CN102495327A - Detection method and device for design of grounding grid of substation - Google Patents

Abstract

The invention provides a detection method for the design of a grounding grid of a substation, which includes the steps: building a boundary element model of the grounding grid; obtaining impedance characteristics of a grounding grid conductor; computing the grounding resistance of the grounding grid according to the impedance characteristics of the grounding grid conductor and the built boundary element model; obtaining total fault current and current divider coefficient of the grounding grid; determining the quantity of potential rise caused by the grounding grid according to the total fault current, the current divider coefficient and the grounding resistance of the grounding grid; and adjusting equipment parameters corresponding to the grounding grid according to the quantity of potential rise caused by the grounding grid. The invention further provides a detection device for the design of the grounding grid of the substation, which can be used for increasing the accurate rate of the grounding resistance of the grounding grid of the substation, increasing the accurate rate of the quantity of potential rise caused by the grounding grid and ensuring safety of staff and normal power transmission.

Description

A kind of grounding net of transformer substation design detection method and device

Technical field

The present invention relates to the transformer station of electric system, be specifically related to a kind of detection method and device of grounding net of transformer substation design.

Background technology

Grounded screen substation safety in service play a part very important; Be not merely various electrical equipments in the station a public reference ground is provided; Drain fault current in the time of can also breaking down in system and reduce the earth potential liter of transformer station, thereby guarantee stand interior staff's the personal safety and the normal operation of various electrical equipments.

An important goal of grounded screen design is that the maximum potential of control grounded screen raises.Wherein, the current potential that causes of grounded screen raises: V=RI; R representes stake resistance, and I representes into the earth fault electric current, and I=Ie * (1-Ke), Ie is the total failare electric current, and Ke is a diverting coefficient.Domestic employing steel grounded screen, the resistivity and the magnetic permeability of steel are higher, and grounded screen not equipotential problem is comparatively serious.The passing grounded screen designing and calculating instrument that corresponding geology and geomorphology situation is not arranged, under the power frequency fault current, the grounding grid design of transformer station is directly applied mechanically passing equipotential model, and the stake resistance error that calculates is bigger; When electric system generation earth fault, go into the current potential that on earthed system, produces of alternating current on ground, the component with the electric current homophase is not only arranged, also have the component with the earth current quadrature, i.e. perceptual part in the ground connection parameter.In the electrical grounding design, ignored perceptual weight, it is on the low side more that the grounded screen maximum potential of calculating is raise, and threatens staff's life safety, electrical equipment work undesired, and influence is transmission of electricity normally.

Summary of the invention

The objective of the invention is to propose a kind of detection method of grounding net of transformer substation design, can improve the accuracy of the stake resistance of grounding net of transformer substation, the accuracy of the potential rise a large amount that raising grounded screen causes guarantees staff's safety and transmission of electricity normally.

Based on above-mentioned purpose, the scheme of employing:

A kind of detection method of grounding net of transformer substation design comprises step:

Set up the boundary element model of grounded screen;

Obtain the impedance operator of grounded screen conductor;

According to the impedance operator of said grounded screen conductor and the boundary element model of foundation, calculate the stake resistance of grounded screen;

Obtain the total failare electric current and the diverting coefficient of grounded screen;

According to the total failare electric current of said grounded screen, said diverting coefficient and said stake resistance, confirm the potential rise a large amount that grounded screen causes;

Potential rise a large amount according to said grounded screen causes is regulated grounded screen corresponding equipment parameter.

The present invention sets up the boundary element model of grounded screen earlier, obtains the impedance operator of grounded screen conductor then, utilizes its impedance operator and boundary element model to carry out simultaneous solution, is grounded the not correct calculation of the Resistance of Grounding Grids under the equipotential situation of net; Obtain the total failare electric current and the diverting coefficient of grounded screen again; Stake resistance calculating in conjunction with calculating obtains the potential rise a large amount that the higher grounded screen of accuracy rate causes; Regulate grounded screen corresponding equipment parameter according to this potential rise a large amount, safeguard work personnel's life safety ensures normally transmission of electricity.

The present invention also aims to propose a kind of pick-up unit of grounding net of transformer substation design, can improve the accuracy of the stake resistance of grounding net of transformer substation, the accuracy of the potential rise a large amount that raising grounded screen causes guarantees staff's safety and transmission of electricity normally.

Based on above-mentioned purpose, the scheme of employing:

A kind of pick-up unit of grounding net of transformer substation design comprises:

The modelling unit is used to set up the boundary element model of grounded screen;

First acquiring unit is used to obtain the impedance operator of grounded screen conductor;

First computing unit is used for according to the impedance operator of said grounded screen conductor and the boundary element model of foundation, calculates the stake resistance of grounded screen;

Second acquisition unit is used to obtain the total failare electric current and the diverting coefficient of grounded screen;

Second computing unit is used for the total failare electric current according to said grounded screen, said diverting coefficient and said stake resistance, confirms the potential rise a large amount that grounded screen causes;

Regulon, the potential rise a large amount that is used for causing according to said grounded screen is regulated grounded screen corresponding equipment parameter.

Apparatus of the present invention are set up the boundary element model of grounded screen through the modelling unit, obtain the impedance operator of grounded screen conductor then through first acquiring unit; First computing unit utilizes its impedance operator and boundary element model to carry out simultaneous solution, is grounded the not correct calculation of the Resistance of Grounding Grids under the equipotential situation of net; Obtain the total failare electric current and the diverting coefficient of grounded screen again through second acquisition unit; The stake resistance calculating that second computing unit combines to calculate obtains the potential rise a large amount that the higher grounded screen of accuracy rate causes; Regulon is regulated grounded screen corresponding equipment parameter according to this potential rise a large amount; Safeguard work personnel's life safety ensures normally transmission of electricity.

Description of drawings

Fig. 1 is a process flow diagram of the inventive method;

Fig. 2 is a scale coefficient iteration subdivision method principle schematic;

Fig. 3 is a structural representation of apparatus of the present invention.

Embodiment

For ease of understanding the present invention, will combine accompanying drawing to set forth below.

Please refer to Fig. 1, the present invention proposes a kind of detection method of grounding net of transformer substation design, comprises step:

101, set up the grounded screen boundary model;

102, obtain grounded screen Conductor Impedance characteristic;

103, calculate stake resistance according to boundary model and impedance operator;

According to the impedance operator of grounded screen conductor and the boundary element model of foundation, calculate the stake resistance of grounded screen.

Concrete: boundary element electric density η _iSatisfy following condition:

${\mathrm{\η}}_i=-\frac{1}{2\mathrm{\π}}\frac{{\mathrm{\ρ}}_{\mathrm{bi}}-{\mathrm{\ρ}}_{\mathrm{fi}}}{{\mathrm{\ρ}}_{\mathrm{bi}}+{\mathrm{\ρ}}_{\mathrm{fi}}}[{\mathrm{\η}}_i{\∫}_{s_i}\frac{{\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_i^{\′}}{{|{\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_i^{\′}|}^3}\·{\hat{n}}_i\mathrm{ds}$

$+\underset{j=1,j\≠i}{\overset{m}{\mathrm{\Σ}}}{\mathrm{\η}}_j{\∫}_{s_j}(\frac{{\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_j}{{|{\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_j|}^3}+\frac{{\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_j^{\′}}{{|{\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_j^{\′}|}^3})\·{\hat{n}}_i\mathrm{ds}+\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\ϵ}}_j{\∫}_{L_j}(\frac{{\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_j}{{|{\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_j|}^3}+\frac{{\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_j^{\′}}{{|{\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_j^{\′}|}^3})\·{\hat{n}}_i\mathrm{dL}]---\left(1\right)$

${\mathrm{\η}}_i=-{\mathrm{\α}}_i[{\mathrm{\η}}_i{\∫}_{s_i}\frac{{\stackrel{\→}{r}}_{\mathrm{ii}}^{\′}}{{\left|{\stackrel{\→}{r}}_{\mathrm{ii}}^{\′}\right|}^3}\·{\hat{n}}_i\mathrm{ds}+\underset{j=1,j\≠i}{\overset{m}{\mathrm{\Σ}}}{\mathrm{\η}}_j{\∫}_{s_j}(\frac{{\stackrel{\→}{r}}_{\mathrm{ij}}}{{\left|{\stackrel{\→}{r}}_{\mathrm{ij}}\right|}^3}+\frac{{\stackrel{\→}{r}}_{\mathrm{ij}}^{\′}}{{\left|{\stackrel{\→}{r}}_{\mathrm{ij}}^{\′}\right|}^3})\·{\hat{n}}_i\mathrm{ds}+\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\ϵ}}_j{\∫}_{L_j}(\frac{{\stackrel{\→}{r}}_{\mathrm{ij}}}{{\left|{\stackrel{\→}{r}}_{\mathrm{ij}}\right|}^3}+\frac{{\stackrel{\→}{r}}_{\mathrm{ij}}^{\′}}{{\left|r_{\mathrm{ij}}^{\′}\right|}^3})\·{\hat{n}}_i\mathrm{dL}]---\left(2\right)$

Wherein, ${\mathrm{\α}}_i=\frac{1}{2\mathrm{\π}}\frac{{\mathrm{\ρ}}_{\mathrm{bi}}-{\mathrm{\ρ}}_{\mathrm{fi}}}{{\mathrm{\ρ}}_{\mathrm{bi}}+{\mathrm{\ρ}}_{\mathrm{fi}}},$ ${\stackrel{\→}{r}}_{\mathrm{ij}}={\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_j,$ ${\stackrel{\→}{r}}_{\mathrm{ij}}^{\′}={\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_i^{\′},$ ${\mathrm{\ϵ}}_i=\frac{{\mathrm{\ϵ}}_0{\mathrm{\ρ}}_i{I}_i}{L_i},$ I _iBe the earth current of i section conductor, r is a resistance, and ρ is a resistivity, and L is a conductor length, and s is a conductor cross-sectional area, and η is a boundary element electric density, and ε is a specific inductive capacity, and n is the boundary element number;

Formula (2) is write as matrix form:

Aη′+BI＝0 (3)

Wherein, ${\mathrm{\η}}^{\′}=\frac{\mathrm{\η}}{{\mathrm{\ϵ}}_0},$ $A_{i,i}=1+{\mathrm{\α}}_i{\∫}_{s_i}\frac{{\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_i^{\′}}{{|{\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_i^{\′}|}^3}\·{\hat{n}}_i\mathrm{ds},$ $A_{i,j}={\mathrm{\α}}_i{\∫}_{s_j}(\frac{{\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_j}{{|{\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_j|}^3}+\frac{{\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_j^{\′}}{{|{\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_j^{\′}|}^3})\·{\hat{n}}_i\mathrm{ds}(i\≠j),$ $B_{i,j}={\mathrm{\α}}_i\frac{{\mathrm{\ρ}}_i}{L_i}{\∫}_{L_j}(\frac{{\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_j}{{|{\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_j|}^3}+\frac{{\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_j^{\′}}{{|{\stackrel{\→}{r}}_i-{\stackrel{\→}{r}}_j^{\′}|}^3})\·{\hat{n}}_i\mathrm{dL}.$

Conductor current potential U _iSatisfy following condition:

$U_i=\frac{1}{4\mathrm{\π}{\mathrm{\ϵ}}_0}[\underset{j=1}{\overset{m}{\mathrm{\Σ}}}{\mathrm{\η}}_j{\∫}_{s_j}(\frac{1}{\left|{\stackrel{\→}{r}}_{\mathrm{ij}}\right|}+\frac{1}{\left|{\stackrel{\→}{r}}_{\mathrm{ij}}^{\′}\right|})\mathrm{ds}+\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\ϵ}}_j{\∫}_{L_j}(\frac{1}{\left|{\stackrel{\→}{r}}_{\mathrm{ij}}\right|}+\frac{1}{\left|{\stackrel{\→}{r}}_{\mathrm{ij}}^{\′}\right|})\mathrm{dL}]---\left(4\right)$

Formula (4) is write as matrix form:

U＝Cη′+DI (5)

Wherein: $C_{i,j}=\frac{1}{4\mathrm{\π}}{\∫}_{s_j}(\frac{1}{\left|{\stackrel{\→}{r}}_{\mathrm{ij}}\right|}+\frac{1}{\left|{\stackrel{\→}{r}}_{\mathrm{ij}}^{\′}\right|})\mathrm{ds},$ $D_{i,j}=\frac{1}{4\mathrm{\π}}\frac{{\mathrm{\ρ}}_i}{L_i}{\∫}_{L_j}(\frac{1}{\left|{\stackrel{\→}{r}}_{\mathrm{ij}}\right|}+\frac{1}{\left|{\stackrel{\→}{r}}_{\mathrm{ij}}^{\′}\right|})\mathrm{dL}.$

Have by the ground connection theory:

U＝KV (6)

F＝K ^tI+A ^tGAV (7)

Separated:

F＝[K ^t(D-CA ^-1B) ^-1K+A ^tGA]V (8)

Wherein, U represents conductor current potential matrix; V representation node current potential matrix; K represents incidence matrix; F representation node injection current column vector;

Can obtain grounding resistance by above-mentioned formula; Stake resistance calculating value equals maximum node voltage divided by the node injection current.

104, obtain total failare electric current and diverting coefficient;

Obtain the total failare electric current and the diverting coefficient of grounded screen.

105, calculate the potential rise a large amount according to total failare electric current, diverting coefficient and stake resistance;

According to total failare electric current, diverting coefficient and the stake resistance of grounded screen, calculate the potential rise a large amount that grounded screen causes.

106, regulate the grounded screen device parameter according to the potential rise a large amount.

Potential rise a large amount according to grounded screen causes is regulated grounded screen corresponding equipment parameter.

The present invention sets up the boundary element model of grounded screen earlier, obtains the impedance operator of grounded screen conductor then, utilizes its impedance operator and boundary element model to carry out simultaneous solution, is grounded the not correct calculation of the Resistance of Grounding Grids under the equipotential situation of net; Obtain the total failare electric current and the diverting coefficient of grounded screen again; Stake resistance calculating in conjunction with calculating obtains the potential rise a large amount that the higher grounded screen of accuracy rate causes; Regulate grounded screen corresponding equipment parameter according to this potential rise a large amount, safeguard work personnel's life safety ensures normally transmission of electricity.

Because the area of the covering of transmission line of electricity is with a varied topography, for example coastal knob; Its substation grounding number of conductor is numerous and the overlay area is big, and space distribution is irregular, adds that geological condition is very complicated, has caused very difficulty of boundary element subdivision.Adopt at present usually the method for manual specified boundary subdivision form to carry out, subdivision number and the subdivision ratio of promptly manually importing each concrete border is to satisfy near the enough dense requirement in border the conductor.This method shortcoming is fairly obvious: on the one hand, often carry out according to my experience through manual specified boundary subdivision form, need repeatedly adjust the subdivision parameter usually and just can obtain the correct calculation result, thereby be theoretically unsound; Coastal in addition knob transformer station border is numerous, the manual methods inefficiency.Can do following the improvement to the foregoing description for this reason:

When setting up the boundary element model of grounded screen, utilize the spatial relationship on grounded screen conductor and border to be grounded the self-adaptation subdivision of conductor, set up the boundary element model of ultra-large ground connection entoilage according to the conductor behind the subdivision (boundary element).Its concrete steps are following:

Please refer to Fig. 2, have a quadrilateral original boundaries S and point source P, e ₁And e ₂For two yardsticks of S, get scale coefficient k, d is the vertical range of P and S, and agreement below doing:

1. if d>=ke ₁, d>=ke ₂Complete is that then S does not all segment 2 parts on two dimension, and this moment, S was divided into 4 parts;

2. if d>=ke ₁, d>=ke ₂Have one to be not, for denying that the person segments 2 parts on dimension, this moment, S was divided into 2 parts;

3. if d>=ke ₁, d>=ke ₂Be very, then S need not further subdivision;

4. if the situation of S through segmentation occur, the S after the segmentation replaces former S to make iteration, satisfies d>=ke until all borders ₁, d>=ke ₂

Adopt the ultra-large boundary element model of above-mentioned foundation, promoted the boundary element number that uses during ground connection is calculated greatly.Be limited to 7500 on the present most widely used external software cd EGS boundary element; And the upper limit of software for calculation of the present invention can reach 40000; Thereby can consider complicated geological condition, and find the solution irregular soil problem with grounding, be applicable to the substation grounding calculating of coastal knob.

Because the number of boundary element is numerous, the speed of model solution is slow, and computation model is found the solution with the form of matrix algorithms.

Can use parallel triangle (LU) decomposition method for raising speed finds the solution; Parallel LU factorization adopts parallel Du Liteer to decompose the product that the coefficient matrices A of full rank equation is decomposed into upper triangular matrix U and following triangle battle array L; And deposit in original matrix A with compact form; Mode with back substitution when solving an equation is carried out; Have save memory, computing velocity is fast, advantages such as better numerical value stability.

At transformer station's diverting coefficient is an important parameter must considering when analyzing earthed system safety.China is in design in the past, and diverting coefficient often adopts simplifies the method for calculating or estimating, has ignored the influence of several factors like this, often causes bigger error.For head it off, can do following the improvement to obtaining of diverting coefficient:

When obtaining the diverting coefficient of grounded screen, confirm the structural parameters of circuit in the electrical network, the structural parameters of transformer, the ground connection parameter of grounding net of transformer substation earlier;

According to the method for operation of electrical network, carry out the structural parameters of circuit, transformer, grounding net of transformer substation the modeling of phase component;

According to the phase component model of the circuit of cyclic current method and foundation, transformer, grounding net of transformer substation, the fault current of finding the solution electrical network distributes, thereby obtains diverting coefficient by definition.

Introduce apparatus of the present invention below, please be with reference to figure 3, a kind of pick-up unit of grounding net of transformer substation design:

Modelling unit T1 is used to set up the boundary element model of grounded screen;

The first acquiring unit T2 is used to obtain the impedance operator of grounded screen conductor;

The first computing unit T3 is used for according to the impedance operator of grounded screen conductor and the boundary element model of foundation, calculates the stake resistance of grounded screen;

Second acquisition unit T4 is used to obtain the total failare electric current and the diverting coefficient of grounded screen;

The second computing unit T5 is used for total failare electric current, diverting coefficient and stake resistance according to grounded screen, confirms the potential rise a large amount that grounded screen causes;

Regulon T6, the potential rise a large amount that is used for causing according to grounded screen is regulated grounded screen corresponding equipment parameter.

Apparatus of the present invention are set up the boundary element model of grounded screen through the modelling unit, obtain the impedance operator of grounded screen conductor then through first acquiring unit; First computing unit utilizes its impedance operator and boundary element model to carry out simultaneous solution, is grounded the not correct calculation of the Resistance of Grounding Grids under the equipotential situation of net; Obtain the total failare electric current and the diverting coefficient of grounded screen again through second acquisition unit; The stake resistance calculating that second computing unit combines to calculate obtains the potential rise a large amount that the higher grounded screen of accuracy rate causes; Regulon is regulated grounded screen corresponding equipment parameter according to this potential rise a large amount; Safeguard work personnel's life safety ensures normally transmission of electricity.

Because the covering of transmission line of electricity is regional with a varied topography, for example coastal knob; Its substation grounding number of conductor is numerous and the overlay area is big, and space distribution is irregular, adds that geological condition is very complicated, has caused very difficulty of boundary element subdivision.Usually adopt the method for manual specified boundary subdivision form to carry out at present, be theoretically unsound, the diverting coefficient that obtains is inaccurate, and the manual methods inefficiency.Can do following the improvement to the foregoing description for this reason:

Modelling unit T1 utilizes the spatial relationship on grounded screen conductor and border to be grounded the self-adaptation subdivision of conductor when setting up the boundary element model of grounded screen, sets up the boundary element model of ultra-large ground connection entoilage according to the boundary element behind the subdivision.

In order to improve arithmetic speed, the first computing unit T3 adopts matrix algorithms to calculate the stake resistance of grounded screen; Adopt parallel LU decomposition algorithm to calculate stake resistance.

At transformer station's diverting coefficient is an important parameter must considering when analyzing earthed system safety.China is in design in the past, and diverting coefficient often adopts simplifies the method for calculating or estimating, has ignored the influence of several factors like this, often causes bigger error.For head it off, can do following the improvement to obtaining of diverting coefficient:

Second acquisition unit T4 sets up the structural parameters of the force device of grounded screen when obtaining the diverting coefficient of grounded screen;

According to the method for operation of electrical network, carry out the structural parameters of circuit, transformer, grounding net of transformer substation the modeling of phase component; According to the phase component model of the circuit of cyclic current method and foundation, transformer, grounding net of transformer substation, the fault current of finding the solution electrical network distributes, thereby obtains diverting coefficient by definition.

Utilize method of the present invention, can also detect the detection of other ground connection parameters in the grounded screen design, for example: earth mat self Potential distribution, surface potential distribution, contact electricity, step voltage etc.

Above embodiment of the present invention does not constitute the qualification to protection domain of the present invention.Any modification of within spirit of the present invention and principle, being done, be equal to replacement and improvement etc., all should be included within the claim protection domain of the present invention.

Claims (10)

1. the detection method of a grounding net of transformer substation design is characterized in that, comprises step:

Set up the boundary element model of grounded screen;

Obtain the impedance operator of grounded screen conductor;

According to the impedance operator of said grounded screen conductor and the boundary element model of foundation, calculate the stake resistance of grounded screen;

Obtain the total failare electric current and the diverting coefficient of grounded screen;

According to the total failare electric current of said grounded screen, said diverting coefficient and said stake resistance, confirm the potential rise a large amount that grounded screen causes;

Potential rise a large amount according to said grounded screen causes is regulated grounded screen corresponding equipment parameter.

2. the detection method of grounding net of transformer substation design according to claim 1 is characterized in that,

When setting up the boundary element model of grounded screen, utilize the spatial relationship on grounded screen conductor and border that the grounded screen boundary element is carried out the self-adaptation subdivision, set up the boundary element model of ultra-large ground connection entoilage according to the boundary element behind the subdivision.

3. the detection method of grounding net of transformer substation design according to claim 1 is characterized in that,

Adopt matrix algorithms to calculate the stake resistance of said grounded screen.

4. the detection method of grounding net of transformer substation design according to claim 1 is characterized in that,

Adopt parallel LU decomposition algorithm to calculate said stake resistance.

5. according to the detection method of each described grounding net of transformer substation design of claim 1 to 4, it is characterized in that,

When obtaining the diverting coefficient of grounded screen, confirm the structural parameters of circuit in the electrical network, the structural parameters of transformer, the ground connection parameter of grounding net of transformer substation said earlier;

According to the method for operation of electrical network, carry out the structural parameters of circuit, transformer, grounding net of transformer substation the modeling of phase component;

According to the phase component model of the circuit of cyclic current method and foundation, transformer, grounding net of transformer substation, the fault current of finding the solution electrical network distributes, thereby obtains diverting coefficient.

6. the pick-up unit of a grounding net of transformer substation design is characterized in that, comprising:

The modelling unit is used to set up the boundary element model of grounded screen;

First acquiring unit is used to obtain the impedance operator of grounded screen conductor;

First computing unit is used for according to the impedance operator of said grounded screen conductor and the boundary element model of foundation, calculates the stake resistance of grounded screen;

Second acquisition unit is used to obtain the total failare electric current and the diverting coefficient of grounded screen;

Second computing unit is used for the total failare electric current according to said grounded screen, said diverting coefficient and said stake resistance, confirms the potential rise a large amount that grounded screen causes;

Regulon, the potential rise a large amount that is used for causing according to said grounded screen is regulated grounded screen corresponding equipment parameter.

7. the pick-up unit of grounding net of transformer substation design according to claim 6 is characterized in that,

Said modelling unit utilizes the spatial relationship on grounded screen conductor and border that the grounded screen boundary element is carried out the self-adaptation subdivision when setting up the boundary element model of grounded screen, sets up the boundary element model of ultra-large ground connection entoilage according to the boundary element behind the subdivision.

8. the pick-up unit of grounding net of transformer substation design according to claim 6 is characterized in that,

Said first computing unit adopts matrix algorithms to calculate the stake resistance of said grounded screen.

9. the pick-up unit of grounding net of transformer substation design according to claim 6 is characterized in that,

Said first computing unit adopts parallel LU decomposition algorithm to calculate said stake resistance.

10. according to the pick-up unit of each described grounding net of transformer substation design of claim 6 to 9, it is characterized in that,

Said second acquisition unit when obtaining the diverting coefficient of grounded screen, is confirmed the structural parameters of circuit in the electrical network, the structural parameters of transformer, the ground connection parameter of grounding net of transformer substation said earlier;

According to the method for operation of electrical network, carry out the structural parameters of circuit, transformer, grounding net of transformer substation the modeling of phase component;

According to the phase component model of the circuit of cyclic current method and foundation, transformer, grounding net of transformer substation, the fault current of finding the solution electrical network distributes, thereby obtains diverting coefficient.

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