CN107681682A - A kind of ac and dc systemses equivalence method equivalent based on WARD - Google Patents
A kind of ac and dc systemses equivalence method equivalent based on WARD Download PDFInfo
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- CN107681682A CN107681682A CN201711009021.XA CN201711009021A CN107681682A CN 107681682 A CN107681682 A CN 107681682A CN 201711009021 A CN201711009021 A CN 201711009021A CN 107681682 A CN107681682 A CN 107681682A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- 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]
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- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]
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Abstract
The present invention relates to a kind of ac and dc systemses equivalence method equivalent based on WARD, its step：Each primary element model is established, obtains data based on the whole network node, and determine data format；Load flow calculation is carried out to the whole network, obtains the whole network flow solution；It is internal node set, boundary node set and external node set by node division, each interior element of gathering arranges from small to large according to node serial number；Form the bus admittance matrix of whole network, according to the node set of division, formed equivalent calculation blocking node admittance matrix；The equivalent injecting powers of value matrix and border equivalent capacitance and border such as calculating；New structured data body is formed, and preserves the basic data of system after equivalence, is defined as Rempc；Load flow calculation is carried out to system after equivalence, the equivalent front and rear power flow solutions for retaining branch road and node is contrasted, selectively exports power flow solutions.The trend error very little of reservation system before and after equivalence can be effectively ensured in the present invention, can be extended in extra-high voltage direct-current hierarchical system.
Description
Technical field
The present invention relates to a kind of power system extra-high voltage alternating current-direct current equivalent calculation field, and WARD is based on especially with regard to one kind
Equivalent ac and dc systemses equivalence method.
Background technology
With the construction of extra-high voltage direct-current engineering, direct current transmission capacity is continuously increased, and direct current drop point is increasingly concentrated, existing
Some direct current individual layer access ways will be unfavorable for the trend evacuation, the receiving ability of system receiving end, voltage support etc. of receiving-end system
Aspect will produce a series of problems.Because under extra-high voltage direct-current layer-specific access mode, the topological structure of straight-flow system is more multiple
Miscellaneous, the reciprocal effect between ac and dc systemses, between two layers of receiving end, which also turns into, needs that pays close attention to study a question.In order to which accurate simulation contains
The friendship of transient characterisitics or progress layer-specific access DC engineering of the alternating current-direct current bulk power grid of layer-specific access during unbalanced fault
Wave filter design is flowed, generally requires and ultra-large power network is carried out to simplify equivalence, to provide calculating speed and simulation efficiency.So
Layer-specific access extra-high voltage direct-current is exchanged bring many benefits to us while, the problem of inevitably also band is new and is chosen
War.The transmission of electricity advantage of extra-high voltage direct-current layer-specific access AC system is played, solves the key technology faced under this voltage class
Problem.This realizes high-power long distance power transmission, the interconnection of remote distance power system, and then realize to further improving ability to transmit electricity
Big regional power grid interconnection is significant.
The content of the invention
In view of the above-mentioned problems, it is an object of the invention to provide a kind of ac and dc systemses equivalence method equivalent based on WARD,
It can design for extra-high voltage alternating current-direct current power transmission engineering and provide foundation.
To achieve the above object, the present invention takes following technical scheme：A kind of ac and dc systemses equivalent based on WARD etc.
Value method, it is characterised in that comprise the following steps：1) each primary element model in WARD Equivalent Models is established, from each primary element
Data based on acquisition the whole network node in model, and determine that data format is Matpower standard data formats or BPA numbers
According to form, if BPA data formats, then convert thereof into Matpower reference formats and calculated；2) tide is carried out to the whole network
Stream calculation, the whole network flow solution is obtained, power flow solutions are defined in an entitled result structure, form and data structure
Body is similar；3) it is internal node set I, boundary node set B and external node set E by node division, member in each set
Element arranges from small to large according to node serial number；4) node admittance subfunction makeYbus is called to form the node admittance of whole network
Matrix, according to the node set of division, formed equivalent calculation blocking node admittance matrix；5) calculating matrix YEQAnd border
Equivalent capacitance C obtains the equivalent branch parameters in border after equivalence, thus calculates the equivalent injecting power S in borderEQ=Pi EQ+jQi EQ；6)
New structured data body is formed, and preserves the basic data of system after equivalence, is defined as Rempc, step 5) is tied added to new
In structure data volume；7) Load flow calculation is carried out to system after equivalence, contrasts the equivalent front and rear power flow solutions for retaining branch road and node, have
Selectively power flow solutions are exported.
Further, in the step 1), primary element model includes circuit model, generator and load model, member in parallel
Part model, Asymmetric Links model, transformer branch and border electric capacity.
Further, in the step 2), it is substantially square including node power equation, transverter that Load flow calculation is carried out to the whole network
Journey, DC network equation and governing equation.
Further, the node power equation：
Wherein, i=na+ k, k=1,2 ..., nc, positive sign represents inverter in formula, and negative sign represents rectifier.With AC system
Network equation contrasts, and adds Vdk, IdkWithThree variables, they represent DC node voltage, Injection Current and electricity respectively
Angle between current voltage is the power-factor angle of transverter.ΔPiRepresent to give active amount of unbalance；ΔQiRepresent given nothing
Work(amount of unbalance；PisRepresent given active power；QisRepresent given reactive power；ViRepresent the voltage of node i；VjRepresent
Node j voltage；θijRepresent the phase angle difference between node i and node j；GijRepresent the real part of admittance matrix；BijRepresent admittance square
The imaginary part of battle array.
Further, the transverter fundamental equation, for transverter k, there is equation below：
Wherein, Δ d1k、Δd2kRepresent DC voltage amount of unbalance；VdkTransverter DC voltage is represented,Represent the change of current
Transformer alternating side line voltage perunit value, IdkRepresent the DC current of transverter；XckConverter power transformer k equivalent impedance is represented,
kTkRepresent the no-load voltage ratio of converter power transformer, kγFor close to 1 constant, θdkTransverter k pilot angles are represented,Represent the work(of transverter
Rate factor angle.
Further, the canonical form of the DC network equation：
Wherein, Δ d3kRepresent the amount of unbalance of transverter output DC current, IdkRepresent transverter k DC current；Vdj
Represent the DC voltage of j-th of DC node, gdkjRepresent the nodal-admittance matrix member of the DC network after cancellation contact node
Element, voltage x current represents the voltage and current of DC line in formula.For a simple two-terminal direct current transmission system, direct current
Network equation is simplified as：
It is as follows for a simple two-terminal direct current transmission system, DC network equation simplification：
In formula, R represents the resistance of DC line；Id1Represent the electric current of 1 end DC node；Id2Represent 2 end DC nodes
Electric current；If the resistance of DC line is sufficiently small, V can be approximately consideredd1=Vd2, Id1=Id2。
Further, the governing equation：
Δd4k=d4k(Idk,Vdk,cosθdk,kTk)=0 (k=1,2 ..., nc)
Δd5k=d5k(Idk,Vdk,cosθdk,kTk)=0 (k=1,2 ..., nc)
In formula, d4kRepresent the function of rectifier no-load voltage ratio and current imbalance amount, Δ d4kRepresent rectifier control variable not
Aequum, d5kRepresent inverter no-load voltage ratio and the function of pilot angle amount of unbalance, Δ d5kRepresent the imbalance of inverter control variable
Amount, IdkRepresent transverter k DC current；VdkRepresent transverter k DC voltages；θdkRepresent transverter k pilot angles；kTkRepresent
The no-load voltage ratio of converter power transformer；Due to observing variable relevant with pilot angle in all formulas with cos θdkForm occur, to carry
The linearity of high equation, with cos θdkFor amount directly to be asked.
Further, in the step 3), need to possess two kinds of fault-tolerant abilitys：Determine not hand between set I, B and E first
Collection, and the number of set I, B and E union is equal to total nodes；Secondly whether balance nodes are included in detection set I, such as
Fruit does not include, then using balance nodes as boundary node force retain, into next step, if be directly entered comprising if in next step.
Further, in the step 5), border equivalent capacity C is：
Pure routine calculation method：
C (k)=C (k)+ykj
In formula, k ∈ i；
Transformer lines computational methods, and boundary node is first node：
Transformer lines computational methods, and boundary node is end-node：
Wherein, Yij(i ≠ j) represents the negative value of the line admittance of node i and node j composition branch roads, the related ginseng of the branch road
Number is expressed as：Line admittance yij, the total admittance b over the ground of circuitij, transformer voltage ratio τij, phase shift θij。
Further, in the step 6), the principle of node definition is suitable according to internal node set and boundary node set
Sequence is arranged, alternator data and branch data in reservation system, and new alternator data and branch data are needed according to again
The node serial number of arrangement makes corresponding change；Then, increased equivalent virtual tributary and border capacitance data are added respectively
Into the branch road and node data of new data.
For the present invention due to taking above technical scheme, it has advantages below：1st, the present invention take into account WARD equivalent methods
Otherness between improved WARD equivalent methods, both comprising conventional WARD equivalent methods it is simple and practical the characteristics of, taken into account again each
Improved WARD methods carry out the advantages of equivalent.2nd, the present invention is asked the details in the basic model and equivalence course of Static Equivalent
Topic has carried out labor, including the processing of border electric capacity and the selection of equivalent branch model.It is proposed that node divides group, i.e., when flat
The node that weighs is forced to retain not when retaining internal system using balance nodes as boundary node.3rd, the present invention is based on conventional WARD etc.
Value method develops the equivalent instrument of bulk power grid Ac/dc Power Systems, provides equivalent instrument and applies in different alternating current and direct current systems
Sample calculation analysis, illustrate the trend error very little of reservation system before and after equivalence.4th, the present invention establishes whole system according to node-classification
The network equation of system, wherein Y matrixes are the bus admittance matrixs of whole network, and Y matrixes are arranged again according to node division result
Row, form corresponding blocking node admittance matrix.Introduced after equivalence in admittance matrix by external node and boundary node shape
Into Equivalent admittance matrix YEQ, and the part of other changes only has the Injection Current I of original system boundary nodeB, internal node do not have
Change.For a linear system, this process by be rigorous equivalence process, as long as the Injection Current of external network
IEDo not change, then under any method of operation, waiting the trend of valve system should be consistent with former network.5th, when increasing in system
The model of DC line is added, the present invention just needs to increase corresponding direct current net in the trend timing for calculating Ac/dc Power Systems
Network equation.The structure of straight-flow system can not use the method for AC system Load flow calculation directly count with exchanging that difference is very big
Calculate Ac/dc Power Systems.Analyzed from the model of DC line, the network equation of Ac/dc Power Systems is mainly from four
Aspect makes corresponding modification：Node power equation, transverter fundamental equation, DC network equation and governing equation.6th, pass
For the method for the power network Static Equivalent of system both for AC system, equivalent essence is to network equation abbreviation, eliminates outside segments
The influence of point.But for Ac/dc Power Systems, the network equation of system because containing direct current and there occurs very big
Change, can not form unified bus admittance matrix, and method equivalent conventional WARD can not be also applicable.Therefore, the present invention uses
Equivalent branching and equivalent power method are handled DC line, convert it into the mould that AC system equivalence can be handled
Type, equivalent calculation is then carried out again.7th, the present invention have studied DC power transmission system on the basis of AC system static equivalence method
System model, according to alternating current-direct current calculation of tidal current, establishes alternating current-direct current equivalent model, and equivalent research is carried out to ac and dc systemses,
The alternating current-direct current equivalent model that present invention proposes can be extended in extra-high voltage direct-current hierarchical system.
Brief description of the drawings
Fig. 1 is the WARD equivalence schematic flow sheets of the present invention；
Fig. 2 is the transformer lines model schematic that the present invention uses；
Fig. 3 is the non-symmetrical line model schematic that the present invention uses；
Fig. 4 is model schematic after the non-symmetrical line processing that the present invention uses；
Fig. 5 is the transformer π type equivalence branch road schematic diagrames that the present invention uses；
Fig. 6 is the compensating electric capacity Equivalent Model schematic diagram that the present invention uses；
Fig. 7 is that the present invention retains balance nodes and divides group's processing structure figure；
Fig. 8 is the direct current transportation general principle wiring diagram that the present invention uses；
Fig. 9 is the equivalent π types line map of equivalent branching that the present invention uses；
Figure 10 is the equivalent branching equivalent symmetrical π type line maps that the present invention uses；
Figure 11 is DC line equivalent power method schematic diagram of the present invention；
Figure 12 a are that the present invention applies to trend Error Graph before the node system equivalences of IEEE 30；
Figure 12 b are that the present invention applies to trend Error Graph after the node system equivalences of IEEE 30；
Figure 13 a be the present invention apply to after the node systems of the IEEE 30 change method of operation to have before equivalence, reactive power error figure；
Figure 13 b be the present invention apply to after the node systems of the IEEE 30 change method of operation to have after equivalence, reactive power error figure；
Figure 14 is the CEPRI-36 system topology figures in present example；
Figure 15 a are the active power flow error comparison diagrams that the present invention applies to equivalent branching CEPRI-36 systems；
Figure 15 b are the reactive power trend error comparison diagrams that the present invention applies to equivalent branching CEPRI-36 systems；
Figure 16 a are the active power flow error comparison diagrams that the present invention applies to equivalent power method CEPRI-36 systems；
Figure 16 b are the reactive power trend error comparison diagrams that the present invention applies to equivalent power method CEPRI-36 systems.
Embodiment
The present invention is described in detail with reference to the accompanying drawings and examples.It should be appreciated, however, that the offer of accompanying drawing is only
For a better understanding of the present invention, they should not be interpreted as limitation of the present invention.
As shown in figure 1, the present invention provides a kind of ac and dc systemses equivalence method equivalent based on WARD, it includes following step
Suddenly：
1) each primary element model in WARD Equivalent Models is established, the whole network node conduct is obtained from each primary element model
Basic data, and determine that data format is Matpower standard data formats or BPA data formats, if BPA data lattice
Formula, then convert thereof into Matpower reference formats and calculated.Basic data is defined as structure mpc；Wherein
Mpc.bus, mpc.branch, mpc.gen and mpc.baseMVA represent node data respectively, branch data, alternator data and
Reference power；
Each primary element model includes circuit model, generator and load model, parallel element model, Asymmetric Links mould
Type, transformer branch and border electric capacity；Also include the DC Model introduced by Ac/dc Power Systems.
When carrying out Static Equivalent analysis, accurate component models are the passes for ensureing to obtain accurate reliable calculation of tidal current
Key factor.During WARD Equivalent Models are studied, with reference to various typical primary element models, each base that the present invention establishes
This component models is as follows：
1.1) establish circuit model：
As shown in Fig. 2 in Practical Project, circuit model uses the π molded line road of standard, line admittance ys=1/ (rs+
jxs), wherein, rsRepresent line resistance, xsRepresent line reactance；Total charging capacitor bcRepresent, by standard circuit model string
It is exactly the circuit model containing transformer to join a transformer, ignores the excitation impedance of transformer.The position of transformer is in every line
The head end on road, non-standard no-load voltage ratio represent that the angle of phase displacement of transformer is θ with τshift, ifAnd itThe electricity at circuit first and last end is represented respectively
Stream, vfAnd vtThe voltage at circuit first and last end is represented respectively, and the positive direction of electric current is identical with the direction of arrow in Fig. 2.According to Fig. 2
Circuit model, the nodal voltage equation that can obtain the circuit is as follows：
Wherein：
1.2) generator and load model are established：
Due to not being related to transient state and the process of optimal load flow during Static Equivalent, generator and load model can be set
Put fairly simple, be accordingly to be regarded as complex power injection that some presets node.For generator node, injecting powerCan be with table
It is shown as：
In formula,Represent generator node injection active power.Generator node injection reactive power is represented, i is represented
Node serial number (similarly hereinafter).
For the load power of node iFor：
In formula,Represent load active power；Represent reactive load power.
1.3) parallel element model is established：
Generally need to carry out the electric capacity or inductance element of certain reactive-load compensation, these electric capacity or electricity on high-tension line
Sense is referred to as parallel element.Parallel element model definition is a constant impedance model for being connected in parallel on node side, and with admittance
Form provides.The parallel element admittance of node is defined as：
In formula,Represent parallel element admittance；Represent parallel element conductance；Represent parallel element susceptance.
Shunt capacitance injects capacitive reactive power to system, plays the effect for maintaining node voltage constant.Shunt inductance is to system
Inductive reactive power is injected, can suppress that node voltage is too high, so the data of parallel element are typically to be write in the form of power.
And the injection that the change of node voltage can change parallel element is idle, so the data of the part are with respective nodes voltage perunit
Be worth for 1.0 when, the form write-in data file for the power that element in parallel injects to system, corresponding unit is MW and MVAR.
It is actually implanted into idle, is changed accordingly according to actual voltage value.
1.4) to the processing of Asymmetric Links model
Generally, the model of non-symmetrical line is as shown in Figure 3.Wherein C1And C2Expression is connected in parallel on the electric capacity of circuit the right and left,
General C1And C2Value be two equal positive numbers or one positive one negative, work as C1Or C2When being worth to bear, parallel connection inductance is represented.
It is equal on the occasion of being handled as π molded line road, processing method is identical with general circuit for two.For one
In the case that positive one is negative, the processing method that the present invention uses is to convert thereof into two parts consideration, i.e., symmetrical π molded line road and parallel connection
Inductance, so non-symmetrical line is respectively added in line parameter circuit value and node parameter.Model after conversion as shown in figure 4,
Wherein, WithThe capacitive reactance of Asymmetric Links the right and left is represented respectively；XLRepresent non-symmetrical line etc.
Parallel reactance after effect.
1.5) transformer branch is handled
The accurate equivalent branch road of transformer is an equivalent branch road of T-shaped, and it can reflect transformer station high-voltage side bus exactly
Real conditions, but the equivalent branch road of T-shaped contains series-parallel form, is inconvenient when analyzing power system.Consider
To transformer in normal operation, excitation impedance is bigger, generally shifts to an earlier date excitation impedance branch road, therefore has reformed into Γ types etc.
Imitate branch road.The establishment of transformer model is particularly significant, and the idle degree of accuracy especially on system influences very big.Transformer branch is done
π types convert, as shown in figure 5, the influence of the non-standard no-load voltage ratio of transformer is thus have ignored, then the method with processing non-symmetrical line
Changed into Matpower basic datas.The problem of using need not just consider further that no-load voltage ratio direction after π type equivalent circuits.
1.6) processing of border electric capacity
As shown in fig. 6, virtual circuit is handled as real impedance circuit, then calculate in parallel at each boundary node
Compensating electric capacity.Boundary node represents that boundary node number is nb with set B；Internal node represents with set I, internal node
Number is represented with ni.Yij(i ≠ j) represents the negative value of the line admittance of node i and node j composition branch roads, the related ginseng of the branch road
Number is expressed as：Line admittance yij, the total admittance b over the ground of circuitij, transformer voltage ratio τij, phase shift θij.Define arrays C (i) (i=
1,2 ... nb) stored boundary node capacitor.Specific formula for calculation is as follows：
Pure routine calculation method：
C (k)=C (k)+ykj
In formula, k ∈ i；
Transformer lines computational methods, and boundary node is first node：
Transformer lines computational methods, and boundary node is end-node：
1.7) DC line model
One simple DC transmission system is handed over as shown in figure 8, when the model that DC line is added in system calculating
The trend timing of direct current hybrid system just needs to increase corresponding DC network equation.The structure of straight-flow system is with exchanging difference very
Greatly, therefore the method for AC system Load flow calculation can not be used directly to calculate Ac/dc Power Systems.From the model of DC line
Analyzed, the network equation of Ac/dc Power Systems is mainly made that corresponding modification in terms of four：Node power equation,
Transverter fundamental equation, DC network equation and governing equation.
2) Load flow calculation is carried out to the whole network, obtains the whole network flow solution.Power flow solutions are defined on one of entitled result
In structure, form is similar with data structure, convenient to call；
It is assumed that Ac/dc Power Systems nodes are n, DC node number is nc, then the number for exchanging node is na=n-
nc.By the order of AC and DC to node carry out order sequence.
2.1) node power equation：
Wherein, i=na+ k, k=1,2 ..., nc, positive sign represents inverter in formula, and negative sign represents rectifier.With AC system
Network equation contrasts, and adds Vdk, IdkWithThree variables, they represent DC node voltage, Injection Current and electricity respectively
Angle between current voltage is the power-factor angle of transverter.ΔPiRepresent to give active amount of unbalance；ΔQiRepresent given nothing
Work(amount of unbalance；PisRepresent given active power；QisRepresent given reactive power；ViRepresent the voltage of node i；VjRepresent
Node j voltage；θijRepresent the phase angle difference between node i and node j；GijRepresent the real part of admittance matrix；BijRepresent admittance square
The imaginary part of battle array.Because equation adds the number of unknown quantity, it is therefore desirable to which other equations are as supplement.
2.2) transverter fundamental equation
For transverter k, there is equation below：
Wherein, Δ d1k、Δd2kRepresent DC voltage amount of unbalance；VdkTransverter DC voltage is represented,Represent the change of current
Transformer alternating side line voltage perunit value, IdkRepresent the DC current of transverter；XckConverter power transformer k equivalent impedance is represented,
kTkRepresent the no-load voltage ratio of converter power transformer, kγFor close to 1 constant, θdkTransverter k pilot angles are represented,Represent the work(of transverter
Rate factor angle.
2.3) DC network equation
It is referred to as DC network equation for describing the equation of direct current transportation model, typically with following canonical form：
Wherein, Δ d3kRepresent the amount of unbalance of transverter output DC current, IdkRepresent transverter k DC current；Vdj
Represent the DC voltage of j-th of DC node, gdkjRepresent the nodal-admittance matrix member of the DC network after cancellation contact node
Element, voltage x current represents the voltage and current of DC line in formula.For a simple two-terminal direct current transmission system, direct current
Network equation is simplified as：
In formula, R represents the resistance of DC line；Id1Represent the electric current of 1 end DC node；Id2Represent 2 end DC nodes
Electric current；If the resistance of DC line is sufficiently small, V can be approximately consideredd1=Vd2, Id1=Id2。
2.4) governing equation
Because the fundamental equation and DC network equation in transverter introduce two new variables again, so must increase again
Two equations are added to ensure that equation has unique solution, generally using the governing equation of transverter and inverter as supplement equation, and
And the variable of the two equations has independence.
Control for transverter generally there are in the following manner：
1. determine pilot angle control：cosθd-cosθds=0；θdRepresent converter Control angle, θdsRepresent given pilot angle；
2. rated transformation ratio controls：kT-kTs=0；kTRepresent converter transformers no-load voltage ratio, kTsIt is represented to rated transformation ratio；
3. Given current controller：Id-Ids=0；IdRepresent transverter output direct current, IdsRepresent given direct current definite value；
4. determine voltage control：Vd-Vds=0；VdRepresent transverter output DC voltage, VdsRepresent given DC voltage value；
5. constant dc power control：VdId-Pds=0, PdsRepresent transverter power output set-point.
Usual inverter is using the control mode for determining pilot angle and rated transformation ratio；Rectifier generally use determines electric current and rated transformation ratio
Control mode.In order that equation has versatility, governing equation is typically defined as following form：
Δd4k=d4k(Idk,Vdk,cosθdk,kTk)=0 (k=1,2 ..., nc)
Δd5k=d5k(Idk,Vdk,cosθdk,kTk)=0 (k=1,2 ..., nc)
In formula, d4kRepresent the function of rectifier no-load voltage ratio and current imbalance amount, Δ d4kRepresent rectifier control variable not
Aequum, d5kRepresent inverter no-load voltage ratio and the function of pilot angle amount of unbalance, Δ d5kRepresent the imbalance of inverter control variable
Amount, IdkRepresent transverter k DC current；VdkRepresent transverter k DC voltages；θdkRepresent transverter k pilot angles；kTkRepresent
The no-load voltage ratio of converter power transformer；Due to observing variable relevant with pilot angle in all formulas with cos θdkForm occur, to carry
The linearity of high equation, with cos θdkFor amount directly to be asked.
Node power equation, transverter fundamental equation, DC network equation and governing equation have collectively constituted alternating current-direct current
The Load flow calculation equation of combined hybrid system.Solve alternating current-direct current combined hybrid system trend, it is necessary to calculate all nodes voltage magnitude and
Phase angle, in addition, it also needs to calculate ncThe DC voltage of individual DC node, DC current, converter power transformer no-load voltage ratio, converter Control
Angle and five, converter power factor angle amount to be asked.Often increase a transverter, just will five supplement equations of increase.
3) it is internal node set I, boundary node set B and external node set by node division according to using needs
E, each interior element of gathering arrange from small to large according to node serial number.
Possess two kinds of fault-tolerant abilitys：It can interpolate that and do not occur simultaneously between set I, B and E first, and set I, B and E are simultaneously
The number of collection is equal to total nodes；Secondly will detect in set I whether include balance nodes, will be flat if do not included
The node that weighs is forced to retain as boundary node, into next step；If be directly entered comprising if in next step.
The first step of Static Equivalent seeks to make a distinction node, is needed to find out the internal node to be retained according to research
With appropriate boundary node, remaining node all eliminates.After the relevant parameter of equivalent network has been calculated, it is necessary to after to equivalence
System carries out Load flow calculation, and the accuracy of equivalent result is verified by contrasting the result for the trend for retaining network.Reservation system
In there is no a balance nodes, system will retain balance nodes automatically, retain system and handle as a group, and balance nodes conduct is in addition
One group, makes to have between balance nodes and reservation system by establishing virtual tributary between two groups and directly contacts.
As shown in Figure 7 divides group's processing structure figure, and balance nodes are handled as a reserve section point.Although balance
Do not contacted directly between node and built-in system, but pass through computing, matrix YEQIt is the matrix of a highly dense,
The off-diagonal element related to balance nodes can be thus considered as to the impedance value of virtual tributary, equilibrium establishment node saves with border
Virtual tributary between point.By such method, make to have between balance nodes and reservation system and directly contact.
4) node admittance subfunction makeYbus is called to form the bus admittance matrix of whole network, according to the node of division
Set, formed equivalent calculation blocking node admittance matrix YEE、YEB、YBBAnd YBE；
According to node-classification, the network equation of whole system is established, wherein Y matrixes are the node admittance squares of whole network
Battle array, rearranges to Y matrixes according to node division result, forms corresponding blocking node admittance matrix：
It is launched into following three equation：
Wherein：
In formula, former network parameter before equivalence：YEEAdmittance matrix between expression external node, YEBRepresent external node and side
Admittance matrix between boundary's node, YBERepresent admittance matrix between boundary node and external node, YBBRepresent to lead between boundary node
Receive matrix, YBIRepresent admittance matrix between boundary node and internal node, YIBRepresent admittance between internal node and boundary node
Matrix, YIIAdmittance matrix between expression internal node, VERepresent external node voltage, VBRepresent boundary node voltage, VIIn expression
Portion's node voltage, IIRepresent internal node Injection Current, IBRepresent boundary node Injection Current, IERepresent external node injection electricity
Stream；Network parameter after equivalence：YEQThe Equivalent admittance matrix of external node and boundary node is represented,Represent that external network is equivalent
Boundary node electric current is injected, boundary node is identical with internal node parameter before and after equivalence.
Above-mentioned blocked admittance matrix is exactly the meshed network equation after equivalent calculation, it can be seen that the network equation of system
In without VE, that is to say, that eliminate the influence of external network.Y is added in admittance matrixEQ, and the portion of other changes
Divide only YBBWith the Injection Current I of boundary nodeB, internal node do not change.For a linear system, above-mentioned equivalence
Calculating process is the process of rigorous equivalence, as long as the Injection Current I of external networkEDo not change, then in any method of operation
Under, waiting the trend of valve system should be consistent with former network.
5) calculating matrix YEQWith border equivalent capacitance C, border equivalent capacitance C process of asking for is provided by step 1.6), most
The equivalent branch parameters in border after equivalence are obtained eventually, thus calculate the equivalent injecting power S in borderEQ=Pi EQ+jQi E；Wherein, Pi EQ
Represent the equivalent injection active power of node i；Represent the equivalent injection reactive power of node i.
Because in systems in practice, this data of Injection Current are typically what can not be obtained, are generally all known line work(
Rate and node voltage value, therefore, the Injection Current of all nodes can be expressed as following forms：
In formula,Node Injection Current is represented,Represent node voltage,Represent node injecting power.
After electric current is shown with above-mentioned power meter, linear equation originally becomes a nonlinear equation expression, i.e.,：
Definition：
Then above formula can be expressed as：
In formula,External node injecting power is represented,Represent border section
Point injecting power,Represent internal node injecting power.
In the case of the power flow solutions of internal network and boundary node under knowing basic condition, border is calculated according to following formula
The equivalent injecting power of node：
Wherein, Pi EQRepresent the equivalent injection active power of node i；Represent the equivalent injection reactive power of node i；Vi 0WithBasic condition lower node i and node j busbar voltage modulus value are represented respectively；θiAnd θjRespectively represent basic condition lower node i and
Node j busbar voltages phase angle, θij=θi-θjRepresent the phase difference between node i and node j；gij+jbijRepresent and node i phase
The admittance value over the ground on chord road；gi0+jbi0Represent over the ground branch admittance of the branch road in i sides that be connected with node i.
The injecting power that boundary node is calculated using above-mentioned formula is very easy, it is only necessary to knows the flow data of boundary node
And the network topology structure being connected with boundary node.For a big system, possibly can not timely and accurately obtain
The flow data of external network, the related data of boundary node can be obtained in time by state estimator, therefore, above formula institute
The computational methods shown are more suitable for application on site.
6) new structured data body is formed, and preserves the basic data of system after equivalence, is defined as Rempc.Node definition
Principle be to be arranged according to internal node set and boundary node set order, alternator data and circuitry number in reservation system
According to new alternator data and branch data need to make corresponding change according to the node serial number rearranged.Then, will walk
The rapid equivalent branch parameters 5) obtained and border injecting power are respectively added in the branch road and node data of new data；
7) Load flow calculation is carried out to system after equivalence, contrasted with the calculation of tidal current in step 2), be i.e. contrast etc.
The front and rear power flow solutions for retaining branch road and node of value, selectively can export power flow solutions.
In above steps, to as follows to the processing method of DC line in Ac/dc Power Systems：
The method of traditional power network Static Equivalent both for AC system, equivalent essence be to network equation abbreviation,
Eliminate the influence of external node.But for Ac/dc Power Systems, the network equation of system containing direct current because send out
Very big change has been given birth to, unified bus admittance matrix can not be formed, method equivalent conventional WARD can not be also applicable.Therefore,
DC line is handled using equivalent branching and equivalent power method, converts it into what AC system equivalence can be handled
Model, equivalent calculation is then carried out again.
(1) equivalent branching
It is as shown in Figure 9 that DC line is equivalent into π molded line road, V according to power flow solutions1And θ1Represent rectification side transformer
Exchange the voltage magnitude and phase angle of node, V2And θ2Represent the voltage magnitude and phase angle of inverter side transformer alternating node, P1And Q1
The active power and reactive power that rectification side AC system is transmitted to straight-flow system, P are represented respectively2And Q2Inverter side is represented respectively
The active power and reactive power that AC system is transmitted to straight-flow system, positive direction is identical with the direction of arrow in figure, and direct current is equivalent
Into the admittance parameter on π molded line road：G and b is the series connection conductance and susceptance, b of equivalent branch road1And b2It is equivalent branch road the right and left
Shunt susceptance over the ground, this tittle are amounts to be asked.
The node voltage of AC systemWith admittance matrix element YijIt can be expressed as：
Yij=Gij+jBij
In formula, ei=Vicosθi, fi=Visinθi, ViAnd θiNode i voltage magnitude and phase are represented respectively；GijAnd BijPoint
Not Biao Shi branch road ij conductance and susceptance
The general type of the power flow equation of n node power system is：
In formula, PiAnd QiNode i injection active power and reactive power are represented respectively.
So as to obtain power flow equation corresponding to Fig. 9：
Wherein, θ12=θ1-θ2；Other specification is corresponding with parameter in Fig. 9.Line transmission work(can be obtained by Load flow calculation
Rate, and node voltage and phase angle, be finally calculated DC line be equivalent to Fig. 9 alternating current circuits parameter it is as follows：
Four formula cans calculate the parameter of equivalent branch road more than, but b generally be present1≠b2, that is to say, that etc.
π molded line road after effect is asymmetrical, it is necessary to which converting it into symmetrical π molded line road road could participate in calculating, and processing method is with locating
It is identical to manage Asymmetric Links method, equivalent branch road is changed into a symmetrical π molded line road and one is connected in parallel on circuit one end
Reactance or inductance.Isoboles is as shown in Figure 10, b1-2Represent the difference of substitutional connection the right and left shunt admittance over the ground.Pass through this
All DC lines in system can be processed into alternating current circuit by the processing mode of sample, therefore an Ac/dc Power Systems just become
For the system of a pure exchange, then calculated using the equivalence method of AC system.
(2) equivalent power method
It is when solving AC system equation using alternative iteration method, straight-flow system is equivalent into known to being connected in respective nodes
Its active and reactive power load.So equivalent power method is exactly the result according to Load flow calculation, by direct current component transmission
Power is equivalent into the generator for being connected on both sides exchange node, and the two exchange node definitions are PQ nodes.Equivalent process such as Figure 11
It is shown, in figureWithThe power of DC line first and last node-node transmission is represented respectively.
Equivalent power method is exactly that the power for directly transmitting DC line is equivalent waits check-in into two, and premise assumes that direct current
The power of conveying is constant.Therefore it may only be necessary to corresponding conversion is done according to the power flow solutions can of converter power transformer circuit.
Embodiment：The static system for describing the application present invention in detail below by specific embodiment is equivalent.Embodiment 1：
The node modular systems of IEEE 30；Embodiment 2：The Chinese node Ac/dc Power Systems of DianKeYuan 36.Specific embodiment calculating process
It is as follows with result：
Embodiment 1：
(1) the node modular systems of IEEE 30
Table 1 gives the detailed results of IEEE-30 node divisions.
The IEEE-30 node divisions of table 1
The check-in such as equivalent calculation, border (as PQ node processings) is carried out to the node example of standard 30 using equivalent program,
Boundary node virtual tributary impedance value, border shunt compensation data are as shown in table 2, table 3, table 4.
Check-in (the units such as the border of table 2：MW/MVAR)
The boundary node virtual tributary impedance value (pu.) of table 3
The border shunt compensation value (pu.) of table 4
In order to verify the accuracy of equivalent result, it is necessary to which the trend of system after system before equivalence and equivalence is compared.
Load flow calculation is carried out to the system after equivalence under the identical method of operation, as a result as shown in table 5.
The internal network trend error (unit of table 5：MW/MVAR)
It can be seen from Table 5 that in the case where the method for operation does not change, the power flow solutions of system and original after equivalence
System is basically identical.The comparison result of trend error is given before and after Figure 11 equivalences in trend Error Graph, can from Figure 11
Go out, the order of magnitude of the active error of circuit is 10-8, the order of magnitude of reactive power error is 10-7.Therefore system in the case of ground state, etc.
It is exactly accurate to be worth result.
(2) IEEE30 system operation modes change
When system operation mode changes, and particularly system needs idle increment, there is certain error in WARD equivalences.
In the case of disconnection fault now occurs for IEEE30 system branches 4-6, equivalent simulation analysis are carried out to system.Due to No. 11 sections
Point is PV node, and node is repartitioned first, using the node as cancellation node, the node the repartitioned such as institute of table 6
Show.
The node division of table 6
Consider that short circuit occurs for branch road 4-6, calculate the steady-state load flow of system after short circuit, then system is subjected to equivalent calculation, count
Calculate the steady-state load flow after equivalent system short-circuit.Steady-state load flow before equivalence and after equivalence is contrasted.Such as Figure 12 a, Figure 12 b institute
Show, under conditions of considering that the method for operation changes, the active and reactive power flow error of system after equivalence is preceding and equivalent.It can see
Go out, in the case of circuit 4-6 short circuits, under the conditions of the contrast method of operation is immovable, error amount has increased, but still exists
In the range of engineering receives.Effective power flow error is substantially remained within 5%, worst error 7%.Reactive power error substantially remains in
Within 10%, worst error 15%.As can be seen that reactive power error is slightly larger than active error, this, which is also that WARD is equivalent, itself consolidates
The defects of having, because when the internal system method of operation changes, certain change can occur for the injecting power of external system,
Particularly reactive power.And it is still to be calculated according to the situation of ground state to wait the border injecting power of valve system, therefore error meeting
Increase.But in general, after system operation mode changes, WARD equivalences still have good equivalent effect.
Embodiment 2：The Chinese node Ac/dc Power Systems of DianKeYuan 36.
By taking the Chinese node Ac/dc Power Systems of DianKeYuan 36 as an example, this report is respectively adopted and proposes equivalent branching and waits
Source Method is imitated, equivalent analysis is carried out to Ac/dc Power Systems.
(1) equivalent branching
The trend of the test system is calculated first.The exchange node power flow solutions (pu.) such as the institute of table 7 of DC line both sides
Show, wherein positive direction is identical with defined in Figure 13 a, Figure 13 b.
The power flow solutions of table 7
In table 7, P33And Q33Represent that node 33 injects active power and reactive power, P respectively34And Q34Node is represented respectively
34 injection active power and reactive power；V33WithThe voltage magnitude of node 33 and phase angle, V are represented respectively34WithSection is represented respectively
34 voltage magnitudes of point and phase angle.
By in the known quantity substitution formula in table 7, the parameter for calculating equivalent branch road is respectively：G=0.5820, b=-
7.3541 b1=0.05117, b2=0.61253.The method handled according to equivalent branch road handles related data, removes the He of bus 33
DC line parameter between 34, increase exchanges circuit 33-34, impedance parameter 0.0107+j0.1351, total capacitance b in parallelc
=0.1023, the shunt capacitance injecting power B=56.14MAVR of bus 34, MATLAB basic datas are changed according to result of calculation.
Node division is carried out to CEPRI-36.For convenience, this report retains several important generatings including balance nodes
Machine node, remaining node all eliminate, and node division result is as shown in table 8.
The CEPRI-36 node division results of table 8
Using equivalent program, equivalent calculation is carried out to test system.Figure 13 system and is waited after giving original system, processing
System retains the active and reactive trend comparing result of branch road after value.
(2) equivalent power method
According to power flow solutions, CEPRI-36 basic datas are changed, remove direct current branch 33-34, added in node 33 and 34
Load data (perunit value, rated power 100MW) P33+Q33=3.0015+j0.4270, go out to add load P in node 3434+
Q34=-2.9057+j0.1174.
Node-classification is identical with CEPRI-36 node divisions result in table 8.Using equivalent program, test system is carried out
Equivalent calculation.As shown in Figure 15 a~Figure 16 b, the trend contrast knot of system after system and equivalence after original system, processing is given
Fruit.
According to two above simulation result, can obtain as drawn a conclusion：
(1) equivalent power method and equivalent branching are used, in the case where keeping system operation mode not change, place
Power flow solutions are highly consistent before and after reason；
The result that (2) two kinds of processing methods obtain is essentially identical, and network power flow solutions are highly consistent before and after equivalence, by mistake
Poor very little.Therefore, equivalent result is exactly accurate.
The various embodiments described above are merely to illustrate the present invention, and wherein each implementation steps of method etc. are all to be varied from
, every equivalents carried out on the basis of technical solution of the present invention and improvement, it should not exclude the protection in the present invention
Outside scope.
Claims (10)
1. a kind of ac and dc systemses equivalence method equivalent based on WARD, it is characterised in that comprise the following steps：
1) each primary element model in WARD Equivalent Models is established, from each primary element model based on acquisition the whole network node
Data, and determine that data format is Matpower standard data formats or BPA data formats, if BPA data formats, then
Matpower reference formats are converted thereof into be calculated；
2) Load flow calculation is carried out to the whole network, obtains the whole network flow solution, power flow solutions are defined on to an entitled result structure
In body, form is similar with data structure；
3) it is internal node set I, boundary node set B and external node set E by node division, each interior element of gathering is pressed
Arranged from small to large according to node serial number；
4) node admittance subfunction makeYbus is called to form the bus admittance matrix of whole network, according to the set of node of division
Close, formed equivalent calculation blocking node admittance matrix；
5) calculating matrix YEQThe equivalent branch parameters in border after equivalence are obtained with border equivalent capacitance C, it is equivalent thus to calculate border
Injecting power SEQ=Pi EQ+jQi EQ；
6) new structured data body is formed, and preserves the basic data of system after equivalence, is defined as Rempc, step 5) is added
Into new construction data volume；
7) Load flow calculation is carried out to system after equivalence, contrasts the equivalent front and rear power flow solutions for retaining branch road and node, selectively
Power flow solutions are exported.
A kind of 2. ac and dc systemses equivalence method equivalent based on WARD as claimed in claim 1, it is characterised in that：The step
It is rapid 1) in, primary element model include circuit model, generator and load model, parallel element model, Asymmetric Links model,
Transformer branch and border electric capacity.
A kind of 3. ac and dc systemses equivalence method equivalent based on WARD as claimed in claim 1, it is characterised in that：The step
It is rapid 2) in, to the whole network carry out Load flow calculation include node power equation, transverter fundamental equation, DC network equation and control
Equation.
A kind of 4. ac and dc systemses equivalence method equivalent based on WARD as claimed in claim 3, it is characterised in that：The section
Point power equation：
Wherein, i=na+ k, k=1,2 ..., nc, positive sign represents inverter in formula, and negative sign represents rectifier.With AC system network
Equation contrasts, and adds Vdk, IdkWithThree variables, they represent DC node voltage, Injection Current and voltage electricity respectively
Angle between stream is the power-factor angle of transverter.ΔPiRepresent to give active amount of unbalance；ΔQiRepresent it is given it is idle not
Aequum；PisRepresent given active power；QisRepresent given reactive power；ViRepresent the voltage of node i；VjRepresent node
J voltage；θijRepresent the phase angle difference between node i and node j；GijRepresent the real part of admittance matrix；BijRepresent admittance matrix
Imaginary part.
A kind of 5. ac and dc systemses equivalence method equivalent based on WARD as claimed in claim 3, it is characterised in that：It is described to change
Device fundamental equation is flowed, for transverter k, there is equation below：
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Wherein, Δ d1k、Δd2kRepresent DC voltage amount of unbalance；VdkTransverter DC voltage is represented,Represent change of current transformation
Device AC line voltage perunit value, IdkRepresent the DC current of transverter；XckRepresent converter power transformer k equivalent impedance, kTkTable
Show the no-load voltage ratio of converter power transformer, kγFor close to 1 constant, θdkTransverter k pilot angles are represented,Represent the power factor of transverter
Angle.
A kind of 6. ac and dc systemses equivalence method equivalent based on WARD as claimed in claim 3, it is characterised in that：It is described straight
The canonical form of flow network equation：
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Wherein, Δ d3kRepresent the amount of unbalance of transverter output DC current, IdkRepresent transverter k DC current；VdjRepresent
The DC voltage of j-th of DC node, gdkjRepresent the nodal-admittance matrix element of the DC network after cancellation contact node, formula
Middle voltage x current represents the voltage and current of DC line.For a simple two-terminal direct current transmission system, DC network
Equation simplification is as follows：
It is as follows for a simple two-terminal direct current transmission system, DC network equation simplification：
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In formula, R represents the resistance of DC line；Id1Represent the electric current of 1 end DC node；Id2Represent the electric current of 2 end DC nodes；
If the resistance of DC line is sufficiently small, V can be approximately consideredd1=Vd2, Id1=Id2。
A kind of 7. ac and dc systemses equivalence method equivalent based on WARD as claimed in claim 3, it is characterised in that：The control
Equation processed：
Δd4k=d4k(Idk,Vdk,cosθdk,kTk)=0 (k=1,2 ..., nc)
Δd5k=d5k(Idk,Vdk,cosθdk,kTk)=0 (k=1,2 ..., nc)
In formula, d4kRepresent the function of rectifier no-load voltage ratio and current imbalance amount, Δ d4kRepresent the imbalance of rectifier control variable
Amount, d5kRepresent inverter no-load voltage ratio and the function of pilot angle amount of unbalance, Δ d5kThe amount of unbalance of inverter control variable is represented,
IdkRepresent transverter k DC current；VdkRepresent transverter k DC voltages；θdkRepresent transverter k pilot angles；kTkRepresent the change of current
The no-load voltage ratio of transformer；Due to observing variable relevant with pilot angle in all formulas with cos θdkForm occur, for raising side
The linearity of journey, with cos θdkFor amount directly to be asked.
A kind of 8. ac and dc systemses equivalence method equivalent based on WARD as claimed in claim 1, it is characterised in that：The step
It is rapid 3) in, need to possess two kinds of fault-tolerant abilitys：Determine not occur simultaneously between set I, B and E first, and set I, B and E union
Number is equal to total nodes；Secondly whether balance nodes are included in detection set I, if do not included, balance nodes is made
For boundary node force retain, into next step, if be directly entered comprising if in next step.
A kind of 9. ac and dc systemses equivalence method equivalent based on WARD as claimed in claim 1, it is characterised in that：The step
It is rapid 5) in, border equivalent capacity C is：
Pure routine calculation method：
C (k)=C (k)+ykj
In formula, k ∈ i；
Transformer lines computational methods, and boundary node is first node：
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Wherein, Yij(i ≠ j) represents the negative value of the line admittance of node i and node j composition branch roads, the relevant parameter table of the branch road
It is shown as：Line admittance yij, the total admittance b over the ground of circuitij, transformer voltage ratio τij, phase shift θij。
A kind of 10. ac and dc systemses equivalence method equivalent based on WARD as claimed in claim 1, it is characterised in that：It is described
In step 6), the principle of node definition is arranged according to internal node set and boundary node set order, in reservation system
Alternator data and branch data, new alternator data and branch data need to make phase according to the node serial number rearranged
The change answered；Then, increased equivalent virtual tributary and border capacitance data are respectively added to the branch road and node of new data
In data.
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| CN109301856A (en) * | 2018-09-07 | 2019-02-01 | 山东大学 | A kind of direct current layered structure modeling and analysis methods and system |
| CN110676852A (en) * | 2019-08-26 | 2020-01-10 | 重庆大学 | Improved extreme learning machine rapid probability load flow calculation method considering load flow characteristics |
| CN111262249A (en) * | 2019-12-20 | 2020-06-09 | 国网新疆电力有限公司 | Power grid flow simulation method and system |
| CN112054515A (en) * | 2020-08-28 | 2020-12-08 | 武汉大学 | Receiving-end power grid DC receiving capacity detection method based on multi-objective optimization |
| CN112685981A (en) * | 2020-12-28 | 2021-04-20 | 南方电网科学研究院有限责任公司 | Static equivalence method and device for power system, terminal equipment and storage medium |
| CN112952841A (en) * | 2021-02-05 | 2021-06-11 | 杭州沃瑞电力科技有限公司 | Power transmission network step-by-step optimization reconstruction method for controlling power grid short-circuit current level |
| CN113270861A (en) * | 2021-04-14 | 2021-08-17 | 国网甘肃省电力公司经济技术研究院 | Limit capacity calculation method for accessing renewable energy into power grid |
| CN113746097A (en) * | 2021-09-27 | 2021-12-03 | 杭州电力设备制造有限公司 | Power system analysis method, system, equipment and storage medium |
| CN116822436A (en) * | 2023-06-30 | 2023-09-29 | 四川大学 | Oscillation risk sensitivity analysis method for direct-current transmission end alternating-current system |
| CN118281883A (en) * | 2024-06-03 | 2024-07-02 | 中国电力科学研究院有限公司 | Data adjustment method and system based on tide voltage intensity |
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| CN108448549A (en) * | 2018-05-09 | 2018-08-24 | 华中科技大学 | The flexible direct current line protection method of power is measured based on current-limiting reactor |
| CN109301856A (en) * | 2018-09-07 | 2019-02-01 | 山东大学 | A kind of direct current layered structure modeling and analysis methods and system |
| CN109301856B (en) * | 2018-09-07 | 2021-05-07 | 山东大学 | Modeling analysis method and system for direct-current layered structure |
| CN110676852A (en) * | 2019-08-26 | 2020-01-10 | 重庆大学 | Improved extreme learning machine rapid probability load flow calculation method considering load flow characteristics |
| CN110676852B (en) * | 2019-08-26 | 2020-11-10 | 重庆大学 | Improved extreme learning machine rapid probability load flow calculation method considering load flow characteristics |
| CN111262249A (en) * | 2019-12-20 | 2020-06-09 | 国网新疆电力有限公司 | Power grid flow simulation method and system |
| CN111262249B (en) * | 2019-12-20 | 2024-01-30 | 国网新疆电力有限公司 | Power grid tide simulation method and system |
| CN112054515A (en) * | 2020-08-28 | 2020-12-08 | 武汉大学 | Receiving-end power grid DC receiving capacity detection method based on multi-objective optimization |
| CN112685981A (en) * | 2020-12-28 | 2021-04-20 | 南方电网科学研究院有限责任公司 | Static equivalence method and device for power system, terminal equipment and storage medium |
| CN112685981B (en) * | 2020-12-28 | 2024-05-07 | 南方电网科学研究院有限责任公司 | Static equivalence method and device for power system, terminal equipment and storage medium |
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| CN113270861A (en) * | 2021-04-14 | 2021-08-17 | 国网甘肃省电力公司经济技术研究院 | Limit capacity calculation method for accessing renewable energy into power grid |
| CN113270861B (en) * | 2021-04-14 | 2022-10-11 | 国网甘肃省电力公司经济技术研究院 | Limit capacity calculation method for accessing renewable energy into power grid |
| CN113746097A (en) * | 2021-09-27 | 2021-12-03 | 杭州电力设备制造有限公司 | Power system analysis method, system, equipment and storage medium |
| CN113746097B (en) * | 2021-09-27 | 2023-09-29 | 杭州电力设备制造有限公司 | Power system analysis method, system, equipment and storage medium |
| CN116822436A (en) * | 2023-06-30 | 2023-09-29 | 四川大学 | Oscillation risk sensitivity analysis method for direct-current transmission end alternating-current system |
| CN116822436B (en) * | 2023-06-30 | 2024-02-27 | 四川大学 | Oscillation risk sensitivity analysis method for direct-current transmission end alternating-current system |
| CN118281883A (en) * | 2024-06-03 | 2024-07-02 | 中国电力科学研究院有限公司 | Data adjustment method and system based on tide voltage intensity |
| CN118501791A (en) * | 2024-07-18 | 2024-08-16 | 济南市计量检定测试院 | Metering detection data precision evaluation method and system |
| CN118501791B (en) * | 2024-07-18 | 2024-10-01 | 济南市计量检定测试院 | Metering detection data precision evaluation method and system |
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