Control method of network-forming doubly-fed wind turbine generator, electronic equipment and medium

Abstract

The invention discloses a control method of a network-forming double-fed wind turbine generator, electronic equipment and a medium, and is applied to the field of wind power generation. The method comprises the following steps: determining an additional stator angular frequency based on a proportional-integral controller according to an external system voltage phase angle and a stator phase angle; based on an active power control loop, determining an adjusted stator angular frequency and a stator phase angle according to the stator output active power, the stator output active power reference value, the stator angular frequency reference value and the additional stator angular frequency; determining a first control component and a second control component corresponding to virtual impedance control according to the stator three-phase current and the stator three-phase voltage; determining rotor three-phase voltage corresponding to the rotor three-phase current, the first control component and the second control component based on the voltage control loop; and determining the output voltage of the doubly-fed wind generator according to the adjusted stator phase angle and rotor three-phase voltage. Therefore, stable operation of the multiple doubly-fed wind turbine generators in the network-forming doubly-fed wind turbine generator is realized.

Description

Technical Field

[0001] The present application relates to the field of wind power generation, and in particular to a control method, electronic equipment and medium for a grid-type doubly-fed wind turbine generator set. Background Art

[0002] The reserves of wind energy resources in deep sea areas are much higher than those in the near sea, and the development restrictive factors are small, which facilitates the construction of large-scale offshore wind farms. As the development of offshore wind power resources approaches saturation, the development of deep sea wind power will become an important direction for future development. At present, high-voltage AC transmission and flexible DC transmission in high-voltage DC transmission are usually used to realize the transmission of offshore wind power. At the same time, diode uncontrolled rectifier units (DRU) are also gradually used. DRU is essentially a grid-commutated converter, which requires the connected AC system to provide a stable commutation voltage, and then the various bridge arms in the unit are turned on in sequence to rectify the input side AC voltage into the output side DC voltage. Among them, due to the low loss of the DRU transmission system, small space and weight, simple control, and high economy, it has a good development prospect in the medium and long-distance offshore wind power DC transmission scheme.

[0003] Since the diode uncontrolled rectifier unit has the characteristic of unidirectional power conduction and requires the AC side system to provide a stable voltage, the traditional grid-type wind turbine cannot meet the operation requirements. The reason is that after the grid-type double-fed wind turbine establishes the grid voltage and frequency, if there is a large phase angle error in the three-phase AC voltage when the subsequent wind turbine is connected to the grid, a large impact current will be caused due to the phase angle jump, so it is impossible to provide a stable voltage for the AC side of the diode uncontrolled rectifier unit. In addition, when there are multiple wind turbines on a collector line using a grid-type control strategy, the system may experience power circulation and oscillation, and the system cannot maintain stable operation.

[0004] In view of the above-mentioned technologies, seeking a control method for a grid-type doubly-fed wind turbine generator system is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0005] The purpose of the present application is to provide a control method, electronic device and medium for a grid-type doubly-fed wind turbine generator set, which can solve the problem that power circulation and oscillation may occur in the system of a traditional grid-type wind turbine generator set, thereby failing to maintain stable operation of the system.

[0006] In order to solve the above technical problems, on the one hand, the present application provides a control method for a grid-type doubly-fed wind turbine generator set, which is applied to a single doubly-fed wind turbine generator set, comprising:

[0007] Determining an additional stator angular frequency according to an external system voltage phase angle and a stator phase angle based on a proportional-integral controller;

[0008] Based on the active power control loop, the adjusted stator angular frequency and the stator phase angle are determined according to the stator output active power, the stator output active power reference value, the stator angular frequency reference value and the additional stator angular frequency; wherein the adjusted stator phase angle is the same as the external system voltage phase angle;

[0009] Determine a first control component and a second control component corresponding to the virtual impedance control according to the stator three-phase current and the stator three-phase voltage;

[0010] Determine the rotor three-phase current, the first control component and the rotor three-phase voltage corresponding to the second control component based on the voltage control loop;

[0011] The output voltage of the doubly-fed wind generator is determined according to the adjusted stator phase angle and the rotor three-phase voltage.

[0012] Preferably, determining the additional stator angular frequency according to the external system voltage phase angle and the stator phase angle based on a proportional-integral controller comprises:

[0013] Obtaining external system voltage phase angle and stator phase angle;

[0014] Determine a net phase angle difference according to an external system voltage phase angle and a stator phase angle;

[0015] An additional stator angular frequency corresponding to the net difference in phase angle is determined according to a proportional-integral controller.

[0016] Preferably, it also includes:

[0017] Obtaining stator output reactive power, stator output reactive power reference value and voltage reference value;

[0018] Determining a reactive power difference according to the stator output reactive power and a stator output reactive power reference value;

[0019] Determine the voltage value corresponding to the reactive power difference based on the proportional-integral controller;

[0020] The corresponding voltage amplitude is determined according to the voltage value and the voltage reference value.

[0021] Preferably, based on the active power control loop, determining the adjusted stator angular frequency and stator phase angle according to the stator output active power, the stator output active power reference value, the stator angular frequency reference value and the additional stator angular frequency includes:

[0022] Determining a frequency difference value according to a stator angular frequency reference value and an additional stator angular frequency;

[0023] Determine the frequency modulation amount based on the frequency difference and the droop coefficient;

[0024] Get inertia parameters;

[0025] Based on the integrator, the stator output active power, the stator output active power reference value, the frequency modulation amount and the adjusted stator phase angle and stator angular frequency corresponding to the inertia parameter are determined.

[0026] Preferably, the first control component and the second control component corresponding to the virtual impedance control are determined according to the stator three-phase current and the stator three-phase voltage, including:

[0027] Obtaining the stator three-phase current, and determining the stator current d-axis component and the stator current q-axis component based on the stator three-phase current and the stator phase angle;

[0028] Obtaining the stator three-phase voltage, and determining the stator voltage d-axis component and the stator voltage q-axis component based on the stator three-phase voltage and the stator phase angle;

[0029] Determining a d-axis control first component according to a stator current d-axis component and a first gain coefficient;

[0030] Determine a q-axis control first component according to a stator current q-axis component and a second gain coefficient;

[0031] Determining a q-axis control second component according to a stator current q-axis component and a first gain coefficient;

[0032] Determine a d-axis control second component according to a stator current d-axis component and a second gain coefficient;

[0033] Determine a first control component according to a d-axis control first component, a q-axis control first component, and a stator voltage d-axis component;

[0034] The second control component is determined according to the d-axis control second component, the q-axis control second component, and the stator voltage q-axis component.

[0035] Preferably, determining the first control component according to the d-axis control first component, the q-axis control first component and the stator voltage d-axis component includes:

[0036] Determine a first stator control component according to a first d-axis control component and a first q-axis control component;

[0037] Determine a d-axis component reference value according to the stator first control component and the voltage amplitude;

[0038] The first control component is determined according to the d-axis component reference value and the stator voltage d-axis component.

[0039] Preferably, determining the second control component according to the d-axis control second component, the q-axis control second component and the stator voltage q-axis component includes:

[0040] Determine the stator second control component according to the d-axis control second component and the q-axis control second component;

[0041] Determine a q-axis component reference value according to the stator second control component and zero;

[0042] The second control component is determined according to the q-axis component reference value and the stator voltage q-axis component.

[0043] Preferably, determining the rotor three-phase current, the first control component and the rotor three-phase voltage corresponding to the second control component based on the voltage control loop includes:

[0044] Determine a rotor current d-axis reference value and a rotor current q-axis reference value corresponding to the first control component and the second control component respectively based on a proportional-integral controller;

[0045] Obtaining the rotor three-phase current, and determining the corresponding rotor current d-axis component and rotor current q-axis component based on the rotor three-phase current and the rotor phase angle;

[0046] Determine a rotor current d-axis difference according to a rotor current d-axis reference value and a rotor current d-axis component, and determine a rotor voltage d-axis component corresponding to the rotor current d-axis difference based on a proportional-integral controller;

[0047] Determine a rotor current q-axis difference according to a rotor current q-axis reference value and a rotor current q-axis component, and determine a rotor voltage q-axis component corresponding to the rotor current q-axis difference based on a proportional-integral controller;

[0048] The rotor three-phase voltage is determined based on the rotor voltage d-axis component and the rotor voltage q-axis component.

[0049] On the other hand, the present application also provides an electronic device, including a memory for storing a computer program;

[0050] The processor is used to implement the steps of the above-mentioned grid-type doubly-fed wind turbine control method when executing a computer program.

[0051] On the other hand, the present application also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above-mentioned grid-type doubly-fed wind turbine control method are implemented.

[0052] A grid-type doubly-fed wind turbine control method provided in the present application is applied to a single doubly-fed wind turbine, including: determining an additional stator angular frequency according to an external system voltage phase angle and a stator phase angle based on a proportional-integral controller; determining an adjusted stator angular frequency and a stator phase angle based on an active power control loop according to stator output active power, a stator output active power reference value, a stator angular frequency reference value and an additional stator angular frequency; wherein the adjusted stator phase angle is the same as the external system voltage phase angle; determining a first control component and a second control component corresponding to a virtual impedance control according to a stator three-phase current and a stator three-phase voltage; determining a rotor three-phase current, a first control component and a second control component corresponding to a rotor three-phase voltage based on a voltage control loop; and determining the output voltage of the doubly-fed wind turbine according to the adjusted stator phase angle and the rotor three-phase voltage. It can be seen that the present application adjusts the stator phase angle to ensure that the adjusted stator phase angle is the same as the external system voltage phase angle, so as to meet the conditions for closing the box transformer, and avoid the problem of large phase angle errors between the three-phase AC voltages of multiple doubly-fed wind turbines connected to the grid and other doubly-fed wind turbines, thereby causing a large impact current problem for the entire grid-type doubly-fed wind turbine, and will not destroy the stability of the isolated system power grid. At the same time, the present application determines the first control component and the second control component according to the stator three-phase current and the stator three-phase voltage to realize the virtual impedance control of the unit, further ensuring that multiple doubly-fed wind turbines in the grid can be stably operated in parallel. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0054] FIG1 is a flow chart of a control method for a grid-connected doubly-fed wind turbine generator system provided by the present application;

[0055] FIG2 is a flowchart of operations corresponding to a phase presynchronization control link and an active power-frequency control link provided in an embodiment of the present application;

[0056] FIG3 is a flowchart of the operation corresponding to the reactive power-voltage control link provided in an embodiment of the present application;

[0057] FIG4 is a flowchart of operations corresponding to a virtual impedance control link and a voltage control link provided in an embodiment of the present application;

[0058] FIG5 is a structural diagram of a single doubly-fed wind turbine generator set provided in an embodiment of the present application;

[0059] FIG6 is a structural diagram of an electronic device provided in another embodiment of the present application. DETAILED DESCRIPTION

[0060] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0061] The core of this application is to provide a control method, electronic equipment and medium for a grid-type doubly-fed wind turbine generator set.

[0062] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0063] FIG1 is a flow chart of a control method for a grid-type doubly-fed wind turbine generator system provided by the present application, as shown in FIG1 , including the following process:

[0064] S10: Determine an additional stator angular frequency according to an external system voltage phase angle and a stator phase angle based on a proportional-integral controller.

[0065] S11: Based on the active power control loop, the adjusted stator angular frequency and stator phase angle are determined according to the stator output active power, the stator output active power reference value, the stator angular frequency reference value and the additional stator angular frequency; wherein the adjusted stator phase angle is the same as the external system voltage phase angle.

[0066] In a specific embodiment, the method is applied to a single doubly-fed wind turbine set. When multiple doubly-fed wind turbine sets are connected in parallel, a grid-type doubly-fed wind turbine set is formed. If there is a large phase angle error between the three-phase AC voltage of the single doubly-fed wind turbine set after grid connection and other doubly-fed wind turbine sets, a large impact current will be caused. Therefore, it is necessary to adjust it to ensure the final output voltage stability of the single doubly-fed wind turbine set, thereby ensuring the stability of the entire grid-type doubly-fed wind turbine set. Among them, step S10 constitutes the phase pre-synchronization control link in the control method of the grid-type doubly-fed wind turbine set, realizing the adjustment of the positioning phase angle of the stable voltage output; step S11 constitutes the active power-frequency control link in the control method of the grid-type doubly-fed wind turbine set.

[0067] In the process of determining the additional stator angular frequency based on the external system voltage phase angle and the stator phase angle based on the proportional-integral controller, if the proportional-integral controller determines that the external system voltage phase angle and the stator phase angle are different, the corresponding additional stator angular frequency is obtained, and the additional stator angular frequency at this time will affect the stator phase angle adjustment in step S11; if the proportional-integral controller determines that the external system voltage phase angle and the stator phase angle are the same, the corresponding additional stator angular frequency is obtained, and the additional stator angular frequency at this time will not actually affect the stator phase angle determined in step S11, because in this case the stator phase angle is equal to the adjusted stator phase angle. The specific parameters for determining the stator phase angle include: stator output active power, stator output active power reference value, stator angular frequency reference value and additional stator angular frequency.

[0068] S12: Determine a first control component and a second control component corresponding to the virtual impedance control according to the stator three-phase current and the stator three-phase voltage.

[0069] S13: Determine the rotor three-phase current, the first control component and the rotor three-phase voltage corresponding to the second control component based on the voltage control loop.

[0070] S14: Determine the output voltage of the doubly-fed wind generator according to the adjusted stator phase angle and the rotor three-phase voltage.

[0071] In a specific embodiment, since multiple double-fed wind turbines are connected to the grid, a grid-type double-fed wind turbine is formed, so it is important to ensure that the grid-type double-fed wind turbine can be stably operated in parallel. Step S12 constitutes the virtual impedance control link in the control method of the grid-type double-fed wind turbine; step S13 constitutes the voltage control link in the control method of the grid-type double-fed wind turbine.

[0072] In a specific embodiment, virtual impedance control is achieved through the first control component and the second control component, so that when multiple doubly-fed wind turbines are in stable parallel operation, subsynchronous oscillation and system instability will not be caused. In addition, the present application can determine the rotor three-phase voltage in the current grid-type doubly-fed wind turbine set based on the rotor three-phase current, the first control component and the second control component, and finally determine the output voltage of the doubly-fed wind turbine according to the adjusted stator phase angle and the rotor three-phase voltage, wherein the adjusted stator phase angle is determined according to the phase pre-synchronization control link and the active power-frequency control link, and the rotor three-phase voltage is determined according to the virtual impedance control link, so the obtained output voltage is relatively stable, so that the stable output voltage can be connected to the diode uncontrolled rectifier unit to provide a stable voltage on its AC side, so as to realize offshore power generation and transportation.

[0073] A grid-type doubly-fed wind turbine control method provided in the present application is applied to a single doubly-fed wind turbine, including: determining an additional stator angular frequency according to an external system voltage phase angle and a stator phase angle based on a proportional-integral controller; determining an adjusted stator angular frequency and a stator phase angle based on an active power control loop according to stator output active power, a stator output active power reference value, a stator angular frequency reference value and an additional stator angular frequency; wherein the adjusted stator phase angle is the same as the external system voltage phase angle; determining a first control component and a second control component corresponding to a virtual impedance control according to a stator three-phase current and a stator three-phase voltage; determining a rotor three-phase current, a first control component and a second control component corresponding to a rotor three-phase voltage based on a voltage control loop; and determining the output voltage of the doubly-fed wind turbine according to the adjusted stator phase angle and the rotor three-phase voltage. It can be seen that the present application adjusts the stator phase angle to ensure that the adjusted stator phase angle is the same as the external system voltage phase angle, so as to meet the conditions for closing the box transformer, and avoid the problem of large phase angle errors between the three-phase AC voltages of multiple doubly-fed wind turbines connected to the grid and other doubly-fed wind turbines, thereby causing a large impact current problem for the entire grid-type doubly-fed wind turbine, and will not destroy the stability of the isolated system power grid. At the same time, the present application determines the first control component and the second control component according to the stator three-phase current and the stator three-phase voltage to realize the virtual impedance control of the unit, further ensuring that multiple doubly-fed wind turbines in the grid can be stably operated in parallel.

[0074] On the basis of the above embodiment, as a preferred embodiment, the above S10 step: determining the additional stator angular frequency based on the external system voltage phase angle and the stator phase angle based on the proportional-integral controller, specifically includes: obtaining the external system voltage phase angle and the stator phase angle; determining the net phase angle difference based on the external system voltage phase angle and the stator phase angle; determining the additional stator angular frequency corresponding to the net phase angle difference according to the proportional-integral controller.

[0075] On the basis of the above embodiment, as a preferred embodiment, the above S11 step: based on the active power control loop, the adjusted stator angular frequency and stator phase angle are determined according to the stator output active power, the stator output active power reference value, the stator angular frequency reference value and the additional stator angular frequency, specifically including: determining the frequency difference according to the stator angular frequency reference value and the additional stator angular frequency; determining the frequency modulation amount according to the frequency difference and the droop coefficient; obtaining the inertia parameter; determining the adjusted stator phase angle and stator angular frequency corresponding to the stator output active power, the stator output active power reference value, the frequency modulation amount and the inertia parameter based on the integrator.

[0076] In a specific embodiment, as shown in FIG2 , step S10 constitutes a phase pre-synchronization control link in a grid-type doubly-fed wind turbine control method, in which the external system voltage phase angle θ is obtained. soand the stator phase angle θ s ; Under the Min module, determine the external system voltage phase angle θ so and the stator phase angle θ s The corresponding net difference in phase angle is as follows: the external system voltage phase angle θ so and the stator phase angle θ s The difference between them is taken as the corresponding net phase angle difference; then the net phase angle difference is calculated in the PI (Proportion Integral, proportional integral controller) to obtain the current additional stator angular frequency ω sadd .

[0077] In a specific embodiment, as shown in FIG2 , step S11 constitutes an active power-frequency control link in a grid-type doubly-fed wind turbine control method. In this link, the stator output active power P is obtained. s , stator output active power reference value P ref and additional stator angular frequency reference ω sref ; According to the additional stator angular frequency reference value ω sref and the additional stator angular frequency ω sadd The specific principle for determining the frequency difference is as follows: add the stator angular frequency reference value ω sref and the additional stator angular frequency ω sadd The difference between them is taken as the frequency difference; according to the frequency difference and the droop coefficient K v Determine the frequency modulation amount. The specific principle is: the frequency difference and the droop coefficient K v The product of is taken as the frequency modulation amount; at this time, according to the stator output active power P s , stator output active power reference value P ref The corresponding stator power difference can be determined; on this basis, the frequency difference and the stator power difference are combined and multiplied by the inertia parameter K J To get the current frequency data; the current frequency data at this time is subjected to two PI operations, and then the angle conversion Mod 2π is performed to get the adjusted stator phase angle θ s When the current frequency data undergoes a PI operation, the stator angular frequency ω can be obtained. s .

[0078] It should be noted that this application is only one possible implementation method, but is not limited to this implementation method and can be set according to user needs.

[0079] The embodiment of the present application provides a specific process for adjusting the stator phase angle, during which the adjusted stator phase angle is ensured to be the same as the external system voltage phase angle, so as to meet the conditions for closing the box transformer, avoid the problem of large phase angle error between the three-phase AC voltage of a single doubly-fed wind turbine set after grid connection and other doubly-fed wind turbine sets, thereby causing a large impact current, and will not destroy the stability of the isolated system power grid.

[0080] On the basis of the above embodiments, as a preferred embodiment, the specific steps of obtaining the voltage amplitude include: obtaining the stator output reactive power, the stator output reactive power reference value and the voltage reference value; determining the reactive power difference according to the stator output reactive power and the stator output reactive power reference value; determining the voltage value corresponding to the reactive power difference based on a proportional-integral controller; and determining the voltage amplitude corresponding to the voltage value and the voltage reference value.

[0081] On the basis of the above embodiment, as a preferred embodiment, the above S12 step determines the first control component and the second control component corresponding to the virtual impedance according to the stator three-phase current and the stator three-phase voltage, specifically including: obtaining the stator three-phase current, and determining the stator current d-axis component and the stator current q-axis component based on the stator three-phase current and the stator phase angle; obtaining the stator three-phase voltage, and determining the stator voltage d-axis component based on the stator three-phase voltage and the stator phase angle; determining the d-axis control first component according to the stator current d-axis component and the first gain coefficient; determining the q-axis control first component according to the stator current q-axis component and the second gain coefficient; determining the q-axis control second component according to the stator current q-axis component and the first gain coefficient; determining the d-axis control second component according to the stator current d-axis component and the second gain coefficient; determining the first control component according to the d-axis control first component, the q-axis control first component and the stator voltage d-axis component; determining the second control component according to the d-axis control second component, the q-axis control second component and the stator voltage q-axis component. Among them, determining the first control component according to the d-axis control first component, the q-axis control first component and the stator voltage d-axis component specifically includes: determining the stator first control component according to the d-axis control first component and the q-axis control first component; determining the d-axis component reference value according to the stator first control component and the voltage amplitude; determining the first control component according to the d-axis component reference value and the stator voltage d-axis component. Determining the second control component according to the d-axis control second component, the q-axis control second component and the stator voltage q-axis component specifically includes: determining the stator second control component according to the d-axis control second component and the q-axis control second component; determining the q-axis component reference value according to the stator second control component and zero; determining the second control component according to the q-axis component reference value and the stator voltage q-axis component.

[0082] On the basis of the above embodiment, as a preferred embodiment, the above S13 step: determining the rotor three-phase current, the rotor three-phase voltage corresponding to the first control component and the second control component based on the voltage control loop, specifically includes: determining the rotor current d-axis reference value and the rotor current q-axis reference value corresponding to the first control component and the second control component respectively based on the proportional-integral controller; obtaining the rotor three-phase current, and determining the corresponding rotor current d-axis component and the rotor current q-axis component based on the rotor three-phase current and the rotor phase angle; determining the rotor current d-axis difference according to the rotor current d-axis reference value and the rotor current d-axis component, and determining the rotor voltage d-axis component corresponding to the rotor current d-axis difference based on the proportional-integral controller; determining the rotor current q-axis difference according to the rotor current q-axis reference value and the rotor current q-axis component, and determining the rotor voltage q-axis component corresponding to the rotor current q-axis difference based on the proportional-integral controller; determining the rotor three-phase voltage according to the rotor voltage d-axis component and the rotor voltage q-axis component.

[0083] In a specific embodiment, the voltage amplitude needs to be obtained first, as shown in FIG3 . The obtained voltage amplitude constitutes a reactive-voltage control link in the control method of a grid-type doubly-fed wind turbine generator set. In this link, the stator output reactive power Q is obtained. s , stator output reactive power reference value Q ref And voltage reference value U ref ; Then the stator outputs reactive power Q s And stator output reactive power reference value Q ref The difference between them is taken as the reactive power difference; and the voltage value corresponding to the reactive power difference is determined based on the PI operation; the voltage value U ref Perform sum and difference calculation with the voltage reference value to obtain the corresponding voltage amplitude U s .

[0084] Then, as shown in FIG4 , step S12 constitutes the virtual impedance control link in the control method of the grid-type doubly-fed wind turbine generator set, and step S13 constitutes the voltage control link in the control method of the grid-type doubly-fed wind turbine generator set. In these two links, the stator three-phase current I sabc , and based on the stator three-phase current I sabc and the stator phase angle θ s Determine the stator current d-axis component I sd and the q-axis component of the stator current I sq The principle is: for the stator three-phase current I sabc Perform coordinate transformation operation (Park) to convert the three-phase rotating coordinate system into the two-phase rotating coordinate system. Obtain the stator three-phase voltage U sabc , and based on the stator three-phase voltage U sabc and the stator phase angle θ s Determine the stator voltage d-axis component U sdand the q-axis component of the stator current U sq The principle is: for the stator three-phase voltage U sabc A coordinate system conversion operation (Park) is performed to convert the three-phase rotating coordinate system into the two-phase rotating coordinate system.

[0085] Then according to the stator current d-axis component I sd and the first gain factor R v Determine the first d-axis control component; according to the stator current q-axis component I sq and the second gain coefficient ɷL v Determine the first q-axis control component; according to the stator current q-axis component I sq and the first gain factor R v Determine the second component of q-axis control; according to the d-axis component of the stator current and the second gain coefficient ɷL v Determine the second component of d-axis control; the specific principle is: the stator current d-axis component I sd and the first gain factor R v The product is used as the first component of the d-axis control; the q-axis component of the stator current I sq 、The second gain coefficient ɷL v The product of the complex imaginary part j is used as the first component of q-axis control; the q-axis component of the stator current I sq and the first gain factor R v The product of is used as the second component of q-axis control; the stator current d-axis component I sd 、The second gain coefficient ɷL v The product of the complex imaginary part j serves as the d-axis control second component.

[0086] Perform a sum operation on the first d-axis control component and the first q-axis control component to obtain the corresponding stator first control component U svd ; Perform a sum operation on the second d-axis control component and the second q-axis control component to obtain the corresponding stator second control component U svq ; Then the stator first control component U svd With voltage amplitude U s and the stator voltage d-axis component U sd Perform sum and difference operations to obtain the first control component; convert the stator voltage q-axis component U svq The second control component is obtained by performing sum and difference operations with the zero and stator voltage q-axis components, and then PI operations are performed on the first control component and the second control component respectively. At this point, the stator voltage control link in the virtual impedance control link and the voltage control link is completed.

[0087] In the rotor current control link in the voltage control link, the rotor current d-axis reference values ​​I corresponding to the first control component and the second control component are determined based on the PI operation. rdref and the rotor current q-axis reference value Irqref . Get the rotor three-phase current I rabc , and determine the corresponding rotor current d-axis component I based on the rotor three-phase current rd and the q-axis component of the rotor current I rq . Set the rotor current d-axis reference value I rdref and the rotor current d-axis component I rd The difference is taken as the rotor current d-axis difference; the rotor current q-axis reference value I rqref and the q-axis component of the rotor current I rq The difference is taken as the rotor current q-axis difference. Then, the rotor voltage d-axis component U corresponding to the rotor current d-axis difference is determined based on the PI operation. rd ; Based on the proportional-integral controller, the rotor voltage q-axis component U corresponding to the rotor current q-axis difference is determined rq Finally, the d-axis component of the rotor voltage U rd and the q-axis component of the rotor voltage U rq Perform coordinate transformation operation (iPark) from the two-phase rotating coordinate system to the three-phase rotating coordinate system to obtain the rotor three-phase voltage U rabc .

[0088] It should be noted that the embodiment provided in the present application is only one possible implementation method, but is not limited to only this implementation method and can be set according to the needs of the user.

[0089] When the control method for a grid-type doubly-fed wind turbine provided by the present application is applied to the doubly-fed wind turbine as shown in FIG5 , a single-unit black start of a single doubly-fed wind turbine can also be achieved, which includes the following steps:

[0090] 1. The DC side energy storage charges the converter bus voltage through the DC / DC converter and maintains the bus capacitor voltage at the rated value.

[0091] 2. Start the machine-side converter and control the rotor current and voltage to excite the stator of the doubly-fed wind turbine. First, establish a stator voltage of 20% of the rated voltage.

[0092] 3. Close KM1~KM3, connect the stator and rotor of the doubly-fed wind turbine, start the grid-side converter and supply power to the auxiliary power supply system of the wind turbine.

[0093] 4. Gradually increase the stator voltage to the rated value, close QF1~QF3, realize the black start of the doubly fed wind turbine, and connect it to the external system, that is, build a grid-type doubly fed wind turbine set.

[0094] In summary, a grid-type doubly-fed wind turbine control method provided in the present application is applied to a single doubly-fed wind turbine, including: determining an additional stator angular frequency based on an external system voltage phase angle and a stator phase angle based on a proportional-integral controller; determining an adjusted stator angular frequency and a stator phase angle based on an active power control loop according to the stator output active power, a stator output active power reference value, a stator angular frequency reference value and an additional stator angular frequency; wherein the adjusted stator phase angle is the same as the external system voltage phase angle; determining a first control component and a second control component corresponding to a virtual impedance control according to the stator three-phase current and the stator three-phase voltage; determining a rotor three-phase current, a first control component and a second control component corresponding to the rotor three-phase voltage based on a voltage control loop; and determining the output voltage of the doubly-fed wind turbine according to the adjusted stator phase angle and the rotor three-phase voltage. It can be seen that the present application adjusts the stator phase angle to ensure that the adjusted stator phase angle is the same as the external system voltage phase angle, so as to meet the conditions for closing the box transformer, and avoid the problem of large phase angle errors between the three-phase AC voltages of multiple doubly-fed wind turbines and other doubly-fed wind turbines after grid connection, thereby causing a large impact current to the entire grid-type doubly-fed wind turbine, and will not destroy the stability of the isolated system power grid. At the same time, the present application determines the first control component and the second control component according to the stator three-phase current and the stator three-phase voltage to realize the virtual impedance control of the unit, and further ensures that the multiple doubly-fed wind turbines in the grid connection can be stably operated in parallel. And the control method of the grid-type doubly-fed wind turbine provided by the present application, when applied to a single doubly-fed wind turbine, can also realize the black start of a single doubly-fed wind turbine.

[0095] FIG6 is a structural diagram of an electronic device provided by another embodiment of the present application. As shown in FIG6 , the electronic device includes: a memory 20 for storing a computer program;

[0096] The processor 21 is used to implement the steps of the control method of the grid-type doubly-fed wind turbine generator set mentioned in the above embodiment when executing the computer program.

[0097] The electronic device provided in this embodiment may include but is not limited to a smart phone, a tablet computer, a laptop computer or a desktop computer.

[0098] Among them, the processor 21 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 21 can be implemented in at least one hardware form of a digital signal processor (DSP), a field-programmable gate array (FPGA), and a programmable logic array (PLA). The processor 21 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a central processing unit (CPU); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 21 may be integrated with a graphics processing unit (GPU), which is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 21 may also include an artificial intelligence (AI) processor, which is used to process computing operations related to machine learning.

[0099] The memory 20 may include one or more computer-readable storage media, which may be non-transitory. The memory 20 may also include a high-speed random access memory, and a non-volatile memory, such as one or more disk storage devices, flash memory storage devices. In this embodiment, the memory 20 is at least used to store the following computer program 201, wherein, after the computer program is loaded and executed by the processor 21, it can implement the relevant steps of the grid-type doubly fed wind turbine control method disclosed in any of the aforementioned embodiments. In addition, the resources stored in the memory 20 may also include an operating system 202 and data 203, etc., and the storage method may be temporary storage or permanent storage. Among them, the operating system 202 may include Windows, Unix, Linux, etc.

[0100] In some embodiments, the electronic device may further include a display screen 22 , an input / output interface 23 , a communication interface 24 , a power source 25 , and a communication bus 26 .

[0101] Those skilled in the art will appreciate that the structure shown in FIG. 6 does not limit the electronic device and may include more or fewer components than those shown in the figure.

[0102] The electronic device provided in the embodiment of the present application includes a memory and a processor. When the processor executes the program stored in the memory, it can implement the above-mentioned grid-type doubly-fed wind turbine control method and has the same beneficial effects.

[0103] Finally, the present application also provides an embodiment corresponding to a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps recorded in the above method embodiment are implemented.

[0104] It is understandable that if the method in the above embodiment is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk and other media that can store program code.

[0105] The above is a detailed introduction to a grid-type doubly-fed wind turbine control method, electronic device and medium provided by the present application. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can refer to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can refer to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

[0106] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A control method for a grid-type doubly-fed wind turbine generator system, characterized in that: Applied to a single doubly-fed wind turbine generator set, including: Determining an additional stator angular frequency according to an external system voltage phase angle and a stator phase angle based on a proportional-integral controller; Based on the active power control loop, determining the adjusted stator angular frequency and the stator phase angle according to the stator output active power, the stator output active power reference value, the stator angular frequency reference value and the additional stator angular frequency; wherein the adjusted stator phase angle is the same as the external system voltage phase angle; Determine a first control component and a second control component corresponding to the virtual impedance control according to the stator three-phase current and the stator three-phase voltage; Determine, based on a voltage control loop, a rotor three-phase current, a rotor three-phase voltage corresponding to the first control component, and the second control component; The output voltage of the doubly-fed wind generator is determined according to the adjusted stator phase angle and the rotor three-phase voltage.

2. The control method of a grid-type doubly-fed wind turbine generator system according to claim 1, characterized in that: The method of determining the additional stator angular frequency based on the proportional-integral controller according to the external system voltage phase angle and the stator phase angle comprises: Acquiring the external system voltage phase angle and the stator phase angle; Determining a net phase angle difference according to the external system voltage phase angle and the stator phase angle; The additional stator angular frequency corresponding to the net phase angle difference is determined according to the proportional-integral controller.

3. The control method of a grid-type doubly-fed wind turbine generator system according to claim 1, characterized in that: Also includes: Obtaining stator output reactive power, stator output reactive power reference value and voltage reference value; Determining a reactive power difference according to the stator output reactive power and the stator output reactive power reference value; Determine a voltage value corresponding to the reactive power difference based on the proportional-integral controller; A corresponding voltage amplitude is determined according to the voltage value and the voltage reference value.

4. The control method of a grid-type doubly-fed wind turbine generator system according to claim 1, characterized in that: The active power control loop is based on determining the adjusted stator angular frequency and the stator phase angle according to the stator output active power, the stator output active power reference value, the stator angular frequency reference value and the additional stator angular frequency, including: determining a frequency difference value according to the stator angular frequency reference value and the additional stator angular frequency; Determine the frequency modulation amount according to the frequency difference and the droop coefficient; Get inertia parameters; The stator output active power, the stator output active power reference value, the frequency modulation amount and the adjusted stator phase angle and the stator angular frequency corresponding to the inertia parameter are determined based on an integrator.

5. The control method of a grid-type doubly-fed wind turbine generator system according to claim 3, characterized in that: The first control component and the second control component corresponding to the virtual impedance control are determined according to the stator three-phase current and the stator three-phase voltage, including Acquire the stator three-phase current, and determine the stator current d-axis component and the stator current q-axis component based on the stator three-phase current and the stator phase angle; Acquire the stator three-phase voltage, and determine the stator voltage d-axis component and the stator voltage q-axis component based on the stator three-phase voltage and the stator phase angle; Determining a d-axis control first component according to the stator current d-axis component and a first gain coefficient; Determine a q-axis control first component according to the stator current q-axis component and the second gain coefficient; Determining a q-axis control second component according to the stator current q-axis component and the first gain coefficient; Determining a d-axis control second component according to the stator current d-axis component and the second gain coefficient; determining the first control component according to the d-axis control first component, the q-axis control first component and the stator voltage d-axis component; The second control component is determined according to the d-axis control second component, the q-axis control second component, and the stator voltage q-axis component.

6. The control method of a grid-type doubly-fed wind turbine generator system according to claim 5, characterized in that: The determining the first control component according to the d-axis control first component, the q-axis control first component and the stator voltage d-axis component comprises: Determine a first stator control component according to the first d-axis control component and the first q-axis control component; Determine a d-axis component reference value according to the stator first control component and the voltage amplitude; The first control component is determined according to the d-axis component reference value and the stator voltage d-axis component.

7. The control method of a grid-type doubly-fed wind turbine generator system according to claim 5, characterized in that: The determining the second control component according to the d-axis control second component, the q-axis control second component and the stator voltage q-axis component comprises: Determine a stator second control component according to the d-axis control second component and the q-axis control second component; Determine a q-axis component reference value according to the stator second control component and zero; The second control component is determined according to the q-axis component reference value and the stator voltage q-axis component.

8. The control method for a grid-connected doubly-fed wind turbine generator system according to any one of claims 1 to 7, characterized in that: The determining, based on a voltage control loop, the rotor three-phase current, the first control component, and the rotor three-phase voltage corresponding to the second control component comprises: Determine, based on the proportional-integral controller, a rotor current d-axis reference value and a rotor current q-axis reference value corresponding to the first control component and the second control component, respectively; Acquire the rotor three-phase current, and determine the corresponding rotor current d-axis component and rotor current q-axis component based on the rotor three-phase current and the rotor phase angle; Determine a rotor current d-axis difference according to the rotor current d-axis reference value and the rotor current d-axis component, and determine a rotor voltage d-axis component corresponding to the rotor current d-axis difference based on the proportional-integral controller; Determine a rotor current q-axis difference according to the rotor current q-axis reference value and the rotor current q-axis component, and determine a rotor voltage q-axis component corresponding to the rotor current q-axis difference based on the proportional-integral controller; The rotor three-phase voltage is determined according to the rotor voltage d-axis component and the rotor voltage q-axis component.

9. An electronic device, characterized in that: comprising a memory for storing a computer program; A processor is used to implement the steps of the grid-type doubly-fed wind turbine control method as described in any one of claims 1 to 8 when executing the computer program.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the grid-type doubly-fed wind turbine control method according to any one of claims 1 to 8 are implemented.

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