Civil Engineering Reference
In-Depth Information
Fig. 7.11
An example of an industrial electric distribution line; see Table
7.2
for calculation
p
3
PMI
¼
V
I
n
cos
φ
The two different distribution lines examined are represented in Figs.
7.11
and
7.12
together with their equivalent series circuit RT, XT.
The basic assumptions for the calculation are as follows:
- The load voltage is kept constantly equal to the nominal value.
- The recorded active and reactive power upstream the distribution line (point 1)
in the site electrical substation are assumed as load powers. The load is taken to
be totally concentrated at the point most unfavorable for losses and voltage drop.
In a real situation the load is divided into many loads distributed along the line.
The calculation used gives the maximum losses.
- Voltage drop along the line, calculated with the simplified formula as given
above.
Results for the circuits illustrated in Figs.
7.11
and
7.12
are shown in Tables
7.2
and
7.3
.
Case 1 Active load power and reactive load power are the reference values which
have been recorded upstream the distribution line in normal operating conditions
(point 1).
