雷击杆塔顶时耐雷水平的计算

雷击杆塔顶时耐雷水平的计算

I1：雷击杆塔顶时的耐雷水平；kA

U50％：绝缘子串50％冲击放电电压；kV

k：导线与地线间的耦合系数；k＝k1×k0

k1：电晕校正系数；查表2-7-9

k0：导线和地线间的几何耦合系数；查表2-7-8

β：杆塔分流系数；查表2-7-4

R su：杆塔冲击接地电阻；Ω

h a：横担对地高度；m

h t：杆塔高度；m

L t：杆塔电感；μH

h gv：地线的平均高度；m

h av：导线的平均高度；m

P1:超过雷电流幅值I1的概率；logP1=-I1/88

I2：雷绕击导线时的耐雷水平；kA；I2=U50％/100

P2:超过雷电流幅值I2的概率；logP2=-I2/88

b：两根地线之间的距离；m

N：每年每100km线路的雷击次数；N=0.28(b+4h av)

η：建弧率；η=(4.5E0.75-14)×10-2

g:击杆率；查表2-7-2

θ：杆塔上地线对外侧导线的保护角；°

Pθ：平原线路绕击率；lgPθ=θ×(h)0.5/86-3.9

Pθ'：山区线路绕击率；lgPθ'=θ×(h)0.5/86-3.35

h：地线在杆塔上的悬挂点高度；m

P3：雷击档距中央的避雷线时，雷电流超过耐雷水平的概率。由于发生这种闪络的情况极少，其值一般可

U（kV）n k1k0kβR su h a h t L t h1f1h gv h2f2 12022 1.250.2370.296250.881027381924818.673813

12016 1.250.2370.296250.881227381924818.673813

12016 1.250.2370.296250.881427381924818.673813

12016 1.250.2370.296250.881627381924818.673813

12016 1.250.2370.296250.881827381924818.673813

12016 1.250.2370.296250.882027381924818.673813 12016 1.250.2370.296250.882227381924818.673813 12016 1.250.2370.296250.882427381924818.673813 12016 1.250.2370.296250.882627381924818.673813 12016 1.250.2370.296250.882827381924818.673813 12016 1.250.2370.296250.883027381924818.673813 12016 1.250.2370.296250.883227381924818.673813 12016 1.250.2370.296250.883427381924818.673813

的情况极少，其值一般可不予计算。

h av I1P1I2P2b Nηg2平原g2山区θ

28.83144.710.02326.40.501622.590.5290.1670.2510

28.8398.550.07619.20.605622.590.5290.1670.2510

28.8392.660.08919.20.605622.590.5290.1670.2510

28.8387.430.10119.20.605622.590.5290.1670.2510

28.8382.770.11519.20.605622.590.5290.1670.2510

28.8378.570.12819.20.605622.590.5290.1670.2510 28.8374.780.14119.20.605622.590.5290.1670.2510 28.8371.340.15519.20.605622.590.5290.1670.2510 28.8368.200.16819.20.605622.590.5290.1670.2510 28.8365.330.18119.20.605622.59 1.5290.1670.2510 28.8362.680.19419.20.605622.59 2.5290.1670.2510 28.8360.250.20719.20.605622.59 3.5290.1670.2510 28.8357.990.21919.20.605622.59 4.5290.1670.2510

PθP

θ'P

3

n平n山

5E-040.00200.050.08 5E-040.00200.150.24 5E-040.00200.180.28 5E-040.00200.210.31 5E-040.00200.230.35

5E-040.00200.260.39 5E-040.00200.280.43 5E-040.00200.310.47 5E-040.00200.340.51 5E-040.0020 1.05 1.60 5E-040.0020 1.86 2.83 5E-040.0020 2.77 4.20 5E-040.0020 3.77 5.71