading platform under standard operating conditions, thus ensuring the accuracy of torque calculation. In contrast, the traditional calculation method of T=9550p / n lacks comparative data, making it difficult to determine the accuracy of its data calculation.

[0049] Figure 3A This is a flowchart illustrating an example of a method for determining whether the acquired speed of a pitch motor meets the torque calculation requirements.

[0050] Reference Figure 3A In step S301, it can be determined whether the acquired rotational speed v2 of the pitch motor is less than a first threshold. According to embodiments of this disclosure, the first threshold can be, but is not limited to, 10 degrees / second. In practice, when encoder jumps, communication interruptions, or encoder data acquisition module failures occur, the calculated rotational speed will usually be greater than 12 degrees / second due to the angle value jump. Therefore, the first threshold can be 10 degrees / second.

[0051] In response to the acquisition of a pitch motor speed v2 being less than a first threshold, in step S302, it can be determined whether the ratio of the acquired pitch motor speed v2 to the given speed v3 at the end of the current calculation period T is less than a second threshold. Here, by determining whether the ratio of the acquired pitch motor speed v2 to the given speed v3 is less than the second threshold, the possibility of pitch motor stall can be effectively ruled out. This is because when the acquired pitch motor speed v2 is less than the given speed v3 to a certain extent, pitch motor stall can be determined. Therefore, according to the embodiments of this disclosure, the second threshold can be set according to actual needs, as long as the second threshold can effectively determine the pitch motor stall situation. Optionally, step S302 can be performed before step S301.

[0052] In response to the fact that the ratio of the acquired pitch motor speed v2 to the given speed v3 at the end of the current calculation period T is not less than a second threshold, in step S303, it can be determined that the acquired pitch motor speed v2 meets the torque calculation requirements. Alternatively, when the acquired pitch motor speed v2 is not less than a first threshold or the ratio of the acquired pitch motor speed v2 to the given speed v3 at the end of the current calculation period T is less than a second threshold, it can be determined that the acquired pitch motor speed v2 does not meet the torque calculation requirements, and thus the process returns to step S201 to acquire the pitch motor speed at the end of the next calculation period.

[0053] Figure 3B This is a flowchart illustrating another example of a method for determining whether the acquired speed of the pitch motor meets the torque calculation requirements.

[0054] Before determining whether the obtained pitch motor speed v2 meets the torque calculation requirements, it is necessary to obtain the pitch motor speed v0 at the start of the current calculation period T. As mentioned above, the pitch motor speed v0 at the start of the current calculation period T can be obtained through various methods, and this disclosure does not impose any limitations on this.

[0055] In step S311, the acceleration a of the pitch motor in the current calculation period T can be calculated based on the pitch motor speed v2 at the end of the current calculation period T and the pitch motor speed v0 at the start of the current calculation period T.

[0056] Then, in step S312, it can be determined whether the acceleration a of the pitch motor is zero. Since the torque of the pitch motor is calculated according to formula (5) in the embodiments of this disclosure, by executing step S312, the situation where the pitch motor speed reaches a constant speed, causing formula (5) to be inapplicable, can be effectively eliminated.

[0057] In response to the non-zero acceleration 'a' of the pitch motor, in step S313, it can be determined whether the rotational speed v2 of the pitch motor at the end of the current calculation period T is less than a first threshold. Similarly, step S313 can be performed before steps S311 and / or S312.

[0058] If the speed v2 of the pitch motor is less than the first threshold at the end of the current calculation period T, it can be determined in step S314 that the obtained speed v2 of the pitch motor meets the torque calculation requirements.

[0059] On the other hand, when the acceleration 'a' of the pitch motor is zero, the pitch motor torque determination method according to the embodiments of this disclosure cannot be applied, and therefore the pitch motor torque determination method according to the embodiments of this disclosure can be exited. Furthermore, as described above, when the obtained pitch motor speed v2 is not less than the first threshold, it can be determined that the obtained pitch motor speed v2 does not meet the torque calculation requirements, and thus the process returns to step S201 to obtain the pitch motor speed at the end of the next calculation cycle.

[0060] Return to reference Figure 1 According to embodiments of this disclosure, before executing step S203, data verification can be performed based on the pitch motor speed v2 at the end of the current calculation period T and the pitch motor speed v0 at the start of the current calculation period T. If the data verification is successful, step S203 is executed. Alternatively, if the data verification fails, the pitch motor torque determination method according to embodiments of this disclosure can be exited.

[0061] Specifically, data verification can be performed through the following steps. First, the acceleration *a* of the pitch motor in the current calculation period T can be calculated based on the pitch motor's rotational speed *v2* at the end of the current calculation period T and the pitch motor's rotational speed *v0* at the start of the current calculation period T. Then, it is determined whether the pitch motor's acceleration *a* is less than a third threshold. When the pitch motor's acceleration *a* is less than the third threshold, the data verification is considered successful. According to embodiments of this disclosure, by performing data verification, abnormal acceleration of the pitch motor during the current calculation period (i.e., acceleration time) can be effectively eliminated. Therefore, the third threshold can be set according to actual needs, as long as the third threshold can effectively determine that the pitch motor's acceleration is not abnormal.

[0062] Alternatively, the pitch motor torque determination method according to embodiments of the present disclosure can also effectively determine the stall torque of the pitch motor when it is stalled. The reason for the stall torque is that if the actual speed of the pitch motor is less than the given speed, since the magnitude of the torque is proportional to the magnitude of the acceleration, the change in the actual speed is smaller, indicating that the pitch motor is subjected to a corresponding amount of frictional resistance. When the pitch motor is running, it increases the torque to overcome the frictional resistance of the brake valve in order to keep up with the given speed, thereby generating stall torque.

[0063] As described above, when the ratio of the acquired pitch motor speed v2 to the given speed v3 at the end of the current calculation period T is less than a second threshold, it can be determined that the pitch motor is stalled. In this case, the actual torque of the pitch motor can first be determined based on the pre-calculated actual torque F1 of the pitch motor under standard operating conditions of the laboratory loading platform, the current calculation period T, and the acquired pitch motor speed v2. Then, the stall torque of the pitch motor can be determined based on the actual torque of the pitch motor, the given speed v3 at the end of the current calculation period T, and the acquired pitch motor speed v2. Specifically, the quotient of the given speed v3 at the end of the current calculation period T and the acquired pitch motor speed v2 can be calculated, and the product of the actual pitch motor torque and the quotient is determined as the stall torque of the pitch motor.

[0064] As described above, the actual torque of the pitch motor under standard operating conditions can be calculated based on the equivalent mass m of the pitch motor during rotation, the actual acceleration time t1 of the pitch motor under standard operating conditions of the laboratory loading platform, and the actual speed v1 of the pitch motor. Furthermore, the actual torque of the pitch motor can be determined based on the actual torque F1 of the pitch motor under standard operating conditions of the laboratory loading platform, the actual acceleration time t1 of the pitch motor, the actual speed v1 of the pitch motor, the current calculation period T, and the obtained speed v2 of the pitch motor.

[0065] Since the pitch motor torque determination method according to the embodiments of this disclosure can effectively calculate the stall torque of the pitch motor, it can provide sufficient basis for the selection of the pitch motor.

[0066] Figure 4 This is a block diagram illustrating a torque determination device for a pitch motor according to an embodiment of the present disclosure.

[0067] The torque determination device for the pitch motor according to embodiments of the present disclosure can be installed in each pitch controller of the wind turbine generator set. However, the present disclosure is not limited thereto; the torque determination device for the pitch motor according to embodiments of the present disclosure can be installed in the main controller or other controllers of the wind turbine generator set.

[0068] Reference Figure 4The pitch motor torque determination device 400 may include a speed acquisition module 410, a calculation requirement determination module 420, and a torque determination module 430. The speed acquisition module 410 acquires the pitch motor speed v2 at the end of the current calculation period T. The calculation requirement determination module 420 determines whether the acquired pitch motor speed v2 meets the torque calculation requirements. In response to the acquired pitch motor speed meeting the torque calculation requirements, the torque determination module 430 determines the actual torque of the pitch motor based on the pre-calculated actual torque F1 of the pitch motor under standard operating conditions of the laboratory loading platform, the current calculation period T, and the acquired pitch motor speed v2. Here, the actual torque of the pitch motor under standard operating conditions of the laboratory loading platform can be calculated based on the equivalent mass m of the pitch motor during rotation, the actual acceleration time t1 of the pitch motor under standard operating conditions of the laboratory loading platform, and the actual speed v1 of the pitch motor. The torque determination module 430 can determine the actual torque of the pitch motor based on the actual torque F1 of the pitch motor under standard operating conditions of the laboratory loading platform, the actual acceleration time t1 of the pitch motor, the actual speed v1 of the pitch motor, the current calculation period T, and the obtained speed v2 of the pitch motor.

[0069] The calculation requirement determination module 420 can determine whether the acquired pitch motor speed v2 is less than a first threshold, and whether the ratio of the acquired pitch motor speed v2 to the given speed v3 at the end of the current calculation period T is less than a second threshold. In response to the condition that the acquired pitch motor speed v2 is less than the first threshold and the ratio of the acquired pitch motor speed v2 to the given speed v3 at the end of the current calculation period T is not less than the second threshold, the calculation requirement determination module 420 can determine that the acquired pitch motor speed v2 meets the torque calculation requirements.

[0070] Optionally, the speed acquisition module 410 can also acquire the speed v0 of the pitch motor at the start of the current calculation period T, where the speed v0 of the pitch motor at the start can be 0. The calculation requirement determination module 420 can calculate the acceleration a of the pitch motor in the current calculation period T based on the speed v2 of the pitch motor at the end of the current calculation period T and the speed v0 of the pitch motor at the start of the current calculation period T, determine whether the acceleration a of the pitch motor is zero, and determine whether the speed v2 of the pitch motor at the end of the current calculation period T is less than a first threshold. In response to the pitch motor acceleration a being non-zero and the speed v2 of the pitch motor at the end of the current calculation period T being less than the first threshold, the calculation requirement determination module 420 can determine that the acquired speed v2 of the pitch motor meets the torque calculation requirements.

[0071] According to embodiments of this disclosure, the pitch motor torque determination device 400 may further include a data verification module (not shown). The data verification module performs data verification based on the pitch motor speed v2 at the end of the current calculation period T and the pitch motor speed v0 at the start of the current calculation period T. In response to successful data verification, the torque determination module 430 determines the actual torque of the pitch motor. Specifically, the data verification module calculates the pitch motor acceleration a in the current calculation period T based on the pitch motor speed v2 at the end of the current calculation period T and the pitch motor speed v0 at the start of the current calculation period T, and determines whether the pitch motor acceleration a is less than a third threshold. In response to the pitch motor acceleration being less than the third threshold, the data verification module determines that the data verification was successful.

[0072] According to embodiments of this disclosure, in response to the ratio of the acquired pitch motor speed v2 to the given speed v3 at the end of the current calculation period T being less than a second threshold, the torque determination module 430 can determine the actual torque of the pitch motor based on the pre-calculated actual torque F1 of the pitch motor under standard operating conditions of the laboratory loading platform, the current calculation period T, and the acquired pitch motor speed v2. Furthermore, it can determine the stall torque of the pitch motor based on the actual torque of the pitch motor, the given speed v3 at the end of the current calculation period T, and the acquired pitch motor speed v2. Specifically, the torque determination module 430 can calculate the actual torque of the pitch motor under standard operating conditions of the laboratory loading platform based on the equivalent mass m of the pitch motor during rotation, the actual acceleration time t1 of the pitch motor under standard operating conditions of the laboratory loading platform, and the actual speed v1 of the pitch motor. It can also determine the actual torque of the pitch motor based on the actual torque F1 of the pitch motor under standard operating conditions of the laboratory loading platform, the actual acceleration time t1 of the pitch motor, the actual speed v1 of the pitch motor, the current calculation period T, and the acquired pitch motor speed v2. For example, the torque determination module 430 can calculate the quotient of the acquired pitch motor speed v2 and the current calculation period T as a first value, calculate the quotient of the actual pitch motor speed v1 and the actual acceleration time t1 under standard operating conditions of the laboratory loading platform as a second value, calculate the quotient of the first value and the second value as a third value, and determine the actual torque of the pitch motor by multiplying the actual torque of the pitch motor under standard operating conditions by the third value. Furthermore, the torque determination module 430 can calculate the quotient of the given speed v3 at the end of the current calculation period T and the acquired pitch motor speed v2, and determine the stall torque of the pitch motor by multiplying the actual torque of the pitch motor by the quotient.

[0073] Figure 5 This is a block diagram illustrating a controller for a wind turbine generator set according to an embodiment of the present disclosure.

[0074] Reference Figure 5 The controller 500 of the wind turbine generator set according to embodiments of the present disclosure may be, but is not limited to, a pitch controller, a main controller of the wind turbine generator set, etc. The controller 500 of the wind turbine generator set according to embodiments of the present disclosure may include a processor 510 and a memory 520. The processor 510 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 520 stores computer programs to be executed by the processor 510. The memory 520 includes high-speed random access memory and / or non-volatile computer-readable storage media. When the processor 510 executes the computer program stored in the memory 520, the torque determination method of the pitch motor as described above can be implemented.

[0075] Optionally, the controller 500 can communicate with other components in the wind turbine generator set via wired / wireless communication, and also with other devices in the wind farm via wired / wireless communication. Furthermore, the controller 500 can communicate with devices outside the wind farm via wired / wireless communication. Additionally, the controller 500 may have timer and encoder functions.

[0076] The pitch motor torque determination method according to embodiments of the present 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 motor torque determination method 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-RLTH, B D-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.

[0077] The pitch motor torque determination method according to embodiments of this disclosure does not require the use of the pitch motor's voltage or current, nor does it involve factors such as power factor or motor mechanical efficiency. Therefore, it can improve the accuracy of torque calculation and achieve universality in pitch motor torque calculation. Furthermore, the pitch motor torque determination method according to embodiments of this disclosure is applicable to the statistical calculation of torque values ​​for any type of pitch motor and can guarantee the calculation accuracy of low-speed data, solving the problem of inaccurate pitch motor torque calculation at low speeds. In addition, the pitch motor torque determination method according to embodiments of this disclosure is independent of the forward and backward positions of the blade angle, only related to the angle change process and duration, thereby reducing its computational complexity. Moreover, the pitch motor torque determination method according to embodiments of this disclosure uses the actual torque of a laboratory loading platform under standard operating conditions, thus ensuring the accuracy of torque calculation. In contrast, the traditional calculation method of T=9550p / n lacks comparative data, making it difficult to determine the accuracy of the calculated data. Meanwhile, the pitch motor torque determination method according to the embodiments of this disclosure can effectively calculate the stall torque of the pitch motor, thereby providing sufficient basis for the selection of the pitch motor.

[0078] 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 method for determining the torque of a pitch motor, characterized in that, The torque determination method includes: Obtain the rotational speed of the pitch motor at the end of the current calculation cycle, wherein the rotational speed of the pitch motor at the start of the current calculation cycle is 0. Determine whether the obtained speed of the pitch motor meets the torque calculation requirements; In response to the fact that the acquired pitch motor speed meets the torque calculation requirements, the actual torque of the pitch motor is determined based on the current calculation cycle, the acquired pitch motor speed, and the pre-calculated actual torque, actual acceleration time, and actual speed of the pitch motor under standard operating conditions on the laboratory loading platform. The steps for determining the actual torque of the pitch motor include: The first value is the quotient of the calculated pitch motor speed and the current calculation cycle. The second value is the quotient of the actual speed of the pitch motor and the actual acceleration time of the laboratory loading platform under standard operating conditions. Calculate the quotient of the first value and the second value as the third value; The actual torque of the pitch motor is determined by multiplying the actual torque of the pitch motor under standard operating conditions on the laboratory loading platform with the third value.

2. The torque determination method as described in claim 1, characterized in that, The actual torque of the pitch motor under standard operating conditions is calculated based on the equivalent mass of the pitch motor during rotation, the pitch motor's torsional radius, the actual acceleration time of the pitch motor under standard operating conditions of the laboratory loading platform, and the actual speed of the pitch motor.

3. The torque determination method as described in claim 1, characterized in that, The steps to determine whether the obtained speed of the pitch motor meets the torque calculation requirements include: Determine whether the obtained speed of the pitch motor is less than the first threshold. Determine whether the ratio of the obtained pitch motor speed to the given speed at the end of the current calculation cycle is less than a second threshold. In response to the fact that the obtained pitch motor speed is less than a first threshold and the ratio of the obtained pitch motor speed to the given speed at the end of the current calculation cycle is not less than a second threshold, it is determined that the obtained pitch motor speed meets the torque calculation requirements.

4. The torque determination method as described in claim 1, characterized in that, The steps to determine whether the obtained speed of the pitch motor meets the torque calculation requirements include: Calculate the acceleration of the pitch motor in the current calculation cycle based on the speed of the pitch motor at the end of the current calculation cycle and the speed of the pitch motor at the beginning of the current calculation cycle. Determine if the acceleration of the pitch motor is zero; Determine whether the speed of the pitch motor at the end of the current calculation cycle is less than the first threshold. In response to the fact that the acceleration of the pitch motor is not zero and the speed of the pitch motor at the end of the current calculation cycle is less than the first threshold, it is determined that the obtained speed of the pitch motor meets the torque calculation requirements.

5. The torque determination method as described in claim 1, characterized in that, The torque determination method further includes: Based on the pitch motor speed at the end of the current calculation cycle and the pitch motor speed at the start of the current calculation cycle, perform data verification. In response to successful data verification, the step of determining the torque of the pitch motor is executed.

6. The torque determination method as described in claim 5, characterized in that, The steps for performing data validation include: Calculate the acceleration of the pitch motor in the current calculation cycle based on the speed of the pitch motor at the end of the current calculation cycle and the speed of the pitch motor at the beginning of the current calculation cycle. Determine whether the acceleration of the pitch motor is less than the third threshold. Among them, the data verification is determined to be successful when the acceleration of the pitch motor is less than the third threshold.

7. The torque determination method as described in claim 3, characterized in that, The torque determination method further includes: In response to the ratio of the acquired pitch motor speed to the given speed at the end of the current calculation cycle being less than a second threshold, the actual torque of the pitch motor is determined based on the current calculation cycle, the acquired pitch motor speed, and the pre-calculated actual torque, actual acceleration time, and actual speed of the pitch motor of the laboratory loading platform under standard operating conditions. The stall torque of the pitch motor is determined based on the actual torque of the pitch motor, the given speed at the end of the current calculation cycle, and the obtained speed of the pitch motor.

8. The torque determination method as described in claim 7, characterized in that, The steps to determine the stall torque of a pitch motor include: Calculate the ratio of the given rotational speed at the end of the current calculation cycle to the obtained rotational speed of the pitch motor; The product of the actual torque of the pitch motor and the quotient is determined as the stall torque of the pitch motor.

9. A torque determination device for a pitch motor, characterized in that, The torque determination device includes: The rotational speed acquisition module is configured to acquire the rotational speed of the pitch motor at the end of the current calculation cycle, wherein the rotational speed of the pitch motor at the start of the current calculation cycle is 0. The calculation requirement determination module is configured to determine whether the acquired pitch motor speed meets the torque calculation requirements; The torque determination module is configured to determine the actual torque of the pitch motor in response to the acquired pitch motor speed meeting the torque calculation requirements, based on the current calculation cycle, the acquired pitch motor speed, and pre-calculated actual torque, actual acceleration time, and actual speed of the pitch motor under standard operating conditions on the laboratory loading platform. The torque determination module is configured as follows: The first value is the quotient of the calculated pitch motor speed and the current calculation cycle. The second value is the quotient of the actual speed of the pitch motor and the actual acceleration time of the laboratory loading platform under standard operating conditions. Calculate the quotient of the first value and the second value as the third value; The actual torque of the pitch motor is determined by multiplying the actual torque of the pitch motor under standard operating conditions on the laboratory loading platform with the third value.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the torque determination method for the pitch motor as described in any one of claims 1 to 8.

11. A controller, characterized in that, The controller includes: processor; and A memory storing a computer program that, when executed by a processor, implements the torque determination method for a pitch motor as described in any one of claims 1 to 8.

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