CN117200313A - Control method of wind generating set and wind generating set - Google Patents

Control method of wind generating set and wind generating set Download PDF

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Publication number
CN117200313A
CN117200313A CN202210610391.3A CN202210610391A CN117200313A CN 117200313 A CN117200313 A CN 117200313A CN 202210610391 A CN202210610391 A CN 202210610391A CN 117200313 A CN117200313 A CN 117200313A
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CN
China
Prior art keywords
reference value
energy storage
grid
power
storage device
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Pending
Application number
CN202210610391.3A
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Chinese (zh)
Inventor
曹晓东
刘世军
俞黎萍
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Jinfeng Technology Co ltd
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Jinfeng Technology Co ltd
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Priority to CN202210610391.3A priority Critical patent/CN117200313A/en
Priority to PCT/CN2022/122231 priority patent/WO2023231252A1/en
Publication of CN117200313A publication Critical patent/CN117200313A/en
Pending legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/28—Arrangements for balancing of the load in a network by storage of energy
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/28—Arrangements for balancing of the load in a network by storage of energy
    • H02J3/30—Arrangements for balancing of the load in a network by storage of energy using dynamo-electric machines coupled to flywheels
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
    • H02J3/48—Controlling the sharing of the in-phase component
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
    • H02J3/50—Controlling the sharing of the out-of-phase component

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Control Of Eletrric Generators (AREA)

Abstract

The disclosure provides a control method of a wind generating set and the wind generating set, wherein the control method comprises the following steps: determining an active current reference value of the energy storage device based on the direct current bus voltage reference value and the obtained direct current bus voltage; determining a reactive current reference value of the energy storage device based on the energy storage device voltage reference value and the obtained energy storage device voltage; determining a quadrature axis voltage reference value and a direct axis voltage reference value of the energy storage device based on the active current reference value and the reactive current reference value of the energy storage device and the obtained active current and reactive current of the energy storage device; and controlling the charging or discharging of the energy storage device based on the quadrature axis voltage reference value and the direct axis voltage reference value so as to control the direct current bus voltage. According to the control method of the wind generating set and the wind generating set, the problem that the controllability of the set cannot be improved is solved, and balance control of power of a fan converter side and a grid side can be unbinding, so that the high controllability of grid-connected power of the set is improved.

Description

Control method of wind generating set and wind generating set
Technical Field
The disclosure relates to the technical field of wind power generation, and more particularly, to a control method of a wind generating set and the wind generating set.
Background
With the development of wind power generation technology, the structure and corresponding control flow of the wind generating set are more and more complex, and besides the basic control mode, related control functions such as active support and the like are required to be realized.
In the existing control scheme, under the condition of normal operation of the unit, the control of the direct current bus can be realized through a fan converter of the unit. However, because the fan converter is bound with the control of the direct current bus, other control processes cannot be realized, such as decoupling control on the machine side power and the network side power, and the like, so that the controllability of the unit cannot be improved.
Disclosure of Invention
In view of the problem that the controllability of the unit cannot be improved in the existing control scheme, the disclosure provides a control method of a wind turbine generator and the wind turbine generator.
A first aspect of the present disclosure provides a control method of a wind power generation set including a fan converter and an energy storage device connected to a dc bus of the fan converter, the control method comprising: determining an active current reference value of the energy storage device based on a preset direct current bus voltage reference value and the obtained direct current bus voltage; determining a reactive current reference value of the energy storage device based on a preset energy storage device voltage reference value and the acquired energy storage device voltage; determining a quadrature axis voltage reference value and a direct axis voltage reference value of the energy storage device based on the active current reference value and the reactive current reference value of the energy storage device and the obtained active current and reactive current of the energy storage device; and controlling the energy storage device to charge or discharge based on the quadrature axis voltage reference value and the direct axis voltage reference value so as to control the direct current bus voltage.
Optionally, the step of determining the reactive current reference value of the energy storage device comprises: if the voltage of the energy storage device is smaller than the voltage reference value of the energy storage device, the reactive current reference value of the energy storage device is 0; and if the voltage of the energy storage device is greater than or equal to the voltage reference value of the energy storage device, determining a reactive current reference value of the energy storage device based on a difference value between the voltage of the energy storage device and the voltage reference value of the energy storage device.
Optionally, the fan converter includes a grid-side converter, wherein the control method further includes: determining a direct-axis current reference value of the network-side converter based on a preset network-side active power reference value and the acquired network-side active power; determining a quadrature axis current reference value of the network side converter based on a preset network side reactive power reference value and the acquired network side reactive power; and controlling the grid-side converter based on the direct-axis current reference value, the quadrature-axis current reference value and the acquired grid-side three-phase voltage and grid-side three-phase current so as to control the grid-side active power and the grid-side reactive power.
Optionally, the fan converter includes a grid-side converter, wherein the control method further includes: determining a grid phase angle reference value of the grid-side converter based on a preset grid-side active power reference value, a grid rated angular speed and the obtained grid-side active power and grid angular speed; determining a network side voltage amplitude reference value of the network side converter based on a preset network side reactive power reference value and the acquired network side reactive power; and controlling the grid-side converter based on the grid phase angle reference value and the grid-side voltage amplitude reference value.
Optionally, the fan converter includes a machine side converter, wherein the control method further includes: determining an output active current reference value of a generator of the wind generating set based on a preset maximum active power and the obtained output active power of the generator; determining an output reactive current reference value of the generator based on a preset generator voltage reference value and the acquired generator voltage; determining a quadrature axis voltage reference value and a direct axis voltage reference value of the generator based on the output active current reference value, the output reactive current reference value and the obtained active current and reactive current of the generator; and controlling the machine side converter based on the quadrature axis voltage reference value and the direct axis voltage reference value of the generator to control the output active power of the generator.
Optionally, the network side active power reference value and the network side reactive power reference value are determined by: and responding to the high-voltage fault or the low-voltage fault of the wind generating set, and determining the network side active power reference value and the network side reactive power reference value according to the preset apparent power.
Optionally, the network side active power reference value is determined by: acquiring a network side active power reference value and inertia response power of the wind generating set before inertia response; determining a network side active power reference value of the wind generating set after inertia response based on the network side active power reference value before inertia response and the inertia response power; or acquiring a network side active power reference value and primary frequency modulation power of the wind generating set before primary frequency modulation; determining a network side active power reference value of the wind generating set after primary frequency modulation based on the network side active power reference value before primary frequency modulation and the primary frequency modulation power; or acquiring a network side active power instruction value and a current grid-connected active power instruction value of the wind generating set; and determining the network side active power reference value based on the network side active power instruction value and the current grid-connected active power instruction value of the unit.
A second aspect of the present disclosure provides a computer device comprising a processor and a memory: the memory is used for storing program codes and transmitting the program codes to the processor; the processor is used for executing the control method of the wind generating set according to the disclosure according to the instructions in the program code.
Optionally, the computer device is connected to a controller of the energy storage device, a controller of a converter in the wind power generation set, or a main controller of the wind power generation set; alternatively, the computer device is arranged in a controller of the energy storage device or a controller of a converter in the wind generating set.
A third aspect of the present disclosure provides a wind power plant comprising a control device of a wind power plant according to the present disclosure or a computer arrangement according to the present disclosure.
Optionally, the wind generating set is a direct-drive wind generating set, a semi-direct-drive wind generating set or a doubly-fed wind generating set.
According to the control method of the wind generating set and the wind generating set, the energy storage device can be connected to the direct current bus of the fan converter to allow the direct current bus voltage to be controlled by controlling the charging or discharging of the energy storage device, so that the control of the fan converter and the direct current bus can be unbinding, other control processes can be realized by using the fan converter, and the controllability of the wind generating set is improved.
Drawings
Fig. 1 is a schematic block diagram showing an example of a fan converter of an existing wind turbine generator system.
Fig. 2 is a schematic block diagram illustrating a wind turbine converter and an energy storage device of a wind turbine generator set according to an exemplary embodiment of the present disclosure.
Fig. 3 is a schematic block diagram illustrating a fan converter and flywheel energy storage unit according to an exemplary embodiment of the present disclosure.
Fig. 4 is a schematic diagram illustrating the overall architecture of a flywheel energy storage system including a flywheel energy storage unit according to an exemplary embodiment of the present disclosure.
Fig. 5 is a schematic flow chart illustrating a control method of a wind turbine generator set according to an exemplary embodiment of the present disclosure.
Fig. 6 is a schematic diagram illustrating control of a flywheel energy storage converter of a wind turbine generator set according to an exemplary embodiment of the present disclosure.
Fig. 7 is a schematic flow chart illustrating a first example of control of a grid-side converter in a control method of a wind turbine generator system according to an exemplary embodiment of the present disclosure.
Fig. 8 is a schematic diagram illustrating a first example of control of a grid-side converter of a wind turbine generator system according to an exemplary embodiment of the present disclosure.
Fig. 9 is a schematic flow chart illustrating a second example of control of a grid-side converter in a control method of a wind turbine generator system according to an exemplary embodiment of the present disclosure.
Fig. 10 is a schematic diagram illustrating a second example of control of a grid-side converter of a wind turbine generator system according to an exemplary embodiment of the present disclosure.
Fig. 11 is a schematic flow chart illustrating control of a machine side converter of a wind turbine generator set according to an exemplary embodiment of the present disclosure.
Fig. 12 is a schematic diagram illustrating control of a machine side converter of a wind turbine generator set according to an exemplary embodiment of the present disclosure.
Fig. 13 is a schematic diagram illustrating an example of a wind power generation set according to an exemplary embodiment of the present disclosure.
Reference numerals:
1000: flywheel energy storage system, 1001: system controller, 1002: auxiliary device, 100: generator unit, 200: fan converter, 210: side converter, 211: first filter, 212: first bridge circuit module, 220: network-side converter, 221: second filter, 222: second bridge circuit module, 230: braking unit, 240: discharge unit, 300: energy storage device, 310: flywheel energy storage unit, 320: flywheel motor current transformer, 321: flywheel filter, 322: flywheel bridge circuit module, 330: flywheel energy storage converter, 400: ac grid, 410: first grid, 420: and a second power grid.
Detailed Description
The following detailed description is provided to assist the reader in obtaining a thorough understanding of the methods, apparatus, and/or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and/or systems described herein will be apparent after an understanding of the present disclosure. For example, the order of operations described herein is merely an example and is not limited to those set forth herein, but may be altered as will be apparent after an understanding of the disclosure of the application, except for operations that must occur in a specific order. Furthermore, descriptions of features known in the art may be omitted for clarity and conciseness.
The features described herein may be embodied in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein have been provided to illustrate only some of the many possible ways to implement the methods, devices, and/or systems described herein that will be apparent after an understanding of the present disclosure.
As used herein, the term "and/or" includes any one of the listed items associated as well as any combination of any two or more.
Although terms such as "first," "second," and "third" may be used herein to describe various elements, components, regions, layers or sections, these elements, components, regions, layers or sections should not be limited by these terms. Rather, these terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first member, first component, first region, first layer, or first portion referred to in the examples described herein may also be referred to as a second member, second component, second region, second layer, or second portion without departing from the teachings of the examples.
In the description, when an element (such as a layer, region or substrate) is referred to as being "on" another element, "connected to" or "coupled to" the other element, it can be directly "on" the other element, be directly "connected to" or be "coupled to" the other element, or one or more other elements intervening elements may be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" or "directly coupled to" another element, there may be no other element intervening elements present.
The terminology used herein is for the purpose of describing various examples only and is not intended to be limiting of the disclosure. Singular forms also are intended to include plural forms unless the context clearly indicates otherwise. The terms "comprises," "comprising," and "having" specify the presence of stated features, amounts, operations, components, elements, and/or combinations thereof, but do not preclude the presence or addition of one or more other features, amounts, operations, components, elements, and/or combinations thereof.
Unless defined otherwise, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs after understanding this disclosure. Unless explicitly so defined herein, terms (such as those defined in a general dictionary) should be construed to have meanings consistent with their meanings in the context of the relevant art and the present disclosure, and should not be interpreted idealized or overly formal.
In addition, in the description of the examples, when it is considered that detailed descriptions of well-known related structures or functions will cause a ambiguous explanation of the present disclosure, such detailed descriptions will be omitted.
Fig. 1 shows a schematic block diagram of an example of a fan converter of a prior art wind power plant.
As shown in fig. 1, the wind power generation set includes a generator unit 100 and a wind power converter 200.
The generator unit 100 may include a fan impeller and a generator G, an ac port of which is connected to an ac port of the fan converter 200 to be able to supply power to the fan converter 200.
Fan converter 200 may include a machine side converter 210 and a grid side converter 220. As an example, the ac side of the machine side converter 210 may be connected to an ac port of the generator G, the dc side of the machine side converter 210 may be connected to the dc side of the grid side converter 220, and the ac side of the grid side converter 220 may be connected to the ac grid 400.
The fan converter 200 may further include a braking unit 230 and a discharging unit 240, where the braking unit 230 may consume excessive power when the wind turbine is in high voltage/low voltage fault ride through, so as to avoid damage to electrical devices, and the discharging unit 240 may release the electrical energy of the dc bus supporting capacitor when the wind turbine is stopped.
For such a wind power generation set, under normal operation of the set, control of the dc bus may be achieved by the fan converter 200 of the set. However, since the fan converter 200 is bound to the control of the dc bus, it cannot implement other control processes, and thus the controllability of the unit cannot be improved.
Specifically, decoupling control cannot be achieved by the machine side power and the network side power, and high controllability of the grid-connected power of the machine set cannot be achieved under the condition that maximum wind power tracking of the machine set is not changed due to balance of the machine side active power and the network side active power under normal operation of the machine set.
In addition, in the current control mode, the maximum wind power tracking of the machine side, the balance control of the machine side power and the network side power cause synchronization sub-synchronous harmonic waves. In addition, because the voltage of the grid-side control direct current bus is stable, grid-connected current harmonic waves are large, and the grid-connected power quality is affected.
In addition, in the current control mode, under the high voltage/low voltage fault ride through condition, a brake unit (such as the brake unit 230 shown in fig. 1) is generally started to assist in dc bus voltage control, so that on one hand, stability of network side active power and reactive power control is affected, and on the other hand, problems in terms of applicability of high voltage/low voltage ride through functions are caused, and on the other hand, electric energy waste is caused.
In addition, based on the current control mode, the realization of active support functions such as unit inertia response and primary frequency modulation is complex, and the restriction of the balance of the machine side power and the network side power cannot be removed.
In addition, grid-connected power at the grid side completely depends on the magnitude of wind energy at the grid side, so that the grid-connected power cannot be stably output when the wind speed changes.
In addition, based on the current control mode, free switching of off-grid/grid-connected control cannot be achieved.
In addition, under weak grid conditions (SCR < 2), the current control mode is poorly adapted, resulting in a larger grid-tie pressure.
In addition, based on the current control mode, the free switching challenges of the network side voltage source control and the current source control mode are larger under weak current network adaptability.
In view of this, exemplary embodiments according to the present disclosure provide a control method of a wind power generation set, a control device of a wind power generation set, a computer device, and a wind power generation set to solve at least one of the above problems.
According to a first aspect of the present disclosure, a control method of a wind power plant is provided.
An exemplary structure of a fan converter and an energy storage device according to an exemplary embodiment of the present disclosure will be described below with reference to fig. 2.
Fig. 2 is a schematic block diagram illustrating a wind turbine converter and an energy storage device of a wind turbine generator set according to an exemplary embodiment of the present disclosure.
As shown in fig. 2, the wind power generation set may include a generator unit 100, a fan converter 200, and an energy storage device 300.
The generator unit 100 may include a fan impeller and a generator, an ac port of which is connected to an ac port of the fan converter 200 to be able to supply power to the fan converter 200.
Fan converter 200 may include a machine side converter 210 and a grid side converter 220. As an example, the ac side of the machine side converter 210 may be connected to an ac port of the generator, the dc side of the machine side converter 210 may be connected to the dc side of the grid side converter 220, and the ac side of the grid side converter 220 may be connected to the ac grid 400.
In an exemplary embodiment according to the present disclosure, the machine side converter 210 and the grid side converter 220 may be bi-directional ac-dc converters. The machine side converter 210 and the grid side converter 220 may have the same structure, and during the current transformation, the machine side converter 210 and the grid side converter 220 perform opposite current transformation functions, for example, as shown in fig. 2, the machine side converter 210 may convert ac power from the generator into dc power, and the grid side converter 220 may convert the dc power into ac power and provide the ac power to the ac power grid.
In addition, as shown in fig. 2, the fan converter 200 may further include a braking unit 230 and a discharging unit 240 connected between the machine side converter 210 and the grid side converter 220, however, it is not limited thereto, and the fan converter 200 according to an exemplary embodiment of the present disclosure may also not include the braking unit 230 and the discharging unit 240, but regulate the dc bus voltage only through the energy storage device 300, which will be described in detail below.
The energy storage device 300 may be connected to the dc side of the fan converter 200. As shown in fig. 2, the energy storage device 300 may be connected to a dc bus of the fan converter 200, in particular, between the machine side converter 210 and the grid side converter 220.
The energy storage device 300 may be an energy storage device or system having charge and discharge functions, and such an energy storage device or system may include devices such as a chargeable and dischargeable battery, a super capacitor, or the like, but is not limited thereto, and may be a flywheel energy storage unit, for example, as will be described in detail in the examples of fig. 3 and 4.
By connecting the energy storage device 300 to the dc bus of the fan converter 200, the dc bus voltage may be controlled by controlling the charging or discharging of the energy storage device, a specific control process of which will be described in detail below with reference to fig. 5.
As an example, the energy storage device 300 may be a flywheel energy storage unit, and the structure of the fan converter and the flywheel energy storage unit will be described in detail with reference to fig. 3 and 4.
Fig. 3 illustrates an example in which the energy storage device is a flywheel energy storage unit according to an exemplary embodiment of the present disclosure.
As shown in fig. 3, the machine side converter 210 may include a first filter 211 and a first bridge circuit module 212, and the net side converter 220 may include a second filter 221 and a second bridge circuit module 222.
The first filter 211 and the second filter 221 may have the same or similar structure, for example, may each be an inductance, but specific parameters of the two may be the same or different.
The first bridge circuit module 212 and the second bridge circuit module 222 may have the same or similar structure, and may be a three-phase bridge circuit, such as a two-level three-phase bridge circuit and a five-level three-phase bridge circuit, but it should be understood that three-phase bridge circuits of other topologies, such as a three-level three-phase bridge circuit, may also be used, and the specific structure of the bridge circuits is not particularly limited by the present disclosure.
The fan converter 200 may further include a first capacitor C1, where the first capacitor C1 may be used as a dc bus supporting voltage, and the first capacitor C1 may be connected between a dc positive bus and a dc negative bus of the machine side converter 210 and the grid side converter 220, where the first capacitor C1 may be replaced by two or more capacitors.
The flywheel energy storage unit 310 in fig. 3 may be connected to the wind turbine converter 200 of the wind power plant. Specifically, the flywheel energy storage unit 310 may be connected to a dc bus of the fan converter 200.
As shown in fig. 3, the flywheel energy storage unit 310 may be connected between the machine side converter 210 and the grid side converter 220 of the fan converter 200.
In addition, a flywheel motor converter 320 may be connected between the flywheel energy storage unit 310 and the dc bus of the fan converter 200. The ac side of the flywheel energy storage unit 310 is connected to the ac side of the flywheel motor converter 320 and the dc side of the flywheel motor converter 320 is connected to the dc bus of the fan converter 200.
The flywheel motor converter 320 may control the rotation speed of the flywheel motor in the flywheel energy storage unit 310, and when the rotation speed of the flywheel motor increases, the flywheel energy storage unit 310 is charged, that is, the electric energy is converted into the rotational kinetic energy of the flywheel; when the rotation speed of the flywheel motor is reduced, the flywheel energy storage unit 310 is discharged, that is, the rotational kinetic energy of the flywheel is converted into electric energy.
As shown in fig. 3, the flywheel motor converter 320 may include a flywheel filter 321 and a flywheel bridge circuit module 322. The flywheel filter 321 may have the same or similar structure as the first filter 211 and the second filter 221 described above, for example, may be an inductor, but specific parameters of the three may be the same or different.
The flywheel bridge circuit module 322 may have the same or similar structure as the first bridge circuit module 212 and the second bridge circuit module 222 described above, and may also be a three-phase bridge circuit, such as a two-level three-phase bridge circuit and a five-level three-phase bridge circuit, but it should be understood that three-phase bridge circuits of other topologies may also be used, such as a three-level three-phase bridge circuit, and the specific structure of the bridge circuit is not particularly limited by the present disclosure.
Further, a second capacitor C2 may be connected between the dc positive bus and the dc negative bus of the flywheel motor converter 320, and the second capacitor C2 may be used as a dc bus support voltage, where the second capacitor C2 may be replaced by two or more capacitors.
Fig. 4 is a schematic diagram illustrating the overall architecture of a flywheel energy storage system including a flywheel energy storage unit according to an exemplary embodiment of the present disclosure.
The flywheel energy storage system (flywheel energy storage system) is an energy storage device for realizing the bidirectional conversion of electric energy and kinetic energy.
In the example of fig. 4, the flywheel energy storage system 1000 may include a system controller 1001, a flywheel energy storage unit 310, a flywheel motor converter 320, a flywheel energy storage converter 330, and an auxiliary device 1002. Here, the flywheel energy storage unit 310 (flywheel energy storage unit) may be an electromechanical structural component of a flywheel energy storage system that is composed of a flywheel rotor, a flywheel motor, bearings, a sealed housing, and the like. Flywheel motor inverter 320 (flywheel converter) may be a power electronic power device that performs rotational speed and power control of flywheel motor operation, directly or indirectly effecting bi-directional transfer of direct current electrical energy (from a power source or load) and flywheel energy. Flywheel energy storage converter 330 (power converter) may be an electronic power device that enables bi-directional energy transfer between the flywheel energy storage system dc bus and the ac power grid (and/or load).
Fig. 5 is a schematic flow chart illustrating a control method of a wind turbine generator set according to an exemplary embodiment of the present disclosure.
As shown in fig. 5, the control method of the wind turbine generator set may include the steps of:
in step S51, an active current reference value of the energy storage device may be determined based on the preset dc bus voltage reference value and the obtained dc bus voltage.
Here, the dc bus voltage reference value may be arbitrarily set according to actual needs, and may be used as a control target value for the dc bus. The DC bus voltage can be acquired through real-time acquisition.
In this step, an error between the preset dc bus voltage reference value and the currently acquired dc bus voltage may be determined by comparing the two values, and the error may be input to the controller, thereby determining an active current reference value for controlling the energy storage device. Here, the controller is, for example, but not limited to, a proportional-integral controller.
In step S52, a reactive current reference value of the energy storage device may be determined based on the preset energy storage device voltage reference value and the obtained energy storage device voltage.
Here, the voltage reference value of the energy storage device may be set arbitrarily according to actual needs, for example, it may be a maximum voltage value of the energy storage device, and during the control of the energy storage device, the voltage of the energy storage device may be controlled not to exceed the voltage reference value of the energy storage device. The energy storage device voltage can be acquired through real-time acquisition.
In this step, if the energy storage device voltage is less than the energy storage device voltage reference value, the reactive current reference value of the energy storage device may be determined to be 0; if the energy storage device voltage is greater than or equal to the energy storage device voltage reference value, a reactive current reference value of the energy storage device may be determined based on a difference between the energy storage device voltage and the energy storage device voltage reference value.
Specifically, the difference between the preset energy storage device voltage reference value and the currently acquired energy storage device voltage may be determined by comparing the two values, and the difference may be input into the controller, thereby determining the reactive current reference value for controlling the energy storage device. Here, the controller is, for example, but not limited to, a proportional-integral controller.
As an example, in case the energy storage device is a flywheel energy storage unit, the energy storage device voltage reference value may be a weak magnetic loop control line voltage reference value of the flywheel energy storage unit, and the energy storage device voltage may be a flywheel motor line voltage.
In step S53, a quadrature axis voltage reference value and a direct axis voltage reference value of the energy storage device may be determined based on the active current reference value and the reactive current reference value of the energy storage device and the obtained active current and reactive current of the energy storage device.
Here, the active current and the reactive current of the energy storage device may be acquired through real-time acquisition, or may be determined by converting three-phase current of the energy storage device into two-phase current in a rotating coordinate system through coordinate system conversion (e.g., clarke transformation process).
As an example, in case the energy storage device is a flywheel energy storage unit, the active current and the reactive current of the flywheel energy storage unit may be determined based on the rotor angle of the flywheel energy storage unit and the three-phase current of the flywheel motor.
In particular, the rotor angle of the flywheel energy storage unit and the three-phase current of the flywheel motor may be collected, such that the three-phase current of the flywheel motor may be converted into two-phase currents in a rotational coordinate system, i.e. the active current and the reactive current of the flywheel motor, based on the rotor angle, e.g. by a Clarke transformation procedure.
Under the condition that the active current reference value and the reactive current reference value of the energy storage device and the active current and the reactive current of the energy storage device are determined, the active current reference value and the reactive current reference value of the energy storage device can be used as target values of current control of the energy storage device through voltage outer loop control and current inner loop control, so that the quadrature axis voltage reference value and the direct axis voltage reference value of the energy storage device are determined. Here, the intersecting axis and the straight axis may correspond to two coordinate axes in a rotational coordinate system, for example, a q-axis and a d-axis, respectively.
In step S54, the energy storage device may be controlled to charge or discharge based on the quadrature axis voltage reference value and the direct axis voltage reference value to control the direct current bus voltage.
In this step, the quadrature axis voltage reference value and the direct axis voltage reference value may be converted into three-phase voltage reference values of the energy storage device by an inverse transformation (e.g., clarke inverse transformation process) to the coordinate system transformation described above.
The control of the dc bus voltage can be achieved by controlling the charging or discharging of the energy storage device by pulse width modulation (Pulse Width Modulation, PWM) control based on the three-phase voltage reference value of the energy storage device.
Taking the structure shown in fig. 3 as an example, in the case where the energy storage device is the flywheel energy storage unit 310, the flywheel bridge circuit module 322 of the flywheel motor converter 320 may be controlled by PWM control to achieve charging of the energy storage device based on the dc bus voltage or discharging of the dc bus voltage using the energy storage device, thereby controlling the dc bus voltage to the dc bus voltage reference value mentioned in step S51.
The control process according to the exemplary embodiment of the present disclosure is described above with reference to fig. 5, in which the energy storage device may be connected to the dc bus of the fan converter to allow the dc bus voltage to be controlled by controlling the charging or discharging of the energy storage device, so that the control of the fan converter and the dc bus may be unbundled, and thus other control processes may be implemented using the fan converter, improving the controllability of the unit.
The following describes in detail the control process of the flywheel energy storage converter with reference to fig. 6, taking the energy storage device as a flywheel energy storage unit as an example.
As shown in fig. 6, the reference value U may be based on a preset dc bus voltage ref And the obtained direct current bus voltage U, and determining a direct current bus voltage error U between the obtained direct current bus voltage U and the obtained direct current bus voltage U err Active current reference value i of flywheel energy storage unit is determined through proportional integral control PI fq_ref 。
Weak magnetic ring control line electricity capable of being based on preset flywheel energy storage unitPressure reference value U flmax And the obtained flywheel motor line voltage U fl Determining a reactive current reference value i of a flywheel energy storage unit fd_ref 。
Here, at flywheel motor line voltage U fl Is greater than or equal to the voltage reference value U of the weak magnetic ring control line flmax Can be based on the difference U of the two f_err Determining a reactive current reference value i through proportional integral control PI fd_ref 。
Can be based on the active current reference value i of the flywheel energy storage unit fq_ref And reactive current reference i fd_ref And the obtained active current i of the flywheel motor of the flywheel energy storage unit fq And reactive current i fd Determining a quadrature axis voltage reference value v of the flywheel energy storage unit fq_ref And a direct axis voltage reference v fd_ref 。
Here, the rotor angle θ of the flywheel energy storage unit may be based on r And flywheel motor three-phase current I fabc Determining the active current i by inverse transformation of a coordinate system fq And reactive current i fd 。
Can be based on the quadrature axis voltage reference value v fq_ref And a direct axis voltage reference v fd_ref Determining a three-phase voltage reference value V of the flywheel energy storage unit fabc_ref And controlling the flywheel energy storage unit to charge or discharge so as to control the voltage of the direct current bus.
Based on the control method for the energy storage device, the control of the grid-side converter of the fan converter and the direct-current bus voltage can be unbinding, so that other control processes can be realized based on the grid-side converter, and the controllability of the unit is improved.
Two examples of control of the grid-side converter will be described below with reference to fig. 7 to 10.
In one example, the grid side current transformer of the fan current transformer may be controlled based on a current source.
Fig. 7 is a schematic flowchart showing a first example of control of a grid-side converter in a control method of a wind turbine generator system according to an exemplary embodiment of the present disclosure, and fig. 8 is a schematic diagram showing a first example of control of a grid-side converter of a wind turbine generator system according to an exemplary embodiment of the present disclosure.
As shown in fig. 7, the control method of the wind turbine generator set may further include:
in step S71, a direct current reference value of the grid-side converter may be determined based on the preset grid-side active power reference value and the obtained grid-side active power.
Here, the network-side active power reference value may be arbitrarily set according to actual needs, and may be a control target value for the network-side active power. The network side active power can be acquired through real-time acquisition and can be used as a feedback value.
In this step, as shown in fig. 8, the preset network side active power reference value P may be compared ref And the current collected network side active power P, determining an active power difference value P between the current collected network side active power P and the current collected network side active power P err And the active power difference P can be used err Is input into a controller to determine a direct-axis current reference value i for controlling the grid-side converter d_ref . Here, the controller is, for example, but not limited to, a proportional integral controller (PI as shown in fig. 8).
In step S72, a quadrature current reference value of the grid-side converter may be determined based on the preset grid-side reactive power reference value and the obtained grid-side reactive power.
Here, the network-side reactive power reference value may be arbitrarily set according to actual needs, and it may be a control target value for the network-side reactive power. The reactive power at the network side can be acquired through real-time acquisition and can be used as a feedback value.
In this step, as shown in fig. 8, the preset network side reactive power reference value Q may be compared ref And the current collected network side reactive power Q, determining a reactive power difference Q between the current collected network side reactive power Q and the current collected network side reactive power Q err And can be used for measuring the reactive power difference Q err Is input into a controller to determine a quadrature current reference value i for controlling the grid-side converter q_ref . Here, the controller is, for example, but not limited to, a proportional integral controller (PI as shown in fig. 8).
In step S73, the grid-side converter may be controlled based on the direct-axis current reference value, the quadrature-axis current reference value, and the acquired grid-side three-phase voltage and grid-side three-phase current.
Here, the grid-side three-phase voltage and the grid-side three-phase current may be acquired by real-time acquisition.
As an example, in this step, as shown in fig. 8, the three-phase voltage V on the net side can be based on abc Determining the grid phase angle θ by a phase-locked operation (e.g., by a phase-locked loop (Phase Locked Loop, PLL) module) grid . The grid-side three-phase voltages V can be respectively converted by a coordinate system conversion (e.g., clarke transformation process) based on the grid phase angle abc And network side three-phase current I abc Converted into a net-side two-phase voltage in a rotating coordinate system (e.g., a direct axis voltage v as shown in FIG. 8 d And quadrature axis voltage v q ) And a net side two-phase current (e.g., a straight axis current i as shown in fig. 8 d And quadrature axis current i q )。
As shown in fig. 8, the voltage reference value v of the grid-side converter in the two-phase stationary coordinate system can be determined by using the direct-axis current reference value and the quadrature-axis current reference value as target values of the current control of the grid-side converter through the voltage outer loop control and the current inner loop control based on the grid-side three-phase voltage, the grid-side three-phase current, the grid-side two-phase voltage, the grid-side two-phase current, the grid phase angle, the direct-axis current reference value and the quadrature-axis current reference value α_ref And v β_ref 。
In this way, the voltage reference value of the grid-side converter in the two-phase stationary coordinate system can be converted into the three-phase voltage reference value V of the grid-side converter in the three-phase stationary coordinate system by inverse transformation (e.g., clarke inverse transformation process) with the coordinate system conversion described above based on the voltage reference value of the grid-side converter in the two-phase stationary coordinate system and the grid phase angle gabc_ref 。
Thus, as shown in fig. 8, the three-phase voltage reference V of the grid-side converter can be based on gabc_ref The network side converter is controlled by, for example, PWM control, whereby control of the network side active power and the network side reactive power is achieved.
In the existing control scheme, the network side active power cannot be controlled independently of the direct current bus voltage due to the control binding of the network side converter and the direct current bus voltage. However, according to the control method described above with reference to fig. 7 and 8, on the one hand, the net-side active power reference value may be preset according to actual needs, or, in other words, the net-side active power may be controlled independently of the dc bus voltage; on the other hand, decoupling control can be carried out on the active power of the network side and the reactive power of the network side, so that the controllability of the unit is improved.
In another example, the grid side converter of the fan converter may be controlled based on a voltage source.
Fig. 9 is a schematic flowchart showing a second example of control of the grid-side converter in the control method of the wind turbine generator system according to the exemplary embodiment of the present disclosure, and fig. 10 is a schematic diagram showing a second example of control of the grid-side converter of the wind turbine generator system according to the exemplary embodiment of the present disclosure.
As shown in fig. 9, the control method of the wind turbine generator set may further include:
in step S91, a grid phase angle reference value of the grid-side converter may be determined based on the preset grid-side active power reference value and the grid rated angular velocity, and the obtained grid-side active power and the obtained grid angular velocity.
Here, the network-side active power reference value may be arbitrarily set according to actual needs, and may be a control target value for the network-side active power. The network side active power can be acquired through real-time acquisition and can be used as a feedback value. The rated angular speed of the power grid can be set according to the actual power grid, and the angular speed of the power grid can be acquired through real-time acquisition.
In this step, as shown in fig. 10, on the one hand, the net side active power reference value P can be compared ref And the network side active power P, and determining the power difference between the network side active power P and the network side active power P. Alternatively, the nominal angular velocity ω of the grid may be compared 0 And grid angular velocity ω, determining the active and frequency droop relationship, e.g. by a factor K ω To represent. By a proportional coefficientJω 0 -1 Realizing closed-loop control and angular speed omega of power grid by integrating and feedback coefficient D 0 Feedforward control is carried out to obtain an angular velocity reference valueThus, by the diagonal speed reference value +.>Integrating to obtain a power grid phase angle reference value +.>
However, the manner of determining the grid phase angle reference value is not limited to the above-described process, but may be determined in other manners.
In step S92, a network side voltage amplitude reference value of the network side converter may be determined based on the preset network side reactive power reference value and the obtained network side reactive power.
Here, the network-side reactive power reference value may be arbitrarily set according to actual needs, and it may be a control target value for the network-side reactive power. The reactive power at the network side can be acquired through real-time acquisition and can be used as a feedback value.
In this step, as shown in fig. 10, the preset network side reactive power reference value Q may be compared ref And the acquired network side reactive power Q, and determining reactive power and a voltage sag coefficient n. By comparing reactive power with a voltage sag factor n and a nominal voltage reference U 0 Determining a net side voltage amplitude reference value
In step S93, the grid-side converter may be controlled based on the grid phase angle reference value and the grid-side voltage amplitude reference value.
In this step, the three-phase voltage reference value of the grid-side converter can be generated by means of voltage-current internal loop control based on the grid phase angle reference value and the grid-side voltage amplitude reference value. Three-phase voltage of network side converterConverting the reference value into a coordinate system to obtain a voltage reference value U of the grid-side converter under a two-phase static coordinate system αref And U βref Therefore, the network side converter can be controlled to realize the control of the network side active power and the network side reactive power.
Fig. 8 and 10 show a current source type and a voltage source type grid-side converter control method, respectively, according to which the grid-side controllers of the fan converters can be flexibly switched according to the grid-connection requirements of the units.
Grid-connected requirements can be determined based on grid short-circuit impedance ratio SCR, under the condition of a strong grid (SCR > =2), a current source control mode shown in FIG. 8 can be adopted for unit grid-side control, and under the condition of a weak grid (SCR < 2), a voltage source control mode shown in FIG. 10 can be adopted for unit grid-side control, so that the grid-connected capacity of the unit can be improved, the adaptability of the weak grid and the strong grid can be improved, and the problem that free switching of grid-side voltage source control and current source control cannot be realized in the existing scheme is solved.
Further, according to exemplary embodiments of the present disclosure, since stabilization of the dc bus voltage may be controlled by the energy storage device, it may be allowed that the grid side control may be flexibly switched between the current source control mode and the voltage source control mode.
In the control method for the grid-side converter described above with reference to fig. 7 to 10, the grid-side active power reference value and the grid-side reactive power reference value can be determined as a function of the grid conditions under different grid conditions.
In an example, during the period that the wind generating set experiences high voltage/low voltage fault ride through, the grid-side active power reference value P can be set according to the requirements of the wind farm according to the condition of high and low grid voltage ref And network side reactive power reference value Q ref 。
For example, the grid-side active power reference value and the grid-side reactive power reference value may be determined from a preset apparent power in response to a high voltage failure or a low voltage failure of the wind turbine.
Specifically come fromThat is, if the reactive power priority is set during the high voltage/low voltage fault ride through experienced by the wind turbine, the maximum amplitude P of the active power reference value may be limited by the following equation (1) max ：
If active power priority is set during high voltage/low voltage fault ride through experienced by the wind turbine, the maximum amplitude Q of the reactive power reference value may be limited by the following equation (2) max ：
In the above formulas (1) and (2), S is a preset apparent power.
In addition, during the period that the wind generating set experiences high voltage/low voltage fault ride through, the active power reference value P on the grid side can also be directly set ref And network side reactive power reference value Q ref Corresponding net side active current reference value I P_ref And network side reactive current reference value I Q_ref 。
In another example, during the period that the wind turbine generator system experiences an inertia response, the net-side active power reference value may be determined by: acquiring a network side active power reference value and inertia response power of the wind generating set before inertia response; and determining the network side active power reference value of the wind generating set after inertia response based on the network side active power reference value before inertia response and the inertia response power.
Specifically, taking the control modes shown in fig. 7 and 8 as an example, the network-side active power reference value P ref May include a net side active power reference value P prior to inertia response ref0 And inertia response powerWherein (1)>The frequency change rate of the power grid; k (k) i Is an inertia constant, which may be set according to the active support requirements of the wind farm for inertia response.
Thus, during the period that the wind generating set experiences inertia response, the net side active power reference value P can be determined by the following equation (3) ref ：
In yet another example, during a wind turbine experiencing primary frequency modulation, the net side active power reference value may be determined by: acquiring a network side active power reference value and primary frequency modulation power of a wind generating set before primary frequency modulation; and determining the network side active power reference value of the wind generating set after primary frequency modulation based on the network side active power reference value before primary frequency modulation and the primary frequency modulation power.
Specifically, taking the control modes shown in fig. 7 and 8 as an example, the network-side active power reference value P ref May include a network side active power reference value P before primary frequency modulation ref0 And primary frequency modulation power k f Δf, where Δf is the grid frequency deviation; k (k) f The frequency modulation constant can be set according to the active support requirement of the wind power plant on primary frequency modulation.
Thus, during a period in which the wind turbine undergoes primary frequency modulation, the net-side active power reference value P can be determined by the following equations (4) and (5) ref ：
P ref ＝P ref0 +k i Δf (4)
Δf＝f rate -f (5)
Wherein f rate For the grid rated frequency, it may be, for example, 50Hz or 60Hz, f being the actual grid frequency value.
The above describes a method for determining a net side active power reference value for a wind power generator set at primary frequency modulation, during which the wind power generator set undergoes secondary frequency modulation, the net side active power reference value may be determined by: acquiring a network side active power instruction value and a current grid-connected active power instruction value of the wind generating set; and determining a network side active power reference value based on the network side active power instruction value and the current grid-connected active power instruction value of the unit.
Specifically, taking the control modes shown in fig. 7 to 10 as an example, the network side active power command value P during the secondary frequency modulation can be issued by the scheduling system s The command value may be specified according to the secondary frequency modulation requirement. Current grid-connected active power instruction value P ref0 Can be obtained according to the instruction issuing record.
Thus, during the period of the wind generating set undergoing the secondary frequency modulation, the net side active power reference value P can be determined by the following formula (6) ref ：
P ref ＝P ref0 +P s (6)
Based on the above-described examples, the problem that in the existing control scheme, the active support functions such as unit inertia response, primary frequency modulation, secondary frequency modulation and the like are complex due to the fact that the constraint of the balance of the unit side power and the network side power cannot be eliminated can be solved, and according to the exemplary embodiment of the disclosure, the independent control of the network side power can be realized by decoupling the control of the network side power and the direct current bus voltage, so that the constraint of the balance of the unit side power and the network side power is eliminated, and the higher unit controllability is allowed to be realized, and particularly under different power grid working conditions, the network side active power reference value can be set according to the current working condition requirements.
In addition to the above-mentioned operating conditions, the net-side active power reference value may also be determined based on other operating conditions.
In the case of a wind power plant for power prediction compensation, the grid-side active power reference value can be determined by: predicting unit prediction power of a wind generating unit; and determining a network side active power reference value based on the unit predicted power.
Specifically, the unit power P may be predicted by an arbitrary prediction system c Can control the network side powerRate reference P ref Equal to the predicted power, i.e. P ref ＝P c 。
In addition, according to the exemplary embodiment of the disclosure, since the dc bus voltage can be controlled by controlling the charging or discharging of the energy storage device, the grid-side power and the machine-side power of the wind generating set are decoupled, so that the grid-side power can be controlled by the fan converter, that is, the fixed grid-side power reference value is set, the power smoothing of the wind generating set can be realized, and the problem that the grid-connected power (or the grid-side power) cannot be stably output when the wind speed changes in the existing control scheme is solved.
In addition, according to the exemplary embodiment of the disclosure, since the dc bus voltage can be controlled by controlling the charging or discharging of the energy storage device, so that the grid-side power and the machine-side power of the wind generating set are decoupled, when the reactive power of the set is required to be supported, the reactive power reference value of the grid-side can be set according to the reactive power scheduling requirement in the wind farm, when the set needs to send reactive power, and the controllability of the reactive power of the grid-side is improved.
In addition, according to the exemplary embodiments of the present disclosure, since the dc bus voltage may be controlled by controlling the charging or discharging of the energy storage device, the dc bus voltage may be controlled to remain stable, and thus, it may be ensured that the wind turbine may be normally started in the black start control mode of the wind turbine.
The control process of the wind power generation set to the energy storage device according to the exemplary embodiment of the present disclosure is described above with reference to fig. 2 to 6, and the control process of the wind power generation set to the grid-side converter according to the exemplary embodiment of the present disclosure is described with reference to fig. 7 to 10. Furthermore, according to an exemplary embodiment of the present disclosure, the control of the machine side converter may be combined with the control procedure of fig. 2 to 10 described above.
Fig. 11 illustrates a control process of a machine side converter of a wind turbine generator set according to an exemplary embodiment of the present disclosure. Fig. 12 shows a schematic block diagram of control of a machine side converter of a wind park according to an exemplary embodiment of the present disclosure.
As shown in fig. 11, the control method according to an exemplary embodiment of the present disclosure may further include the steps of:
in step S111, an output active current reference value of the generator may be determined based on the preset maximum active power and the obtained output active power of the generator of the wind turbine generator set.
Here, the maximum active power may be arbitrarily set according to actual needs, and may be a control target value for the output active power of the generator. The output active power of the generator can be acquired through real-time acquisition.
In this step, as shown in fig. 12, the preset maximum active power P may be compared MPPT And the current output active power P of the generator G Determining the difference P between the two G_err And can be used for comparing the difference P G_err Is input into a controller to determine an active current reference value i for controlling the output active power of the generator Gq_ref . Here, the controller is, for example, but not limited to, a proportional-integral controller.
In addition, active power P MPPT Angular frequency omega based on fan generator Gr Determined by maximum power point tracking (Maximum Power Point Tracking, MPPT).
In step S112, an output reactive current reference value of the generator may be determined based on the preset generator voltage reference value and the obtained generator voltage.
Here, the generator voltage reference value may be set arbitrarily according to actual needs, for example, it may be a maximum set value of the generator field weakening voltage, and in the process of controlling the generator, the field weakening voltage of the generator may be controlled so as not to exceed the generator voltage reference value. The generator voltage may be acquired by real-time acquisition, which may be a feedback value.
In this step, as shown in FIG. 12, if the generator voltage U Gl Less than the generator voltage reference U Glmax Then the output reactive current reference value of the generator can be determined to be 0; if the generator voltage U Gl Greater than or equal toEqual to the generator voltage reference U Glmax Then it can be based on the generator voltage U Gl And a generator voltage reference U Glmax And determining an output reactive current reference value of the generator.
In particular, by comparing a preset generator voltage reference value U Glmax And the currently acquired generator voltage U Gl Determining the difference U between the two err And can be used for comparing the difference U err Is input into the controller to determine a reactive current reference i for controlling the generator voltage Gd_ref . Here, the controller is, for example, but not limited to, a proportional-integral controller.
In step S113, a quadrature axis voltage reference value and a direct axis voltage reference value of the generator may be determined based on the output active current reference value, the output reactive current reference value, and the obtained active current and reactive current of the generator.
Here, the active and reactive currents of the generator may be acquired through real-time acquisition, or may be determined by converting three-phase currents of the generator into two-phase currents in a rotating coordinate system through coordinate system conversion (e.g., clarke transformation process).
Specifically, as shown in FIG. 12, the rotor angle θ of the generator may be acquired Gr And three-phase current I of generator Gabc In this way, it is possible to base on the rotor angle θ Gr The three-phase current I of the generator is converted, for example, by Clarke transformation Gabc Converted into two-phase currents in a rotating coordinate system, i.e. active current i of the generator Gq And reactive current i Gd 。
In the case that the active current reference value and the reactive current reference value of the generator and the active current and the reactive current of the generator are determined, the active current reference value and the reactive current reference value of the generator can be used as target values of current control of the generator through voltage outer loop control and current inner loop control, so that the quadrature axis voltage reference value v of the generator is determined Gq_ref And a direct axis voltage reference v Gd_ref . Here, the intersecting axis and the straight axis may correspond to two in the rotation coordinate system, respectivelyCoordinate axes, such as q-axis and d-axis.
In step S114, the machine side converter may be controlled based on the quadrature axis voltage reference value and the direct axis voltage reference value of the generator to control the output active power of the generator.
In this step, the rotor angle θ of the generator can be based on the inverse transformation (e.g., clarke inverse transformation process) transformed from the coordinate system described above Gr Will cross axis voltage reference value v Gq_ref And a direct axis voltage reference v Gd_ref Three-phase voltage reference value V converted into generator Gabc_ref 。
Can be based on the three-phase voltage reference value V of the generator Gabc_ref The output power of the generator is controlled by PWM control.
According to the exemplary embodiment of the disclosure, since the direct current bus voltage can be controlled through the energy storage device and the grid-side power can be controlled through the grid-side converter of the fan converter, decoupling control of the machine-side power and the grid-side power can be achieved, and therefore the machine-side converter of the fan converter can be enabled to achieve maximum power tracking without being limited by balance of the machine-side active power and the grid-side active power, and controllability of a unit is improved.
According to a third aspect of the present disclosure, a computer device is provided, which may include a processor and a memory.
In particular, the memory may be used to store program code and to transfer the program code to the processor. The processor may be adapted to execute the control method of the wind park according to the present disclosure according to instructions in the program code.
As an example, the computer device may be connected to a controller of the energy storage device, a controller of a converter in the wind power plant, or a main controller of the wind power plant; alternatively, the computer device may be provided in a controller of the energy storage device or in a controller of a converter in the wind power plant.
According to a fourth aspect of the present disclosure, a wind power plant is provided, which may comprise a control device of a wind power plant according to the present disclosure, or a computer arrangement according to the present disclosure.
As examples, the wind power generator set may be a direct drive wind power generator set, a semi-direct drive wind power generator set or a doubly fed wind power generator set.
Fig. 13 shows a schematic view of an example of a wind power plant being a doubly fed wind power plant. As shown in fig. 13, the output of the wind turbine converter of the wind power plant may be connected to a first power grid 410 and the output of the generator G may be connected to a second power grid 420.
According to the control method of the wind generating set and the wind generating set, the energy storage device can be connected to the direct current bus of the fan converter to allow the direct current bus voltage to be controlled by controlling the charging or discharging of the energy storage device, so that the fan converter and the direct current bus can be unbinding, other control processes can be realized by utilizing the fan converter, the high controllability of grid-connected power of the wind generating set and the grid-connected capacity (namely, the grid-connected adaptability) of the wind generating set can be realized, the problem of the deficiency of the conventional control function at present is solved, and the grid-connected applicability of the wind generating set and the high controllability of active power are realized.
In addition, according to the control method of the wind generating set and the wind generating set of the exemplary embodiment of the disclosure, because the direct current bus voltage can be controlled by controlling the energy storage device, the wind generating set can be allowed to run under the maximum wind power tracking, and the parallel grid-connected power of the wind generating set is completely controllable.
In addition, according to the control method of the wind generating set and the wind generating set, the machine side power and the network side power can be decoupled and controlled, so that the problems of inertia response, primary frequency modulation and secondary frequency modulation active support of the wind generating set are solved.
In addition, according to the control method of the wind generating set and the wind generating set, which are disclosed by the exemplary embodiment of the invention, the network side power of the set converter is not changed randomly, and the network side power is smooth.
In addition, according to the control method of the wind generating set and the wind generating set of the exemplary embodiment of the disclosure, since the direct current bus voltage can be controlled by controlling the energy storage device, the free switching of the conventional voltage source and current source control modes under the grid connection condition of the wind generating set can be realized.
In addition, according to the control method of the wind generating set and the wind generating set of the exemplary embodiments of the present disclosure, the active power control problem during the high voltage/low voltage fault ride through can be solved, the dc bus voltage can be controlled only by controlling the energy storage device without starting the brake unit, no electric energy loss is generated, and the high voltage/low voltage fault ride through capability is improved.
In addition, according to the control method of the wind generating set and the wind generating set of the exemplary embodiment of the disclosure, the direct current bus voltage can be controlled by controlling the energy storage device, so that the black start of the wind generating set can be realized.
In addition, according to the control method of the wind generating set and the wind generating set, the energy storage device can be controlled to ensure the stability of the voltage of the direct current bus, so that the grid-connected power quality is optimized, and the subharmonic problem generated by wind power tracking is solved.
In addition, according to the control method of the wind generating set and the wind generating set, decoupling control of the grid-side power and the machine-side power can be allowed, so that the grid-side power can be controlled according to the wind power predicted value, and the wind power prediction accuracy can be improved.
In addition, according to the control method of the wind generating set and the wind generating set of the exemplary embodiment of the disclosure, since the grid-side power and the machine-side power can be decoupled for control, free switching between the grid-connected control mode and the off-grid control mode of the wind generating set is easier to achieve.
In addition, according to the control method of the wind generating set and the wind generating set, the energy storage device can be controlled to ensure the stability of the voltage of the direct current bus, so that the method and the device are not limited by a braking unit, and the grid-connected reactive power supporting capability of the wind generating set is improved.
In addition, according to the control method of the wind generating set and the wind generating set, grid-side control can be flexibly switched to a current source or voltage control mode, so that grid connection capacity of the wind generating set is greatly improved, and weak grid adaptability of the wind generating set is improved.
The described features, structures, or characteristics of the disclosure may be combined in any suitable manner in one or more embodiments. In the above description, numerous specific details are provided to give a thorough understanding of embodiments of the present disclosure. One skilled in the relevant art will recognize, however, that the disclosed aspects may be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the disclosure.
While certain embodiments have been shown and described, it would be appreciated by those skilled in the art that changes and modifications may be made to these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.

Claims (11)

1. A control method of a wind power generation unit, wherein the wind power generation unit includes a fan converter and an energy storage device, the energy storage device is connected to a dc bus of the fan converter, the control method comprising:
determining an active current reference value of the energy storage device based on a preset direct current bus voltage reference value and the obtained direct current bus voltage;
determining a reactive current reference value of the energy storage device based on a preset energy storage device voltage reference value and the acquired energy storage device voltage;
determining a quadrature axis voltage reference value and a direct axis voltage reference value of the energy storage device based on the active current reference value and the reactive current reference value of the energy storage device and the obtained active current and reactive current of the energy storage device;
And controlling the energy storage device to charge or discharge based on the quadrature axis voltage reference value and the direct axis voltage reference value so as to control the direct current bus voltage.
2. The control method of claim 1, wherein the step of determining a reactive current reference value of the energy storage device comprises:
if the voltage of the energy storage device is smaller than the voltage reference value of the energy storage device, the reactive current reference value of the energy storage device is 0;
and if the voltage of the energy storage device is greater than or equal to the voltage reference value of the energy storage device, determining a reactive current reference value of the energy storage device based on a difference value between the voltage of the energy storage device and the voltage reference value of the energy storage device.
3. The control method of claim 1, wherein the fan converter comprises a grid-side converter, and wherein the control method further comprises:
determining a direct-axis current reference value of the network-side converter based on a preset network-side active power reference value and the acquired network-side active power;
determining a quadrature axis current reference value of the network side converter based on a preset network side reactive power reference value and the acquired network side reactive power;
and controlling the grid-side converter based on the direct-axis current reference value, the quadrature-axis current reference value and the acquired grid-side three-phase voltage and grid-side three-phase current so as to control the grid-side active power and the grid-side reactive power.
4. The control method of claim 1, wherein the fan converter comprises a grid-side converter, and wherein the control method further comprises:
determining a grid phase angle reference value of the grid-side converter based on a preset grid-side active power reference value, a grid rated angular speed and the obtained grid-side active power and grid angular speed;
determining a network side voltage amplitude reference value of the network side converter based on a preset network side reactive power reference value and the acquired network side reactive power;
and controlling the grid-side converter based on the grid phase angle reference value and the grid-side voltage amplitude reference value.
5. The control method of claim 1, wherein the fan converter comprises a machine side converter, wherein the control method further comprises:
determining an output active current reference value of a generator of the wind generating set based on a preset maximum active power and the obtained output active power of the generator;
determining an output reactive current reference value of the generator based on a preset generator voltage reference value and the acquired generator voltage;
determining a quadrature axis voltage reference value and a direct axis voltage reference value of the generator based on the output active current reference value, the output reactive current reference value and the obtained active current and reactive current of the generator;
And controlling the machine side converter based on the quadrature axis voltage reference value and the direct axis voltage reference value of the generator to control the output active power of the generator.
6. A control method according to claim 3 or 4, characterized in that the network side active power reference value and the network side reactive power reference value are determined by:
and responding to the high-voltage fault or the low-voltage fault of the wind generating set, and determining the network side active power reference value and the network side reactive power reference value according to the preset apparent power.
7. A control method according to claim 3 or 4, characterized in that the network side active power reference value is determined by:
acquiring a network side active power reference value and inertia response power of the wind generating set before inertia response; determining a network side active power reference value of the wind generating set after inertia response based on the network side active power reference value before inertia response and the inertia response power; or alternatively
Acquiring a network side active power reference value and primary frequency modulation power of the wind generating set before primary frequency modulation; determining a network side active power reference value of the wind generating set after primary frequency modulation based on the network side active power reference value before primary frequency modulation and the primary frequency modulation power; or,
Acquiring a network side active power instruction value and a current grid-connected active power instruction value of the wind generating set; and determining the network side active power reference value based on the network side active power instruction value and the current grid-connected active power instruction value of the unit.
8. A computer device, the computer device comprising a processor and a memory:
the memory is used for storing program codes and transmitting the program codes to the processor;
the processor is configured to execute the control method of the wind park according to any of the claims 1-7 according to instructions in the program code.
9. The computer device of claim 8, wherein the computer device is connected to a controller of the energy storage device, a controller of a converter in the wind power plant, or a master controller of the wind power plant; or,
the computer equipment is arranged in a controller of the energy storage device or a controller of a converter in the wind generating set.
10. A wind power plant, characterized in that it comprises a computer device according to claim 8 or 9.
11. The wind power generator set of claim 10, wherein the wind power generator set is a direct drive wind power generator set, a semi-direct drive wind power generator set, or a doubly fed wind power generator set.
CN202210610391.3A 2022-05-31 2022-05-31 Control method of wind generating set and wind generating set Pending CN117200313A (en)

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