Electromechanical transient simulation method and system for doubly-fed wind turbine generator

Abstract

The invention discloses an electromechanical transient simulation method and system for a doubly-fed wind turbine generator, and belongs to the technical field of electromechanical transient simulation of a power system. The method comprises the following steps: determining a necessary simulation link according to a simulation time scale and an action frequency band of electromechanical transient simulation of the doubly-fed wind turbine generator, and establishing a simulation module based on the necessary link; establishing a mathematical model of the simulation modules, and establishing an interaction relationship between electrical data and control signals among the simulation modules based on the coupling relationship among the necessary links; and establishing an electromechanical transient simulation model of the doubly-fed wind turbine generator based on the mathematical model and the interaction relationship, and performing electromechanical transient simulation on the doubly-fed wind turbine generator based on the electromechanical transient simulation model. According to the method, a large number of model parameters do not need to be modified, different types of simulation models can be flexibly switched only through selection of the grid-connected interface, and the simulation speed is increased under the condition that it is guaranteed that the simulation precision meets the requirement.

Description

Technical Field

[0001] The present invention relates to the technical field of electromechanical transient simulation of power systems, and more specifically, to an electromechanical transient simulation method and system for a doubly-fed wind turbine generator set. Background Art

[0002] The existing electromechanical transient model of wind turbines is relatively simple, ignoring the dynamic characteristics that can reflect the key state variables inside the equipment. It mainly adopts a controllable current source model, only provides limited control details, and fits the input / output characteristics by adjusting the model parameters. It cannot accurately reflect the complex switching logic and nonlinear response characteristics of the actual equipment under various large disturbance conditions. This simplified modeling of fitting external characteristics introduces large simulation errors when a large number of power electronic equipment are connected to the power grid, which seriously limits the application prospects of electromechanical transient models.

[0003] In recent years, electromagnetic transient simulation has been widely valued and developed. However, the electromagnetic transient simulation model is too detailed and the simulation step size is too small. When performing large power grid simulation calculations, the computing resources and computing time consumed are too huge. Therefore, electromechanical transient analysis is still an important requirement for daily production of power systems, and it is urgent to update the electromechanical transient simulation model and method of wind turbines. Summary of the invention

[0004] In view of the above problems, the present invention proposes an electromechanical transient simulation method for a doubly-fed wind turbine generator system, comprising:

[0005] According to the simulation time scale and action frequency band of the electromechanical transient simulation of the doubly-fed wind turbine generator set, the necessary simulation links are determined, and a simulation module is established based on the necessary links;

[0006] Establishing a mathematical model of the simulation module, and establishing an interactive relationship between electrical data and control signals between the simulation modules based on the coupling relationship between the necessary links;

[0007] An electromechanical transient simulation model of a doubly-fed wind turbine generator set is established based on the mathematical model and the interaction relationship, and an electromechanical transient simulation is performed on the doubly-fed wind turbine generator set based on the electromechanical transient simulation model.

[0008] Optionally, based on the electromechanical transient simulation model, performing electromechanical transient simulation on the doubly-fed wind turbine generator set includes:

[0009] For the electromechanical transient simulation model, different grid-connected interfaces under the xy-axis coordinates are established. By switching the different grid-connected interfaces of the electromechanical transient simulation model, the electromechanical transient simulation model is switched to a detailed electromechanical transient model, a simplified electromechanical transient model with voltage source characteristics, or a simplified electromechanical transient model with current source characteristics. The detailed electromechanical transient model, the simplified electromechanical transient model with voltage source characteristics, or the simplified electromechanical transient model with current source characteristics are initialized and the equation solving steps are performed to perform electromechanical transient simulation on the doubly-fed wind turbine set.

[0010] Optionally, determining the equipment components of the doubly-fed wind turbine generator system that meet the electromechanical time scale, DC voltage time scale and current time scale is a necessary step in the simulation.

[0011] Optional equipment components include:

[0012] Analyze the wind speed link, wind power link, pitch angle control link, primary frequency regulation link, inertia control link, shaft system link, asynchronous motor link, converter link, DC capacitor link, converter current inner loop control link, converter outer loop control link, phase-locked loop link, high and low voltage ride-through strategy link, Chopper protection link and Crowbar protection link.

[0013] Optional, simulation modules, including: optional modules and mandatory modules;

[0014] Among them, the simulation module established for the necessary links in the frequency range of 50 to 200 Hz is an optional module;

[0015] The optional modules include at least one of the following:

[0016] Asynchronous motor detailed model, converter model, DC capacitor model, rotor-side converter current inner loop control model, phase-locked loop model, grid-side converter control model, Chopper protection model and Crowbar protection model;

[0017] The rotor-side converter current inner loop control model is established based on the rotor current deviation outputting a modulation voltage through a proportional-integral link. After the modulation voltage output by the current inner loop control is modulated and limited, the AC side controlled voltage of the rotor-side converter is determined according to the relationship between the modulation amount and the AC and DC voltages of the rotor-side converter.

[0018] The output signal of the Crowbar protection model is used as an enable signal for the inner loop current control output of the rotor-side converter and the modification of the rotor parameters of the asynchronous motor;

[0019] Among them, the simulation model established for the necessary links in the frequency range of 0.1 to 50 Hz is a mandatory module;

[0020] The required modules include: a general link model and a specific link model.

[0021] Optional, general link models, including: wind power model, pitch angle control model, primary frequency regulation model, inertia control model, shaft system model, rotor side converter outer loop control model and high and low voltage ride-through strategy model;

[0022] The meaning of the output signal of the rotor converter outer loop control model is switched according to the model type, which is the rotor current in the detailed model and the total current in the simplified model;

[0023] The high and low voltage ride-through strategy model performs high and low voltage ride-through simulations by three methods: current limiting, changing the current reference output by the outer loop control of the rotor side converter, or changing the outer loop control power reference value.

[0024] Optional, link-specific models, including: wind speed model;

[0025] The wind speed model includes: a gradual wind model, a gust model and a random wind model.

[0026] Optional, detailed electromechanical transient model grid-connected interface, including: stator-side interface and grid-side converter interface;

[0027] Among them, the stator side interface is established through the asynchronous motor stator and rotor voltage equations;

[0028] The current output by the grid-side converter control model is used as a controlled current source to establish a grid-side converter interface.

[0029] Optionally, a controlled current source or a controlled voltage source is used as a grid-connected interface of the simplified electromechanical transient model.

[0030] Optionally, the method further includes: performing parameter fitting and verification on the established multiple types of electromechanical transient simulation models.

[0031] Optionally, perform parameter fitting and verification on the established multiple types of electromechanical transient simulation models, including:

[0032] Through mechanism and simulation tests, the parameters of the electromechanical transient simulation model are classified, key parameters and non-key parameters are determined, the determined key parameters are identified and fitted, and the fitted key parameters are verified through large and small disturbance tests.

[0033] On the other hand, the present invention also proposes an electromechanical transient simulation system for a doubly-fed wind turbine generator system, comprising:

[0034] The initial unit is used to determine the necessary links of the simulation according to the simulation time scale and action frequency band of the electromechanical transient simulation of the doubly-fed wind turbine generator set, and establish a simulation module based on the necessary links;

[0035] A calculation unit, used to establish a mathematical model of the simulation module, and to establish an interactive relationship between electrical data and control signals between the simulation modules based on the coupling relationship between the necessary links;

[0036] The simulation unit is used to establish an electromechanical transient simulation model of the doubly-fed wind turbine generator set based on the mathematical model and the interaction relationship, and to perform electromechanical transient simulation on the doubly-fed wind turbine generator set based on the electromechanical transient simulation model.

[0037] Optionally, based on the electromechanical transient simulation model, performing electromechanical transient simulation on the doubly-fed wind turbine generator set includes:

[0038] For the electromechanical transient simulation model, different grid-connected interfaces under the xy-axis coordinates are established. By switching the different grid-connected interfaces of the electromechanical transient simulation model, the electromechanical transient simulation model is switched to a detailed electromechanical transient model, a simplified electromechanical transient model with voltage source characteristics, or a simplified electromechanical transient model with current source characteristics. The detailed electromechanical transient model, the simplified electromechanical transient model with voltage source characteristics, or the simplified electromechanical transient model with current source characteristics are initialized and the equation solving steps are performed to perform electromechanical transient simulation on the doubly-fed wind turbine set.

[0039] Optionally, the initial unit determines the equipment components of the doubly-fed wind turbine generator set that meet the electromechanical time scale, the DC voltage time scale and the current time scale as a necessary part of the simulation.

[0040] Optional equipment components include:

[0041] Analyze the wind speed link, wind power link, pitch angle control link, primary frequency regulation link, inertia control link, shaft system link, asynchronous motor link, converter link, DC capacitor link, converter current inner loop control link, converter outer loop control link, phase-locked loop link, high and low voltage ride-through strategy link, Chopper protection link and Crowbar protection link.

[0042] Optional, simulation modules, including: optional modules and mandatory modules;

[0043] Among them, the simulation module established for the necessary links in the frequency range of 50 to 200 Hz is an optional module;

[0044] The optional modules include at least one of the following:

[0045] Asynchronous motor detailed model, converter model, DC capacitor model, rotor-side converter current inner loop control model, phase-locked loop model, grid-side converter control model, Chopper protection model and Crowbar protection model;

[0046] The rotor-side converter current inner loop control model is established based on the rotor current deviation outputting a modulation voltage through a proportional-integral link. After the modulation voltage output by the current inner loop control is modulated and limited, the AC side controlled voltage of the rotor-side converter is determined according to the relationship between the modulation amount and the AC and DC voltages of the rotor-side converter.

[0047] The output signal of the Crowbar protection model is used as an enable signal for the inner loop current control output of the rotor-side converter and the modification of the rotor parameters of the asynchronous motor;

[0048] Among them, the simulation model established for the necessary links in the frequency range of 0.1 to 50 Hz is a mandatory module;

[0049] The required modules include: a general link model and a specific link model.

[0050] Optionally, the general link model includes at least one of the following: a wind power model, a pitch angle control model, a primary frequency modulation model, an inertia control model, a shaft system model, a rotor-side converter outer loop control model, and a high and low voltage ride-through strategy model;

[0051] The meaning of the output signal of the rotor converter outer loop control model is switched according to the model type, which is the rotor current in the detailed model and the total current in the simplified model;

[0052] The high and low voltage ride-through strategy model performs high and low voltage ride-through simulations by three methods: current limiting, changing the current reference output by the outer loop control of the rotor side converter, or changing the outer loop control power reference value.

[0053] Optional, link-specific models, including: wind speed model;

[0054] The wind speed model includes: a gradual wind model, a gust model and a random wind model.

[0055] Optional, detailed electromechanical transient model grid-connected interface, including: stator-side interface and grid-side converter interface;

[0056] Among them, the stator side interface is established through the asynchronous motor stator and rotor voltage equations;

[0057] Among them, a grid-side converter interface is established through a controlled current source and a grid interface.

[0058] Optionally, a controlled current source or a controlled voltage source is used as a grid-connected interface of the simplified electromechanical transient model.

[0059] Optionally, the simulation unit is also used to perform parameter fitting and verification on established multiple types of electromechanical transient simulation models.

[0060] Optionally, the simulation unit performs parameter fitting and verification on multiple types of electromechanical transient simulation models, including:

[0061] Through mechanism and simulation tests, the parameters of the electromechanical transient simulation model are classified, key parameters and non-key parameters are determined, the determined key parameters are identified and fitted, and the fitted key parameters are verified through large and small disturbance tests.

[0062] In yet another aspect, the present invention further provides a computing device, comprising: one or more processors;

[0063] a processor for executing one or more programs;

[0064] When the one or more programs are executed by the one or more processors, the above-described method is implemented.

[0065] In yet another aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed, the method described above is implemented.

[0066] Compared with the prior art, the present invention has the following beneficial effects:

[0067] The present invention provides an electromechanical transient simulation method for a doubly-fed wind turbine generator set, comprising: determining the necessary links of the simulation according to the simulation time scale and action frequency band of the electromechanical transient simulation of the doubly-fed wind turbine generator set, and establishing a simulation module based on the necessary links; establishing a mathematical model of the simulation module, and establishing an interactive relationship between electrical data and control signals between the simulation modules based on the coupling relationship between the necessary links; establishing an electromechanical transient simulation model of the doubly-fed wind turbine generator set based on the mathematical model and the interactive relationship, and performing electromechanical transient simulation on the doubly-fed wind turbine generator set based on the electromechanical transient simulation model. The present invention does not require a large number of model parameters to be modified, and different types of simulation models can be flexibly switched only by selecting a grid-connected interface, and the simulation speed is improved while ensuring that the simulation accuracy meets the requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 is a flow chart of the method of the present invention;

[0069] Figure 2 A flow chart of a method for electromechanical transient simulation of a doubly-fed wind turbine generator set according to an embodiment of the method of the present invention;

[0070] Figure 3 It is a structural block diagram of an electromechanical transient model of a doubly-fed wind turbine generator set according to an embodiment of the method of the present invention;

[0071] Figure 4 A detailed electromechanical transient simulation active and reactive power curve diagram of a doubly-fed wind turbine generator set according to an embodiment of the method of the present invention;

[0072] Figure 5 The voltage source characteristic of the doubly-fed wind turbine generator set in the method embodiment of the present invention is simplified by electromechanical transient simulation active and reactive power curves;

[0073] Figure 6 The simplified electromechanical transient simulation active and reactive power curve diagram of the current source characteristics of the doubly-fed wind turbine generator set according to the method embodiment of the present invention;

[0074] Figure 7 It is a structural diagram of the system of the present invention. DETAILED DESCRIPTION

[0075] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0076] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0077] Embodiment 1:

[0078] The present invention proposes a method for electromechanical transient simulation of a doubly-fed wind turbine generator system. Figure 1 As shown, including:

[0079] Step 1: Determine the necessary links of the simulation according to the simulation time scale and action frequency band of the electromechanical transient simulation of the doubly-fed wind turbine generator set, and establish a simulation module based on the necessary links;

[0080] Step 2: Establish a mathematical model of the simulation module, and establish an interactive relationship between electrical data and control signals between the simulation modules based on the coupling relationship between the necessary links;

[0081] Step 3: Establish an electromechanical transient simulation model of the doubly-fed wind turbine generator set based on the mathematical model and the interaction relationship, and perform electromechanical transient simulation on the doubly-fed wind turbine generator set based on the electromechanical transient simulation model.

[0082] Wherein, based on the electromechanical transient simulation model, the electromechanical transient simulation of the doubly-fed wind turbine generator set is performed, including:

[0083] For the electromechanical transient simulation model, different grid-connected interfaces under the xy-axis coordinates are established. By switching the different grid-connected interfaces of the electromechanical transient simulation model, the electromechanical transient simulation model is switched to a detailed electromechanical transient model, a simplified electromechanical transient model with voltage source characteristics, or a simplified electromechanical transient model with current source characteristics. The detailed electromechanical transient model, the simplified electromechanical transient model with voltage source characteristics, or the simplified electromechanical transient model with current source characteristics are initialized and the equation solving steps are performed to perform electromechanical transient simulation on the doubly-fed wind turbine set.

[0084] Among them, determining the equipment components of the doubly-fed wind turbine generator system that meet the electromechanical time scale, DC voltage time scale and current time scale is a necessary part of the simulation.

[0085] Among them, the equipment components include:

[0086] Analyze the wind speed link, wind power link, pitch angle control link, primary frequency regulation link, inertia control link, shaft system link, asynchronous motor link, converter link, DC capacitor link, converter current inner loop control link, converter outer loop control link, phase-locked loop link, high and low voltage ride-through strategy link, Chopper protection link and Crowbar protection link.

[0087] Among them, the simulation module includes: optional modules and mandatory modules;

[0088] Among them, the simulation module established for the necessary links in the frequency range of 50 to 200 Hz is an optional module;

[0089] The optional modules include at least one of the following:

[0090] Asynchronous motor detailed model, converter model, DC capacitor model, rotor-side converter current inner loop control model, phase-locked loop model, grid-side converter control model, Chopper protection model and Crowbar protection model;

[0091] The rotor-side converter current inner loop control model is established based on the rotor current deviation outputting a modulation voltage through a proportional-integral link. After the modulation voltage output by the current inner loop control is modulated and limited, the AC side controlled voltage of the rotor-side converter is determined according to the relationship between the modulation amount and the AC and DC voltages of the rotor-side converter.

[0092] The output signal of the Crowbar protection model is used as an enable signal for the inner loop current control output of the rotor-side converter and the modification of the rotor parameters of the asynchronous motor;

[0093] Among them, the simulation model established for the necessary links in the frequency range of 0.1 to 50 Hz is a mandatory module;

[0094] The required modules include: a general link model and a specific link model.

[0095] Among them, the general link models include: wind power model, pitch angle control model, primary frequency regulation model, inertia control model, shaft system model, rotor side converter outer loop control model and high and low voltage ride-through strategy model;

[0096] The meaning of the output signal of the rotor converter outer loop control model is switched according to the model type, which is the rotor current in the detailed model and the total current in the simplified model;

[0097] The high and low voltage ride-through strategy model performs high and low voltage ride-through simulations by three methods: current limiting, changing the current reference output by the outer loop control of the rotor side converter, or changing the outer loop control power reference value.

[0098] Among them, the specific link models include: wind speed model;

[0099] The wind speed model includes: a gradual wind model, a gust model and a random wind model.

[0100] Among them, the grid-connected interface of the detailed electromechanical transient model includes: stator-side interface and grid-side converter interface;

[0101] Among them, the stator side interface is established through the asynchronous motor stator and rotor voltage equations;

[0102] The current output by the grid-side converter control model is used as a controlled current source to establish a grid-side converter interface.

[0103] Wherein, a controlled current source or a controlled voltage source is used as a grid-connected interface of a simplified electromechanical transient model.

[0104] The method also includes: performing parameter fitting and verification on the established multiple types of electromechanical transient simulation models.

[0105] Among them, parameter fitting and verification are performed on various types of electromechanical transient simulation models, including:

[0106] Through mechanism and simulation tests, the parameters of the electromechanical transient simulation model are classified, key parameters and non-key parameters are determined, the determined key parameters are identified and fitted, and the fitted key parameters are verified through large and small disturbance tests.

[0107] The present invention is further described below in conjunction with specific implementation cases of the present invention:

[0108] Implementation process, such as Figure 2 As shown, including:

[0109] In the first step, according to the various components of the doubly fed unit equipment, the time scale and action frequency band of each link such as wind speed, wind power, pitch angle control, primary frequency modulation, inertia control, shaft system, asynchronous motor, converter, DC capacitor, converter current inner loop control, converter outer loop control, phase-locked loop, high and low voltage ride-through strategy, Chopper protection, Crowbar protection are analyzed to determine the necessary links that meet the time scale of electromechanical transient simulation as the simulation module of electromechanical transient simulation.

[0110] According to the level of detail of the modeling of the converter control system and asynchronous motors, converters, DC capacitors and other links, the simulation requirements in different simulation scenarios are met, including mandatory modules and optional modules, where the mandatory modules include common links and specific links. For links in the range of tens to hundreds of Hz as optional modules, detailed electromechanical transient models must be considered, and simplified electromechanical transient models are not considered. For other low-frequency links as mandatory modules, both detailed electromechanical transient models and simplified electromechanical transient models need to be considered. The model structure is as follows: Figure 3 As shown;

[0111] The second step is to establish a mathematical model suitable for electromechanical transient simulation for each link of the simulation module in step 1, and establish the electrical data and control signal interaction relationship between each simulation module under different types of models including and excluding optional modules according to the coupling relationship of each link. Among them, all parameters are calibrated in terms of local capacity, and the converter current inner loop control, converter outer loop control, phase-locked loop, and asynchronous motor models all use the dq axis coordinate system and a unified coordinate orientation.

[0112] The third step is to establish the grid-connected interface under the xy-axis coordinates of the electromechanical transient simulation model of multi-type doubly-fed wind turbines, realize the joint simulation calculation of the model and the external power grid, perform model initialization and equation solving, and complete the electromechanical transient simulation modeling. Among them, the detailed electromechanical transient model, the simplified electromechanical transient model with voltage source characteristics, and the simplified electromechanical transient model with current source characteristics use different grid-connected interfaces, which can be automatically switched according to the model selection. The result curve of the simulation calculation is as follows: Figure 4 , 5 and 6.

[0113] The fourth step is to fit and verify the parameters of multi-type electromechanical transient simulation models. Through mechanism and simulation test analysis, the simulation model parameters are classified, key parameters and non-key parameters are determined, key parameters are identified, and parameter verification is performed through large and small disturbance tests.

[0114] The optional modules in the first step mainly include the detailed model of asynchronous motor, converter model, DC capacitor, rotor-side converter current inner loop control, phase-locked loop, grid-side converter control, Chopper protection, and Crowbar protection. The common links of the mandatory modules include wind speed, wind power, pitch angle control, primary frequency modulation, inertia control, shaft system, rotor-side converter outer loop control, and high and low voltage ride-through strategies; the specific link is the wind speed model, including gradual wind, gusts, and random wind, which is used in long-term simulation calculations considering wind speed changes. The electromechanical transient simulation model structure includes optional modules and mandatory modules, and the model type used is adaptively selected according to simulation needs.

[0115] In the second step, the detailed model of the asynchronous motor is based on the stator and rotor flux equations and voltage equations, without considering the stator flux change and the turns ratio. The converter model adopts the average value model, with the DC side as a controlled current source and the AC side as a controlled voltage source under the dq axis respectively.

[0116] The inner loop current control of the rotor converter does not consider the voltage cross term, but only considers the rotor current deviation to output the modulation voltage through the proportional integral link. Without considering the modulation link, the modulation voltages Vmd and Vmq output by the inner loop current control are modulated and limited, and the controlled voltage on the AC side of the converter is obtained by using the relationship between the modulation amount and the AC and DC voltage of the converter. Among them, when the Crowbar protection is not started, the controlled voltage value on the AC side of the rotor converter is equal to the rotor voltage of the asynchronous motor.

[0117] The meaning of the output signal of the rotor converter outer loop control can be flexibly set according to the model type. The active control part of the rotor converter outer loop can select speed control, torque control or power control. The output is the rotor current d-axis reference value when the detailed electromechanical transient model is used, and the output is the total current d-axis reference value when the simplified electromechanical transient model is used; the reactive control part can select constant reactive control, constant voltage control or constant power factor control. The output is the rotor current q-axis reference value when the detailed electromechanical model is used, and the output is the total current q-axis reference value when the simplified electromechanical transient model is used.

[0118] The high and low voltage ride-through strategy is implemented through three methods: current limitation, changing the current reference output by the outer loop control of the rotor converter, or changing the power reference of the outer loop control. The methods are flexible and can be selected at will. The grid-side converter control does not consider the current inner loop, but only considers the outer loop DC voltage loop and power loop to control the output grid-side current reference value, ignoring the grid-side converter model.

[0119] The Crowbar protection output signal is used as the enable signal for the rotor side inner loop current control output and the asynchronous motor rotor parameter modification. When the Crowbar protection is put into operation, the rotor side inner loop current control output modulation voltage is set to 0 to simulate the inverter lockout. When the Crowbar protection is put into operation, the asynchronous motor model corrects the rotor resistance related parameters, and the motor rotor resistance is corrected to the electronic rotor resistance plus the Crowbar protection circuit resistance.

[0120] In the third step, the grid-connected interface uses xy axis coordinates, and the detailed electromechanical transient model grid-connected interface is divided into two parts: the stator side and the grid-side converter. The stator side uses the stator and rotor voltage equations of the asynchronous motor to establish a voltage source grid-connected interface, and the grid-side converter part uses a controlled current source to interface with the grid. The voltage source characteristic simplifies the grid-connected interface of the electromechanical transient model using a controlled voltage source, and the internal potential does not change suddenly at the moment of the fault. The current source characteristic simplifies the grid-connected interface of the electromechanical transient model using a controlled current source or a controlled voltage source, and the internal potential of the controlled voltage source can change suddenly. During the joint calculation, the injected current and grid admittance of the grid-connected interface use the system standard.

[0121] The present invention does not require a large number of model parameters to be modified, and different types of simulation models can be flexibly switched only through mode selection.

[0122] For the simulation scenario of access to a low short-circuit ratio weak system, this method adaptively selects a detailed electromechanical transient simulation model of the doubly-fed wind turbine, which is beneficial to improving the accuracy of electromechanical transient simulation.

[0123] For simulation scenarios connected to strong systems, the present invention adaptively selects a doubly-fed wind turbine to simplify the electromechanical transient simulation model, thereby improving the simulation speed while ensuring that the simulation accuracy meets the requirements.

[0124] The simulation method proposed in the present invention takes into account the electromechanical transient simulation framework of large power grids, can be easily applied to mainstream electromechanical transient simulation software, and can improve the analysis capability and application scope of electromechanical transient simulation software.

[0125] Embodiment 2:

[0126] The present invention also proposes an electromechanical transient simulation system 200 for a doubly-fed wind turbine generator system, such as Figure 7 As shown, including:

[0127] The initial unit 201 is used to determine the necessary links of the simulation according to the simulation time scale and action frequency band of the electromechanical transient simulation of the doubly-fed wind turbine generator set, and establish a simulation module based on the necessary links;

[0128] A calculation unit 202, used to establish a mathematical model of the simulation module, and to establish an interactive relationship between electrical data and control signals between the simulation modules based on the coupling relationship between the necessary links;

[0129] The simulation unit 203 is used to establish an electromechanical transient simulation model of the doubly-fed wind turbine generator set based on the mathematical model and the interaction relationship, and perform electromechanical transient simulation on the doubly-fed wind turbine generator set based on the electromechanical transient simulation model.

[0130] Wherein, based on the electromechanical transient simulation model, the electromechanical transient simulation of the doubly-fed wind turbine generator set is performed, including:

[0131] For the electromechanical transient simulation model, different grid-connected interfaces under the xy-axis coordinates are established. By switching the different grid-connected interfaces of the electromechanical transient simulation model, the electromechanical transient simulation model is switched to a detailed electromechanical transient model, a simplified electromechanical transient model with voltage source characteristics, or a simplified electromechanical transient model with current source characteristics. The detailed electromechanical transient model, the simplified electromechanical transient model with voltage source characteristics, or the simplified electromechanical transient model with current source characteristics are initialized and the equation solving steps are performed to perform electromechanical transient simulation on the doubly-fed wind turbine set.

[0132] The initial unit 203 determines the equipment components of the doubly-fed wind turbine generator set that meet the electromechanical time scale, the DC voltage time scale and the current time scale as a necessary part of the simulation.

[0133] Among them, the equipment components include:

[0134] Analyze the wind speed link, wind power link, pitch angle control link, primary frequency regulation link, inertia control link, shaft system link, asynchronous motor link, converter link, DC capacitor link, converter current inner loop control link, converter outer loop control link, phase-locked loop link, high and low voltage ride-through strategy link, Chopper protection link and Crowbar protection link.

[0135] Among them, the simulation module includes: optional modules and mandatory modules;

[0136] Among them, the simulation module established for the necessary links in the frequency range of 50 to 200 Hz is an optional module;

[0137] The optional modules include at least one of the following:

[0138] Asynchronous motor detailed model, converter model, DC capacitor model, rotor-side converter current inner loop control model, phase-locked loop model, grid-side converter control model, Chopper protection model and Crowbar protection model;

[0139] The rotor-side converter current inner loop control model is established based on the rotor current deviation outputting a modulation voltage through a proportional-integral link. After the modulation voltage output by the current inner loop control is modulated and limited, the AC side controlled voltage of the rotor-side converter is determined according to the relationship between the modulation amount and the AC and DC voltages of the rotor-side converter.

[0140] The output signal of the Crowbar protection model is used as an enable signal for the inner loop current control output of the rotor-side converter and the modification of the rotor parameters of the asynchronous motor;

[0141] Among them, the simulation model established for the necessary links in the frequency range of 0.1 to 50 Hz is a mandatory module;

[0142] The required modules include: a general link model and a specific link model.

[0143] The general link model includes at least one of the following: a wind power model, a pitch angle control model, a primary frequency modulation model, an inertia control model, a shaft system model, a rotor-side converter outer loop control model, and a high and low voltage ride-through strategy model;

[0144] The meaning of the output signal of the rotor converter outer loop control model is switched according to the model type, which is the rotor current in the detailed model and the total current in the simplified model;

[0145] The high and low voltage ride-through strategy model performs high and low voltage ride-through simulations by three methods: current limiting, changing the current reference output by the outer loop control of the rotor side converter, or changing the outer loop control power reference value.

[0146] Among them, the specific link models include: wind speed model;

[0147] The wind speed model includes: a gradual wind model, a gust model and a random wind model.

[0148] Among them, the grid-connected interface of the detailed electromechanical transient model includes: stator-side interface and grid-side converter interface;

[0149] Among them, the stator side interface is established through the asynchronous motor stator and rotor voltage equations;

[0150] Among them, a grid-side converter interface is established through a controlled current source and a grid interface.

[0151] Wherein, a controlled current source or a controlled voltage source is used as a grid-connected interface of a simplified electromechanical transient model.

[0152] The simulation unit 203 is also used to perform parameter fitting and verification on the established multiple types of electromechanical transient simulation models.

[0153] The simulation unit 203 performs parameter fitting and verification on the established multiple types of electromechanical transient simulation models, including:

[0154] Through mechanism and simulation tests, the parameters of the electromechanical transient simulation model are classified, key parameters and non-key parameters are determined, the determined key parameters are identified and fitted, and the fitted key parameters are verified through large and small disturbance tests.

[0155] The present invention does not require a large number of model parameters to be modified, and different types of simulation models can be flexibly switched only by selecting a grid-connected interface, and the simulation speed is improved while ensuring that the simulation accuracy meets the requirements.

[0156] Embodiment 3:

[0157] Based on the same inventive concept, the present invention also provides a computer device, which includes a processor and a memory, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute 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 (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding functions, so as to implement the steps of the method in the above embodiment.

[0158] Embodiment 4:

[0159] Based on the same inventive concept, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium here can include both a built-in storage medium in a computer device and an extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. 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 embodiment.

[0160] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may 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 codes. The schemes in the embodiments of the present invention may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0161] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0162] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0163] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0164] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0165] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for electromechanical transient simulation of a doubly-fed wind turbine generator system, characterized in that: include: According to the simulation time scale and action frequency band of the electromechanical transient simulation of the doubly-fed wind turbine generator set, the necessary simulation links are determined, and a simulation module is established based on the necessary links; Establishing a mathematical model of the simulation module, and establishing an interactive relationship between electrical data and control signals between the simulation modules based on the coupling relationship between the necessary links; An electromechanical transient simulation model of a doubly-fed wind turbine generator set is established based on the mathematical model and the interaction relationship, and an electromechanical transient simulation is performed on the doubly-fed wind turbine generator set based on the electromechanical transient simulation model.

2. The electromechanical transient simulation method according to claim 1, characterized in that: The electromechanical transient simulation of the doubly-fed wind turbine generator set based on the electromechanical transient simulation model includes: For the electromechanical transient simulation model, different grid-connected interfaces under the xy-axis coordinates are established. By switching the different grid-connected interfaces of the electromechanical transient simulation model, the electromechanical transient simulation model is switched to a detailed electromechanical transient model, a simplified electromechanical transient model with voltage source characteristics, or a simplified electromechanical transient model with current source characteristics. The detailed electromechanical transient model, the simplified electromechanical transient model with voltage source characteristics, or the simplified electromechanical transient model with current source characteristics are initialized and the equation solving steps are performed to perform electromechanical transient simulation on the doubly-fed wind turbine set.

3. The electromechanical transient simulation method according to claim 1, characterized in that: Determining the equipment components of the doubly-fed wind turbine generator system that meet the electromechanical time scale, DC voltage time scale and current time scale is a necessary step in the simulation.

4. The electromechanical transient simulation method according to claim 3, characterized in that: The components of the equipment include: Analyze the wind speed link, wind power link, pitch angle control link, primary frequency regulation link, inertia control link, shaft system link, asynchronous motor link, converter link, DC capacitor link, converter current inner loop control link, converter outer loop control link, phase-locked loop link, high and low voltage ride-through strategy link, Chopper protection link and Crowbar protection link.

5. The electromechanical transient simulation method according to claim 1, characterized in that: The simulation module includes: an optional module and a mandatory module; Among them, the simulation module established for the necessary links in the frequency range of 50 to 200 Hz is an optional module; The optional modules include at least one of the following: Asynchronous motor detailed model, converter model, DC capacitor model, rotor-side converter current inner loop control model, phase-locked loop model, grid-side converter control model, Chopper protection model and Crowbar protection model; The rotor-side converter current inner loop control model is established based on the rotor current deviation outputting a modulation voltage through a proportional-integral link. After the modulation voltage output by the current inner loop control is modulated and limited, the AC side controlled voltage of the rotor-side converter is determined according to the relationship between the modulation amount and the AC and DC voltages of the rotor-side converter. The output signal of the Crowbar protection model is used as an enable signal for the inner loop current control output of the rotor-side converter and the modification of the rotor parameters of the asynchronous motor; Among them, the simulation model established for the necessary links in the frequency range of 0.1 to 50 Hz is a mandatory module; The required modules include: a general link model and a specific link model.

6. The electromechanical transient simulation method according to claim 5, characterized in that: The general link model includes: wind power model, pitch angle control model, primary frequency modulation model, inertia control model, shaft system model, rotor side converter outer ring control model and high and low voltage ride-through strategy model; The meaning of the output signal of the rotor converter outer loop control model is switched according to the model type, which is the rotor current in the detailed model and the total current in the simplified model; The high and low voltage ride-through strategy model performs high and low voltage ride-through simulations by three methods: current limiting, changing the current reference output by the outer loop control of the rotor-side converter, or changing the outer loop control power reference value.

7. The electromechanical transient simulation method according to claim 5, characterized in that: The specific link model includes: a wind speed model; The wind speed model includes: a gradual wind model, a gust model and a random wind model.

8. The electromechanical transient simulation method according to claim 2, characterized in that: The grid-connected interface of the detailed electromechanical transient model includes: a stator-side interface and a grid-side converter interface; Among them, the stator side interface is established through the asynchronous motor stator and rotor voltage equations; The current output by the grid-side converter control model is used as a controlled current source to establish a grid-side converter interface.

9. The electromechanical transient simulation method according to claim 2, characterized in that: A controlled current source or a controlled voltage source is used as the grid-connected interface of the simplified electromechanical transient model.

10. The electromechanical transient simulation method according to claim 1, characterized in that: The method further comprises: performing parameter fitting and verification on the established multiple types of electromechanical transient simulation models.

11. The electromechanical transient simulation method according to claim 10, characterized in that: The parameter fitting and verification of the established multiple types of electromechanical transient simulation models include: Through mechanism and simulation tests, the parameters of the electromechanical transient simulation model are classified, key parameters and non-key parameters are determined, the determined key parameters are identified and fitted, and the fitted key parameters are verified through large and small disturbance tests.

12. An electromechanical transient simulation system for a doubly-fed wind turbine generator system, characterized in that: include: The initial unit is used to determine the necessary links of the simulation according to the simulation time scale and action frequency band of the electromechanical transient simulation of the doubly-fed wind turbine generator set, and establish a simulation module based on the necessary links; A calculation unit, used to establish a mathematical model of the simulation module, and to establish an interactive relationship between electrical data and control signals between the simulation modules based on the coupling relationship between the necessary links; The simulation unit is used to establish an electromechanical transient simulation model of the doubly-fed wind turbine generator set based on the mathematical model and the interaction relationship, and to perform electromechanical transient simulation on the doubly-fed wind turbine generator set based on the electromechanical transient simulation model.

13. The electromechanical transient simulation system according to claim 12, characterized in that: The electromechanical transient simulation of the doubly-fed wind turbine generator set based on the electromechanical transient simulation model includes: For the electromechanical transient simulation model, different grid-connected interfaces under the xy-axis coordinates are established. By switching the different grid-connected interfaces of the electromechanical transient simulation model, the electromechanical transient simulation model is switched to a detailed electromechanical transient model, a simplified electromechanical transient model with voltage source characteristics, or a simplified electromechanical transient model with current source characteristics. The detailed electromechanical transient model, the simplified electromechanical transient model with voltage source characteristics, or the simplified electromechanical transient model with current source characteristics are initialized and the equation solving steps are performed to perform electromechanical transient simulation on the doubly-fed wind turbine set.

14. The electromechanical transient simulation system according to claim 12, characterized in that: The initial unit determines the equipment components of the doubly-fed wind turbine generator set that meet the electromechanical time scale, the DC voltage time scale and the current time scale as a necessary part of the simulation.

15. The electromechanical transient simulation method according to claim 12, characterized in that: The components of the equipment include: Analyze the wind speed link, wind power link, pitch angle control link, primary frequency regulation link, inertia control link, shaft system link, asynchronous motor link, converter link, DC capacitor link, converter current inner loop control link, converter outer loop control link, phase-locked loop link, high and low voltage ride-through strategy link, Chopper protection link and Crowbar protection link.

16. The electromechanical transient simulation system according to claim 12, characterized in that: The simulation module includes: an optional module and a mandatory module; Among them, the simulation module established for the necessary links in the frequency range of 50 to 200 Hz is an optional module; The optional modules include at least one of the following: Asynchronous motor detailed model, converter model, DC capacitor model, rotor-side converter current inner loop control model, phase-locked loop model, grid-side converter control model, Chopper protection model and Crowbar protection model; The rotor-side converter current inner loop control model is established based on the rotor current deviation outputting a modulation voltage through a proportional-integral link. After the modulation voltage output by the current inner loop control is modulated and limited, the AC side controlled voltage of the rotor-side converter is determined according to the relationship between the modulation amount and the AC and DC voltages of the rotor-side converter. The output signal of the Crowbar protection model is used as an enable signal for the inner loop current control output of the rotor-side converter and the modification of the rotor parameters of the asynchronous motor; Among them, the simulation model established for the necessary links in the frequency range of 0.1 to 50 Hz is a mandatory module; The required modules include: a general link model and a specific link model.

17. The electromechanical transient simulation system according to claim 16, characterized in that: The general link model includes at least one of the following: a wind power model, a pitch angle control model, a primary frequency modulation model, an inertia control model, a shaft system model, a rotor-side converter outer ring control model, and a high and low voltage ride-through strategy model; The meaning of the output signal of the rotor converter outer loop control model is switched according to the model type, which is the rotor current in the detailed model and the total current in the simplified model; The high and low voltage ride-through strategy model performs high and low voltage ride-through simulations by three methods: current limiting, changing the current reference output by the outer loop control of the rotor-side converter, or changing the outer loop control power reference value.

18. The electromechanical transient simulation system according to claim 16, characterized in that: The specific link model includes: a wind speed model; The wind speed model includes: a gradual wind model, a gust model and a random wind model.

19. The electromechanical transient simulation system according to claim 13, characterized in that: The grid-connected interface of the detailed electromechanical transient model includes: a stator-side interface and a grid-side converter interface; Among them, the stator side interface is established through the asynchronous motor stator and rotor voltage equations; Among them, a grid-side converter interface is established through a controlled current source and a grid interface.

20. The electromechanical transient simulation system according to claim 13, characterized in that: A controlled current source or a controlled voltage source is used as the grid-connected interface of the simplified electromechanical transient model.

21. The electromechanical transient simulation system according to claim 12, characterized in that: The simulation unit is also used to perform parameter fitting and verification on established multiple types of electromechanical transient simulation models.

22. The electromechanical transient simulation system according to claim 21, characterized in that: The simulation unit performs parameter fitting and verification on the established multiple types of electromechanical transient simulation models, including: Through mechanism and simulation tests, the parameters of the electromechanical transient simulation model are classified, key parameters and non-key parameters are determined, the determined key parameters are identified and fitted, and the fitted key parameters are verified through large and small disturbance tests.

23. A computer device, characterized in that: include: one or more processors; a processor for executing one or more programs; When the one or more programs are executed by the one or more processors, the method according to any one of claims 1 to 11 is implemented.

24. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed, the method according to any one of claims 1 to 11 is implemented.

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