CN106533289A - Non-linear voltage control method and system - Google Patents
Non-linear voltage control method and system Download PDFInfo
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- CN106533289A CN106533289A CN201610801549.XA CN201610801549A CN106533289A CN 106533289 A CN106533289 A CN 106533289A CN 201610801549 A CN201610801549 A CN 201610801549A CN 106533289 A CN106533289 A CN 106533289A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P9/00—Arrangements for controlling electric generators for the purpose of obtaining a desired output
- H02P9/14—Arrangements for controlling electric generators for the purpose of obtaining a desired output by variation of field
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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
- H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
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- Y02E40/30—Reactive power compensation
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Abstract
The invention discloses a non-linear voltage control method and system. The non-linear voltage control method includes the steps: according to a control system of an analog synchronous generator, determining a computational formula about state variables, wherein the state variables include an angular frequency and a power angle; converting a non-linear system model into a linear system model through coordinate transformation; and solving the optimum control rate of the terminal voltage of the analog synchronous generator in the linear system model, back-substituting the optimum control rate of the terminal voltage in the linear system to the non-linear system, and utilizing the optimum control rate of the terminal voltage of the analog synchronous generator in the non-linear system to regulate and control the amplitude of the terminal voltage of the analog synchronous generator so as to alleviate oscillation of the system during the transient process. The non-linear voltage control method and system takes regard of the influence of frequency, power angle, line impedance and moment of inertia on the terminal voltage of the analog synchronous generator while controlling the terminal voltage of the analog synchronous generator, thus alleviating oscillation of the system during the transient process, improving the system dynamic performance and improving the stability of system.
Description
Technical Field
The invention relates to the field of power systems, in particular to a nonlinear voltage control method and system.
Background
In order to alleviate the problems of shortage of fossil energy, serious environmental pollution and the like, renewable energy power generation mode is receiving wide attention. Electric energy generated by renewable energy sources comprises direct current and alternating current with various frequencies, and needs to be connected with the grid through an inverter. Since the grid-connected inverter is a static device without inertia and damping, the system stability is threatened. The Virtual Synchronous Generator (VSG) can simulate the operation mechanism of the synchronous generator, provides inertia and damping for the system, and can be used as an effective means for renewable energy power generation grid connection. The VSG mainly simulates droop control and inertia control of the synchronous generator, active frequency and reactive voltage control are decoupled, and the VSG is enabled to show good characteristics in steady-state operation by the aid of the control means. However, when a fault occurs, the VSG cannot weaken system oscillation, improve dynamic response, and improve system stability by means of additional excitation control and the like, as in a real synchronous generator.
Disclosure of Invention
The invention aims to provide a nonlinear voltage control method and a nonlinear voltage control system, which can control the terminal voltage of a virtual synchronous generator, thereby achieving the purposes of slowing down the oscillation of the system in the transient process and improving the dynamic response process.
In order to achieve the purpose, the invention provides the following scheme:
a method of nonlinear voltage control, the method comprising:
determining a calculation formula about state quantities according to a control system of a virtual synchronous generator to obtain a nonlinear system model of the control system, wherein the state quantities comprise angular frequency and power angle of the virtual synchronous generator;
converting the nonlinear system model into a linear system model through coordinate change;
solving the optimal control rate of the terminal voltage of the virtual synchronous generator in the linear system model to obtain the optimal control rate of the terminal voltage in the linear system;
replacing the optimal control rate of the terminal voltage in the linear system into the nonlinear system to obtain the optimal control rate of the terminal voltage of the virtual synchronous generator in the nonlinear system;
and regulating and controlling the amplitude of the voltage of the virtual synchronous motor by utilizing the optimal control rate of the voltage of the virtual synchronous generator in the nonlinear system so as to slow down the oscillation of the system in the transient process.
Optionally, the determining a calculation formula about the state quantity according to the control system of the virtual synchronous generator to obtain a nonlinear system model of the control system specifically includes:
determining a calculation formula of a control process according to each control link in a control circuit of the control system, the input torque of the virtual synchronous generator and the electromagnetic torque in the control system;
acquiring the electromagnetic torqueWherein E is the terminal voltage of the virtual synchronous engine, U is the network voltage, XLIs line impedance, is the power angle of the virtual synchronous generator, and omega is the angular frequency of the virtual synchronous generator;
will be provided withIs brought into the calculation formula of the control process to obtain a formula about the state quantityWherein, the terminal voltage E of the virtual synchronous generator is a control variable, X is the state quantity,as a derivative of the state quantity, X ═ ω]T，
Optionally, the converting the nonlinear system model into a linear system model through coordinate change specifically includes:
in non-linear systemsConverting into linear system by coordinate transformation to obtainWherein Z is a state variable in a linear system,is the derivative of the state variable in the linear system, A is the coefficient matrix of the state variable coefficient matrix, B is the coefficient matrix of the corresponding controlled variable, v is the optimal control rate of the terminal voltage of the linear system,
optionally, the solving of the optimal control rate of the terminal voltage of the virtual synchronous generator in the linear system model to obtain the optimal control rate of the terminal voltage in the linear system includes:
performance index formula for obtaining optimal control rate of linear systemWherein Q and R are symmetric positive definite weight matrices;
according to said formulaAnd solving a linear optimal control rate v by using a linear optimal control algorithm.
A non-linear voltage control system, the system comprising:
the state quantity calculation formula determination unit is used for determining a calculation formula related to state quantity according to a control system of the virtual synchronous generator to obtain a nonlinear system model of the control system, wherein the state quantity comprises angular frequency and a power angle of the virtual synchronous generator;
the linear system model conversion unit is used for converting the nonlinear system model into a linear system model through coordinate change;
the linear system optimal control rate calculation unit is used for solving the virtual synchronous generator terminal voltage optimal control rate of the linear system model to obtain the optimal control rate of the terminal voltage in the linear system;
the nonlinear system optimal control rate calculation unit is used for replacing the optimal control rate of the terminal voltage in the linear system back to the nonlinear system to obtain the optimal control rate of the terminal voltage of the virtual synchronous generator in the nonlinear system;
and the terminal voltage control unit is used for regulating and controlling the amplitude of the virtual synchronous motor terminal voltage by utilizing the optimal control rate of the virtual synchronous generator terminal voltage in the nonlinear system so as to slow down the system oscillation in the transient process.
Optionally, the state quantity calculation formula determining unit specifically includes:
a first state quantity calculation formula determination subunit, configured to determine a calculation formula of a control process according to each control link in a control circuit of the control system, an input torque of the virtual synchronous generator, and an electromagnetic torque in the control system;
an electromagnetic torque acquisition subunit for acquiring the electromagnetic torque, the electromagnetic torqueWherein E is the terminal voltage of the virtual synchronous engine, U is the network voltage, XLIs line impedance, is the power angle of the virtual synchronous generator, and omega is the angular frequency of the virtual synchronous generator;
a second state quantity calculation formula determination subunit for determining the state quantity of the second phaseIs brought into the calculation formula of the control process to obtain a formula about the state quantityWherein, the terminal voltage E of the virtual synchronous generator is a control variable, X is the state quantity,as a derivative of the state quantity, X ═ ω]T，
Optionally, the linear system model conversion unit specifically includes:
linear system model converter unit for converting in a non-linear systemConverting into linear system by coordinate transformation to obtainWherein Z is a state variable in a linear system,is the derivative of the state variable in the linear system, A is the coefficient matrix of the state variable coefficient matrix, B is the coefficient matrix of the corresponding controlled variable, v is the optimal control rate of the terminal voltage of the linear system,
optionally, the linear system optimal control rate calculating unit specifically includes:
a performance index formula obtaining subunit, configured to obtain a performance index formula for obtaining an optimal control rate of the linear systemWherein Q and R are symmetric positive definite weight matrices;
a linear system optimal control rate calculation subunit for calculating the optimal control rate according to the formulaAnd solving a linear optimal control rate v by using a linear optimal control algorithm.
According to the specific embodiment provided by the invention, the invention discloses the following technical effects: the invention introduces parameters such as frequency, power angle, line impedance, rotational inertia and the like to regulate and control the terminal voltage of the virtual synchronous generator, so that the control of the terminal voltage is related to voltage deviation and reactive deviation, and the influence of physical quantity in other transient processes is also accurately reflected. And (3) solving the linear optimal control rate by linearizing the nonlinear system, and replacing the linear optimal control rate into the original system to obtain the optimal control rate under the nonlinear system. Therefore, the system oscillation in the transient process is slowed down, the dynamic performance of the system is improved, and the stability of the system is improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.
FIG. 1 is a basic topology of a virtual synchronous generator;
FIG. 2 is a schematic diagram of a conventional virtual synchronous generator voltage control;
FIG. 3 is a schematic diagram illustrating a control flow of terminal voltage of a virtual synchronous generator according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of a virtual synchronous generator active-frequency control system;
fig. 5 is a schematic structural diagram of a control system for terminal voltage of a virtual synchronous generator according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention aims to provide a nonlinear voltage control method and a nonlinear voltage control system, which can control the terminal voltage of a virtual synchronous generator, thereby achieving the purposes of slowing down the oscillation of the system in the transient process and improving the dynamic response process.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.
Fig. 1 is a basic topology structure of a virtual synchronous generator, and as shown in fig. 1, the virtual synchronous generator includes 5 sub-modules of a three-phase inverter, a filter, grid-connected port power calculation, a VSG control algorithm, and SVPWM modulation. The Virtual Synchronous Generator (VSG) enables an inverter to have the characteristics similar to those of a synchronous generator by simulating the mechanical characteristics and the electromagnetic characteristics of the synchronous generator so as to achieve the aim of providing inertia support and damping support for a power grid.
As shown in fig. 1, e ═ eaebec]T，u＝[uaubuc]T，i＝[iaibic]TThe three-phase induced electromotive force, the output end voltage and the grid-connected current of the virtual synchronous generator are respectively; rsAnd LsRespectively indicating a virtual stator armature resistance and a synchronous inductance; peAnd QeRespectively, the active power and the reactive power output by the VSG.
As shown in fig. 1, the virtual synchronous generator mainly includes a main circuit and a control system. The main circuit is a conventional grid-connected inverter topology and comprises a renewable energy source side (which can be regarded as a prime mover), a DC/AC converter, a filter circuit and the like (corresponding to the electromechanical energy conversion process of the synchronous generator); the control system is the core for realizing the virtual synchronous generator and mainly comprises a virtual synchronous generator body model and a control algorithm, wherein the virtual synchronous generator body model is mainly used for simulating the electromagnetic relation and the mechanical motion of the synchronous generator in terms of mechanism, and the control algorithm is mainly used for simulating the characteristics of active frequency modulation, reactive voltage regulation and the like of the synchronous generator in terms of external characteristics.
Fig. 2 is a schematic diagram of a conventional virtual synchronous generator voltage control, as shown in fig. 2, in the conventional VSG control, a terminal voltage thereof is determined by a deviation between a set voltage and an actual terminal voltage and a deviation between a set reactive power and an actual output reactive power.
As shown in fig. 2, the terminal voltage expression of VSG isFrom this, it is understood that the terminal voltage of the VSG is affected only by the reactive power deviation and the voltage deviation. In an actual synchronous generator, the terminal voltage is determined by the exciting current, and the exciting current is influenced by a plurality of physical quantities such as frequency, power angle, output current and the like besides active and reactive power, so that the amplitude of the voltage changes in real time in the transient process, the dynamic response can be improved, and the system stability can be improved. However, current VSGs have not implemented this control strategy, resulting in its beingThe response during transients is not ideal.
Renewable energy is mainly connected to the power grid through VSG, the current VSG mainly adopts droop control or inertia control, active frequency control and reactive voltage control are decoupled, the control mode can ensure that the VSG can safely and stably operate in a steady state, and when a fault occurs, the system is severely oscillated, dynamic response is deteriorated, and the system stability is threatened.
Fig. 3 is a schematic diagram of a control flow of the terminal voltage of the virtual synchronous generator according to the embodiment of the present invention, and as shown in fig. 3, the control steps of the terminal voltage of the virtual synchronous generator are as follows:
step 301: determining a calculation formula about state quantities according to a control system of a virtual synchronous generator to obtain a nonlinear system model of the control system, wherein the state quantities comprise angular frequency and power angle of the virtual synchronous generator;
step 302: converting the nonlinear system model into a linear system model through coordinate change;
step 303: solving the optimal control rate of the voltage at the end of the virtual synchronous generator on the linear system model to obtain the optimal control rate of the voltage at the end in the linear system;
step 304: replacing the optimal control rate of the terminal voltage in the linear system into the nonlinear system to obtain the optimal control rate of the terminal voltage of the virtual synchronous generator in the nonlinear system;
step 305: and regulating and controlling the amplitude of the voltage of the virtual synchronous motor by utilizing the optimal control rate of the voltage of the virtual synchronous generator in the nonlinear system so as to slow down the oscillation of the system in the transient process.
In step 301, the method specifically includes: and determining a calculation formula of a control process according to each control link in a control circuit of the control system, the input torque of the virtual synchronous generator and the electromagnetic torque in the control system.
Acquiring the electromagnetic torqueWherein E is the terminal voltage of the virtual synchronous engine, U is the network voltage, XLIs line impedance, is the power angle of the virtual synchronous generator, and omega is the angular frequency of the virtual synchronous generator;
will be provided withAnd the calculation formula related to the state quantity is obtained by being brought into the calculation formula of the control process.
FIG. 4 is a schematic diagram of an active-frequency control system of a virtual synchronous generator, shown in FIG. 4, TmAnd TeRepresenting the VSG input torque and the electromagnetic torque, respectively. Omega is the angular frequency of the virtual synchronous generator, omega0For the rated angular frequency of the power grid, D and J are respectively the damping coefficient and the virtual inertia of the VSG. According to the control system provided in fig. 4, and the method provided in step 301, a calculation formula for the control system with respect to the state quantity can be obtainedWherein, the terminal voltage E of the virtual synchronous generator is a control variable, X is the state quantity,as a derivative of the state quantity, X ═ ω]T，
In step 302, in a non-linear systemConverting into linear system by coordinate transformation to obtainWherein Z is a state variable in a linear system,is the derivative of the state variable in the linear system, A is the coefficient matrix of the state variable coefficient matrix, B is the coefficient matrix of the corresponding controlled variable, v is the optimal control rate of the terminal voltage of the linear system,
in step 303, a performance index formula for the linear system to obtain the optimal control rate is obtainedWherein Q and R are symmetric positive definite weight matrices;
according to said formulaAnd solving a linear optimal control rate v by using a linear optimal control algorithm.
Before the coordinate transformation is performed, it is first checked whether the system can be accurately linearized. The essential conditions for an affine nonlinear system to be able to be linearized accurately are:
1) near the equilibrium point, the matrixIs unchanged and is equal to the order of the system; the equilibrium point is the point where the system initially operates steadily, where ω is ω ═ ω0，＝0The corresponding point is set to be the point of the corresponding point,
whereinRefer to the n-th order Lie brackets of g in the f direction.
2) Vector fieldInvolution at the balance point.
Since the system (3) is a second order system, only its first order lie derivative needs to be calculated, i.e.
Through calculation, the system can be accurately linearized in a region omega {, omega | ≠ 0, pi }. For a system that is actually operating, the power angle satisfies 0 < pi, so it can be considered that the system can be accurately linearized.
After the system can be accurately linearized through inspection, the specific steps of converting a nonlinear system into a linear system are carried out:
1) let D1＝{g}，D2＝{g，adfg, two linearly independent vector fields are selectedMake it satisfyOne set of choices that meets the requirements is:
2) calculating a mapping X ═ F (W) corresponding to the equationX0＝[0,ω0]T
Wherein, w1And w2For the state variable under the new mapping,is represented by X0As an initial value, w2 as an independent variable, andis the integral of the derivative, i.e.
Is shown inAs an initial value, w1As an independent variable, withIs the integral of the derivative, from which it is known
Is inversely mapped as
3) By calculation at F-1Derived mapping of f (X) belowTo obtain f(0)(w)，f(0)(w) is followed by R1The required vector field is transformed.
First inverse mapping F-1Jacobian matrix of
Thus, can obtain
Systemizing a source into a linear system
Computing a transformation R1
Wherein,andis R1A state variable under transformation.
Defining a transformation T as
From this, obtain
Wherein,andis an intermediate variable of the Z transform.
Definition of
z1＝w2＝-0
The linear system after transformation can be obtained as
Wherein Z is [ Z ]1,z2]TIs a state variable in a linear system, A is a coefficient matrix of a state variable coefficient matrix, B is a coefficient matrix of a corresponding control quantity, and the values of the coefficient matrices are respectively
Solving the optimal control rate of the linearized system, and firstly establishing the performance index of the linearized system
Where Q and R are symmetric positive definite weight matrices, it is generally desirable to
The linear optimal control rate v can be obtained by a linear optimal control algorithm, so that the optimal control rate of the performance index is
v＝-R-1BTP*Z
Wherein P is a symmetric constant matrix and is the solution of Riccati equation, namely P satisfies
ATP+PA-PBR-1BTP+Q＝0
Thus, it can be seen that
v*＝-z1-1.73z2
The result is substituted back to the original system, and the optimal control rate corresponding to the original nonlinear system is obtained as
The control method of the terminal voltage of the virtual synchronous generator introduces parameters such as frequency, power angle, line impedance, rotational inertia and the like to regulate and control the terminal voltage of the virtual synchronous generator, so that the control of the terminal voltage is related to voltage deviation and reactive deviation, and the influence of physical quantity in other transient processes is also accurately reflected. And (3) solving the linear optimal control rate by linearizing the nonlinear system, and replacing the linear optimal control rate into the original system to obtain the optimal control rate under the nonlinear system. Therefore, the system oscillation in the transient process is slowed down, the dynamic performance of the system is improved, and the stability of the system is improved.
To achieve the above object, the present invention further provides a nonlinear voltage control system, fig. 5 is a schematic structural diagram of a control system for terminal voltage of a virtual synchronous generator according to an embodiment of the present invention, and as shown in fig. 5, the system includes:
the state quantity calculation formula determination unit is used for determining a calculation formula related to state quantity according to a control system of the virtual synchronous generator to obtain a nonlinear system model of the control system, wherein the state quantity comprises angular frequency and a power angle of the virtual synchronous generator;
the linear system model conversion unit is used for converting the nonlinear system model into a linear system model through coordinate change;
the linear system optimal control rate calculation unit is used for solving the virtual synchronous generator terminal voltage optimal control rate of the linear system model to obtain the optimal control rate of the terminal voltage in the linear system;
the nonlinear system optimal control rate calculation unit is used for replacing the optimal control rate of the terminal voltage in the linear system back to the nonlinear system to obtain the optimal control rate of the terminal voltage of the virtual synchronous generator in the nonlinear system;
and the terminal voltage control unit is used for regulating and controlling the amplitude of the virtual synchronous motor terminal voltage by utilizing the optimal control rate of the virtual synchronous generator terminal voltage in the nonlinear system so as to slow down the system oscillation in the transient process.
The state quantity calculation formula determination unit specifically includes:
a first state quantity calculation formula determination subunit, configured to determine a calculation formula of a control process according to each control link in a control circuit of the control system, an input torque of the virtual synchronous generator, and an electromagnetic torque in the control system;
an electromagnetic torque acquisition subunit for acquiring the electromagnetic torque, the electromagnetic torqueWherein E is the terminal voltage of the virtual synchronous engine, U is the network voltage, XLIs line impedance, is the power angle of the virtual synchronous generator, and omega is the virtual synchronous generatorAn angular frequency;
a second state quantity calculation formula determination subunit for determining the state quantity of the second phaseIs brought into the calculation formula of the control process to obtain a formula about the state quantityWherein, the terminal voltage E of the virtual synchronous generator is a control variable, X is the state quantity,as a derivative of the state quantity, X ═ ω]T，
The linear system model conversion unit specifically comprises:
linear system model converter unit for converting in a non-linear systemConverting into linear system by coordinate transformation to obtainWherein Z is a state variable in a linear system,is the derivative of the state variable in the linear system, A is the coefficient matrix of the state variable coefficient matrix, B is the coefficient matrix of the corresponding controlled variable, v is the optimal control rate of the terminal voltage of the linear system,
the linear system optimal control rate calculation unit specifically includes:
a performance index formula obtaining subunit, configured to obtain a performance index formula for obtaining an optimal control rate of the linear systemWherein Q and R are symmetric positive definite weight matrices;
a linear system optimal control rate calculation subunit for calculating the optimal control rate according to the formulaAnd solving a linear optimal control rate v by using a linear optimal control algorithm.
The terminal voltage (terminal voltage) control system of the virtual synchronous generator considers the influence of parameters such as frequency, power angle, line impedance, rotational inertia and the like on the terminal voltage of the virtual synchronous generator, slows down the oscillation of the system in the transient process, improves the dynamic performance of the system and improves the stability of the system.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. For the system disclosed by the embodiment, the description is relatively simple because the system corresponds to the method disclosed by the embodiment, and the relevant points can be referred to the method part for description.
The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.
Claims (8)
1. A method of nonlinear voltage control, the method comprising:
determining a calculation formula about state quantities according to a control system of a virtual synchronous generator to obtain a nonlinear system model of the control system, wherein the state quantities comprise angular frequency and power angle of the virtual synchronous generator;
converting the nonlinear system model into a linear system model through coordinate change;
solving the optimal control rate of the terminal voltage of the virtual synchronous generator in the linear system model to obtain the optimal control rate of the terminal voltage in the linear system;
replacing the optimal control rate of the terminal voltage in the linear system into the nonlinear system to obtain the optimal control rate of the terminal voltage of the virtual synchronous generator in the nonlinear system;
and regulating and controlling the amplitude of the voltage of the virtual synchronous motor by utilizing the optimal control rate of the voltage of the virtual synchronous generator in the nonlinear system so as to slow down the oscillation of the system in the transient process.
2. The method according to claim 1, wherein the determining a calculation formula about the state quantity according to the control system of the virtual synchronous generator to obtain the nonlinear system model of the control system specifically comprises:
determining a calculation formula of a control process according to each control link in a control circuit of the control system, the input torque of the virtual synchronous generator and the electromagnetic torque in the control system;
acquiring the electromagnetic torqueWherein E is the terminal voltage of the virtual synchronous engine, U is the network voltage, XLIs line impedance, is the power angle of the virtual synchronous generator, and omega is the angular frequency of the virtual synchronous generator;
will be provided withIs brought into the calculation formula of the control process to obtain a formula about the state quantityWherein, the terminal voltage E of the virtual synchronous generator is a control variable, X is the state quantity,as a derivative of the state quantity, X ═ ω]T，
3. The method according to claim 1, wherein the converting the nonlinear system model into a linear system model through coordinate transformation specifically comprises:
in non-linear systemsConverting into linear system by coordinate transformation to obtainWherein Z is a state variable in a linear system,is the derivative of the state variable in the linear system, A is the coefficient matrix of the state variable coefficient matrix, B is the coefficient matrix of the corresponding controlled variable, v is the optimal control rate of the terminal voltage of the linear system,
4. the method according to claim 1, wherein the solving for the optimal control rate of the terminal voltage of the virtual synchronous generator in the linear system model to obtain the optimal control rate of the terminal voltage in the linear system includes:
performance index formula for obtaining optimal control rate of linear systemWherein Q and R are symmetric positive definite weight matrices;
according to said formulaAnd solving a linear optimal control rate v by using a linear optimal control algorithm.
5. A non-linear voltage control system, the system comprising:
the state quantity calculation formula determination unit is used for determining a calculation formula related to state quantity according to a control system of the virtual synchronous generator to obtain a nonlinear system model of the control system, wherein the state quantity comprises angular frequency and a power angle of the virtual synchronous generator;
the linear system model conversion unit is used for converting the nonlinear system model into a linear system model through coordinate change;
the linear system optimal control rate calculation unit is used for solving the virtual synchronous generator terminal voltage optimal control rate of the linear system model to obtain the optimal control rate of the terminal voltage in the linear system;
the nonlinear system optimal control rate calculation unit is used for replacing the optimal control rate of the terminal voltage in the linear system back to the nonlinear system to obtain the optimal control rate of the terminal voltage of the virtual synchronous generator in the nonlinear system;
and the terminal voltage control unit is used for regulating and controlling the amplitude of the virtual synchronous motor terminal voltage by utilizing the optimal control rate of the virtual synchronous generator terminal voltage in the nonlinear system so as to slow down the system oscillation in the transient process.
6. The system according to claim 5, wherein the state quantity calculation formula determination unit specifically includes:
a first state quantity calculation formula determination subunit, configured to determine a calculation formula of a control process according to each control link in a control circuit of the control system, an input torque of the virtual synchronous generator, and an electromagnetic torque in the control system;
electromagnetic torque acquisition subunit, usingUpon obtaining the electromagnetic torque, the electromagnetic torqueWherein E is the terminal voltage of the virtual synchronous engine, U is the network voltage, XLIs line impedance, is the power angle of the virtual synchronous generator, and omega is the angular frequency of the virtual synchronous generator;
a second state quantity calculation formula determination subunit for determining the state quantity of the second phaseIs brought into the calculation formula of the control process to obtain a formula about the state quantityWherein, the terminal voltage E of the virtual synchronous generator is a control variable, X is the state quantity,as a derivative of the state quantity, X ═ ω]T，
7. The system according to claim 5, wherein the linear system model transformation unit specifically comprises:
linear system model converter unit for converting in a non-linear systemConverting into linear system by coordinate transformation to obtainWherein Z is a state variable in a linear system,is the derivative of the state variable in the linear system, A is the coefficient matrix of the state variable coefficient matrix, B is the coefficient matrix of the corresponding controlled variable, v is the optimal control rate of the terminal voltage of the linear system,
8. the system according to claim 5, wherein the linear system optimal control rate calculation unit specifically includes:
a performance index formula obtaining subunit, configured to obtain a performance index formula for obtaining an optimal control rate of the linear systemWherein Q and R are symmetric positive definite weight matrices;
a linear system optimal control rate calculation subunit for calculating the optimal control rate according to the formulaAnd solving a linear optimal control rate v by using a linear optimal control algorithm.
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| CN201610801549.XA CN106533289B (en) | 2016-09-05 | 2016-09-05 | A kind of non-linear voltage control method and system |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107346885A (en) * | 2017-08-24 | 2017-11-14 | 华北电力大学（保定） | A kind of DC/DC bi-directional inverters stable DC busbar voltage method for optimally controlling |
| CN109301858A (en) * | 2018-09-07 | 2019-02-01 | 南昌大学 | A kind of control method based on adaptive Dynamic Programming optimization virtual synchronous machine photovoltaic combining inverter |
| CN111614112A (en) * | 2020-06-11 | 2020-09-01 | 内蒙古工业大学 | Virtual synchronous generator control method and system of matrix converter |
| US20210104964A1 (en) * | 2019-10-02 | 2021-04-08 | Schneider Electric Industries Sas | Adjustment of parameter values of a control rule of a generator |
| CN113193793A (en) * | 2021-03-18 | 2021-07-30 | 武汉科力源电气有限公司 | VSG technology-based synchronous motor back-to-back speed regulation method and related equipment |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
| CN104993521A (en) * | 2015-07-23 | 2015-10-21 | 国家电网公司 | Energy storage method based on virtual synchronization inversion control |
| CN105680714A (en) * | 2014-11-19 | 2016-06-15 | 国家电网公司 | Control method and device for output voltage of inverter |
| CN105826949A (en) * | 2016-05-20 | 2016-08-03 | 国网浙江省电力公司电力科学研究院 | Transient control method for controlling synchronous stability of virtual synchronous control inverter |
| CN105915140A (en) * | 2016-04-22 | 2016-08-31 | 广东电网有限责任公司电力科学研究院 | Decoupling control method based on virtual synchronous generator and decoupling control device thereof |
-
2016
- 2016-09-05 CN CN201610801549.XA patent/CN106533289B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105680714A (en) * | 2014-11-19 | 2016-06-15 | 国家电网公司 | Control method and device for output voltage of inverter |
| 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 |
| CN104993521A (en) * | 2015-07-23 | 2015-10-21 | 国家电网公司 | Energy storage method based on virtual synchronization inversion control |
| CN105915140A (en) * | 2016-04-22 | 2016-08-31 | 广东电网有限责任公司电力科学研究院 | Decoupling control method based on virtual synchronous generator and decoupling control device thereof |
| CN105826949A (en) * | 2016-05-20 | 2016-08-03 | 国网浙江省电力公司电力科学研究院 | Transient control method for controlling synchronous stability of virtual synchronous control inverter |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107346885A (en) * | 2017-08-24 | 2017-11-14 | 华北电力大学（保定） | A kind of DC/DC bi-directional inverters stable DC busbar voltage method for optimally controlling |
| CN109301858A (en) * | 2018-09-07 | 2019-02-01 | 南昌大学 | A kind of control method based on adaptive Dynamic Programming optimization virtual synchronous machine photovoltaic combining inverter |
| US20210104964A1 (en) * | 2019-10-02 | 2021-04-08 | Schneider Electric Industries Sas | Adjustment of parameter values of a control rule of a generator |
| CN111614112A (en) * | 2020-06-11 | 2020-09-01 | 内蒙古工业大学 | Virtual synchronous generator control method and system of matrix converter |
| CN113193793A (en) * | 2021-03-18 | 2021-07-30 | 武汉科力源电气有限公司 | VSG technology-based synchronous motor back-to-back speed regulation method and related equipment |
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