CN106021848A - Extra-high voltage direct current transmission line ground total electric field shielding analysis method - Google Patents

Abstract

The invention discloses an extra-high voltage direct current transmission line ground total electric field shielding analysis method. The method includes: establishing a total electric field calculation model during erecting of shielding lines; setting a total electric field ground surface sensitive point; calculating the total electric field of the ground surface sensitive point during erecting of the shielding lines; determining if the total electric field of the ground surface sensitive point meets a preset limiting value or not, and performing optimization adjustment on the locations and the number of the shielding lines if not till the total electric field of the ground surface sensitive point meets a preset limiting value; storing the initial number and the initial locations of the shielding lines if so; and recycling further optimization on the number and the locations of the shielding lines in the condition that the total electric field meets the preset limiting value, and finally providing an optimal shielding method. Based on the Deutecsh hypothesis principle and the moment method, the method can analyze and optimize the shielding effect of the extra-high voltage direct current transmission line ground total electric field, and can provide technical references for relevant actual projects.

Description

A kind of extra high voltage direct current transmission line ground total electric field shielding analysis method

Technical field

The present invention relates to total electric field field, the total electric field shielding point of particularly a kind of extra high voltage direct current transmission line ground Analysis method.

Background technology

China natural resources skewness, load center and Energy Base are contrary distribution.Extra-high voltage direct-current transmission is a kind of It is suitable for Large Copacity, power transmission engineering remote, point-to-point, obtains fast development in China.In recent years, China has built up There is a plurality of extra high voltage direct current transmission line, more extra high voltage direct current transmission line also will be had future to build up.Along with people's environmental protection is anticipated The continuous enhancing known, the electromagnetic environment problem of extra high voltage direct current transmission line is increasingly paid close attention to by people, especially characterizes The total electric field of one of road extra-high voltage direct-current transmission line electromagnetic environment important parameter.

Calculating for the distribution of total electric field below extra-high voltage direct-current transmission line, Chinese scholars has all carried out substantial amounts of grinding Study carefully.The numerical computation method the most most typically assumed based on Deutsch.The method is relatively easy owing to calculating, and can Meet the needs of Practical Project, be put into State Grid's industry standard " HVDC aerial power transmission line fire protection technology " (DL436-91) among.But, in Practical Project, the total electric field of the extra high voltage direct current transmission line for having run divides Cloth, if it exceeds the control measure research of relevant criterion limit value, yet there are no relevant report both at home and abroad.Along with China is extensive from now on Carry out extra high voltage direct current transmission line construction, Similar Problems it would be possible to run into.

Accordingly, it would be desirable to a kind of extra high voltage direct current transmission line ground total electric field shielding analysis method.

Summary of the invention

In view of this, it is an object of the invention to provide a kind of extra high voltage direct current transmission line ground two-dimensional total electric field shielding Analysis method, it is possible to by transmission line of electricity surface state through region all in view of in calculating factor, improve transmission line of electricity Electromagnetic environment assessment accuracy.

It is an object of the invention to be realized by such technical scheme:

The extra high voltage direct current transmission line ground total electric field shielding analysis method that the present invention provides, comprises the following steps:

S1. total electric field computation model when setting up shielding line is set up；

S2., total electric field ground sensitive spot is set；

S3. the total electric field setting up shielding line ground sensitive spot is calculated；

S4. judge whether the total electric field of ground sensitive spot meets pre-set limit, if be unsatisfactory for, then the position to shielding line Put, radical is optimized adjustment, until the total electric field of ground sensitive spot meets pre-set limit；

S5. if it is satisfied, then store initial radical and the initial position of shielding line；

S6. circulation repeats ensureing under conditions of total electric field meets pre-set limit that radical and position to shielding line are carried out Optimize further；

S7., the screen method of optimum is proposed.

Further, described shielding line total electric field computation model includes determining circuit coordinate parameter, initializes shielding line root Number and position.

Further, described shielding line total electric field computation model uses and assumes principle based on Deutecsh and combine moment method Calculate the total electric field on ground when setting up shielding line, specifically comprise the following steps that

S31. transmission pressure surface is become with shielding line discretization of half-space surface the line charge of segmentation；

S32. any one calculates point to select conductive line surfaces, utilizes the nominal electric field required by moment method to determine from this point By ground or the electric lines of force on shielding line surface；

S33. set the charge density initial value on transmission pressure surface, and obtain from transmission pressure surface and along electric lines of force The charge density of spatial points and scalar function；

S34. conductive line surfaces charge density is updated, until space charge density meansigma methods meets qualifications；

S35. the total electric field at sensitive spot is calculated according to the charge density tried to achieve and scalar function.

Further, step S32 utilizes the nominal electric field required by moment method to determine from calculating and point out the electricity line of force, specifically Step is as follows:

S321. corresponding image charge is set according to image theory and sets up the discrete side of two dimensional electric field integral mathematics model Journey；

The most then selecting basic function is point territory impulse function, selects weight function according to point collocation and asks at each limit of integration Inner product, forms matrix equation；

S323. solution matrix equation, calculated charge is distributed；

S324. calculating match point error, if error is unsatisfactory for requirement, return step S31 is again discrete to field source and sets Put discrete lines electric charge；If meeting requirement to carry out next step；

S325. set step-length, utilize CHARGE DISTRIBUTION required in step S323 to determine that step-length terminal point coordinate is:

X (i+1)=x (i)+step*Ex (i)/(Ex²+Ey²)^0.5 (1)

Y (i+1)=y (i)+step*Ey (i)/(Ex²+Ey²)^0.5 (2)

In formula (1) (2), step is the size of selected step-length, and x (i), y (i) are step-length starting point coordinate；I.e. ground calculates Point, x (i+1), y (i+1) are step-length terminal point coordinate；Ex, Ey are step-length starting point x, the nominal electric field in bis-directions of y；

S326. using the terminal of each step-length as the starting point of next step-length, step S325 is repeated until the mark of step-length terminal Claim current potential to meet boundary condition, connect the step-length terminal of each step, draw from transmission pressure surface to the electric lines of force of step-length terminal；

The most again any one calculates point to select conductive line surfaces, repeats step S325, S326 until all conductive line surfaces Calculating point sends electric lines of force and draws complete.

Further, in described step S321, the foundation of two dimensional electric field integral mathematics model discrete equation is entered according to below equation OK:

It is whereinSite vector,Transmission pressure line source vector,Transmission pressure surface line source mirror image vector,Shielding Line surface line source vector,Shielding line surface line source mirror vector, l is region existing for line charge, l_jFor image line electric charge place Region.

Further, the basic function in described step S322 selects according to below equation:

$\mathrm{\λ}=\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\λ}}_n{W}_n---\left(4\right)$

Wherein, λ represents the total electrical charge distribution in field source district；λ_nRepresent CHARGE DISTRIBUTION undetermined on discrete location；W_nRepresent given Known coefficient；N represents the number that field source is discrete；L represents region existing for discrete charge.

Further, in described step S322, weight function is carried out according to below equation:

Wherein, ω_jRepresent the weight function at discrete point k；Represent site radius vector；Represent the radius vector of discrete nodes；K table Show discrete nodes；Ω represents must zone of dispersion；

The formation of the matrix equation in described step S322 is achieved by the steps of:

(1) formula (4) is substituted into formula (3), draws the discrete form of current potential integral equation:

Wherein,Representation space point current potential；ε representation space dielectric constant；α_iRepresent at transmission pressure discrete point i CHARGE DISTRIBUTION undetermined；α_jRepresent the CHARGE DISTRIBUTION undetermined at shielding line discrete point j；W_iGive at expression transmission pressure discrete point i Known coefficient；W_jRepresent the given known coefficient at shielding line discrete point j；L represents source vector；dl_iRepresent on transmission pressure Integration unit；dl_jRepresent the integration unit on shielding line；

(2) to each ω in integral domain_k(whether should be ω_k) seek inner product with formula (6), then have:

Wherein, ω_kRepresent the weight function at discrete point k；N represents transmission pressure discrete number；M represents discrete of shielding line Number；

(3) according to δ_k(7) are simplified to following formula by Functional Quality and formula (4):

Order

Then have:

The known potential matrix of all match points of transmission pressure φ；

The FACTOR P of described matrix equation_ijEmploying formulaObtain；

The FACTOR P of described matrix equation_ji' use formulaObtain.

Further, in described step S324 the verification error of match point by having solved on field domain border all match points Know that the minima of the squared difference sum of current potential and calculating current potential represents:

Wherein,For all discrete charges current potential at i-th match point；φ_0iKnown electric for i-th match point Position, conductive line surfaces φ=U, φ=0 on shielding line；

Formula (9) has following constraints: the electricity of discrete charge is free variable；The position of discrete charge must be in nothing Effect calculates in field domain:

$\sqrt{{(X_{Qd1}-x_1)}^2}+\sqrt{{(Y_{Qd1}-y_1)}^2}<r_1---\left(10\right)$

$\sqrt{{(X_{Qd2}-x_2)}^2+{(Y_{Qd2}-y_2)}^2}<r_2---\left(11\right)$

Wherein, in formula (10) and (11), X_Qd1, Y_Qd1For discrete charge coordinate on transmission pressure, X_Qd2, Y_Qd2For on shielding line Discrete charge coordinate, x₁, y₁For transmission pressure centre coordinate, x₂, y₂Shielding line centre coordinate, r₁For sub-transmission pressure radius, r₂ For shielding line radius, and use conjugate gradient method to solve the minimum in formula (3), thus the discrete charge trying to achieve optimum is big Little.

Further, the charge density initial value of the transmission pressure in described step S33 is a bit of transmission pressure surface set Two charge density initial values, specific as follows:

Positive wire surface takes ρ_biaom1+=2 ρ_m,ρ_biaom2+=3 ρ_m；

Cathode conductor surface takes ρ_biaom1-=1.5 ρ_m,ρ_biaom2-=3 ρ_m；

Wherein, U is the working voltage of transmission pressure, and U0 is the discharge inception voltage of transmission pressure, the electric lines of force step-length joint that E tries to achieve Two-dimentional nominal electric field on point.

Further, the charge density of the spatial points from transmission pressure surface and along electric lines of force in described step S33 Calculate as follows with scalar function:

Calculate scalar function the most in such a way:

Meansigma methods E0 of each sub-transmission pressure surface maximum field strength is obtained by moment method,

Equivalent bloom field intensity Eq of split conductor is obtained by Peek formula,

The scalar function drawing transmission pressure surface is A_biao=| E₀/E_q|；

S152. the electric charge of each point on electric lines of force is calculated when different transmission pressure surface charge density according to below equation Density:

Wherein, ρ represents the charge density of certain node on electric lines of force；ρ_biaoRepresent that the initial charge on transmission pressure surface is close Degree；A_biaoRepresent the scalar function that transmission pressure surface is initial；ε representation space dielectric constant；The electricity of representation space node Position；U represents wire working voltage；E representation space nominal electric field；Represent current potential integration unit；

S153. the scalar of each point on electric lines of force is calculated when different transmission pressure surface charge density according to below equation Function A:

S154. the putting down a little of institute on electric lines of force is calculated when different transmission pressure surface charge density according to below equation All charge density:

In formula, E is the two-dimentional nominal electric field of step-length node on the electric lines of force tried to achieve by moment method；

Renewal conductive line surfaces charge density in described step S34, until space charge density meansigma methods meets limits bar Part, is accomplished in that

Set

Wherein, ρ_biao3The charge density on the transmission pressure surface for updating, and calculate corresponding to ρ_biao3Through electric lines of force Upper average charge density ρ a little_m03；WhenTime, ρ_biao3It is the actual value of conductive line surfaces charge density, no Then ρ_biao1=ρ_biao2, ρ_biao2=ρ_biao3, and repeat step S152 S154 untilSet up.

Owing to have employed technique scheme, present invention have the advantage that:

A kind of extra high voltage direct current transmission line ground total electric field shielding analysis method that the present invention provides.Initially set up conjunction Become electric field shielding analysis and calculation model；It is next based on Deutecsh assume principle and combine ground when moment method calculates erection shielding line The total electric field in face；Then result of calculation is carried out analysis, see whether sensitive spot total electric field meets limit value requirement, if discontented Foot requirement, being optimized adjustment to position, the radical of shielding line, until sensitive spot meets limit value requirement, if meeting requirement, entering Optimization is carried out in radical and the position of shielding line by one step.Finally, optimum screen method is proposed.The present invention is false based on Deutecsh If principle also combines moment method, extra high voltage direct current transmission line ground total electric field can be carried out shield effectiveness analysis with excellent Change, can be that relevant Practical Project provides Technical Reference.

Other advantages, target and the feature of the present invention will be illustrated to a certain extent in the following description, and And to a certain extent, will be apparent to those skilled in the art based on to investigating hereafter, or can To be instructed from the practice of the present invention.The target of the present invention and other advantages can be wanted by description below and right Ask book to realize and obtain.

Accompanying drawing explanation

The accompanying drawing of the present invention is described as follows.

Fig. 1 is the extra high voltage direct current transmission line ground total electric field shielding analysis method flow chart of the present invention.

Fig. 2 is total electric field calculation flow chart below the shielding line of the present invention.

Fig. 3 is wire and the shielding line discretization of half-space surface schematic diagram of the present invention.

Detailed description of the invention

The invention will be further described with embodiment below in conjunction with the accompanying drawings.

Embodiment 1

As it can be seen, the extra high voltage direct current transmission line ground total electric field shielding analysis method that the present embodiment provides, bag Include following steps:

S1. total electric field computation model when setting up shielding line is set up；

S2., total electric field ground sensitive spot is set；

S3. the total electric field setting up shielding line ground sensitive spot is calculated；

S4. judge whether the total electric field of ground sensitive spot meets pre-set limit, if be unsatisfactory for, then the position to shielding line Put, radical is optimized adjustment, until the total electric field of ground sensitive spot meets pre-set limit；

S5. if it is satisfied, then store initial radical and the initial position of shielding line；

S6. circulation repeats ensureing under conditions of total electric field meets pre-set limit that radical and position to shielding line are carried out Optimize further；

S7., the screen method of optimum is proposed.

Described shielding line total electric field computation model includes determining circuit coordinate parameter, initializes shielding line radical and position Put.

Described shielding line total electric field computation model uses to be assumed principle based on Deutecsh and combines moment method and calculate When setting up shielding line, the total electric field on ground, specifically comprises the following steps that

S31. transmission pressure surface is become with shielding line discretization of half-space surface the line charge of segmentation；

S32. any one calculates point to select conductive line surfaces, utilizes the nominal electric field required by moment method to determine from this point By ground or the electric lines of force on shielding line surface；

S33. set the charge density initial value on transmission pressure surface, and obtain from transmission pressure surface and along electric lines of force The charge density of spatial points and scalar function；

S34. conductive line surfaces charge density is updated, until space charge density meansigma methods meets qualifications；

S35. the total electric field at sensitive spot is calculated according to the charge density tried to achieve and scalar function.

Utilizing the nominal electric field required by moment method to determine from calculating in step S32 and point out the electricity line of force, concrete steps are such as Under:

S321. corresponding image charge is set according to image theory and sets up the discrete side of two dimensional electric field integral mathematics model Journey；

The most then selecting basic function is point territory impulse function, selects weight function according to point collocation and asks at each limit of integration Inner product, forms matrix equation；

S323. solution matrix equation, calculated charge is distributed；

S324. calculating match point error, if error is unsatisfactory for requirement, return step S31 is again discrete to field source and sets Put discrete lines electric charge；If meeting requirement to carry out next step；

S325. set step-length, utilize CHARGE DISTRIBUTION required in step S323 to determine that step-length terminal point coordinate is:

X (i+1)=x (i)+step*Ex (i)/(Ex²+Ey²)^0.5 (1)

Y (i+1)=y (i)+step*Ey (i)/(Ex²+Ey²)^0.5 (2)

In formula (1) (2), step is the size of selected step-length, and x (i), y (i) are step-length starting point coordinate；I.e. ground calculates point, X (i+1), y (i+1) are step-length terminal point coordinate；Ex, Ey are step-length starting point x, the nominal electric field in bis-directions of y；

S326. using the terminal of each step-length as the starting point of next step-length, step S325 is repeated until the mark of step-length terminal Claim current potential to meet boundary condition, connect the step-length terminal of each step, draw from transmission pressure surface to the electric lines of force of step-length terminal；

The most again any one calculates point to select conductive line surfaces, repeats step S325, S326 until all conductive line surfaces Calculating point sends electric lines of force and draws complete.

In described step S321, the foundation of two dimensional electric field integral mathematics model discrete equation is carried out according to below equation:

It is whereinSite vector,Transmission pressure line source vector,Transmission pressure surface line source mirror image vector,Shielding Line surface line source vector,Shielding line surface line source mirror vector, l is region existing for line charge, l_jFor image line electric charge place Region.

Basic function in described step S322 selects according to below equation:

$\mathrm{\&lambda;}=\underset{n=1}{\overset{N}{\mathrm{\&Sigma;}}}{\mathrm{\&lambda;}}_n{W}_n---\left(4\right)$

Wherein, λ represents the total electrical charge distribution in field source district；λ_nRepresent CHARGE DISTRIBUTION undetermined on discrete location；W_nRepresent given Known coefficient；N represents the number that field source is discrete；L represents region existing for discrete charge.

In described step S322, weight function is carried out according to below equation:

Wherein, ω_jRepresent the weight function at discrete point k；Represent site radius vector；Represent the radius vector of discrete nodes；K table Show discrete nodes；Ω represents must zone of dispersion.

The formation of the matrix equation in described step S322 is achieved by the steps of:

(1) formula (4) is substituted into formula (3), draws the discrete form of current potential integral equation:

Wherein,Representation space point current potential；ε representation space dielectric constant；α_iRepresent at transmission pressure discrete point i CHARGE DISTRIBUTION undetermined；α_jRepresent the CHARGE DISTRIBUTION undetermined at shielding line discrete point j；W_iGive at expression transmission pressure discrete point i Known coefficient；W_jRepresent the given known coefficient at shielding line discrete point j；L represents source vector；dl_iRepresent on transmission pressure Integration unit；dl_jRepresent the integration unit on shielding line；

(2) to each ω in integral domain_k(whether should be ω_k) seek inner product with formula (6), then have:

Wherein, ω_kRepresent the weight function at discrete point k；N represents transmission pressure discrete number；M represents discrete of shielding line Number；

(3) according to δ_k(7) are simplified to following formula by Functional Quality and formula (4):

Order

Then have:

The known potential matrix of all match points of transmission pressure φ；

The FACTOR P of described matrix equation_ijEmploying formulaObtain；

The FACTOR P of described matrix equation_ji' use formulaObtain.

In described step S324, the verification error of match point is by solving the known potential of all match points on field domain border Represent with the minima of the squared difference sum calculating current potential:

Wherein,For all discrete charges current potential at i-th match point；φ_0iKnown electric for i-th match point Position, conductive line surfaces φ=U, φ=0 on shielding line；

Formula (9) has following constraints: the electricity of discrete charge is free variable；The position of discrete charge must be in nothing Effect calculates in field domain:

$\sqrt{{(X_{Qd1}-x_1)}^2}+\sqrt{{(Y_{Qd1}-y_1)}^2}<r_1---\left(10\right)$

$\sqrt{{(X_{Qd2}-x_2)}^2+{(Y_{Qd2}-y_2)}^2}<r_2---\left(11\right)$

Wherein, in formula (10) and (11), X_Qd1, Y_Qd1For discrete charge coordinate on transmission pressure, X_Qd2, Y_Qd2For on shielding line Discrete charge coordinate, x₁, y₁For transmission pressure centre coordinate, x₂, y₂Shielding line centre coordinate, r₁For sub-transmission pressure radius, r₂ For shielding line radius, and use conjugate gradient method to solve the minimum in formula (3), thus the discrete charge trying to achieve optimum is big Little.

Two electricity of any that charge density initial value is transmission pressure surface set of the transmission pressure in described step S33 Lotus density initial value, specific as follows:

Positive wire surface takes ρ_biaom1+=2 ρ_m,ρ_biaom2+=3 ρ_m；

Cathode conductor surface takes ρ_biaom1-=1.5 ρ_m,ρ_biaom2-=3 ρ_m；

Wherein, U is the working voltage of transmission pressure, and U0 is the discharge inception voltage of transmission pressure, the electric lines of force step-length joint that E tries to achieve Two-dimentional nominal electric field on point.

In described step S33 from transmission pressure surface and along the charge density of spatial points of electric lines of force and scalar letter Number calculates as follows:

Calculate scalar function the most in such a way:

Meansigma methods E0 of each sub-transmission pressure surface maximum field strength is obtained by moment method,

Equivalent bloom field intensity Eq of split conductor is obtained by Peek formula,

The scalar function drawing transmission pressure surface is A_biao=| E₀/E_q|；

S152. the electric charge of each point on electric lines of force is calculated when different transmission pressure surface charge density according to below equation Density:

Wherein, ρ represents the charge density of certain node on electric lines of force；ρ_biaoRepresent that the initial charge on transmission pressure surface is close Degree；A_biaO represents the scalar function that transmission pressure surface is initial；ε representation space dielectric constant；The electricity of representation space node Position；U represents wire working voltage；E representation space nominal electric field；Represent current potential integration unit；

S153. the scalar of each point on electric lines of force is calculated when different transmission pressure surface charge density according to below equation Function A:

S154. the putting down a little of institute on electric lines of force is calculated when different transmission pressure surface charge density according to below equation All charge density:

In formula, E is the two-dimentional nominal electric field of step-length node on the electric lines of force tried to achieve by moment method；

Renewal conductive line surfaces charge density in described step S34, until space charge density meansigma methods meets limits bar Part, is accomplished in that

Set

Wherein, ρ_biao3The charge density on the transmission pressure surface for updating, and calculate corresponding to ρ_biao3Through electric lines of force Upper average charge density ρ a little_m03；WhenTime, ρ_biao3It is the actual value of conductive line surfaces charge density, Otherwise ρ_biao1=ρ_biao2, ρ_biao2=ρ_biao3, and repeat step S152 S154 untilSet up.

In step S3, ground total electric field is corresponding according to the charge density actual value on electric lines of force at ground Scalar function A and nominal electric field E, is calculated by formula Es=AE.

Seeing in step S4 whether sensitive spot total electric field meets limit value requirement, limit value size is the attribute according to sensitive spot (house owed by a citizen surface, open area etc.) are different and different, have the quick of multiple different attribute in needing to carry out the region shielded During sense point, it is as the criterion with minimum limit value.

In step S4, position, radical to shielding line are optimized adjustment, and the radical specifically referring to shielding line is optimized and revised Mainly improve shield effectiveness by the radical of increase or minimizing shielding line；The position optimization of shielding line adjusts and mainly includes screen Covering the height of line, the distance from transmission line of electricity adjusts.

In step S6 ensure the radical of shielding line and position to be carried out under conditions of total electric field meets pre-set limit into One-step optimization, specifically refers in the case of sensitive spot total electric field meets limit value requirement, carries out radical, the position of shielding line Further optimization, to reach to utilize minimum shielding line to obtain optimum shield effectiveness.

Step S7 proposes the screen method of optimum, specifically refers to the total electric field shielding of extra high voltage direct current transmission line ground After analysis method carries out total electric field shielding, it is finally reached and saves material and the excellent effect of shield effectiveness.

Embodiment 2

The extra high voltage direct current transmission line ground total electric field shielding analysis method that the present embodiment provides, including walking as follows Rapid:

A. total electric field shield analysis computation model is set up；

B. it is next based on Deutecsh assume principle and combine the total electric field on ground when moment method calculates erection shielding line；

The most then result of calculation is carried out analysis, see whether sensitive spot total electric field meets limit value requirement, if be unsatisfactory for Requirement, is optimized adjustment to position, the radical of shielding line, until sensitive spot meets limit value requirement.

If d. meeting requirement, further position, the radical of shielding line is optimized.

E. last, optimum screen method is proposed.

The present embodiment sets up total electric field shield analysis computation model, comprises determining that circuit coordinate parameter, power frequency electric Field sensitive space of points location parameter, tentatively provides radical and the position of shielding line；

Assume principle based on Deutecsh and combine the total electric field on ground, its step when moment method calculates erection shielding line As follows:

S31. transmission pressure surface is become the line charge of segmentation, as shown in Figure 3 with shielding line discretization of half-space surface.

S32. any one calculates point to select conductive line surfaces, utilizes the nominal electric field required by moment method to determine from this point By ground or the electric lines of force on shielding line surface；

S33. set the charge density initial value on transmission pressure surface, and obtain from transmission pressure surface and along electric lines of force The charge density of spatial points and scalar function；

S34. conductive line surfaces charge density is updated, until space charge density meansigma methods meets qualifications；

S35. the total electric field at ground is calculated according to the charge density tried to achieve and scalar function

The present embodiment utilizes nominal electric field determine electric lines of force from this point in step S32, specifically comprise the following steps that

S41. corresponding image charge is set according to image theory and sets up the discrete side of two dimensional electric field integral mathematics model Journey；

The most then selecting basic function is point territory impulse function, selects weight function and in each limit of integration is asked according to point collocation Long-pending, form matrix equation；

S43. solution matrix equation, calculated charge is distributed

S44. calculating match point error, if error is unsatisfactory for requirement, return step S31 is again discrete to field source and arranges Discrete lines electric charge；If meeting requirement to carry out next step.

S45. set a step-length, utilize CHARGE DISTRIBUTION required in step S43 to determine that step-length terminal point coordinate is:

X (i+1)=x (i)+step*Ex (i)/(Ex^2+Ey^2) ^0.5 (1)

Y (i+1)=y (i)+step*Ey (i)/(Ex^2+Ey^2) ^0.5 (2)

In formula (1) (2), step is the size of selected step-length, and x (i), y (i) are that (i.e. ground calculates step-length starting point coordinate Point), x (i+1), y (i+1) they are step-length terminal point coordinate；Ex, Ey are step-length starting point x, the nominal electric field in bis-directions of y.

S46. using the terminal of each step-length as the starting point of next step-length, step S45 is repeated until the nominal of step-length terminal Current potential meets boundary condition, connects the step-length terminal of each step, draws the electric lines of force calculating point from transmission pressure surface to ground；

The most again any one calculates point to select conductive line surfaces, repeats step S45, S46 until all conductive line surfaces meters Calculation point sends electric lines of force and draws complete.

The field source of the two dimensional electric field integral mathematics model discrete equation set up in step S41 in the present embodiment includes wire table Upper thread electric charge and shielding line surface line electric charge:

Wherein, forSite vector,Transmission pressure line source vector,Transmission pressure surface line source mirror image vector,Screen Cover line surface line source vector,Shielding line surface line source mirror vector, l is region existing for line charge, l_jFor image line electric charge institute In region.

Basic function selected in step S42 is a point territory impulse function, as follows:

$\mathrm{\&lambda;}=\underset{n=1}{\overset{N}{\mathrm{\&Sigma;}}}{\mathrm{\&lambda;}}_n{W}_n---\left(4\right)$

In the present embodiment in step S42, the weight function selected according to point collocation is as follows:

In step S42, the formation of matrix equation is achieved by the steps of:

(1) formula (4) is substituted into formula (3), draws the discrete form of current potential integral equation:

(2) in integral domain, each ω j is sought inner product with formula (6), then has:

(3) according to δ_j(7) can be simplified to following formula by Functional Quality and formula (4):

Order

Then have:

Wherein, α_iFor the line charge of transmission pressure discretization of half-space surface, α_jLine charge for shielded conductor discretization of half-space surface

In the present embodiment, FACTOR P ij of matrix equation uses formulaObtain.

The FACTOR P of matrix equation in the present embodiment_ji' use formulaObtain.

In the present embodiment in step S44 the verification error of match point by solving the known of all match points on field domain border The minima of the squared difference sum of current potential and calculating current potential represents:

Wherein,For all discrete charges current potential at i-th match point；φ 0i is the known electric of i-th match point Position, conductive line surfaces φ=U, φ=0 on shielding line；Formula (9) has following constraints: the electricity of discrete charge is for freely to become Amount；The position of discrete charge must be in effectively calculating field domain:

$\sqrt{{{(}_{Qd}-x_0)}^2}+\sqrt{{(Y_{Qd}-y_0)}^2}<r---\left(10\right)$

y_Q-f(x_Q) < 0i=m+1 ... n (11)

Wherein, in formula (10) and (11), xQd, yQd are discrete charge coordinate on wire, and xo, yo are that sub-conductor center is sat Mark, r is sub-conductor radius, and zQ is groundwater simulation electric charge vertical coordinate, and m is sub-conductor number, and uses conjugate gradient method to solve formula (9) minimum in, thus try to achieve the discrete charge of optimum.

In the present embodiment in step S44, rearrange discrete charge and reach by mistake by increasing discrete line charge number Difference requirement.

In the present embodiment in step S3 charge density initial value is transmission pressure surface set any the two of transmission pressure Individual charge density initial value, it may be assumed that positive wire surface takes ρ_biaom1+=2 ρ_m,ρ_biaom2+=3 ρ_m, cathode conductor surface takes ρ_biaom1-= 1.5ρ_m,ρ_biaom2-=3 ρ_m,

Wherein:U is the working voltage of transmission pressure, and U0 is the discharge inception voltage of transmission pressure, and E tries to achieve Electric lines of force step-length node on two-dimentional nominal electric field.

In the present embodiment in step S3 from transmission pressure surface and along the charge density of spatial points of electric lines of force and mark Flow function calculates as follows:

S151. obtained meansigma methods E0 of each sub-transmission pressure surface maximum field strength by moment method, Peek formula obtain point Split equivalent bloom field intensity Eq of wire, show that the scalar function on transmission pressure surface is A_biao=| E₀/E_q|；

S152. by formulaCalculate on different transmission pressure surfaces The charge density of each point on electric lines of force during charge density；

S153. by formulaCalculate in different transmission pressure surface charges The scalar function A of each point on electric lines of force during density；

S154. by formulaCalculate the electric power when different transmission pressure surface charge density On line average charge density a little,

In formula (12), (13) and (14), E is the two-dimentional nominal electricity of step-length node on the electric lines of force tried to achieve by moment method ?；

The present embodiment updates conductive line surfaces charge density, until space charge density meansigma methods meets qualifications, logical Cross following manner to realize:

Set

Wherein ρ_biao3The charge density on the transmission pressure surface for updating, and calculate corresponding to ρ_biao3Through electric lines of force Upper average charge density ρ a little_m03；WhenTime, ρ_biao3It is the actual value of conductive line surfaces charge density, Otherwise ρ_biao1=ρ_biao2, ρ_biao2=ρ_biao3, and repeat step S152 S154 untilSet up.

Charge density actual value ρ according to wire in step b in the present embodiment_m03The scalar function A of corresponding spatial points With two dimension nominal electric field E, formula Es=AE calculate the two-dimentional total electric field on ground.

Seeing in step c in the present embodiment whether sensitive spot total electric field meets limit value requirement, limit value size is according to sensitivity The attribute (house owed by a citizen surface, open area etc.) of point is different and different, has multiple difference in needing to carry out the region shielded During the sensitive spot of attribute, it is as the criterion with minimum limit value.

In the present embodiment, in step c, position, radical to shielding line is optimized adjustment, it is characterised in that the root of shielding line Number is optimized and revised and is mainly improved shield effectiveness by the radical of increase or minimizing shielding line；The position optimization of shielding line adjusts Mainly including the height of shielding line, the distance from transmission line of electricity adjusts.

The radical of shielding line is optimized in step d by the present embodiment further, the fullest at sensitive spot total electric field In the case of foot limit value requires, the further optimization that the radical of shielding line, position are carried out.

The present embodiment proposes the screen method of optimum, it is characterised in that extra high voltage direct current transmission line ground in step e After total electric field shielding analysis method carries out total electric field shielding, it is finally reached and saves material and the excellent effect of shield effectiveness.

Finally illustrating, above example is only in order to illustrate technical scheme and unrestricted, although with reference to relatively The present invention has been described in detail by good embodiment, it will be understood by those within the art that, can be to the skill of the present invention Art scheme is modified or equivalent, and without deviating from objective and the scope of the technical program, it all should be contained in the present invention Right in the middle of.

Claims (14)

1. an extra high voltage direct current transmission line ground total electric field shielding analysis method, it is characterised in that: comprise the following steps:

S1. total electric field computation model when setting up shielding line is set up；

S2., total electric field ground sensitive spot is set；

S3. the total electric field setting up shielding line ground sensitive spot is calculated；

S4. judge whether the total electric field of ground sensitive spot meets pre-set limit, if be unsatisfactory for, then to the position of shielding line, Radical is optimized adjustment, until the total electric field of ground sensitive spot meets pre-set limit；

S5. if it is satisfied, then store initial radical and the initial position of shielding line；

S6. circulation repeats ensureing under conditions of total electric field meets pre-set limit that radical and position to shielding line are carried out into one Step optimizes；

S7., the screen method of optimum is proposed.

2. extra high voltage direct current transmission line ground as claimed in claim 1 total electric field shielding analysis method, it is characterised in that: Described shielding line total electric field computation model includes determining circuit coordinate parameter, initializes shielding line radical and position.

3. extra high voltage direct current transmission line ground as claimed in claim 1 total electric field shielding analysis method, it is characterised in that: Described shielding line total electric field computation model use based on Deutecsh assume principle and combine moment method calculate erection shielding During line, the total electric field on ground, specifically comprises the following steps that

S31. transmission pressure surface is become with shielding line discretization of half-space surface the line charge of segmentation；

S32. select conductive line surfaces any one calculate point, utilize the nominal electric field required by moment method determine from this point by Ground or the electric lines of force on shielding line surface；

S33. set the charge density initial value on transmission pressure surface, and obtain from transmission pressure surface and along the space of electric lines of force The charge density of each point and scalar function；

S34. conductive line surfaces charge density is updated, until space charge density meansigma methods meets qualifications；

S35. the total electric field at sensitive spot is calculated according to the charge density tried to achieve and scalar function.

4. extra high voltage direct current transmission line ground as claimed in claim 3 total electric field shielding analysis method, it is characterised in that: Step S32 utilizes the nominal electric field required by moment method determine from calculating to point out the electricity line of force, specifically comprise the following steps that

S321. corresponding image charge is set according to image theory and sets up the discrete equation of two dimensional electric field integral mathematics model；

The most then selecting basic function is point territory impulse function, selects weight function according to point collocation and seeks inner product at each limit of integration, Form matrix equation；

S323. solution matrix equation, calculated charge is distributed；

S324. calculate match point error, if error is unsatisfactory for requirement, return step S31 again discrete to field source and arrange from Loose wire electric charge；If meeting requirement to carry out next step；

S325. set step-length, utilize CHARGE DISTRIBUTION required in step S323 to determine that step-length terminal point coordinate is:

X (i+1)=x (i)+step*Ex (i)/(Ex²+Ey²)^0.5 (1)

Y (i+1)=y (i)+step*Ey (i)/(Ex²+Ey²)^0.5 (2)

In formula (1) (2), step is the size of selected step-length, and x (i), y (i) are step-length starting point coordinate；I.e. ground calculates point, x (i+ 1), y (i+1) is step-length terminal point coordinate；Ex, Ey are step-length starting point x, the nominal electric field in bis-directions of y；

S326. using the terminal of each step-length as the starting point of next step-length, step S325 is repeated until the nominal of step-length terminal is electric Position meets boundary condition, connects the step-length terminal of each step, draws from transmission pressure surface to the electric lines of force of step-length terminal；

The most again any one calculates point to select conductive line surfaces, repeats step S325, S326 until all conductive line surfaces calculate Point sends electric lines of force and draws complete.

5. extra high voltage direct current transmission line ground as claimed in claim 4 total electric field shielding analysis method, it is characterised in that: In described step S321, the foundation of two dimensional electric field integral mathematics model discrete equation is carried out according to below equation:

It is whereinSite vector,Transmission pressure line source vector,Transmission pressure surface line source mirror image vector,Shielding line table Upper thread source vector,Shielding line surface line source mirror vector, l is region existing for line charge, l_jFor image line electric charge location Territory.

6. extra high voltage direct current transmission line ground as claimed in claim 4 total electric field shielding analysis method, it is characterised in that: Basic function in described step S322 selects according to below equation:

Wherein, λ represents the total electrical charge distribution in field source district；λ_nRepresent CHARGE DISTRIBUTION undetermined on discrete location；W_nRepresent and given Know coefficient；N represents the number that field source is discrete；L represents region existing for discrete charge.

7. extra high voltage direct current transmission line ground as claimed in claim 4 total electric field shielding analysis method, it is characterised in that: In described step S322, weight function is carried out according to below equation:

Wherein, ω_jRepresent the weight function at discrete point k；Represent site radius vector；Represent the radius vector of discrete nodes；K represents discrete Node；Ω represents must zone of dispersion；

The formation of the matrix equation in described step S322 is achieved by the steps of:

(1) formula (4) is substituted into formula (3), draws the discrete form of current potential integral equation:

Wherein,Representation space point current potential；ε representation space dielectric constant；α_iRepresent at transmission pressure discrete point i is undetermined CHARGE DISTRIBUTION；α_jRepresent the CHARGE DISTRIBUTION undetermined at shielding line discrete point j；W_iGive at expression transmission pressure discrete point i is known Coefficient；W_jRepresent the given known coefficient at shielding line discrete point j；L represents source vector；dl_iRepresent the integration on transmission pressure Unit；dl_jRepresent the integration unit on shielding line；

(2) to each ω in integral domain_k(whether should be ω_k) seek inner product with formula (6), then have:

Wherein, ω_kRepresent the weight function at discrete point k；N represents transmission pressure discrete number；M represents shielding line discrete number；

(3) according to δ_k(7) are simplified to following formula by Functional Quality and formula (4):

Order

Then have:

The known potential matrix of all match points of transmission pressure φ；

The FACTOR P of described matrix equation_ijEmploying formulaObtain；

The FACTOR P of described matrix equation_ji' use formulaObtain.

8. extra high voltage direct current transmission line ground as claimed in claim 4 total electric field shielding analysis method, it is characterised in that: In described step S324, the verification error of match point is by solving the known potential of all match points and calculating electricity on field domain border The minima of the squared difference sum of position represents:

Wherein,For all discrete charges current potential at i-th match point；φ_0iFor the known potential of i-th match point, lead Line surface φ=U, φ=0 on shielding line；

Formula (9) has following constraints: the electricity of discrete charge is free variable；The position of discrete charge must be at invalid meter In calculation field domain:

Wherein, in formula (10) and (11), X_Qd1, Y_Qd1For discrete charge coordinate on transmission pressure, X_Qd2, Y_Qd2For discrete on shielding line Electric charge coordinate, x₁, y₁For transmission pressure centre coordinate, x₂, y₂Shielding line centre coordinate, r₁For sub-transmission pressure radius, r₂For screen Cover line radius, and use conjugate gradient method to solve the minimum in formula (3), thus try to achieve the discrete charge size of optimum.

9. extra high voltage direct current transmission line ground as claimed in claim 3 total electric field shielding analysis method, it is characterised in that: At the beginning of two charge density of any that charge density initial value is transmission pressure surface set of the transmission pressure in described step S33 Value, specific as follows:

Positive wire surface takes ρ_biaom1+=2 ρ_m,ρ_biaom2+=3 ρ_m；

Cathode conductor surface takes ρ_biaom1-=1.5 ρ_m,ρ_biaom2-=3 ρ_m；

Wherein, U is the working voltage of transmission pressure, and U0 is the discharge inception voltage of transmission pressure, on the electric lines of force step-length node that E tries to achieve Two-dimentional nominal electric field.

10. extra high voltage direct current transmission line ground as claimed in claim 3 total electric field shielding analysis method, its feature exists In: leading to from transmission pressure surface and along the charge density of spatial points and the scalar function of electric lines of force in described step S33 Cross following steps to calculate:

Calculate scalar function the most in such a way:

Meansigma methods E0 of each sub-transmission pressure surface maximum field strength is obtained by moment method,

Equivalent bloom field intensity Eq of split conductor is obtained by Peek formula,

The scalar function drawing transmission pressure surface is A_biao=| E₀/E_q|；

S152. the electric charge of each point on electric lines of force is calculated when different transmission pressure surface charge density according to below equation close Degree:

Wherein, ρ represents the charge density of certain node on electric lines of force；ρ_biaoRepresent the initial charge density on transmission pressure surface；A_biao Represent the scalar function that transmission pressure surface is initial；ε representation space dielectric constant；The current potential of representation space node；U represents Wire working voltage；E representation space nominal electric field；Represent current potential integration unit；

S153. the scalar function of each point on electric lines of force is calculated when different transmission pressure surface charge density according to below equation A:

S154. a little average the most electric of institute on electric lines of force is calculated when different transmission pressure surface charge density according to below equation Lotus density:

In formula, E is the two-dimentional nominal electric field of step-length node on the electric lines of force tried to achieve by moment method；

Renewal conductive line surfaces charge density in described step S34, until space charge density meansigma methods meets qualifications, logical Cross following manner to realize:

Set

Wherein, ρ_biao3The charge density on the transmission pressure surface for updating, and calculate corresponding to ρ_biao3Institute on electric lines of force Average charge density ρ a little_m03；WhenTime, ρ_biao3It is the actual value of conductive line surfaces charge density, otherwise ρ_biao1=ρ_biao2, ρ_biao2=ρ_biao3, and repeat step S152 S154 untilSet up.

11. extra high voltage direct current transmission line ground as claimed in claim 1 total electric field shielding analysis methods, its feature exists In: the ground total electric field in described step S3 is the mark corresponding according to the charge density actual value on electric lines of force at ground Flow function A and nominal electric field E, is calculated by formula Es=AE.

12. extra high voltage direct current transmission line ground as claimed in claim 1 total electric field shielding analysis methods, its feature exists In the minimum limit value that the attribute for ground sensitive spot of: the pre-set limit in described step S4 is corresponding.

13. extra high voltage direct current transmission line ground as claimed in claim 1 total electric field shielding analysis methods, its feature exists In: in described step S4, position, radical to shielding line are optimized adjustment, and the described radical to shielding line is optimized adjustment It is to be realized by the radical of increase or minimizing shielding line；It is by screen that the described position to shielding line is optimized adjustment Cover the height of line and realize from the distance of transmission line of electricity.

14. extra high voltage direct current transmission line ground as claimed in claim 1 total electric field shielding analysis methods, its feature exists In: described step S6 is ensureing under conditions of total electric field meets pre-set limit that radical and position to shielding line are carried out into one Step optimizes, and specifically refers in the case of sensitive spot total electric field meets limit value requirement, carries out radical, the position of shielding line Adjust.