CN106786731A - The modeling method of harmonic propagation network in a kind of collector system of large-sized photovoltaic power station - Google Patents
The modeling method of harmonic propagation network in a kind of collector system of large-sized photovoltaic power station Download PDFInfo
- Publication number
- CN106786731A CN106786731A CN201611074065.6A CN201611074065A CN106786731A CN 106786731 A CN106786731 A CN 106786731A CN 201611074065 A CN201611074065 A CN 201611074065A CN 106786731 A CN106786731 A CN 106786731A
- Authority
- CN
- China
- Prior art keywords
- harmonic
- power station
- collector system
- photovoltaic power
- propagation network
- 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
Links
- 238000000034 method Methods 0.000 title claims abstract description 26
- 239000011159 matrix material Substances 0.000 claims description 32
- 238000004804 winding Methods 0.000 claims description 25
- 230000005611 electricity Effects 0.000 claims description 16
- 230000005540 biological transmission Effects 0.000 claims description 15
- 230000015572 biosynthetic process Effects 0.000 claims description 12
- 238000005755 formation reaction Methods 0.000 claims description 12
- 239000013598 vector Substances 0.000 claims description 8
- 239000000203 mixture Substances 0.000 claims description 5
- 238000006243 chemical reaction Methods 0.000 claims description 3
- 239000013589 supplement Substances 0.000 claims description 3
- 238000004364 calculation method Methods 0.000 abstract description 23
- 238000004458 analytical method Methods 0.000 abstract description 11
- 230000003321 amplification Effects 0.000 description 27
- 238000003199 nucleic acid amplification method Methods 0.000 description 27
- 230000008859 change Effects 0.000 description 13
- 241000196324 Embryophyta Species 0.000 description 8
- 238000010586 diagram Methods 0.000 description 7
- 238000002347 injection Methods 0.000 description 6
- 239000007924 injection Substances 0.000 description 6
- 230000000694 effects Effects 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000002964 excitative effect Effects 0.000 description 2
- 241000208340 Araliaceae Species 0.000 description 1
- 244000150187 Cyperus papyrus Species 0.000 description 1
- 235000005035 Panax pseudoginseng ssp. pseudoginseng Nutrition 0.000 description 1
- 235000003140 Panax quinquefolius Nutrition 0.000 description 1
- 238000003491 array Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000011217 control strategy Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 235000008434 ginseng Nutrition 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 230000008676 import Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000000246 remedial effect Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 230000002459 sustained effect Effects 0.000 description 1
Classifications
-
- H02J3/383—
-
- 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]
-
- 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
Landscapes
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The invention discloses the modeling method of harmonic propagation network in a kind of collector system of large-sized photovoltaic power station, comprise the following steps：S1, determines each element for setting up equivalent model that harmonic propagation network is related in the collector system of large-sized photovoltaic power station；S2, for the described each element for determining sets up equivalent model；S3, is equiva lent impedance structure by the collector system thaumatropy of large-sized photovoltaic power station, and the equivalent model according to the equiva lent impedance structure and each element is harmonic propagation network struction equivalent model.The method takes into full account influence of influence and cable data of influence, the parameter of LCL filter of the cable data of collector system in collector system in large-sized photovoltaic power station to frequency analysis result to harmonic flow calculation result to harmonic flow calculation result, improves the authenticity of harmonic propagation network modelling.For the accuracy of follow-up harmonic flow calculation provides good basis.
Description
Technical field
The present invention relates to the modeling method of harmonic propagation network in a kind of collector system of large-sized photovoltaic power station, more particularly to one
Plant the modeling method of harmonic propagation network in the large-sized photovoltaic power station collector system for home energy source.
Background technology
China just accelerating at present the use of the green energy resources such as the construction of resource-conserving and environment-friendly society, electric energy than
Example will be continued to increase, and home energy source is also changed from traditional energy to green energy resource.Present family photovoltaic generation is gradually subject to extensive
Use.Photovoltaic generation is refered in particular to use photovoltaic module, and solar energy is converted directly into the electricity generation system of electric energy.It is a kind of new
, have it is with broad prospects for development generating and comprehensive utilization of energy mode.
2015, China's generation of electricity by new energy maintained sustained and rapid growth, and photovoltaic installed capacity leaps to the world more than Germany first
One.Because China's solar energy resources is mainly enriched in northwestern, apart from load center farther out, it is necessary to remote using high pressure
Transmission of electricity, therefore the scale and maximization of photovoltaic plant have become one of important development trend of photovoltaic industry.
With the continuous growth of family's photovoltaic generation, photovoltaic plant installed capacity explosive growth, large-scale photovoltaic power station
Access and the extensive use of power electronic equipment cause that a large amount of nonlinear loads are also added in power system, to power system
Pollute, power quality problem occur.At present, harmonic problem is one of restriction topmost problem of photovoltaic electric station grid connection, very
Be present harmonic excess in more large-scale grid-connected photovoltaic power station, and more protruded under low illumination service condition.Large-sized photovoltaic power station
In, every group of output current of grid-connected inverter system is outwards sent out after collecting through collector system in station.Even if separate unit parallel network reverse
The output current harmonics of device are smaller, and the harmonic wave of output current is also possible to exceeded after many combining inverter parallel connections.Due to large-scale
Grid-connected photovoltaic power station typically uses LCL filter, and many photovoltaic plants access light current net, filtering by long distance powedr transmission cable
Electric capacity may cause resonance so as to cause some subharmonic to amplify.Therefore, when frequency analysis is carried out to large-scale photovoltaic power station,
Not only to consider increasingly significant between photovoltaic system and power network interaction, it should also consider by wave filter, transformer, cable
The collector system that the elements such as circuit are constituted is to the influence caused by harmonic propagation.
So, effectively modeled by harmonic propagation network in the collector system of large-sized photovoltaic power station, will pass through
Harmonic propagation network after modeling is studied, is realized to harmonic problem and each node each harmonic voltage relative to this
The analyzing and processing of the multiplication factor of point fundamental voltage is very necessary.
The content of the invention
In view of the shortcomings of the prior art, the technical problems to be solved by the invention are to provide a kind of large-sized photovoltaic power station collection
The modeling method of harmonic propagation network in electric system.
For achieving the above object, the present invention uses following technical schemes：
The modeling method of harmonic propagation network, comprises the following steps in a kind of collector system of large-sized photovoltaic power station：
S1, determines each element for setting up equivalent model that harmonic propagation network is related in the collector system of large-sized photovoltaic power station；
S2, for the described each element for determining sets up equivalent model；
S3, is equiva lent impedance structure by the collector system thaumatropy of large-sized photovoltaic power station, according to the equiva lent impedance structure
And the equivalent model of each element is harmonic propagation network struction equivalent model, that is, obtain harmonic propagation network node admittance
Matrix.
Wherein more preferably, in step sl, each element for setting up model includes：The unit included in photovoltaic generation unit
Part, transmission line of electricity and cable, main transformer, high-voltage fence and load.
Wherein more preferably, the element for being included in the photovoltaic generation unit is photovoltaic DC-to-AC converter LCL filter and double divisions
Transformer；
Wherein, the harmonic impedance of the photovoltaic DC-to-AC converter LCL filter is represented with equation below：
Wherein, ZLIt is the harmonic impedance of inductance；XLIt is the fundamental reactance of inductance；H is overtone order；ZcIt is the harmonic wave of electric capacity
Impedance；XcIt is the fundamental reactance of electric capacity, j is conversion coefficient.
Wherein more preferably, the equiva lent impedance of described pair of transformer with split winding is represented with equation below：
Wherein, Xt1It is the fundamental wave equivalent reactance of double transformer with split winding primary side windings；Xt2、Xt3Respectively two vice-side windings
Fundamental wave equivalent reactance, h is overtone order.
Wherein more preferably, the main transformer harmonic impedance model is：
ZT=h1.15RT+hXT
Wherein, ZTIt is main transformer Equivalent Harmonic impedance, RTAnd XTThe equivalent resistance of main transformer and reactance respectively under fundamental wave, h are humorous
Ripple number of times.
Wherein more preferably, equivalent impedance of the high-voltage fence with load under h subharmonic is：
Wherein, Z is the harmonic wave equiva lent impedance of system or load, and R and X is respectively its fundamental wave equivalent resistance and reactance.
Wherein more preferably, in step s 2, it is that harmonic propagation network struction equivalent model is according to harmonic propagation network knot
Structure, obtains bus admittance matrix Y；
Wherein, Y is (6mn+3) rank square formation, makes k=6mn, then have：
In formula, Ya=Yai, the transadmittance in i-th collection electric line of expression between each node and k+1 nodes, Yk+i,
K+i is the self-admittance (i=1,2) of k+i nodes in network；Yk+i, k+j be network between k+i nodes and k+j nodes
Transadmittance (i=1,2, j=1,2, and i ≠ j), Ym is the bus admittance matrix for collecting electric line wall scroll branch road, and Ym is (6n) rank
Square formation, has m Ym matrix in square formation Y.
Wherein more preferably, Ya is (6n × 1) rank column vector, and Ya is represented with equation below：
Wherein more preferably, Ym is the bus admittance matrix for collecting electric line wall scroll branch road, and Ym is represented with equation below：
Wherein, Y1, Y2 are 6 rank square formations, and Y1 is first generator unit of collector system wall scroll branch road and coupled
The bus admittance matrix of cable, Y2 is the node admittance square of remaining each generator unit of this branch road and coupled cable
Battle array, Yc is the supplement matrix of the matrix of Y1, Y2 composition.
Wherein more preferably, in step s3, harmonic electric current and the harmonic propagation net according to each harmonic wave source node
Network bus admittance matrix obtains each node harmonic voltage, that is, harmonic trend is obtained, using equation below：
U (h)=Y-1(h)I(h)
Wherein, U (h) is each node h subharmonic voltage column vectors；Y (h) is the node admittance square that h subharmonic transmits network
Battle array；I (h) is each node h subharmonic Injection Current column vector.
The modeling method of harmonic propagation network in the collector system of large-sized photovoltaic power station provided by the present invention, by being harmonic wave
Each element that transmission network is related to sets up equivalent model and is equiva lent impedance by the collector system thaumatropy of large-sized photovoltaic power station
Structure, is harmonic propagation network struction equivalent model.The method takes into full account in large-sized photovoltaic power station current collection system in collector system
Influence of influence, the parameter of LCL filter of the cable data of system to frequency analysis result to harmonic flow calculation result and
Influence of the cable data to harmonic flow calculation result, improves the authenticity of harmonic propagation network modelling.It is follow-up harmonic wave tide
The accuracy of stream calculation provides good basis.
Brief description of the drawings
Fig. 1 is the flow of the modeling method of harmonic propagation network in the collector system of large-sized photovoltaic power station provided by the present invention
Figure；
Fig. 2 is the structural representation of large-scale grid-connected photovoltaic power station provided by the present invention；
Fig. 3 is the structural representation of collection electric line provided by the present invention；
Fig. 4 is the structural representation of photovoltaic generation unit provided by the present invention；
Fig. 5 is the part-structure schematic diagram of photovoltaic generation unit equiva lent impedance provided by the present invention；
Fig. 6 is the structural representation of large-scale grid-connected photovoltaic power station equiva lent impedance provided by the present invention；
Fig. 7 is the structural representation of current collection line equivalent impedance provided by the present invention；
Fig. 8 is the structural representation in the large-sized photovoltaic power station for ignoring collector system provided by the present invention；
Fig. 9 is in one embodiment provided by the present invention, the displaying of PCC point each harmonic voltage amplifications situation is schemed；
Figure 10 is in one embodiment provided by the present invention, the value of L1 is to PCC point each harmonic voltage amplification situation exhibitions
The schematic diagram for showing；
Figure 11 is in one embodiment provided by the present invention, the value of L2 is to PCC point each harmonic voltage amplification situation exhibitions
The schematic diagram for showing；
Figure 12 is in one embodiment provided by the present invention, the value of C shows to PCC point each harmonic voltage amplifications situation
Schematic diagram；
Figure 13 is in one embodiment provided by the present invention, the value of cable resistance is to PCC point each harmonic voltage amplifications
The schematic diagram of situation displaying；
Figure 14 is in one embodiment provided by the present invention, the value of cable admittance is to PCC point each harmonic voltage amplifications
The schematic diagram of situation displaying.
Specific embodiment
Detailed specific description is carried out to technology contents of the invention with specific embodiment below in conjunction with the accompanying drawings.
As shown in figure 1, the present invention provide large-sized photovoltaic power station collector system in harmonic propagation network modeling method, tool
Body comprises the following steps：First, it is determined that being related to for harmonic propagation network in the large-sized photovoltaic power station collector system of home energy source
The need for set up each element of model；Then, for each element in the harmonic propagation network of determination sets up equivalent model；Finally,
It is equiva lent impedance structure by the thaumatropy of large-sized photovoltaic power station collector system, according to the equivalent of equiva lent impedance structure and each element
Model is harmonic propagation network struction equivalent model, that is, obtain harmonic propagation network node admittance matrix.Below to this process
Do detailed specific description.
S1, it is determined that being set up the need for being related to for harmonic propagation network in the large-sized photovoltaic power station collector system of home energy source
Each element of model.
Large-scale grid-connected photovoltaic power station (large-sized photovoltaic power station collector system) structure is as shown in Figure 2.Large-scale grid-connected photovoltaic power station
Comprising some photovoltaic generation units, as shown in figure 3, the power output of photovoltaic generation unit imports 10kV through collection electric line in station handing over
Stream bus.Assuming that the total m bars of photovoltaic plant collection electric line (current collection line assumption diagram is as shown in Figure 4) in parallel, every collection electric wire
N photovoltaic generation unit composition of route.The electric energy that photovoltaic plant is produced, for the main transformer of 10/121kV boosts, passes through through no-load voltage ratio
Ultra-high-tension power transmission line is incorporated to bulk power grid.The structure of large-scale grid-connected photovoltaic power station, the structure for collecting electric line and photovoltaic generation unit
Structure is this area conventional structure, is just repeated no more herein.
According to the structure of large-sized photovoltaic power station collector system, it is determined that for the large-sized photovoltaic power station collector system of home energy source
Middle harmonic propagation network sets up each element of model the need for being related to.And for each element that harmonic propagation network is related to sets up equivalent
Model.In embodiment provided by the present invention, setting up the element that harmonic propagation network is related to includes：Wrapped in photovoltaic generation unit
Element, transmission line of electricity and cable, main transformer, high-voltage fence (system) and the load for containing.Wherein, included in photovoltaic generation unit
Element be photovoltaic DC-to-AC converter LCL filter and double transformer with split windings.Subsequently each equivalent model is described in detail.
S2, for each element in the harmonic propagation network of determination sets up equivalent model
Preceding to have addressed, in embodiment provided by the present invention, setting up the element that harmonic propagation network is related to includes：Photovoltaic
Element, transmission line of electricity and cable, main transformer, high-voltage fence (system) and the load included in generator unit.Wherein, photovoltaic hair
The element included in electric unit is photovoltaic DC-to-AC converter LCL filter and double transformer with split windings.Each equivalent model is carried out below
Detailed description.
Photovoltaic generation unit structure is converted to the equiva lent impedance structure of photovoltaic generation unit, photovoltaic generation unit it is equivalent
Impedance structure figure is as shown in Figure 5.In photovoltaic generation unit, 2 groups of photovoltaic arrays connect with 2 photovoltaic DC-to-AC converters of 500kW respectively
Connect, the output current of inverter delivers to double transformer with split windings that a no-load voltage ratio is 10.5/0.27/0.27kV after LCL filter,
Then collector system (large-sized photovoltaic power station collector system) in access station.
Using the photovoltaic DC-to-AC converter of current control mode, it is processed as that constant current can be exported in harmonic flow calculation
Current source.The harmonic impedance of photovoltaic DC-to-AC converter LCL filter can be calculated with formula (1).
Wherein, ZLIt is the harmonic impedance of inductance；XLIt is the fundamental reactance of inductance；H is overtone order；ZcIt is the harmonic wave of electric capacity
Impedance；XcIt is the fundamental reactance of electric capacity, j is conversion coefficient.
It is the double of 1000/500/500kVA for 4.5%, rated capacity that photovoltaic generation unit uses short-circuit impedance percentage
Transformer with split winding, ignores the influence of inside transformer impedance, there is Zt=jXt,.If Zt1Represent the equiva lent impedance of high pressure winding, Zt2、
Zt3Two equiva lent impedances of low pressure winding are represented respectively, it is generally the case that the equiva lent impedance of double transformer with split windings can use following formula
Calculate：
In formula, Xt1It is the fundamental wave equivalent reactance of double transformer with split winding primary side windings；Xt2、Xt3Respectively two vice-side windings
Fundamental wave equivalent reactance, X1-2To pass through impedance, KFIt is bundle factor, h is overtone order.
Every group of grid-connected inverter system generally uses identical structure, parameter and control strategy etc. in large-sized photovoltaic power station,
And the model all same of step-up transformer.Therefore, in the present invention, it is assumed that in Fig. 3 in all generator units each element ginseng
Count up to exactly the same.
On transmission line of electricity and cable, when fundamental wave is calculated, transmission line of electricity generally uses π type equivalent circuits.But humorous
During ripple is calculated, due to circuit distribution character than fundamental wave when it is more significantly, thus the circuit that can represent of each π type apart from general greatly
To shorten.Therefore it is more to use distributed constant equivalent circuit in Harmonics Calculation.To make the distributed constant of long transmission line equivalent
Circuit counting is more facilitated, using hyperbolic functions come computing electric power line and the equivalent circuit of cable.Wherein computing electric power line
With the method for the equivalent circuit of cable with reference to paper reed Jingjing, harmonic analysis in power system and program development (China Power science
Research institute, 2005).During h subharmonic, the harmonic parameters of circuit unit length are：
In formula, ZohIt is the unit length harmonic impedance of circuit, rohIt is unit length harmonic wave resistance, X1It is unit length fundamental wave
Reactance, yohIt is unit length harmonic admittance, b1It is unit length fundamental wave susceptance, h is overtone order.In view of kelvin effect, line
The resistance per unit length on road can be calculated by following formula：
In formula, r1It is circuit unit length fundamental wave resistance.
During h subharmonic, length for l transmission line of electricity and cable impedance and admittance value be：
Wherein, ZLhAnd YChThe respectively harmonic impedance of circuit and admittance, sh (x) is hyperbolic sine function, ch (x) hyperbolics
Cosine function；ZChAnd γhRespectively h subharmonic when circuit characteristic impedance and propagation function, ZChAnd γhCan be calculated by following formula
Arrive：
On main transformer, fundamental load flow calculates the excitatory branch for especially ignoring transformer in the calculating of High-Voltage Network, often
Road and winding resistance, the excitatory branch road of transformer are nonlinear due to the presence of iron core, and nonlinear degree is with applied voltage
And change, voltage is higher, and iron core is closer to saturation, and its nonlinear degree is also bigger.It is humorous after applied voltage too high core sataration
Ripple containing ratio is greatly increased, therefore it can be regarded as single harmonic source.In harmonic flow calculation, when the harmonic wave for being considered
When number of times is less high, the effect of turn-to-turn capacitance between negligible Transformer Winding and in winding, thus its equivalent circuit is a connection
The impedance branch of former secondary node, its impedance value is made up of winding resistance and leakage reactance.In the presence of higher hamonic wave, transformer
The kelvin effect and kindred effect of winding all become more significantly, and resistance value will increase.In embodiment provided by the present invention,
The transformer harmonic impedance model proposed using IEEE：
ZT=h1.15RT+hXT (7)
In formula, ZTIt is main transformer Equivalent Harmonic impedance, RTAnd XTThe equivalent resistance of main transformer and reactance respectively under fundamental wave, h are humorous
Ripple number of times.
On high-voltage fence (system) and load, the power network scale of power system increasingly increases, but in frequency analysis, nothing
Whole system need to be calculated, node of concern need only be calculated, such as harmonic source is linked into the common node of system.If can be by these
The harmonic pollution level of common point is controlled within the range of permission, then harmonic pollution of the harmonic source to other points of whole system
All it is acceptable, it is therefore desirable to which equivalence is carried out to high-voltage fence.When the power of high-voltage fence or load is S, power factor is
During cos φ, the equivalent impedance of system or load under h subharmonic is：
In formula, Z is the harmonic wave equiva lent impedance of system or load, and R and X is respectively its fundamental wave equivalent resistance and reactance.
So far, the equivalent model of each element that harmonic propagation network is related to is set up and is completed, in each element equivalent model and
Harmonic flow calculation can be carried out on the basis of the follow-up harmonic propagation network equivalent model introduced.
S3, is equiva lent impedance structure by the thaumatropy of large-sized photovoltaic power station collector system, according to equiva lent impedance structure and
The equivalent model of each element that harmonic propagation network is related to is harmonic propagation network struction equivalent model, that is, obtain harmonic propagation net
Network bus admittance matrix.
It is equiva lent impedance structure by the collector system thaumatropy of large-sized photovoltaic power station, Fig. 6 and Fig. 7 is respectively large-scale grid-connected light
Overhead utility equiva lent impedance structure chart and current collection line equivalent impedance structure figure.Assuming that large-sized photovoltaic power station collector system by m bars simultaneously
Connection branch road composition, every branch road includes n generator unit altogether, as shown in Figure 6.Collector system generates electricity energy each generator unit
After collecting, through main transformer, ultra-high-tension power transmission line feeding power network, the equiva lent impedance structure chart of electric power transmission network is as shown in Figure 7.
Harmonic propagation network structure according to Fig. 6 and Fig. 7, obtains bus admittance matrix Y for (6mn+3) rank square formation.
K=6mn is made, is then had
In formula：Yai be (6n × 1) rank column vector, Yai=Ya, represent i-th collection electric line in each node with No. k+1
Transadmittance between node, Yk+i, k+i are the self-admittance (i=1,2) of k+i nodes in network；Yk+i, k+j are k+ in network
Transadmittance (i=1,2, j=1,2, and i ≠ j) between i nodes and k+j nodes.
Ym is the bus admittance matrix for collecting electric line wall scroll branch road, and Ym is (6n) rank square formation, and m Ym square is had in square formation Y
Battle array.
In formula (11), Y1, Y2 be 6 rank square formations, Y1 for collector system wall scroll branch road first generator unit and with its phase
The bus admittance matrix of cable even, Y2 is the node admittance of remaining each generator unit of this branch road and coupled cable
Matrix.To ensure the correctness of Ym, Yc is the supplement matrix of Yb.Y1, Y2, Yc can be tried to achieve by formula (12)-(14).
Wherein, ZL1 is the harmonic impedance of inductance 1, and ZL2 is the harmonic impedance of inductance 2；Zc is the harmonic impedance of electric capacity；Zt1
With the equiva lent impedance of the double transformer with split windings of Zt2；ZdiAnd Ydi(i=1,2 ... n) is respectively i-th list that generates electricity of wall scroll collection electric line
The equiva lent impedance of the latter linked cable run of unit and admittance.Square formation Y2 except outside Y2 (6,6), the value of remaining position with Y1 phases
Together, i-th of collector system wall scroll branch road (i=2,3 ..., n) Y2 (6,6) of the bus admittance matrix Y2 of generator unit be
Yc is (6n) rank symmetry square matrix, is had：
It should be noted that formula (12)-unaccounted parts of (14) matrix Y1, Y2, Yc are 0.
It is harmonic propagation network struction equivalent model, after obtaining harmonic propagation network node admittance matrix, according to each humorous
The harmonic electric current of wave source node and the harmonic propagation network node admittance matrix can obtain each node harmonic voltage, that is, obtain
Obtain harmonic trend.Multiplication factor of each node each harmonic voltage relative to the fundamental voltage can also be obtained.By right
Harmonic trend and each node each harmonic voltage are analyzed research, Ke Yijin relative to the multiplication factor of the fundamental voltage
One step realizes research to harmonic problem, and takes and effectively guard against remedial measure.Below to current collection system in large-sized photovoltaic power station
The cable data of collector system is joined to frequency analysis result, the parameter of LCL filter to harmonic flow calculation result, cable in system
Several influences to harmonic flow calculation result are illustrated by experiment respectively.
Before being illustrated by experiment, first the Load flow calculation formula used in experiment is simply introduced.With
Fundamental load flow calculates similar, and harmonic flow calculation is exactly the harmonic electric current and the harmonic propagation net according to each harmonic wave source node
The network equation of network bus admittance matrix composition solves each node harmonic voltage, i.e.,
U (h)=Y-1(h)I(h) (2)
In formula：U (h) is each node h subharmonic voltage column vectors；Y (h) is the node admittance square that h subharmonic transmits network
Battle array；I (h) is each node h subharmonic Injection Current column vector.Harmonic source condition of work is pressed, according to fundamental wave result of calculation, harmonic wave
The Injection Current of corresponding each harmonic is counted and calculated, Injection Current vector I (h) is formed.In implementation provided by the present invention
In example, node Injection Current of the order containing harmonic source is unit h subharmonic currents, and the node Injection Current without harmonic source is 0.
It should be noted that the size of each element equivalent impedance becomes with the change of overtone order in harmonic propagation network
Change, therefore need repeatedly to form harmonic propagation network node admittance matrix in the calculation.
In the collector system of large-sized photovoltaic power station, the cable between each generator unit is because line length is short, voltage class
It is low, thus the influence of cable data is have ignored in some studies, it is believed that each generator unit is simple parallel relationship, is such as schemed
Shown in 8.
After harmonic propagation network is established, by carrying out harmonic flow calculation, each node in network can be obtained
Magnitude of voltage under each harmonic.With each harmonic voltage magnitude of certain point divided by the point fundamental voltage amplitude, it is possible to
Obtain under each harmonic, the multiplication factor of the harmonic voltage relative to fundamental voltage of the point.Due in harmonic propagation network
Node is more, in the present invention, only chooses main transformer low side node, i.e., the points of common connection (point of each generator unit
Of common coupling, PCC) it is analyzed as representative.Each component parameters is as shown in table 1 in network.
Each component parameters displaying table in the transmission network of table 1
It is computed, the amplification situation of PCC points harmonic voltage is as shown in Figure 9 under 2 kinds of structures.It can be seen in figure 9 that neglecting
In slightly standing after the cable data of collector system, the resonant frequency of network decreases, and the voltage amplification factor of resonance point is also obvious
Increase, the voltage amplification situation of remaining each point is also changed.
The voltage amplification factor of PCC points each harmonic is as shown in table 2 under 2 kinds of structures.
The PCC point each harmonics voltage amplification factor of table 2 shows table
Data can be seen that and consider that in station in the case of collector system cable data, the network is in input 7 from table 2
Resonance is there occurs during subharmonic current, when overtone order is less than 7 times, voltage amplification factor is in the increase of input harmonics number of times
Ascendant trend, is then gradually reduced, and when overtone order is more than after 35 times, harmonic voltage is less than fundamental voltage；Ignoring in station
In the case of collector system cable data, network there occurs resonance when 6 subharmonic current is input into, when overtone order is less than 6 times
When, voltage amplification factor is in rising trend with the increase of input harmonics number of times, is then gradually reduced, when overtone order is more than 28 times
Afterwards, the variation tendency of voltage amplification factor does not have obvious corresponding relation with overtone order, but under this structure, no matter to network
Several subharmonic currents are injected, the harmonic voltage amplitude of PCC points is consistently greater than fundamental voltage amplitude.
As can be seen here, the cable data of collector system can cause one to be fixed to frequency analysis result in large-sized photovoltaic power station
Ring, so being contemplated that the cable data of collector system in station when frequency analysis is carried out.
Influence of the parameter on LCL filter to harmonic flow calculation result, it is considered to collector system cable data in standing
Situation, on the basis of the given parameters of table 1, individually adjustment LCL filter parameter L1, L2 and C value after, each time of PCC points
The amplification situation of harmonic voltage is as shown in Figure 10-12.
As Figure 10-12 as can be seen that the change in L1 scopes shown in Figure 10 is not to PCC point each harmonic voltages
Multiplication factor produces obvious influence, but is not excluded for producing other node harmonic voltages in network the possibility of influence；With L2
The increase of value, the resonant frequency of PCC points is gradually reduced, and resonant frequency is below 11 times, the voltage amplification factor of resonance point
More than 200 times；Influences of the electric capacity C to each harmonic voltage amplification situation of PCC points is similar with L2, with the increase of C values,
The resonant frequency of PCC point voltages is gradually reduced, and resonant frequency is below 25 times.But compared with L2, the change of C values is easier
Cause PCC points that resonance occurs.
Influence on cable data to harmonic flow calculation result, it is considered to the situation of collector system cable data in standing,
On the basis of the given parameters of table 1, individually after the value of impedance and the admittance of adjustment unit length cable, PCC points each harmonic electricity
The amplification situation of pressure is as shown in Figure 13-14.
By Figure 13-14 as can be seen that the change of cable resistance value size does not almost have shadow to the resonant frequency of PCC points
Ring, but with the increase of cable resistance value, PCC points voltage amplification factor at the resonant frequency fx first reduces and increases afterwards；Cable
The change of admittance value size does not also influence significantly on the resonant frequency at PCC points, but with the increase of cable admittance value,
PCC points voltage amplification factor at the resonant frequency fx gradually increases, but the comparing of increase is slow.
Due in station in collector system, cable run length between each generator unit is short, voltage class is low, so electric
The change of cable parameter is not obvious for the influence of PCC point each harmonic voltage amplification factors, but if not considering voltage amplification
Multiple, only from the point of view of the result of calculation of voltage magnitude, the shadow of the change of cable data to this each harmonic voltage magnitude size
Sound is more obvious.Thus can also illustrate, when frequency analysis is carried out to large-sized photovoltaic power station, be contemplated that cable data for
The influence of analysis result.
For typical large-scale grid-connected photovoltaic power station topological structure, establish and consider the large-scale of the interior collector system structure in station in detail
Photovoltaic plant harmonic propagation network model is very necessary.By experimental data, draw to draw a conclusion.
(1) whether photovoltaic plant inside collector system structure is considered, the harmonic voltage amplification characteristic of PCC points is in the presence of substantially poor
Not.
(2) the LCL filter parameter of photovoltaic DC-to-AC converter has an impact to PCC point harmonic voltage amplification characteristics, wherein L2 and C values
Change influenceed more substantially for harmonic voltage amplification characteristic, the influence of the change of L1 to PCC points is not obvious, but is not excluded for
It exists on power station internal node influences.
(3) collector system inside cable line parameter circuit value has an impact to PCC point harmonic voltage amplification characteristics.Generate electricity single due to each
Cable run length between unit is short, voltage class is low, the harmonic voltage amplification characteristic shadow of the change for the point of cable data
Sound is relatively small.
Based on above-mentioned experimental result, illustrate considering in detail in station on the basis of collector system structure, to large-sized photovoltaic electricity
Harmonic propagation network in Mechatronic Systems of standing is modeled very necessary.
In sum, in the collector system of large-sized photovoltaic power station provided by the present invention harmonic propagation network modeling method,
By determining to be used to set up model the need for harmonic propagation network is related in the large-sized photovoltaic power station collector system of home energy source
Each element；For each element in the harmonic propagation network of determination sets up equivalent model；Then, by large-sized photovoltaic power station collector system
Thaumatropy is equiva lent impedance structure, and the equivalent model according to equiva lent impedance structure and each element is harmonic propagation network struction
Equivalent model, that is, obtain harmonic propagation network node admittance matrix.The method takes into full account collector system in large-sized photovoltaic power station
Influence, the parameter of LCL filter of the cable data of middle collector system to frequency analysis result are to harmonic flow calculation result
The influence of influence and cable data to harmonic flow calculation result, improves the authenticity of harmonic propagation network modelling.For rear
The accuracy of continuous harmonic flow calculation provides good basis.
The modeling method to harmonic propagation network in the collector system of large-sized photovoltaic power station provided by the present invention is carried out above
Detailed description.For those of ordinary skill in the art, to its institute on the premise of without departing substantially from true spirit
Any obvious change done, will all be constituted to infringement of patent right of the present invention, will undertake corresponding legal liabilities.
Claims (9)
1. in a kind of collector system of large-sized photovoltaic power station harmonic propagation network modeling method, it is characterised in that including following step
Suddenly：
S1, determines each element for setting up equivalent model that harmonic propagation network is related in the collector system of large-sized photovoltaic power station；
S2, for the described each element for determining sets up equivalent model；
S3, is equiva lent impedance structure by the thaumatropy of large-sized photovoltaic power station collector system, according to the equiva lent impedance structure and
The equivalent model of each element is harmonic propagation network struction equivalent model, that is, obtain harmonic propagation network node admittance square
Battle array.
2. in the collector system of large-sized photovoltaic power station as claimed in claim 1 harmonic propagation network modeling method, its feature exists
In：
In step sl, each element for setting up model includes：Element, transmission line of electricity and the electricity included in photovoltaic generation unit
Cable, main transformer, high-voltage fence and load.
3. in the collector system of large-sized photovoltaic power station as claimed in claim 2 harmonic propagation network modeling method, its feature exists
In：
The element included in the photovoltaic generation unit is photovoltaic DC-to-AC converter LCL filter and double transformer with split windings；
Wherein, the harmonic impedance of the photovoltaic DC-to-AC converter LCL filter is represented with equation below：
Wherein, ZLIt is the harmonic impedance of inductance；XLIt is the fundamental reactance of inductance；H is overtone order；ZcIt is the harmonic impedance of electric capacity；
XcIt is the fundamental reactance of electric capacity, j is conversion coefficient.
4. in the collector system of large-sized photovoltaic power station as claimed in claim 3 harmonic propagation network modeling method, its feature exists
In：
The equiva lent impedance of described pair of transformer with split winding is represented with equation below：
Wherein, Xt1It is the fundamental wave equivalent reactance of double transformer with split winding primary side windings；Xt2、Xt3Respectively two bases of vice-side winding
Ripple equivalent reactance, h is overtone order.
5. in the collector system of large-sized photovoltaic power station as claimed in claim 2 harmonic propagation network modeling method, its feature exists
In：
The main transformer harmonic impedance model is：
ZT=h1.15RT+hXT
Wherein, ZTIt is main transformer Equivalent Harmonic impedance, RTAnd XTThe equivalent resistance of main transformer and reactance respectively under fundamental wave, h are harmonic wave
Number.
6. in the collector system of large-sized photovoltaic power station as claimed in claim 2 harmonic propagation network modeling method, its feature exists
In：
Equivalent impedance of the high-voltage fence with load under h subharmonic be：
Wherein, Z is the harmonic wave equiva lent impedance of system or load, and R and X is respectively its fundamental wave equivalent resistance and reactance.
7. in the collector system of large-sized photovoltaic power station as claimed in claim 1 harmonic propagation network modeling method, its feature exists
In：
In step s 2, it is that harmonic propagation network struction equivalent model is, according to harmonic propagation network structure, to obtain node admittance
Matrix Y；
Wherein, Y is (6mn+3) rank square formation, makes k=6mn, then have：
In formula, Ya=Yai, the transadmittance in i-th collection electric line of expression between each node and k+1 nodes, Yk+i, k+i
It is the self-admittance (i=1,2) of k+i nodes in network；Yk+i, k+j be network between k+i nodes and k+j nodes
Transadmittance (i=1,2, j=1,2, and i ≠ j), Ym is the bus admittance matrix for collecting electric line wall scroll branch road, and Ym is (6n) rank side
Battle array, has m Ym matrix in square formation Y.
8. in the collector system of large-sized photovoltaic power station as claimed in claim 7 harmonic propagation network modeling method, its feature exists
In：
Ya is (6n × 1) rank column vector, and Ya is represented with equation below：
9. in the collector system of large-sized photovoltaic power station as claimed in claim 7 harmonic propagation network modeling method, its feature exists
In：
Ym is the bus admittance matrix for collecting electric line wall scroll branch road, and Ym is represented with equation below：
Wherein, Y1, Y2 are 6 rank square formations, and Y1 is first generator unit and coupled cable of collector system wall scroll branch road
Bus admittance matrix, Y2 is the bus admittance matrix of remaining each generator unit of this branch road and coupled cable, Yc
It is the supplement matrix of the matrix of Y1, Y2 composition.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611074065.6A CN106786731A (en) | 2016-11-29 | 2016-11-29 | The modeling method of harmonic propagation network in a kind of collector system of large-sized photovoltaic power station |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611074065.6A CN106786731A (en) | 2016-11-29 | 2016-11-29 | The modeling method of harmonic propagation network in a kind of collector system of large-sized photovoltaic power station |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN106786731A true CN106786731A (en) | 2017-05-31 |
Family
ID=58898523
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201611074065.6A Pending CN106786731A (en) | 2016-11-29 | 2016-11-29 | The modeling method of harmonic propagation network in a kind of collector system of large-sized photovoltaic power station |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106786731A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109116183A (en) * | 2018-06-28 | 2019-01-01 | 全球能源互联网研究院有限公司 | Harmonic-model parameter identification method, device, storage medium and electronic equipment |
| CN109617053A (en) * | 2018-12-10 | 2019-04-12 | 国网河南省电力公司电力科学研究院 | A kind of electric line higher hamonic wave propagation coefficient method for testing and analyzing and device |
| CN112444675A (en) * | 2020-12-14 | 2021-03-05 | 南方电网科学研究院有限责任公司 | Harmonic superstandard early warning method, device, equipment and medium for power transmission network nodes |
| CN112615378A (en) * | 2020-12-08 | 2021-04-06 | 深圳供电局有限公司 | Distribution network high-frequency resonance frequency shift method and device and computer readable storage medium |
| CN117650521A (en) * | 2023-11-30 | 2024-03-05 | 深圳南控新能源有限公司 | Modeling method for harmonic interaction influence analysis model of photovoltaic power station and power distribution network |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0715879A (en) * | 1993-06-28 | 1995-01-17 | Sansha Electric Mfg Co Ltd | Generator system |
| CN103544378A (en) * | 2013-09-28 | 2014-01-29 | 南方电网科学研究院有限责任公司 | Method for calculating harmonic impedance of alternating current system for direct current transmission |
| CN103701152A (en) * | 2014-01-15 | 2014-04-02 | 国家电网公司 | Method and system for obtaining flicker transmission coefficient of grid connection of photovoltaic power stations |
-
2016
- 2016-11-29 CN CN201611074065.6A patent/CN106786731A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0715879A (en) * | 1993-06-28 | 1995-01-17 | Sansha Electric Mfg Co Ltd | Generator system |
| CN103544378A (en) * | 2013-09-28 | 2014-01-29 | 南方电网科学研究院有限责任公司 | Method for calculating harmonic impedance of alternating current system for direct current transmission |
| CN103701152A (en) * | 2014-01-15 | 2014-04-02 | 国家电网公司 | Method and system for obtaining flicker transmission coefficient of grid connection of photovoltaic power stations |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109116183A (en) * | 2018-06-28 | 2019-01-01 | 全球能源互联网研究院有限公司 | Harmonic-model parameter identification method, device, storage medium and electronic equipment |
| CN109116183B (en) * | 2018-06-28 | 2020-07-31 | 全球能源互联网研究院有限公司 | Harmonic model parameter identification method and device, storage medium and electronic equipment |
| CN109617053A (en) * | 2018-12-10 | 2019-04-12 | 国网河南省电力公司电力科学研究院 | A kind of electric line higher hamonic wave propagation coefficient method for testing and analyzing and device |
| CN112615378A (en) * | 2020-12-08 | 2021-04-06 | 深圳供电局有限公司 | Distribution network high-frequency resonance frequency shift method and device and computer readable storage medium |
| CN112444675A (en) * | 2020-12-14 | 2021-03-05 | 南方电网科学研究院有限责任公司 | Harmonic superstandard early warning method, device, equipment and medium for power transmission network nodes |
| CN117650521A (en) * | 2023-11-30 | 2024-03-05 | 深圳南控新能源有限公司 | Modeling method for harmonic interaction influence analysis model of photovoltaic power station and power distribution network |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106849093A (en) | For the large-sized photovoltaic power station collector system harmonic flow calculation method of home energy source | |
| CN106786731A (en) | The modeling method of harmonic propagation network in a kind of collector system of large-sized photovoltaic power station | |
| CN103107559B (en) | A kind of method determining Distributed Power Flow controller system parameter | |
| CN104810857B (en) | Single-phase grid-connected photovoltaic power generation system output power smooth control device and control method | |
| CN103310121B (en) | A kind of large-sized photovoltaic power station and distribution interaction of harmonics analytical model modeling method | |
| CN104638678A (en) | Multi-fan grid-connected resonance analysis method | |
| CN105226668A (en) | A kind of addressing for UPFC and capacity collocation method | |
| CN106655195B (en) | Active power distribution network high-frequency harmonic power flow calculation method | |
| CN103236800A (en) | Novel topological structure voltage source type inverter and adjusting method | |
| CN111509987A (en) | Resonant converter, parameter optimization method and device thereof, and electronic equipment | |
| CN103248044A (en) | Load flow calculation method and system for power distribution network | |
| CN106295231A (en) | A kind of marine wind electric field resonance suppressing method based on modal calculation | |
| CN106357119B (en) | High-power high voltage photovoltaic DC booster converter device and control method | |
| CN111291468B (en) | Flexible substation modeling method for efficient electromagnetic transient simulation | |
| CN103248210B (en) | A kind of power synchronous control method for reducing the fluctuation of DC voltage secondary | |
| Wu et al. | Equivalent modeling of photovoltaic power station based on canopy-FCM clustering algorithm | |
| CN109861229B (en) | AC-DC hybrid system stability analysis method and system based on hybrid potential function | |
| CN106452098A (en) | High-voltage and large-power wind power generation system and control method thereof | |
| CN107046287A (en) | A kind of large-sized photovoltaic power station harmonic wave Over-voltage Analysis method | |
| CN106849154B (en) | Photovoltaic power station node harmonic voltage and harmonic source sensitivity relation analysis method | |
| CN112968470A (en) | Topological optimization method for offshore wind farm current collection system avoiding resonance region | |
| CN107677943A (en) | A kind of High Voltage XLPE Power Cable and its annex fundamental wave superposition multiple-harmonic experimental rig | |
| CN103812139A (en) | Power distribution network system based on single-conductor alternating current and direct current hybrid technology | |
| CN106655174A (en) | Comprehensive reconstruction optimization method for power distribution network | |
| CN102142685B (en) | Software design method for inductor-capacitor-inductor (LCL) filter on network side of directly-driven wind power generation converter |
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 | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20170531 |