CN103529275A - Short-circuit current analysis method and device of regional power grid - Google Patents

Abstract

The invention provides a short-circuit current analysis method and a device of a regional power grid. The method comprises the steps of regionalizing a power grid system: dividing a region with a short-circuit current level to be analyzed and calculated into a study area, dividing a region directly communicated with the study area into a boundary area, and dividing a region except the study area and the boundary area into an external area, performing equivalent simplification on the boundary area and the external area to form an equivalent boundary area, obtaining an equivalent power grid system consisting of the study area and the equivalent boundary area, and analyzing and calculating the short-circuit current level of the study area according to the equivalent power grid system. The method and the device solve the technical problems that the calculation accuracy of short-circuit current is difficult to guarantee in the prior art, and the data size during short-circuit current analysis is large, and achieves the technical effects of reducing the data size and calculation load during the short-circuit current analysis on the basis of ensuring the calculation accuracy of the short-circuit current.

Description

Area power grid Analysis of Short-Circuit Current method and apparatus

Technical field

The present invention relates to technical field of power systems, particularly a kind of area power grid Analysis of Short-Circuit Current method and apparatus.

Background technology

Calculation of short-circuit current; be a requisite basic calculating in the design and running of electric system, the result of calculation of short-circuit current is generally applied to the determining etc. of the determining of selection, protective relaying device, Main Wire Connection Scheme and the method for operation of electrical equipment and current－carrying conductor.In addition, carrying out the transient stability analysis of electric system, determining that transmission line of electricity also all must carry out calculation of short-circuit current to the aspects such as interference of communication.

In recent years along with the continuous expansion of electric system scale; contact between electrical network strengthens gradually; the development of extensive interconnected network can realize the reasonable development of resource and distribute, improves the reliability of power supply rationally and the economy of operation on the one hand; reinforcement due to electric network composition is shortened electrical distance on the other hand; the short-circuit current of part plant stand increases more; the rupturing capacity that has even surpassed switch, short-circuit current problem has more and more caused the attention of power planning, management and running department.

At present, when certain electrical network is carried out to calculation of short-circuit current, often only pay close attention to this electrical network location short circuit current level of (can be called survey region), yet, because mutually can exert an influence and disturb between electrical network, how to guarantee survey region to carry out the accuracy of calculation of short-circuit current, just need to the region except survey region in electric system be calculated and be analyzed.If the data of whole electric power networks are all carried out to analytical calculation, computing velocity will be very slow so, also needs other the regional electric network data except survey region to safeguard simultaneously, and this will greatly increase data volume and the calculated amount of Analysis of Short-Circuit Current.

Simultaneously, continuous expansion along with electrical network scale, in order to guarantee the accuracy of calculation of short-circuit current, the data volume of operation of power networks personnel when carrying out Analysis of Short-Circuit Current calculating becomes more and more huger, the data volume of carrying out data analysis is also more and more, so also just must cause the requirement of Liao Dui simulation software and allocation of computer to become more and more higher.Meanwhile, owing to being subject to the restriction of the algorithm of program own, also there is certain requirement to the scale of electrical network in some business softwares.

How, when guaranteeing calculation of short-circuit current precision, the data volume while reducing Analysis of Short-Circuit Current, not yet proposes effective solution at present.

Summary of the invention

The invention provides a kind of area power grid Analysis of Short-Circuit Current method and apparatus, at least to solve in prior art, be difficult to when guaranteeing calculation of short-circuit current precision the technical matters of the data volume while reducing Analysis of Short-Circuit Current.

The embodiment of the present invention provides a kind of area power grid Analysis of Short-Circuit Current method, comprise: network system is carried out to region division: by the regional classification that needs analytical calculation short circuit current level, be survey region, by there is the regional classification of directly contact with survey region, being borderline region, is perimeter by the regional classification except survey region and borderline region; Borderline region and perimeter are carried out to equivalent simplification, form the borderline region after equivalence, the network system after the equivalence that obtains being formed by the borderline region after survey region and equivalence; According to the network system after equivalence, the short circuit current level of analytical calculation survey region.

In one embodiment, borderline region and perimeter are carried out to equivalent simplification, form the borderline region after equivalence, network system after the equivalence that obtains being comprised of the borderline region after survey region and equivalence, comprising: according to the bus admittance matrix of the sequential build network system of perimeter, borderline region and survey region; Utilize the part in Gaussian elimination method cancellation bus admittance matrix peripheral region, form the equivalent posterior nodal point admittance matrix that only retains borderline region and survey region; The variable quantity matrix of the matrix element that in certainty equivalents posterior nodal point admittance matrix, borderline region is corresponding; According to the generator increasing in the borderline region after described variable quantity matrix certainty equivalents, the connection branch road of increase, and the reactance parameter of generator increasing and the reactance parameter of the connection branch road of increase; According to the connection branch road of the generator of the increase of determining, increase, the reactance parameter of the connection branch road of the reactance parameter of the generator of increase and increase carries out network reconfiguration and forms the network system after equivalence.

In one embodiment, the reactance parameter according to the connection branch road increasing in the borderline region after described variable quantity matrix certainty equivalents, comprising: the node number of determining the connection branch road two ends that increase; Get the negative inverse of element corresponding with the node number at two ends in variable quantity matrix, as the reactance parameter of the connection branch road increasing.

In one embodiment, the reactance parameter according to the generator increasing in the borderline region after described variable quantity matrix certainty equivalents, comprising: the node number of determining the node being connected with the generator increasing; Each element on this node number in the admittance that is connected branch road direct connected with the node of this node number in perimeter, variable quantity matrix is expert at obtains resultant admittance as sum operation; Get the inverse of resultant admittance as the reactance parameter of the generator increasing.

In one embodiment, the variable quantity matrix of the matrix element that in certainty equivalents posterior nodal point admittance matrix, borderline region is corresponding, comprising: the number of determining node in borderline region; In the situation that the number of node is less than predetermined threshold in borderline region, adopt the method that linear equation solves to calculate variable quantity matrix.

In one embodiment, described predetermined threshold is 6.

The embodiment of the present invention also provides a kind of area power grid Analysis of Short-Circuit Current device, comprise: module is divided in region, for network system is carried out to region division: be survey region by the regional classification that needs analytical calculation short circuit current level, by there is the regional classification of directly contact with survey region, being borderline region, is perimeter by the regional classification except survey region and borderline region; Equivalent Simplification module, for borderline region and perimeter are carried out to equivalent simplification, forms the borderline region after equivalence, the network system after the equivalence that obtains being comprised of the borderline region after survey region and equivalence; Analysis module, for according to the network system after equivalence, the short circuit current level of analytical calculation survey region.

In one embodiment, described Equivalent Simplification module comprises: construction unit, for the bus admittance matrix of the sequential build network system according to perimeter, borderline region and survey region; Simplified element, for utilizing the part in Gaussian elimination method cancellation bus admittance matrix peripheral region, forms the equivalent posterior nodal point admittance matrix that only retains borderline region and survey region; Matrix determining unit, for the variable quantity matrix of matrix element corresponding to certainty equivalents posterior nodal point admittance matrix borderline region; Parameter determining unit, for the generator increasing according to the borderline region after described variable quantity matrix certainty equivalents, the connection branch road of increase, and the reactance parameter of generator increasing and the reactance parameter of the connection branch road of increase; Reconfiguration unit, for according to the generator increasing, the connection branch road of increase, the reactance parameter of the reactance parameter of the generator of increase and the connection branch road that increases carries out network reconfiguration and forms the network system after equivalence.

In one embodiment, described parameter determining unit comprises: first segment period is determined subelement, for determining the node number at the connection branch road two ends that increase; The first parameter is determined subelement, for getting the negative inverse of the element that variable quantity matrix is corresponding with the node number at two ends, as the reactance parameter of the connection branch road increasing.

In one embodiment, described parameter determining unit comprises: second section period is determined subelement, for determining the node number of the node being connected with the generator increasing; Cumulative unit, obtains resultant admittance for each element on this node number in the directly connected admittance that is connected branch road of the node of perimeter and this node number, variable quantity matrix is expert at as sum operation; The second parameter is determined subelement, for getting the inverse of resultant admittance as the reactance parameter of the generator increasing.

In one embodiment, described matrix determining unit comprises: nodes is determined subelement, for determining the number of borderline region node; Computation subunit, in the situation that the number of borderline region node is less than predetermined threshold, adopts the method that linear equation solves to calculate variable quantity matrix.

In one embodiment, described predetermined threshold is 6.

In embodiments of the present invention, by the regional classification that needs analytical calculation short circuit current level in network system, it is survey region, then by there is the regional classification of directly contact with survey region, be borderline region, by the regional classification except survey region and borderline region, it is perimeter, then by this network system Equivalent Simplification, be the network system that only comprises the borderline region after survey region and equivalence, finally by the short circuit current level of the network system analytical calculation survey region after equivalence, because no longer there is perimeter in the network system after Equivalent Simplification, therefore when analytical calculation short circuit current level, required data volume will obviously reduce.Efficiently solve by the way in prior art and be difficult to when guaranteeing calculation of short-circuit current precision, the technical matters of the data volume while reducing Analysis of Short-Circuit Current, reached and guaranteed on the basis of calculation of short-circuit current precision, the data volume while reducing Analysis of Short-Circuit Current and the technique effect of calculated amount.

Accompanying drawing explanation

Accompanying drawing described herein is used to provide a further understanding of the present invention, forms the application's a part, does not form limitation of the invention.In the accompanying drawings:

Fig. 1 is the process flow diagram of the area power grid Analysis of Short-Circuit Current method of the embodiment of the present invention;

Fig. 2 is the process flow diagram that carries out Equivalent Network simplification of the embodiment of the present invention;

Fig. 3 is the process flow diagram of the area power grid Analysis of Short-Circuit Current method specific embodiment of the embodiment of the present invention;

Fig. 4 is that schematic diagram is divided in the network structure region of the embodiment of the present invention;

Fig. 5 is the schematic diagram of the line admittance of interconnection between each region of the embodiment of the present invention;

Fig. 6 is the network connection figure of certain node in borderline region after the Equivalent Simplification of the embodiment of the present invention;

Fig. 7 is that the network structure of the IEEE39 node of the embodiment of the present invention is divided schematic diagram;

Fig. 8 is the structured flowchart of the area power grid Analysis of Short-Circuit Current device of the embodiment of the present invention.

Embodiment

For making the object, technical solutions and advantages of the present invention clearer, below in conjunction with embodiment and accompanying drawing, the present invention is described in further details.At this, exemplary embodiment of the present invention and explanation thereof are used for explaining the present invention, but not as a limitation of the invention.

A kind of area power grid Analysis of Short-Circuit Current is provided in embodiments of the present invention, and as shown in Figure 1, the method comprises the following steps:

Step 101: network system is carried out to region division: be survey region by the regional classification that needs analytical calculation short circuit current level, by there is the regional classification of directly contact with survey region, being borderline region, is perimeter by the regional classification except survey region and borderline region;

Step 102: borderline region and perimeter are carried out to equivalent simplification, form the borderline region after equivalence, the network system after the equivalence that obtains being formed by the borderline region after survey region and equivalence;

Step 103: according to the network system after equivalence, the short circuit current level of analytical calculation survey region.

In the above-described embodiments, by the regional classification that needs analytical calculation short circuit current level in network system, it is survey region, then by there is the regional classification of directly contact with survey region, be borderline region, by the regional classification except survey region and borderline region, it is perimeter, then by this network system Equivalent Simplification, be the network system that only comprises the borderline region after survey region and equivalence, finally by the short circuit current level of the network system analytical calculation survey region after equivalence, because no longer there is perimeter in the network system after Equivalent Simplification, therefore when analytical calculation short circuit current level, required data volume will obviously reduce.Efficiently solve by the way in prior art and be difficult to when guaranteeing calculation of short-circuit current precision, the technical matters of the data volume while reducing Analysis of Short-Circuit Current, reached and guaranteed on the basis of calculation of short-circuit current precision, the data volume while reducing Analysis of Short-Circuit Current and the technique effect of calculated amount.

In one embodiment, can carry out by the bus admittance matrix of network system the Equivalent Simplification of network system, in one embodiment, above-mentioned steps 102 is carried out equivalent simplification by borderline region and perimeter, form the borderline region after equivalence, network system after the equivalence that obtains being comprised of the borderline region after survey region and equivalence, can as shown in Figure 2, comprise the following steps:

Step 201: according to the bus admittance matrix of the sequential build network system of perimeter, borderline region and survey region;

Step 202: utilize the part in Gaussian elimination method cancellation bus admittance matrix peripheral region, form the equivalent posterior nodal point admittance matrix that only retains borderline region and survey region;

Step 203: the variable quantity matrix of the matrix element that in certainty equivalents posterior nodal point admittance matrix, borderline region is corresponding;

Step 204: according to the generator increasing in the borderline region after described variable quantity matrix certainty equivalents, the connection branch road of increase, and the reactance parameter of generator increasing and the reactance parameter of the connection branch road of increase;

Step 205: according to the connection branch road of the generator of the increase of determining, increase, the reactance parameter of the connection branch road of the reactance parameter of the generator of increase, increase and generator be connected connected mode between branch road and carry out network reconfiguration and form the network system after equivalence.

, first build the bus admittance matrix of network system, then by Gaussian elimination method, eliminate matrix element corresponding to bus admittance matrix peripheral region, after Gaussian elimination, matrix element corresponding to perimeter will be by equivalence in matrix element corresponding to borderline region, finally can find that variation has occurred the matrix element that in the bus admittance matrix after Equivalent Simplification, only borderline region is corresponding, can be directly according to the generator increasing in borderline region in the electric network composition after the variation certainty equivalents of matrix element corresponding to borderline region be connected branch road, and the generator and the reactance parameter that is connected branch road that increase.When carrying out Equivalent Simplification reconstruct network system, can keep in borderline region original node and to be connected branch road all constant, but by newly-increased generator be connected branch road and add the relevant position in borderline region to.

Concrete, the reactance parameter of generator increasing according to the borderline region after described variable quantity matrix certainty equivalents and the reactance parameter of the connection branch road of increase can comprise:

1) determine the node number at the connection branch road two ends that increase; Get the negative inverse of element corresponding with the node number at two ends in variable quantity matrix, as the reactance parameter of the connection branch road increasing;

2) determine the node number of the node being connected with the generator increasing; Each element on this node number in the admittance that is connected branch road direct connected with the node of this node number in perimeter, variable quantity matrix is expert at obtains resultant admittance as sum operation; Get the inverse of resultant admittance as the reactance parameter of the generator increasing.

For the principle of above-mentioned steps 201 to 205 is specifically described, the area power grid Analysis of Short-Circuit Current method embodiment of the present invention being provided below in conjunction with a concrete example is specifically described.

In the present embodiment, area power grid Analysis of Short-Circuit Current method as shown in Figure 3, comprises the following steps:

Step 301: region is divided

Concrete, choose and need the area of analytical calculation short circuit current level as survey region, exist the area of directly contact as borderline region with survey region, the area except survey region and borderline region is as perimeter.After network is divided, survey region is connected by interconnection with borderline region, and borderline region is connected by interconnection with perimeter, and survey region and perimeter do not exist and contact directly.

Step 302: network abbreviation

Concrete, according to the sequential build total system bus admittance matrix Y of perimeter, borderline region and survey region.For example: can utilize Gaussian elimination method to carry out the Equivalent Simplification of network, with the part in cancellation Y peripheral region, form the bus admittance matrix after the equivalence that only retains borderline region and survey region

Step 303: borderline region network reconfiguration

Utilize the equivalent posterior nodal point admittance matrix generating in interconnection parameter between survey region and borderline region and above-mentioned steps 302 in Partial Elements, borderline region network is reconstructed.Wherein, above-mentioned border networks reconstruct comprises: interconnection reconstruct and generator reconstruct also need to calculate after reconstruct the reactance parameter of newly-increased element (comprise newly-increased generator and increase newly and be connected branch road) in network simultaneously.

Step 304: carry out Analysis of Short-Circuit Current according to the network after reconstruct.

Below above-mentioned steps 302 and step 303 are specifically described:

In above-mentioned steps 302 network abbreviations, when electrical network is carried out to analytical calculation, in order to reduce calculator memory and to reduce personnel's workload, the part that does not need to analyze can be waited the simplification of value to process in network.Be the schematic diagram that network structure region is divided as shown in Figure 4, the system of take is as shown in Figure 4 example, and the set of node of survey region represents with A, and the set of node of borderline region represents with B, and the set of node of perimeter represents with C.

According to the order of perimeter, borderline region and survey region, formed system-wide bus admittance matrix Y, according to bus admittance matrix and the reciprocal feature of nodal impedance matrix, shown in the equation formula 1 of partitioned matrix form:

$\left[\begin{array}{ccc}{Y}_{\mathrm{CC}}& Y_{\mathrm{CB}}& 0\\ Y_{\mathrm{BC}}& Y_{\mathrm{BB}}& Y_{\mathrm{BA}}\\ 0& Y_{\mathrm{AB}}& Y_{\mathrm{AA}}\end{array}\right]*\left[\begin{array}{ccc}{Z}_{\mathrm{CC}}& Z_{\mathrm{CB}}& Z_{\mathrm{CA}}\\ Z_{\mathrm{BC}}& Z_{\mathrm{BB}}& Z_{\mathrm{BA}}\\ Z_{\mathrm{AC}}& Z_{\mathrm{AB}}& Z_{\mathrm{AA}}\end{array}\right]=\left[\begin{array}{ccc}{E}_{\mathrm{CC}}& 0& 0\\ 0& E_{\mathrm{BB}}& 0\\ 0& 0& E_{\mathrm{AA}}\end{array}\right]$ (formula 1)

Wherein, Y represents bus admittance matrix, and Z represents nodal impedance matrix, E representation unit matrix.

At present, what power industry mainly adopted when calculating short-circuit current is equivalent voltage source method, by solving the short-circuit impedance of trouble spot, calculates short-circuit current value.According to the character of nodal impedance matrix, element Z on its diagonal line _kkresulting impedance over the ground for seeing into whole network from node k, also claims self-impedance or input impedance, Z when electrical network generation metallic short circuit _kkbe short-circuit impedance.

Due to when carrying out area power grid calculation of short-circuit current, only need to be concerned about the short circuit current level of each plant stand in survey region, only need to calculate partitioned matrix Z _aAelement on middle diagonal line, therefore, its corresponding computing formula as shown in Equation 2.

$\left[\begin{array}{ccc}{Y}_{\mathrm{CC}}& Y_{\mathrm{CB}}& 0\\ Y_{\mathrm{BC}}& Y_{\mathrm{BB}}& Y_{\mathrm{BA}}\\ 0& Y_{\mathrm{AB}}& Y_{\mathrm{AA}}\end{array}\right]*\left[\begin{array}{c}{Z}_{\mathrm{CA}}\\ Z_{\mathrm{BA}}\\ Z_{\mathrm{AA}}\end{array}\right]=\left[\begin{array}{c}0\\ 0\\ E_{\mathrm{AA}}\end{array}\right]$ (formula 2)

Utilize Gaussian elimination method cancellation perimeter C, can obtain:

$\left[\begin{array}{cc}{\tilde{Y}}_{\mathrm{BB}}& Y_{\mathrm{BA}}\\ Y_{\mathrm{AB}}& Y_{\mathrm{AA}}\end{array}\right]*\left[\begin{array}{c}{Z}_{\mathrm{BA}}\\ Z_{\mathrm{AA}}\end{array}\right]=\left[\begin{array}{c}0\\ E_{\mathrm{AA}}\end{array}\right]$ (formula 3)

Contrasting above-mentioned formula 2 and above-mentioned formula 3 can find out, variation has occurred the matrix element that in equivalent rear equation, only borderline region is corresponding, only has Y _bBthere is variation, equivalent front and back Y _bBvariable quantity be:

${\mathrm{\ΔY}}_{\mathrm{BB}}={\tilde{Y}}_{\mathrm{BB}}-Y_{\mathrm{BB}}=-Y_{\mathrm{BC}}{Y}_{\mathrm{CC}}^{-1}{Y}_{\mathrm{CB}}$ (formula 4)

By above-mentioned derivation, Y before and after Equivalent Simplification _bBvariation delta Y _bBcharacterize the impact of external node on internal node, according to the character of matrix transpose, can draw Δ Y _bBand Y _bBfor symmetric matrix, so borderline region can be reconstructed into an electric power networks that adds newly-increased branch road.

In the process of above-mentioned steps 303 borderline region network reconfigurations, according to the situation of change of bus admittance matrix in the equivalence course of deriving above, because the input data of calculation of short-circuit current software are the model parameters of power system component, therefore the matrix form after equivalence need to be converted to actual power network wiring structure, i.e. network reconfiguration problem.Network reconfiguration in calculation of short-circuit current process comprises interconnection reconstruct and generator reconstruct, also needs to calculate the reactance parameter of newly-increased element simultaneously.

Take the system shown in above-mentioned Fig. 4 as example, specifically describe the concrete methods of realizing of borderline region network reconfiguration in equivalence course.3 nodes in borderline region are called after b1, b2, b3 respectively, and between each region, the line admittance of interconnection as shown in Figure 5.

The node b1 of take in borderline region is example, introduces the interconnection reconstruct in borderline region network reconfiguration and the method for generator reconstruct after Equivalent Network, and solution procedure comprises the following steps:

S1: before equivalence, Y _bBthe self-admittance of middle b1 node is:

Y _bB(b1, b1)=y1+y4+y5+y6 (formula 5)

The transadmittance of b1 node is:

$\left\{\begin{array}{c}{Y}_{\mathrm{BB}}(b1,b2)=-y4\\ Y_{\mathrm{BB}}(b1,b3)=0\end{array}\right.$ (formula 6)

S2: after equivalence, by the known matrix Y of formula 4 _bBon the row element at middle b1 node place, there is newly-increased element, suppose the Δ Y being calculated by formula 4 _bBthe element that middle b1 is expert at is:

Δ Y _bB(b1)=[Δ y1 Δ y2 Δ y3] (formula 7)

By formula 5 to 7, can be drawn equivalent rear matrix

the row element at middle b1 node place is:

$\left\{\begin{array}{c}{\tilde{Y}}_{\mathrm{BB}}(b1,b1)=Y_{\mathrm{BB}}(b1,b1)+{\mathrm{\ΔY}}_{\mathrm{BB}}(b1,b1)\\ =y1+y4+y5+y6+\mathrm{\Δy}1\\ {\tilde{Y}}_{\mathrm{BB}}(b1,b2)=-y4+\mathrm{\Δy}2\\ {\tilde{Y}}_{\mathrm{BB}}(b1,b3)=\mathrm{\Δy}3\end{array}\right.$ (formula 8)

According to the requirement of network abbreviation and Δ Y _bB, feature, can be in the hope of the network connection of Equivalent Simplification posterior nodal point b1 as shown in Figure 6, transadmittance part in formula 8 can be found out, between node b1 and node b2, newly-increased admittance is-circuit of Δ y2, between node b1 and node b3, newly-increased admittance is-circuit of Δ y3, self-admittance part by formula 8 can be found out, after equivalent there is new branch road over the ground in b1 node, short-circuit impedance concept in calculation of short-circuit current is known, branch road can equivalence become generator branch road over the ground, and the subtranient reactance of newly-increased generator is X ' ' _d(being converted to admittance is y ' ').

As seen from Figure 6, for b1 node, newly-increased can partly determine by the transadmittance in formula 7 line parameter circuit value of b2, b3 node, for equivalent generator reactance parameter, can not directly obtain, network structure in Fig. 6 can draw, equivalent after the self-admittance of b1 node be:

${\tilde{Y}}_{\mathrm{BB}}(b1,b1)=y1+y4-\mathrm{\Δy}2-\mathrm{\Δy}3+y^{\′\′}$ (formula 9)

In contrast equation 8 and formula 9

expression formula, can obtain:

Y ' '=(y5+y6)+(Δ y1+ Δ y2+ Δ y3) (formula 10)

By formula 10, can be found out, in y ' ' expression formula first is be connected with the perimeter admittance sum (the admittance sum that is eliminated circuit being connected with node b1) of circuit of node b1, and second is matrix Δ Y _bBeach element sum that middle node b1 is expert at.

By above-mentioned analysis, can be found out, only need to calculate the variable quantity of the matrix element that in the admittance matrix after Equivalent Simplification, borderline region is corresponding, just can determine simply the reactance parameter with the generator that in borderline region, each node is connected by interconnection, and the reactance parameter of the connection branch road increasing between each node in borderline region, thereby realize network reconfiguration.

According to above-mentioned Fig. 6, formula 8 and formula 10, can draw newly-increased branch road relevant to node b1 in borderline region and the reactance parameter of newly-increased generator, concrete parameter is as shown in table 1:

Table 1

In borderline region, the processing mode of node b2, b3 is identical with the processing mode of node b1, does not repeat them here.

By above-mentioned Equivalent Simplification step, can find out, only need calculate Δ Y _bB, just can simply obtain the reactance parameter that borderline region increases element newly.By above-mentioned formula 4, can be found out Δ Y _bBsolve in need to be to partitioned matrix Y _cCcarry out inversion operation.In actual electrical network, consider that the scale of borderline region is generally less, be generally 4 to 6 nodes, therefore can substitute by the method for solving of linear equation the inversion operation of matrix.The variable quantity matrix of the matrix element that in one embodiment, in certainty equivalents posterior nodal point admittance matrix, borderline region is corresponding can comprise: the number of determining node in borderline region; In the situation that the number of node is less than predetermined threshold in borderline region, adopt the method that linear equation solves to calculate variable quantity matrix.Wherein, this predetermined threshold can value be 4 to 6, and concrete chooses according to actual needs, and the present invention is not construed as limiting this.That is, the mode solving by linear equation substitutes the mode of matrix inversion, can effectively reduce calculated amount like this when nodes is less.

IEEE39 node take below as example, analyze calculation of short-circuit current external network Equivalent Simplification method, as shown in Figure 7, is that the network structure of this IEEE39 node is divided schematic diagram.

As shown in Figure 7, borderline region comprises: tri-nodes of new14, new18 and new25, wherein, and reference capacity SB=100MVA, reference voltage V B=Vav=345kV, according to: the order computation Δ Y of new14, new18, new25 _bB, result of calculation as shown in Equation 11:

${\mathrm{\ΔY}}_{\mathrm{BB}}=\left[\begin{array}{ccc}-21.321760& -12.475537& -1.319840\\ -12.475537& -79.942309& -8.457436\\ -1.319840& -8.457436& -13.676654\end{array}\right]$ (formula 11)

Computing formula in above-mentioned steps S3, according to Δ Y in formula 11 _bBexploitation to obtain the reactance value of the element that newly increases on each boundary node and each newly-increased element as shown in table 2.

Table 2

Network using PSD-SCCP software before and after equivalent is carried out to three-phase shortcircuit current scanning, during calculating, do not consider load, line resistance, line charging power and the non-standard no-load voltage ratio of transformer, in the survey region of equivalent front and back, each node short-circuit current scanning result is as shown in table 3.

Table 3

Plant stand	Before equivalence/kA	After equivalent/kA	Difference/kA
				new1	9.783	9.783	0
new2	15.820	15.819	-0.001
				new3	12.428	12.426	-0.002

new4	11.331	11.330	-0.001
				new5	11.599	11.599	0
new6	11.950	11.950	0
				new7	9.511	9.511	0
new8	9.893	9.893	0
				new9	9.472	9.472	0
new10	11.047	11.047	0
				new11	10.770	10.770	0
new12	4.657	4.656	0
				new13	10.396	10.395	-0.001

By above-mentioned table 3, can be found out, before and after equivalent, only the short-circuit current value of node new2, new3, new4, new13 has small difference, further analysis can find out that these four nodes and borderline region exist directly contact, its short-circuit current error can be summed up as round-off error, while adding the reactance of newly-increased branch road and newly-increased equivalent generator in PSD-SCCP software, computational data is rounded up, thereby near causing there is small difference in the calculation of short-circuit current value of node.By the analysis result on IEEE39 node system, verified that method that the embodiment of the present invention provides can guarantee the computational accuracy of short-circuit current.

In the above embodiment of the present invention, provided in area power grid calculation of short-circuit current process, external electrical network is carried out to Equivalent Simplification processing, and after Equivalent Simplification the power network wiring form of reconstruct borderline region, being about to external network equivalence becomes the form of newly-increased circuit and newly-increased generator to be incorporated in borderline region, thereby form the electric network data that only retains survey region and borderline region, thereby significantly reduced the electrical network scale of calculation of short-circuit current, reduce the requirement to calculator memory and simulation software, improved operation of power networks analyst's work efficiency.

Based on same inventive concept, in the embodiment of the present invention, also provide a kind of area power grid Analysis of Short-Circuit Current device, as described in the following examples.Because the principle that area power grid Analysis of Short-Circuit Current device is dealt with problems is similar to area power grid Analysis of Short-Circuit Current method, therefore the enforcement of area power grid Analysis of Short-Circuit Current device can, referring to the enforcement of area power grid Analysis of Short-Circuit Current method, repeat part and repeat no more.Following used, term " unit " or " module " can realize the combination of software and/or the hardware of predetermined function.Although the described device of following examples is preferably realized with software, hardware, or the realization of the combination of software and hardware also may and be conceived.Fig. 8 is a kind of structured flowchart of the area power grid Analysis of Short-Circuit Current device of the embodiment of the present invention, as shown in Figure 8, comprising: module 801, Equivalent Simplification module 802 and analysis module 803 are divided in region, below this structure are described.

Module 801 is divided in region, for network system is carried out to region division: be survey region by the regional classification that needs analytical calculation short circuit current level, by there is the regional classification of directly contact with survey region, being borderline region, is perimeter by the regional classification except survey region and borderline region;

Equivalent Simplification module 802, for borderline region and perimeter are carried out to equivalent simplification, forms the borderline region after equivalence, the network system after the equivalence that obtains being comprised of the borderline region after survey region and equivalence;

Analysis module 803, for according to the network system after equivalence, the short circuit current level of analytical calculation survey region.

In one embodiment, above-mentioned Equivalent Simplification module 802 comprises: construction unit, for the bus admittance matrix of the sequential build network system according to perimeter, borderline region and survey region; Simplified element, for utilizing the part in Gaussian elimination method cancellation bus admittance matrix peripheral region, forms the equivalent posterior nodal point admittance matrix that only retains borderline region and survey region; Matrix determining unit, for the variable quantity matrix of matrix element corresponding to certainty equivalents posterior nodal point admittance matrix borderline region; Parameter determining unit, for the generator increasing according to the borderline region after described variable quantity matrix certainty equivalents, the connection branch road of increase, and the reactance parameter of generator increasing and the reactance parameter of the connection branch road of increase; Reconfiguration unit, for according to the generator increasing, the connection branch road of increase, the reactance parameter of the connection branch road of the reactance parameter of the generator of increase, increase and generator be connected connected mode between branch road and carry out network reconfiguration and form the network system after equivalence.

In one embodiment, described parameter determining unit comprises: first segment period is determined subelement, for determining the node number at the connection branch road two ends that increase; The first parameter is determined subelement, for getting the negative inverse of the element that variable quantity matrix is corresponding with the node number at two ends, as the reactance parameter of the connection branch road increasing.

In one embodiment, described parameter determining unit comprises: second section period is determined subelement, for determining the node number of the node being connected with the generator increasing; Cumulative unit, obtains resultant admittance for each element on this node number in the directly connected admittance that is connected branch road of the node of perimeter and this node number, variable quantity matrix is expert at as sum operation; The second parameter is determined subelement, for getting the inverse of resultant admittance as the reactance parameter of the generator increasing.

In one embodiment, matrix determining unit comprises: nodes is determined subelement, for determining the number of borderline region node; Computation subunit, in the situation that the number of borderline region node is less than predetermined threshold, adopts the method that linear equation solves to calculate variable quantity matrix.In concrete an enforcement, above-mentioned predetermined threshold can value be 6.

In another embodiment, also provide a kind of software, the technical scheme that this software is described for carrying out above-described embodiment and preferred implementation.

In another embodiment, also provide a kind of storage medium, stored above-mentioned software in this storage medium, this storage medium includes but not limited to: CD, floppy disk, hard disk, scratch pad memory etc.

From above description, can find out, the embodiment of the present invention has realized following technique effect: by the regional classification that needs analytical calculation short circuit current level in network system, be survey region, then by there is the regional classification of directly contact with survey region, be borderline region, by the regional classification except survey region and borderline region, it is perimeter, then by this network system Equivalent Simplification, be the network system that only comprises the borderline region after survey region and equivalence, finally by the short circuit current level of the network system analytical calculation survey region after equivalence, because no longer there is perimeter in the network system after Equivalent Simplification, therefore when analytical calculation short circuit current level, required data volume will obviously reduce.Efficiently solve by the way in prior art and be difficult to when guaranteeing calculation of short-circuit current precision, the technical matters of the data volume while reducing Analysis of Short-Circuit Current, reached and guaranteed on the basis of calculation of short-circuit current precision, the data volume while reducing Analysis of Short-Circuit Current and the technique effect of calculated amount.

Obviously, those skilled in the art should be understood that, each module of the above-mentioned embodiment of the present invention or each step can realize with general calculation element, they can concentrate on single calculation element, or be distributed on the network that a plurality of calculation elements form, alternatively, they can be realized with the executable program code of calculation element, thereby, they can be stored in memory storage and be carried out by calculation element, and in some cases, can carry out shown or described step with the order being different from herein, or they are made into respectively to each integrated circuit modules, or a plurality of modules in them or step are made into single integrated circuit module to be realized.Like this, the embodiment of the present invention is not restricted to any specific hardware and software combination.

The foregoing is only the preferred embodiments of the present invention, be not limited to the present invention, for a person skilled in the art, the embodiment of the present invention can have various modifications and variations.Within the spirit and principles in the present invention all, any modification of doing, be equal to replacement, improvement etc., within all should being included in protection scope of the present invention.

Claims (12)

1. an area power grid Analysis of Short-Circuit Current method, is characterized in that, comprising:

Network system is carried out to region division: by the regional classification that needs analytical calculation short circuit current level, be survey region, by there is the regional classification of directly contact with survey region, being borderline region, is perimeter by the regional classification except survey region and borderline region;

Borderline region and perimeter are carried out to equivalent simplification, form the borderline region after equivalence, the network system after the equivalence that obtains being formed by the borderline region after survey region and equivalence;

According to the network system after equivalence, the short circuit current level of analytical calculation survey region.

2. the method for claim 1, is characterized in that, borderline region and perimeter are carried out to equivalent simplification, forms the borderline region after equivalence, and the network system after the equivalence that obtains being comprised of the borderline region after survey region and equivalence, comprising:

According to the bus admittance matrix of the sequential build network system of perimeter, borderline region and survey region;

Utilize the part in Gaussian elimination method cancellation bus admittance matrix peripheral region, form the equivalent posterior nodal point admittance matrix that only retains borderline region and survey region;

The variable quantity matrix of the matrix element that in certainty equivalents posterior nodal point admittance matrix, borderline region is corresponding;

According to the generator increasing in the borderline region after described variable quantity matrix certainty equivalents, the connection branch road of increase, and the reactance parameter of generator increasing and the reactance parameter of the connection branch road of increase;

According to the connection branch road of the generator of the increase of determining, increase, the reactance parameter of the connection branch road of the reactance parameter of the generator of increase and increase carries out network reconfiguration and forms the network system after equivalence.

3. method as claimed in claim 2, is characterized in that, the reactance parameter according to the connection branch road increasing in the borderline region after described variable quantity matrix certainty equivalents, comprising:

Determine the node number at the connection branch road two ends that increase;

Get the negative inverse of element corresponding with the node number at two ends in variable quantity matrix, as the reactance parameter of the connection branch road increasing.

4. method as claimed in claim 2, is characterized in that, the reactance parameter according to the generator increasing in the borderline region after described variable quantity matrix certainty equivalents, comprising:

Determine the node number of the node being connected with the generator increasing;

Each element on this node number in the admittance that is connected branch road direct connected with the node of this node number in perimeter, variable quantity matrix is expert at obtains resultant admittance as sum operation;

Get the inverse of resultant admittance as the reactance parameter of the generator increasing.

5. method as claimed in claim 2, is characterized in that, the variable quantity matrix of the matrix element that in certainty equivalents posterior nodal point admittance matrix, borderline region is corresponding, comprising:

Determine the number of node in borderline region;

In the situation that the number of node is less than predetermined threshold in borderline region, adopt the method that linear equation solves to calculate variable quantity matrix.

6. as right, want the method as described in 5, it is characterized in that, described predetermined threshold is 6.

7. an area power grid Analysis of Short-Circuit Current device, is characterized in that, comprising:

Module is divided in region, for network system is carried out to region division: be survey region by the regional classification that needs analytical calculation short circuit current level, by there is the regional classification of directly contact with survey region, being borderline region, is perimeter by the regional classification except survey region and borderline region;

Equivalent Simplification module, for borderline region and perimeter are carried out to equivalent simplification, forms the borderline region after equivalence, the network system after the equivalence that obtains being comprised of the borderline region after survey region and equivalence;

Analysis module, for according to the network system after equivalence, the short circuit current level of analytical calculation survey region.

8. device as claimed in claim 7, is characterized in that, described Equivalent Simplification module comprises:

Construction unit, for the bus admittance matrix of the sequential build network system according to perimeter, borderline region and survey region;

Simplified element, for utilizing the part in Gaussian elimination method cancellation bus admittance matrix peripheral region, forms the equivalent posterior nodal point admittance matrix that only retains borderline region and survey region;

Matrix determining unit, for the variable quantity matrix of matrix element corresponding to certainty equivalents posterior nodal point admittance matrix borderline region;

Parameter determining unit, for the generator increasing according to the borderline region after described variable quantity matrix certainty equivalents, the connection branch road of increase, and the reactance parameter of generator increasing and the reactance parameter of the connection branch road of increase;

Reconfiguration unit, for according to the generator increasing, the connection branch road of increase, the reactance parameter of the reactance parameter of the generator of increase and the connection branch road that increases carries out network reconfiguration and forms the network system after equivalence.

9. device as claimed in claim 8, is characterized in that, described parameter determining unit comprises:

First segment period is determined subelement, for determining the node number at the connection branch road two ends that increase;

The first parameter is determined subelement, for getting the negative inverse of the element that variable quantity matrix is corresponding with the node number at two ends, as the reactance parameter of the connection branch road increasing.

10. device as claimed in claim 8, is characterized in that, described parameter determining unit comprises:

Second section period is determined subelement, for determining the node number of the node being connected with the generator increasing;

Cumulative unit, obtains resultant admittance for each element on this node number in the directly connected admittance that is connected branch road of the node of perimeter and this node number, variable quantity matrix is expert at as sum operation;

The second parameter is determined subelement, for getting the inverse of resultant admittance as the reactance parameter of the generator increasing.

11. devices as claimed in claim 8, is characterized in that, described matrix determining unit comprises:

Nodes is determined subelement, for determining the number of borderline region node;

Computation subunit, in the situation that the number of borderline region node is less than predetermined threshold, adopts the method that linear equation solves to calculate variable quantity matrix.

12. want the device as described in 11 as right, it is characterized in that, described predetermined threshold is 6.

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