CN115579872B - Current tracking control method for virtual synchronous machine - Google Patents
Current tracking control method for virtual synchronous machine Download PDFInfo
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- CN115579872B CN115579872B CN202211252783.3A CN202211252783A CN115579872B CN 115579872 B CN115579872 B CN 115579872B CN 202211252783 A CN202211252783 A CN 202211252783A CN 115579872 B CN115579872 B CN 115579872B
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- synchronous machine
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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
- H02J3/001—Methods to deal with contingencies, e.g. abnormalities, faults or failures
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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
- H02J3/46—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
Abstract
The invention discloses a virtual synchronous machine current tracking control method, which comprises the steps of obtaining reactive current difference by making difference between reactive current set value of a virtual synchronous machine and actual reactive current of the virtual synchronous machine, and taking the reactive current difference as G QR Inputting the links, and then summing the input links with voltage values of grid-connected points to obtain internal potential amplitude values, wherein the internal potential angle and the internal potential amplitude values f Directly carrying out coordinate transformation to obtain the output voltage of the virtual synchronous machine; or the internal potential angle, the internal potential amplitude and the grid-connected point voltage are controlled by G VAC The method can directly control the current of the virtual synchronous machine, ensure that the virtual synchronous machine can accurately control active and reactive currents during fault ride-through, ensure that the fault ride-through characteristics of the virtual synchronous machine are compatible with the existing power grid fault ride-through standard requirements, effectively limit the output current of the synchronous machine and reduce the overcurrent risk of the virtual synchronous machine.
Description
Technical Field
The invention relates to the technical field of grid connection, in particular to a current tracking control method of a virtual synchronous machine.
Background
In order to construct a new power system powered by renewable energy sources with a high proportion, even 100%, as an interface device between renewable energy sources and the power grid, the power electronic converter must take over more and more synchronous machine functions. The virtual synchronization technology simulates the running mode of the synchronous machine and naturally inherits various characteristics of the synchronous machine, so that the virtual synchronization technology becomes a research hot spot.
The existing virtual synchronous machine control mostly adopts a voltage source type control mode. And the active part in the power loop refers to a rotor swing equation of the synchronous machine, and the real-time active power of the virtual synchronous machine is used as feedback to obtain the internal potential angle of the virtual synchronous machine. And (3) referring to excitation control of the synchronous machine in the reactive part, and taking real-time reactive power of the virtual synchronous machine as feedback to obtain the virtual synchronous internal potential amplitude. And directly controlling the output voltage of the virtual synchronous machine according to the internal potential amplitude and the phase obtained by the power loop. The voltage source type virtual synchronous machine can directly control the voltage of the virtual synchronous machine, and has the advantage of stronger small disturbance stability. However, the current cannot be directly controlled, so that the overcurrent problem is easy to occur when the disturbance such as grid voltage drop, load abrupt change, grid voltage unbalance and the like is faced.
What is needed is a virtual synchronous machine current tracking control method which is capable of directly controlling output current of a virtual synchronous machine without changing a voltage source control mode of the virtual synchronous machine, accurately controlling current of power electronic devices, reducing risk of overcurrent in a fault process and better meeting requirements of power grid standards by modifying a power loop of an original voltage source type virtual synchronous machine into an active current loop and a reactive current loop and taking active current and reactive current of the virtual synchronous machine as feedback.
Disclosure of Invention
The invention aims to solve the technical problem of providing a current tracking control method of a virtual synchronous machine, which can directly control the current of the virtual synchronous machine, ensure that the virtual synchronous machine can accurately control active and reactive currents during fault ride-through under the condition of not changing the motion equation of the existing virtual synchronous machine, ensure that the fault ride-through characteristics of the virtual synchronous machine are compatible with the existing power grid fault ride-through standard requirements, effectively limit the output current of the synchronous machine and reduce the overcurrent risk of the virtual synchronous machine.
In order to solve the technical problems, the invention provides a current tracking control method of a virtual synchronous machine; the method comprises the following steps when controlling the active current and the reactive current of the virtual synchronous machine:
and making a difference between the set value of the active current of the virtual synchronous machine and the active current of the virtual synchronous machine, and taking the difference of the active current as mechanical active input of a synchronous machine rotor motion equation link.
Constructing a synchronous machine rotor motion equation, and passing the obtained active current difference through a phase-change generator1/T in integral link j s is a forward channel, an output signal is taken as a closed loop link of a negative feedback channel through a proportion link D, and then is summed with a rated angular frequency, and an internal potential power angle is obtained through a unit integration link.
And taking the reactive current difference as an input of a PI link, and then taking sum of the reactive current difference and the output voltage module value of the virtual synchronous machine to obtain an internal potential amplitude.
Preferably, in steady state, the active current set value of the virtual synchronous machine port is calculated from the active power set value of the virtual synchronous machine and the grid-connected point voltage module value. And the reactive current set value of the virtual synchronous machine port is directly set to be 0.
Preferably, during fault ride-through, the reactive current set value of the virtual synchronous port is calculated from the voltage module value of the grid-connected point according to the grid-connected requirement. The active current set value of the virtual synchronous machine port is calculated by the active power set value of the virtual synchronous machine and the grid-connected point voltage module value, and is limited by the reactive current set value. And the sum of the amplitude of the set active current value and the set reactive current value of the port of the virtual synchronous machine does not exceed the upper limit of the current of the virtual synchronous machine.
Preferably, the network access active current and the network access reactive current are active current and reactive current actually injected into the power grid by the port of the virtual synchronous machine.
Preferably, in the method for constructing the motion equation link of the rotor of the synchronous machine, the forward channel 1/Js corresponds to the moment of inertia link of the rotor, and the proportional negative feedback link D corresponds to the damping link of the rotor.
Preferably, the PI controller is a proportional plus integral regulator, which can eliminate the error given by direct current.
Preferably, the internal potential amplitude is obtained by feedforward of the voltage value of the grid-connected point and output of a reactive current deviation PI controller, so that the given tracking speed of the reactive current and the tracking precision of the reactive current are considered.
Preferably, the internal potential amplitude and the rotor angle may be directly subjected to coordinate transformation as inputs to the PWM wave generator. The voltage difference with the grid-connected point can be obtained, voltage feedforward is added through a PI controller, and the voltage difference is used as the input of the PWM wave generator. To obtain faster and more accurate virtual synchronous machine output voltage control.
After the method is adopted, the virtual synchronous machine current tracking control method makes a difference between the active current set value of the virtual synchronous machine and the active current of the virtual synchronous machine, and the active current difference is used as the mechanical active input of the synchronous machine rotor motion equation link. And constructing a synchronous machine rotor motion equation, namely performing a closed loop link taking an integration link as a forward channel, taking an output signal as a negative feedback channel through a proportion link D, summing the closed loop link with a rated angular frequency, and obtaining an internal potential power angle through a unit integration link. The reactive current set value of the virtual synchronous machine is differenced with the reactive current of the virtual synchronous machine, the reactive current difference is used as input of a PI link, and then the sum of the reactive current difference and the output voltage module value of the virtual synchronous machine is used for obtaining an internal potential amplitude; the virtual synchronous machine current tracking control method can directly control the output current of the virtual synchronous machine, so that the current controllability of the virtual synchronous machine is enhanced, the output current of the synchronous machine can be effectively limited when the power grid has voltage drop faults, the overcurrent risk of the virtual synchronous machine is reduced, and the current can be controlled according to the existing new energy power grid fault ride-through standard when the power grid has faults, so that the fault ride-through characteristics of the virtual synchronous machine are compatible with the existing power grid fault ride-through standard requirements.
Drawings
FIG. 1 is an overall system diagram of a virtual synchronous machine current tracking control method of the present invention;
FIG. 2 is an active current control diagram of a virtual synchronous machine current tracking control method according to a first embodiment of the present invention;
fig. 3 is a reactive current control diagram of a virtual synchronous machine current tracking control method according to the first embodiment of the present invention;
FIG. 4 is an active current and reactive current acquisition chart of a current tracking control method for a virtual synchronous machine according to a second embodiment of the present invention;
FIG. 5 is a diagram of a virtual synchronous machine current tracking control according to an embodiment of the present inventionThe virtual synchronous machine output voltage e is obtained in the manufacturing method vscref_α And e vscref_β The control diagram of the first mode;
fig. 6 shows a virtual synchronous machine output voltage e obtained in the virtual synchronous machine current tracking control method according to the first embodiment of the present invention vscref_α And e vscref_β Control diagram of mode two.
Detailed Description
The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
Example 1
Please refer to fig. 1, 2 and 3; fig. 1 is an overall system diagram of a current tracking control method of a virtual synchronous machine according to the present invention, fig. 2 is an active current control diagram of a current tracking control method of a virtual synchronous machine according to an embodiment of the present invention, and fig. 3 is a reactive current control diagram of a current tracking control method of a virtual synchronous machine according to an embodiment of the present invention;
the embodiment discloses a virtual synchronous machine current tracking control method, which comprises the following steps:
setting the active current of the virtual synchronous machine to be a set value I pref Actual active current I with virtual synchronous machine p Performing difference to obtain an active current difference, and taking the active current difference as mechanical active input of a virtual synchronous machine rotor motion equation;
constructing a rotor motion equation of a virtual synchronous machine, carrying out closed loop link with an integral link 1/Js as a forward channel and an output signal as a negative feedback channel through a proportional link D on the mechanical active input, and then carrying out rated angular frequency omega g Summing, obtaining the internal potential angle theta through a unit integral link vsc ；
Setting the reactive current set value I of the virtual synchronous machine qref Actual reactive current I with virtual synchronous machine q Obtaining reactive current difference by making difference, and taking the reactive current difference as G QR Input of link, and voltage of grid-connected pointModulus U om Summing to obtain an internal potential amplitude E ref Wherein G is QR The link is a PI controller;
referring to FIG. 5, the internal potential angle θ vsc And internal potential amplitude E ref Directly carrying out coordinate transformation to obtain the output voltage e of the virtual synchronous machine vscref_α And e vscref_β ；
Alternatively referring to FIG. 6, the internal potential angle θ vsc And internal potential amplitude E ref And grid-connected point voltage u od And u oq Make difference via G VAC Step (2) of adding voltage feedforward to obtain virtual synchronous machine output voltage e vscref_α And e vscref_β Wherein G is VAC The link is a PI controller.
Example two
Referring to fig. 4, fig. 4 is an active current and reactive current obtaining chart of a current tracking control method of a virtual synchronous machine according to a second embodiment of the invention;
the embodiment is based on embodiment one, and in steady state, the active current set point I of the virtual synchronous machine pref By the active power set point P of the virtual synchronous machine ref And grid-connected point voltage value U om Dividing and calculating to obtain a reactive current set value I of the virtual synchronous machine qref Directly given as 0.
Example III
The embodiment is based on the first embodiment, and the virtual synchronous reactive current set value I is during fault crossing qref Voltage value U from grid-connected point om According to the grid connection requirement, the active current set value I of the virtual synchronous machine is obtained by calculation pref By the active power set point P of the virtual synchronous machine ref And grid-connected point voltage value U om Dividing and calculating to obtain; active current set value I of the virtual synchronous machine qref And reactive current set point I qref The sum of the magnitudes of (1) does not exceed the upper virtual synchronous machine current limit.
Example IV
The present embodiment is based on embodiment one, in which the actual active current I pq The active current of the power grid is actually injected into the virtual synchronous machine, and the actual reactive current I q Actually injecting reactive current of a power grid into the virtual synchronous machine;
when a motion equation of the virtual synchronous machine rotor is constructed, the integral link 1/Js is used as a forward channel to correspond to a rotational inertia link of the virtual synchronous machine rotor, and the closed loop link with an output signal as a negative feedback channel through a proportional link D corresponds to a damping link of the virtual synchronous machine rotor;
the PI controller is a proportional plus integral regulator, and can eliminate errors given by direct current.
Example five
The present embodiment is based on embodiment one, in which the internal potential amplitude E ref Voltage value U through grid-connected point om And adding the output of the reactive current deviation PI controller to obtain the reactive current tracking speed given by the reactive current and the reactive current tracking precision.
Example six
The present embodiment is based on embodiment one, in which the internal potential amplitude E ref And an internal potential angle theta vsc Can be directly subjected to coordinate transformation and used as an input of a PWM wave generator. The voltage difference between the voltage of the virtual synchronous machine and the voltage of the grid-connected point can be made, and the voltage feedforward is added through the PI controller to serve as the input of the PWM wave generator.
Claims (5)
1. The virtual synchronous machine current tracking control method is characterized by comprising the following steps of:
setting the active current of the virtual synchronous machine to be I pref Actual active current I with virtual synchronous machine p Performing difference to obtain an active current difference, and taking the active current difference as mechanical active input of a virtual synchronous machine rotor motion equation;
constructing a virtual synchronous machine rotor motion equation, wherein the mechanical active input is processed by a process of taking an integral link 1/Js as a forward channel and an output signal is processed by a process of taking a proportion link D as a negativeClosed loop link of feedback channel, and rated angular frequency omega g Summing, obtaining the internal potential angle theta through a unit integral link vsc ；
Reactive current set value I of virtual synchronous machine qref Actual reactive current I with virtual synchronous machine q Obtaining reactive current difference by making difference, and taking the reactive current difference as G QR Input of link, and voltage module value U of grid-connected point om Summing to obtain an internal potential amplitude E ref Wherein G is QR The link is a PI controller;
the internal potential angle theta vsc And internal potential amplitude E ref Directly carrying out coordinate transformation to obtain the output voltage e of the virtual synchronous machine vscref_α And e vscref_β The method comprises the steps of carrying out a first treatment on the surface of the Or the internal potential angle theta vsc And internal potential amplitude E ref And grid-connected point voltage u od And u oq Make difference via G VAC Step (2) of adding voltage feedforward to obtain virtual synchronous machine output voltage e vscref_α And e vscref_β Wherein G is VAC The link is a PI controller;
in steady state, the active current set value I of the virtual synchronous machine pref By the active power set point P of the virtual synchronous machine ref And grid-connected point voltage value U om Dividing and calculating to obtain a reactive current set value I of the virtual synchronous machine qref Directly given as 0;
during fault ride-through, the virtually synchronous reactive current setpoint I qref Voltage value U from grid-connected point om According to the grid connection requirement, the active current set value I of the virtual synchronous machine is obtained by calculation pref By the active power set point P of the virtual synchronous machine ref And grid-connected point voltage value U om Dividing and calculating to obtain; active current set value I of the virtual synchronous machine qref And reactive current set point I qref The sum of the magnitudes of the current of the virtual synchronous machine does not exceed the upper limit;
the internal potential amplitude E ref Voltage value U through grid-connected point om And adding the output of the reactive current deviation PI controller.
2. The virtual synchronous machine current tracking control method according to claim 1, wherein the actual active current I pq The active current of the power grid is actually injected into the virtual synchronous machine, and the actual reactive current I q Reactive current of the power grid is actually injected into the virtual synchronous machine.
3. The method according to claim 1, wherein when the motion equation of the virtual synchronous machine rotor is constructed, the integration link 1/Js is used as a forward channel corresponding to the moment of inertia of the virtual synchronous machine rotor, and the closed loop link with the output signal passing through the proportion link D is used as a negative feedback channel corresponding to the damping link of the virtual synchronous machine rotor.
4. The virtual synchronous machine current tracking control method of claim 1, wherein the PI controller is a proportional plus integral regulator.
5. The virtual synchronous machine current tracking control method of claim 1, wherein the virtual synchronous machine output voltage e vscref_α And e vscref_β As input to the PWM wave generator.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002305900A (en) * | 2001-04-02 | 2002-10-18 | Okuma Corp | Control device for synchronous motor |
| TW201340584A (en) * | 2012-03-16 | 2013-10-01 | cheng-kai Lin | A predictive current control method for interior permanent magnet synchronous motors and synchronous reluctance motors based on extended back-EMF estimation |
| CN105896614A (en) * | 2016-04-12 | 2016-08-24 | 许继集团有限公司 | Photovoltaic inverter steady-state voltage balance control method and system thereof |
| CN114400718A (en) * | 2021-12-30 | 2022-04-26 | 深圳市禾望电气股份有限公司 | Active power tracking control method for virtual synchronous machine |
| CN115021602A (en) * | 2022-05-25 | 2022-09-06 | 三江学院 | Virtual synchronous machine-based double-loop model prediction method for three-level grid-connected inverter |
-
2022
- 2022-10-13 CN CN202211252783.3A patent/CN115579872B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002305900A (en) * | 2001-04-02 | 2002-10-18 | Okuma Corp | Control device for synchronous motor |
| TW201340584A (en) * | 2012-03-16 | 2013-10-01 | cheng-kai Lin | A predictive current control method for interior permanent magnet synchronous motors and synchronous reluctance motors based on extended back-EMF estimation |
| CN105896614A (en) * | 2016-04-12 | 2016-08-24 | 许继集团有限公司 | Photovoltaic inverter steady-state voltage balance control method and system thereof |
| CN114400718A (en) * | 2021-12-30 | 2022-04-26 | 深圳市禾望电气股份有限公司 | Active power tracking control method for virtual synchronous machine |
| CN115021602A (en) * | 2022-05-25 | 2022-09-06 | 三江学院 | Virtual synchronous machine-based double-loop model prediction method for three-level grid-connected inverter |
Non-Patent Citations (1)
| Title |
|---|
| 周娟等.并联有源电力滤波器电流预测控制及误差分析.电力电子技术.2018,第52卷(第12期),115-118. * |
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