Doubly-fed wind generator reactive power control method and device considering phase-lock transient coupling response, storage medium and computer equipment

Abstract

The application discloses a kind of double-fed wind turbine reactive power control method, device, storage medium and computer equipment considering phase-locked transient coupling response, the method includes: when detecting the voltage amplitude of the grid connection point of double-fed wind turbine is lower than fault threshold, the voltage phase angle of the grid connection point of double-fed wind turbine before fault, the voltage phase angle mutation of the grid connection point before and after fault, and the voltage amplitude of the grid connection point after fault are acquired, the phase-locked deviation of double-fed wind turbine is calculated;According to the voltage amplitude of the grid connection point after fault and phase-locked deviation, the reactive error term of double-fed wind turbine, active coupling term and stator flux linkage coupling term are calculated;According to reactive error term, active coupling term and stator flux linkage coupling term, the reactive power control instruction value of double-fed wind turbine is calculated;The reactive control reference value of double-fed wind turbine is modified as reactive power control instruction value, to implement reactive control.

Description

Technical Field

[0001] This application relates to the field of power system protection and control technology, and in particular to a reactive power control method, device, storage medium and computer equipment for doubly-fed wind turbine generators that takes into account phase-locked transient coupling response. Background Technology

[0002] The reactive power control of existing doubly-fed induction generator (DFIG) wind turbines mainly focuses on the following three aspects: 1) Optimizing control parameters, i.e., by introducing proportional coefficients and PI controllers for optimization. This method is simple in principle and easy to implement, requiring no modification to the converter control structure, but it is limited by the control capability of the converter. 2) Adding hardware equipment, including configuring supercapacitor energy storage and chemical batteries, but this method increases hardware costs and changes the main circuit topology of the wind turbine. 3) Coordinating the wind turbine with energy storage equipment, etc., by coordinating the control capabilities of the DFIG wind turbine with supercapacitors, flywheels, and other energy storage equipment, thereby providing reactive power support for the system.

[0003] However, existing control methods still face the following problems: 1) Optimizing control parameters is mostly determined based on the unit's control capability or system power demand, making it difficult to simultaneously consider equipment safety and system reactive power requirements. Furthermore, the tuning of control parameters does not take into account the coupling effect of the phase-locked loop under fault conditions, and after adjusting the control parameters, it is necessary to verify whether the wind turbine meets the small-disturbance instability limit. 2) Coordinating energy storage and other equipment is limited by equipment cost. In addition, further research is needed on the control parameter tuning and control capability allocation between wind turbines and energy storage equipment. Summary of the Invention

[0004] In view of this, embodiments of this application provide a method, apparatus, storage medium, and computer equipment for reactive power control of a doubly-fed wind turbine generator that takes into account phase-locked transient coupling response.

[0005] According to one aspect of this application, a reactive power control method for a doubly-fed induction generator (DFIG) wind turbine considering phase-locked transient coupling response is provided, the method comprising: When the grid connection voltage amplitude of the doubly fed wind turbine is detected to be lower than the fault threshold, the phase angle of the grid connection voltage before the fault, the sudden change in the phase angle of the grid connection voltage before and after the fault, and the voltage amplitude of the grid connection voltage after the fault are obtained, and the phase-locking deviation of the doubly fed wind turbine is calculated. Based on the voltage amplitude at the grid connection point after the fault and the phase-locking deviation, calculate the reactive power error term, active power coupling term, and stator flux coupling term of the doubly fed wind turbine; Based on the reactive power error term, the active power coupling term, and the stator flux coupling term, calculate the reactive power control command value of the doubly fed wind turbine generator; The reactive power control reference value of the doubly fed wind turbine is modified to the reactive power control command value to implement reactive power control.

[0006] According to another aspect of this application, a reactive power control device for a doubly-fed wind turbine generator considering phase-locked transient coupling response is provided, the device comprising: The fault detection module is used to obtain the phase angle of the grid connection voltage of the doubly fed wind turbine before the fault, the sudden change in the phase angle of the grid connection voltage before and after the fault, and the voltage amplitude of the grid connection voltage after the fault when the grid connection voltage amplitude of the doubly fed wind turbine is detected to be lower than the fault threshold, and to calculate the phase-locked deviation of the doubly fed wind turbine. The error calculation module is used to calculate the reactive power error term, active power coupling term, and stator flux coupling term of the doubly fed wind turbine based on the voltage amplitude at the grid connection point after the fault and the phase-locked deviation. The instruction calculation module is used to calculate the reactive power control instruction value of the doubly-fed wind turbine based on the reactive power error term, the active power coupling term, and the stator flux coupling term. The reactive power control module is used to modify the reactive power control reference value of the doubly fed wind turbine to the reactive power control command value in order to implement reactive power control.

[0007] According to another aspect of this application, a storage medium is provided that stores a computer program thereon, which, when executed by a processor, implements the above-described reactive power control method for a doubly-fed wind turbine generator taking into account phase-locked transient coupling response.

[0008] According to another aspect of this application, a computer device is provided, including a storage medium, a processor, and a computer program stored on the storage medium and executable on the processor, wherein the processor executes the program to implement the above-described reactive power control method for a doubly-fed wind turbine generator taking into account phase-locked transient coupling response.

[0009] By utilizing the above technical solutions, the reactive power control method, device, storage medium, and computer equipment for doubly-fed induction generator (DFIG) wind turbines, which takes into account phase-locked transient coupling response, provided in this application has the following advantages: 1) The control structure is simple, requiring no additional feedback loops, and only the introduction of compensation terms into the reactive power control loop of the DFIG wind turbine, making it easy to implement theoretically and apply in engineering; 2) It improves the control accuracy of the DFIG wind turbine by introducing compensation terms into the reactive power control loop, thereby eliminating the coupling effect between active power and stator flux caused by phase-locked transient coupling response under grid faults; 3) It increases the grid connection voltage of the wind turbine after grid faults by introducing compensation terms into the reactive power control loop of the DFIG wind turbine, thereby improving the voltage support capability of the wind turbine and providing guidance for the research and development of power control devices for DFIG wind turbines.

[0010] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0011] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 A flowchart illustrating a reactive power control method for a doubly-fed wind turbine generator considering phase-locked transient coupling response, provided in an embodiment of this application, is shown. Figure 2 This illustration shows a control logic diagram of a doubly-fed wind turbine reactive power control method considering phase-locked transient coupling response, provided in an embodiment of this application. Figure 3 This illustration shows a structural schematic diagram of a doubly-fed wind turbine reactive power control device that takes into account phase-locked transient coupling response, according to an embodiment of this application. Figure 4 A schematic diagram of the device structure of a computer device provided in an embodiment of this application is shown. Detailed Implementation

[0012] The present application will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present application can be combined with each other.

[0013] This embodiment provides a reactive power control method for doubly-fed wind turbines that takes into account phase-locked transient coupling response, such as... Figure 1 As shown, the method includes: Step 101: When the grid connection point voltage amplitude of the doubly-fed wind turbine is detected to be lower than the fault threshold, obtain the grid connection point voltage phase angle before the fault, the sudden change in grid connection point voltage phase angle before and after the fault, and the grid connection point voltage amplitude after the fault, and calculate the phase-locked deviation of the doubly-fed wind turbine.

[0014] Among them, the grid connection point voltage amplitude refers to the effective voltage value at the connection point between the doubly-fed induction generator (DFIG) and the power grid. This parameter can be collected in real time through a voltage transformer, and its characteristics directly affect whether the generator can accurately perceive the grid's operating status. The fault threshold refers to a pre-set voltage amplitude judgment threshold used to distinguish between normal operation and fault conditions. The phase-locked loop (PLL) deviation refers to the phase difference between the PLL output angle and the actual grid voltage vector angle. This deviation is generated by the combined excitation of voltage amplitude drop and phase jump at the moment of fault, and its dynamic evolution process determines the accuracy of subsequent compensation terms.

[0015] Specifically, the grid-connected voltage signal collected by the voltage transformer is first converted from analog to digital and then sent to the comparison unit of the digital signal processor. This comparison unit has a built-in fault threshold register for real-time comparison of the voltage amplitude with the fault threshold. When the voltage amplitude is detected to be lower than the fault threshold, the phase-locked loop (PLL) deviation calculation task is triggered. For example, the calculation of the PLL deviation of the doubly-fed wind turbine includes: determining the natural oscillation angular frequency based on the integral coefficient of the PI controller of the PLL and the grid-connected voltage amplitude after the fault; determining the damping ratio based on the natural oscillation angular frequency, the proportional coefficient and integral coefficient of the PI controller of the PLL; determining the damped oscillation frequency based on the natural oscillation angular frequency and the damping ratio; and calculating the PLL deviation of the doubly-fed wind turbine based on the grid-connected voltage phase angle before the fault, the sudden change in the grid-connected voltage phase angle, the damping ratio, the natural oscillation angular frequency, and the damped oscillation frequency.

[0016] The specific formula for calculating phase-locked loop error is as follows:

[0017] In the formula, The phase angle of the grid connection point voltage before the fault; This refers to the sudden change in the phase angle of the grid connection point voltage caused by the fault. This represents the voltage amplitude at the grid connection point after the fault. and These are the proportional and integral coefficients of the PI controller in a phase-locked loop (PLL). The natural oscillation angular frequency refers to the inherent frequency of the phase error dynamic response of the phase-locked loop under fault excitation; The damping ratio is a dimensionless coefficient that characterizes the oscillation decay rate of the phase error of the phase-locked loop. It is determined by the phase-locked loop proportional coefficient, integral coefficient and natural oscillation angular frequency. This coefficient determines whether the response curve exhibits an underdamped, critically damped or overdamped shape. The damped oscillation frequency refers to the actual angular frequency of the phase error oscillation in the underdamped state of the phase-locked loop. This frequency is the actual oscillation beat under the combined effect of the natural oscillation angular frequency and the damping ratio. Phase-locked loop (PLL) deviation refers to the time-varying difference between the output angle of the PLL and the actual phase of the grid voltage. This difference evolves in the form of damped oscillations during the fault transient process and is determined by the initial phase jump amplitude and the second-order dynamic characteristics of the system.

[0018] Step 102: Based on the voltage amplitude at the grid connection point after the fault and the phase-locked loop deviation, calculate the reactive power error term, active power coupling term, and stator flux coupling term of the doubly-fed wind turbine.

[0019] Among them, the reactive power error term refers to the reactive power deviation component caused by the deviation of the grid connection point voltage amplitude from the rated value. Its physical meaning is that the voltage amplitude drop directly leads to a deviation between the stator-side reactive power output and the reference value, and this deviation needs to be compensated in the control commands. The active power coupling term refers to the coupling effect of the active current component in the reactive power control channel caused by phase-locked loop deviation. The stator flux linkage coupling term refers to the coupling effect of the transient component of the stator flux linkage caused by sudden changes in voltage amplitude and phase during fault transients on reactive power. This term reflects the additional effect of the stator flux linkage dynamic changes on reactive power.

[0020] In this embodiment, the phase-locked error and the real-time acquired voltage amplitude at the grid connection point after the fault are respectively sent to three parallel calculation channels. The three channels correspond to the calculation of reactive power error, active power coupling, and stator flux coupling, respectively.

[0021] In an optional embodiment, calculating the reactive power error term of the doubly-fed wind turbine includes: calculating the coupling gain factor based on the voltage amplitude at the grid connection point after the fault, the stator inductance, the magnetizing inductance, the proportional coefficient of the PI controller in the outer loop of the RSC control, and the phase-locked loop deviation; and calculating the reactive power error term of the doubly-fed wind turbine based on the coupling gain factor and the reactive power reference value.

[0022] The coupling gain factor is a dynamic adjustment coefficient used to characterize the impact of phase-locked loop deviation on the power control loop of a doubly-fed induction generator (DFIG) wind turbine. This coefficient is jointly determined by the post-fault grid connection point voltage amplitude, stator inductance, magnetizing inductance, the proportional coefficient of the proportional-integral (PI) regulator in the rotor-side converter (RSC) control outer loop, and the phase-locked loop deviation. Its special performance lies in its ability to adaptively change with the voltage drop depth and phase jump degree, making it suitable for real-time adjustment of reactive power compensation intensity during fault transients. The stator inductance refers to the self-inductance coefficient of the stator winding itself, and its physical value is determined by the stator slot type, number of turns, and core magnetic circuit length. The magnetizing inductance refers to the mutual inductance coefficient between the stator and rotor windings, reflecting the strength of magnetic coupling between them. The PI controller in the RSC control outer loop refers to the proportional-integral adjustment unit in the power outer loop control circuit of the DFIG wind turbine rotor-side converter. This unit contains two core parameters: proportional coefficient and integral coefficient. It achieves independent control of active and reactive power by adjusting the d-axis and q-axis components of the rotor current.

[0023] Specifically, the reactive power error term of a doubly-fed wind turbine is calculated using the following method:

[0024] In the formula, This is a reference value for reactive power. Coupling gain factor. satisfy:

[0025] In the formula, , These are the stator inductance and the magnetizing inductance, respectively. This is the proportional coefficient of the PI controller in the outer loop of the RSC control.

[0026] In an optional embodiment, calculating the active power coupling term of the doubly-fed wind turbine includes: calculating the active power coupling term of the doubly-fed wind turbine based on the voltage amplitude at the grid connection point after the fault, the stator inductance, the magnetizing inductance, the proportional coefficient of the PI controller in the outer loop of the RSC control, the phase-locked loop deviation, the coupling gain factor, and the stator active power reference value.

[0027] Among them, the stator active power reference value refers to the set target value of the active power control channel in the power outer loop control of the doubly fed wind turbine generator. This value is given by the maximum power point tracking algorithm or the upper-level scheduling command during steady-state operation. During fault transients, it usually remains unchanged or decreases at a certain slope.

[0028] Specifically, the active power coupling term of a doubly-fed wind turbine is calculated using the following method:

[0029] In the formula, This is a reference value for stator active power.

[0030] In an optional embodiment, calculating the stator flux coupling term of the doubly-fed wind turbine includes: calculating the stator flux coupling term of the doubly-fed wind turbine based on the voltage amplitude at the grid connection point after the fault, the stator inductance, the excitation inductance, the proportional coefficient of the PI controller in the outer loop of the RSC control, the phase-locked loop deviation, the coupling gain factor, and the synchronous angular velocity.

[0031] Among them, the synchronous angular velocity refers to the rotational angular frequency of the stator voltage vector when the doubly fed wind turbine is connected to the grid. This angular velocity corresponds to the fundamental frequency of the power grid (314 rad / s under standard power frequency). Its value is determined by the power grid frequency and can be regarded as a constant value or output in real time by the phase-locked loop during fault transient process.

[0032] Specifically, the stator flux coupling term of the doubly-fed wind turbine is calculated using the following method:

[0033] In the formula, This refers to the synchronous angular velocity.

[0034] By performing parameterized calculations on the reactive power error term, active power coupling term, and stator flux coupling term using the three optional implementation methods described above, all three coupling components can be updated collaboratively based on a unified coupling gain factor and phase-locked loop deviation. Each calculation channel can operate independently and in parallel, and other channels can still function normally when any channel malfunctions, effectively improving the fault tolerance and computational flexibility of the control system.

[0035] Step 103: Calculate the reactive power control command value of the doubly-fed wind turbine based on the reactive power error term, the active power coupling term, and the stator flux coupling term.

[0036] Among them, the reactive power control command value refers to the corrected control target value used to replace the original reactive power reference value. This command value integrates the effects of reactive power error term, active power coupling term and stator flux coupling term, and can provide an accurate reactive power control target under phase-locked transient coupling conditions.

[0037] In an optional embodiment, calculating the reactive power control command value of the doubly-fed induction generator (DFIG) wind turbine based on the reactive power error term, the active power coupling term, and the stator flux coupling term includes: calculating the reactive power control command value of the DFIG wind turbine based on the reactive power error term, the active power coupling term, the stator flux coupling term, the coupling gain factor, and the reactive power reference value. Figure 2 As shown, specifically, the control command proportional coefficient is determined based on the reactive power error term and the coupling gain factor, the sum of the active power coupling term and the stator flux coupling term is calculated, the basic control command value is determined based on the difference between the reactive power reference value and the sum, and the reactive power control command value of the doubly-fed wind turbine is determined based on the product of the control command proportional coefficient and the basic control command value.

[0038] In this embodiment, the control command proportional coefficient refers to the scaling factor used to scale the amplitude of the basic control command value. The basic control command value refers to the intermediate control reference value obtained by subtracting the disturbances of active power coupling and stator flux coupling from the reactive power reference value before applying proportional scaling. This reference value reflects the ideal reactive power compensation base requirement after eliminating the effects of active power coupling and flux transients.

[0039] Specifically, the reactive power control command value of the doubly-fed wind turbine generator is calculated as follows: .

[0040] Step 104: Modify the reactive power control reference value of the doubly fed wind turbine to the reactive power control command value to implement reactive power control.

[0041] Among them, the reactive power control reference value refers to the original target value set by the reactive power control loop of the rotor-side converter of the doubly fed wind turbine. This value is issued by the upper-level dispatching system or the wind farm-level controller during steady-state operation, and needs to be replaced by the corrected command value in fault conditions.

[0042] In this embodiment, the reactive power control command value is written into the reactive power control reference value register of the rotor-side converter controller of the doubly-fed induction generator (DFIG) wind turbine. This register is a dedicated storage unit in the controller for storing the reactive power control target value. The writing operation is completed through the controller's internal value update mechanism. Specifically, at the beginning of each control cycle, the controller reads the current value of the reactive power control reference value register as the target value for control in this cycle. After the calculation of the new command value is completed, the controller writes the new command value into the register at the beginning of the next control cycle, replacing the original reactive power control reference value. After the register is updated, the reactive power control loop of the rotor-side converter uses the updated command value as the control target, and drives the q-axis component of the rotor current to track the target value through the proportional-integral regulator, thereby realizing closed-loop control of reactive power.

[0043] By applying the technical solution of this embodiment, the tracking error of the phase-locked loop (PLL) during grid fault transients can be accurately quantified through the acquisition and calculation of the PLL deviation. Through separate calculations of reactive power error, active power coupling, and stator flux coupling, the various sources of influence of the PLL transient coupling response on reactive power control can be described separately and uniformly incorporated into the control command. By generating reactive power control command values ​​and dynamically replacing reactive power control reference values, the doubly-fed induction generator (DFIG) wind turbine can implement adaptive reactive power control under grid connection point voltage dips and phase jumps. Overall, this method effectively improves the active-reactive power coupling problem caused by PLL transient tracking deviation, enhancing the reactive power response capability and voltage support effect of the DFIG wind turbine during grid fault transients.

[0044] The advantages of the above-mentioned reactive power control method for doubly-fed induction generator (DFIG) wind turbines, which takes into account phase-locked transient coupling response, are as follows: 1) The control structure is simple, requiring no additional feedback loops, and only a compensation term needs to be introduced into the reactive power control loop of the DFIG wind turbine, making it easy to implement theoretically and apply in engineering; 2) It improves the control accuracy of the DFIG wind turbine by introducing a compensation term into the reactive power control loop, thereby eliminating the coupling effect between active power and stator flux caused by phase-locked transient coupling response under grid faults; 3) It increases the grid connection voltage of the wind turbine after grid faults by introducing a compensation term into the reactive power control loop of the DFIG wind turbine, thereby improving the voltage support capability of the wind turbine and providing guidance for the research and development of power control devices for DFIG wind turbines.

[0045] Furthermore, as Figure 1In its specific implementation, this application provides a reactive power control device for a doubly-fed wind turbine that takes into account the phase-locked transient coupling response, such as... Figure 3 As shown, the device includes: The fault detection module is used to obtain the phase angle of the grid connection voltage of the doubly fed wind turbine before the fault, the sudden change in the phase angle of the grid connection voltage before and after the fault, and the voltage amplitude of the grid connection voltage after the fault when the grid connection voltage amplitude of the doubly fed wind turbine is detected to be lower than the fault threshold, and to calculate the phase-locked deviation of the doubly fed wind turbine. The error calculation module is used to calculate the reactive power error term, active power coupling term, and stator flux coupling term of the doubly fed wind turbine based on the voltage amplitude at the grid connection point after the fault and the phase-locked deviation. The instruction calculation module is used to calculate the reactive power control instruction value of the doubly-fed wind turbine based on the reactive power error term, the active power coupling term, and the stator flux coupling term. The reactive power control module is used to modify the reactive power control reference value of the doubly fed wind turbine to the reactive power control command value in order to implement reactive power control.

[0046] In an optional embodiment, the fault detection module is specifically used for: The natural oscillation angular frequency is determined based on the integral coefficient of the PI controller of the phase-locked loop and the voltage amplitude at the grid connection point after the fault; the damping ratio is determined based on the natural oscillation angular frequency, the proportional coefficient and the integral coefficient of the PI controller of the phase-locked loop; and the damped oscillation frequency is determined based on the natural oscillation angular frequency and the damping ratio. The phase-locked error of the doubly-fed wind turbine is calculated based on the phase angle of the grid connection point voltage before the fault, the sudden change in the phase angle of the grid connection point voltage, the damping ratio, the natural oscillation angular frequency, and the damped oscillation frequency.

[0047] In an optional embodiment, the error calculation module is specifically used for: Calculate the coupling gain factor based on the voltage amplitude at the grid connection point after the fault, the stator inductance, the magnetizing inductance, the proportional coefficient of the PI controller in the outer loop of the RSC control, and the phase-locked loop deviation. The reactive power error term of the doubly-fed wind turbine is calculated based on the coupling gain factor and the reactive power reference value.

[0048] In an optional embodiment, the error calculation module is specifically used for: The active coupling term of the doubly-fed wind turbine is calculated based on the voltage amplitude at the grid connection point after the fault, the stator inductance, the excitation inductance, the proportional coefficient of the PI controller in the outer loop of the RSC control, the phase-locked deviation, the coupling gain factor, and the stator active power reference value.

[0049] In an optional embodiment, the error calculation module is specifically used for: Based on the voltage amplitude at the grid connection point after the fault, stator inductance, magnetizing inductance, proportional coefficient of the PI controller in the outer loop of RSC control, phase-locked loop deviation, coupling gain factor, and synchronous angular velocity, calculate the stator flux coupling term of the doubly-fed wind turbine.

[0050] In an optional embodiment, the instruction calculation module is specifically used for: The reactive power control command value of the doubly-fed wind turbine is calculated based on the reactive power error term, the active power coupling term, the stator flux coupling term, the coupling gain factor, and the reactive power reference value.

[0051] In an optional embodiment, the instruction calculation module is specifically used for: The control command proportional coefficient is determined based on the reactive power error term and the coupling gain factor. The sum of the active power coupling term and the stator flux coupling term is calculated. The basic control command value is determined based on the difference between the reactive power reference value and the sum. The reactive power control command value of the doubly-fed wind turbine is determined based on the product of the control command proportional coefficient and the basic control command value.

[0052] It should be noted that other corresponding descriptions of the functional units involved in the reactive power control device for a doubly-fed wind turbine generator that takes into account phase-locked transient coupling response provided in the embodiments of this application can be found in the following references. Figures 1 to 2 The corresponding descriptions in the method will not be repeated here.

[0053] This application also provides a computer device, which may specifically be a personal computer, a server, a network device, etc. Figure 4 As shown, the computer device includes a bus, a processor, memory, and a communication interface, and may also include an input / output interface and a display device. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The database stores location information. The network interface allows communication with external terminals via a network connection. When the computer program is executed by the processor, it implements the steps in the various method embodiments.

[0054] Those skilled in the art will understand that Figure 4The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0055] In one embodiment, a computer-readable storage medium is provided, which may be non-volatile or volatile, having stored thereon a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0056] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0057] It should be noted that the user personal information involved in the embodiments of this application is all authorized (with the knowledge and consent) by the relevant parties or fully authorized by all parties, and the executing entity can obtain it through various legal and compliant means. The collection, storage, use, processing, transmission, provision, and disclosure of the information, data, and signals involved all comply with the relevant laws and regulations of the relevant countries and regions, and do not violate public order and good morals. It should be noted that if any software tools or components other than those of this company appear in the embodiments of this application, they are merely illustrative examples and do not represent actual use.

[0058] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, graphics processors, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0059] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A reactive power control method for a doubly-fed induction generator (DFIG) wind turbine considering phase-locked loop transient coupling response, characterized in that, The method includes: When the grid connection voltage amplitude of the doubly fed wind turbine is detected to be lower than the fault threshold, the phase angle of the grid connection voltage before the fault, the sudden change in the phase angle of the grid connection voltage before and after the fault, and the voltage amplitude of the grid connection voltage after the fault are obtained, and the phase-locking deviation of the doubly fed wind turbine is calculated. Based on the voltage amplitude at the grid connection point after the fault and the phase-locking deviation, calculate the reactive power error term, active power coupling term, and stator flux coupling term of the doubly fed wind turbine; Based on the reactive power error term, the active power coupling term, and the stator flux coupling term, calculate the reactive power control command value of the doubly fed wind turbine generator; The reactive power control reference value of the doubly fed wind turbine is modified to the reactive power control command value to implement reactive power control.

2. The method according to claim 1, characterized in that, The calculation of the phase-locked error of the doubly-fed wind turbine includes: The natural oscillation angular frequency is determined based on the integral coefficient of the PI controller of the phase-locked loop and the voltage amplitude at the grid connection point after the fault; the damping ratio is determined based on the natural oscillation angular frequency, the proportional coefficient and the integral coefficient of the PI controller of the phase-locked loop; and the damped oscillation frequency is determined based on the natural oscillation angular frequency and the damping ratio. The phase-locked error of the doubly-fed wind turbine is calculated based on the phase angle of the grid connection point voltage before the fault, the sudden change in the phase angle of the grid connection point voltage, the damping ratio, the natural oscillation angular frequency, and the damped oscillation frequency.

3. The method according to claim 2, characterized in that, The calculation of the reactive power error term of the doubly-fed wind turbine includes: Calculate the coupling gain factor based on the voltage amplitude at the grid connection point after the fault, the stator inductance, the magnetizing inductance, the proportional coefficient of the PI controller in the outer loop of the RSC control, and the phase-locked loop deviation. The reactive power error term of the doubly-fed wind turbine is calculated based on the coupling gain factor and the reactive power reference value.

4. The method according to claim 3, characterized in that, The calculation of the active power coupling terms of the doubly-fed wind turbine includes: The active coupling term of the doubly-fed wind turbine is calculated based on the voltage amplitude at the grid connection point after the fault, the stator inductance, the excitation inductance, the proportional coefficient of the PI controller in the outer loop of the RSC control, the phase-locked deviation, the coupling gain factor, and the stator active power reference value.

5. The method according to claim 4, characterized in that, The calculation of the stator flux coupling term of the doubly-fed wind turbine includes: Based on the voltage amplitude at the grid connection point after the fault, stator inductance, magnetizing inductance, proportional coefficient of the PI controller in the outer loop of RSC control, phase-locked loop deviation, coupling gain factor, and synchronous angular velocity, calculate the stator flux coupling term of the doubly-fed wind turbine.

6. The method according to claim 5, characterized in that, Based on the reactive power error term, the active power coupling term, and the stator flux coupling term, the reactive power control command value of the doubly-fed wind turbine is calculated, including: The reactive power control command value of the doubly-fed wind turbine is calculated based on the reactive power error term, the active power coupling term, the stator flux coupling term, the coupling gain factor, and the reactive power reference value.

7. The method according to claim 6, characterized in that, Based on the reactive power error term, the active power coupling term, the stator flux coupling term, the coupling gain factor, and the reactive power reference value, the reactive power control command value of the doubly-fed wind turbine is calculated, including: The control command proportional coefficient is determined based on the reactive power error term and the coupling gain factor. The sum of the active power coupling term and the stator flux coupling term is calculated. The basic control command value is determined based on the difference between the reactive power reference value and the sum. The reactive power control command value of the doubly-fed wind turbine is determined based on the product of the control command proportional coefficient and the basic control command value.

8. A reactive power control device for a doubly-fed wind turbine generator considering phase-locked transient coupling response, characterized in that, The device includes: The fault detection module is used to obtain the phase angle of the grid connection voltage of the doubly fed wind turbine before the fault, the sudden change in the phase angle of the grid connection voltage before and after the fault, and the voltage amplitude of the grid connection voltage after the fault when the grid connection voltage amplitude of the doubly fed wind turbine is detected to be lower than the fault threshold, and to calculate the phase-locked deviation of the doubly fed wind turbine. The error calculation module is used to calculate the reactive power error term, active power coupling term, and stator flux coupling term of the doubly fed wind turbine based on the voltage amplitude at the grid connection point after the fault and the phase-locked deviation. The instruction calculation module is used to calculate the reactive power control instruction value of the doubly-fed wind turbine based on the reactive power error term, the active power coupling term, and the stator flux coupling term. The reactive power control module is used to modify the reactive power control reference value of the doubly fed wind turbine to the reactive power control command value in order to implement reactive power control.

9. A storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method of any one of claims 1 to 7.

10. A computer device, comprising a storage medium, a processor, and a computer program stored on the storage medium and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method of any one of claims 1 to 7.

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