Electromechanical transient simulation method and system for wind turbine dc capacitor

Abstract

The application discloses a kind of for wind turbine generator unit direct current capacitor electromechanical transient simulation method and system, belong to power system electromechanical transient simulation technical field.The method of the present application, including: the correction of the capacitor basic value, obtain modified capacitor basic value;Judge whether wind turbine generator unit enters high voltage ride-through state or low voltage ride-through state;Based on the preset correction principle and the direct current voltage on-off setting value, the capacitor value is corrected to obtain the modified capacitor value;The electromechanical transient simulation is carried out by the determined capacitor value.Compared with not considering direct current capacitor, it is more close to actual equipment characteristics, can simulate Chopper switching process and direct current voltage dynamic process, and the power value after active power recovery is different due to different direct current voltage;Compared with the case where the capacitor is not processed, for the simulation of transient fault condition under weak grid system, the value is more stable, and the simulation value does not diverge or distort.

Description

Technical Field

[0001] This invention relates to the field of electromechanical transient simulation technology for power systems, and more specifically, to an electromechanical transient simulation method and system for DC capacitors of wind turbine generators. Background Technology

[0002] Electromechanical transient simulation of large power grids is crucial for understanding grid characteristics, analyzing planning schemes, and determining operational modes. Currently, existing electromechanical transient simulation models for wind turbines are relatively simple, neglecting the dynamic characteristics of key internal state variables and failing to accurately reflect the response characteristics of actual equipment under various disturbance conditions. While more refined modeling methods consider the influence of control system inner loops and DC capacitance, the large simulation step size at the electromechanical scale cannot match the parameters reflecting rapidly changing internal characteristics such as DC capacitance and inner loop control, leading to distorted calculation results and affecting the accuracy of the overall simulation model. Our research focuses on how to consider more internal dynamic characteristics in electromechanical transient simulation while maintaining the accuracy required for the appropriate simulation step size. Summary of the Invention

[0003] To address the above problems, this invention proposes an electromechanical transient simulation method for DC capacitors in wind turbine generators, comprising:

[0004] During the initialization and operation phase of the electromechanical transient simulation, the basic value of the DC capacitor is screened in order to correct the basic value of the capacitor and obtain the corrected basic value of the capacitor.

[0005] During the simulation phase of the electromechanical transient simulation, the DC voltage switching settings in the Chopper protection of the wind turbine are obtained. Based on the terminal voltage of the wind turbine and the high voltage ride-through or low voltage ride-through voltage threshold, it is determined whether the wind turbine has entered the high voltage ride-through state or the low voltage ride-through state.

[0006] When it is determined that the wind turbine has entered the high voltage ride-through state or the low voltage ride-through state, a modification mark is set for the capacitance value of the DC capacitor, and the capacitance value is modified based on the preset correction principle and the DC voltage switching setting to obtain the modified capacitance value.

[0007] The capacitance value of the DC capacitor used in the electromechanical transient simulation is determined by comparing the base value and the modified capacitance value, and the electromechanical transient simulation is performed using the determined capacitance value.

[0008] Optionally, the baseline capacitance value of the DC capacitor is screened to correct the baseline capacitance value. Specifically, the baseline capacitance value of the DC capacitor is screened, and the minimum value found is corrected.

[0009] Optionally, if the DC voltage enable / disable setting in the Chopper protection of the wind turbine cannot be obtained, the default value shall be used.

[0010] Optionally, if the wind turbine has not entered the high voltage ride-through state or low voltage ride-through state, the capacitor value used for electromechanical transient simulation shall be the modified base value.

[0011] Optionally, a preset correction principle is set: the DC capacitor after correction of the capacitance value needs at least 3 electromechanical transient simulation steps to complete the capacitor charging or discharging.

[0012] Optionally, if the corrected capacitor value is greater than the base corrected capacitor value, the electromechanical transient simulation uses the corrected capacitor value until the high-voltage ride-through or low-voltage ride-through ends and the active power recovery ends, and the system enters normal operation. Then, the corrected capacitor value is restored to the base corrected capacitor value, and the capacitor modification mark is canceled. Otherwise, the electromechanical transient simulation uses the base corrected capacitor value.

[0013] Furthermore, this invention also proposes an electromechanical transient simulation system for DC capacitors of wind turbine generators, comprising:

[0014] The first correction unit is used to screen the basic value of the DC capacitor during the initialization and operation phase of the electromechanical transient simulation, so as to correct the basic value of the capacitor and obtain the corrected basic value of the capacitor.

[0015] The judgment unit is used to obtain the DC voltage enable / disable setting value in the Chopper protection of the wind turbine during the simulation phase of the electromechanical transient simulation, and to determine whether the wind turbine has entered the high voltage ride-through state or the low voltage ride-through state based on the wind turbine terminal voltage and the high voltage ride-through or low voltage ride-through voltage threshold.

[0016] The second correction unit is used to set a modification flag for the capacitance value of the DC capacitor when it is determined that the wind turbine has entered the high voltage ride-through state or the low voltage ride-through state, and to correct the capacitance value based on the preset correction principle and the DC voltage switching setting to obtain the corrected capacitance value.

[0017] The simulation unit is used to determine the capacitance value of the DC capacitor used in the electromechanical transient simulation by comparing the base value and the modified capacitance value, and to perform the electromechanical transient simulation using the determined capacitance value.

[0018] Optionally, the baseline capacitance value of the DC capacitor is screened to correct the baseline capacitance value. Specifically, the baseline capacitance value of the DC capacitor is screened, and the minimum value found is corrected.

[0019] Optionally, if the DC voltage enable / disable setting in the Chopper protection of the wind turbine cannot be obtained, the default value shall be used.

[0020] Optionally, if the wind turbine has not entered the high voltage ride-through state or low voltage ride-through state, the capacitor value used for electromechanical transient simulation shall be the modified base value.

[0021] Optionally, a preset correction principle is set: the DC capacitor after correction of the capacitance value needs at least 3 electromechanical transient simulation steps to complete the capacitor charging and discharging.

[0022] Optionally, if the corrected capacitor value is greater than the base corrected capacitor value, the electromechanical transient simulation uses the corrected capacitor value until the high-voltage ride-through or low-voltage ride-through ends and the active power recovery ends, and the system enters normal operation. Then, the corrected capacitor value is restored to the base corrected capacitor value, and the capacitor modification mark is canceled. Otherwise, the electromechanical transient simulation uses the base corrected capacitor value.

[0023] In another aspect, the present invention also provides a computing device, comprising: one or more processors;

[0024] A processor is used to execute one or more programs;

[0025] When the one or more programs are executed by the one or more processors, the method described above is implemented.

[0026] In another aspect, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed, implements the method described above.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] This invention provides an electromechanical transient simulation method for DC capacitors of wind turbine generators, comprising: during the initialization and operation phase of the electromechanical transient simulation, screening the baseline capacitance value of the DC capacitor to correct the baseline capacitance value and obtain a corrected baseline capacitance value; during the simulation phase of the electromechanical transient simulation, obtaining the DC voltage enable / disable setting value in the Chopper protection of the wind turbine generator, and determining whether the wind turbine generator has entered a high voltage ride-through state or a low voltage ride-through state based on the wind turbine generator terminal voltage and the high voltage ride-through or low voltage ride-through voltage threshold; when it is determined that the wind turbine generator has entered a high voltage ride-through state or a low voltage ride-through state, setting a modification flag for the capacitance value of the DC capacitor, and correcting the capacitance value based on a preset correction principle and the DC voltage enable / disable setting value to obtain a corrected capacitance value; by comparing the corrected baseline capacitance value and the corrected capacitance value, determining the capacitance value of the DC capacitor used in the electromechanical transient simulation, and performing the electromechanical transient simulation using the determined capacitance value. Compared to the case where DC capacitors are not considered, this invention is closer to the characteristics of actual equipment and can simulate the Chopper switching process and the dynamic process of DC voltage. The power value after active power recovery also varies due to different DC voltages. Compared to the case where no capacitors are treated, the simulation of transient faults in weak network systems is more stable and will not result in divergence or distortion of simulation values. Attached Figure Description

[0029] Figure 1 This is a flowchart of the method of the present invention;

[0030] Figure 2 This is a flowchart illustrating the implementation of the method of the present invention;

[0031] Figure 3 This is a comparison chart of the DC voltage simulation results when the method of the present invention is implemented and when the DC capacitor is not considered.

[0032] Figure 4 This is a comparison chart of the active power simulation results of the method of the present invention and the result without considering the DC capacitor;

[0033] Figure 5 This is a comparison diagram of the simulation effects of implementing the method of the present invention and when the capacitor is not treated in any way;

[0034] Figure 6 This is a structural diagram of the system of the present invention. Detailed Implementation

[0035] Exemplary embodiments of the invention will now be described with reference to the accompanying drawings. However, the invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0036] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0037] Example 1:

[0038] This invention proposes an electromechanical transient simulation method for DC capacitors in wind turbine generators, such as... Figure 1 As shown, it includes:

[0039] Step 1: In the initialization and operation phase of electromechanical transient simulation, the basic value of DC capacitor is screened to correct the basic value of the capacitor and obtain the corrected basic value of the capacitor.

[0040] Step 2: In the simulation phase of the electromechanical transient simulation, obtain the DC voltage switching setting value in the Chopper protection of the wind turbine. Based on the wind turbine terminal voltage and the high voltage ride-through or low voltage ride-through voltage threshold, determine whether the wind turbine has entered the high voltage ride-through state or the low voltage ride-through state.

[0041] Step 3: When it is determined that the wind turbine has entered the high voltage ride-through state or the low voltage ride-through state, set the modification mark of the DC capacitor value, and modify the capacitor value based on the preset correction principle and the DC voltage switching setting to obtain the modified capacitor value.

[0042] Step 4: By comparing the base value and the modified capacitor value, determine the capacitance value of the DC capacitor used in the electromechanical transient simulation, and perform the electromechanical transient simulation using the determined capacitance value.

[0043] Specifically, screening is performed on the baseline capacitance value of the DC capacitor to correct the baseline capacitance value. This involves screening the baseline capacitance value of the DC capacitor and correcting the minimum value found during the screening.

[0044] If the DC voltage enable / disable setting in the Chopper protection of the wind turbine cannot be obtained, the default value shall be used.

[0045] If the wind turbine has not entered the high voltage ride-through state or low voltage ride-through state, the capacitor value used for electromechanical transient simulation shall be the modified base value.

[0046] The preset correction principle is as follows: the DC capacitor after correction of the capacitance value needs at least 3 electromechanical transient simulation steps to complete the capacitor charging and discharging.

[0047] If the corrected capacitor value is greater than the base corrected capacitor value, the electromechanical transient simulation will use the corrected capacitor value until the high-voltage ride-through or low-voltage ride-through ends and the active power recovery ends and the system enters normal operation. Then, the corrected capacitor value will be restored to the base corrected capacitor value and the capacitor modification mark will be canceled. Otherwise, the electromechanical transient simulation will use the base corrected capacitor value.

[0048] The invention will be further described below with reference to specific implementations:

[0049] This invention dynamically adjusts the capacitor value based on factors such as the DC voltage protection setting parameters of the wind turbine, its operating status, and the simulation step size to improve the ability to simulate capacitor dynamics under electromechanical transient simulation. By back-calculating the capacitor value adapted to the conditions of the electromechanical transient simulation based on the operating status and simulation step size during the simulation process, the invention ensures that the simulation calculations are reasonable during transient simulation. The main key point of this invention is to adjust the capacitor parameters in real time according to the dynamic operating characteristics of the wind turbine, ensuring that the capacitor charging and discharging process is completed within a few simulation step sizes. Figure 2 As shown, the specific method includes the following steps:

[0050] The first step, the initialization phase, involves screening the basic capacitor parameters under normal operating conditions. During the initial operation phase, a comprehensive screening of the capacitor parameters is performed, and minimum values ​​are appropriately corrected to ensure that the steady-state simulation results under weak network conditions do not exhibit oscillations. Typically, a minimum capacitor threshold value is set; if the value is less than this threshold, it is modified to a larger value during the initialization phase, thus correcting the basic capacitor parameters to obtain new ones.

[0051] The second step is to obtain the DC voltage setting for enabling / disabling the Chopper protection in the wind turbine generator set. The wind turbine generator set model obtains the voltage setting for enabling / disabling the Chopper protection from the wind turbine generator set Chopper protection control model. If the voltage setting for enabling / disabling is not filled in the wind turbine generator set Chopper protection, the default value is used.

[0052] The third step is to determine in real time whether the wind turbine has entered the high or low voltage ride-through state during the simulation. If it has entered the high or low voltage ride-through state, proceed to the fourth step; otherwise, the capacitor remains calculated according to the basic capacitor parameters.

[0053] The fourth step involves setting a capacitor value modification flag and calculating the corrected capacitor value if the system enters a high or low voltage ride-through state. The basic principle of the specific capacitor value modification method is to ensure that the capacitor charging or discharging process requires at least three electromechanical transient simulation steps (considered as one time period). This is achieved by calculating the capacitor current value from both power conservation and capacitor dynamic equation perspectives, and then using the DC capacitor current to deduce the capacitor value.

[0054] According to the principle of power conservation, the DC capacitor current is equal to the change in active power divided by the DC voltage U. DC Taking a direct-drive wind turbine as an example, the change in active power is based on the active power P during the high and low voltage ride-through period. g_LV With normal active power P g0 Calculation. Based on the capacitor's own dynamic change equation, the DC voltage variable is calculated to complete one discharge cycle, with the Chopper protection setting voltage U being the input voltage. chopper_on With Chopper protection exit voltage setting U chopper_off The difference is calculated using three electromechanical transient simulation steps. The DC voltage change is multiplied by the capacitance value to obtain the average DC current during the discharge cycle. Following the principle that the average DC capacitor current calculated from both aspects is equal, the corrected capacitance value C is calculated. mod The simulation step size is h, and all the above correction calculations use named values.

[0055]

[0056] The fifth step is to compare the corrected capacitance value with the basic capacitance parameter value to determine the capacitance value to be used in the calculation. If the corrected capacitance value is greater than the basic capacitance parameter, the corrected capacitance value will be used in the simulation calculations until the high- and low-voltage ride-through is completed and the system returns to normal operation. In this case, the calculated capacitance value will revert to the basic parameter, and the capacitance modification mark will be removed. Otherwise, the capacitance value will not be corrected, and the calculation will still use the basic capacitance parameter.

[0057] During electromechanical transient simulation, the capacitance parameters in the model are adjusted in real time based on the high and low voltage ride-through conditions and operating status. Although the parameters of the capacitance simulation model may be adjusted in real time during simulation calculation, the historical values ​​of current and voltage from the previous simulation step are not adjusted. The differential equation difference calculation is performed directly in the current step based on the new capacitance value and the historical values ​​from the previous step.

[0058] Compared to ignoring DC capacitance (or treating DC capacitance as infinite), this method more closely reflects the characteristics of actual equipment, simulating the Chopper switching process and dynamic DC voltage processes, with significantly improved results. Figure 3 As shown, the power value after active power recovery varies depending on the DC voltage, and the effect is different for example. Figure 4 As shown, compared to the case where the capacitor is not treated in any way, the simulation of transient fault conditions in weak network systems is more stable, and there is no divergence or distortion in the simulation values. The effect is quite good. Figure 5 As shown.

[0059] Example 2

[0060] This invention also proposes an electromechanical transient simulation system 200 for DC capacitors of wind turbine generators, such as... Figure 6 As shown, it includes:

[0061] The first correction unit 201 is used to screen the basic value of the DC capacitor during the initialization and operation phase of the electromechanical transient simulation, so as to correct the basic value of the capacitor and obtain the corrected basic value of the capacitor.

[0062] Judgment unit 202 is used to obtain the DC voltage enable / disable setting value in the Chopper protection of the wind turbine during the simulation phase of the electromechanical transient simulation, and determine whether the wind turbine has entered the high voltage ride-through state or the low voltage ride-through state based on the wind turbine terminal voltage and the high voltage ride-through or low voltage ride-through voltage threshold.

[0063] The second correction unit 203 is used to set a modification mark for the capacitance value of the DC capacitor when it is determined that the wind turbine has entered the high voltage ride-through state or the low voltage ride-through state, and to correct the capacitance value based on the preset correction principle and the DC voltage switching setting to obtain the corrected capacitance value.

[0064] The simulation unit 204 is used to determine the capacitance value of the DC capacitor used in the electromechanical transient simulation by comparing the base value of the correction capacitor with the correction capacitor value, and to perform the electromechanical transient simulation using the determined capacitance value.

[0065] Specifically, screening is performed on the baseline capacitance value of the DC capacitor to correct the baseline capacitance value. This involves screening the baseline capacitance value of the DC capacitor and correcting the minimum value found during the screening.

[0066] If the DC voltage enable / disable setting in the Chopper protection of the wind turbine cannot be obtained, the default value shall be used.

[0067] If the wind turbine has not entered the high voltage ride-through state or low voltage ride-through state, the capacitor value used for electromechanical transient simulation shall be the modified base value.

[0068] The preset correction principle is as follows: the DC capacitor after correction of the capacitance value needs at least 3 electromechanical transient simulation steps to complete the capacitor charging and discharging.

[0069] If the corrected capacitor value is greater than the base corrected capacitor value, the electromechanical transient simulation will use the corrected capacitor value until the high-voltage ride-through or low-voltage ride-through ends and the active power recovery ends and the system enters normal operation. Then, the corrected capacitor value will be restored to the base corrected capacitor value and the capacitor modification mark will be canceled. Otherwise, the electromechanical transient simulation will use the base corrected capacitor value.

[0070] Example 3:

[0071] Based on the same inventive concept, this invention also provides a computer device, which includes a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in the computer storage medium to implement corresponding method flows or corresponding functions, thereby implementing the steps of the methods in the above embodiments.

[0072] Example 4:

[0073] Based on the same inventive concept, this invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device used to store programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and extended storage media supported by the computer device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, this storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be high-speed RAM or non-volatile memory, such as at least one disk storage device. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the method in the above embodiments.

[0074] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present invention can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0075] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0076] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0077] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0078] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0079] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for electromechanical transient simulation of DC capacitors in wind turbine generators, characterized in that, The method includes: During the initialization and operation phase of the electromechanical transient simulation, the basic value of the DC capacitor is screened in order to correct the basic value of the capacitor and obtain the corrected basic value of the capacitor. During the simulation phase of the electromechanical transient simulation, the DC voltage switching settings in the Chopper protection of the wind turbine are obtained, and the wind turbine terminal voltage and the high voltage ride-through or low voltage ride-through voltage thresholds are used to determine whether the wind turbine has entered the high voltage ride-through state or the low voltage ride-through state. When it is determined that the wind turbine has entered the high voltage ride-through state or the low voltage ride-through state, a modification mark is set for the capacitance value of the DC capacitor, and the capacitance value is modified based on the preset correction principle and the DC voltage switching setting to obtain the modified capacitance value. The capacitance value of the DC capacitor used in the electromechanical transient simulation is determined by comparing the base value and the modified capacitance value, and the electromechanical transient simulation is performed using the determined capacitance value. The screening of the basic capacitance value of the DC capacitor to correct the basic capacitance value specifically involves: screening the basic capacitance value of the DC capacitor and correcting the minimum value found during screening. If the wind turbine has not entered the high voltage ride-through state or low voltage ride-through state, the capacitor value used for electromechanical transient simulation shall be the modified base value. This also includes calculating the corrected capacitance value C. mod : Among them, P g_LV P represents the active power during high and low voltage ride-through. g0 For normal active power, the time variable is 3 electromechanical transient simulation steps with a simulation step size of h. The DC voltage variable is the difference between the Chopper protection on-state voltage setting Uchopper_on and the Chopper protection off-state voltage setting Uchopper_off; DC voltage U DC .

2. The method according to claim 1, characterized in that, If the DC voltage enable / disable setting in the Chopper protection of the wind turbine cannot be obtained, the default value shall be used.

3. The method according to claim 1, characterized in that, The preset correction principle is as follows: the DC capacitor after correction of the capacitance value needs at least 3 electromechanical transient simulation steps to complete the capacitor charging or discharging.

4. The method according to claim 1, characterized in that, If the corrected capacitor value is greater than the base corrected capacitor value, the electromechanical transient simulation will use the corrected capacitor value until the high-voltage ride-through or low-voltage ride-through ends and the active power recovery ends, and the system enters normal operation. Then, the corrected capacitor value will be restored to the base corrected capacitor value and the capacitor modification mark will be canceled. Otherwise, the electromechanical transient simulation will use the base corrected capacitor value.

5. An electromechanical transient simulation system for DC capacitors of wind turbine generators, characterized in that, The system includes: The first correction unit is used to screen the basic value of the DC capacitor during the initialization and operation phase of the electromechanical transient simulation, so as to correct the basic value of the capacitor and obtain the corrected basic value of the capacitor. The judgment unit is used to obtain the DC voltage switching setting value in the Chopper protection of the wind turbine during the simulation phase of the electromechanical transient simulation, and to determine whether the wind turbine has entered the high voltage ride-through state or the low voltage ride-through state based on the wind turbine terminal voltage and the high voltage ride-through or low voltage ride-through voltage threshold. The second correction unit is used to set a modification flag for the capacitance value of the DC capacitor when it is determined that the wind turbine has entered the high voltage ride-through state or the low voltage ride-through state, and to correct the capacitance value based on the preset correction principle and the DC voltage switching setting to obtain the corrected capacitance value. The simulation unit is used to determine the capacitance value of the DC capacitor used in the electromechanical transient simulation by comparing the base value of the correction capacitor with the correction capacitor value, and to perform the electromechanical transient simulation using the determined capacitance value. The screening of the basic capacitance value of the DC capacitor to correct the basic capacitance value specifically involves: screening the basic capacitance value of the DC capacitor and correcting the minimum value found during screening. If the wind turbine has not entered the high voltage ride-through state or low voltage ride-through state, the capacitor value used for electromechanical transient simulation shall be the modified base value. This also includes calculating the corrected capacitance value C. mod : Among them, P g_LV P represents the active power during high and low voltage ride-through. g0 For normal active power, the time variable is 3 electromechanical transient simulation steps with a simulation step size of h. The DC voltage variable is the difference between the Chopper protection on-state voltage setting Uchopper_on and the Chopper protection off-state voltage setting Uchopper_off; DC voltage U DC .

6. The system according to claim 5, characterized in that, If the DC voltage enable / disable setting in the Chopper protection of the wind turbine cannot be obtained, the default value shall be used.

7. The system according to claim 5, characterized in that, The preset correction principle is as follows: the DC capacitor after correction of the capacitance value needs at least 3 electromechanical transient simulation steps to complete the capacitor charging or discharging.

8. The system according to claim 5, characterized in that, If the corrected capacitor value is greater than the base corrected capacitor value, the electromechanical transient simulation will use the corrected capacitor value until the high-voltage ride-through or low-voltage ride-through ends and the active power recovery ends, and the system enters normal operation. Then, the corrected capacitor value will be restored to the base corrected capacitor value and the capacitor modification mark will be canceled. Otherwise, the electromechanical transient simulation will use the base corrected capacitor value.

9. A computer device, characterized in that, include: One or more processors; A processor is used to execute one or more programs; When the one or more programs are executed by the one or more processors, the method described in any one of claims 1-4 is implemented.

10. A computer-readable storage medium, characterized in that, It contains a computer program, which, when executed, implements the method as described in any one of claims 1-4.

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