CN112952911A - Virtual synchronization control method and system for grid-connected converter based on coupling inductor - Google Patents
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- 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
- H02J3/40—Synchronising a generator for connection to a network or to another generator
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- 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
- H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
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- 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
- H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
- H02J3/241—The oscillation concerning frequency
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- 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
- H02J3/388—Islanding, i.e. disconnection of local power supply from the network
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Abstract
The invention discloses a virtual synchronization control method and a system of a grid-connected converter based on coupling inductors, wherein the method comprises the following steps: constructing a virtual synchronous rotating coordinate system; fixing the output current vector of the grid-connected converter to a virtual synchronous rotating coordinate system, and taking the output current of the grid-connected converter as an exciting current; the output current vector of the grid-connected converter flows through a secondary winding of the coupling inductor to generate an excitation magnetic field penetrating through primary and secondary air gaps, and excitation induced electromotive force is generated at the primary side of the coupling inductor; the quadrature axis current of the primary side of the coupling inductor generates an armature magnetic field perpendicular to the excitation magnetic field, and influences the primary side electromagnetic power, and further influences the virtual electromagnetic torque, so that the rotating speed of the virtual synchronous rotating coordinate system is influenced. The invention relates to a virtual synchronous control method combining a grid-connected converter and an outlet coupling inductor, which takes the output current of a GSC (general-purpose current controller) as the exciting current of a secondary side of the coupling inductor to generate an exciting magnetic field and generate induced electromotive force on a primary side. And a current control link is reserved, and GSC overcurrent caused by disturbance is avoided.
Description
Technical Field
The invention relates to the technical field of grid-connected converter control, in particular to a virtual synchronous control method and system of a grid-connected converter based on coupling inductance.
Background
The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.
With the continuous improvement of the new energy occupation ratio, the traditional new energy grid-connected control mode based on phase-locked phase and power decoupling vector control faces many problems and challenges. For example: the power grid frequency and voltage support cannot be spontaneously provided, independent power supply cannot be realized by separating from a synchronous machine, and the problem of sub-super-synchronous oscillation is easily caused. In view of this, a new control concept, virtual synchronization control, is proposed.
Most of the existing virtual synchronous control of a grid-connected converter (hereinafter referred to as GSC) directly controls the GSC output voltage, so that the output voltage vector of the grid-connected converter has the motion characteristic described by a virtual rotor motion equation to simulate the excitation induced electromotive force of a synchronous motor, and in addition, a scheme of directly utilizing the direct-current bus voltage dynamic of a full-power converter type wind turbine generator set as the GSC output voltage vector rotation speed also exists. The schemes lack a current control link and easily cause the overcurrent of the converter under large disturbance.
Disclosure of Invention
In order to solve the problems, the invention provides a grid-connected converter virtual synchronous control method and a system based on coupling inductors, wherein the virtual synchronous control is realized by coupling inductors (such as a step-up transformer) at the output end of a GSC (general purpose inductor controller); the output current of the converter is used as the exciting current for control, so that a current vector control link is reserved, and the overcurrent danger of the converter can be effectively avoided.
In some embodiments, the following technical scheme is adopted:
a grid-connected converter virtual synchronization control method based on coupling inductance comprises the following steps:
constructing a virtual synchronous rotating coordinate system;
fixing the output current vector of the grid-connected converter to a virtual synchronous rotating coordinate system, and taking the output current of the grid-connected converter as an exciting current;
the output current vector of the grid-connected converter flows through a secondary winding of the coupling inductor to generate an excitation magnetic field penetrating through primary and secondary air gaps, and excitation induced electromotive force is generated at the primary side of the coupling inductor; the quadrature axis current of the primary side of the coupling inductor generates an armature magnetic field perpendicular to the excitation magnetic field, and influences the primary side electromagnetic power, and further influences the virtual electromagnetic torque, so that the rotating speed of the virtual synchronous rotating coordinate system is influenced.
In other embodiments, the following technical solutions are adopted:
a terminal device comprising a processor and a memory, the processor being arranged to implement instructions; the storage is used for storing a plurality of instructions, and the instructions are suitable for being loaded by the processor and executing the virtual synchronous control method of the grid-connected converter based on the coupled inductor.
In other embodiments, the following technical solutions are adopted:
a computer readable storage medium, wherein a plurality of instructions are stored, and the instructions are suitable for being loaded by a processor of a terminal device and executing the virtual synchronization control method of the grid-connected converter based on the coupled inductor.
Compared with the prior art, the invention has the beneficial effects that:
the invention relates to a virtual synchronous control method combining a grid-connected converter (GSC) and an outlet coupling inductor, which takes the output current of the GSC as the exciting current of a secondary side of the coupling inductor to generate an exciting magnetic field and generate induced electromotive force on a primary side. And a current control link is reserved, and GSC overcurrent caused by disturbance is avoided.
Firstly, constructing a virtual synchronous rotation coordinate system as a control reference; fixing the GSC output current vector to a d-axis of a virtual synchronous rotating coordinate system by using a current vector control method to form a coupling inductor secondary excitation magnetic field; a speed regulator link is added in the construction of a virtual synchronous coordinate system to stabilize the rotating speed and provide frequency active support for a power grid;
in the current vector control method, an automatic excitation regulation link is added to determine a current reference value so as to stabilize voltage and provide voltage active support for a power grid; the virtual synchronous control method not only enables the grid-connected converter to run in parallel with the synchronous machine and provides frequency and voltage active support for a power grid, but also can realize independent power supply island operation without depending on the synchronous machine.
Additional features and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
FIG. 1 is a schematic diagram of a GSC and outlet coupled inductor system according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a virtual synchronous rotating coordinate system constructed in an embodiment of the present invention;
FIG. 3 is a schematic diagram of a GSC current control structure according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of a virtual synchronous rotating coordinate system added with a speed regulator link according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of an automatic excitation adjusting link according to an embodiment of the present invention;
FIG. 6 is a schematic diagram of a simulation system according to an embodiment of the present invention;
FIG. 7 is a schematic diagram illustrating a GSC virtual synchronous speed and a synchronous motor rotor speed under the scenario of the embodiment of the present invention;
fig. 8 is a schematic diagram of GSC + coupled inductor and synchronous terminal voltage under the scenario of the embodiment of the present invention;
FIG. 9 is a schematic diagram of GSC + coupled inductor output power and power reference values under the exemplary scenario of the present invention;
FIG. 10 is a schematic diagram of SG1 output power and mechanical power under the scenario of the present invention;
FIG. 11 is a schematic diagram of SG2 output power and mechanical power under the scenario of the present invention;
FIG. 12 illustrates a d-axis current and a d-axis current reference value of a GSC in a virtual synchronous rotating coordinate system according to an embodiment of the present invention;
FIG. 13 is a diagram of q-axis current and q-axis current reference values of a GSC in a virtual synchronous rotating coordinate system according to an embodiment of the present invention;
FIG. 14 is a schematic diagram of a virtual synchronous speed of a GSC under a second scenario in an embodiment of the present invention;
fig. 15 is a schematic diagram of a terminal voltage of a GSC + coupled inductor in a second scenario according to the embodiment of the present invention;
fig. 16 is a schematic diagram of GSC + coupled inductor output power and power reference value under a second scenario in an embodiment of the present invention;
fig. 17 is a schematic diagram of d-axis current and a d-axis current reference value of a GSC in a virtual synchronous rotating coordinate system under a second scenario in the embodiment of the present invention;
fig. 18 is a schematic diagram of reference values of q-axis current and q-axis current of a GSC in a virtual synchronous rotating coordinate system under a second scenario in the embodiment of the present invention.
Detailed Description
It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
Example one
In one or more embodiments, a grid-connected converter virtual synchronization control method based on coupling inductance is disclosed, which specifically includes the following processes:
(1) constructing a virtual synchronous rotating coordinate system;
(2) fixing the output current vector of the grid-connected converter to a virtual synchronous rotating coordinate system, and taking the output current of the grid-connected converter as an exciting current;
(3) the output current vector of the grid-connected converter flows through a secondary winding of the coupling inductor to generate an excitation magnetic field penetrating through primary and secondary air gaps, and excitation induced electromotive force is generated at the primary side of the coupling inductor; the quadrature axis current of the primary side of the coupling inductor generates an armature magnetic field perpendicular to the excitation magnetic field, and influences the primary side electromagnetic power, and further influences the virtual electromagnetic torque, and further influences the virtual synchronous rotor rotating speed.
Specifically, the GSC output current is taken as the excitation current. And constructing a virtual synchronous rotating coordinate system to be used as a control reference of the secondary GSC output current, fixing the GSC output current position under the virtual synchronous rotating coordinate system (fixed on a d-axis of the virtual synchronous rotating coordinate system) to generate an excitation magnetic field which passes through an air gap for synchronous rotation, and generating excitation induced electromotive force on a primary side (a GSC side of the coupling inductor is called as a secondary side, and a power grid side is called as a primary side).
The quadrature component of the primary side current is related to the motion equation of the virtual synchronous rotating coordinate system to form a quadrature armature reaction effect, the primary side quadrature component current influences the virtual synchronous rotating speed, and a speed regulator link is added in the virtual synchronous rotating coordinate system equation to cope with the quadrature component current change caused by external disturbance.
The primary side direct axis current has demagnetization or magnetism-assisting effect, and the amplitude of an air gap magnetic field is influenced, so that the amplitude of induced electromotive force and the amplitude of primary side voltage is influenced, therefore, an automatic excitation regulation control link is added to regulate the amplitude of GSC output current according to the amplitude change of the terminal voltage so as to change the size of an excitation magnetic field, maintain the terminal voltage to be stable, and cope with the direct axis current change caused by external disturbance.
According to the control scheme, the output current of the converter is used as the exciting current to be controlled, and the GSC output current is controlled by using a current vector control method, so that the overcurrent danger of the converter can be effectively avoided; in addition, active voltage and frequency support can be provided for a power grid, and independent operation of an island of an asynchronous machine can be realized.
A schematic diagram of a GSC and outlet coupled inductive system is shown in FIG. 1, wherein
Outputting current, namely coupling inductance secondary side current, for the GSC;
for grid side currents, i.e. primary side of coupled inductorCurrent flow;
is the primary side voltage. The coupling inductor may be a step-up transformer at the GSC outlet.
Firstly, a virtual synchronous rotation coordinate system is constructed, and the expression of the corresponding equation is as follows:
wherein ,Tm_vsAs virtual mechanical torque, Te_vsAs virtual electromagnetic torque, PrefIs an active power reference value, PesIs the primary electromagnetic power, D is the damping coefficient, J is the virtual inertia, omegarvFor virtually synchronizing rotor speeds, omegasIs the primary current vector rotation speed.
A virtual synchronization coordinate system is constructed according to this equation, as shown in fig. 2. Where θ is the virtual synchronous coordinate system angle. Outputting a GSC current vector
And the d-axis is fixed on the virtual synchronous rotating coordinate system.
The corresponding current vector control structure is shown in fig. 3: the current reference value of the grid-connected converter in the virtual synchronous coordinate system only has a d-axis component, a voltage modulation signal is obtained through a PI (proportional-integral) regulator after the difference is made between the reference value and the current measurement feedback value, a switching signal of the grid-connected converter is obtained through SPWM (sinusoidal pulse width modulation), and the switching on and off of a switching tube of the grid-connected converter are controlled to obtain a modulation voltage to control the output current.
wherein Ig_refAmplitude reference value, i, for GSC output currentgd、igqAnd outputting the dq axis component of the current under the virtual synchronous rotating coordinate system for the GSC.
And the current flows through the secondary winding to generate an excitation magnetic field passing through the primary and secondary air gaps, and an excitation induced electromotive force is generated on the primary side. Quadrature axis of primary sideThe (q-axis) current will generate an armature magnetic field perpendicular to the excitation magnetic field, affecting the primary electromagnetic power PesAnd further influence the virtual electromagnetic torque Te_vsThereby influencing the virtual synchronous rotor speed ωrv。
The direct axis (d axis) current of the primary side generates an armature magnetic field which is in the same direction as the excitation magnetic field, has demagnetization or magnetism-assisting effect, greatly influences the amplitude of an air gap magnetic field, and further influences the primary side induced electromotive force and terminal voltage
The amplitude of (c).
In order to cope with the influence of the change of the primary quadrature axis current caused by the external disturbance, a speed regulator link can be added to the construction of the virtual synchronous coordinate system shown in fig. 2 to maintain the virtual synchronous rotating speed, as shown in fig. 4: and subtracting the 1.0 rotating speed standard value from the virtual synchronous rotating coordinate system rotating speed per unit value, multiplying the difference by a speed regulator gain coefficient, and obtaining the power of the speed regulator in the forming process of the virtual synchronous rotating coordinate system through a first-order inertia link so as to maintain the rotating speed of the virtual synchronous rotating coordinate system to be near the 1.0 standard value.
To counter the effects of the primary direct axis current, an auto-excitation regulation element may be added to the current control structure shown in fig. 3 to determine Ig_refThe GSC output current and the formed excitation magnetic field amplitude are adjusted to maintain the amplitude of the air gap magnetic field and the terminal voltage, and the terminal voltage change caused by the primary side quadrature axis current can be responded, and the process of the automatic excitation adjusting link is as shown in fig. 5: and the terminal voltage standard value and the actual terminal voltage amplitude are subtracted, after a proportion link and an inertia link, an output current amplitude reference value increment of the grid-connected converter is obtained, and is added with the output current reference value of the grid-connected converter to obtain an output current amplitude reference value of the grid-connected converter, and the output current amplitude reference value is input to an output current vector control link of the grid-connected converter, so that the size of the exciting current is changed, and the terminal voltage is maintained.
wherein ,ω0For rated electrical angular velocity equal to 100 pi, Pref0For power reference value reference, PfFor speed regulator power increase, KfFor adjusting the difference coefficient of speed regulator，TfThe governor time constant is used to simulate the time delay of the change in mechanical power output of the turbine of the synchronous machine. U shape_refIs a reference value of the primary side voltage, Ig_ref0Reference value of amplitude of current output for GSC, Delta Ig_refOutputting a current magnitude reference increment, T, for the GSCeThe time constant is adjusted for automatic excitation.
It should be noted that a reliable implementation of this control scheme requires that the dc bus voltage level be increased so that the dc voltage level of the GSC allows the terminal voltage to output reactive power to the grid at a normal level without triggering a modulation voltage clipping.
Simulation verification:
the simulation system is shown in fig. 6. Wherein, the 3MWGSC adopts the virtual synchronous control method under the matching of the outlet matched coupling inductor. The two synchronizers have the functions of speed regulators and automatic excitation regulation. The system parameters are shown in table i.
TABLE I simulation System parameters
1. Scene one: operation under load access
After the load 3 is connected, the quadrature axis current of the GSC + coupling inductor and the two synchronizers is increased, so that the virtual electromagnetic torque of the GSC + coupling inductor is increased, the electromagnetic torque acting on the rotors of the synchronizers is increased, and the virtual synchronous rotating speed of the GSC + coupling inductor and the rotating speeds of the two synchronizers are reduced. At the moment, the GSC + coupling inductor and a speed regulator control link of the synchronous machine play a role, and a power reference value or the mechanical power output by the steam turbine is increased, so that the rotating speed is increased and finally stabilized at a new steady-state value.
On the other hand, the connection of the load 3 also increases the direct-axis current of each power generation unit, strengthens the direct-axis armature reaction of the demagnetization property, and reduces the terminal voltage. At the moment, the GSC + coupling inductor and an automatic excitation regulation control link of the synchronous machine play a role, the GSC output current reference value or the excitation voltage is increased, the GSC output current is increased, the rotor excitation current of the synchronous machine is increased, and therefore the excitation magnetic field amplitude value maintaining end voltage is increased. The output current of the GSC can be well controlled on a d-axis of a virtual synchronous coordinate system under a current vector control structure, and a reference value can be quickly and accurately tracked.
2. Scene two: synchronous machine cutting machine, GSC isolated island operation
After the synchronous machine is cut off from the system, the GSC can realize independent power supply by adopting the control method provided by the disclosure. After the synchronous machine is cut off, the quadrature axis current of the GSC + coupling inductor is increased, the output electromagnetic power is increased, the virtual synchronous rotating speed is reduced, at the moment, the speed regulator plays a role in a link, the power reference value is increased, and the virtual synchronous rotating speed is increased and finally stabilized. On the other hand, the direct axis current with the demagnetization property can also be increased to reduce the terminal voltage, at the moment, the automatic excitation regulation link plays a role, the GSC output current reference value is increased to increase the excitation magnetic field, and the terminal voltage is maintained.
According to the virtual synchronous control method combining the grid-connected converter (GSC) and the outlet coupling inductor, the output current of the GSC is used as the exciting current of the secondary side of the coupling inductor to generate an exciting magnetic field and generate induced electromotive force on the primary side. Firstly, constructing a virtual synchronous rotation coordinate system as a control reference; fixing the GSC output current vector to a d-axis of a virtual synchronous rotating coordinate system by using a current vector control method to form a coupling inductor secondary excitation magnetic field; a speed regulator link is added in the construction of a virtual synchronous coordinate system to stabilize the rotating speed and provide frequency active support for a power grid; in the current vector control method, an automatic excitation regulation link is added to determine a current reference value so as to stabilize voltage and provide voltage active support for a power grid; the virtual synchronous control method not only enables the grid-connected converter to run in parallel with the synchronous machine and provides frequency and voltage active support for a power grid, but also can realize independent power supply island operation without depending on the synchronous machine.
Example two
In one or more embodiments, a terminal device is disclosed, which includes a server, where the server includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor executes the computer program to implement the virtual synchronous control method for the grid-connected converter based on the coupling inductance in the first embodiment. For brevity, no further description is provided herein.
It should be understood that in this embodiment, the processor may be a central processing unit CPU, and the processor may also be other general purpose processors, digital signal processors DSP, application specific integrated circuits ASIC, off-the-shelf programmable gate arrays FPGA or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and so on. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
The memory may include both read-only memory and random access memory, and may provide instructions and data to the processor, and a portion of the memory may also include non-volatile random access memory. For example, the memory may also store device type information.
In implementation, the steps of the above method may be performed by integrated logic circuits of hardware in a processor or instructions in the form of software.
The virtual synchronization control method for the grid-connected converter based on the coupling inductor in the first embodiment can be directly implemented by a hardware processor, or implemented by combining hardware and software modules in the processor. The software modules may be located in ram, flash, rom, prom, or eprom, registers, among other storage media as is well known in the art. The storage medium is located in a memory, and a processor reads information in the memory and completes the steps of the method in combination with hardware of the processor. To avoid repetition, it is not described in detail here.
Those of ordinary skill in the art will appreciate that the various illustrative elements, i.e., algorithm steps, described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.
Example four
In one or more embodiments, a computer-readable storage medium is disclosed, in which a plurality of instructions are stored, the instructions being suitable for being loaded by a processor of a terminal device and implementing the virtual synchronization control method for the grid-connected converter based on the coupled inductor in the first embodiment.
Although the embodiments of the present invention have been described with reference to the accompanying drawings, it is not intended to limit the scope of the present invention, and it should be understood by those skilled in the art that various modifications and variations can be made without inventive efforts by those skilled in the art based on the technical solution of the present invention.
Claims (10)
1. A grid-connected converter virtual synchronization control method based on coupling inductance is characterized by comprising the following steps:
constructing a virtual synchronous rotating coordinate system;
fixing the output current vector of the grid-connected converter to a virtual synchronous rotating coordinate system, and taking the output current of the grid-connected converter as an exciting current;
the output current vector of the grid-connected converter flows through a secondary winding of the coupling inductor to generate an excitation magnetic field penetrating through primary and secondary air gaps, and excitation induced electromotive force is generated at the primary side of the coupling inductor; the quadrature axis current of the primary side of the coupling inductor generates an armature magnetic field perpendicular to the excitation magnetic field, and influences the primary side electromagnetic power, and further influences the virtual electromagnetic torque, so that the rotating speed of the virtual synchronous rotating coordinate system is influenced.
2. The virtual synchronous control method of the grid-connected converter based on the coupling inductor as claimed in claim 1, wherein the direct-axis current of the primary side of the coupling inductor generates an armature magnetic field which is in the same direction as the excitation magnetic field, has a demagnetization or magnetism-assisting effect, and affects the amplitudes of the primary side induced electromotive force and the terminal voltage.
3. The virtual synchronous control method of the grid-connected converter based on the coupled inductor as claimed in claim 1, wherein a speed regulator link is added to a virtual synchronous coordinate system to maintain a virtual synchronous rotating speed.
4. The grid-connected converter virtual synchronous control method based on the coupling inductor as claimed in claim 3, wherein a speed regulator link is added in a virtual synchronous coordinate system, and the specific process is as follows:
and the rotating speed standard value and the rotating speed per unit value of the virtual synchronous rotating coordinate system are subjected to subtraction, the speed regulator gain coefficient is multiplied, and then the power of the speed regulator in the forming process of the virtual synchronous rotating coordinate system is obtained through a first-order inertia link, so that the rotating speed of the virtual synchronous rotating coordinate system is maintained to be close to the rotating speed standard value.
5. The method as claimed in claim 1, wherein an automatic excitation adjusting link is added to the current control structure of the grid-connected converter to determine the amplitude reference value of the output current of the grid-connected converter, adjust the amplitude of the output current and the formed excitation magnetic field of the grid-connected converter, maintain the amplitude of the air gap magnetic field and the terminal voltage, and respond to the terminal voltage change caused by the primary side alternating current and the primary side direct current.
6. The method for virtually synchronously controlling the grid-connected converter based on the coupled inductor according to claim 5, wherein an automatic excitation regulation link is added to a current control structure of the grid-connected converter, and the specific process is as follows: and the terminal voltage standard value and the actual terminal voltage amplitude are subtracted, after a proportion link and an inertia link, an output current amplitude reference value increment of the grid-connected converter is obtained, and is added with the output current reference value of the grid-connected converter to obtain an output current amplitude reference value of the grid-connected converter, and the output current amplitude reference value is input to an output current vector control link of the grid-connected converter, so that the size of the exciting current is changed, and the terminal voltage is maintained.
7. The grid-connected converter virtual synchronous control method based on the coupling inductor as claimed in claim 1, wherein a virtual synchronous rotating coordinate system is constructed, and specifically:
wherein ,
Tm_vsas virtual mechanical torque, Te_vsAs virtual electromagnetic torque, PrefIs an active power reference value, PesIs the primary electromagnetic power, D is the damping coefficient, J is the virtual inertia, omegarvFor virtually synchronizing rotor speeds, omegasIs the primary current vector rotation speed.
8. The virtual synchronous control method of the grid-connected converter based on the coupled inductor as claimed in claim 1, wherein the output current vector control structure of the grid-connected converter is specifically as follows:
the current reference value of the grid-connected converter in the virtual synchronous coordinate system only has a d-axis component, a voltage modulation signal is obtained through a PI (proportional-integral) regulator after the difference is made between the reference value and the current measurement feedback value, a switching signal of the grid-connected converter is obtained through SPWM (sinusoidal pulse width modulation), and the switching on and off of a switching tube of the grid-connected converter are controlled to obtain a modulation voltage to control the output current.
9. A terminal device comprising a processor and a memory, the processor being arranged to implement instructions; the memory is used for storing a plurality of instructions, and the instructions are suitable for being loaded by the processor and executing the virtual synchronization control method of the grid-connected inverter based on the coupled inductor, according to any one of claims 1 to 7.
10. A computer readable storage medium storing a plurality of instructions, wherein the instructions are adapted to be loaded by a processor of a terminal device and to execute the virtual synchronization control method for a coupled inductance based grid-connected converter according to any one of claims 1 to 7.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104716886A (en) * | 2015-03-31 | 2015-06-17 | 西安交通大学 | Virtual impedance voltage converter-based control method of virtual synchronous motor |
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| CN112952911B (en) | 2023-05-26 |
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