CN103675504B - Method for evaluating single-track bank section electrified railway lightning trip-out rate - Google Patents

Abstract

The invention discloses a method for measuring an electrified railway single-track bank section contact network lightning trip-out rate. The method comprises the steps of (1) obtaining electrified railway line parameters, (2) calculating the coordinates of lightning type dividing points and determining the influence areas of different lightning types of a contact network, (3) calculating an induction lightning trip-out rate, (4) calculating a back trip-out rate, (5) calculating a shielding failure trip-out rate, and (6) determining a total trip-out rate. The method is convenient to calculate, and a problem of the difficult calculation of the electrified railway lightning trip-out rate is solved.

Description

The method of evaluation and test single-track bank section electric railway tripping rate with lightning strike

Technical field

The present invention relates to a kind of method of measurement electric railway single-track bank segments contact net tripping rate with lightning strike, particularly It is related to a kind of based on electric geometry method calculating electric railway single-track bank segments contact net indirect lightning strike, counterattack, shielding jump The method of lock rate, it is adaptable to electric railway lightning Protection Design and Lightning Transformation, belongs to railway system's overvoltage field.

Background technology

Tractive power supply system lightning stroke trip has had a strong impact on the safe and stable operation of China's electric railway.To ensure train Reliability of operation, accurately calculates the tripping rate with lightning strike of contact net supply line, assesses its impact to traction power supply reliability, Often it needs to be determined that the tripping rate with lightning strike of contact net.At present, electrification railway contact net thunderbolt type is divided into indirect lightning strike and (is struck by lightning big Ground), counterattack (thunderbolt return wire, the grounded part such as post top portion), three kinds of shielding (thunderbolt carrier cable, contact line), conventional data Lacking these three tripping rate with lightning strike to electric railway carries out the accurate method for calculating, and is that China's electric railway has carried out being directed to Property ground lightning Protection Design and Lightning Transformation bring very big difficulty.

The content of the invention

It is an object of the invention to provide a kind of measurement electric railway single-track bank segments contact net tripping rate with lightning strike Method, using the method the year indirect lightning strike tripping operation of electric railway single-track bank segments contact net per 100 km can be calculated Rate, counterattack trip-out rate and back flash-over rate.

The present invention realizes that the know-why of above-mentioned purpose is to analyze electric railway single line using conventional electrical geometric model The indirect lightning strike of embankment segments contact net, counterattack, shielding situation, its principle is as shown in Figure 1.O is zero, respectively holding Power rope, backflow line position are the center of circle, and carrier cable is hit away from r with lightning leader_c, lightning leader hit away from r to return wire_gFor radius work Camber line, then the earth is hit away from r with lightning leader_eMake the straight line parallel to the earth, A, B, C point, wherein h are intersected at respectively_gFor backflow Line is to ground level, h_cBe carrier cable to ground level, a is distance of the carrier cable to post inboard, and b arrives post inboard for return wire Distance.Thunder and lightning hits ground when falling on the left of A points, now produces induced overvoltage on contact net high-voltage conducting wires, that is, sense Thunderbolt；When thunder and lightning falls in the middle of A, B, the return wire of contact net is hit at 2 points, produce on contact net high-voltage conducting wires and strikeed back electricity Pressure, that is, strike back；When thunder and lightning falls in the middle of B, C, contact net high-voltage conducting wires are hit at 2 points, shielding is produced on contact net excessively electric , that is, there is shielding in pressure；Thunder and lightning hits ground when falling on the right side of C points, induced overvoltage is produced on contact net high-voltage conducting wires, i.e., together There is indirect lightning strike in sample.

The technical solution adopted for the present invention to solve the technical problems is mainly included the following steps that：

The first step, obtains electric railway line parameter circuit value, including carrier cable, return wire are to ground level, carrier cable, return wire To the distance of post inboard, 50% impulse sparkover voltage of insulator chain, return wire radius, Thunderstorm Day, lightning strike density, insulator String average running voltage gradient, pillar earth resistance, pillar equivalent inductance, lightning current wave head time, corona correction coefficient, pillar Inductance in parallel value of both sides adjacent reflow line etc..

Second step, calculates the coordinate of separation A, B, C, determines the influence area of the different thunderbolt types of contact net.Set up such as Coordinate system shown in accompanying drawing 1, the corresponding coordinate of A points is (x_a, y_a), the corresponding coordinate of B points is (x_b, y_b), the corresponding coordinate of C points For (x_c, y_c).Now indirect lightning strike is corresponding interval for (- ∞, x_a) and (x_c,+∞), strike back corresponding interval for (x_a, x_b), around Hit corresponding interval for (x_b, x_c).According to the geometrical relationship of each point, each point coordinates is determined by following formula：

In formula：

λ₃=λ₂ ²+1

λ₄=2 λ₁λ₂-2h_c

λ₅=λ₁ ²+h_c ²-r_c ²

In formula：h_gIt is return wire to ground level (unit：M), h_cIt is carrier cable to ground level (unit：M), a is arrived for carrier cable Distance (the unit of post inboard：M), b is distance (unit of the return wire to post inboard：M), r_cIt is lightning leader to carrier cable Hit away from (unit：M), r_gReturn wire is hit away from (unit for lightning leader：M), r_eThe earth is hit away from (unit for lightning leader：m).

r_c、r_gCan be calculated using following empirical equation：

Or

In formula：I is amplitude of lightning current (unit：KA), h_cIt is carrier cable to ground level, h_gIt is return wire to ground level.

a₀、b₀、c₀Value can be carried out according to field experimentation or mimic buss experimental result, it is also possible to reference to power system Experience takes values below：

a₀=10, b₀=0.65；Or a₀=0.67, b₀=0.74, c₀=0.6；Or a₀=1.57, b₀=0.69, c₀= 0.45。

r_eCan be calculated as follows：

r_e=k₂r_c

Wherein k₂For striking distance factor, computing formula is as follows：

k₂=1.066+h_c/216.45

In formula：h_cIt is carrier cable to ground level.

Or k₂=22/h, or k₂=1.94-h/26, or k₂=1.08-h/59, or k₂=1.05-h/87.

In formula：H is strut height (unit：m).

To simplify calculating, r can be also made_c=r_g=r_e。

3rd step, calculates indirect lightning strike trip-out rate.

First, indirect lightning strike interval (- ∞, x are calculated according to following formula_a) and (x_c,+∞) effective projected length：

Wherein：

In formula：I is amplitude of lightning current, h_gIt is return wire to ground level, h_cIt is carrier cable to ground level, k₀For return wire with Geometrical coupling ratio between carrier cable, U_50%For 50% impulse sparkover voltage (unit of insulator chain：kV).

k₀Can be calculated as follows：

In formula：D ' is the distance (unit between carrier cable and return wire mirror image：M), d is the distance between carrier cable and return wire (unit：M), h_gBe return wire to ground level, r is return wire radius (unit：m).

Then, indirect lightning strike trip-out rate is calculated according to the following formula：

Wherein.For lightning strike density (unit：Secondary/km²My god), T_dFor Thunderstorm Day (unit：My god/year), f (I) it is probability of lightning current density, η is to build lonely rate.

F (I) may be used to lower empirical equation and be calculated：

Or

Or

Or

Or

Or

The calculating of η can be carried out as the following formula：

η=(4.5E^0.75-14)×10^-2

In formula：E is insulator chain average running voltage gradient (unit：kV/m).

Calculate the lower limit of integral I in indirect lightning strike trip-out rate formula_ea、I_ecDetermine as the following formula：

Wherein：

In formula：β be pillar diverting coefficient, R_iFor pillar earth resistance (unit：Ω), k is between return wire and carrier cable The coefficient of coup, L_tPillar equivalent inductance (unit：μ H), τ_fFor lightning current wave head time (unit：μs).

Wherein k=k₁k₀, k₁For corona correction coefficient, contact net desirable 1.15.

In formula：L_gFor the inductance in parallel value (unit of pillar both sides adjacent reflow line：μH).

Upper limit of integral I_maxAccording to the significance level or the specific requirement value of industry of circuit, it is also possible to be by distribution probability Amplitude of lightning current when 90% or 99% is estimated.

4th step, calculates according to the following formula counterattack trip-out rate：

Lower limit of integral I_g, upper limit of integral I_maxValue is ibid.

5th step, calculates according to the following formula back flash-over rate：

Lower limit of integral in formulaUpper limit of integral I_maxValue is ibid.

6th step, total tripping rate with lightning strike of contact net is indirect lightning strike trip-out rate, counterattack tripping rate with lightning strike and shielding thunderbolt Trip-out rate three's sum, i.e., calculate according to the following formula total trip-out rate：

N=n_gy+n_g+n_c

The solution have the advantages that and adopt electric geometry method, it is proposed that a kind of electric railway single-track bank section connects The indirect lightning strike of net-fault, counterattack, back flash-over rate computational methods, solve asking for electric railway tripping rate with lightning strike dyscalculia Topic.

Description of the drawings

The present invention is further illustrated with reference to the accompanying drawings and examples.

Fig. 1 is single-track bank segments contact net electric geometry method schematic diagram

Specific embodiment

Below by example, with reference to accompanying drawing 1, technical scheme is further described.

The first step, obtains line parameter circuit value.Certain railway single embankment section circuit, return wire distance to the ground 8m, carrier cable pair Ground level 7.8m, away from post inboard 3m, return wire is away from post inboard 0.8m, return wire radius 6.25mm, insulator for carrier cable U50% discharge voltage 270kV, the μ s of lightning current wave head time 2.6, Thunderstorm Day 40 days, insulator chain average running voltage gradient 20.36kV, the Ω of pillar earth resistance 10, the μ H of pillar equivalent inductance 6.72, the inductance in parallel value of pillar both sides adjacent reflow line 36.85 μ H, corona correction coefficient 1.15.

Calculate seasonAnd a₀=10, b₀=0.65；Choosing probability of lightning current density is

Second step, calculates indirect lightning strike, counterattack, back flash-over rate upper limit of integral and lower limit.

It is utilized respectively above-mentioned formula and calculates indirect lightning strike lower limit of integral I_ea、I_ecFor：

I_ea=58kA, I_ec=64kA.

Upper limit of integral I_maxAmplitude of lightning current when by distribution probability being 99% is estimated：

I_max=176kA

Calculate counterattack range of integration I_g、I_maxFor：

I_g=30kA, I_max=176kA.

Calculate shielding range of integration I_c、I_maxFor：

I_c=3kA, I_max=176kA.

3rd step, calculates indirect lightning strike trip-out rate.

Using A, B, C coordinate formula in indirect lightning strike lightning current bound interval range I_ea～I_max、I_ec～I_maxInterior calculating A, B, C coordinate is distributed, and determines indirect lightning strike valid interval, recycles following formula to calculate indirect lightning strike trip-out rate：

Result of calculation is n_gy=0.1230 time/100km.

4th step, calculates counterattack trip-out rate.

Using A, B, C coordinate formula in counterattack lightning current bound interval range I_g～I_maxIt is interior to calculate A, B, C coordinate point Cloth, it is determined that counterattack affects interval, recycles following formula to calculate counterattack trip-out rate：

Result of calculation is n_g=2.0259 times/100km.

5th step, calculates back flash-over rate.

Using A, B, C coordinate formula in shielding lightning current bound interval range I_c～I_maxIt is interior to calculate A, B, C coordinate point Cloth, determines that shielding affects interval, recycles following formula to calculate back flash-over rate：

Result of calculation is n_g=2.4638 times/100km.

6th step, using following formula total trip-out rate is calculated：

N=n_gy+n_g+n_c

Result of calculation is n=4.6127 time/100km.

Claims (2)

1. it is a kind of measurement electric railway single-track bank segments contact net tripping rate with lightning strike method, it is characterised in that it include with Lower step：

The first step, obtains electric railway line parameter circuit value, including carrier cable, return wire to ground level, and carrier cable, return wire are to propping up Distance on the inside of post, 50% impulse sparkover voltage of insulator chain, return wire radius, Thunderstorm Day, lightning strike density, insulator chain is put down Equal working voltage gradient, pillar earth resistance, pillar equivalent inductance, lightning current wave head time, corona correction coefficient, pillar both sides The inductance in parallel value of adjacent reflow line；

Second step, calculates the coordinate of separation A, B, C, and computing formula is as follows：

$\left\{\begin{array}{c}{x}_a=-\sqrt{{r_g}^2-{\left(r_e-h_g\right)}^2}-(a+b)\\ y_a=r_e\end{array}\right.$

$\left\{\begin{array}{c}{x}_b={\mathrm{\λ}}_1+{\mathrm{\λ}}_2\·\frac{-{\mathrm{\λ}}_4+\sqrt{{{\mathrm{\λ}}_4}^2-4{\mathrm{\λ}}_3{\mathrm{\λ}}_5}}{2{\mathrm{\λ}}_3}\\ y_b=\frac{-{\mathrm{\λ}}_4+\sqrt{{{\mathrm{\λ}}_4}^2-4{\mathrm{\λ}}_3{\mathrm{\λ}}_5}}{2{\mathrm{\λ}}_3}\end{array}\right.$

$\left\{\begin{array}{c}{x}_c=\sqrt{{r_c}^2-{(r_e-h_c)}^2}\\ y_c=r_e\end{array}\right.$

In formula：

${\mathrm{\λ}}_1=\frac{{r_g}^2-{r_c}^2+{h_c}^2-{h_g}^2-{\left(a+b\right)}^2}{2\left(a+b\right)}$

${\mathrm{\λ}}_2=\frac{h_g-h_c}{a+b}$

λ₃=λ₂ ²+1

λ₄=2 λ₁λ₂-2h_c

λ₅=λ₁ ²+h_c ²-r_c ²

In formula：h_gIt is return wire to ground level, unit：m；h_cIt is carrier cable to ground level, unit：m；A is carrier cable in pillar The distance of side, unit：m；B be return wire to post inboard distance, unit：m；r_cCarrier cable is hit away from single for lightning leader Position：m；r_gReturn wire is hit away from unit for lightning leader：m；r_eThe earth is hit away from unit for lightning leader：m；

3rd step, divides the region of different thunderbolt types, and the wherein region of induced lightening is (- ∞, x_a) and (x_c,+∞), it is right to strike back The region answered is (x_a, x_b), the corresponding region of shielding is (x_b, x_c)；

4th step, calculates according to the following formula indirect lightning strike trip-out rate：

Wherein：Υ=0.023T_d ^0.3For lightning strike density, unit：Secondary/km²My god；T_dFor Thunderstorm Day, unit：My god/year；F (I) is Probability of lightning current density, η is to build lonely rate, Δ L_a、ΔL_cFor effective projected length that indirect lightning strike is interval；

η computing formula are as follows：

η=(4.5E^0.75-14)×10^-2

In formula：E be insulator chain average running voltage gradient, unit：kV/m；

Probability of lightning current density f (I) computing formula is as follows：

$f\left(I\right)=0.026\×{10}^{-\frac{I}{88}}$

ΔL_a、ΔL_cComputing formula is as follows：

${\mathrm{\&Delta;L}}_a=\left\{\begin{array}{cc}{x}_a-x_{ea},& x_{ea}<x_a\\ 0,& x_{ea}\&GreaterEqual;x_a\end{array}\right.,{\mathrm{\&Delta;L}}_c=\left\{\begin{array}{cc}{x}_{ec}-x_c,& x_{ec}>x_c\\ 0,& x_{ec}\&le;x_c\end{array}\right.$

Wherein：

$x_{ea}=-\frac{I\&CenterDot;25h_c\left(1-k_0\frac{h_g}{h_c}\right)}{U_{50\%}},x_{ec}=\frac{I\&CenterDot;25h_c\left(1-k_0\frac{h_g}{h_c}\right)}{U_{50\%}}$

In formula：I is amplitude of lightning current, unit：KA, h_gIt is return wire to ground level, h_cIt is carrier cable to ground level, k₀For backflow Geometrical coupling ratio between line and carrier cable, U_50%For 50% impulse sparkover voltage of insulator chain, unit：kV；

k₀It is calculated as follows：

$k_0=\frac{\ln \frac{d^{\&prime;}}{d}}{\ln \frac{2h_g}{r}}$

In formula：D ' is the distance between carrier cable and return wire mirror image, unit：m；D is the distance between carrier cable and return wire, single Position：m；h_gBe return wire to ground level, r is return wire radius, unit：m；

Calculate the lower limit of integral I in indirect lightning strike trip-out rate formula_ea、I_ecDetermine as the following formula：

$I_{ea}=\frac{U_{50\%}\left|x_{ag}\right|}{25h_c(1-k_0\frac{h_g}{h_c})},I_{ec}=\frac{U_{50\%}\left|x_{cg}\right|}{25h_c(1-k_0\frac{h_g}{h_c})}$

Wherein：

$x_{ag}=\sqrt{{\left(10{I_g}^{0.65}\right)}^2-{\left(10{I_g}^{0.65}-h_g\right)}^2}-\left(a+b\right),x_{cg}=\sqrt{{\left(10{I_g}^{0.65}\right)}^2-{\left(10{I_g}^{0.65}-h_c\right)}^2}$

$I_g=\frac{U_{50\%}}{(1-k){\mathrm{\&beta;R}}_i+(\frac{h_g}{h_c}-k)\mathrm{\&beta;}\frac{L_t}{{\mathrm{\&tau;}}_f}+(1-\frac{h_g}{h_c}{k}_0)\frac{h_c}{{\mathrm{\&tau;}}_f}}$

In formula：β be pillar diverting coefficient, R_iFor pillar earth resistance, unit：Ω；K is the coupling between return wire and carrier cable Coefficient, L_tFor pillar equivalent inductance, unit：μH；τ_fFor lightning current wave head time, unit：μs；

Wherein k=k₁k₀, k₁For corona correction coefficient, contact net takes 1.15；

$\mathrm{\&beta;}=1/(1+\frac{L_t}{L_g}+\frac{R_i{\mathrm{\&tau;}}_f}{2L_g})$

In formula：L_gFor the inductance in parallel value of pillar both sides adjacent reflow line, unit：μH；

Upper limit of integral I_maxAccording to the significance level or the specific requirement value of industry of circuit, or by distribution probability be 90% or Amplitude of lightning current when 99% is estimated；

5th step, calculates according to the following formula counterattack tripping rate with lightning strike：

Lower limit of integral I_g, upper limit of integral I_maxValue is ibid；

6th step, calculates according to the following formula back flash-over rate：

Lower limit of integral in formulaUpper limit of integral I_maxValue is ibid；

7th step, calculates according to the following formula the total tripping rate with lightning strike of contact net：

N=n_gy+n_g+n_c

In formula：n_gyFor indirect lightning strike trip-out rate, n_gTo strike back tripping rate with lightning strike, n_cFor back flash-over rate.

2. a kind of method according to claim 1, wherein hitting away from r in separation A, B, C coordinates computing formula_c、r_gTo Lower empirical equation is calculated：

$r_c=r_g=a_0{I}^{b_0}$

Or

In formula：I is amplitude of lightning current, unit：kA；h_cIt is carrier cable to ground level, unit：m；h_gBe return wire to ground level, it is single Position：m；

a₀、b₀、c₀Value is carried out according to field experimentation or mimic buss experimental result, or with reference to power system experience take it is following Numerical value：

a₀=10, b₀=0.65；Or a₀=0.67, b₀=0.74, c₀=0.6；Or a₀=1.57, b₀=0.69, c₀=0.45；

r_eIt is calculated as follows：

r_e=k₂r_c

Wherein k₂For striking distance factor, computing formula is as follows：

k₂=1.066+h_c/216.45

In formula：h_cIt is carrier cable to ground level；

Or k₂=22/h, or k₂=1.94-h/26, or k₂=1.08-h/59, or k₂=1.05-h/87；

In formula：H is strut height, unit：m；

Or to simplify calculating, make r_c=r_g=r_e。