Control and Design of Microgrid Components - Power Systems ...

o
r
1
= 0.3277 Ω
= 0.0547 Ω
x
x
1
o
= 0.0121Ω
= 0.0072 Ω
impedances Z4 is 25 yd long:
r o
r
1
= 0.1092 Ω
= 0.0182 Ω
x
x
1
o
= 0.0040 Ω
= 0.0024 Ω
The neutral cable, or fourth wire, is one size bigger that the phase conductors as it is typically
sized in applications and runs all along the cables represented with impedance Z2, Z3 and Z4.
The size is AWG 2 and the parameters per unit of length are:
R
R
o
1
= 6.99 Ω / mi
= 0.987 Ω / mi
X
X
1
o
= 0.293 Ω / mi
= 0.165 Ω/
mi
The impedance of the neutral cable on each of the sections is as follow:
Z2n, 20 ft long:
r
o
= 0.0265 Ω
r = 0.0037 Ω
1
x
x
o
1
= 0.0010 Ω
= 0.00062 Ω
Z3n, 75 yd long:
r o
r
1
= 0.2979 Ω
= 0.0421Ω
x
x
1
o
= 0.0125 Ω
= 0.0070 Ω
Z4n, 25yd long:
r o
r
1
= 0.0993 Ω
= 0.0140 Ω
x
x
o
1
= 0.0042 Ω
= 0.0023 Ω
Table 6.2 summarizes all the useful data relevant to the cables in the system.
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