Mathcad - HW 3 - University of · PDF fileX'C 1 ω⋅C1:= X'C 3.255 10 8 = ×...
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Transcript of Mathcad - HW 3 - University of · PDF fileX'C 1 ω⋅C1:= X'C 3.255 10 8 = ×...
εo 8.854 10 12−⋅:=4.32
f 60:= d 1.51100
⋅:= cm D 0.5:= meter ω 2 π⋅ f⋅:=
Cn2 π⋅ εo⋅
lnDd
2
⎛⎜⎜⎝
⎞⎟⎟⎠
:= Cn 1.325 10 11−×= F/m to neutral
Yn j ω⋅ Cn⋅ 1000⋅:= Yn 4.994i 10 6−×= S/km to neutral
4.39
Deq3 8 8⋅ 16⋅:= Deq 10.079= meter
From Table A.4 (Cardinal) r1.1962
0.0254⋅:= r 0.01519= meter
C12 π⋅ εo⋅
lnDeqr
⎛⎜⎝
⎞⎟⎠
:= C1 8.562 10 12−×=
Y1 j ω⋅ C1⋅ 1000⋅:= Y1 3.228i 10 6−×= S/km
VL 230000:= VLNVL
3:=
For a 100 km line length: Ichg Y1 VLN⋅:=
Ichg 0.429= per phase
4.46 part a
Deq3 12 12⋅ 24⋅:= Deq 15.119= r
0.03282
:= r 0.0164=
C12 π⋅ εo⋅
lnDeqr
⎛⎜⎝
⎞⎟⎠
:= C1 8.149 10 12−×=
X'C1
ω C1⋅:= X'C 3.255 108×= ohm-meter
For 125 km L 125000:= XCX'CL
:= XC 2.604 103×=
4.46 part b
H1 40:= H2 H1:= H3 H1:= H12 402 122+:= H21 H12:= H12 41.761=
H31 402 242+:= H31 46.648= H23 H12:=
X'C 3.255 108×=X'C2.8660
109⋅ lnDeqr
⎛⎜⎝
⎞⎟⎠
13lnH12 H23⋅ H31⋅
H1 H2⋅ H3⋅
⎛⎜⎝
⎞⎟⎠
⋅−⎛⎜⎝
⎞⎟⎠
⋅:=
XCX'C125000
:= XC 2.573 103×=