A control system for a wind turbine

Abstract

The application provides a control system of a wind turbine generator, which is arranged in the wind turbine generator. The system comprises an acquisition component, a control component, a first excitation control component and a second excitation control component. The acquisition component is used for acquiring a voltage amplitude of a corresponding converter group of the wind turbine generator and a voltage threshold corresponding to a low voltage ride-through state of the wind turbine generator. When the voltage amplitude is less than the voltage threshold, a first control instruction is generated and sent to the control component. The control component is used for receiving the first control instruction and accessing the first excitation control component and the second excitation control component according to the first control instruction, so as to control excitation of the wind turbine generator through the first excitation control component and the second excitation control component. The second excitation control component introduced in the application increases the equivalent resistance of the rotor side equivalent circuit, accelerates the decay of the transient flux linkage, reduces the peak value of the rotor current in the voltage drop process, and improves the fault ride-through capability of the wind turbine generator.

Description

Technical Field

[0001] This invention relates to the field of power generation technology, and in particular to a control system for a wind turbine. Background Technology

[0002] Currently, wind turbines are widely used in power generation. However, wind turbines are very sensitive to grid faults. In the event of a fault, the generator-side converter has limited control over the doubly-fed generator, resulting in a weak fault ride-through capability. Therefore, in order to ensure safe operation, wind turbines must have low-voltage ride-through capability.

[0003] However, in related technologies, when a grid voltage dip occurs, the rotor of a doubly-fed generator unit will experience overcurrent and overvoltage. For mild voltage dips, fault ride-through operation is often achieved by improving the control strategy and using demagnetization control. This involves using the rotor magnetic field to counteract the transient components in the stator magnetic field and accelerating the attenuation of the DC component of the stator flux linkage to limit the large stator and rotor currents during the fault. However, the aforementioned technologies cannot accelerate the attenuation of transient flux linkages or reduce the peak value of the rotor current.

[0004] Therefore, how to accelerate the decay of transient flux linkage and reduce the peak value of rotor current during voltage dips in order to improve the fault ride-through capability of doubly-fed wind turbines has become an urgent problem to be solved. Summary of the Invention

[0005] This application provides a control system for wind turbines that can accelerate the decay of transient flux during voltage dips, reduce the peak value of rotor current, and improve the fault ride-through capability of doubly-fed wind turbines.

[0006] According to a first aspect of this application, a control system for a wind turbine generator is provided. The control system is disposed within the wind turbine generator, and the system includes: an acquisition component, a control component, a first excitation control component, and a second excitation control component. The acquisition component is configured to acquire the voltage amplitude of a converter group corresponding to the wind turbine generator and a voltage threshold corresponding to a low-voltage ride-through state of the wind turbine generator; and, in response to the voltage amplitude being less than the voltage threshold, to generate a first control command and send it to the control component. The control component is configured to receive the first control command and, according to the first control command, connect to the first excitation control component and the second excitation control component to perform excitation control on the wind turbine generator through the first excitation control component and the second excitation control component.

[0007] In addition, the control system of a wind turbine according to the above embodiments of this application may also have the following additional technical features:

[0008] According to one embodiment of this application, the acquisition component is further configured to: acquire the grid connection point voltage of the wind turbine generator, so as to acquire the voltage amplitude based on the grid connection point voltage.

[0009] According to one embodiment of this application, the acquisition component is further configured to: acquire the rated voltage of the wind turbine generator, so as to acquire the voltage threshold based on the rated voltage.

[0010] According to one embodiment of this application, the acquisition component is further configured to reacquire the voltage amplitude to obtain an updated voltage amplitude; and, in response to the updated voltage amplitude being greater than or equal to the voltage threshold, generate a second control command and send it to the control component; the control component is further configured to receive the second control command and disconnect the connection with the second excitation control component according to the second control command, so as to perform excitation control on the wind turbine through the first excitation control component.

[0011] According to one embodiment of this application, the acquisition component is further configured to acquire a first current value and a first voltage value of the first rotor of the first excitation control component; and, based on the first current value and the first voltage value, acquire a second current value and a second voltage value of the second rotor of the second excitation control component, and send the second current value and the second voltage value to the control component; the control component is further configured to receive the second current value and the second voltage value to control the second excitation control component to perform excitation control on the wind turbine based on the second current value and the second voltage value.

[0012] According to one embodiment of this application, the acquisition component is further configured to: perform coordinate transformation processing on the first current value to obtain a first current component and a second current component corresponding to the first current value; determine the second current value based on the first current component and the second current component; acquire the current difference between the first current value and the second current value, and acquire the second voltage value based on the current difference.

[0013] According to one embodiment of this application, the acquisition component is further configured to: transform the first current value from a three-phase stationary coordinate system to a two-phase stationary coordinate system to obtain a first current intermediate value; and transform the first current intermediate value from a two-phase stationary coordinate system to a two-phase rotating coordinate system to obtain the first current component and the second current component.

[0014] According to one embodiment of this application, the acquisition component is further configured to: acquire a first resistance value of the first rotor of the first excitation control component and / or a second resistance value of the second rotor of the second excitation control component; and acquire a fault ride-through capability prediction result of the wind turbine based on the first resistance value and the second resistance value.

[0015] According to one embodiment of this application, the acquisition component is further configured to: acquire the motor leakage flux coefficient of the wind turbine, the first rotor self-inductance of the first rotor, and the second rotor self-inductance of the second rotor; and acquire the transfer function of the wind turbine based on the motor leakage flux coefficient, the first rotor self-inductance, the second rotor self-inductance, the first resistance value, and the second resistance value.

[0016] The technical solutions provided in this application have at least the following beneficial effects:

[0017] This application provides a control system for a wind turbine that can accelerate the decay of transient flux during voltage dips, reduce the peak value of rotor current, and improve the fault ride-through capability of the doubly-fed wind turbine.

[0018] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0019] The accompanying drawings are provided for a better understanding of this solution and do not constitute a limitation of this application. Wherein:

[0020] Figure 1 A schematic diagram of a wind turbine control system provided in an embodiment of this application;

[0021] Figure 2 A schematic diagram of a wind turbine topology provided in an embodiment of this application;

[0022] Figure 3 A schematic diagram of a wind turbine circuit provided in an embodiment of this application;

[0023] Figure 4 This is a flowchart illustrating a control method for a wind turbine control system provided in an embodiment of this application. Detailed Implementation

[0024] The following description, in conjunction with the accompanying drawings, illustrates exemplary embodiments of this application, including various details to aid understanding. These should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this application. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0025] The control system of the wind turbine generator of this application will be described in detail below using embodiments.

[0026] Figure 1 This is a schematic diagram of the control system of a wind turbine provided in an embodiment of this application.

[0027] like Figure 1 As shown, the wind turbine control system 1000 in this embodiment is installed in the wind turbine. The wind turbine control system 1000 includes: an acquisition component 100, a control component 200, a first excitation control component 300, and a second excitation control component 400.

[0028] The acquisition component 100 is used to acquire the voltage amplitude of the converter group corresponding to the wind turbine and the voltage threshold corresponding to the low voltage ride-through state of the wind turbine; and, in response to the voltage amplitude being less than the voltage threshold, to generate a first control command and send it to the control component 200.

[0029] It should be noted that the converter group includes multiple current transformers, such as the first converter, the second converter, etc.

[0030] A converter is an electrical device that changes the voltage, frequency, number of phases, and other electrical quantities or characteristics of a power supply system.

[0031] It should be noted that the voltage amplitude of the converter group includes the voltage amplitude of each individual converter.

[0032] Low-voltage ride-through refers to the state in which the wind turbine can remain connected to the grid and even provide some reactive power to the grid when the voltage at the grid connection point drops.

[0033] It should be noted that when attempting to obtain the voltage threshold corresponding to the low voltage ride-through state of a wind turbine, one can first obtain the rated voltage of the wind turbine, and then obtain the voltage threshold corresponding to the low voltage ride-through state based on the rated voltage.

[0034] In this embodiment, after obtaining the voltage amplitude of the converter group corresponding to the wind turbine and the voltage threshold corresponding to the low-voltage ride-through state of the wind turbine, it can be determined whether to generate a first control command based on the relationship between the voltage amplitude and the voltage threshold. Optionally, when the voltage amplitude is less than the voltage threshold, the first control command is generated; alternatively, when the voltage amplitude is greater than or equal to the voltage threshold, the voltage amplitude of the converter group corresponding to the wind turbine and the voltage threshold corresponding to the low-voltage ride-through state of the wind turbine are re-obtained.

[0035] Furthermore, after generating the control command, the acquisition component 100 sends the first control command to the control component 200.

[0036] The control component 200 is used to receive a first control command and simultaneously connect to the first excitation control component 300 and the second excitation control component 400 according to the first control command, so as to perform excitation control on the wind turbine through the first excitation control component 300 and the second excitation control component 400.

[0037] In this embodiment of the application, after the acquisition component 100 sends the first control command to the control component 200, the control component 200 receives the first control command.

[0038] Furthermore, after receiving the first control command, the control component 200 can connect to the first excitation control component 300 and the second excitation control component 400 according to the first control command, so as to perform excitation control on the wind turbine through the first excitation control component 300 and the second excitation control component 400.

[0039] Among them, excitation control refers to controlling the supply of rotor power to the generator rotor.

[0040] This application provides a control system for a wind turbine generator set. The control system, installed within the wind turbine generator set, includes: an acquisition component, a control component, a first excitation control component, and a second excitation control component. The acquisition component is used to acquire the voltage amplitude of the converter group corresponding to the wind turbine generator set and the voltage threshold corresponding to the low-voltage ride-through state of the generator set; and, in response to the voltage amplitude being less than the voltage threshold, to generate a first control command and send it to the control component. The control component is used to receive the first control command and, according to the first control command, connect to the first excitation control component and the second excitation control component to perform excitation control on the wind turbine generator set through the first and second excitation control components. Therefore, the introduction of the second excitation control component in this application increases the equivalent resistance of the rotor-side equivalent circuit, accelerates the attenuation of transient flux linkage, and reduces the peak value of the rotor current during voltage dips, thereby improving the fault ride-through capability of the doubly-fed induction generator (DFIG) wind turbine generator set.

[0041] In some embodiments, the acquiring component 100 is further configured to: acquire the grid connection point voltage of the wind turbine generator, so as to acquire the voltage amplitude based on the grid connection point voltage.

[0042] It should be noted that when obtaining the grid connection point voltage of a wind turbine, the grid connection point voltage of the wind turbine can be measured directly to obtain the grid connection point voltage.

[0043] For example, such as Figure 2 As shown, 1-voltage measurement point, 2-grid-side converter, 3-machine-side converter, 4-rotor current measurement point, 5-grid-side bridge current measurement point, 6-generator, 7-wind turbine grid connection point power supply. Voltage measurement can be performed at location 1 to obtain the grid connection point voltage.

[0044] Furthermore, after obtaining the grid connection point voltage of the wind turbine, the voltage amplitude of the corresponding converter group of the wind turbine can be obtained based on the grid connection point voltage.

[0045] In some embodiments, the acquiring component 100 is further configured to: acquire the rated voltage of the wind turbine generator to acquire a voltage threshold based on the rated voltage.

[0046] The rated voltage of a wind turbine is the voltage of the wind turbine under normal operating conditions.

[0047] It should be noted that the voltage of the wind turbine under normal operating conditions can be read to obtain the rated voltage of the wind turbine.

[0048] For example, if the voltage of a wind turbine is U1 when it is operating normally, then voltage U1 can be used as the rated voltage.

[0049] It should be noted that this application does not limit the specific method for obtaining the voltage threshold based on the rated voltage, and it can be set according to the actual situation.

[0050] Optionally, after obtaining the rated voltage, the mapping relationship between the rated voltage and the voltage threshold can be queried to obtain the voltage threshold.

[0051] Optionally, after obtaining the rated voltage, a preset ratio between the rated voltage and the voltage threshold can be queried to obtain the voltage threshold.

[0052] In some embodiments, the acquiring component 100 is further configured to: acquire a pre-set target coefficient and use the product of the rated voltage and the target coefficient as a voltage threshold.

[0053] It should be noted that the target coefficient corresponding to the wind turbine can be set according to the actual situation. For example, it can be set to 0.9; or, for another example, it can be set to 0.85.

[0054] Furthermore, after obtaining the rated voltage and target coefficient of the wind turbine, the voltage threshold of the wind turbine can be obtained. For example, 0.9 times U1 can be used as the voltage threshold; or, for another example, 0.85 times U1 can be used as the voltage threshold.

[0055] In some embodiments, the acquisition component 100 is further configured to: reacquire the voltage amplitude to obtain an updated voltage amplitude; and, in response to the updated voltage amplitude being greater than or equal to a voltage threshold, generate a second control command and send it to the control component 200.

[0056] In this embodiment, after the acquisition component 100 reacquires the voltage amplitude, an updated voltage amplitude can be obtained. Then, based on the relationship between the updated voltage amplitude and the voltage threshold, it can be determined whether to generate a second control command. Optionally, when the updated voltage amplitude is greater than or equal to the voltage threshold, a second control command is generated.

[0057] Furthermore, after generating the second control command, the acquisition component 100 sends the second control command to the control component 200.

[0058] The control component 200 is also used to receive a second control command and disconnect from the second excitation control component 400 according to the second control command, so as to perform excitation control on the wind turbine through the first excitation control component 300.

[0059] In this embodiment of the application, after the acquisition component 100 sends the second control command to the control component 200, the control component 200 receives the second control command.

[0060] Furthermore, according to the second control command, the connection with the second excitation control component 400 is disconnected, so that the wind turbine can be excitation controlled by the first excitation control component 300. In this case, when the wind turbine exits the low voltage ride-through state and the wind turbine restores its active power to the power value corresponding to the actual wind conditions at a preset rate, the second excitation control component 400 is turned off, and the wind turbine can be excitation controlled by the first excitation control component 300.

[0061] It should be noted that the second excitation control component 400 operates during the entire doubly-fed wind turbine low-voltage ride-through period. When the grid connection point voltage recovers and the wind turbine power recovers to the output power corresponding to the actual wind conditions, the second excitation control component 400 disconnects.

[0062] In some embodiments, the acquisition component 100 is further configured to acquire a first current value and a first voltage value of the first rotor of the first excitation control component 300; and, based on the first current value and the first voltage value, acquire a second current value and a second voltage value of the second rotor of the second excitation control component 400, and send the second current value and the second voltage value to the control component 200.

[0063] It should be noted that when attempting to obtain the first current value and the first voltage value of the first rotor of the first excitation control component 300, such as Figure 2 As shown, the rotor current at rotor current measurement point 3 of the doubly-fed converter 2 can be directly collected to obtain the first current value; the grid voltage at voltage measurement point 1 of the doubly-fed converter 2 can be directly collected to obtain the first voltage value.

[0064] Furthermore, after obtaining the first current value and the first voltage value, the second current value and the second voltage value of the second rotor of the second excitation control component 400 can be calculated based on the first current value and the first voltage value.

[0065] Furthermore, after acquiring the second current value and the second voltage value, the acquisition component 100 can send the second current value and the second voltage value to the control component 200.

[0066] In some embodiments, the control component 200 is further configured to receive a second current value and a second voltage value to control the second excitation control component 400 to perform excitation control on the wind turbine based on the second current value and the second voltage value.

[0067] In this embodiment of the application, after the acquisition component 100 sends the second current value and the second voltage value to the control component 200, the control component 200 can receive the second current value and the second voltage value, and then control the second excitation control component 400 to perform excitation control on the wind turbine according to the second current value and the second voltage value.

[0068] For example, such as Figure 3 As shown, i rdq * i is the given value of the rotor current; rdq This is the feedback value of the rotor current; u rdq * The rotor voltage setpoint; U rdq E is the initial setpoint for the rotor voltage. dq To generate the rotor-side back electromotive force, when the wind turbine enters the low-voltage ride-through state, a second excitation control component is connected, and the second voltage value output by the second excitation control component is superimposed on the initial rotor voltage setpoint U. rdq (At the first voltage value) to perform excitation control on the wind turbine.

[0069] In some embodiments, the acquisition component 100 is further configured to: perform coordinate transformation processing on the first current value to obtain a first current component and a second current component corresponding to the first current value; determine a second current value based on the first current component and the second current component; acquire the current difference between the first current value and the second current value, and acquire a second voltage value based on the current difference.

[0070] In some embodiments, the acquisition component 100 is further configured to: transform the first current value from a three-phase stationary coordinate system to a two-phase stationary coordinate system to obtain a first current intermediate value; and transform the first current intermediate value from a two-phase stationary coordinate system to a two-phase rotating coordinate system to obtain a first current component and a second current component.

[0071] It should be noted that when attempting to transform the first current value from a three-phase stationary coordinate system to a two-phase stationary coordinate system in order to obtain the intermediate value of the first current, the transformation matrix from a three-phase stationary coordinate system to a two-phase stationary coordinate system can be used.

[0072]

[0073] It should be noted that when attempting to transform the first current value from a two-phase stationary coordinate system to a two-phase rotating coordinate system in order to obtain the first current component and the second current component, the transformation matrix from the two-phase stationary coordinate system to the two-phase rotating coordinate system can be used.

[0074]

[0075] Furthermore, after coordinate transformation, the first current component and the second current component, namely the rotor d-axis and q-axis current values, can be obtained. Under the traditional excitation control strategy, only the first excitation control component 300 is connected, and then the virtual resistance excitation controller (second excitation control component 400) is connected. The difference between the actual sampled rotor d-axis and q-axis current values ​​and the rotor current d-axis and q-axis setpoints is input to the virtual resistance excitation controller (second excitation control component 400). At the same time, the output of the virtual resistance controller (second excitation control component 400) is superimposed on the initial setpoints of the rotor voltage d-axis and q-axis to obtain the rotor voltage d-axis and q-axis setpoints.

[0076] In some embodiments, the acquisition component 100 is further configured to: acquire a first resistance value of the first rotor of the first excitation control component 300 and / or a second resistance value of the second rotor of the second excitation control component 400; and acquire a fault ride-through capability prediction result of the wind turbine based on the first resistance value and the second resistance value.

[0077] It should be noted that when the wind turbine is in a low voltage ride-through state, the second resistor of the second rotor of the second excitation control component 400 is connected, and when the wind turbine is not in a low voltage ride-through state, the second resistor of the second rotor of the second excitation control component 400 is not connected or is disconnected.

[0078] Furthermore, when the wind turbine is in a low voltage ride-through state, the connection of the second resistor of the second rotor of the second excitation control component 400 can accelerate the attenuation of transient flux and reduce the peak value of rotor current during voltage drop, thereby improving the fault ride-through capability of the doubly-fed wind turbine.

[0079] In this embodiment, the fault ride-through capability prediction result of the wind turbine can be obtained based on the first resistance value and the second resistance value. Examples include the fault ride-through capability level, transient flux decay rate, and total resistance value.

[0080] In some embodiments, the acquiring component 100 is further configured to: acquire the motor leakage flux coefficient of the wind turbine, the first rotor self-inductance of the first rotor and the second rotor self-inductance of the second rotor; and acquire the transfer function of the wind turbine based on the motor leakage flux coefficient, the first rotor self-inductance, the second rotor self-inductance, the first resistance value and the second resistance value.

[0081] The leakage flux coefficient is the ratio of the total magnetic flux generated by the magnet (permanent magnet or electromagnet) in the magnetic circuit to the useful magnetic flux.

[0082] It should be noted that when obtaining the self-inductance of the first rotor, the formula can be used: Ψ1=N1Φ1, where Ψ1 is the self-inductance of the first rotor, N1 is the number of turns of the first rotor coil, and Φ1 is the magnetic flux per turn of the coil.

[0083] It should be noted that when obtaining the self-inductance of the second rotor, the formula can be used: Ψ2=N2Φ2, where Ψ2 is the self-inductance of the second rotor, N2 is the number of turns of the second rotor coil, and Φ2 is the magnetic flux per turn of the coil.

[0084] Furthermore, after obtaining the motor leakage flux coefficient, first rotor self-inductance, second rotor self-inductance, first resistance value, and second resistance value of the wind turbine, the transfer function of the wind turbine can be obtained.

[0085] In this embodiment of the application, when attempting to obtain the transfer function of a wind turbine, it can be obtained according to the following formula.

[0086]

[0087] Where σ is the leakage flux coefficient of the wind turbine generator, and L rRr is the total self-inductance determined based on the self-inductance of the first rotor and the self-inductance of the second rotor, and Rr is the total resistance value determined based on the first resistance value and the second resistance value.

[0088] Therefore, the control system of the wind turbine provided in this application introduces a second resistor, which increases the equivalent resistance of the rotor-side equivalent circuit, accelerates the attenuation of transient flux, reduces the peak value of rotor current during voltage drop, and improves the fault ride-through capability of the doubly-fed wind turbine.

[0089] In summary, the fault ride-through capability of the doubly-fed wind turbine can be improved by introducing a second excitation control component, which is the control system for the wind turbine proposed in this application.

[0090] For the second excitation control component, such as Figure 4 As shown, optionally, the grid connection point voltage and the current of the first rotor of the wind turbine can be obtained, and the voltage amplitude of the wind turbine can be obtained according to the grid connection point voltage. Then, the voltage amplitude of the wind turbine is compared with 90% of the rated voltage amplitude. If the voltage amplitude of the wind turbine is less than or equal to 90% of the rated voltage amplitude, the wind turbine enters the low voltage ride-through state; otherwise, it operates normally. If the wind turbine is in the low voltage ride-through state, the voltage amplitude of the wind turbine is continuously monitored and compared with 91% of the rated voltage amplitude. If the voltage amplitude of the wind turbine is greater than 91% of the rated voltage amplitude, the wind turbine exits the low voltage ride-through state.

[0091] Furthermore, when the wind turbine enters the low-voltage ride-through state, the virtual resistance excitation controller (second excitation control component) is activated, and its output is superimposed on the initial setpoint of the first rotor voltage. This accelerates the decay of transient flux and reduces the peak value of the rotor current during voltage dips, which helps improve the fault ride-through capability of the doubly-fed wind turbine. When the wind turbine exits the low-voltage ride-through state and restores its active power to the power value corresponding to the actual wind conditions at a specified rate, the virtual resistance excitation controller (second excitation control component) is turned off, and the wind turbine resumes the traditional excitation control strategy.

[0092] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this application can be achieved, and this is not limited herein.

[0093] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A control system for a wind turbine generator, characterized in that, The control system is installed in the wind turbine generator set. The system includes: an acquisition component, a control component, a first excitation control component, and a second excitation control component; wherein... The acquisition component is used to acquire the voltage amplitude of the converter group corresponding to the wind turbine and the voltage threshold corresponding to the low voltage ride-through state of the wind turbine; and, in response to the voltage amplitude being less than the voltage threshold, to generate a first control command and send it to the control component. The control component is used to receive the first control command and connect to the first excitation control component and the second excitation control component according to the first control command, so as to perform excitation control on the wind turbine through the first excitation control component and the second excitation control component. The acquisition component is further configured to acquire a first current value and a first voltage value of the first rotor of the first excitation control component; and, based on the first current value and the first voltage value, acquire a second current value and a second voltage value of the second rotor of the second excitation control component, and send the second current value and the second voltage value to the control component. The control component is further configured to receive the second current value and the second voltage value, so as to control the second excitation control component to perform excitation control on the wind turbine according to the second current value and the second voltage value; The acquisition component is further configured to reacquire the voltage amplitude to obtain an updated voltage amplitude; and, in response to the updated voltage amplitude being greater than or equal to the voltage threshold, generate a second control command and send it to the control component. The control component is further configured to receive the second control command and disconnect the connection with the second excitation control component according to the second control command, so as to perform excitation control on the wind turbine through the first excitation control component; The acquisition component is also used for: The first current value is subjected to coordinate transformation to obtain the first current component and the second current component corresponding to the first current value. The second current value is determined based on the first current component and the second current component; Obtain the current difference between the first current value and the second current value, and obtain the second voltage value based on the current difference; The acquisition component is also used for: The first current value is transformed from a three-phase stationary coordinate system to a two-phase stationary coordinate system to obtain the intermediate value of the first current. The first current intermediate value is transformed from a two-phase stationary coordinate system to a two-phase rotating coordinate system to obtain the first current component and the second current component.

2. The control system according to claim 1, wherein, The acquisition component is also used for: Obtain the grid connection point voltage of the wind turbine generator, and obtain the voltage amplitude based on the grid connection point voltage.

3. The control system according to claim 1 or 2, wherein, The acquisition component is also used for: Obtain the rated voltage of the wind turbine generator, and obtain the voltage threshold based on the rated voltage.

4. The control system according to claim 3, wherein, The acquisition component is also used for: Obtain a pre-set target coefficient, and use the product of the rated voltage and the target coefficient as the voltage threshold.

5. The control system according to claim 1, wherein, The acquisition component is also used for: Obtain the first resistance value of the first rotor of the first excitation control component and / or the second resistance value of the second rotor of the second excitation control component; Based on the first resistance value and the second resistance value, the fault ride-through capability prediction result of the wind turbine is obtained.

6. The control system according to claim 5, wherein, The acquisition component is also used for: Obtain the motor leakage flux coefficient of the wind turbine, the first rotor self-inductance of the first rotor, and the second rotor self-inductance of the second rotor; The transfer function of the wind turbine is obtained based on the motor leakage flux coefficient, the first rotor self-inductance, the second rotor self-inductance, the first resistance value, and the second resistance value.

Images