Permanent magnet direct drive fan side converter control method and device and electronic equipment

Abstract

The invention provides a permanent magnet direct drive fan side converter control method and device and electronic equipment, and the method comprises the steps: obtaining the frequency change information of a power grid side of a permanent magnet direct drive fan grid-connected system, determining the working state of the power grid side based on the frequency change information, and enabling the working state to be divided into a normal state and a frequency change state, according to the method, the working states of the permanent magnet direct-drive fan grid-connected system and the control rules corresponding to the working states are utilized to control the machine-side converter of the permanent magnet direct-drive fan grid-connected system, different control methods can be adopted to control the machine-side converter in different working states such as the power grid side normal state and the frequency change state, and therefore the frequency supporting capacity of a wind power system is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of wind power grid-connected systems, and in particular to a control method, device and electronic equipment for a permanent magnet direct-drive wind turbine side converter. Background Art

[0002] Under the background of the "dual carbon" policy, the control technology of permanent magnet direct-drive wind turbines has gradually become a research hotspot. Usually, permanent magnet direct-drive wind turbines are connected to the grid through back-to-back converters, which have better dynamic response effects. However, due to the isolation effect of the back-to-back converter, the impact of system frequency changes on wind turbines is weakened, and the moment of inertia is 0, that is, the motor speed is independent of the frequency under the maximum power control mode, which will affect the frequency stability when wind turbines are connected to the grid on a large scale. In this context, studying the control method for the stable operation of the machine converter of the permanent magnet direct-drive wind turbine grid-connected system under various working conditions is of great significance to improving the frequency support capability of the wind power system. Summary of the invention

[0003] The present disclosure proposes a method, device and electronic equipment for controlling a permanent magnet direct-drive wind turbine side converter, aiming to solve one of the technical problems in the related art at least to a certain extent.

[0004] The first aspect of the present disclosure proposes a method for controlling a machine-side converter of a permanent magnet direct-drive wind turbine, comprising obtaining frequency change information on the grid side of a permanent magnet direct-drive wind turbine grid-connected system; determining a working state on the grid side based on the frequency change information, wherein the working state is divided into a normal state and a frequency change state; and controlling the machine-side converter of the permanent magnet direct-drive wind turbine grid-connected system using a control rule corresponding to the working state.

[0005] The second aspect of the present disclosure proposes a permanent magnet direct-drive wind turbine machine-side converter control device, including: an acquisition module, used to acquire frequency change information on the grid side of the permanent magnet direct-drive wind turbine grid-connected system; a determination module, used to determine the working state of the grid side based on the frequency change information, wherein the working state is divided into a normal state and a frequency change state; and a control module, used to control the machine-side converter of the permanent magnet direct-drive wind turbine grid-connected system using a control rule corresponding to the working state.

[0006] The third aspect embodiment of the present disclosure proposes an electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the permanent magnet direct-drive wind turbine side converter control method of the embodiment of the present disclosure.

[0007] The fourth aspect of the present disclosure provides a non-transitory computer-readable storage medium storing computer instructions, wherein the computer instructions are used to enable the computer to execute the permanent magnet direct-drive wind turbine side converter control method disclosed in the embodiment of the present disclosure.

[0008] In this embodiment, the frequency change information of the grid side of the permanent magnet direct-drive wind turbine grid-connected system is obtained, and the working state of the grid side is determined based on the frequency change information, wherein the working state is divided into a normal state and a frequency change state, and the control rules corresponding to the working state are used to control the machine-side converter of the permanent magnet direct-drive wind turbine grid-connected system. Different control methods can be used to control the machine-side converter in different working states such as the normal state and the frequency change state of the grid side, thereby improving the frequency support capability of the wind power system.

[0009] Additional aspects and advantages of the present disclosure will be given in part in the following description and in part will be obvious from the following description or learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The above and / or additional aspects and advantages of the present disclosure will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0011] Figure 1 It is a flow chart of a method for controlling a permanent magnet direct-drive wind turbine side converter according to an embodiment of the present disclosure;

[0012] Figure 2 It is a structural schematic diagram of a permanent magnet direct-drive wind turbine grid-connected system provided according to an embodiment of the present disclosure;

[0013] Figure 3 is a schematic diagram of a permanent magnet direct-drive wind turbine side converter control device provided according to another embodiment of the present disclosure;

[0014] Figure 4 A block diagram of an exemplary electronic device suitable for implementing embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0015] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0016] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0017] It should be noted that the executor of the permanent magnet direct-drive wind turbine machine-side converter control method of this embodiment may be a permanent magnet direct-drive wind turbine machine-side converter control device, which may be implemented by software and / or hardware, and which may be configured in an electronic device, which may include but is not limited to a terminal, a server, etc.

[0018] Figure 1 is a flow chart of a method for controlling a permanent magnet direct-drive wind turbine side converter according to an embodiment of the present disclosure, such as Figure 1 As shown, the method includes:

[0019] S101: Obtain frequency change information on the grid side of the permanent magnet direct-drive wind turbine grid-connected system.

[0020] Figure 2 is a structural schematic diagram of a permanent magnet direct drive wind turbine grid-connected system provided according to an embodiment of the present disclosure, such as Figure 2 As shown, the permanent magnet direct-drive wind turbine grid-connected system of this embodiment includes a wind turbine, a permanent magnet synchronous generator (PMSG), a machine-side converter, and a grid-side converter, wherein the machine-side converter and the grid-side converter are respectively configured with a control system. The permanent magnet direct-drive wind turbine machine-side converter control method of the disclosed embodiment can be executed by the machine-side converter control system.

[0021] Specifically, the machine-side converter control system of this embodiment first obtains the frequency change information on the grid side of the permanent magnet direct-drive wind turbine grid-connected system, and the frequency change information can represent the frequency change situation on the grid side.

[0022] S102: Determine the working state of the power grid side based on the frequency change information.

[0023] Furthermore, this embodiment can determine the working status of the power grid side based on the frequency change information.

[0024] Among them, for example, when the frequency change information indicates that the frequency on the grid side has not changed, it can be determined that the working state of the grid side (hereinafter referred to as the "grid side") is a normal state; for another example, when the frequency change information indicates that the frequency on the grid side has changed, it can be determined that the working state of the grid side is a frequency change state, that is, the working state of the grid side in the embodiment of the present disclosure is divided into a normal state and a frequency change state.

[0025] S103: Controlling the machine-side converter of the permanent magnet direct-drive wind turbine grid-connected system by using a control rule corresponding to the working state.

[0026] That is to say, the machine-side converter control system of the embodiment of the present disclosure can adopt corresponding control rules (or control methods) to control the machine-side converter according to different working states of the grid side.

[0027] In some embodiments, when the working state is normal, the control rule is, for example, that the machine-side converter adopts the maximum power tracking control method, and adopts the control rules of "zero d-axis control", "torque outer loop (maximum power tracking), q-axis current inner loop" according to the mathematical model formula about the dq axis.

[0028] Specifically, this embodiment can monitor the current wind speed. When the current wind speed is greater than the cut-in wind speed and less than the rated wind speed, the wind turbine maintains the grid-connected state, ensures that the wind turbine pitch angle is 0, and through the optimal torque control strategy, the wind turbine operates at the optimal wind energy utilization coefficient to maximize the wind energy utilization rate. In view of this, this embodiment can calculate the current maximum power of the permanent magnet direct-drive generator based on the current air density, the electrical angular velocity of the generator, the radius of the wind wheel, the maximum wind energy utilization coefficient, the optimal blade tip speed ratio, and the local power coefficient; further, the maximum torque is calculated based on the maximum power, wherein the ratio of the maximum power to the electrical angular velocity of the generator is the maximum torque.

[0029] In some embodiments, the maximum power and the maximum torque may be calculated according to the following formula:

[0030]

[0031] Among them, P opt Indicates the current maximum power; T opt represents the maximum torque; ρ is the current air density; ω s is the electrical angular velocity of the generator; R is the radius of the wind wheel; C Pmax is the maximum wind energy utilization coefficient; opt is the optimal tip speed ratio; G is the local power coefficient; K opt is the optimal control coefficient of torque.

[0032] Furthermore, the difference between the maximum torque and the current torque of the permanent magnet direct-drive generator is calculated, and the input of the active current loop of the machine-side converter is determined based on the difference, so as to achieve the control target of maximum power tracking.

[0033] In some embodiments, when it is monitored that the current wind speed is greater than the rated wind speed and less than the cut-out wind speed, the maximum torque is limited (i.e., the maximum torque value is limited), and a variable pitch system is introduced to adjust the pitch angle so that the wind turbine operates at rated power.

[0034] It can be understood that the rated wind speed, cut-in wind speed, cut-out wind speed, and rated power of this embodiment can be flexibly set according to the actual application scenario, and there is no limitation on this.

[0035] In other embodiments, when the working state of the grid side is a frequency change state, that is, the frequency changes on the grid side, due to the isolation effect of the back-to-back converter, the impact of the system frequency change on the wind turbine is weakened, and the moment of inertia is 0. In order to enable the wind turbine to have the ability to respond to grid frequency changes, a control link related to the frequency change is added to the machine-side converter control, and the converter active reference value is changed by adding virtual power, thereby indirectly releasing or storing the kinetic energy of the wind turbine rotor, thereby achieving a rapid change in the wind turbine output active power.

[0036] Specifically, this embodiment first calculates the current maximum power of the permanent magnet direct-drive generator based on the current air density, the electrical angular velocity of the generator, the radius of the wind wheel, the maximum wind energy utilization coefficient, the optimal tip speed ratio, and the local power coefficient, and calculates the maximum torque based on the maximum power. The calculation method is the same as that of the above embodiment and will not be repeated here.

[0037] Furthermore, this embodiment calculates the auxiliary torque based on the system frequency deviation (deviation between the actual frequency and the rated frequency) on the grid side.

[0038] In some embodiments, the auxiliary torque is calculated according to the following formula:

[0039]

[0040] Among them, P vir is the auxiliary torque, Δf is the system frequency deviation; k p and k d are the proportional coefficient and differential coefficient of additional virtual power control respectively.

[0041] Furthermore, when the machine-side converter adds virtual inertia control (ie, virtual torque) and adopts torque outer loop control, this embodiment can be based on the maximum torque and the auxiliary torque P vir The sum of the two determines the q-axis reference current, and the q-axis reference current is used as the input of the torque outer loop control of the machine-side converter.

[0042] In some embodiments, the q-axis reference current is determined according to the following formula:

[0043]

[0044] in, represents the q-axis reference current, p n represents the number of pole pairs of the permanent magnet direct drive generator, ψ f Represents the rotor flux.

[0045] in, P MPPT represents the maximum torque, ω s represents the electrical angular velocity of the generator, we can get:

[0046]

[0047] Therefore, in this control link, the auxiliary torque is calculated and superimposed on the maximum torque calculated by the outer loop of the machine-side torque according to the wind speed, and the sum of the two is used as the new torque tracking amount to achieve the control target of inertia response.

[0048] In some embodiments, the wind farm should have primary frequency regulation capability, and its active power variation should satisfy:

[0049]

[0050] Among them, ΔP t is the change in active power of the wind farm; K f is the active frequency modulation coefficient; Δf is the power system frequency deviation; f N is the rated frequency of the power system; P t is the active power of the wind farm. This power change can also be converted into an impact on the torque and superimposed on the torque reference to form an optimal torque that includes MPPT, inertia response, and primary frequency modulation power change.

[0051] In some embodiments, in the above-mentioned machine-side converter control method, in order to prevent a sudden change in the active current output by the grid-side converter during fault ride-through from causing a sudden change in the charging and discharging current of the DC side capacitor, it is necessary to set upper and lower limits of the active current in the converter active current control link.

[0052] In this embodiment, the frequency change information of the grid side of the permanent magnet direct-drive wind turbine grid-connected system is obtained, and the working state of the grid side is determined based on the frequency change information, wherein the working state is divided into a normal state and a frequency change state, and the control rules corresponding to the working state are used to control the machine-side converter of the permanent magnet direct-drive wind turbine grid-connected system. Different control methods can be used to control the machine-side converter in different working states such as the normal state and the frequency change state of the grid side, thereby improving the frequency support capability of the wind power system.

[0053] Some other embodiments further provide a method for controlling a grid-side converter of a permanent magnet direct-drive wind turbine, the method comprising the following steps:

[0054] S201: Acquire target information on the grid side of the permanent magnet direct-drive wind turbine grid-connected system.

[0055] like Figure 2 As shown, the permanent magnet direct-drive wind turbine grid-side converter control method of the embodiment of the present disclosure can be executed by a grid-side converter control system.

[0056] Specifically, the grid-side converter control system of this embodiment first obtains information on the grid side of the permanent magnet direct-drive wind turbine grid-connected system, which is called target information. The target information may include current information, voltage information and any other possible information on the grid side, without limitation.

[0057] S202: Determine the working status of the power grid side based on the target information.

[0058] Furthermore, this embodiment can determine the working status of the grid side based on target information such as current information and voltage information.

[0059] Among them, for example, when the current information and the voltage information are both within the normal range, it can be determined that the working state of the power grid side (hereinafter referred to as the "grid side") is normal; for another example, when the current information is abnormal, it can be determined that a short circuit fault (including symmetrical faults and asymmetrical faults) occurs on the grid side, that is, the working state is a short circuit fault state; for another example, when the voltage information is abnormal, it can be determined that a voltage surge fault occurs on the grid side, that is, the working state is a voltage surge state.

[0060] S203: Control the grid-side converter of the permanent magnet direct-drive wind turbine grid-connected system by using a control rule corresponding to the working state.

[0061] That is to say, the grid-side converter control system of the embodiment of the present disclosure can adopt corresponding control rules (or control methods) to control the grid-side converter according to different working states of the grid side.

[0062] In some embodiments, when the working state is normal, the function of the grid-side converter control system is, on the one hand, to ensure the constancy of the DC bus voltage and prevent the wind turbine from being disconnected from the grid due to excessive DC bus voltage; on the other hand, the DC voltage output by the machine-side converter is converted into a three-phase voltage with the same amplitude and frequency as the grid voltage through the inverter. In view of this, the control rule of the grid-side converter in this embodiment adopts the d and q axis components of the grid-side current to form an active current loop and a reactive current loop double current inner loop control circuit, and controls the active power and reactive power absorbed by the grid by controlling the two current loops respectively. Under normal working conditions, the grid-side converter adopts the control method of "DC side voltage outer loop, d axis current inner loop", "reactive power outer loop, q axis current inner loop" according to the mathematical model formula about the dq axis.

[0063] Specifically, this embodiment can calculate the d-axis control voltage and q-axis control voltage of the grid-side converter based on the grid-side equivalent inductance, the actual d-axis and q-axis currents of the grid-side, the actual d-axis and q-axis voltages of the grid-side, the synchronous electrical angular velocity of the power grid, and the grid-side equivalent resistance.

[0064] In some embodiments, the d-axis control voltage and the q-axis control voltage are calculated according to the following formula (1):

[0065]

[0066] Among them, v gd 、v gq They represent the d-axis control voltage and q-axis control voltage of the grid-side converter, respectively. g is the grid-side equivalent inductance; i gd 、i gq are the actual currents of the d-axis and q-axis on the grid side respectively; u gd 、u gq are the actual voltages of the d-axis and q-axis on the grid side respectively; ω g is the synchronous electrical angular velocity of the power grid; R g is the grid side equivalent resistance.

[0067] Furthermore, inputs of the active current loop and the reactive current loop of the grid-side converter are determined based on the d-axis control voltage and the q-axis control voltage to control active power and reactive power.

[0068] In practical applications, the tracking error of the grid-side active power (actual voltage on the d-axis) to its reference value is used as the reference input of the active current loop after PI adjustment; the error between the actual value of the grid-side reactive power (actual voltage on the q-axis) and its reference value is used as the reference input of the reactive current loop after PI adjustment. Figure 3 is a schematic diagram of a grid-side converter control strategy provided according to an embodiment of the present disclosure, such as Figure 3 As shown, the above formula (1) is transformed into the control strategy:

[0069]

[0070] Among them, k p , k i are the proportional coefficient and integral coefficient of the PI controller respectively; i gd.ref 、i gq.ref They are the reference values ​​of the active current loop and the reactive current loop, respectively. When the wind turbine is normally connected to the grid, the reference value of the reactive current control loop is set to 0, so that the power absorbed by the grid is all active power. When a grid failure occurs, certain measures need to be taken to suppress the overvoltage and fluctuation of the DC bus voltage, and to provide reactive support for the recovery of the grid, so that the wind turbine remains connected to the grid.

[0071] In other embodiments, when the working state is a short-circuit fault state (including symmetrical faults and asymmetrical faults), the corresponding control rule is to use the positive and negative sequence decomposition method to decompose the three-phase current and voltage on the grid side into positive and negative sequence dq axis components, and perform closed-loop control on the positive and negative sequence dq axis components respectively, with the control target being that there is no negative sequence current component on the grid side, and the current reference value is shown in Formula 3. At this time, the given reactive current control loop reference value is not 0:

[0072]

[0073] in: are the given reference values ​​of the positive sequence dq axis and negative sequence dq axis current inner loop respectively; P ref , Q ref It is the reference value of active power and reactive power; is the positive sequence voltage amplitude.

[0074] In this embodiment, the d-axis and q-axis positive-sequence control voltage and the d-axis and q-axis negative-sequence control voltage of the grid-side converter can be calculated based on the actual positive-sequence current of the grid-side d-axis and q-axis, the actual positive-sequence voltage of the grid-side d-axis and q-axis, the actual negative-sequence current of the grid-side d-axis and q-axis, the actual negative-sequence voltage of the grid-side d-axis and q-axis, the grid-side equivalent resistance, and the synchronous electrical angular velocity of the power grid.

[0075] In some embodiments, the d-axis and q-axis positive sequence control voltages and the d-axis and q-axis negative sequence control voltages of the grid-side converter are calculated according to the following formulas (4) and (5):

[0076]

[0077] in, are the d-axis and q-axis positive sequence control voltages of the grid-side converter respectively; are the d-axis and q-axis negative sequence control voltages of the grid-side converter respectively; are the d-axis and q-axis positive sequence currents on the grid side respectively; are the d-axis and q-axis negative sequence currents on the grid side respectively; are the d-axis and q-axis positive sequence voltages on the grid side respectively; They are the d and q axis negative sequence voltages on the grid side respectively.

[0078] Furthermore, the d-axis and q-axis positive sequence control voltages and the d-axis and q-axis negative sequence control voltages are used to perform closed-loop control on the positive and negative sequence dq-axis components of the grid-side converter respectively.

[0079] In practical applications, such as Figure 3 As shown, the above equations (4) and (5) are transformed into control strategies as shown in equations (6) and (7):

[0080]

[0081] Among them, k p1 , k p2 They are respectively the positive and negative sequence voltage PI regulation proportional coefficients, k i1 , k i2 They are the integral time constants of the positive and negative sequence voltage PI regulators respectively.

[0082] In some other embodiments, when the working state is a voltage surge state, the corresponding control rule is based on the principle that the reactive current value can be controlled solely by the q-axis current after decoupling, and the reference value of the reactive outer loop is calculated using the effective value of the AC side voltage to perform reactive compensation on the power grid, and the energy imbalance problem on both sides of the DC bus is solved by the DC side unloading resistor.

[0083] Specifically, this embodiment can calculate the grid-side reactive power reference value based on the nominal value of the grid connection point rated voltage, the nominal value of the actual grid connection point voltage, and the rated current of the grid connection point.

[0084] In some embodiments, the grid-side reactive power reference value is calculated according to the following formula (8):

[0085]

[0086] Among them, Q * is the grid-side reactive power reference value; E is the nominal value of the grid-connected point rated voltage; g is the nominal value of the actual voltage at the grid connection point; I n is the rated current of the grid-connected point; β is the proportional coefficient of the q-axis current value, which is β≥1.5 according to the relevant requirements of the wind farm, and the specific value is obtained through debugging based on the actual situation.

[0087] Furthermore, the grid-side converter is controlled based on the grid-side reactive power reference value to perform reactive power compensation on the grid.

[0088] In an embodiment of the present disclosure, target information on the grid side of a permanent magnet direct-drive wind turbine grid-connected system is obtained, wherein the target information includes at least current information and voltage information, and a working state of the grid side is determined based on the target information, wherein the working state is divided into a normal state, a short circuit fault state, and a voltage surge state, and a control rule corresponding to the working state is used to control the grid-side converter of the permanent magnet direct-drive wind turbine grid-connected system. Different control methods can be used to control the grid-side converter in different working states such as a normal state, a short circuit fault state, and a voltage surge state on the grid side, thereby improving the grid-connected stability of the wind power system.

[0089] The machine-side converter control method and the grid-side converter control method proposed in this embodiment can effectively perform low voltage ride-through for various symmetrical and asymmetrical faults on the grid side. At the same time, reactive power can be injected into the grid side during high and low voltage ride-through to help fault recovery; when the grid-side frequency changes, energy is stored in the generator rotor in the form of kinetic energy, which greatly reduces active power loss; the machine-side and grid-side converters do not require an obvious switching control method process, and the disturbance to the control quantity is smaller.

[0090] In order to implement the above embodiments, the present disclosure also proposes a permanent magnet direct-drive wind turbine side converter control device.

[0091] Figure 3 It is a schematic diagram of a permanent magnet direct-drive wind turbine side converter control device provided according to another embodiment of the present disclosure.

[0092] like Figure 3 As shown, the permanent magnet direct-drive wind turbine side converter control device 40 comprises:

[0093] An acquisition module 301 is used to acquire frequency change information of the grid side of the permanent magnet direct-drive wind turbine grid-connected system;

[0094] A determination module 302 is used to determine the working state of the power grid side based on the frequency change information, wherein the working state is divided into a normal state and a frequency change state; and

[0095] The control module 303 is used to control the machine-side converter of the permanent magnet direct-drive wind turbine grid-connected system by using a control rule corresponding to the working state.

[0096] In some embodiments, when the working state is normal, the control module 303 is specifically used to: in response to the current wind speed being greater than the cut-in wind speed and less than the rated wind speed, calculate the current maximum power of the permanent magnet direct-drive generator based on the current air density, the generator electrical angular velocity, the wind wheel radius, the maximum wind energy utilization coefficient, the optimal tip speed ratio, and the local power coefficient, and calculate the maximum torque based on the maximum power; and calculate the difference between the maximum torque and the current torque of the permanent magnet direct-drive generator as the input of the active current loop of the machine-side converter.

[0097] In some embodiments, the current maximum power of the permanent magnet direct-drive generator is calculated according to the following formula:

[0098]

[0099] Among them, P opt is the current maximum power; ρ is the current air density; ω s is the electrical angular velocity of the generator; R is the radius of the wind wheel; C Pmax is the maximum wind energy utilization coefficient; optis the optimal tip speed ratio; G is the local power coefficient.

[0100] In some embodiments, the control module 303 is further configured to: limit the maximum torque in response to the current wind speed being greater than the rated wind speed and less than the cut-out wind speed.

[0101] In some embodiments, when the working state is a frequency change state, the control module 303 is specifically used to: calculate the current maximum power of the permanent magnet direct-drive generator based on the current air density, the electrical angular velocity of the generator, the radius of the wind wheel, the maximum wind energy utilization coefficient, the optimal tip speed ratio, and the local power coefficient, and calculate the maximum torque based on the maximum power; calculate the auxiliary torque based on the system frequency deviation on the grid side; and determine the q-axis reference current based on the sum of the maximum torque and the auxiliary torque as the input of the outer loop control of the machine-side converter torque.

[0102] In some embodiments, the assist torque is calculated according to the following formula:

[0103]

[0104] Among them, P vir is the auxiliary torque, Δf is the system frequency deviation; k p and k d are the proportional coefficient and the differential coefficient respectively.

[0105] In some embodiments, the q-axis reference current is determined according to the following formula:

[0106]

[0107] in, represents the q-axis reference current, P MPPT represents the maximum torque, ω s represents the electrical angular velocity of the generator, p n represents the number of pole pairs of the permanent magnet direct drive generator, ψ f Represents the rotor flux.

[0108] In this embodiment, the frequency change information of the grid side of the permanent magnet direct-drive wind turbine grid-connected system is obtained, and the working state of the grid side is determined based on the frequency change information, wherein the working state is divided into a normal state and a frequency change state, and the control rules corresponding to the working state are used to control the machine-side converter of the permanent magnet direct-drive wind turbine grid-connected system. Different control methods can be used to control the machine-side converter in different working states such as the normal state and the frequency change state of the grid side, thereby improving the frequency support capability of the wind power system.

[0109] According to an embodiment of the present disclosure, the present disclosure also provides an electronic device, a readable storage medium and a computer program product.

[0110] In order to implement the above embodiments, the present disclosure further proposes a computer program product. When the instruction processor in the computer program product is executed, the permanent magnet direct-drive wind turbine side converter control method proposed in the above embodiments of the present disclosure is executed.

[0111] Figure 4 A block diagram of an exemplary electronic device suitable for implementing embodiments of the present disclosure is shown. Figure 4 The electronic device 12 shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present disclosure.

[0112] like Figure 4 As shown, the electronic device 12 is in the form of a general purpose computing device. The components of the electronic device 12 may include, but are not limited to: one or more processors or processing units 16, a system memory 28, and a bus 18 that connects various system components (including the system memory 28 and the processing unit 16).

[0113] The bus 18 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration port, a processor or a local bus using any of a variety of bus structures. For example, these architectures include but are not limited to Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MAC) bus, Enhanced ISA bus, Video Electronics Standards Association (VESA) local bus and Peripheral Component Interconnection (PCI) bus.

[0114] The electronic device 12 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by the electronic device 12, including volatile and non-volatile media, removable and non-removable media.

[0115] The memory 28 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and / or cache memory 32. The electronic device 12 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, the storage system 34 may be used to read and write non-removable, non-volatile magnetic media ( Figure 4Not shown, often called a "hard drive").

[0116] although Figure 4 Not shown in the figure, a disk drive for reading and writing a removable non-volatile disk (e.g., a "floppy disk"), and an optical disk drive for reading and writing a removable non-volatile optical disk (e.g., a compact disc read only memory (CD-ROM), a digital versatile disc read only memory (DVD-ROM), or other optical media) may be provided. In these cases, each drive may be connected to the bus 18 via one or more data medium interfaces. The memory 28 may include at least one program product having a set (e.g., at least one) of program modules configured to perform the functions of the various embodiments of the present disclosure.

[0117] A program / utility 40 having a set (at least one) of program modules 42 may be stored, for example, in the memory 28, such program modules 42 including but not limited to an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment. The program modules 42 generally perform the functions and / or methods of the embodiments described in the present disclosure.

[0118] The electronic device 12 may also communicate with one or more external devices 14 (e.g., keyboards, pointing devices, displays 24, etc.), may also communicate with one or more devices that enable a user to interact with the electronic device 12, and / or may communicate with any device that enables the electronic device 12 to communicate with one or more other computing devices (e.g., network cards, modems, etc.). Such communication may be performed via an input / output (I / O) interface 22. Furthermore, the electronic device 12 may also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) via a network adapter 20. As shown, the network adapter 20 communicates with other modules of the electronic device 12 via a bus 18. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with the electronic device 12, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0119] The processing unit 16 executes various functional applications by running the programs stored in the system memory 28, such as implementing the permanent magnet direct-drive wind turbine side converter control method mentioned in the above-mentioned embodiment.

[0120] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. The present disclosure is intended to cover any variations, uses or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The description and examples are to be considered exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

[0121] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

[0122] It should be noted that, in the description of the present disclosure, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present disclosure, unless otherwise specified, the meaning of "plurality" is two or more.

[0123] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present disclosure includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present disclosure belong.

[0124] It should be understood that the various parts of the present disclosure can be implemented in hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0125] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0126] In addition, each functional unit in each embodiment of the present disclosure may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0127] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0128] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0129] Although the embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present disclosure. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present disclosure.

Claims

1. A method for controlling a permanent magnet direct-drive wind turbine side converter, characterized in that: The method comprises: Obtain frequency change information on the grid side of the permanent magnet direct-drive wind turbine grid-connected system; Determining the grid-side working state based on the frequency change information, wherein the working state is divided into a normal state and a frequency change state; and The machine-side converter of the permanent magnet direct-drive wind turbine grid-connected system is controlled by using a control rule corresponding to the working state.

2. The method according to claim 1, characterized in that When the working state is the normal state, controlling the machine-side converter of the permanent magnet direct-drive wind turbine grid-connected system by using a control rule corresponding to the working state includes: In response to the current wind speed being greater than the cut-in wind speed and less than the rated wind speed, based on the current air density, the electrical angular velocity of the generator, the radius of the wind rotor, the maximum wind energy utilization coefficient, the optimal tip speed ratio, and the local power coefficient, the current maximum power of the permanent magnet direct-drive generator is calculated, and the maximum torque is calculated based on the maximum power; and The difference between the maximum torque and the current torque of the permanent magnet direct-drive generator is calculated as the input of the active current loop of the machine-side converter.

3. The method according to claim 2, characterized in that in, The current maximum power of the permanent magnet direct drive generator is calculated according to the following formula: Among them, P opt is the current maximum power; ρ is the current air density; ω s is the electrical angular velocity of the generator; R is the radius of the wind wheel; C Pmax is the maximum wind energy utilization coefficient; opt is the optimal tip speed ratio; G is the local power coefficient.

4. The method according to claim 2, characterized in that The method includes limiting the maximum torque in response to a current wind speed being greater than a rated wind speed and less than a cut-out wind speed.

5. The method according to claim 1, characterized in that When the working state is the frequency change state, controlling the machine-side converter of the permanent magnet direct-drive wind turbine grid-connected system by using a control rule corresponding to the working state includes: Based on the current air density, the electrical angular velocity of the generator, the radius of the wind wheel, the maximum wind energy utilization coefficient, the optimal tip speed ratio, and the local power coefficient, the current maximum power of the permanent magnet direct-drive generator is calculated, and the maximum torque is calculated based on the maximum power; Calculating auxiliary torque based on system frequency deviation on the grid side; and A q-axis reference current is determined based on the sum of the maximum torque and the auxiliary torque to serve as an input of the torque outer loop control of the generator-side converter.

6. The method according to claim 5, characterized in that in, The assist torque is calculated according to the following formula: Among them, P vir is the auxiliary torque, Δf is the system frequency deviation; k p and k d are the proportional coefficient and the differential coefficient respectively.

7. The method according to claim 6, characterized in that in, The q-axis reference current is determined according to the following formula: in, represents the q-axis reference current, P MPPT represents the maximum torque, ω s represents the electrical angular velocity of the generator, p n represents the number of pole pairs of the permanent magnet direct drive generator, ψ f Represents the rotor flux.

8. A permanent magnet direct drive wind turbine side converter control device, characterized in that: include: An acquisition module is used to acquire frequency change information on the grid side of a permanent magnet direct-drive wind turbine grid-connected system; A determination module, configured to determine the grid-side working state based on the frequency change information, wherein the working state is divided into a normal state and a frequency change state; as well as A control module is used to control the machine-side converter of the permanent magnet direct-drive wind turbine grid-connected system by using a control rule corresponding to the working state.

9. The device according to claim 8, characterized in that When the working state is the normal state, the control module is specifically used to: In response to the current wind speed being greater than the cut-in wind speed and less than the rated wind speed, based on the current air density, the electrical angular velocity of the generator, the radius of the wind wheel, the maximum wind energy utilization coefficient, the optimal tip speed ratio, and the local power coefficient, the current maximum power of the permanent magnet direct-drive generator is calculated, and the maximum torque is calculated based on the maximum power; as well as The difference between the maximum torque and the current torque of the permanent magnet direct-drive generator is calculated as the input of the active current loop of the machine-side converter.

10. A non-transitory computer-readable storage medium storing computer instructions, wherein: The computer instructions are used to cause the computer to execute the method according to any one of claims 1-7.

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