CN104269745A - Single-span hanger tubular bus model selection and arrangement method for transformer substation - Google Patents

Abstract

The invention discloses a single-span hanger tubular bus model selection and arrangement method for a transformer substation. The method comprises the following steps: initially setting the span and phase interval of a tubular bus; selecting a certain bus model; determining values of basic factors under various working conditions; calculating stress on the tubular bus under the action of dead weight and maximum wind speed and the action of dead weight and ice coating and in case of short-circuit and earthquake respectively; judging whether the calculated stress on the tubular bus under each condition is weaker than maximum permissible stress on the tubular bus or not; calculating the flexibility of the tubular bus; judging whether the flexibility of the tubular bus is lower than a set value or not. The method has the beneficial effects that the influence of different meteorological condition factors on the tubular bus is taken into full account, electrics and mechanics are reasonably integrated, the shortcoming that a single-span hanger tubular bus is selected only by virtue of an electrical theory or experiences in practical engineering is overcome, errors caused by human factors are reduced, and the normal running of the transformer substation is ensured.

Description

Transformer station's single span suspention cast bus bar model selection method for arranging

Technical field

The present invention relates to transformer station's single span suspention cast bus bar model selection method for arranging.

Background technology

In transformer station's layout design, tube type bus scheme is the main flow in outdoor arrangement, and arrangement is various, the arrangement form of tube type bus is mainly divided into supports tube type bus and suspention tube type bus, wherein support that the selection method of tube type bus is gradually improved, and the selection method suspending tube type bus in midair is in the blank stage substantially, do not have perfect type selecting process and counting system, " power engineering electrical design handbook " and relevant books and journal article also do not have solution.

Suspention tube type bus is applied in the transformer station of 500kV and more voltage levels more, type selecting is mainly selected according to busbar carrying capacity and engineering experience, due to domestic 500kV and above transformer station arrangement more conventional, adopt busbar carrying capacity large, therefore very large according to the tube type bus diameter of ampacity selection, substantially can meet the requirement of stress and amount of deflection.But the transformer station very large for suspention tube type bus span, centralized load change in location, busbar carrying capacity are less, especially for foreign project, if comprehensively calculate without system and carry out tube type bus type selecting, reasonable construction, adopt tube type bus probably under some operating mode, not meet stress and amount of deflection requirement, its consequence gently then causes bus to become curved, affects the reliable connection of electric equipment; Heavy then cause bus directly to rupture, transformer station has a power failure, and brings great hidden danger to safety in production.

How rationally scientifically select suspention tube type bus to be a great problem in Substation Design, be directly connected to the reliability of transformer station, the stability of electric power system, concern the fail safe of activity in production, affect people's security of the lives and property.

Summary of the invention

Object of the present invention is exactly to solve the problem, propose a kind of transformer station single span suspention cast bus bar model selection method for arranging, the method has taken into full account the impact of DIFFERENT METEOROLOGICAL CONDITIONS factor on tube type bus, achieves the accurate type selecting of transformer station's suspention tube type bus.

To achieve these goals, the present invention adopts following technical scheme:

A kind of transformer station single span suspention cast bus bar model selection method for arranging, comprises the steps:

Step one: the span of initial setting tube type bus and spaced apart;

Step 2: selected certain model bus in alternative tube type bus;

Step 3: under determining various operating mode, the value of Fundamentals; Specifically comprise: about coefficient of safety and characteristic value of load value standard, the value value standard of wind factor, the value value standard of icing factor, the computational methods of short-circuit electromotive force, the computational methods of seismic force, tube type bus Load Combination condition, the maximum allowable stress of material and the deflection limit value of tubular conductor;

Step 4: gather the weight parameter of insulator string along the projected length parameter of tube type bus axis, the vertical projected length parameter of insulator string and insulator string respectively, under calculating deadweight and maximum wind velocity effect respectively, conduct oneself with dignity and under icing effect, short circuit and earthquake time tube type bus suffered by stress;

Step 5: suffered by the tube type bus calculated under judging above-mentioned often kind of situation, whether stress is all less than the maximum allowable stress of tube type bus, if so, goes to step six; If under having a kind of situation at least, suffered by tube type bus, stress is more than or equal to the maximum allowable stress of tube type bus, then traversal step two to step 4;

Step 6: calculate tube type bus amount of deflection;

Step 7: in determining step six, whether tube type bus amount of deflection is less than set point, if, determine that the model of tube type bus, span and spaced apart are respectively tube type bus model, span and the spaced apart set in step one and step 2, otherwise, traversal step two to step 6.

In described step 4, calculating is conducted oneself with dignity and under maximum wind velocity effect, the concrete grammar of stress suffered by tube type bus is:

(4-11) the spaning middle section moment M corresponding to computer tube deadweight _gz; Calculate the spaning middle section moment M corresponding to gravity of downlead _jz; Calculate the spaning middle section moment M corresponding to maximum wind velocity _fz; Described maximum wind velocity, according to the difference in geographical position, gets the maximum of relevant position historical wind speed data;

(4-12) spaning middle section moment M is synthesized respectively according to the section turn moment of above-mentioned calculating ₁

$M_1=\sqrt{M_{\mathrm{fz}}^2+(M_{\mathrm{Gz}}^2+M_{\mathrm{jz}}^2)}$

(4-13) the pulling force R of tube type bus is calculated ₁;

$R_1=\frac{h}{v}(\mathrm{PG}+\mathrm{PC})$

In formula, h is the projected length of insulator string along tube type bus axis; V is the vertical projected length of insulator string; PG is the half of all vertical loads on tube type bus; PC is the gravity of insulator string;

(4-14) according to the pulling force R of tube type bus ₁with synthesis spaning middle section moment M ₁calculated stress σ ₁;

${\mathrm{\σ}}_1=\frac{M_1}{W}+\frac{R_1}{A};$

Wherein, W is the section factor of tube type bus; A is the area of section of tube type bus.

In described step 4, calculating is conducted oneself with dignity and under icing effect, the concrete grammar of stress suffered by tube type bus is:

(4-21) the spaning middle section moment M corresponding to computer tube deadweight _gz; Calculate the spaning middle section moment M corresponding to gravity of downlead _jz; Spaning middle section moment M corresponding during calculating ice load _bz; Calculate the spaning middle section moment M corresponding to wind speed during icing _bfz;

(4-22) according to the section turn moment of above-mentioned calculating synthesis spaning middle section moment M ' ₁;

$M_1^{\′}=\sqrt{M_{\mathrm{bfz}}^2+(M_{\mathrm{Gz}}^2+M_{\mathrm{jz}}^2+M_{\mathrm{bz}}^2)}$

(4-23) the pulling force R of tube type bus is calculated ₂;

$R_2=\frac{h}{v}(\mathrm{PG}+\mathrm{PC})$

R ₂with R ₁computing formula difference is, different to the calculating value of PG.

(4-24) according to the pulling force R of tube type bus ₂with synthesis spaning middle section moment M ' ₁calculated stress σ ' ₁;

${{\mathrm{\σ}}^{\′}}_1=\frac{{M_1}^{\′}}{W}+\frac{R_2}{A};$

Wherein, W is the section factor of tube type bus; A is the area of section of tube type bus.

In described step 4, during calculating short circuit, suffered by tube type bus, the concrete grammar of stress is:

(4-31) the spaning middle section moment M corresponding to computer tube deadweight _gz; Calculate the spaning middle section moment M corresponding to gravity of downlead _jz; Spaning middle section moment M corresponding during calculating short circuit _dz; Calculate the spaning middle section moment M corresponding to 50% maximum wind velocity _50%fz;

(4-32) according to the section turn moment synthesis spaning middle section moment M of above-mentioned calculating " ₁;

$M_1^{\′\′}=\sqrt{(M_{\mathrm{dz}}^2+M_{50\%\mathrm{fz}}^2)+(M_{\mathrm{Gz}}^2+M_{\mathrm{jz}}^2)}$

(4-33) the pulling force R of tube type bus is calculated ₃;

$R_3=\frac{h}{v}(\mathrm{PG}+\mathrm{PC})$

The pulling force R of tube type bus under Short-circuit Working Condition ₃with the pulling force R of tube type bus under deadweight maximum wind velocity operating mode ₁identical.

(4-34) according to the pulling force R of tube type bus ₃with synthesis spaning middle section moment M " ₁calculated stress σ " ₁;

${{\mathrm{\σ}}^{\′\′}}_1=\frac{{M_1}^{\′\′}}{W}+\frac{R_3}{A};$

Wherein, W is the section factor of tube type bus; A is the area of section of tube type bus.

In described step 4, during calculating earthquake, suffered by tube type bus, the concrete grammar of stress is:

(4-41) the spaning middle section moment M corresponding to computer tube deadweight _gz;

Calculate the spaning middle section moment M corresponding to gravity of downlead _jz;

Spaning middle section moment M corresponding during calculating earthquake _ez;

Calculate the spaning middle section moment M corresponding to 25% maximum wind velocity _25%fz;

(4-42) according to the section turn moment synthesis spaning middle section moment M of above-mentioned calculating " ' ₁;

$M_1^{\′\′\′}=\sqrt{(M_{\mathrm{ez}}^2+M_{25\%\mathrm{fz}}^2)+(M_{\mathrm{Gz}}^2+M_{\mathrm{jz}}^2)}$

(4-43) the pulling force R of tube type bus is calculated ₄;

R ₄＝R ₁+R _V

R in formula _vfor the pulling force under Vertical Earthquake Loads.

(4-44) according to the pulling force R of tube type bus ₄with synthesis spaning middle section moment M " ' ₁calculated stress σ " ' ₁;

${{\mathrm{\σ}}^{\′\′\′}}_1=\frac{{M_1}^{\′\′\′}}{W}+\frac{R_4}{A};$

Wherein, W is the section factor of tube type bus; A is the area of section of tube type bus.

Spaning middle section moment M corresponding to described computer tube deadweight _gzmethod be:

$M_{\mathrm{Gz}}=q(\frac{l^2}{8}-\frac{c^2}{2})$

Wherein, q is the gravity of tube type bus line unit length; L is the distance between tube type bus two hitch point; C is the distance between hitch point and tube type bus thread end.

The method of spaning middle section moment of flexure corresponding when wind speed when described calculating maximum wind velocity, ice load, icing, short circuit, 50% maximum wind velocity are conducted oneself with dignity with computer tube with the method for spaning middle section moment of flexure corresponding during 25% maximum wind velocity is identical, and the gravity q of the tube type bus unit length just under different operating mode determines according to actual condition.

The described spaning middle section moment M corresponding to gravity calculating downlead _jzconcrete grammar be:

$M_{\mathrm{jz}}=\frac{G_{P}l}{4}+\frac{G_W(l-2s)}{4}-\frac{\mathrm{sc}{G}_W}{l+2c}$

Wherein, G _p, G _wthe gravity of two downleads respectively; S is the distance between two downleads, and q is the gravity of tube type bus unit length; L is the distance between tube type bus two hitch point; C is the distance between hitch point and tube type bus thread end.

Spaning middle section moment M corresponding during described calculating earthquake _ezconcrete grammar be:

$M_{\mathrm{ez}}=\frac{F_{1}l}{4}-\frac{F_{2}c}{2}-\frac{F_{3}c}{2}$

Wherein, F ₁, F ₂, F ₃, F ₄, F ₅being respectively is geological process power, and its active position is determined according to quality condensation methods.

The concrete grammar calculating tube type bus amount of deflection in described step 6 is:

Pipe, when re-computation, calculates mid-span deflection y ' _zg:

$y_{\mathrm{zg}}^{,}=\frac{{\mathrm{ql}}^2}{\mathrm{EJ}}(\frac{{5l}^2}{384}-\frac{c^2}{16})$

During downlead Gravity calculation, calculate mid-span deflection y ' _zj:

$y_{\mathrm{zj}}^{,}=\frac{1}{\mathrm{EJ}}[\frac{{\mathrm{Pl}}^3}{48}-\frac{l^2}{8}\frac{\mathrm{csW}}{l+2c}+\frac{W}{48}(l-2s)(l^2+2\mathrm{ls}-2s^2)]$

Synthesis mid-span deflection y ':

y’＝y’ _zg+y’ _zj

Wherein, q is the gravity of tube type bus unit length; L is the distance between tube type bus two hitch point; C is the distance between hitch point and tube type bus thread end, and E is tube type bus modulus of elasticity, and J is tube type bus cross sectional moment of inertia, and W is the section factor of tube type bus, and s is the distance between two downleads.

The invention has the beneficial effects as follows:

The inventive method has taken into full account the impact of DIFFERENT METEOROLOGICAL CONDITIONS factor on tube type bus, achieve the reasonable integration of electricity and mechanics, overcome in Practical Project the drawback only relying on electricity theory or experience to select single span suspention tube type bus, the method is single span suspention cast bus bar model selection system, comprehensive, reliable foundation, the arrangement of single span suspention tube type bus can be determined more accurately, reduce the error thinking that factor causes, improve the fail safe of producing, ensure the normal operation of transformer station.

Accompanying drawing explanation

Fig. 1 (a) is single span column pipe type bus force analysis figure under centralized load;

Fig. 1 (b) is single span column pipe type bus force analysis figure under earthquake;

Fig. 1 (c) is single span column pipe type bus force analysis figure under evenly load;

Embodiment:

Below in conjunction with accompanying drawing and embodiment, the present invention will be further described:

As shown in Fig. 1 (a), this figure mainly illustrates to suspend tube type bus in midair by stressing conditions during Concentrated load.In figure, W, P are centralized load point, and Q is counterweight point of load application.Column pipe is female can produce mid span moment and pulling force under W, P, Q effect, for the female stress of computer tube is prepared.

As shown in Fig. 1 (b), this figure mainly illustrates to suspend in midair the stressing conditions under tube type bus geological process.F in figure ₁, F ₂, F ₃for geological process power, according to quality polycondensation principle, force position can be thought and immobilizes.Honest the hang power of V suffered by the insulator string of suspention bus, column pipe is female can produce mid span moment and pulling force under seismic force effects, for the female stress of computer tube is prepared.

As shown in Fig. 1 (c), this figure mainly illustrates to suspend tube type bus in midair by stressing conditions during Uniform Load.In figure, q is evenly load, and column pipe is female can produce mid span moment under Uniform Load, for the female stress of computer tube is prepared.

In Fig. 1 (a) ~ Fig. 1 (c), the formula of calculated bending moment and the honest power of hanging is different.

Transformer station's suspention cast bus bar model selection method for arranging, comprises the following steps:

Step one: the span of initial setting tube type bus and spaced apart;

Step 2: selected certain model bus in alternative tube type bus;

Step 3: under determining various operating mode, the value of Fundamentals; Specifically comprise: about coefficient of safety and characteristic value of load value standard, the value value standard of wind factor, the value value standard of icing factor, the computational methods of short-circuit electromotive force, the computational methods of seismic force, tube type bus Load Combination condition, the maximum allowable stress of material and the deflection limit value of tubular conductor;

Step 4: gather the weight parameter of insulator string along the projected length parameter of tube type bus axis, the vertical projected length parameter of insulator string and insulator string respectively, under calculating deadweight and maximum wind velocity effect respectively, conduct oneself with dignity and under icing effect, short circuit and earthquake time tube type bus suffered by stress;

Step 5: suffered by the tube type bus calculated under judging above-mentioned often kind of situation, whether stress is all less than the maximum allowable stress of tube type bus, if so, goes to step six; If under having a kind of situation at least, suffered by tube type bus, stress is more than or equal to the maximum allowable stress of tube type bus, then traversal step two to step 4;

Step 6: calculate tube type bus amount of deflection;

Step 7: in determining step six, whether tube type bus amount of deflection is less than set point, if, determine that the model of tube type bus, span and spaced apart are respectively tube type bus model, span and the spaced apart set in step one and step 2, otherwise, traversal step two to step 6.

Wherein, under calculating deadweight and maximum wind velocity effect, the concrete steps of stress suffered by tube type bus are as follows:

(4-1) computer tube deadweight, the gravity of downlead, the spaning middle section moment of flexure corresponding to maximum wind velocity;

(4-2) pulling force of tube type bus is calculated;

(4-3) controlling sections moment of flexure is synthesized;

(4-4) according to synthesis section turn moment, tube type bus pulling force calculated stress and compared with maximum allowable stress;

Under calculating deadweight and icing effect, the concrete steps of stress suffered by tube type bus are as follows:

(6-1) computer tube deadweight, downlead gravity, ice load, icing time the spaning middle section moment of flexure corresponding to wind speed;

(6-2) pulling force of tube type bus is calculated;

(6-3) controlling sections moment of flexure is synthesized;

(6-4) according to synthesis section turn moment, tube type bus pulling force calculated stress and compared with maximum allowable stress;

Under calculating short circuit, suffered by tube type bus, the concrete steps of stress are as follows:

(8-1) computer tube deadweight, the gravity of downlead, short-circuit electromotive force, spaning middle section moment of flexure corresponding to 50% maximum wind velocity;

(8-2) pulling force of tube type bus is calculated;

(8-3) controlling sections moment of flexure is synthesized;

(8-4) according to synthesis section turn moment, tube type bus pulling force calculated stress and compared with maximum allowable stress;

During calculating earthquake, suffered by tube type bus, the concrete steps of stress are as follows:

(10-1) computer tube deadweight, the gravity of downlead, geological process, spaning middle section moment of flexure corresponding to 25% maximum wind velocity;

(10-2) pulling force of tube type bus is calculated;

(10-3) controlling sections moment of flexure is synthesized;

(10-4) according to synthesis section turn moment, tube type bus pulling force calculated stress and compared with maximum allowable stress;

In Practical Project, because the quantity of downlead is different, the quantity that the present invention may occur at in-depth analysis downlead, incorporation engineering application demand, have selected one more disadvantageous situation comparatively speaking, arranges study the type selecting of suspention tube type bus.

A, pipe when re-computation, according to formulae discovery spaning middle section moment M _gz:

$M_{\mathrm{Gz}}=q(\frac{l^2}{8}-\frac{c^2}{2})---\left(1\right)$

Wherein, q is the gravity (comprising strong wind, icing, Short-circuit Working Condition) of tube type bus line unit length; L is the distance between tube type bus two hitch point; C is the distance between hitch point and tube type bus thread end.

B, during downlead (gold utensil) Gravity calculation, according to formulae discovery spaning middle section moment M _jz:

$M_{\mathrm{jz}}=\frac{G_{P}l}{4}+\frac{G_W(l-2s)}{4}-\frac{\mathrm{sc}{G}_W}{l+2c}---\left(5\right)$

Wherein, G _p, G _wthe gravity of downlead; S is the distance between two downleads.

C, when seismic force calculates, according to formulae discovery spaning middle section moment M _dz:

$M_{\mathrm{dz}}=\frac{F_{1}l}{4}-\frac{F_{2}c}{2}-\frac{F_{3}c}{2}---\left(12\right)$

Wherein, F ₁, F ₂, F ₃, F ₄, F ₃geological process power.

D, calculates the spaning middle section moment M of synthesis respectively according to formula.

$M=\sqrt{M_s^2+M_c^2}---\left(19\right)$

Wherein, M _sit is the synthesis of all horizontal bending moments; M _cit is the synthesis of all vertical bending moment.

E, according to the pulling force R of formulae discovery tube type bus.

$R=\frac{h}{v}(\mathrm{PG}+\mathrm{PC})---\left(20\right)$

Wherein, h is the projected length of insulator string along tube type bus axis; V is the vertical projected length of insulator string; PG is the half of all vertical loads on tube type bus; PC is the gravity of going here and there and the gravity of going here and there the icing that may exist.

F, according to formula, by the pulling force R of bus, the spaning middle section moment M calculated stress of synthesis _σ;

$\mathrm{\σ}=\frac{M}{W}+\frac{R}{A}---\left(21\right)$

Wherein, W is the section factor of tube type bus; A is the area of section of tube type bus.

Respectively calculate deadweight and maximum wind velocity time stress, deadweight and icing time stress, short circuit time stress, earthquake time stress, if arbitrary calculated stress is greater than maximum allowable stress under these operating modes, then reselect tube type bus pattern, then continue calculating.

G, pipe when re-computation, according to formulae discovery mid-span deflection y ' _zg:

$y_{\mathrm{zg}}^{,}=\frac{{\mathrm{ql}}^2}{\mathrm{EJ}}(\frac{{5l}^2}{384}-\frac{c^2}{16})---\left(22\right)$

H, during downlead Gravity calculation, according to formulae discovery mid-span deflection y ' _zj:

$y_{\mathrm{zj}}^{,}=\frac{1}{\mathrm{EJ}}[\frac{{\mathrm{Pl}}^3}{48}-\frac{l^2}{8}\frac{\mathrm{csW}}{l+2c}+\frac{W}{48}(l-2s)(l^2+2\mathrm{ls}-2s^2)]---\left(23\right)$

I, according to formulae discovery synthesis mid-span deflection y ':

y’＝y’ _zg+y’ _zj (24)

If calculate amount of deflection to be greater than 0.5D (D is the diameter of tube type bus), then reselect tube type bus pattern, then continue to calculate.

By reference to the accompanying drawings the specific embodiment of the present invention is described although above-mentioned; but not limiting the scope of the invention; one of ordinary skill in the art should be understood that; on the basis of technical scheme of the present invention, those skilled in the art do not need to pay various amendment or distortion that creative work can make still within protection scope of the present invention.

Claims (10)

1. transformer station's single span suspention cast bus bar model selection method for arranging, is characterized in that, comprise the steps:

Step one: the span of initial setting tube type bus and spaced apart;

Step 2: selected certain model bus in alternative tube type bus;

Step 3: under determining various operating mode, the value of Fundamentals; Specifically comprise: about coefficient of safety and characteristic value of load value standard, the value value standard of wind factor, the value value standard of icing factor, the computational methods of short-circuit electromotive force, the computational methods of seismic force, tube type bus Load Combination condition, the maximum allowable stress of material and the deflection limit value of tubular conductor;

Step 4: gather the weight parameter of insulator string along the projected length parameter of tube type bus axis, the vertical projected length parameter of insulator string and insulator string respectively, under calculating deadweight and maximum wind velocity effect respectively, conduct oneself with dignity and under icing effect, short circuit and earthquake time tube type bus suffered by stress;

Step 5: suffered by the tube type bus calculated under judging above-mentioned often kind of situation, whether stress is all less than the maximum allowable stress of tube type bus, if so, goes to step six; If under having a kind of situation at least, suffered by tube type bus, stress is more than or equal to the maximum allowable stress of tube type bus, then traversal step two to step 4;

Step 6: calculate tube type bus amount of deflection;

Step 7: in determining step six, whether tube type bus amount of deflection is less than set point, if, determine that the model of tube type bus, span and spaced apart are respectively tube type bus model, span and the spaced apart set in step one and step 2, otherwise, traversal step two to step 6.

2. a kind of transformer station as claimed in claim 1 single span suspention cast bus bar model selection method for arranging, is characterized in that, in described step 4, calculating is conducted oneself with dignity and under maximum wind velocity effect, the concrete grammar of stress suffered by tube type bus is:

(4-11) the spaning middle section moment M corresponding to computer tube deadweight _gz; Calculate the spaning middle section moment M corresponding to gravity of downlead _jz; Calculate the spaning middle section moment M corresponding to maximum wind velocity _fz; Described maximum wind velocity, according to the difference in geographical position, gets the maximum of relevant position historical wind speed data;

(4-12) spaning middle section moment M is synthesized respectively according to the section turn moment of above-mentioned calculating ₁

$M_1=\sqrt{M_{\mathrm{fz}}^2+(M_{\mathrm{Gz}}^2+M_{\mathrm{jz}}^2)}$

(4-13) the pulling force R of tube type bus is calculated ₁;

$R_1=\frac{h}{v}(\mathrm{PG}+\mathrm{PC})$

In formula, h is the projected length of insulator string along tube type bus axis; V is the vertical projected length of insulator string; PG is the half of all vertical loads on tube type bus; PC is the gravity of insulator string;

(4-14) according to the pulling force R of tube type bus ₁with synthesis spaning middle section moment M ₁calculated stress σ ₁;

${\mathrm{\σ}}_1=\frac{M_1}{W}+\frac{R_1}{A};$

Wherein, W is the section factor of tube type bus; A is the area of section of tube type bus.

3. a kind of transformer station as claimed in claim 1 single span suspention cast bus bar model selection method for arranging, is characterized in that, in described step 4, calculating is conducted oneself with dignity and under icing effect, the concrete grammar of stress suffered by tube type bus is:

(4-21) the spaning middle section moment M corresponding to computer tube deadweight _gz; Calculate the spaning middle section moment M corresponding to gravity of downlead _jz; Spaning middle section moment M corresponding during calculating ice load _bz; Calculate the spaning middle section moment M corresponding to wind speed during icing _bfz;

(4-22) according to the section turn moment of above-mentioned calculating synthesis spaning middle section moment M ' ₁;

$M_1^{\′}=\sqrt{M_{\mathrm{bfz}}^2+(M_{\mathrm{Gz}}^2+M_{\mathrm{jz}}^2+M_{\mathrm{bz}}^2)}$

(4-23) the pulling force R of tube type bus is calculated ₂;

$R_2=\frac{h}{v}(\mathrm{PG}+\mathrm{PC})$

R ₂with R ₁computing formula difference is, different to the calculating value of PG.

(4-24) according to the pulling force R of tube type bus ₂with synthesis spaning middle section moment M ' ₁calculated stress σ ' ₁;

${{\mathrm{\σ}}^{\′}}_1=\frac{{M_1}^{\′}}{W}+\frac{R_2}{A};$

Wherein, W is the section factor of tube type bus; A is the area of section of tube type bus.

4. a kind of transformer station as claimed in claim 1 single span suspention cast bus bar model selection method for arranging, is characterized in that, in described step 4, during calculating short circuit, suffered by tube type bus, the concrete grammar of stress is:

(4-31) the spaning middle section moment M corresponding to computer tube deadweight _gz; Calculate the spaning middle section moment M corresponding to gravity of downlead _jz; Spaning middle section moment M corresponding during calculating short circuit _dz; Calculate the spaning middle section moment M corresponding to 50% maximum wind velocity _50%fz;

(4-32) according to the section turn moment synthesis spaning middle section moment M of above-mentioned calculating " ₁;

$M_1^{\′\′}=\sqrt{(M_{\mathrm{dz}}^2+M_{50\%\mathrm{fz}}^2)+(M_{\mathrm{Gz}}^2+M_{\mathrm{jz}}^2)}$

(4-33) the pulling force R of tube type bus is calculated ₃;

$R_3=\frac{h}{v}(\mathrm{PG}+\mathrm{PC})$

(4-34) according to the pulling force R of tube type bus ₃with synthesis spaning middle section moment M " ₁calculated stress σ " ₁;

${{\mathrm{\σ}}^{\′\′}}_1=\frac{{M_1}^{\′\′}}{W}+\frac{R_3}{A};$

Wherein, W is the section factor of tube type bus; A is the area of section of tube type bus.

5. a kind of transformer station as claimed in claim 1 single span suspention cast bus bar model selection method for arranging, is characterized in that, in described step 4, during calculating earthquake, suffered by tube type bus, the concrete grammar of stress is:

(4-41) the spaning middle section moment M corresponding to computer tube deadweight _gz;

Calculate the spaning middle section moment M corresponding to gravity of downlead _jz;

Spaning middle section moment M corresponding during calculating earthquake _ez;

Calculate the spaning middle section moment M corresponding to 25% maximum wind velocity _25%fz;

(4-42) according to the section turn moment synthesis spaning middle section moment M of above-mentioned calculating " ' ₁;

$M_1^{\′\′\′}=\sqrt{(M_{\mathrm{ez}}^2+M_{25\%\mathrm{fz}}^2)+(M_{\mathrm{Gz}}^2+M_{\mathrm{jz}}^2)}$

(4-43) the pulling force R of tube type bus is calculated ₄;

R ₄＝R ₁+R _V

R in formula _vfor the pulling force under Vertical Earthquake Loads.

(4-44) according to the pulling force R of tube type bus ₄with synthesis spaning middle section moment M " ' ₁calculated stress σ " ' ₁;

${{\mathrm{\σ}}^{\′\′\′}}_1=\frac{{M_1}^{\′\′\′}}{W}+\frac{R_4}{A};$

Wherein, W is the section factor of tube type bus; A is the area of section of tube type bus.

6. any one the transformer station's single span suspention cast bus bar model selection method for arranging as described in claim 1-5, is characterized in that, the spaning middle section moment M corresponding to described computer tube deadweight _gzmethod be:

$M_{\mathrm{Gz}}=q(\frac{l^2}{8}-\frac{c^2}{2})$

Wherein, q is the gravity of tube type bus line unit length; L is the distance between tube type bus two hitch point; C is the distance between hitch point and tube type bus thread end.

7. any one the transformer station's single span suspention cast bus bar model selection method for arranging as described in claim 1-5, it is characterized in that, the method of spaning middle section moment of flexure corresponding when wind speed when described calculating maximum wind velocity, ice load, icing, short circuit, 50% maximum wind velocity are conducted oneself with dignity with computer tube with the method for spaning middle section moment of flexure corresponding during 25% maximum wind velocity is identical, and the gravity q of the tube type bus unit length just under different operating mode determines according to actual condition.

8. any one the transformer station's single span suspention cast bus bar model selection method for arranging as described in claim 1-5, is characterized in that, the described spaning middle section moment M corresponding to gravity calculating downlead _jzconcrete grammar be:

$M_{\mathrm{jz}}=\frac{G_{P}l}{4}+\frac{G_W(l-2s)}{4}-\frac{\mathrm{sc}{G}_W}{l+2c}$

Wherein, G _p, G _wthe gravity of two downleads respectively; S is the distance between two downleads, and q is the gravity of tube type bus unit length; L is the distance between tube type bus two hitch point; C is the distance between hitch point and tube type bus thread end.

9. any one the transformer station's single span suspention cast bus bar model selection method for arranging as described in claim 1-5, is characterized in that, spaning middle section moment M corresponding during described calculating earthquake _ezconcrete grammar be:

$M_{\mathrm{ez}}=\frac{F_{1}l}{4}-\frac{F_{2}c}{2}-\frac{F_{3}c}{2}$

Wherein, F ₁, F ₂, F ₃, F ₄, F ₅being respectively is geological process power, and its active position is determined according to quality condensation methods.

10. any one transformer station's single span suspention cast bus bar model selection method for arranging as claimed in claim 1, it is characterized in that, the concrete grammar calculating tube type bus amount of deflection in described step 6 is:

Pipe, when re-computation, calculates mid-span deflection y ' _zg:

$y_{\mathrm{zg}}^{\′}=\frac{{\mathrm{ql}}^2}{\mathrm{EJ}}(\frac{{5l}^2}{384}-\frac{c^2}{16})$

During downlead Gravity calculation, calculate mid-span deflection y ' _zj:

$y_{\mathrm{zj}}^{\′}=\frac{1}{\mathrm{EJ}}[\frac{{\mathrm{Pl}}^3}{48}-\frac{l^2}{8}\frac{\mathrm{csW}}{l+2c}+\frac{W}{48}(l-2s)(l^2+2\mathrm{ls}-{2s}^2)]$

Synthesis mid-span deflection y ':

y′＝y′ _zg+y′ _zj

Wherein, q is the gravity of tube type bus unit length; L is the distance between tube type bus two hitch point; C is the distance between hitch point and tube type bus thread end, and E is tube type bus modulus of elasticity, and J is tube type bus cross sectional moment of inertia, and W is the section factor of tube type bus, and s is the distance between two downleads.