CN103336866A - Processing method for negative resistance containing branch in electromagnetic transient simulation - Google Patents

Abstract

The invention discloses a processing method for a negative resistance containing branch in electromagnetic transient simulation. The processing method comprises the following steps: S1, acquiring an original parameter of the branch according to an original branch structure; S2, converting the negative resistance parameter containing branch into a T-shaped equivalent circuit model, wherein a series branch is a reactance branch, a parallel branch is a positive resistance branch, the parallel branch is grounded, and the values of reactance and positive resistance are calculated; S3, establishing a corresponding T-shaped equivalent circuit model in electromagnetic transient simulation software; and S4, verifying whether the established T-shaped equivalent circuit model can operate normally and meanwhile verifying the correctness of the model. The invention provides the processing method for the negative resistance parameter containing branch in the electromagnetic transient simulation. By using the method, the branch comprising the negative resistance parameter can be directly processed in the electromagnetic transient simulation software; and the method has clear physical meaning and a simple structure and is easy to popularize and use.

Description

The disposal route that contains the negative resistance branch road in a kind of electromagnetic transient simulation

Technical field

The present invention relates to the electric system simulation analysis technical field, particularly contain the disposal route of negative resistance parameter branch road in a kind of electromagnetic transient simulation.

Background technology

When the influencing each other of simulation study DC transmission system, FACTS element, distributed power source etc. and electrical network, need with the complicated dynamic response that uses electromagnetic transient simulation software modeling and emulation with the accurate model electric system.Because the electromagnetic transient simulation calculated amount is excessive, generally need to use the dynamic equivalent method to reduce the electrical network scale for the simulation modeling of large scale electric network.In the dynamic equivalent process, often there is the negative resistance parameter in equivalent the net in the newly-generated branch road, be embodied in the series arm of negative resistance and positive reactive, this is to be lost by the load in the equivalent time load transfer process to cause, and this negative resistance itself there is no the actual physical meaning.At present general electromagnetic transient simulation software (as PSCAD/EMTDC, RTDS etc.) all can't be handled the branch road that contains negative resistance because physical constraint is followed in strictness.

At present the disposal route that contains the negative resistance branch road there are two kinds: the one, in equivalent process, manually the negative resistance parameter adjustment is become 0, it is less that the active power that negative resistance is provided is assigned to the stable state trend variation that correspondence is adjusted after the node burden with power is adjusted with maintenance on circuit two end nodes simultaneously, but because it is more to contain the branch road of negative resistance parameter in the larger equivalence net of electrical network, this disposal route is comparatively loaded down with trivial details, and the process of adjusting is many to be guidance with the artificial experience, is theoretically unsound.The 2nd, in the electro-magnetic transient modeling process, directly resistance value is made as zero, namely contain the negative resistance branch road with the net resistance approximate representation.This disposal route not only lacks clear physical meaning, and can cause than mistake the circuit trend.Therefore need to propose to contain in a kind of electromagnetic transient simulation modeling the simple effective treating method of negative resistance branch road, show as the equivalent electrical circuit with actual physics meaning, this equivalent electrical circuit at first should be simple in structure, is easy to realize in electromagnetic transient simulation; Secondly can normally move, guarantee that simultaneously branch road trend resultant error is less.

Summary of the invention

The present invention proposes to contain in a kind of electromagnetic transient simulation the disposal route of negative resistance parameter branch road, adopts this method directly to handle the branch road that contains the negative resistance parameter in electromagnetic transient simulation software, and this method explicit physical meaning is simple in structure, is easy to promote the use of.

Purpose of the present invention is achieved through the following technical solutions:

Contain the disposal route of negative resistance branch road in the electromagnetic transient simulation of the present invention, comprise the steps:

S1, according to original line structure, obtain the initial parameter of this branch road;

S2, the branch road that will contain the negative resistance parameter are converted to T type equivalent-circuit model, and wherein series arm is reactance arm, and parallel branch is the positive resistance branch road, and parallel branch ground connection, calculate the value of reactance and positive resistance;

S3, in electromagnetic transient simulation software, set up corresponding T type equivalent-circuit model;

S4, the checking T type equivalent-circuit model of building can normally move the accuracy of simultaneous verification model.

Preferably, among the described step S1, according to original line structure, the initial parameter that obtains this branch road comprises: negative resistance-R (p.u.), reactance X (p.u.), reference voltage V _B(kV), reference capacity S _B(MWA), reference frequency f(Hz).

Preferably, the branch road that will contain the negative resistance parameter among the described step S2 is converted to T type equivalent-circuit model, and wherein series arm is reactance arm, and parallel branch is the positive resistance branch road, and parallel branch ground connection, calculates the perunit value of reactance and positive resistance;

21) T type series arm reactance X ₁And X ₂Computing formula be:

${\mathrm{<figure-callout\; id="1"\; label="X"\; filenames="HDA00003419603700011.png,HDA00003419603700021.png"\; state="\{\{state\}\}">X</figure-callout>}}_1={\mathrm{<figure-callout\; id="2"\; label="X"\; filenames="HDA00003419603700011.png,HDA00003419603700012.png"\; state="\{\{state\}\}">X</figure-callout>}}_2=\frac{1}{2}X---\left(1\right)$

22) T type ground connection branch road in parallel resistance R _kComputing formula be:

$R_k=\frac{{\mathrm{<figure-callout\; id="1"\; label="X"\; filenames="HDA00003419603700011.png,HDA00003419603700021.png"\; state="\{\{state\}\}">X</figure-callout>}}_1\&CenterDot;X_2}{R}=\frac{X^2}{4R}---\left(2\right).$

Preferably, among the step S1, the flow data of the initial parameter of circuit after by power system dynamic equivalence obtains or specifies according to the particular studies purpose.

Preferably, the equivalent model among the step S3 is not owing to contain negative resistance, and the resistance and the inductor models that directly use electromagnetic transient simulation software to carry in the model bank are set up according to the T type equivalent electrical circuit among the step S2.

Preferably, the checking T type equivalent-circuit model of building can normally move by the compiling of electromagnetic transient simulation software among the step S4, output trend result comprises node voltage and line power, and by with dynamic equivalent after the original branch road trend result contrast that obtains of flow data with the accuracy of verification model.

The present invention has following advantage and effect with respect to prior art:

1, the present invention proposes to contain in a kind of electromagnetic transient simulation the disposal route of negative resistance parameter branch road, adopt this method can directly in electromagnetic transient simulation software, handle the branch road that contains the negative resistance parameter, this method explicit physical meaning, simple in structure, be easy to promote the use of.

2, the present invention a kind ofly solves this problem with the circuit that contains the branch road equivalence of negative resistance by setting up because each element in the equivalent electrical circuit all has the actual physics meaning, electromagnetic transient simulation software can simulation analysis should the equivalence circuit.

3, the T type equivalent electrical circuit of setting up among the present invention has clear physical meaning, can prove its rationality by the equivalence conversion of circuit, and the trend resultant error is less.According to the Y/ △ transformation theory in the classical circuit, can be converted to △ type circuit shown in Figure 3 in the T type equivalent electrical circuit of accompanying drawing 2, Fig. 4 is the π type equivalent electrical circuit of Fig. 3 △ type circuit correspondence.

The transfer impedance Z of 12 of branch roads among Fig. 4 ₁₂For:

$Z_{12}=\mathrm{<figure-callout\; id="1"\; label="j\; X"\; filenames="HDA00003419603700011.png,HDA00003419603700021.png"\; state="\{\{state\}\}">j</figure-callout>}{X}_{}{}_1+\mathrm{<figure-callout\; id="2"\; label="j\; X"\; filenames="HDA00003419603700011.png,HDA00003419603700012.png"\; state="\{\{state\}\}">j</figure-callout>}{X}_{}{}_2+\frac{j{X}_{1}j{X}_2}{R_k}=-\frac{X_1{X}_2}{R_k}+j({\mathrm{<figure-callout\; id="1"\; label="X"\; filenames="HDA00003419603700011.png,HDA00003419603700021.png"\; state="\{\{state\}\}">X</figure-callout>}}_1+X_2)$

Because ${\mathrm{<figure-callout\; id="1"\; label="X"\; filenames="HDA00003419603700011.png,HDA00003419603700021.png"\; state="\{\{state\}\}">X</figure-callout>}}_1=X_2=\frac{1}{2}X,R_k=\frac{X_1{X}_2}{R}=\frac{X^2}{4R},$

Z then ₁₂=-R+jX=Z, namely the size of 12 transfer impedances of branch road is consistent with the impedance of former negative resistance branch road.

The transfer impedance that branch road is 13 is:

Wherein, $\left|Z_{13}\right|=\sqrt{{\left(\frac{{\mathrm{<figure-callout\; id="2"\; label="X"\; filenames="HDA00003419603700011.png,HDA00003419603700012.png"\; state="\{\{state\}\}">X</figure-callout>}}^2}{2R}\right)}^2+{\left(\frac{X}{2}\right)}^2}=\frac{X}{2R}\sqrt{R^2+{\mathrm{<figure-callout\; id="2"\; label="X"\; filenames="HDA00003419603700011.png,HDA00003419603700012.png"\; state="\{\{state\}\}">X</figure-callout>}}^2},$

Because 0＜R＜＜X, so | Z ₁₃| → ∞, namely branch road 13 is equivalent to ground connection branch road that resistance value is bigger in parallel, and is less for the trend influence of circuit, can be similar to and ignore; In like manner the transfer impedance of 23 of branch roads also can be ignored for the influence of circuit trend.

Description of drawings

Fig. 1 is the structural representation of the original branch road of the present invention;

Fig. 2 is the T type equivalent-circuit model synoptic diagram of the correspondence set up in the electromagnetic transient simulation software;

Fig. 3 is the △ type circuit diagram after the T type equivalent-circuit model of Fig. 2 passes through Y/ △ conversion;

Fig. 4 is the π type equivalent circuit diagram of Fig. 3 circuit correspondence;

Fig. 5 is process flow diagram of the present invention.

Embodiment

The present invention is described in further detail below in conjunction with embodiment and accompanying drawing, but embodiments of the present invention are not limited thereto.

Embodiment

The present invention is the disposal route that contains negative resistance parameter branch road in a kind of electromagnetic transient simulation, this method is converted into the T type equivalent-circuit model that contains reactance series arm and positive resistance parallel branch by the branch road that will contain the negative resistance parameter, then in electromagnetic transient simulation software, build this T type equivalent electrical circuit, successfully realize containing the electromagnetic transient simulation of negative resistance parameter branch road.

As shown in Figure 5, technical scheme of the present invention is:

A kind of implementation method that contains the negative resistance branch road in electromagnetic transient simulation may further comprise the steps:

1) establish original line structure as shown in Figure 1, obtain the initial parameter of this branch road, wherein R and X represent resistance and the reactance of branch road respectively, and-R represents that the branch road resistor symbols is for negative;

2) branch road that will contain the negative resistance parameter is converted to T type equivalent-circuit model, as shown in Figure 2, and X wherein ₁, X ₂Be series reactance branch road, R _kBe stake resistance branch road in parallel, wherein series arm is reactance arm, and parallel branch is the positive resistance branch road, and parallel branch ground connection, calculates the value of reactance and positive resistance;

3) in electromagnetic transient simulation software, set up corresponding T type equivalent-circuit model according to circuit diagram shown in Figure 2;

4) the checking T type equivalent-circuit model of building can normally move, and calculates the trend error according to the trend result.

The parameter of the original branch road of described step 1) comprises: negative resistance-R=0.00001 (p.u.), reactance X=0.04 (p.u.), reference voltage V _B=525(kV), reference capacity S _B=100 (MWA), reference frequency f=50(Hz).

Described step 2) parameter of the T type equivalent-circuit model after the conversion comprises reactance X ₁, X ₂, resistance R _k, and satisfy X ₁0, X ₂0, R _k0;

Described step 2) reactance X ₁, X ₂With positive resistance R _kComputing method as follows:

21) T type series arm reactance X ₁And X ₂Computing formula be:

${\mathrm{<figure-callout\; id="1"\; label="X"\; filenames="HDA00003419603700011.png,HDA00003419603700021.png"\; state="\{\{state\}\}">X</figure-callout>}}_1=X_2=\frac{1}{2}X=0.02---\left(1\right)$

22) T type ground connection branch road in parallel resistance R _kComputing formula be:

$R_k=\frac{{\mathrm{<figure-callout\; id="1"\; label="X"\; filenames="HDA00003419603700011.png,HDA00003419603700021.png"\; state="\{\{state\}\}">X</figure-callout>}}_1\&CenterDot;X_2}{R}=\frac{X^2}{4R}=40---\left(2\right)$

Described step 3) is according to circuit diagram and step 2 shown in Figure 2) result of calculation in electromagnetic transient simulation software, set up corresponding T type equivalent-circuit model;

Described step 4) empirical tests is built T type equivalent-circuit model and can normally be moved, and contrast trend resultant error is:

Fig. 2 to deserved T type equivalent electrical circuit and the corresponding original branch road of Fig. 1 in the voltage magnitude error at node 1 place for (to establish voltage and the known V of being respectively of power at node 2 places ₂=1.0, S ₂=1.0+j1.0):

$\mathrm{\&Delta;V}\%=\frac{{\mathrm{<figure-callout\; id="1"\; label="V"\; filenames="HDA00003419603700011.png,HDA00003419603700021.png"\; state="\{\{state\}\}">V</figure-callout>}}_1^{\&prime;}-V_1}{{\mathrm{<figure-callout\; id="1"\; label="V"\; filenames="HDA00003419603700011.png,HDA00003419603700021.png"\; state="\{\{state\}\}">V</figure-callout>}}_1}\&times;100\%=\frac{1.040778-1.040759}{1.040759}\&times;100\%=0.001834\%;$

Meritorious and idle error is respectively:

$\mathrm{\&Delta;P}\%=\frac{{\mathrm{<figure-callout\; id="1"\; label="P"\; filenames="HDA00003419603700011.png,HDA00003419603700021.png"\; state="\{\{state\}\}">P</figure-callout>}}_1^{\&prime;}-P_1}{{\mathrm{<figure-callout\; id="1"\; label="P"\; filenames="HDA00003419603700011.png,HDA00003419603700021.png"\; state="\{\{state\}\}">P</figure-callout>}}_1}\&times;100\%=\frac{1.02602-0.99998}{0.99998}\&times;100\%=2.604051\%;$

$\mathrm{\&Delta;Q}\%=\frac{{\mathrm{<figure-callout\; id="1"\; label="Q"\; filenames="HDA00003419603700011.png,HDA00003419603700021.png"\; state="\{\{state\}\}">Q</figure-callout>}}_1^{\&prime;}-Q_1}{{\mathrm{<figure-callout\; id="1"\; label="Q"\; filenames="HDA00003419603700011.png,HDA00003419603700021.png"\; state="\{\{state\}\}">Q</figure-callout>}}_1}\&times;100\%=\frac{1.080999-1.08}{1.08}\&times;100\%=0.092545\%;$

As seen scope of all allowing in engineering calculation of voltage error, the meritorious idle error of sum of errors and so on, thus validity of the present invention verified by this embodiment.

Above-described embodiment is preferred implementation of the present invention; but embodiments of the present invention are not restricted to the described embodiments; other any do not deviate from change, the modification done under spiritual essence of the present invention and the principle, substitutes, combination, simplify; all should be the substitute mode of equivalence, be included within protection scope of the present invention.

Claims (6)

1. contain the disposal route of negative resistance branch road in the electromagnetic transient simulation, it is characterized in that, comprise the steps:

S1, according to original line structure, obtain the initial parameter of this branch road;

S2, the branch road that will contain the negative resistance parameter are converted to T type equivalent-circuit model, and wherein series arm is reactance arm, and parallel branch is the positive resistance branch road, and parallel branch ground connection, calculate the value of reactance and positive resistance;

S3, in electromagnetic transient simulation software, set up corresponding T type equivalent-circuit model;

S4, the checking T type equivalent-circuit model of building can normally move the accuracy of simultaneous verification model.

2. contain the disposal route of negative resistance branch road in the electromagnetic transient simulation according to claim 1, it is characterized in that, among the described step S1, according to original line structure, the initial parameter that obtains this branch road comprises: negative resistance-R (p.u.), reactance X (p.u.), reference voltage V _B(kV), reference capacity S _B(MWA), reference frequency f(Hz).

3. according to the disposal route that contains the negative resistance branch road in the described electromagnetic transient simulation of claim 1, it is characterized in that, the branch road that will contain the negative resistance parameter among the described step S2 is converted to T type equivalent-circuit model, wherein series arm is reactance arm, parallel branch is the positive resistance branch road, and parallel branch ground connection, the perunit value of calculating reactance and positive resistance;

21) T type series arm reactance X ₁And X ₂Computing formula be:

$X_1=X_2=\frac{1}{2}X---\left(1\right)$

22) T type ground connection branch road in parallel resistance R _kComputing formula be:

$R_k=\frac{X_1\&CenterDot;X_2}{R}=\frac{X^2}{4R}---\left(2\right).$

4. according to the disposal route that contains the negative resistance branch road in the described electromagnetic transient simulation of claim 1, it is characterized in that among the step S1, the flow data of the initial parameter of circuit after by power system dynamic equivalence obtains or specify according to the particular studies purpose.

5. according to the disposal route that contains the negative resistance branch road in the described electromagnetic transient simulation of claim 1, it is characterized in that, equivalent model among the step S3 is not owing to contain negative resistance, and the resistance and the inductor models that directly use electromagnetic transient simulation software to carry in the model bank are set up according to the T type equivalent electrical circuit among the step S2.

6. according to the disposal route that contains the negative resistance branch road in the described electromagnetic transient simulation of claim 1, it is characterized in that, the checking T type equivalent-circuit model of building can normally move by the compiling of electromagnetic transient simulation software among the step S4, output trend result comprises node voltage and line power, and by with dynamic equivalent after the original branch road trend result contrast that obtains of flow data with the accuracy of verification model.

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