Politechnika Rzeszowska
Wydział Elektrotechniki i informatyki
Katedra Energoelektroniki i Elektroenergetyki
Calculation of parameters of long transmission line
Project 1 from subject Transmission of electricity
Name and surname: ŁUKASZ ZYCH L5 EN-DI
Academic year: 2013/2014
Deadline: 21.11.2013
Consider the 400 kV overhead power lines with a length of 200 km (tower is shown on Figure below). At the end of the line, assume a constant voltage U2 = 400 kV.
Parameters of phases conductors:
- type of conductor: 6x3xAlFe 445/74 (triple bundle conductor)
- diameter of conductor: dp = 29,63 mm,
- specific resistance of conductor: 0,0368 W.mm2.m-1
- conductance of conductor per 1 km of the length: G1 =2,5.10-8 S/km
- maximal sag of conductor: fp = 9 m.
Parameters of ground conductors:
- type of conductor: AlFe 185/31
- diameter of conductor: dg = 19,08 mm,
- maximal sag of conductor fg = 8 m.
U1
load
U2
l = 200 km
1) calculate the electrical parameters of the line: resistance (R), inductance L, capacitance (C), conductance (G)
2) draw the magnitude of:
- voltage,
- current,
- active power,
- reactive power.
along the line, i.e. U=f(x), I=f(x), P=f(x), Q=f(x) for cases, where the line is loaded with:
a) natural power (surge impedance loading)
b) 2 x natural power
c) 0,5 x natural power
d) 0 MW, 0 MVAr (no load).
3) calculate active power losses for cases a), b), c), d) in point 2)
Rozwiązanie:
a1-2= 4,5 [m]
a1-3= 4,5 [m]
a2-3= 3,7 [m]
a1-5= 12,4 [m]
a1-6= 8,9 [m]
a2-6= 9,8 [m]
a1-4= 9,8 [m]
a2-5= 13,5 [m]
a3-6= 6,1 [m]
1.Obliczenie rezystancji (R):
R=ρls Ω
R=0,0368Ωmm2m*200 000 mπ29,632mm2=10,64 Ω
2.Obliczenie induktancji (L):
L1km=0,46*log(aśrre)+0,05m mHkm
re=nrd12
re=329,632mm*400mm*400mm=128 [mm] 0,128m
aśr=3a12*a13*a23*3a15*a16*a263a14*a25*a36
aśr=34,1m*4,5m*3,7m*311,4m*8,9m*9,8m 39,8m*13,5m*6,1m = 4,36 [m]
L1km=0,46*log(4,36m0,128m)+0,053 =0,78mHkm
L=L1km*l
L=0,78mHkm*200 km=156 mH
3.Obliczenie pojemności (C):
C1=1N-N'=1(δ+δN)-(δ'-δN')
δ=10,0242*log(2hśrre) kmµF
hśr=3h1*h2*h3 [m]
hśr=317,6m*13,5m*13,5m= 14,8m
h1=h1 '-23 fp=22,9m-23 *8m=17,6 [m]
h2 =h3=h2'-23fp=18,8 m- 23 *8m=13,5[m] δ=10,0242*log2*14,8[m]0,128[m]=82,7kmµF δ'=10,0242*...
lukaszzychzych