CN109975662A - A kind of phase-selecting method and device of photovoltaic plant access power grid - Google Patents
A kind of phase-selecting method and device of photovoltaic plant access power grid Download PDFInfo
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- CN109975662A CN109975662A CN201910339165.4A CN201910339165A CN109975662A CN 109975662 A CN109975662 A CN 109975662A CN 201910339165 A CN201910339165 A CN 201910339165A CN 109975662 A CN109975662 A CN 109975662A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/088—Aspects of digital computing
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S10/00—Systems supporting electrical power generation, transmission or distribution
- Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
- Y04S10/52—Outage or fault management, e.g. fault detection or location
Abstract
The invention discloses phase-selecting method, device, equipment and the computer readable storage medium of a kind of photovoltaic plant access power grid, method includes: the voltage between phases before obtaining three-phase voltage and failure of the protection installation place of photovoltaic plant side before failure and when failure respectively and when failure；Positive sequence false voltage component, negative phase-sequence false voltage component and the zero-sequence fault component of voltage of phase voltage Sudden Changing Rate and A phase voltage are obtained using three-phase voltage, and obtains voltage between phases Sudden Changing Rate using voltage between phases；Judge whether positive sequence voltage Drop coefficient is more than or equal to preset threshold；If so, determining fault type by phase relation and negative phase-sequence false voltage component, zero-sequence fault component of voltage；If it is not, then determining fault type by phase voltage magnitude relation, voltage between phases magnitude relation and zero-sequence fault component of voltage.Above-mentioned technical proposal disclosed in the present application protects the voltage condition of installation place that the alternating current circuit fault type being connected with photovoltaic plant can be recognized accurately by photovoltaic plant side.
Description
Technical field
The present invention relates to Relay Protection Technology in Power System fields, access electricity more specifically to a kind of photovoltaic plant
Phase-selecting method, device, equipment and the computer readable storage medium of net.
Background technique
With the continuous promotion of photovoltaic power generation technology, the installed capacity of photovoltaic plant is growing, the infiltration in power grid
Saturating rate is also being continuously improved.Different from the conventional synchronization power grid based on synchronous generator, the fault current of photovoltaic plant output with
Value and power reference, fault type, control target and the factors such as the conveyance capacity of power electronic devices are related.
Currently, the phase selection element in existing power grid is designed based on traditional alternating current circuit fault signature, it is
The core element of distance protection and automatic reclosing, therefore, in order to ensure power grid can safe and stable operation, then need phase selection first
Part can correctly identify failure phase.But the AC line being connected with photovoltaic plant can be changed after accessing power grid due to photovoltaic plant
The access of the fault current feature on road, i.e. photovoltaic plant will lead to the event of fault current feature Yu conventional synchronization power grid alternating current circuit
It is larger to hinder current characteristic diversity ratio, therefore, then will lead to the phase current being designed to based on conventional AC line fault current characteristic
There are adaptability problems for poor Sudden Changing Rate phase selection element and current sequence components phase selection element, that is, will lead to the phase selection member in existing power grid
Part cannot correctly identify the alternating current circuit fault type being connected with photovoltaic plant, and phase selection element cannot correctly identify failure classes
Type may result in the incorrect operation of distance protection and automatic reclosing, may finally make to the safe and stable operation of power grid
At threat.
In conclusion the alternating current circuit fault type being connected with photovoltaic plant how is recognized accurately, to ensure that power grid can
It is current those skilled in the art technical problem urgently to be resolved with safe and stable operation.
Summary of the invention
In view of this, the object of the present invention is to provide a kind of photovoltaic plant access phase-selecting method of power grid, device, equipment and
Computer readable storage medium, the alternating current circuit fault type being connected with photovoltaic plant is recognized accurately, so that it is guaranteed that power grid
It can be with safe and stable operation.
To achieve the goals above, the invention provides the following technical scheme:
A kind of phase-selecting method of photovoltaic plant access power grid, comprising:
It is respectively before three-phase voltage and failure of the protection installation place of acquisition photovoltaic plant side before failure and when failure and former
Voltage between phases when barrier；
Phase voltage Sudden Changing Rate and the positive sequence false voltage component of A phase voltage, negative phase-sequence failure are obtained using the three-phase voltage
Component of voltage and zero-sequence fault component of voltage, and voltage between phases Sudden Changing Rate is obtained using the voltage between phases；
Positive sequence voltage Drop coefficient is obtained according to the positive sequence voltage amplitude of A phase, the rated voltage amplitude of A phase before failure, is sentenced
Whether the positive sequence voltage Drop coefficient that breaks is more than or equal to preset threshold；
If so, passing through the positive sequence false voltage component of the A phase voltage, the negative phase-sequence false voltage component and described zero
Sequence false voltage component obtains phase relation, and passes through the phase relation and the negative phase-sequence false voltage component, the zero sequence
False voltage component determines fault type；
If it is not, then obtaining phase voltage magnitude relation by the phase voltage Sudden Changing Rate, pass through the voltage between phases Sudden Changing Rate
Voltage between phases magnitude relation is obtained, and passes through the phase voltage magnitude relation, the voltage between phases magnitude relation and the zero sequence
False voltage component determines fault type.
Preferably, the positive sequence false voltage component of phase voltage Sudden Changing Rate and A phase voltage is obtained using the three-phase voltage, bear
Sequence false voltage component and zero-sequence fault component of voltage, and voltage between phases Sudden Changing Rate is obtained using the voltage between phases, comprising:
Utilize A phase voltage when failureB phase voltageC phase voltageAnd A phase voltage before failureB phase electricity
PressureC phase voltageAccording toCalculate separately A phase phase voltage Sudden Changing RateB phase phase voltage is prominent
VariableC phase phase voltage Sudden Changing RateWherein, M is the protection installation place of photovoltaic plant side；
According toA phase voltage positive-sequence component when calculating separately failureFailure
Preceding A phase voltage positive-sequence componentA phase voltage negative sequence component when failureA phase voltage zero-sequence component when failureAnd
According toObtain the positive sequence false voltage component of A phase voltageAccording toObtain A phase electricity
The negative phase-sequence false voltage component of pressureAccording toObtain the zero-sequence fault component of voltage of A phase voltageWherein,
α=ej120°；
Utilize AB phase phase voltage when failureBC phase phase voltageCA phase phase voltageAnd AB phase phase before failure
VoltageBC phase phase voltageCA phase phase voltageAccording toCalculate separately AB Xiang Xiang electricity
Pressure mutation componentBC phase phase voltage is mutated componentCA phase phase voltage is mutated component
Preferably, pass through the positive sequence false voltage component of the A phase voltage, the negative phase-sequence false voltage component and described zero
Sequence false voltage component obtains phase relation, and passes through the phase relation and the negative phase-sequence false voltage component, the zero sequence
False voltage component determines fault type, comprising:
It utilizesCalculate separately γ and β, wherein arg () indicates to take the width of phasor
Angle；
JudgementWhether 0 is equal to, wherein | | it indicates to take the amplitude of voltage phasor；
IfEqual to 0, then judgeWhether 0 is equal to, ifEqual to 0, then it is determined as three phase short circuit fault, ifNot equal to 0, then the section of β is judged: if 0 ° of -120 °≤β <, is determined as AB phase fault；If 240 ° of 120 °≤β <,
Then it is determined as BC phase fault；If 120 ° of 0 °≤β <, is determined as CA phase fault；
IfNot equal to 0, then fault type is determined by γ and β: if γ ∈ (- 30 °, 30 °) and β ∈ (- 60 °,
60 °), then it is determined as A phase ground fault；If γ ∈ (90 °, 150 °) and β ∈ (- 180 °, -60 °), then it is determined as that B phase is grounded event
Barrier；If γ ∈ (- 150 °, -90 °) and β ∈ (60 °, 180 °), then be determined as C phase ground fault；If γ ∈ (- 150 °, -30 °) and
β ∈ (- 120 °, 0 °), then be determined as AB phase ground fault；If γ ∈ (- 30 °, 90 °) and β ∈ (120 °, 240 °), then be determined as
BC phase ground fault；If γ ∈ (90 °, 210 °) and β ∈ (0 °, 120 °), then be determined as CA phase ground fault.
Preferably, phase voltage magnitude relation is obtained by the phase voltage Sudden Changing Rate, passes through the voltage between phases Sudden Changing Rate
Voltage between phases Sudden Changing Rate magnitude relation is obtained, and passes through the phase voltage magnitude relation, the voltage between phases magnitude relation and institute
It states zero-sequence fault component of voltage and determines fault type, comprising:
It utilizesPoint
It Ji Suan not m1、m2、m3、n1、n2、n3；
JudgementWhether 0 is equal to, wherein indicate to take the amplitude of voltage phasor；
IfEqual to 0, then n is judged2And n3Whether (n is met2>z)&(1/n3> z), if so, being determined as that AB is alternate short
Road failure；Judge n3And n1Whether (n is met3>z)&(1/n1> z), if so, being determined as BC phase fault；Judge n1And n2Whether
Meet (n1>z)&(1/n2> z), if so, being determined as CA phase fault；If n1、n2、n3(n is not satisfied2>z)&(1/n3>z)、
(n3>z)&(1/n1>z)、(n1>z)&(1/n2> z), then it is determined as three phase short circuit fault, wherein z=4~8；
IfNot equal to 0, then m is judged1And m2Whether (m is met1>z)&(1/m2> z), if so, being determined as that A phase is grounded
Failure；Judge m2And m3Whether (m is met2>z)&(1/m3> z), if so, being determined as B phase ground fault；Judge m1And m3Whether
Meet (m3>z)&(1/m1> z), if so, being determined as C phase ground fault；
If m1、m2、m3(m is not satisfied1>z)&(1/m2>z)、(m2>z)&(1/m3>z)、(m3>z)&(1/m1> z), then determine
For double earthfault, wherein the two-phase in the double earthfault isMiddle amplitude compared with
Big two-phase.
Preferably, the preset threshold is any value in [0.8,0.9].
A kind of phase selection device of photovoltaic plant access power grid, comprising:
Obtain module, for obtain respectively the protection installation place of photovoltaic plant side before failure with three-phase voltage when failure
And the voltage between phases before failure and when failure；
Computing module, for obtaining the positive sequence false voltage of phase voltage Sudden Changing Rate and A phase voltage using the three-phase voltage
Component, negative phase-sequence false voltage component and zero-sequence fault component of voltage, and voltage between phases Sudden Changing Rate is obtained using the voltage between phases；
Judgment module, for obtaining positive sequence electricity according to the positive sequence voltage amplitude of A phase, the rated voltage amplitude of A phase before failure
Drop coefficient is pressed, judges whether the positive sequence voltage Drop coefficient is more than or equal to preset threshold；
First determining module, for when the judgment module is judged to being, then passing through the positive sequence failure of the A phase voltage
Component of voltage, the negative phase-sequence false voltage component and the zero-sequence fault component of voltage obtain phase relation, and pass through the phase
Position relationship and the negative phase-sequence false voltage component, the zero-sequence fault component of voltage determine fault type；
Second determining module, for when the judgment module is determined as no, then being obtained by the phase voltage Sudden Changing Rate
Phase voltage magnitude relation obtains voltage between phases magnitude relation by the voltage between phases Sudden Changing Rate, and passes through the phase voltage width
Value relationship, the voltage between phases magnitude relation and the zero-sequence fault component of voltage determine fault type.
Preferably, the computing module includes:
First computing unit, for utilizing A phase voltage when failureB phase voltageC phase voltageAnd A before failure
Phase voltageB phase voltageC phase voltageAccording toCalculate separately A phase phase voltage Sudden Changing RateB phase phase voltage Sudden Changing RateC phase phase voltage Sudden Changing RateWherein, M is that the protection of photovoltaic plant side is installed
Place；
Second computing unit is used for basisA phase voltage when calculating separately failure
Positive-sequence componentA phase voltage positive-sequence component before failureA phase voltage negative sequence component when failureA phase electricity when failure
Press zero-sequence componentAnd according toObtain the positive sequence false voltage component of A phase voltageAccording toObtain the negative phase-sequence false voltage component of A phase voltageAccording toObtain the zero-sequence fault of A phase voltage
Component of voltageWherein, α=ej120°；
Third computing unit, for utilizing AB phase phase voltage when failureBC phase phase voltageCA phase phase voltageAnd AB phase phase voltage before failureBC phase phase voltageCA phase phase voltageAccording toCalculate separately AB phase phase voltage mutation componentBC phase phase voltage is mutated componentCA
Phase phase voltage is mutated component
Preferably, first determining module includes:
4th computing unit, for utilizingCalculate separately γ and β, wherein arg
() indicates to take the argument of phasor；
First judging unit, for judgingWhether 0 is equal to, wherein | | it indicates to take the amplitude of voltage phasor；
First judging unit, if forEqual to 0, then judgeWhether 0 is equal to, ifEqual to 0, then determine
For three phase short circuit fault, ifNot equal to 0, then the section of β is judged: if 0 ° of -120 °≤β <, being determined as that AB is alternate short
Road；If 240 ° of 120 °≤β <, is determined as BC phase fault；If 120 ° of 0 °≤β <, is determined as CA phase fault；
Second judging unit, if forNot equal to 0, then fault type is determined by γ and β: if γ ∈ (- 30 °,
30 °) and β ∈ (- 60 °, 60 °), then it is determined as A phase ground fault；If γ ∈ (90 °, 150 °) and β ∈ (- 180 °, -60 °), then
It is determined as B phase ground fault；If γ ∈ (- 150 °, -90 °) and β ∈ (60 °, 180 °), then be determined as C phase ground fault；If γ
∈ (- 150 °, -30 °) and β ∈ (- 120 °, 0 °), then be determined as AB phase ground fault；If γ ∈ (- 30 °, 90 °) and β ∈
(120 °, 240 °), then be determined as BC phase ground fault；If γ ∈ (90 °, 210 °) and β ∈ (0 °, 120 °), then be determined as CA phase
Ground fault.
A kind of phase selection equipment of photovoltaic plant access power grid, comprising:
Memory, for storing computer program；
Processor realizes photovoltaic plant access power grid as described in any one of the above embodiments when for executing the computer program
Phase-selecting method the step of.
A kind of computer readable storage medium is stored with computer program on the computer readable storage medium, described
The step of the phase-selecting method of photovoltaic plant access power grid as described in any one of the above embodiments is realized when computer program is executed by processor
Suddenly.
The present invention provides phase-selecting method, device, equipment and the computer-readable storages of a kind of photovoltaic plant access power grid
Medium, wherein this method comprises: obtaining three-phase voltage of the protection installation place of photovoltaic plant side before failure and when failure respectively
And the voltage between phases before failure and when failure；The positive sequence failure electricity of phase voltage Sudden Changing Rate and A phase voltage is obtained using three-phase voltage
Component, negative phase-sequence false voltage component and zero-sequence fault component of voltage are pressed, and obtains voltage between phases Sudden Changing Rate using voltage between phases；Root
Positive sequence voltage Drop coefficient is obtained according to the positive sequence voltage amplitude of A phase, the rated voltage amplitude of A phase before failure, judges positive sequence voltage
Whether Drop coefficient is more than or equal to preset threshold；If so, passing through the positive sequence false voltage component of A phase voltage, negative phase-sequence failure electricity
Pressure component and zero-sequence fault component of voltage obtain phase relation, and pass through phase relation and negative phase-sequence false voltage component, zero sequence event
Barrier component of voltage determines fault type；If it is not, then obtaining phase voltage magnitude relation by phase voltage Sudden Changing Rate, pass through voltage between phases
Sudden Changing Rate obtains voltage between phases magnitude relation, and passes through phase voltage magnitude relation, voltage between phases magnitude relation and zero-sequence fault electricity
Pressure component determines fault type.
Above-mentioned technical proposal disclosed in the present application, obtain the protection installation place of photovoltaic plant side before failure with failure when
Three-phase voltage, and voltage between phases of the protection installation place before failure and when failure is obtained, it is obtained using three-phase voltage and voltage between phases
To positive sequence false voltage component, the negative phase-sequence false voltage component and zero of phase voltage Sudden Changing Rate, voltage between phases Sudden Changing Rate and A phase voltage
Sequence false voltage component, and the calculated positive sequence voltage Drop coefficient of institute is compared with preset threshold, when positive sequence voltage falls
When falling coefficient more than or equal to preset threshold, pass through positive sequence false voltage component, negative phase-sequence false voltage component and the zero sequence of A phase voltage
The phase relation and negative phase-sequence false voltage component of false voltage component, zero-sequence fault component of voltage determine fault type, work as positive sequence
When Voltage Drop coefficient is less than or equal to preset value, pass through phase voltage magnitude relation, voltage between phases magnitude relation and zero-sequence fault electricity
Component is pressed to determine fault type.Since influence of the photovoltaic plant when accessing power grid to voltage is smaller, pass through photovoltaic electric
Stand side protection installation place voltage condition accurately identifying for the alternating current circuit fault type being connected with photovoltaic plant then may be implemented,
So as to ensure the safe and stable operation of power grid.
Detailed description of the invention
In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, to embodiment or will show below
There is attached drawing needed in technical description to be briefly described, it should be apparent that, the accompanying drawings in the following description is only this
The embodiment of invention for those of ordinary skill in the art without creative efforts, can also basis
The attached drawing of offer obtains other attached drawings.
Fig. 1 is the flow chart for the phase-selecting method that a kind of photovoltaic plant provided in an embodiment of the present invention accesses power grid；
Fig. 2 is the structural schematic diagram that photovoltaic plant provided in an embodiment of the present invention accesses power grid；
Fig. 3 is judgement k provided in an embodiment of the present inventionλWith the relationship of preset threshold and the process of progress fault type judges
Figure；
Fig. 4 is the γ block plan of voltage sequence fault component phase selection element provided in an embodiment of the present invention；
Fig. 5 is the β block plan of voltage sequence fault component phase selection element provided in an embodiment of the present invention；
Fig. 6 is that the A phase that resistance is 1 Ω that breaks down at photovoltaic plant transmission line of electricity f provided in an embodiment of the present invention is grounded
Magnitude relation figure when failure；
Fig. 7 is that the A that resistance is 100 Ω that breaks down at photovoltaic plant transmission line of electricity f provided in an embodiment of the present invention connects
Each sequence fault component phase diagram when earth fault；
Fig. 8 is the structural schematic diagram for the phase selection device that a kind of photovoltaic plant provided in an embodiment of the present invention accesses power grid；
Fig. 9 is the structural schematic diagram for the phase selection equipment that a kind of photovoltaic plant provided in an embodiment of the present invention accesses power grid.
Specific embodiment
Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, complete
Site preparation description, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.It is based on
Embodiment in the present invention, it is obtained by those of ordinary skill in the art without making creative efforts every other
Embodiment shall fall within the protection scope of the present invention.
Referring to Fig. 1 and Fig. 2, wherein Fig. 1 shows a kind of choosing of photovoltaic plant access power grid provided in an embodiment of the present invention
The flow chart of phase method, Fig. 2 shows the structural schematic diagrams of photovoltaic plant provided in an embodiment of the present invention access power grid.The present invention
A kind of photovoltaic plant that embodiment provides accesses the phase-selecting method of power grid, may include:
S11: before obtaining three-phase voltage and failure of the protection installation place of photovoltaic plant side before failure and when failure respectively
With voltage between phases when failure.
In view of the voltage in power grid influenced by grid side it is bigger, and hardly by the shadow of the photovoltaic plant accessed
It rings, therefore, when alternating current circuit is broken down, in order to enable phase selection element that alternating current circuit fault type is recognized accurately, with
Act distance protection and automatic reclosing correctly, so that it is guaranteed that the safe and stable operation of power grid, then can pass through
Voltage condition identifies fault type.Furthermore, it is contemplated that the line fault occurred on the transmission line of electricity of photovoltaic plant is (such as in light
Line fault occurs at the transmission line of electricity midpoint f of overhead utility) (Fig. 2 can be referred specifically to the protection installation place for being located at photovoltaic plant side
In M at) have an impact, and hardly to be located at the synchronised grids side (E in Fig. 2SRepresent synchronous generator) protection peace
It (refers specifically at the N in Fig. 2) have an impact at dress, therefore, then phase selection only can be carried out using the scheme of the application at M, and
For at N then phase selection can be carried out using existing scheme.
It should be noted that the detection device for playing detection can be with real-time detection in the power grid for being connected to photovoltaic plant
The information of voltage of the protection installation place (at specific N) of the protection installation place (at M) and synchronised grids side of photovoltaic plant side, wherein
Information of voltage is including but not limited to three-phase voltage and voltage between phases, wherein three-phase voltage refers specifically to A phase voltage, B phase electricity
Pressure, C phase voltage, voltage between phases refer specifically to AB voltage between phases, BC voltage between phases, CA voltage between phases.Line fault is occurring
When, the memory cell in the protection installation place (at M) of photovoltaic plant side will record lower M and be in electricity before failure and when failure
Information is pressed, the memory cell positioned at the protection installation place (at N) of synchronised grids side will record lower N and be in front of failure and when failure
Information of voltage.
Therefore, when breaking down on the transmission line of electricity of photovoltaic plant, phase selection element can be from positioned at photovoltaic plant side
It protects and obtains three-phase voltage of the protection installation place (at M) of photovoltaic plant side before failure in the memory cell of installation place (at M)
And voltage between phases, i.e. acquisition M are in the A phase voltage before failureB phase voltageC phase voltageAB phase phase voltageBC phase phase voltageCA phase phase voltageAnd the protection installation of photovoltaic plant side is obtained from the memory cell
Locate the three-phase voltage and voltage between phases of (at M) in failure, i.e. acquisition M is in A phase voltage when failureB phase voltageC phase voltageAB phase phase voltageBC phase phase voltageCA phase phase voltageWherein, [1] represents event
When barrier, before [0] representing fault.
S12: phase voltage Sudden Changing Rate and the positive sequence false voltage component of A phase voltage, negative phase-sequence failure are obtained using three-phase voltage
Component of voltage and zero-sequence fault component of voltage, and voltage between phases Sudden Changing Rate is obtained using voltage between phases.
After getting the information of voltage of protection installation place of photovoltaic plant side, then it can use protection installation place (i.e. M
Place) three-phase voltage in failure, the three-phase voltage before failure obtain phase voltage Sudden Changing Rate, and obtain A phase voltage positive sequence therefore
The phase before voltage between phases and failure when hindering component of voltage, negative sequence voltage components and zero sequence voltage component, and can use failure
Between voltage obtain voltage between phases Sudden Changing Rate, in order to it is subsequent can according to the information of voltage being calculated accurately and efficiently into
Row fault type judges.
S13: positive sequence voltage obtained according to the positive sequence voltage amplitude of A phase, the rated voltage amplitude of A phase before failure fall be
Number, judges whether positive sequence voltage Drop coefficient is more than or equal to preset threshold；
If positive sequence voltage Drop coefficient is more than or equal to preset threshold, S14 is thened follow the steps, if positive sequence voltage Drop coefficient is small
In preset threshold, S15 is thened follow the steps.
Before line fault occurs or after line fault occurs, the positive sequence voltage amplitude of A phase before available failure
UMa1, and the rated voltage amplitude U of available A phases, then, utilize kλ=UMa1/UsObtain positive sequence voltage Drop coefficient kλ。
Calculating positive sequence voltage Drop coefficient kλIt later, then can be by positive sequence voltage Drop coefficient kλWith preset threshold into
Row compares, if positive sequence voltage Drop coefficient kλMore than or equal to preset threshold, S14 is thened follow the steps, that is, enters each sequence failure of voltage
The phase relation phase selection mode of component, if positive sequence voltage Drop coefficient kλLess than preset threshold, S15 is thened follow the steps, that is, is entered
Voltage failure component amplitude relationship phase selection mode, can accurately and rapidly identify fault type in the event of a failure, with for
Distance protection and from reclosing it is correct effect lay the foundation.
S14: pass through positive sequence false voltage component, negative phase-sequence false voltage component and the zero-sequence fault component of voltage of A phase voltage
Phase relation is obtained, and fault type is determined by phase relation and negative phase-sequence false voltage component, zero-sequence fault component of voltage.
The phase relation phase selection mode of above-mentioned mentioned each sequence fault component of voltage is are as follows: it is electric to pass through obtained A phase
Positive sequence false voltage component, negative phase-sequence false voltage component and the zero-sequence fault voltage of pressure obtain the phase relation between this three,
Then, fault type is determined by negative phase-sequence false voltage component, the zero-sequence fault component of voltage of phase relation and A phase voltage.Its
In, identified fault type not only includes failure mode occurred, but also includes the specifically failure that is occurred of which phase
(include failure phase) copes with failure in order to use corresponding movement, so that it is guaranteed that the safe and stable operation of power grid.
S15: obtaining phase voltage magnitude relation by phase voltage Sudden Changing Rate, obtains voltage between phases by voltage between phases Sudden Changing Rate
Magnitude relation, and fault type is determined by phase voltage magnitude relation, voltage between phases magnitude relation and zero-sequence fault component of voltage.
Above-mentioned mentioned voltage failure component amplitude relationship phase selection mode is are as follows: passes through this three-phase phase of A phase, B phase, C phase
Voltage jump amount obtains phase voltage magnitude relation, and obtains voltage between phases by the voltage between phases Sudden Changing Rate of AB phase, BC phase, CA phase
Then magnitude relation passes through the zero-sequence fault voltage point of phase voltage magnitude relation, voltage between phases magnitude relation and A phase voltage
It measures and determines fault type.
Above-mentioned technical proposal disclosed in the present application, obtain the protection installation place of photovoltaic plant side before failure with failure when
Three-phase voltage, and voltage between phases of the protection installation place before failure and when failure is obtained, it is obtained using three-phase voltage and voltage between phases
To positive sequence false voltage component, the negative phase-sequence false voltage component and zero of phase voltage Sudden Changing Rate, voltage between phases Sudden Changing Rate and A phase voltage
Sequence false voltage component, and the calculated positive sequence voltage Drop coefficient of institute is compared with preset threshold, when positive sequence voltage falls
When falling coefficient more than or equal to preset threshold, pass through positive sequence false voltage component, negative phase-sequence false voltage component and the zero sequence of A phase voltage
The phase relation and negative phase-sequence false voltage component of false voltage component, zero-sequence fault component of voltage determine fault type, work as positive sequence
When Voltage Drop coefficient is less than or equal to preset value, pass through phase voltage magnitude relation, voltage between phases magnitude relation and zero-sequence fault electricity
Component is pressed to determine fault type.Since influence of the photovoltaic plant when accessing power grid to voltage is smaller, pass through photovoltaic electric
Stand side protection installation place voltage condition accurately identifying for the alternating current circuit fault type being connected with photovoltaic plant then may be implemented,
So as to ensure the safe and stable operation of power grid.
A kind of phase-selecting method of photovoltaic plant access power grid provided in an embodiment of the present invention, obtains mutually electricity using three-phase voltage
Positive sequence false voltage component, negative phase-sequence false voltage component and the zero-sequence fault component of voltage of Sudden Changing Rate and A phase voltage are pressed, and is utilized
Voltage between phases obtains voltage between phases Sudden Changing Rate, may include:
Utilize A phase voltage when failureB phase voltageC phase voltageAnd A phase voltage before failureB phase electricity
PressureC phase voltageAccording toCalculate separately A phase phase voltage Sudden Changing RateB phase phase voltage is prominent
VariableC phase phase voltage Sudden Changing RateWherein, M is the protection installation place of photovoltaic plant side；
According toA phase voltage positive-sequence component when calculating separately failureFailure
Preceding A phase voltage positive-sequence componentA phase voltage negative sequence component when failureA phase voltage zero-sequence component when failureAnd
According toObtain the positive sequence false voltage component of A phase voltageAccording toObtain A phase electricity
The negative phase-sequence false voltage component of pressureAccording toObtain the zero-sequence fault component of voltage of A phase voltageWherein,
α=ej120°；
Utilize AB phase phase voltage when failureBC phase phase voltageCA phase phase voltageAnd AB phase phase before failure
VoltageBC phase phase voltageCA phase phase voltageAccording toCalculate separately AB Xiang Xiang electricity
Pressure mutation componentBC phase phase voltage is mutated componentCA phase phase voltage is mutated component
In positive sequence false voltage component, the negative phase-sequence failure electricity for obtaining phase voltage Sudden Changing Rate and A phase voltage using three-phase voltage
It, specifically can be by as follows when pressing component and zero-sequence fault component of voltage, and obtaining voltage between phases Sudden Changing Rate using voltage between phases
Mode obtains:
Getting the A phase voltage at M before failureB phase voltageC phase voltageAnd M is in failure
When A phase voltageB phase voltageC phase voltageLater, then basisCalculate separately A phase phase
Voltage jump amountB phase phase voltage Sudden Changing RateC phase phase voltage Sudden Changing Rate
In addition, after three-phase voltage when getting at M before failure and failure, then it can basisA phase voltage positive-sequence component before calculating failureWherein, α=ej120°, specifically,
UtilizeIt is calculatedIt should be noted that since A phase being not present before failure
Voltage negative sequence component and A phase voltage zero-sequence component, i.e., the A phase voltage negative sequence component before failureZero sequence voltage component
It is 0, therefore, then does not need to calculate by above-mentioned formulaWith
Meanwhile A phase voltage positive-sequence component when can calculate failure according to above-mentioned formulaA phase voltage negative phase-sequence when failure
ComponentA phase voltage zero-sequence component when failureSpecifically, then above-mentioned formula can be transformed toCome A phase voltage positive-sequence component when calculating separately failureA phase voltage when failure
Negative sequence componentWith A phase voltage zero-sequence component when failureThen, then it can useIt calculates
To the positive sequence false voltage component of A phase voltageIt utilizesThe negative phase-sequence false voltage of A phase voltage is calculated
ComponentIt utilizesThe zero-sequence fault component of voltage of A phase voltage is calculated
Getting the AB phase phase voltage at M before failureBC phase phase voltageCA phase phase voltageWith
And AB phase phase voltage of M when being in failureBC phase phase voltageCA phase phase voltageLater, then it can useCalculate separately AB phase phase voltage mutation componentBC phase phase voltage is mutated componentCA
Phase phase voltage is mutated component
So far, then available A phase phase voltage Sudden Changing RateB phase phase voltage Sudden Changing RateC phase phase voltage is prominent
VariableThe positive sequence false voltage component of A phase voltageThe negative phase-sequence false voltage component of A phase voltageA phase electricity
The zero-sequence fault component of voltage of pressureAB phase phase voltage is mutated componentBC phase phase voltage is mutated componentCA
Phase phase voltage is mutated componentIn order to which subsequent these information of voltage that can use carry out fault type judges.
Referring to Fig. 3 to Fig. 5, wherein Fig. 3 shows judgement k provided in an embodiment of the present inventionλWith the relationship of preset threshold and
The flow chart of fault type judges is carried out, Fig. 4 shows voltage sequence fault component phase selection element provided in an embodiment of the present invention
γ block plan, Fig. 5 show the β block plan of voltage sequence fault component phase selection element provided in an embodiment of the present invention.The present invention is real
The phase-selecting method for applying a kind of photovoltaic plant access power grid of example offer, passes through the positive sequence false voltage component of A phase voltage, negative phase-sequence event
Barrier component of voltage and zero-sequence fault component of voltage obtain phase relation, and pass through phase relation and negative phase-sequence false voltage component, zero
Sequence false voltage component determines fault type, may include:
It utilizesCalculate separately γ and β, wherein arg () indicates to take the width of phasor
Angle；
JudgementWhether 0 is equal to, wherein indicate to take the amplitude of voltage phasor；
IfEqual to 0, then judgeWhether 0 is equal to, ifEqual to 0, then it is determined as three phase short circuit fault, ifNot equal to 0, then the section of β is judged: if 0 ° of -120 °≤β <, is determined as AB phase fault；If 240 ° of 120 °≤β <,
Then it is determined as BC phase fault；If 120 ° of 0 °≤β <, is determined as CA phase fault；
IfNot equal to 0, then fault type is determined by γ and β: if γ ∈ (- 30 °, 30 °) and β ∈ (- 60 °,
60 °), then it is determined as A phase ground fault；If γ ∈ (90 °, 150 °) and β ∈ (- 180 °, -60 °), then it is determined as that B phase is grounded event
Barrier；If γ ∈ (- 150 °, -90 °) and β ∈ (60 °, 180 °), then be determined as C phase ground fault；If γ ∈ (- 150 °, -30 °) and
β ∈ (- 120 °, 0 °), then be determined as AB phase ground fault；If γ ∈ (- 30 °, 90 °) and β ∈ (120 °, 240 °), then be determined as
BC phase ground fault；If γ ∈ (90 °, 210 °) and β ∈ (0 °, 120 °), then be determined as CA phase ground fault.
Fault type is determined by negative phase-sequence false voltage component, the zero-sequence fault component of voltage of phase relation and A phase voltage
Detailed process can be with are as follows:
γ and β are calculated separately using aforementioned obtained information of voltage, wherein
Arg () indicates to take the argument of phasor.
JudgementWhether 0 is equal to, wherein indicate to take the amplitude of voltage phasor: ifThen judgeWhether
Equal to 0, ifThen it is determined as three phase short circuit fault, ifThe judgement of fault type, tool are then carried out according to β
Body, if 0 ° of -120 °≤β <, is determined as AB phase fault；If 240 ° of 120 °≤β <, is determined as BC phase fault；If
120 ° of 0 °≤β <, then be determined as CA phase fault；IfSentencing for fault type is then carried out according to γ and β simultaneously
It is fixed, specifically, if γ ∈ (- 30 °, 30 °) and β ∈ (- 60 °, 60 °), then be determined as A phase ground fault；If γ ∈ (90 °,
150 °) and β ∈ (- 180 °, -60 °), then it is determined as B phase ground fault；If γ ∈ (- 150 °, -90 °) and β ∈ (60 °, 180 °),
Then it is determined as C phase ground fault；If γ ∈ (- 150 °, -30 °) and β ∈ (- 120 °, 0 °), then be determined as AB phase ground fault；If
γ ∈ (- 30 °, 90 °) and β ∈ (120 °, 240 °), then be determined as BC phase ground fault；If γ ∈ (90 °, 210 °) and β ∈ (0 °,
120 °), then it is determined as CA phase ground fault.
I.e. in positive sequence voltage Drop coefficient kλIt, can through the above way accurately and rapidly when more than or equal to preset threshold
Fault type is determined, is laid the foundation so as to the correct movement for distance protection and from reclosing.
Referring to Fig. 3 to Fig. 5.A kind of phase-selecting method of photovoltaic plant access power grid provided in an embodiment of the present invention, passes through phase
Voltage jump measures phase voltage magnitude relation, obtains voltage between phases magnitude relation by voltage between phases Sudden Changing Rate, and pass through phase
Voltage magnitude relationship, voltage between phases magnitude relation and zero-sequence fault component of voltage determine fault type, may include:
It utilizesIt calculates separately
m1、m2、m3、n1、n2、n3；
JudgementWhether 0 is equal to, wherein indicate to take the amplitude of voltage phasor；
IfEqual to 0, then n is judged2And n3Whether (n is met2>z)&(1/n3> z), if so, being determined as that AB is alternate short
Road failure；Judge n3And n1Whether (n is met3>z)&(1/n1> z), if so, being determined as BC phase fault；Judge n1And n2Whether
Meet (n1>z)&(1/n2> z), if so, being determined as CA phase fault；If n1、n2、n3(n is not satisfied2>z)&(1/n3>z)、
(n3>z)&(1/n1>z)、(n1>z)&(1/n2> z), then it is determined as three phase short circuit fault, wherein z=4~8；
IfNot equal to 0, then m is judged1And m2Whether (m is met1>z)&(1/m2> z), if so, being determined as that A phase is grounded
Failure；Judge m2And m3Whether (m is met2>z)&(1/m3> z), if so, being determined as B phase ground fault；Judge m1And m3Whether
Meet (m3>z)&(1/m1> z), if so, being determined as C phase ground fault；
If m1、m2、m3(m is not satisfied1>z)&(1/m2>z)、(m2>z)&(1/m3>z)、(m3>z)&(1/m1> z), then determine
For double earthfault, wherein the two-phase in double earthfault isMiddle amplitude is biggish
Two-phase.
Phase voltage magnitude relation, voltage between phases magnitude relation are obtained, and passes through phase voltage magnitude relation, voltage between phases amplitude
Relationship and zero-sequence fault component of voltage determine that the detailed process of fault type can be with are as follows:
M is calculated using aforementioned obtained information of voltage1、m2、m3、n1、n2、n3, wherein
JudgementWhether 0 is equal to, ifThen judge n1、n2、n3Whether expression formula about n is met, if n1、
n2、n3Meet the expression formula about n, then phase-to phase fault phase is judged according to the expression formula of n, if n1、n2、n3It is not satisfied about n's
Expression formula is then determined as three phase short circuit fault.Specifically, judge n2And n3Whether (n is met2>z)&(1/n3> z), if so, sentencing
It is set to AB phase fault；Judge n3And n1Whether (n is met3>z)&(1/n1> z), if so, being determined as BC phase fault；
Judge n1And n2Whether (n is met1>z)&(1/n2> z), if so, being determined as CA phase fault；If n1、n2、n3(n is not satisfied2>
z)&(1/n3>z)、(n3>z)&(1/n1>z)、(n1>z)&(1/n2> z), then it is determined as three phase short circuit fault, wherein z=4~8.
IfThen judge m1、m2、m3Whether expression formula about m is met, if m1、m2、m3Meet the table about m
Up to formula, then singlephase earth fault is judged according to the expression formula of m.Specifically, judge m1And m2Whether (m is met1>z)&(1/m2> z),
If so, being determined as A phase ground fault；Judge m2And m3Whether (m is met2>z)&(1/m3> z), if so, being determined as that B connects
Earth fault；Judge m1And m3Whether (m is met3>z)&(1/m1> z), if so, being determined as C phase ground fault.
If m1、m2、m3It is unsatisfactory for the expression formula about m, even m1、m2、m3(m is not satisfied1>z)&(1/m2>z)、(m2>
z)&(1/m3>z)、(m3>z)&(1/m1> z), then the biggish two-phase of amplitude is determined according to the size of three-phase phase voltage Sudden Changing Rate amplitude
For double earthfault.Specifically, ifThen it is determined as AB phase ground fault；
IfThen it is determined as BC phase ground fault；IfThen it is determined as CA phase ground fault.
I.e. in positive sequence voltage Drop coefficient kλWhen less than preset threshold, can accurately and rapidly it determine through the above way
Be out of order type, lays the foundation so as to the correct movement for distance protection and from reclosing.
A kind of phase-selecting method of photovoltaic plant access power grid provided in an embodiment of the present invention, preset threshold is [0.8,0.9]
In any value.
By positive sequence voltage Drop coefficient kλWhen being compared with preset threshold, set preset threshold is specifically as follows
Any value in [0.8,0.9], to improve the accuracy of identification fault type.
It is of course also possible to adjust the size of preset threshold, according to Voltage Drop situation to improve identification fault type
Accuracy.
Above scheme is illustrated in order to become apparent from, and in order to verify the correctness of above scheme, then to above-mentioned photovoltaic
The phase-selecting method that power grid is accessed in power station carries out analogue simulation.Specifically, it is used in electromagnetic transient simulation software PSCAD/EMTDC
Fortran language realizes analogue simulation, wherein simulation parameters are as follows: photovoltaic plant capacity is 150MW, altogether includes 7
35kV collects route, and main transformer rated capacity is 200MVA, nominal transformation ratio 230/37kV, YNd11 wiring group, short-circuit impedance
16%；The submitting line voltage distribution grade of photovoltaic plant is 220kV, total line length 35km, wherein unit length positive sequence, zero
Sequence impedance is respectively (0.0165+j0.386) Ω/km, (0.04+j0.65) Ω/km.
For the correctness for verifying above-mentioned phase-selecting method, it is assumed that simulation model is at the t=1s moment in photovoltaic plant transmission line of electricity
A phase ground fault occurs at the f of midpoint, trouble duration 0.3s, fault resstance is set to 1 Ω and 100 Ω respectively, obtained
Simulation result is as shown in Figure 6 and Figure 7, wherein Fig. 6 is that the A that resistance is 1 Ω that breaks down at photovoltaic plant transmission line of electricity f connects
Magnitude relation figure when earth fault, the figure being located above in Fig. 6 is that obtained positive sequence voltage amplitude figure is sampled at M, at this point, through counting
Its positive sequence voltage Drop coefficient is calculated less than preset threshold, therefore selects to enter voltage failure component amplitude relationship phase selection mode, in Fig. 6
Underlying figure be phase voltage fault component magnitude relation figure (Curve withCurve almost coincide), will
It is brought intoIn can obtain, the phase-selecting method can accurately determine occur fault type
For A phase ground fault, wherein in Fig. 6It is as above-mentioned to refer toIt is as above-mentioned to refer toIt is as above-mentioned to refer toIt is 100 Ω that Fig. 7, which is the resistance that breaks down at photovoltaic plant transmission line of electricity f,
A phase ground fault when each sequence fault component phase diagram, the figure being located above in Fig. 7 is that obtained positive sequence is sampled at M
Voltage magnitude figure at this point, positive sequence voltage Drop coefficient is greater than preset threshold, therefore selects the phase for entering each sequence fault component of voltage
Relationship phase selection mode, underlying figure is sequence voltage argument figure (negative phase-sequence curve is almost overlapped with zero sequence curve) in Fig. 7, is calculated
The angle of γ and β, by the phase distribution situation analysis of γ and β in Fig. 4 and Fig. 5 it is found that the phase-selecting method can accurately be sentenced
The disconnected fault type occurred out is A phase ground fault.
It can be seen from the above, no matter the failure of which kind of depth occurs for photovoltaic plant transmission line of electricity, the phase-selecting method of the application is equal
Fault type can be recognized accurately, therefore, then effectively improve the reliability and sensitivity of protection.
The embodiment of the invention also provides a kind of phase selection devices of photovoltaic plant access power grid, and referring to Fig. 8, it illustrates this
A kind of photovoltaic plant that inventive embodiments provide accesses the structural schematic diagram of the phase selection device of power grid, may include:
Obtain module 11, for obtain respectively the protection installation place of photovoltaic plant side before failure with three-phase electricity when failure
Voltage between phases before pressure and failure and when failure；
Computing module 12, for obtaining the positive sequence false voltage point of phase voltage Sudden Changing Rate and A phase voltage using three-phase voltage
Amount, negative phase-sequence false voltage component and zero-sequence fault component of voltage, and voltage between phases Sudden Changing Rate is obtained using voltage between phases；
Judgment module 13, for obtaining positive sequence according to the positive sequence voltage amplitude of A phase, the rated voltage amplitude of A phase before failure
Voltage Drop coefficient, judges whether positive sequence voltage Drop coefficient is more than or equal to preset threshold；
First determining module 14, for when judgment module, which is determined as, is, then passing through the positive sequence false voltage of A phase voltage point
Amount, negative phase-sequence false voltage component and zero-sequence fault component of voltage obtain phase relation, and pass through phase relation and negative phase-sequence failure electricity
Pressure component, zero-sequence fault component of voltage determine fault type；
Second determining module 15, for when judgment module is determined as no, then obtaining phase voltage by phase voltage Sudden Changing Rate
Magnitude relation obtains voltage between phases magnitude relation by voltage between phases Sudden Changing Rate, and passes through phase voltage magnitude relation, voltage between phases
Magnitude relation and zero-sequence fault component of voltage determine fault type.
A kind of phase selection device of photovoltaic plant access power grid provided in an embodiment of the present invention, computing module 12 may include:
First computing unit, for utilizing A phase voltage when failureB phase voltageC phase voltageAnd A before failure
Phase voltageB phase voltageC phase voltageAccording toCalculate separately A phase phase voltage Sudden Changing RateB phase phase voltage Sudden Changing RateC phase phase voltage Sudden Changing RateWherein, M is that the protection of photovoltaic plant side is installed
Place；
Second computing unit is used for basisA phase voltage when calculating separately failure
Positive-sequence componentA phase voltage positive-sequence component before failureA phase voltage negative sequence component when failureA phase electricity when failure
Press zero-sequence componentAnd according toObtain the positive sequence false voltage component of A phase voltageAccording toObtain the negative phase-sequence false voltage component of A phase voltageAccording toObtain the zero-sequence fault of A phase voltage
Component of voltageWherein, α=ej120°；
Third computing unit, for utilizing AB phase phase voltage when failureBC phase phase voltageCA phase phase voltageAnd AB phase phase voltage before failureBC phase phase voltageCA phase phase voltageAccording toCalculate separately AB phase phase voltage mutation componentBC phase phase voltage is mutated componentCA
Phase phase voltage is mutated component
A kind of phase selection device of photovoltaic plant access power grid provided in an embodiment of the present invention, the first determining module 14 can wrap
It includes:
4th computing unit, for utilizingCalculate separately γ and β, wherein arg
() indicates to take the argument of phasor；
First judging unit, for judgingWhether 0 is equal to, wherein indicate to take the amplitude of voltage phasor；
First judging unit, if forEqual to 0, then judgeWhether 0 is equal to, ifEqual to 0, then determine
For three phase short circuit fault, ifNot equal to 0, then the section of β is judged: if 0 ° of -120 °≤β <, being determined as that AB is alternate short
Road；If 240 ° of 120 °≤β <, is determined as BC phase fault；If 120 ° of 0 °≤β <, is determined as CA phase fault；
Second judging unit, if forNot equal to 0, then fault type is determined by γ and β: if γ ∈ (- 30 °,
30 °) and β ∈ arg (- 60 °, 60 °), then it is determined as A phase ground fault；If γ ∈ (- 30 °, 30 °) and β ∈ (- 60 °, 60 °), then
It is determined as A phase ground fault；If γ ∈ (90 °, 150 °) and β ∈ (- 180 °, -60 °), then be determined as B phase ground fault；If γ
∈ (- 150 °, -90 °) and β ∈ (60 °, 180 °), then be determined as C phase ground fault；If γ ∈ (- 150 °, -30 °) and β ∈ (-
120 °, 0 °), then it is determined as AB phase ground fault；If γ ∈ (- 30 °, 90 °) and β ∈ (120 °, 240 °), then be determined as that BC connects
Earth fault；If γ ∈ (90 °, 210 °) and β ∈ (0 °, 120 °), then be determined as CA phase ground fault.
In addition, a kind of phase selection equipment of photovoltaic plant access power grid provided in an embodiment of the present invention, the second determining module 15
May include:
5th computing unit, for utilizing Calculate separately m1、m2、m3、n1、n2、n3；
Second judgment unit, for judgingWhether 0 is equal to, wherein indicate to take the amplitude of voltage phasor；
Third judging unit, if forEqual to 0, then n is judged2And n3Whether (n is met2>z)&(1/n3> z), if so,
Then it is determined as AB phase fault；Judge n3And n1Whether (n is met3>z)&(1/n1> z), if so, being determined as that BC is alternate short
Road；Judge n1And n2Whether (n is met1>z)&(1/n2> z), if so, being determined as CA phase fault；If n1、n2、n3It is not satisfied
(n2>z)&(1/n3>z)、(n3>z)&(1/n1>z)、(n1>z)&(1/n2> z), then it is determined as three phase short circuit fault, wherein z=4
~8；
4th judging unit, if forNot equal to 0, then m is judged1And m2Whether (m is met1>z)&(1/m2> z), if
It is then to be determined as A phase ground fault；Judge m2And m3Whether (m is met2>z)&(1/m3> z), if so, being determined as that B phase is grounded
Failure；Judge m1And m3Whether (m is met3>z)&(1/m1> z), if so, being determined as C phase ground fault；
5th judging unit, if being used for m1、m2、m3(m is not satisfied1>z)&(1/m2>z)、(m2>z)&(1/m3>z)、(m3>
z)&(1/m1> z), then it is determined as double earthfault, wherein the two-phase in double earthfault isThe middle biggish two-phase of amplitude.
The embodiment of the invention also provides a kind of phase selection equipment of photovoltaic plant access power grid, and referring to Fig. 9, it illustrates this
A kind of photovoltaic plant that inventive embodiments provide accesses the structural schematic diagram of the phase selection equipment of power grid, may include:
Memory 21, for storing computer program；
Processor 22 realizes the phase selection side such as above-mentioned any photovoltaic plant access power grid when for executing computer program
The step of method.
The embodiment of the invention also provides a kind of computer readable storage medium, it is stored on computer readable storage medium
Computer program realizes the phase-selecting method of any of the above-described kind of photovoltaic plant access power grid when computer program is executed by processor
Step.
Phase selection device, equipment and the computer-readable storage of a kind of photovoltaic plant access power grid provided in an embodiment of the present invention
The explanation of relevant portion refers to the choosing to install in method of a kind of photovoltaic plant access power grid provided in an embodiment of the present invention in medium
The detailed description of corresponding part, details are not described herein.
It should be noted that, in this document, relational terms such as first and second and the like are used merely to a reality
Body or operation are distinguished with another entity or operation, are deposited without necessarily requiring or implying between these entities or operation
In any actual relationship or order or sequence.Moreover, the terms "include", "comprise" or its any other variant are intended to
Non-exclusive inclusion, so that the element that the process, method, article or equipment including a series of elements is intrinsic.?
Do not have in the case where more limiting, the element limited by sentence "including a ...", it is not excluded that including the element
There is also other identical elements in process, method, article or equipment.In addition, above-mentioned technology provided in an embodiment of the present invention
In scheme with correspond to the consistent part of technical solution realization principle and unspecified in the prior art, in order to avoid excessively repeat.
The foregoing description of the disclosed embodiments can be realized those skilled in the art or using the present invention.To this
A variety of modifications of a little embodiments will be apparent for a person skilled in the art, and the general principles defined herein can
Without departing from the spirit or scope of the present invention, to realize in other embodiments.Therefore, the present invention will not be limited
It is formed on the embodiments shown herein, and is to fit to consistent with the principles and novel features disclosed in this article widest
Range.
Claims (10)
1. a kind of phase-selecting method of photovoltaic plant access power grid characterized by comprising
Respectively before three-phase voltage and failure of the protection installation place of acquisition photovoltaic plant side before failure and when failure and when failure
Voltage between phases；
Positive sequence false voltage component, the negative phase-sequence false voltage of phase voltage Sudden Changing Rate and A phase voltage are obtained using the three-phase voltage
Component and zero-sequence fault component of voltage, and voltage between phases Sudden Changing Rate is obtained using the voltage between phases；
Positive sequence voltage Drop coefficient is obtained according to the positive sequence voltage amplitude of A phase, the rated voltage amplitude of A phase before failure, judges institute
State whether positive sequence voltage Drop coefficient is more than or equal to preset threshold；
If so, positive sequence false voltage component, the negative phase-sequence false voltage component and the zero sequence event for passing through the A phase voltage
Barrier component of voltage obtains phase relation, and passes through the phase relation and the negative phase-sequence false voltage component, the zero-sequence fault
Component of voltage determines fault type；
If it is not, then obtaining phase voltage magnitude relation by the phase voltage Sudden Changing Rate, obtained by the voltage between phases Sudden Changing Rate
Voltage between phases magnitude relation, and pass through the phase voltage magnitude relation, the voltage between phases magnitude relation and the zero-sequence fault
Component of voltage determines fault type.
2. the phase-selecting method of photovoltaic plant access power grid according to claim 1, which is characterized in that utilize the three-phase electricity
Pressure obtains positive sequence false voltage component, negative phase-sequence false voltage component and the zero-sequence fault voltage of phase voltage Sudden Changing Rate and A phase voltage
Component, and voltage between phases Sudden Changing Rate is obtained using the voltage between phases, comprising:
Utilize A phase voltage when failureB phase voltageC phase voltageAnd A phase voltage before failureB phase voltageC phase voltageAccording toCalculate separately A phase phase voltage Sudden Changing RateThe mutation of B phase phase voltage
AmountC phase phase voltage Sudden Changing RateWherein, M is the protection installation place of photovoltaic plant side；
According toA phase voltage positive-sequence component when calculating separately failureA before failure
Phase voltage positive-sequence componentA phase voltage negative sequence component when failureA phase voltage zero-sequence component when failureAnd according toObtain the positive sequence false voltage component of A phase voltageAccording toObtain A phase voltage
Negative phase-sequence false voltage componentAccording toObtain the zero-sequence fault component of voltage of A phase voltageWherein, α
=ej120°；
Utilize AB phase phase voltage when failureBC phase phase voltageCA phase phase voltageAnd AB phase phase voltage before failureBC phase phase voltageCA phase phase voltageAccording toCalculate separately AB phase phase voltage
It is mutated componentBC phase phase voltage is mutated componentCA phase phase voltage is mutated component
3. the phase-selecting method of photovoltaic plant access power grid according to claim 2, which is characterized in that pass through the A phase electricity
Positive sequence false voltage component, the negative phase-sequence false voltage component and the zero-sequence fault component of voltage of pressure obtain phase relation,
And fault type is determined by the phase relation and the negative phase-sequence false voltage component, the zero-sequence fault component of voltage, it wraps
It includes:
It utilizesCalculate separately γ and β, wherein arg () indicates to take the argument of phasor；
JudgementWhether 0 is equal to, wherein | | it indicates to take the amplitude of voltage phasor；
IfEqual to 0, then judgeWhether 0 is equal to, ifEqual to 0, then it is determined as three phase short circuit fault, ifNot equal to 0, then the section of β is judged: if 0 ° of -120 °≤β <, is determined as AB phase fault；If 240 ° of 120 °≤β <,
Then it is determined as BC phase fault；If 120 ° of 0 °≤β <, is determined as CA phase fault；
IfNot equal to 0, then fault type is determined by γ and β: if γ ∈ (- 30 °, 30 °) and β ∈ (- 60 °, 60 °), then
It is determined as A phase ground fault；If γ ∈ (90 °, 150 °) and β ∈ (- 180 °, -60 °), then be determined as B phase ground fault；If γ
∈ (- 150 °, -90 °) and β ∈ (60 °, 180 °), then be determined as C phase ground fault；If γ ∈ (- 150 °, -30 °) and β ∈ (-
120 °, 0 °), then it is determined as AB phase ground fault；If γ ∈ (- 30 °, 90 °) and β ∈ (120 °, 240 °), then be determined as that BC connects
Earth fault；If γ ∈ (90 °, 210 °) and β ∈ (0 °, 120 °), then be determined as CA phase ground fault.
4. the phase-selecting method of photovoltaic plant access power grid according to claim 2, which is characterized in that pass through the phase voltage
Sudden Changing Rate obtains phase voltage magnitude relation, obtains voltage between phases magnitude relation by the voltage between phases Sudden Changing Rate, and pass through institute
It states phase voltage magnitude relation, the voltage between phases magnitude relation and the zero-sequence fault component of voltage and determines fault type, comprising:
It utilizes
Calculate separately m1、m2、m3、n1、n2、n3；
JudgementWhether 0 is equal to, wherein | | it indicates to take the amplitude of voltage phasor；
IfEqual to 0, then n is judged2And n3Whether (n is met2>z)&(1/n3> z), if so, being determined as the event of AB phase fault
Barrier；Judge n3And n1Whether (n is met3>z)&(1/n1> z), if so, being determined as BC phase fault；Judge n1And n2Whether meet
(n1>z)&(1/n2> z), if so, being determined as CA phase fault；If n1、n2、n3(n is not satisfied2>z)&(1/n3>z)、(n3>
z)&(1/n1>z)、(n1>z)&(1/n2> z), then it is determined as three phase short circuit fault, wherein z=4~8；
IfNot equal to 0, then m is judged1And m2Whether (m is met1>z)&(1/m2> z), if so, being determined as that A phase is grounded event
Barrier；Judge m2And m3Whether (m is met2>z)&(1/m3> z), if so, being determined as B phase ground fault；Judge m1And m3It is whether full
Foot (m3>z)&(1/m1> z), if so, being determined as C phase ground fault；
If m1、m2、m3(m is not satisfied1>z)&(1/m2>z)、(m2>z)&(1/m3>z)、(m3>z)&(1/m1> z), then it is determined as two
Phase ground fault, wherein the two-phase in the double earthfault isMiddle amplitude is biggish
Two-phase.
5. the phase-selecting method of photovoltaic plant access power grid according to any one of claims 1 to 4, which is characterized in that described
Preset threshold is any value in [0.8,0.9].
6. a kind of phase selection device of photovoltaic plant access power grid characterized by comprising
Module is obtained, for obtaining three-phase voltage of the protection installation place of photovoltaic plant side before failure and when failure and former respectively
Voltage between phases before barrier and when failure；
Computing module, for obtained using the three-phase voltage phase voltage Sudden Changing Rate and A phase voltage positive sequence false voltage component,
Negative phase-sequence false voltage component and zero-sequence fault component of voltage, and voltage between phases Sudden Changing Rate is obtained using the voltage between phases；
Judgment module, for obtaining positive sequence voltage according to the positive sequence voltage amplitude of A phase, the rated voltage amplitude of A phase before failure and falling
Coefficient is fallen, judges whether the positive sequence voltage Drop coefficient is more than or equal to preset threshold；
First determining module, for when the judgment module is judged to being, then passing through the positive sequence false voltage of the A phase voltage
Component, the negative phase-sequence false voltage component and the zero-sequence fault component of voltage obtain phase relation, and are closed by the phase
System and the negative phase-sequence false voltage component, the zero-sequence fault component of voltage determine fault type；
Second determining module, for when the judgment module is determined as no, then obtaining mutually electricity by the phase voltage Sudden Changing Rate
Magnitude relation is pressed, voltage between phases magnitude relation is obtained by the voltage between phases Sudden Changing Rate, and close by the phase voltage amplitude
System, the voltage between phases magnitude relation and the zero-sequence fault component of voltage determine fault type.
7. the phase selection device of photovoltaic plant access power grid according to claim 6, which is characterized in that the computing module packet
It includes:
First computing unit, for utilizing A phase voltage when failureB phase voltageC phase voltageAnd A phase before failure
VoltageB phase voltageC phase voltageAccording toCalculate separately A phase phase voltage Sudden Changing RateB phase phase voltage Sudden Changing RateC phase phase voltage Sudden Changing RateWherein, M is that the protection of photovoltaic plant side is installed
Place；
Second computing unit is used for basisA phase voltage positive sequence when calculating separately failure
ComponentA phase voltage positive-sequence component before failureA phase voltage negative sequence component when failureA phase voltage zero when failure
Order componentsAnd according toObtain the positive sequence false voltage component of A phase voltageAccording toObtain the negative phase-sequence false voltage component of A phase voltageAccording toObtain the zero sequence event of A phase voltage
Hinder component of voltageWherein, α=ej120°；
Third computing unit, for utilizing AB phase phase voltage when failureBC phase phase voltageCA phase phase voltage
And AB phase phase voltage before failureBC phase phase voltageCA phase phase voltageAccording toPoint
It Ji Suan not AB phase phase voltage mutation componentBC phase phase voltage is mutated componentCA phase phase voltage is mutated component
8. the phase selection device of photovoltaic plant access power grid according to claim 7, which is characterized in that described first determines mould
Block includes:
4th computing unit, for utilizingCalculate separately γ and β, wherein arg () table
Show the argument for taking phasor；
First judging unit, for judgingWhether 0 is equal to, wherein | | it indicates to take the amplitude of voltage phasor；
First judging unit, if forEqual to 0, then judgeWhether 0 is equal to, ifEqual to 0, then it is determined as three
Phase short trouble, ifNot equal to 0, then the section of β is judged: if 0 ° of -120 °≤β <, is determined as AB phase fault；If
240 ° of 120 °≤β <, then be determined as BC phase fault；If 120 ° of 0 °≤β <, is determined as CA phase fault；
Second judging unit, if forNot equal to 0, then fault type is determined by γ and β: if γ ∈ (- 30 °, 30 °) and
β ∈ (- 60 °, 60 °), then be determined as A phase ground fault；If γ ∈ (90 °, 150 °) and β ∈ (- 180 °, -60 °), then be determined as B
Phase ground fault；If γ ∈ (- 150 °, -90 °) and β ∈ (60 °, 180 °), then be determined as C phase ground fault；If γ ∈ (-
150 °, -30 °) and β ∈ (- 120 °, 0 °), then it is determined as AB phase ground fault；If γ ∈ (- 30 °, 90 °) and β ∈ (120 °,
240 °), then it is determined as BC phase ground fault；If γ ∈ (90 °, 210 °) and β ∈ (0 °, 120 °), then it is determined as that CA phase is grounded event
Barrier.
9. a kind of phase selection equipment of photovoltaic plant access power grid characterized by comprising
Memory, for storing computer program；
Processor realizes that photovoltaic plant described in any one of claim 1 to 5 such as accesses when for executing the computer program
The step of phase-selecting method of power grid.
10. a kind of computer readable storage medium, which is characterized in that be stored with computer on the computer readable storage medium
Program is realized when the computer program is executed by processor such as photovoltaic plant described in any one of claim 1 to 5 access electricity
The step of phase-selecting method of net.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN110703134A (en) * | 2019-10-15 | 2020-01-17 | 南京国电南自电网自动化有限公司 | Small current grounding line selection and phase selection method based on fault sequence component |
| CN112014684A (en) * | 2020-08-12 | 2020-12-01 | 艾伏新能源科技(上海)股份有限公司 | High-precision detection method for three-phase voltage unbalance drop fault and phase jump fault |
| CN112505586A (en) * | 2020-12-28 | 2021-03-16 | 国网河北省电力有限公司电力科学研究院 | Fault detection method and device for distribution line in photovoltaic grid-connected power generation system |
| CN112698236A (en) * | 2020-12-28 | 2021-04-23 | 深圳供电局有限公司 | Station power failure judgment method and device, computer equipment and storage medium |
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| CN102818973B (en) * | 2012-09-03 | 2014-11-19 | 武汉大学 | Phase sequence voltage amplitude comparison-based failure phase selection method and device |
| JP6350347B2 (en) * | 2015-03-12 | 2018-07-04 | オムロン株式会社 | Isolated operation detection device, power conversion system, and isolated operation detection method |
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| CN110703134A (en) * | 2019-10-15 | 2020-01-17 | 南京国电南自电网自动化有限公司 | Small current grounding line selection and phase selection method based on fault sequence component |
| CN110703134B (en) * | 2019-10-15 | 2022-02-15 | 南京国电南自电网自动化有限公司 | Small current grounding line selection and phase selection method based on fault sequence component |
| CN112014684A (en) * | 2020-08-12 | 2020-12-01 | 艾伏新能源科技(上海)股份有限公司 | High-precision detection method for three-phase voltage unbalance drop fault and phase jump fault |
| CN112014684B (en) * | 2020-08-12 | 2023-04-18 | 艾伏新能源科技(上海)股份有限公司 | High-precision detection method for three-phase voltage unbalance drop fault and phase jump fault |
| CN112505586A (en) * | 2020-12-28 | 2021-03-16 | 国网河北省电力有限公司电力科学研究院 | Fault detection method and device for distribution line in photovoltaic grid-connected power generation system |
| CN112698236A (en) * | 2020-12-28 | 2021-04-23 | 深圳供电局有限公司 | Station power failure judgment method and device, computer equipment and storage medium |
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