Control method, control system and readable storage medium of wind turbine generator

Abstract

The application provides a wind turbine control method, a control system and a readable storage medium. The wind turbine control method comprises: performing virtual inertia control on the wind turbine according to a first target power of the wind turbine, so that the wind turbine outputs the first target power. After performing the virtual inertia control for a first set time length, a first additional torque is determined according to a second target power of the wind turbine and a current electromagnetic torque of the wind turbine after the virtual inertia control. The output power of the wind turbine is controlled to be between the first target power and the second target power or equal to the second target power according to the first additional torque. One of the first target power and the second target power is greater than the current power of the wind turbine, and the other is less than the current power of the wind turbine. In this way, the wind turbine can avoid causing negative effects on the power grid again after the inertia support ends.

Description

Technical Field

[0001] This application relates to the field of wind power technology, and in particular to a control method, control system and readable storage medium for a wind turbine generator. Background Technology

[0002] With the gradual depletion of energy sources such as coal and oil, humanity is increasingly emphasizing the utilization of renewable energy. Wind energy, as a clean and renewable energy source, is receiving growing attention worldwide. For coastal islands, grassland pastoral areas, mountainous regions, and plateaus lacking water, fuel, and with inconvenient transportation, the appropriate use of wind power is highly suitable and has great potential. Wind power generation refers to the conversion of the kinetic energy of wind into electrical energy using wind turbines.

[0003] As wind power accounts for an increasing proportion of the power grid, its impact on grid stability is becoming more and more apparent, and wind turbines are increasingly considered to have frequency regulation capabilities similar to those of traditional thermal power generators.

[0004] Inertia support is one of the important ways for wind turbines to participate in the primary frequency regulation of the power grid. However, after the support is completed, the frequency of the wind turbines may drop or rise, which will affect the grid frequency again and have a negative impact on the grid. Summary of the Invention

[0005] The purpose of this application is to provide a control method, control system, and computer-readable storage medium for wind turbines that do not cause further negative impacts on the power grid after the support is completed.

[0006] This application provides a control method for a wind turbine generator, including:

[0007] Based on the first target power of the wind turbine, virtual inertia control is performed on the wind turbine to make the wind turbine output the first target power;

[0008] After performing the virtual inertia control for the first set duration, the first additional torque is determined based on the second target power of the wind turbine and the current electromagnetic torque of the wind turbine after performing virtual inertia control.

[0009] Based on the first additional torque, the output power of the wind turbine is controlled to be between or equal to the second target power and the first target power;

[0010] Wherein, one of the first target power and the second target power is greater than the current power of the wind turbine, and the other is less than the current power of the wind turbine.

[0011] Optionally, after performing the virtual inertia control for a first set duration, determining the first additional torque based on the second target power of the wind turbine and the current electromagnetic torque of the wind turbine after performing virtual inertia control includes:

[0012] Based on the second target power, determine the second target torque of the wind turbine after virtual inertia control; and

[0013] The first additional torque is determined based on the current electromagnetic torque and the second target torque;

[0014] Specifically, when the change in grid frequency is positive, the second target power is greater than the current power of the wind turbine, and the current electromagnetic torque is not greater than the second target torque;

[0015] When the change in grid frequency is negative, the second target power is less than the current power of the wind turbine, and the current electromagnetic torque is not less than the second target torque.

[0016] Optionally, the step of performing virtual inertia control on the wind turbine based on the first target power of the wind turbine, so that the wind turbine outputs the first target power, includes:

[0017] Obtain the rate of change and the amount of change of the current power grid frequency relative to the target power grid frequency;

[0018] If the rate of change and the amount of change satisfy the triggering conditions for virtual inertia control of the wind turbine, the wind turbine is controlled to perform virtual inertia control.

[0019] Optionally, the triggering conditions for the wind turbine to enter virtual inertia control include:

[0020] The current grid frequency change rate continues for a second set time, the current grid frequency change amount reaches a set value, the interval since the last virtual inertia control reaches a third set time, and the wind turbine is in normal power generation state.

[0021] Optional, also includes:

[0022] If the rate of change and the amount of change satisfy the triggering conditions for the wind turbine to perform virtual inertia control, before performing virtual inertia control, a second additional torque is determined based on the rate of change and the amount of change, and the wind turbine is controlled to output a third target power based on the second additional torque.

[0023] The third target power is greater than the first target power.

[0024] Optionally, the step of performing virtual inertia control on the wind turbine based on the first target power of the wind turbine, so that the wind turbine outputs the first target power, includes:

[0025] When the wind turbine is subjected to virtual inertia control, the first current rotational speed of the wind turbine rotor is obtained;

[0026] If the first current rotational speed is less than the set rotational speed of the wind turbine rotor, the wind turbine is controlled to exit virtual inertia control.

[0027] Optionally, after performing the virtual inertia control for a first set duration, determining the first additional torque based on the second target power of the wind turbine and the current electromagnetic torque of the wind turbine after performing virtual inertia control includes:

[0028] After performing virtual inertia control for a first set time, the second current rotational speed of the wind turbine rotor is obtained;

[0029] If the second current speed is less than the set speed of the wind turbine rotor, the first additional torque is controlled to be 0.

[0030] Optional, also includes:

[0031] Before performing virtual inertia control on the wind turbine, the third current rotational speed of the wind turbine rotor is obtained;

[0032] When the wind turbine is subjected to virtual inertia control, the first current rotational speed of the wind turbine rotor is obtained;

[0033] The step of performing virtual inertia control on the wind turbine based on the first target power of the wind turbine, so that the wind turbine outputs the first target power, includes:

[0034] The compensation torque is determined based on the first current speed and the third current speed;

[0035] The third additional torque is determined based on the first target power of the wind turbine and the compensation torque.

[0036] Based on the third additional torque, control the wind turbine to output the first target power.

[0037] This application provides a control system for a wind turbine generator, including one or more processors for implementing the control method described in any of the above claims.

[0038] This application provides a computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the control method described in any of the above claims.

[0039] The wind turbine control method of this application embodiment controls the wind turbine to output a first target power by performing virtual inertia control on the wind turbine, thereby providing inertia support to the power grid. After a first set duration of virtual inertia control, the output power of the wind turbine is controlled to be between or equal to the second target power. By limiting the output power of the wind turbine with a first additional torque, it is possible to prevent the wind turbine from affecting the power grid frequency again after the inertia support ends, thus avoiding negative impacts on the power grid. Attached Figure Description

[0040] Figure 1 The figure shown is a three-dimensional structural schematic diagram of a wind turbine generator set according to one embodiment of this application;

[0041] Figure 2 The diagram shown is a flowchart illustrating a control method for a wind turbine generator according to one embodiment of this application.

[0042] Figure 3 As shown Figure 2 The diagram shows a flow chart illustrating the control method for wind turbine generators, specifically the virtual inertia control process.

[0043] Figure 4 As shown Figure 2 The flowchart shown illustrates the determination of the compensation torque in the control method of the wind turbine generator set.

[0044] Figure 5 As shown Figure 2 The diagram shows the process of controlling the wind turbine to exit virtual inertia control.

[0045] Figure 6 As shown Figure 2 The flowchart shown illustrates the determination of the first additional torque in the control method of the wind turbine generator.

[0046] Figure 7 As shown Figure 2 The flowchart shown illustrates the control method for a wind turbine generator set, where the first additional torque is 0.

[0047] Figure 8 The diagram shown is a block diagram of the control system of a wind turbine generator according to an embodiment of this application. Detailed Implementation

[0048] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses consistent with some aspects of this application as detailed in the appended claims.

[0049] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit the application. Unless otherwise defined, the technical or scientific terms used in this application should be understood in their ordinary sense by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar words used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, "an" or "a" and similar words do not indicate a quantity limitation, but rather indicate the presence of at least one. "A plurality" or "several" indicates two or more. The terms "comprising" or "including," and similar words mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. The terms "connected" or "linked," and similar words are not limited to physical or mechanical connections and can include electrical connections, whether direct or indirect. The singular forms "a," "the," and "the" used in this application specification and appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0050] The wind turbine control method of this application embodiment includes: performing virtual inertia control on the wind turbine according to a first target power, so that the wind turbine outputs the first target power. After a first set duration of virtual inertia control, determining a first additional torque based on a second target power and the current electromagnetic torque of the wind turbine after virtual inertia control. Based on the first additional torque, controlling the output power of the wind turbine to be between or equal to the second target power and the first target power. Wherein, one of the first target power and the second target power is greater than the current power of the wind turbine, and the other is less than the current power of the wind turbine.

[0051] The wind turbine control method of this application embodiment controls the wind turbine to output a first target power by performing virtual inertia control on the wind turbine, thereby providing inertia support to the power grid. After a first set time of virtual inertia control, the output power of the wind turbine is controlled to be between or equal to the second target power. By limiting the output power of the wind turbine with a first additional torque, it is possible to prevent the wind turbine from affecting the power grid frequency again after the inertia support ends.

[0052] Wind power generation converts the kinetic energy of wind into mechanical kinetic energy, and then into electrical kinetic energy. The device used for wind power generation is called a wind turbine generator set or wind turbine unit. This application provides a control method, control system, and computer-readable storage medium for a wind turbine generator set. The following detailed description, in conjunction with the accompanying drawings, further illustrates this application.

[0053] Figure 1 This application describes a wind turbine generator set 10 according to one embodiment, comprising: a tower 20, a nacelle 21, and a rotor 22. The nacelle 21 is mounted on top of the tower 20, and the tower 20 supports the nacelle 21. The rotor 22 is mounted on the nacelle 21 and includes a hub 25 and blades 26 mounted on the hub 25. In this embodiment, the rotor 22 is mounted at the front of the nacelle 21; in other embodiments, the rotor 22 may be mounted at the rear of the nacelle 21. The number of blades 26 is three; in other examples, the number of blades 26 can be set according to actual conditions.

[0054] The wind turbine 22 is a component that converts the kinetic energy of the wind into mechanical energy. When the wind blows towards the blades 26, the aerodynamic force generated on the blades 26 drives the wind turbine 22 to rotate. A generator connected to the wind turbine 22 can be installed inside the nacelle 21. The rotation of the wind turbine 22 drives the rotor inside the generator to rotate, thereby generating electricity.

[0055] As wind power accounts for an increasing proportion of the power grid, wind turbine generators (10) are also considered to have primary frequency regulation capabilities. Primary frequency regulation refers to the control process by which the control system of wind turbine generators (10) controls the increase or decrease of the active power output of wind turbine generators (10) to limit grid frequency changes and maintain grid frequency stability when the grid frequency deviates from its rated value. When the grid frequency increases, the primary frequency regulation function requires wind turbine generators (10) to reduce their grid-connected active power; conversely, wind turbine generators (10) increase their grid-connected active power when the grid frequency decreases.

[0056] Inertia support is a method for wind turbines to participate in primary frequency regulation. Inertia support involves rapidly transferring rotor kinetic energy based on system conditions, providing short-term support for the grid frequency. To enable the wind turbine 10 to exhibit the inertia characteristics of a synchronous generator, additional control components need to be added to the converter, thereby altering the active power output of the wind turbine 10. However, after the support process ends, the wind turbine 10 may experience a frequency drop or rise, again affecting the grid frequency and causing further negative impacts on the grid.

[0057] See Figure 2 As shown, this application embodiment provides a control method for a wind turbine generator set 10. The control method for the wind turbine generator set 10 includes steps S101 to S103.

[0058] In step S101, virtual inertia control is performed on the wind turbine 10 according to the first target power, so that the wind turbine 10 outputs the first target power.

[0059] In some embodiments, the first target power can be a power given by the power grid, such as the power that the power grid requires the wind turbine 10 to output when supported by inertia. The first target power can also be the power output when supported by inertia, set according to the power supply capacity of the wind turbine 10. For example, based on the current power of the wind turbine 10, when the grid frequency increases, the first target power can be the current power minus 0.1 times the rated power; when the grid frequency decreases, the first target power can be the current power plus 0.1 times the rated power. Of course, the current power of the wind turbine 10 can be the rated power of the wind turbine 10.

[0060] It should be noted that virtual inertia control is a method for providing inertia support for the wind turbine 10. Virtual inertia control involves changing the control method of the grid-side converter to simulate a generator, thereby providing virtual rotational inertia. Because the grid-side converter is simulated as a generator, the output power of the wind turbine 10 is equal to the output power of the generator. The generator's speed can be the speed of the wind turbine rotor of the wind turbine 10. According to the formula Power = Torque * Speed, when the output power of the wind turbine 10 and the speed of the wind turbine rotor are determined, the control torque of the generator can be determined.

[0061] Please refer to Figure 3 In some embodiments, step S101 includes steps S1001 and S1002.

[0062] In step S1001, the rate of change and the amount of change of the current grid frequency relative to the target grid frequency are obtained. In some embodiments, the target grid frequency can be a rated value of the grid frequency, such as 50Hz. The current grid frequency can be obtained from the grid-side converter of the wind turbine 10, from which the real-time changing grid frequency can be obtained. For example, if the grid frequency changes from 50Hz to 48Hz within 4 seconds, then the amount of change of the current grid frequency 48Hz relative to the target grid frequency 50Hz is 2Hz, and the rate of change is 0.5Hz / s.

[0063] In step S1002, if the rate of change and the amount of change meet the triggering conditions for the wind turbine 10 to perform virtual inertia control, the wind turbine 10 is controlled to perform virtual inertia control.

[0064] In some embodiments, the triggering conditions for the wind turbine 10 to enter virtual inertia control include: the rate of change of the current grid frequency lasting for a second set duration, the change in the current grid frequency reaching a set value, the interval since the last virtual inertia control reaching a third set duration, and the wind turbine 10 being in normal power generation mode. Simultaneously meeting the triggering conditions for entering virtual inertia control can prevent the wind turbine 10 from erroneously triggering virtual inertia control, ensuring the operational safety of the wind turbine 10 and guaranteeing the wind turbine 10's support effect on the grid frequency.

[0065] The second set duration can be a user-defined duration, such as 0.04s, which can be flexibly selected. The current grid frequency change rate remains within the second set duration to eliminate the influence of noise and prevent the wind turbine 10 from erroneously triggering virtual inertia control. When the change in the current grid frequency reaches a set value, such as 0.15Hz, virtual inertia control can be triggered when the change exceeds the dead zone, preventing erroneous triggering. The dead zone can be 0.15Hz, 0.18Hz, etc., and this application does not impose any restrictions on this. A dead zone can also be set for the current grid frequency change rate, such as 0.1Hz / s. The interval since the last virtual inertia control reaches a third set duration. The third set duration can be set according to the performance of the wind turbine 10, such as 5 minutes, to ensure the safe operation of the wind turbine 10. When the wind turbine 10 is in normal power generation mode, the operating status of the wind turbine 10 can be obtained from the main control system of the wind turbine 10. When the wind turbine 10 is in normal power generation mode, the support effect of the wind turbine 10 on the grid frequency can be guaranteed.

[0066] Before virtual inertia control is implemented in wind turbine 10, the third current rotational speed of the wind turbine rotor is obtained. This third current rotational speed is the rotor speed at the moment the wind turbine 10 enters virtual inertia control. Based on the first target power and the third current rotational speed, the first target torque can be obtained using the formula: Power = Torque * Rotational Speed. Before virtual inertia control, the output power of wind turbine 10 can be the current power. Based on the current power and the third current rotational speed, the generator's control torque can be obtained. By comparing the first target torque and the control torque, a third additional torque is applied to the grid-side converter, making the first target torque equal to the control torque plus the third additional torque. This allows wind turbine 10 to output the first target power, satisfying the inertia support of wind turbine 10 against grid frequency fluctuations.

[0067] In some embodiments, the frequency variation of the power grid includes positive and negative variations. A positive variation indicates that the power grid frequency increases relative to its rated value, in which case the power grid frequency should be decreased to its rated value, and the wind turbine needs to reduce its active power output when performing virtual inertia control. A negative variation indicates that the power grid frequency decreases relative to its rated value, in which case the power grid frequency should be increased to its rated value, and therefore the wind turbine needs to increase its active power output when performing virtual inertia control. In some optional embodiments, the rated power grid frequency is 50 Hz.

[0068] When the grid frequency changes positively, the first target power is less than the current power of the wind turbine, causing the wind turbine to reduce its active power output. Therefore, the third additional torque is negative, making the first target torque less than the control torque to satisfy the inertia support of the wind turbine when the grid frequency changes positively. When the grid frequency changes negatively, the first target power is greater than the current power of the wind turbine, causing the wind turbine to increase its active power output. Therefore, the third additional torque is positive, making the first target torque greater than the control torque to satisfy the inertia support of the wind turbine when the grid frequency changes negatively.

[0069] Please refer to Figure 4 In some embodiments, step S101 further includes steps S104 to S106.

[0070] Before performing virtual inertia control on the wind turbine 10, the third current rotational speed of the wind turbine 10 is obtained. The third current rotational speed has been described above and will not be repeated here.

[0071] When the wind turbine 10 performs virtual inertia control, the first current rotational speed of the wind turbine 10 is obtained. The first current rotational speed is the rotational speed of the wind turbine 10's rotor during the virtual inertia control process, and it can be obtained through the rotor's rotational speed sensor.

[0072] When the frequency of the power grid changes negatively, the rotor kinetic energy is released during the virtual inertia control process of the wind turbine 10, so that the first current speed of the wind turbine 10 is less than the third current speed, and the output power of the wind turbine is less than the first target power.

[0073] In step S104, the compensation torque is determined based on the first current speed and the third current speed. The compensation torque can be obtained using the formula: Compensation Torque = (Third Current Speed ​​* Control Torque) / First Current Speed ​​- Control Torque.

[0074] In step S105, a third additional torque is determined based on the first target power and compensation torque of the wind turbine 10. The third additional torque can be obtained by the formula: third additional torque = (compensation torque + first target torque - control torque), where the first target torque can be obtained by the formula: first target torque = first target power / third current speed.

[0075] In step S106, the wind turbine 10 is controlled to output the first target power according to the third additional torque. Applying the third additional torque to the grid-side converter to make the wind turbine 10 output the first target power can compensate for the reduction in the output power of the wind turbine 10 caused by the decrease in the wind turbine speed, thereby ensuring the support effect of the wind turbine 10 on the power grid.

[0076] Please refer to Figure 5 In some embodiments, step S101 further includes steps S107 to S108.

[0077] In step S107, when the wind turbine 10 performs virtual inertia control, the first current rotational speed of the wind turbine 10 is obtained. The first current rotational speed is the rotational speed of the wind turbine 10's rotor during the virtual inertia control process, and it can be obtained through the rotor's rotational speed sensor.

[0078] In step S108, if the first current rotational speed is less than the set rotational speed of the wind turbine rotor of the wind turbine 10, the wind turbine 10 is controlled to exit virtual inertia control. During the virtual inertia control of the wind turbine 10 with respect to the power grid, the rotor rotational speed may decrease. Therefore, when the first current rotational speed is less than the set rotational speed of the rotor, the wind turbine 10 can be exited virtual inertia control by setting the third additional torque to 0. This prevents the wind turbine from shutting down due to excessively low rotor rotational speed, ensuring the normal operation of the wind turbine 10. The set rotational speed of the rotor can be specifically set according to the rotor's properties.

[0079] In some embodiments, if the rate of change and the amount of change meet the triggering conditions for virtual inertia control of the wind turbine 10, a second additional torque is determined based on the rate of change and the amount of change before virtual inertia control is performed. Based on the second additional torque, the wind turbine 10 is controlled to output a third target power, wherein the third target power is greater than the first target power. In some embodiments, the second additional torque can be obtained using the formula: Second Additional Torque = (Rate of Change * Rate of Change Gain) + (Amount of Change * Amount of Change Gain). As mentioned above, adding a second additional torque to the generator's control torque can enable the wind turbine 10 to output a third target power. The rate of change gain and the amount of change gain should be set to sufficiently large values ​​so that the third target power output by the wind turbine 10 is greater than the first target power, allowing for faster release of the generator rotor kinetic energy when the grid frequency decreases. When the wind turbine 10 enters virtual inertia control, the second additional torque can also be adjusted to the third additional torque, thus enabling a rapid response and shortening the response time of the wind turbine 10. In some embodiments, the rate of change gain may be 0.2-0.4 times the rated torque, and the amount of change gain may be 0.1-0.2 times the rated torque; this application does not limit this.

[0080] Please continue to refer to this. Figure 2 In step S102, after performing the first set duration of virtual inertia control, the first additional torque is determined based on the second target power of the wind turbine 10 and the current electromagnetic torque of the wind turbine 10 after virtual inertia control. One of the first target power and the second target power is greater than the current power of the wind turbine 10, and the other is less than the current power of the wind turbine 10. After the virtual inertia control reaches the first set duration, the wind turbine 10 ends its inertia support to the grid frequency, preventing the wind turbine 10 from shutting down due to excessive support. The first set duration can be specifically set according to the support capacity of the wind turbine 10, such as 5s, 10s, etc.

[0081] Please refer to Figure 6 In some embodiments, step S102 includes steps S201 and S202.

[0082] In step S201, a second target torque is determined based on the second target power after virtual inertia control of the wind turbine. One of the first target power and the second target power is greater than the current power of the wind turbine, and the other is less than the current power of the wind turbine.

[0083] In some embodiments, when the grid frequency changes positively, the first target power is less than the current power of the wind turbine. During virtual inertia control, the rotor speed increases, and kinetic energy increases. When the wind turbine 10 stops supporting the grid frequency, the energy stored in the wind turbine 10 is released, and the output power of the wind turbine 10 rebounds, exceeding its current power. To prevent the output power of the wind turbine 10 from becoming too high after the inertia support ends, thus affecting the grid frequency again, the output power of the wind turbine 10 needs to be limited to not exceed the second target power. The second target power is greater than the current power of the wind turbine. The second target power can be flexibly set according to the performance of the wind turbine; for example, the second target power can be equal to the current power plus 0.05 times the rated power. After the wind turbine 10 stops supporting the grid frequency, the second target torque can be determined based on the real-time rotor speed and the second target power using the formula Power = Torque * Rotational Speed.

[0084] In some embodiments, when the change in grid frequency is negative, the first target power is greater than the current power of the wind turbine. During virtual inertia control, the wind turbine releases rotor kinetic energy. When the wind turbine 10 stops supporting the grid frequency, its output power decreases due to excessive release of rotor kinetic energy, and its output power becomes less than its current power. To prevent the output power of the wind turbine 10 from dropping too much after the inertia support ends, thus affecting the grid frequency again, the output power of the wind turbine 10 needs to be limited to be no less than the second target power. The second target power is less than the current power of the wind turbine 10. The second target power can be flexibly set according to the performance of the wind turbine; for example, the second target power can be equal to the current power minus 0.05 times the rated power. After the wind turbine 10 stops supporting the grid frequency, the second target torque can be determined based on the real-time rotational speed of the wind turbine and the second target power using the formula Power = Torque * Rotational Speed.

[0085] In step S202, a first additional torque is determined based on the current electromagnetic torque and the second target torque. The current electromagnetic torque is the control torque of the grid-side converter. Specifically, the current electromagnetic torque is the rotational torque generated on the rotor after the grid-side converter is simulated as a generator.

[0086] In some embodiments, when the grid frequency change is positive, the second target power is greater than the current power of the wind turbine, and the current electromagnetic torque is not greater than the second target torque. By comparing the current electromagnetic torque and the second target torque in real time, if the current electromagnetic torque is less than the second target torque, the second additional torque is 0; if the current electromagnetic torque is greater than the second target torque, the first additional torque can be determined by the formula: First Additional Torque = Current Electromagnetic Torque - Second Target Torque. Thus, when the grid frequency change is positive, after exiting virtual inertia control, the wind turbine can control its output power to be less than or equal to the second target power, preventing the grid frequency rebound from affecting the grid frequency again.

[0087] In some embodiments, when the grid frequency change is negative, the second target power is less than the current power of the wind turbine, and the current electromagnetic torque is not less than the second target torque. By comparing the current electromagnetic torque and the second target torque in real time, if the current electromagnetic torque is greater than the second target torque, the first additional torque is 0; if the current electromagnetic torque is less than the second target torque, the first additional torque can be determined by the formula: First Additional Torque = Second Target Torque - Current Electromagnetic Torque. Thus, when the grid frequency change is negative, after exiting virtual inertia control, the wind turbine can control its output power to be greater than or equal to the second target power, preventing the grid frequency rebound from affecting the grid frequency again.

[0088] Please refer to Figure 7 In some embodiments, step S102 further includes steps S203 and S204.

[0089] In step S203, after performing the first set duration of virtual inertia control, the second current rotational speed of the wind turbine rotor is obtained. The second current rotational speed is the real-time rotational speed of the wind turbine rotor after the wind turbine 10 exits virtual inertia control.

[0090] In step S204, when the second current speed is less than the set speed of the wind turbine rotor, the first additional torque is controlled to be 0. When the second current speed is less than the set speed of the wind turbine rotor, the first additional torque is 0, which can prevent the wind turbine rotor from shutting down due to excessively low speed and ensure the normal operation of the wind turbine rotor 10.

[0091] In some embodiments, after the wind turbine 10 exits virtual inertia control, the output power of the wind turbine 10 is maintained between a first target power and a second target power. The duration for which the output power is maintained between the first target power and the second target power can be set to 40s or 60s, etc. When the output power of the wind turbine 10 oscillates between the first target power and the second target power for more than 40s or 60s, the first additional torque is controlled to be 0 to ensure the normal operation of the wind turbine 10.

[0092] Please continue to refer to this. Figure 3 In step S103, based on the first additional torque, the output power of the wind turbine is controlled to be between or equal to the first target power and the second target power.

[0093] When the frequency change of the power grid is positive, the first additional torque calculated above for the positive frequency change of the power grid is applied to the grid-side converter, so that the output power of the wind turbine is less than or equal to the second target power. Due to the rebound increase of the power of the wind turbine after virtual inertia control, the output power of the wind turbine is greater than the first target power, and thus the output power of the wind turbine is between or equal to the second target power.

[0094] When the frequency change of the power grid is negative, the first additional torque calculated above for the negative frequency change of the power grid is applied to the grid-side converter, so that the output power of the wind turbine is greater than or equal to the second target power. Due to the rebound decrease of the power of the wind turbine after virtual inertia control, the output power of the wind turbine is less than the first target power, and thus the output power of the wind turbine is between or equal to the first target power and the second target power.

[0095] The wind turbine control method provided in this application embodiment controls the wind turbine to output a first target power by performing virtual inertia control on the wind turbine, thereby providing inertia support to the power grid. After a first set duration of virtual inertia control, the output power of the wind turbine is controlled to be between or equal to the second target power. By limiting the output power of the wind turbine with a first additional torque, it is possible to prevent the wind turbine from affecting the power grid frequency again after the inertia support ends, while ensuring the stable operation of the wind turbine.

[0096] Figure 8 The diagram shown is a block diagram of one embodiment of a wind turbine control system 800. The control system includes one or more processors 801 for implementing control methods. In some embodiments, the control system 800 may include a computer-readable storage medium 804, which may store a program that can be called by the processor 801, and may include a non-volatile storage medium. In some embodiments, the control system 800 may include memory 803 and an interface 802. In some embodiments, the control system 800 may also include other hardware depending on the specific application.

[0097] The computer-readable storage medium 804 of this application embodiment stores a program that, when executed by a processor, implements a control method.

[0098] This application may take the form of a computer program product implemented on one or more storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing program code. Computer-readable storage media include permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information may be computer-readable instructions, data structures, program modules, or other data. Examples of computer-readable storage media include, but are not limited to: phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, optical disc read-only memory (CD-ROM), digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.

[0099] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method of controlling a wind turbine, characterized in that, The method comprises: controlling the wind turbine to output a first target power according to the first target power of the wind turbine; determining a first additional torque according to a second target power of the wind turbine and a current electromagnetic torque of the wind turbine after the wind turbine is controlled by the virtual inertia control for a first set time length; controlling the output power of the wind turbine to be between the first target power and the second target power or equal to the second target power according to the first additional torque; wherein one of the first target power and the second target power is greater than the current power of the wind turbine, and the other is less than the current power of the wind turbine; the determining of the first additional torque according to the second target power of the wind turbine and the current electromagnetic torque of the wind turbine after the wind turbine is controlled by the virtual inertia control for the first set time length comprises: acquiring a second current speed of a wind wheel of the wind turbine after the wind turbine is controlled by the virtual inertia control for the first set time length; if the second current speed is not less than a set speed of the wind wheel of the wind turbine, determining a second target torque of the wind turbine after the wind turbine is controlled by the virtual inertia control according to the second target power; and determining the first additional torque according to the current electromagnetic torque and the second target torque; wherein when the change of the grid frequency is a positive change, the second target power is greater than the current power of the wind turbine, and the current electromagnetic torque is not greater than the second target torque; when the change of the grid frequency is a negative change, the second target power is less than the current power of the wind turbine, and the current electromagnetic torque is not less than the second target torque.

2. The control method of a wind turbine generator according to claim 1, characterized by, the controlling of the wind turbine to output the first target power according to the first target power of the wind turbine comprises: acquiring a change rate and a change amount of a current grid frequency relative to a target grid frequency; if the change rate and the change amount meet a triggering condition of the wind turbine being controlled by the virtual inertia control, controlling the wind turbine to be controlled by the virtual inertia control.

3. The control method of a wind turbine generator according to claim 2, characterized by, the triggering condition of the wind turbine being controlled by the virtual inertia control comprises: the change rate of the current grid frequency lasting for a second set time length, the change amount of the current grid frequency reaching a set value, an interval time length from the last time of being controlled by the virtual inertia control reaching a third set time length, and the wind turbine being in a normal power generation state.

4. The control method of a wind turbine generator according to claim 2, characterized by, the method further comprises: if the change rate and the change amount meet the triggering condition of the wind turbine being controlled by the virtual inertia control, before the wind turbine is controlled by the virtual inertia control, determining a second additional torque according to the change rate and the change amount, and controlling the wind turbine to output a third target power according to the second additional torque; wherein the third target power is greater than the first target power.

5. The method of controlling a wind turbine generator according to claim 1, wherein, the controlling of the wind turbine to output the first target power according to the first target power of the wind turbine comprises: acquiring a first current speed of a wind wheel of the wind turbine when the wind turbine is controlled by the virtual inertia control; If the first current rotating speed is less than a set rotating speed of a wind wheel of the wind turbine, the wind turbine is controlled to exit the virtual inertia control.

6. The method of controlling a wind turbine generator according to claim 1, wherein, The first additional torque is determined according to a second target power of the wind turbine and a current electromagnetic torque of the wind turbine after the virtual inertia control is performed for the first set time length, and the determining the first additional torque comprises: A second current rotating speed of the wind wheel of the wind turbine is obtained after the virtual inertia control is performed for the first set time length. If the second current rotating speed is less than the set rotating speed of the wind wheel of the wind turbine, the first additional torque is controlled to be 0.

7. The method of controlling a wind turbine generator according to claim 1, wherein, Further comprising: A third current rotating speed of the wind wheel of the wind turbine is obtained before the virtual inertia control is performed on the wind turbine. A first current rotating speed of the wind wheel of the wind turbine is obtained when the virtual inertia control is performed on the wind turbine. The virtual inertia control is performed on the wind turbine according to the first target power of the wind turbine, and the wind turbine outputs the first target power, and the performing the virtual inertia control comprises: A compensation torque is determined according to the first current rotating speed and the third current rotating speed. A third additional torque is determined according to the first target power of the wind turbine and the compensation torque. The wind turbine outputs the first target power according to the third additional torque.

8. A control system for a wind turbine generator characterized by, The wind turbine comprises one or more processors for implementing the control method of the wind turbine according to any one of claims 1-7.

9. A computer-readable storage medium, characterized in that, The wind turbine has a program stored thereon, and the program is executed by the processor to implement the control method of the wind turbine according to any one of claims 1-7.

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