ABB COM600 series User's & Technical Manual page 29

1MRS758734 COM600 series 5.1
Substation Analytics Technical Manual
Table 4.3-2 Positive-sequence impedance values for typical 10/20 kv conductors,
"Flat" tower configuration assumed
Name
Al/Fe 36/6 Sparrow
Al/Fe 54/9 Raven
Al/Fe 85/14 Pigeon
Al/Fe 93/39 Imatra
Al/Fe 108/23 Vaasa
Al/Fe 305/39 Duck
Table 4.3-3 Positive-sequence impedance values for typical 33kv conductors,
"Flat" tower configuration assumed
Name
ACSR 50 sq.mm
ACSR 100 sq.mm
ACSR 500 sq.mm
Positive-sequence impedance values
An accurate fault localization requires good setting values for line impedances. As
datasheet impedance per unit values are valid only for a certain tower configuration, the
values should be adjusted according to the actual installation configuration. This minim-
izes the fault localization errors caused by inaccurate settings.
The positive-sequence reactance per unit and per phase can be calculated with a certain
approximation equation which applies to symmetrically transposed threephase aluminum
overhead lines without ground wires.
Figure 4.3-24 (Equation 15)
the geometric average of phase distances [m]
R1 [Ω/km]
0.915
0.578
0.364
0.335
0.287
0.103
R1 [Ω/km]
0.529
0.394
0.0548
X1 [Ω/km]
0.383
0.368
0.354
0.344
0.344
0.314
X1 [Ω/km]
0.444
0.434
0.346
equation_15.png
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