CN115149582A - Voltage stability analysis method for photovoltaic grid-connected power system based on monotonic system theory - Google Patents

Voltage stability analysis method for photovoltaic grid-connected power system based on monotonic system theory Download PDF

Info

Publication number
CN115149582A
CN115149582A CN202210723585.4A CN202210723585A CN115149582A CN 115149582 A CN115149582 A CN 115149582A CN 202210723585 A CN202210723585 A CN 202210723585A CN 115149582 A CN115149582 A CN 115149582A
Authority
CN
China
Prior art keywords
equation
voltage
formula
jacobian matrix
synchronous machine
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202210723585.4A
Other languages
Chinese (zh)
Inventor
倪秋龙
王波
朱晓杰
王晴
杨滢
周正阳
周靖皓
虞殷树
贺旭
朱耿
黄亮
陈东海
孙维真
石博隆
蔡振华
谢楚
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ningbo Power Supply Co of State Grid Zhejiang Electric Power Co Ltd
Original Assignee
Ningbo Power Supply Co of State Grid Zhejiang Electric Power Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ningbo Power Supply Co of State Grid Zhejiang Electric Power Co Ltd filed Critical Ningbo Power Supply Co of State Grid Zhejiang Electric Power Co Ltd
Priority to CN202210723585.4A priority Critical patent/CN115149582A/en
Publication of CN115149582A publication Critical patent/CN115149582A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—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
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
    • G06Q10/00—Administration; Management
    • G06Q10/06—Resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation modelling
    • G06Q10/063—Operations research, analysis or management
    • G06Q10/0639—Performance analysis of employees; Performance analysis of enterprise or organisation operations
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
    • G06Q50/00—Information and communication technology [ICT] specially adapted for implementation of business processes of specific business sectors, e.g. utilities or tourism
    • G06Q50/06—Energy or water supply
    • 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
    • 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
    • H02J3/16—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load by adjustment of reactive power
    • 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
    • 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
    • H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
    • H02J2203/10—Power transmission or distribution systems management focussing at grid-level, e.g. load flow analysis, node profile computation, meshed network optimisation, active network management or spinning reserve management
    • 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
    • H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
    • H02J2203/20—Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
    • 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
    • H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/20—The dispersed energy generation being of renewable origin
    • H02J2300/22—The renewable source being solar energy
    • H02J2300/24—The renewable source being solar energy of photovoltaic origin

Landscapes

  • Engineering & Computer Science (AREA)
  • Business, Economics & Management (AREA)
  • Human Resources & Organizations (AREA)
  • Power Engineering (AREA)
  • Economics (AREA)
  • Strategic Management (AREA)
  • Educational Administration (AREA)
  • Theoretical Computer Science (AREA)
  • Marketing (AREA)
  • Entrepreneurship & Innovation (AREA)
  • Health & Medical Sciences (AREA)
  • Tourism & Hospitality (AREA)
  • Physics & Mathematics (AREA)
  • General Business, Economics & Management (AREA)
  • General Physics & Mathematics (AREA)
  • Development Economics (AREA)
  • Public Health (AREA)
  • General Health & Medical Sciences (AREA)
  • Water Supply & Treatment (AREA)
  • Primary Health Care (AREA)
  • Game Theory and Decision Science (AREA)
  • Operations Research (AREA)
  • Quality & Reliability (AREA)
  • Supply And Distribution Of Alternating Current (AREA)

Abstract

The invention discloses a voltage stability analysis method of a photovoltaic grid-connected power system based on a monotone system theory. The method comprises the following steps: s1: dividing a power system dynamic equation into an element dynamic equation, a network equation and an interface equation, and providing a modular-based power system symbolic feature solving method; s2: solving the Jacobian matrix symbolic characteristic of a voltage subsystem of the power system based on the modular derivation method of S1; s3: based on a monotonous system theory and a small gain stability criterion of an interconnected monotonous system, the voltage stability of the power system is evaluated by taking the radius of a gain function Jacobian matrix spectrum as a quantitative evaluation index, and parameters are adjusted according to the index so as to improve the voltage stability of the system. The method well expounds the reactive voltage support cooperation relation between the generator sets based on the monotone dynamic system theory by utilizing the inherent mathematical characteristics of the electromechanical transient model of the power system and combining with the special matrix theory, and is favorable for further implementation of the coordination control design of the photovoltaic grid-connected system.

Description

Voltage stability analysis method for photovoltaic grid-connected power system based on monotonic system theory
Technical Field
The invention belongs to the field of voltage stability analysis and control of an electric power system, and particularly relates to a voltage stability analysis method of a photovoltaic grid-connected electric power system based on a monotonous system theory.
Background
Much effort and research has been devoted to analyzing the voltage stability of conventional power grids, including static voltage problems and dynamic voltage problems. So far, the static voltage problem is basically based on a tidal current algebraic equation to study the existence of sensitivity or voltage solution, and the voltage support strength of the power grid is judged according to a short-circuit ratio index. Time domain simulation is still the most efficient method in terms of dynamic voltage problems, but the structural characteristics of modern power systems are poorly understood. Compared with the traditional power system based on synchronous generators, the dynamic characteristics of the high-penetration new energy power system have more complex dynamic characteristics, and particularly, the dynamic characteristics have significant differences in the primary energy characteristics, the number types of components, the time scale and the like. Particularly, in the transition stage from the traditional power system to the modern power system with high penetration of new energy, various dynamic characteristics affect each other, and the dynamic process is particularly complex.
The new energy generator set needs to be connected to a power grid through a converter, and is mainly divided into a grid-following converter (GFL) and a grid-forming converter (GFM) according to different control modes. GFLs control the real and reactive power output by varying the injected current, with the external characteristics appearing as a controllable current source. The structure of the GFM is similar to the GFL, but the phase-locked loop is removed from the control structure and virtual inertia is added to simulate the swing equation of a synchronous generator. Therefore, the external characteristic of the GFM is similar to a controllable voltage source, the output power can be changed when the system is disturbed, the GFM directly participates in voltage and frequency control of a power grid, and partial scholars think that the GFM has voltage supporting capacity and can be directly connected to a passive power grid.
Because the reactive power regulation capability of most new energy source units such as wind power, photovoltaic and the like is insufficient, the voltage instability becomes one of the biggest threats to the safe operation of the power system, in order to better understand the nature of voltage stability in power systems, it is imperative to develop more efficient methods.
Disclosure of Invention
In order to solve the problems in the background art, the invention provides a photovoltaic grid-connected power system voltage stability analysis method based on a monotone system theory, and solves the problem of voltage stability analysis.
The invention adopts the following technical scheme:
step S1: dividing the dynamic equation of the power system into an element dynamic equation, a network equation and an interface equation, providing a modular-based method for solving symbolic features of an electric power system; the method comprises the following steps:
1.1 Divide the power system dynamic equations into three modular parts:
a) Dynamic equation of the element:
Figure BDA0003710110230000021
the vector field F only contains the state variable and the terminal voltage variable of the element;
b) Network equation:
Figure BDA0003710110230000022
right end terms are written uniformly a power injection form;
c) Interface equation of element and network: s = h (x, V) x ,V y ) Which is used to indicate the power injected into the network by each element.
Where x is the state variable of the element, V is the node voltage, V x And V y Respectively, xy components of port voltage of the element under a common coordinate system, S is power injected into a power system by the element, Y is a network admittance matrix, and an upper line represents the conjugation of a vector;
1.2 After the partial derivatives of the modules are obtained, a Jacobian matrix of the whole system can be obtained by using a chain type derivative rule:
Figure BDA0003710110230000023
in the formula:
Figure BDA0003710110230000024
and
Figure BDA0003710110230000025
directly solving by an element dynamic equation;
1.3)
Figure BDA0003710110230000026
and
Figure BDA0003710110230000027
the method is obtained through a simultaneous network equation and an interface equation, and comprises the following specific steps:
combining the network equation and the interface equation can obtain:
Figure BDA0003710110230000028
with the help of the chain rule, the above formula is used to calculate the partial derivative of x:
Figure BDA0003710110230000029
substituting the second formula in the above formula into the first formula to eliminate
Figure BDA00037101102300000210
Obtaining:
Figure BDA00037101102300000211
and using the following relationship:
Figure BDA0003710110230000031
substituting the substituted amino group into a substitution and finishing to obtain:
Figure BDA0003710110230000032
wherein j is a complex number.
Order:
Figure BDA0003710110230000033
and substituting and then taking conjugation to obtain an equation set:
Figure BDA0003710110230000034
solving to obtain:
Figure BDA0003710110230000035
substituting the formula in step 1.2 can obtain the Jacobian matrix of the system.
Step S2: based on the modular derivation method of the step S1, the Jacobian matrix symbolic characteristic of the voltage subsystem of the power system is obtained; the method comprises the following steps:
2.1 Determine the Jacobian matrix symbolic features of a monotonic system: for a monotonic nonlinear controlled system with an output:
Figure BDA0003710110230000036
wherein x represents a state variable, y represents an output variable, and v represents an input variable, and the Jacobian matrix has the following symbolic characteristics:
Figure BDA0003710110230000041
Figure BDA0003710110230000042
Figure BDA0003710110230000043
the monotonicity of the subsystem in the interconnected system can be conveniently judged by utilizing the symbolic characteristics of the Jacobian matrix, and the stability of the interconnected system can be judged by adopting a small-gain stability criterion when the subsystems meet the monotonous system condition.
2.2 Computing a Jacobian matrix of the transient potential of the synchronous machine: the dynamic equation of the synchronous machine voltage subsystem is as follows:
Figure BDA0003710110230000044
Figure BDA0003710110230000045
combining stator voltage equations:
Figure BDA0003710110230000046
and coordinate transformation:
V d ＝V x sinδ-V y cosδ
V q ＝V x cosδ+V y sinδ
obtaining a dynamic equation only containing voltage variables and state variables:
Figure BDA0003710110230000047
Figure BDA0003710110230000048
in the formula: t is a unit of d ′ 0 As open circuit time constant, E q ' transient potential after transient reactance, E fd Is an excitation voltage, x d And x' d Synchronous and transient reactances, V, respectively x And V y Xy component of the end voltage of the synchronous machine on a common coordinate axis, delta is rotor angle and T A As excitation time constant, K A For exciting amplification factor, V ref For exciting reference voltage, V t Is the synchronous machine terminal voltage. Further, the transient potential partial derivatives of the dynamic equation of the synchronous machine are obtained as follows:
Figure BDA0003710110230000049
according to the synchronous machine interface equation, namely the power injected into the power grid:
Figure BDA00037101102300000410
the derivation of the relative partial derivatives of the interface equation is as follows:
Figure BDA0003710110230000051
and (3) taking the load as constant impedance, merging the constant impedance into a network equation, and eliminating intermediate nodes by using Kron transformation to obtain an A matrix expression in the step 1.3:
Figure BDA0003710110230000052
in the formula: diag (. Circle.) denotes a diagonal matrix composed of bracketed elements, n is the number of synchronizer nodes, Y aug Re-merging the admittance matrix Y after Kron transformation into synchronous machine reactance
Figure BDA0003710110230000053
The power grid admittance matrix is approximate to a Laplace matrix, so that Y can be known according to the property of Kron transformation aug The approximation remains a laplacian matrix. The B and C matrix expression matrices are calculated as follows:
Figure BDA0003710110230000054
Figure BDA0003710110230000055
according to the property of the network admittance matrix, the element order of A is hundreds, the element of the conjugate inverse matrix is very small, and the order of magnitude is 10 -3 To 10 -2 Then, the order of magnitude of B element can be estimated to be between 1 and 10 according to the typical value of the synchronous machine, and then an approximate formula can be obtained:
Figure BDA0003710110230000056
Figure BDA0003710110230000057
obtaining:
Figure BDA0003710110230000058
substituting the expressions of A and C to obtain:
Figure BDA0003710110230000059
from the Laplace matrix property, Z is approximate to a full positive matrix, and the angle of the q axis of the synchronous machine relative to the reference machine can be made to be within +/-30 degrees by adjusting the reference phase, so that
Figure BDA00037101102300000510
The real part is much larger than the imaginary part, and the real parts are all larger than zero, then:
Figure BDA0003710110230000061
the non-diagonal elements of the method are all positive numbers, satisfying a monotonic system condition.
2.3 Solving a Jacobian matrix of transient potentials to the excitation system: solving a partial derivative term of an excitation system dynamic equation according to a synchronous machine dynamic equation:
Figure BDA0003710110230000062
the partial derivative of the excitation voltage of the synchronous machine to the transient potential is obtained according to the steps as follows:
Figure BDA0003710110230000063
it is known that
Figure BDA0003710110230000064
Is a non-negative matrix, and the real part is far larger than the imaginary part, V x Normally positive, the jacobian matrix that derives the excitation voltage with respect to the transient potential is a negative matrix, and thus the transient potential is the negative feedback signal input to the excitation system.
2.4 Solving a Jacobian matrix of the excitation system: in the interface equation, the injection power does not contain the excitation voltage variable, so that the Jacobian matrix of the excitation voltage to the excitation voltage is only connected with
Figure BDA0003710110230000065
The terms relate to, namely:
Figure BDA0003710110230000066
in the formula: t is A Is composed of T Ai Forming a diagonal matrix.
2.5 A Jacobian matrix is found for the excitation system to transient potentials: similarly, the Jacobian matrix of the transient potential to the excitation voltage is only AND
Figure BDA0003710110230000067
Are related to, i.e.
Figure BDA0003710110230000068
In the formula: t is a unit of d0 Is composed of T d0i Forming a diagonal matrix.
2.6 Computing the Jacobian matrix signature of the tracking network type current transformer (GFL): during electromechanical transients, it is generally assumed that the GFL is able to track the grid frequency in real time, thus ignoring the dynamics of the phase locked loop. The dynamic model in normal operation can be described as:
Figure BDA0003710110230000069
Figure BDA00037101102300000610
I d ＝K p (P ref -P pv )+x p
I q ＝K p (Q pv -Q ref )-x q
P pv ＝I d |V|，Q PV ＝-I q |V|
in the formula: k p And K i Respectively representing the amplification factor and time constant of the PI control, P ref And Q ref Reference value, P, representing output power pv And Q pv The table shows the output active and reactive power, x, of the GFL, respectively p And x q Respectively representing internal state variables, I, corresponding to active and reactive power d And I q Respectively, the components of the output current of the GFL on the dq axis, and | V | is the terminal voltage amplitude of the GFL. When the voltage stability is researched, the influence of active power is not considered, so that a dynamic equation and an interface equation of only a reactive control link are obtained after a current variable is eliminated:
Figure BDA0003710110230000071
Figure BDA0003710110230000072
the GFL equation partial derivatives are as follows:
Figure BDA0003710110230000073
Figure BDA0003710110230000074
Figure BDA0003710110230000075
from the above formula, it can be seen that the sign of the dynamic equation partial derivative is related to the flow direction of the photovoltaic reactive power, and usually the new energy source unit operates under the control of the unit power factor, that is, the reactive power output is zero, and at this time, only the dynamic equation partial derivative term is present
Figure BDA0003710110230000076
Is not zero.
It is noted that the reactive power output of the photovoltaic and other new energy generating sets controlled by the GFL is completely controlled by x q Control, therefore, of
Figure BDA0003710110230000077
Characteristic of the symbol and
Figure BDA0003710110230000078
same, mixing h pv ＝P pv +jQ pv Substituting the interface equation can solve:
Figure BDA0003710110230000079
this means that
Figure BDA00037101102300000710
Is approximated as a fully positive matrix, and then
Figure BDA00037101102300000711
Also a fully positive matrix. The sign characteristics of a system voltage subsystem after the GFL is connected are obtained by utilizing a chain type derivation rule, when the GFL operates under the control of a unit power factor, the GFL is a monotonous system and still forms a monotonous system with the potential in a synchronous machine, the feedback between the GFL and an excitation system of the synchronous machine has a similar rule, namely the excitation system is in positive feedback to the GFL, and the GFL is in negative feedback to the excitation system, so that the voltage stability of the system after the GFL is connected can be analyzed by using a monotonous system theory.
2.7 Computing the Jacobian matrix symbolic feature of a network type current transformer (GFM): the mathematical model of GFM is:
Figure BDA00037101102300000712
Figure BDA00037101102300000713
in the formula: k is i And T u Is a time constant, E vir At an internal potential, E vir_fd For virtual excitation voltage, Q ref For a reactive power reference value, Q is the GFM output reactive power, V ref For terminal voltage reference, | V t I is GFM terminal voltage amplitude, K q And K u Respectively, the power coefficient and the voltage coefficient in the droop coefficient. The partial derivatives of the GFM dynamic equation are as follows:
Figure BDA0003710110230000081
Figure BDA0003710110230000082
Figure BDA0003710110230000083
Figure BDA0003710110230000084
Figure BDA0003710110230000085
the formula shows that the GFM has the same characteristic as the partial derivative sign of the dynamic equation of the synchronous machine and is combined
Figure BDA0003710110230000086
The sign characteristics can be known that the Jacobian matrix sign characteristics of the GFM are completely consistent with those of the synchronous machine.
2.8 Through comparing Jacobian matrix symbolic characteristics of a voltage subsystem of the power system, the fact that no matter what form the new energy unit is merged into the power grid is found, the new energy unit and the synchronous unit can form a form of an interconnected monotonous system, and then voltage stability analysis based on the interconnected monotonous system small gain theorem is carried out.
S3, based on the monotone system theory and the small gain stability criterion of the interconnected monotone system, the gain function Jacobian matrix spectrum radius is used as a quantitative evaluation index of the voltage stability of the power system to evaluate the voltage stability of the power system, and system parameters are adjusted according to the quantitative evaluation index to further improve the voltage stability of the system, and the method specifically comprises the following steps:
3.1 The small gain stability criterion of the interconnected monotonous system is as follows:
two interconnected input-output monotonic systems for the following equation:
Figure BDA0003710110230000087
Figure BDA0003710110230000088
v 1 ＝y 2
v 2 ＝-y 1
where x represents a state variable, y represents an output variable, and v represents an input variable, when the discrete iteration corresponding to the above equation:
Figure BDA0003710110230000089
converge to
Figure BDA00037101102300000810
Then the interconnected system is globally asymptotically stable, and
Figure BDA0003710110230000091
in the formula: k is a radical of y (. -) shows the static input-output behavior, i.e. for a fixed input v, there is a unique output k of the input-output system y (v)。
3.2 Feedback connection which can be divided into two monotonic systems according to the definition of interconnected input and output monotonic systems, namely an internal potential system (synchronous machine internal potential, GFL internal state variable and GFM internal voltage) and an excitation voltage system (synchronous machine excitation system and GFM virtual excitation), and a Jacobian matrix is divided into 4 parts
Figure BDA0003710110230000092
The feedback connection described above can be written as follows:
Figure BDA0003710110230000093
Figure BDA0003710110230000094
v E ＝y Efd
v Efd ＝-y E
in the formula: f. of Eq ,f Efd ,h Eq And h Efd Representing the corresponding non-linear equation. The steady state input-output characteristics of the system are:
Figure BDA0003710110230000095
Figure BDA0003710110230000096
in the formula: f. of -1 The inverse function is represented. Further discrete iterations can be written as:
Figure BDA0003710110230000097
in the formula: t (v) is a gain function whose Jacobian matrix has a spectral radius
Figure BDA0003710110230000098
And if the absolute value is less than 1, discrete iteration convergence is performed, and the Jacobian matrix spectrum radius of the gain function can be used as a quantitative evaluation index of the voltage stability of the power system to evaluate the voltage stability of the power system.
Solving the Jacobian matrix spectral radius of the gain function T (v)
Figure BDA0003710110230000099
When the absolute value of the spectrum radius is less than 1, discrete iteration converges, and the power system is indicated to be stable in voltage; when the absolute value of the spectrum radius is larger than or equal to 1, discrete iteration is not converged, and the risk of voltage instability of the power system is indicated.
3.3 Further analysis of the spectral radius of the gain function Jacobian matrix
Figure BDA00037101102300000910
And further, by a method for adjusting system parameters, the voltage stability of the system is improved: the Jacobian matrix is expressed as follows:
Figure BDA00037101102300000911
the following correspondence is noted:
Figure BDA00037101102300000912
the Jacobian matrix of the gain function may be represented by the Jacobian matrix of the voltage subsystem, where
Figure BDA00037101102300000913
And
Figure BDA00037101102300000914
it is clear that a non-negative matrix,
Figure BDA00037101102300000915
and
Figure BDA00037101102300000916
the inverse of (c) is also a non-negative matrix, so the radius of the Jacobian matrix spectrum can be analyzed based on the non-negative matrix theory.
For non-negative matrix A = [ a = ij ]0, A ≦ B is considered when 0 ≦ A-B, and the non-negative matrix has the following properties:
1) A, B, C and D are non-negative matrixes, when A is more than or equal to 0 and less than or equal to B and C is more than or equal to 0 and less than or equal to D, AC is more than or equal to 0 and less than or equal to BD.
2) Let A and B be non-negative matrixes, if A is less than or equal to B, then rho (A) is less than or equal to rho (B), wherein rho (·) is the spectrum radius of the matrixes.
It can be deduced from the non-negative matrix properties that the absolute value of the Jacobian matrix elements increases such that
Figure BDA0003710110230000101
Increase in absolute value of the element, ultimately leading to
Figure BDA0003710110230000102
If the absolute value is greater than 1, convergence of the discrete iteration system cannot be guaranteed, and accordingly system stability is poor. By observing the corresponding relation, the influence of the system parameters on the spectrum radius of the gain function Jacobian matrix can be obtained, and the system parameters are adjusted according to the quantitative evaluation indexes, so that the voltage stability of the system is improved.
The impact of system parameters on stability can be analyzed from analytical expressions of the Jacobian matrix:
1) From step 2.3) it can be seen that the transient reactance x' d Reduction of (2) and excitation amplification factor K A Will increase
Figure BDA0003710110230000105
Thus deteriorating the stability of the voltage subsystem;
2) As can be seen from the voltage subsystem symbolic diagram accessed into the GFL system, after the GFL replaces the synchronous machine, the system order is reduced, and the influence of the remaining synchronous machines on the stability of the system is increased, resulting in the deterioration of the system robustness;
3) The parameter K in the virtual synchronous control mode can be seen from the GFM mathematical model q The larger the size of the tube is,
Figure BDA0003710110230000103
the larger the diagonal element of (a), and therefore the smaller its inverse matrix element, the smaller the spectral radius; parameter K u The larger the size of the tube is,
Figure BDA0003710110230000104
the larger the element, the larger the spectral radius. Therefore, in a reasonable range, the Q-V droop coefficient K is theoretically q /K u The larger the voltage stability of the power system.
The invention has the beneficial effects that:
the photovoltaic grid-connected power system voltage stability analysis based on the monotonic system theory breaks through the limitation that a time domain simulation method is difficult to explain an internal stability mechanism, further explores the working principle and the stability mechanism of the new energy generator set participating in power grid voltage regulation, provides a voltage stability analysis method based on the interconnected monotonic system small gain theorem based on the monotonic dynamic system theory, and can judge the gradual stability of a voltage subsystem at a balance point according to the radius of a gain matrix spectrum led out by a system Jacobian matrix. Furthermore, according to a system Jacobian matrix analytical expression, the influence of system parameters on voltage stability is quantized, and a control design principle is provided for a novel power system with high penetration of new energy.
Drawings
FIG. 1 is a schematic flow diagram of the present invention;
FIG. 2 is a schematic diagram of a modular derivation process;
FIG. 3 is a voltage subsystem signature diagram for a pure synchronous machine system;
fig. 4 is a symbolic representation of a voltage subsystem that is switched into a GFL system;
fig. 5 is a symbolic representation of a voltage subsystem that is switched into a GFM system;
FIG. 6 is a graph of the effect of synchronizer parameters on spectral radius;
FIG. 7 shows the GFM sag factor influence on the spectral radius.
Detailed Description
The invention will be described more fully with reference to the accompanying drawings and examples.
The embodiment of the invention discloses a voltage stability analysis method of a photovoltaic grid-connected power system based on a monotone system theory, which comprises the following steps as shown in figure 1:
s1: dividing a dynamic equation of the power system into an element dynamic equation, a network equation and an interface equation, and providing a modular-based power system symbolic feature solving method;
s2: based on the modular derivation method in the S1, the Jacobian matrix symbolic characteristic of the voltage subsystem of the power system is obtained;
s3: based on a monotone system theory, the Jacobian matrix spectrum radius of a gain function is used as a criterion of the gradual stability of a system balance point, and the influence of partial power grid parameters on the Jacobian matrix spectrum radius of the gain function is quantized.
In the embodiment, the correctness and validity of the conclusion are verified in the 10-machine 39-node system calculation example. The generator combination is divided into three types:
case1: all the generator sets are synchronous generators, and the parameters of the synchronous generators are shown in the table 1;
case2: replacing the No. 1-4 synchronous machine with a photovoltaic generator set with a GFL (gas flow rate) as an interface, wherein GFL parameters are shown in a table 2;
case3: the 1-4 synchronous machines are replaced by photovoltaic generator sets with GFM as interfaces, and GFM parameters are shown in table 3.
TABLE 1 synchronizer part parameters
Figure BDA0003710110230000111
TABLE 2 GFL photovoltaic parameters
Figure BDA0003710110230000121
TABLE 3 GFM photovoltaic parameters
Figure BDA0003710110230000122
The step S1: the method is characterized in that a power system dynamic equation is divided into an element dynamic equation, a network equation and an interface equation, and a modular-based power system symbolic feature solving method is provided, wherein the steps are shown in fig. 2.
The step S2: based on the modular derivation method in S1, the Jacobian matrix symbolic characteristic of the voltage subsystem of the power system is obtained:
the Jacobian matrix symbolic property of a pure synchronous machine system is obtained in Case 1. In order to ensure that the voltage subsystem keeps the property of an interconnected monotonic system in the dynamic process of the system, a three-phase short-circuit fault is set at the moment t =0, the fault is cleared after 0.06s, and the change of the Jacobian matrix sign in the whole dynamic process is shown in FIG. 3;
and solving the Jacobian matrix symbolic characteristics of the GFL access system in Case 2. In Case2, a low-penetration process of the photovoltaic generator set is not considered, a three-phase short-circuit fault is set at the time t =0, the fault is cleared after 0.06s, only the autonomous recovery process of the system after the short-circuit is cleared is calculated, and the change of the Jacobian matrix symbols in the whole dynamic process is shown in fig. 4;
and solving the Jacobian matrix symbolic characteristics of the GFM access system in Case 3. In Case3, a three-phase short-circuit fault is set at the time of t =0, the fault is cleared after 0.06s, and the symbol changes of the Jacobian matrix in the whole dynamic process all conform to the symbol diagram shown in FIG. 5.
The step S3: based on a monotonous system theory, the Jacobian matrix spectrum radius of a gain function is used as a criterion of the gradual stability of a system balance point, and the influence of partial power grid parameters on the Jacobian matrix spectrum radius of the gain function is quantified:
in order to study the influence of parameters on the voltage stability of the system, the excitation amplification factor and the transient reactance of the No. 5 synchronous machine are gradually increased, a trend graph of the spectrum radius changing along with the parameters is calculated, and as a result, as shown in FIG. 6, it can be seen from FIG. 6 that the spectrum radius is continuously increased along with the reduction of the transient reactance of the synchronous machine and the increase of the amplification factor of the excitation system, which means that the gradual stability of the balance point of the voltage subsystem is damaged, and the voltage instability problem of the power system is more likely to occur.
In order to analyze the influence of the GFM voltage control mode on the system voltage stability, the Q-V droop coefficient K of the GFM is gradually increased q /K u The trend graph of the change of the spectrum radius with the droop coefficient is calculated, the result is shown in FIG. 7, and the droop coefficient K with the Q-V is shown in FIG. 7 q /K u The spectral radius gradually decreases. However, the speed of the decrease of the spectrum radius in the latter half section of the curve begins to be gentle, which shows that the overlarge droop coefficient not only can increase the power output pressure of the GFM when the voltage of the power grid drops, but also can affect the stability of the GFM and obviously improve the voltage stability. Therefore, the selection of the proper Q-V droop coefficient is beneficial to coordinating the stability requirements of the GFM and the whole power grid.
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. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (6)

1. A voltage stability analysis method of a photovoltaic grid-connected power system based on a monotone system theory is characterized by comprising the following steps:
s1: dividing a dynamic equation of the power system into an element dynamic equation, a network equation and an interface equation of an element and a network, and constructing a Jacobian matrix symbolic feature solving method based on the modularized power system;
s2: based on the symbol characteristic solving method in the step S1, solving the Jacobian matrix symbol characteristic of the voltage subsystem of the power system;
s3: based on a monotone system theory and a small gain stability criterion of an interconnected monotone system, the voltage stability of the power system is evaluated by taking the radius of a gain function Jacobian matrix spectrum as a quantitative evaluation index of the voltage stability of the power system, and system parameters are adjusted according to the index, so that the voltage stability of the system is improved.
2. The method for analyzing the voltage stability of the photovoltaic grid-connected power system based on the monotonic system theory according to claim 1, wherein the step S1 specifically comprises the following steps:
step 1.1: the power system dynamic equation is divided into three module parts:
a) Dynamic equation of the element:
Figure FDA00037101102200000110
b) Network equation:
Figure FDA0003710110220000019
c) Interface equation of element and network: s = h (x, V) x ,V y )；
Where x is the state variable of the element, V is the node voltage, V x And V y Respectively, xy components of port voltage of the element under a common coordinate system, S is power injected into a power system by the element, Y is a network admittance matrix, and an upper line represents the conjugate of a vector; h represents an interface equation of the element and the network;
step 1.2: obtaining partial derivatives of the three modules in the step 1.1, and then obtaining a Jacobian matrix of the whole system by utilizing a chain type derivation rule
Figure FDA0003710110220000018
The method comprises the following specific steps:
Figure FDA0003710110220000011
in the formula:
Figure FDA0003710110220000012
and
Figure FDA0003710110220000013
directly solving by an element dynamic equation;
Figure FDA0003710110220000014
and
Figure FDA0003710110220000017
and solving through a simultaneous network equation and an interface equation.
3. The method for analyzing the voltage stability of the photovoltaic grid-connected power system based on the monotonic system theory as claimed in claim 2, wherein in the step 1.2:
Figure FDA0003710110220000015
and
Figure FDA0003710110220000016
the method is obtained through a simultaneous network equation and an interface equation, and comprises the following specific steps:
combining the network equation and the interface equation to obtain:
Figure FDA0003710110220000021
the two sides of equation (2) are subjected to the partial derivation of x by means of the chain rule:
Figure FDA0003710110220000022
substituting the second formula in formula (3) into the first formula to eliminate
Figure FDA00037101102200000210
Obtaining:
Figure FDA0003710110220000023
will be provided with
Figure FDA0003710110220000024
After the formula (4) is substituted, the following partial derivatives of the interface equation are obtained:
Figure FDA0003710110220000025
for equation (6), let:
Figure FDA0003710110220000026
substituting the formula (7) into the formula (6) and then taking conjugation to obtain an equation set:
Figure FDA0003710110220000027
solving to obtain:
Figure FDA0003710110220000028
and:
Figure FDA0003710110220000029
substituting equation (10) for equation (1) yields the Jacobian matrix of the whole system.
4. The method for analyzing the voltage stability of the photovoltaic grid-connected power system based on the monotonic system theory according to claim 1, wherein the step S2 specifically comprises:
step 2.1) obtaining a Jacobian matrix of the transient potential of the synchronous machine:
step 2.1.1) combining the dynamic equation of the synchronous machine voltage subsystem with the stator voltage equation and the coordinate transformation formula to obtain the synchronous machine dynamic equation only containing voltage variables and state variables:
Figure FDA0003710110220000031
Figure FDA0003710110220000032
the dynamic equation of the synchronous machine voltage subsystem comprises a transient potential dynamic equation and an excitation voltage dynamic equation of the synchronous machine voltage subsystem, and the transient potential dynamic equation and the excitation voltage dynamic equation are respectively as follows:
Figure FDA0003710110220000033
the stator voltage equation is:
Figure FDA0003710110220000034
the coordinate transformation formula is as follows:
Figure FDA0003710110220000035
in the formula: t' d0 Is an open circuit time constant, E' q Transient potential after transient reactance, E fd Is an excitation voltage, x d 、x q And x' d Synchronous reactance, q-axis reactance and transient reactance, V, respectively x And V y Respectively xy component, V, of the terminal voltage of the synchronous machine on a common coordinate axis d And V q Dq components, I, of the terminal voltage of the synchronous machine in its own dq coordinate system d And I q Respectively dq components of the output current of the synchronous machine in a dq coordinate system of the synchronous machine, delta is a rotor angle, T A As excitation time constant, K A For the excitation amplification factor, V ref For exciting the reference voltage, V t Is the terminal voltage of the synchronous machine;
further, the partial derivatives of the transient potential dynamic equation of the synchronous machine dynamic equation are obtained as follows:
Figure FDA0003710110220000036
step 2.1.2) interface equation h of the synchronous machine according to the following formula SM ：
Figure FDA0003710110220000037
Solving the related partial derivatives of the interface equation of the synchronous machine as follows:
Figure FDA0003710110220000041
step 2.1.3) incorporating the load as a constant impedance into the network equation of step 1
Figure FDA0003710110220000042
And utilizing Kron transformation to eliminate the intermediate node to obtain a network equation after the intermediate node is eliminated, substituting the first formula of formula (17) into the A matrix expression in step 1, namely formula (7), to obtain:
Figure FDA0003710110220000043
in the formula: diag (. Circle.) denotes a diagonal matrix composed of bracketed elements, n is the number of synchronizer nodes, Y aug Re-merging the admittance matrix Y after Kron transformation into synchronous machine reactance
Figure FDA0003710110220000044
Substituting the second formula and the third formula of the formula (17) into the B matrix expression and the C matrix expression in the step 1, namely the formula (7), and calculating to obtain the B matrix expression and the C matrix expression as follows:
Figure FDA0003710110220000045
step 2.1.4) solving the partial derivative of the voltage to the transient potential according to the formula (9) of the step 1
Figure FDA0003710110220000049
Figure FDA0003710110220000046
Substituting the expressions of A and C in step 2.1.3) into formula (20) to obtain:
Figure FDA0003710110220000047
step 2.1.5) adjusting the reference phase to enable the angle of the q axis of the synchronous machine relative to the reference machine to be within +/-30 degrees, substituting the equation (15) and the equation (21) into the full-system Jacobian matrix of the equation (1) to obtain a Jacobian matrix of the transient potential of the synchronous machine:
Figure FDA0003710110220000048
in formula (II) T' d0i Showing the open-circuit time constant of the ith synchronous machine;
off-diagonal elements of the Jacobian matrix of the transient potentials of the synchronous machine are all positive numbers, the monotonic system condition is satisfied;
step 2.2) solving a Jacobian matrix of the excitation voltage of the synchronous machine to the transient potential:
solving a partial derivative term of an excitation system dynamic equation according to a synchronous machine dynamic equation:
Figure FDA0003710110220000051
obtaining a Jacobian matrix of the excitation voltage of the synchronous machine to the transient potential according to the step 2.2) as follows:
Figure FDA0003710110220000052
it is known that
Figure FDA0003710110220000055
Is a non-negative matrix, and the real part is far greater than the imaginary part, V x If the transient potential is positive, the Jacobian matrix of the excitation voltage relative to the transient potential is deduced to be a negative matrix, so that the transient potential is determined to be the negative feedback signal input of the excitation system;
step 2.3) obtaining a Jacobian matrix of the excitation system:
jacobian matrix of excitation voltage to excitation voltage
Figure FDA0003710110220000056
Only with
Figure FDA0003710110220000059
Terms relate to, i.e.:
Figure FDA0003710110220000057
in the formula: t is A Is composed of T Ai Forming a diagonal matrix;
step 2.4) solving a Jacobian matrix from the excitation system to the transient potential:
the Jacobian matrix of transient potential to excitation voltage is only AND
Figure FDA0003710110220000058
The terms relate to, namely:
Figure FDA0003710110220000053
in the formula: t is d0 Is composed of T d0i Forming a diagonal matrix;
step 2.5) obtaining the Jacobian matrix symbol characteristic of the net-type converter GFL:
the influence of active power is not considered, and a dynamic equation and an interface equation of GFL of only a reactive power control link are obtained:
Figure FDA0003710110220000054
in the formula, x q Representing internal state variables, Q, corresponding to reactive power ref Reference value, P, representing output power pv And Q pv Representing the output active and reactive power of the GFL, K p Which represents the amplification factor of the PI control,
Figure FDA00037101102200000510
terminal voltage amplitude of GFL;
acquiring a partial derivative term of a GFL dynamic equation, which specifically comprises the following steps:
Figure FDA0003710110220000061
solving a network equation and a GFL interface equation h according to the step 2.1.3) and the step 2.1.4) pv Associated partial derivatives of
Figure FDA0003710110220000064
Then, using the chain-derived rule, the equations (28) and (iv) are combined
Figure FDA0003710110220000065
Substituting the whole system Jacobian matrix of the formula (1) to obtain a Jacobian matrix of the power system added with the GFL;
the Jacobian matrix of the power system after the GFL is added accords with the symbolic feature of the monotonic system;
step 2.6) obtaining Jacobian matrix symbol characteristics of the GFM:
the GFM dynamic equation and the interface equation are:
Figure FDA0003710110220000062
in the formula: k is i And T u Is a time constant, E vir At an internal potential, E vir_fd For virtual excitation voltage, Q ref For a reactive power reference value, Q is the GFM output reactive power, V ref For terminal voltage reference, | V t I is GFM terminal voltage amplitude, K q And K u Respectively power coefficient and voltage coefficient, h, of the droop coefficient vsg As an interface equation, V x And V y Xy components of GFM end voltage on a common coordinate axis respectively, delta is a virtual rotor angle, and x l Is a line reactance;
the partial derivatives of the GFM dynamic equation are as follows:
Figure FDA0003710110220000063
solving a network equation and a GFM interface equation h according to the step 2.1.3) and the step 2.1.4) vsg Associated partial derivatives of
Figure FDA0003710110220000066
And
Figure FDA0003710110220000067
then, using the chain-derived rule, the equations (30) and (iv) are combined
Figure FDA0003710110220000068
And
Figure FDA0003710110220000069
substituting the full-system Jacobian matrix of the formula (1) to obtain the Jacobian matrix of the power system added with the GFM:
the Jacobian matrix symbol characteristic of the GFM is completely consistent with that of the synchronous machine in the steps 2.1) to 2.4).
5. The method for analyzing the voltage stability of the photovoltaic grid-connected power system based on the monotonic system theory according to claim 1, wherein the step S3 specifically comprises:
3.1 The small gain criterion of the interconnected monotonic system is as follows:
two interconnected input-output monotonic systems for the following equation:
Figure FDA0003710110220000071
wherein x represents a state variable, y represents an output variable, v represents an input variable, subscript 1 represents a variable of a first system, and subscript 2 represents a variable of a second system;
when the discrete iteration corresponding to equation (31) converges to
Figure FDA00037101102200000710
And then, the interconnected system is represented to be globally and gradually stable, and the corresponding discrete iteration is represented as follows:
Figure FDA0003710110220000072
in the formula (32), k y (-) represents a static input-output characteristic;
3.2 According to the interconnected input-output monotonic system definition, the Jacobian matrix of the power system is divided into two feedback connections of monotonic system, namely an internal potential system and an excitation voltage system, and the Jacobian matrix of the power system is divided into
Figure FDA0003710110220000075
And
Figure FDA0003710110220000076
four parts;
the form of the feedback connection for the two monotonic systems is as follows:
Figure FDA0003710110220000073
in the formula (f) E ,f Efd ,h E And h Efd Respectively representing corresponding nonlinear equations;
the discrete iteration corresponding to equation (33) is:
Figure FDA0003710110220000078
the static input-output characteristics of two monotonic systems are:
Figure FDA0003710110220000077
Figure FDA0003710110220000074
in the formula: f. of -1 Representing an inverse function, T (v) being a gain function;
solving the Jacobian matrix spectral radius of the gain function T (v)
Figure FDA0003710110220000079
When the absolute value of the spectrum radius is less than 1, discrete iteration converges, and the power system is indicated to be stable in voltage; when the absolute value of the spectrum radius is greater than or equal to 1, discrete iteration is not converged, and the risk of voltage instability of the power system is indicated;
3.3 By adjusting system parameters, improve system voltage stabilization:
the Jacobian matrix of the gain function T (v) is expressed as follows:
Figure FDA0003710110220000081
expressing the Jacobian matrix of the gain function by the Jacobian matrix of the voltage subsystem, namely, after the nonlinear equation in the formula (36) is respectively corresponding to the dynamic equation of the synchronous machine in the formula (11), the dynamic equation of the GFL in the formula (27) and the dynamic equation of the GFM in the formula (29), obtaining the following corresponding relation:
Figure FDA0003710110220000082
when in use
Figure FDA0003710110220000084
When the absolute value is larger than 1, K in the formula (11) is reduced A Or K in formula (29) u And K in the formula (29) is increased q So that
Figure FDA0003710110220000083
And the voltage stability of the system is improved.
6. The method for analyzing the voltage stability of the photovoltaic grid-connected power system based on the monotonic system theory as claimed in claim 5, wherein in the step 3.2): the internal potential system comprises a synchronous internal potential, a GFL internal state variable and a GFM internal voltage; the excitation voltage system comprises a synchronous machine excitation system and a GFM virtual excitation system.
CN202210723585.4A 2022-06-23 2022-06-23 Voltage stability analysis method for photovoltaic grid-connected power system based on monotonic system theory Pending CN115149582A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210723585.4A CN115149582A (en) 2022-06-23 2022-06-23 Voltage stability analysis method for photovoltaic grid-connected power system based on monotonic system theory

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210723585.4A CN115149582A (en) 2022-06-23 2022-06-23 Voltage stability analysis method for photovoltaic grid-connected power system based on monotonic system theory

Publications (1)

Publication Number Publication Date
CN115149582A true CN115149582A (en) 2022-10-04

Family

ID=83407441

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210723585.4A Pending CN115149582A (en) 2022-06-23 2022-06-23 Voltage stability analysis method for photovoltaic grid-connected power system based on monotonic system theory

Country Status (1)

Country Link
CN (1) CN115149582A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116937624A (en) * 2023-09-18 2023-10-24 国网江西省电力有限公司电力科学研究院 Design method and system of oscillation suppressor with network construction photovoltaic damping and voltage coordination

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116937624A (en) * 2023-09-18 2023-10-24 国网江西省电力有限公司电力科学研究院 Design method and system of oscillation suppressor with network construction photovoltaic damping and voltage coordination
CN116937624B (en) * 2023-09-18 2023-12-26 国网江西省电力有限公司电力科学研究院 Design method and system of oscillation suppressor with network construction photovoltaic damping and voltage coordination

Similar Documents

Publication Publication Date Title
CN111541274A (en) Island microgrid control strategy based on virtual synchronous generator characteristics
CN108767869B (en) Static reactive power compensator voltage adjusting method based on artificial neural network
CN108964040B (en) Power-current coordination control method for virtual synchronous generator under power grid imbalance
CN112003322A (en) Method for designing control parameters of grid-connected converter of micro-grid system
CN110556871B (en) Aggregation equivalence method for large-scale photovoltaic power generation system based on structure keeping method
said Adouairi et al. Application of fuzzy sliding mode control on a single-stage grid-connected PV system based on the voltage-oriented control strategy
Satpathy et al. Control of a STATCOM‐assisted self‐excited induction generator‐based WECS feeding non‐linear three‐phase and single‐phase loads
Debdouche et al. Robust integral backstepping control microgrid connected photovoltaic System with battery energy storage through multi-functional voltage source inverter using direct power control SVM strategies
CN106602610B (en) A kind of method for building up of wind power plant Equivalent Model
CN115149582A (en) Voltage stability analysis method for photovoltaic grid-connected power system based on monotonic system theory
CN110266044B (en) Microgrid grid-connected control system and method based on energy storage converter
Pedra et al. Comparison of small-signal admittance-based models of doubly-fed induction generators
CN113991715A (en) Control method of medium-voltage direct-hanging asymmetric hybrid energy storage system under non-ideal power grid
CN111555358A (en) Multi-distributed power supply parallel operation method based on self-adaptive droop control
Benazza et al. Backstepping control of three-phase multilevel series active power filter
CN111900738B (en) Three-phase unbalanced load flow calculation method based on compensation algorithm
CN111525567B (en) Method and device for calculating fault current of photovoltaic grid-connected inverter
Ram et al. Enhancement of power quality using U-SOGI based control algorithm for DSTATCOM
Ashajyothi et al. Power Quality Improvement in 3-Phase Power System Using Artificial Neural Network Based Hybrid Filter
Marcu et al. Comparative analysis of methods for reducing distorting regime by simulating active power filters
Lakshmi et al. Investigation of distribution static compensator formitigation of nonlinear loads
Ghosh et al. Design and Implementation of Super Twisting Sliding Mode Control for PV Grid-connected Water Pumping System
CN117424294B (en) Efficient reactive power planning method and system for power distribution network
Bhavya et al. Performance evaluation of weighted feedback based upqc under various power quality issues
CN112018787B (en) Three-phase unbalanced time sequence simulation method of distributed power supply

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination