Safety information
20
Operating instructions SVCD(S)
123456278
-
419A58
Elektrotechnische Anlagen GmbH
1
Operation on a transformer
If only a few loads operate within a network section the connected transformer must be
able to transport the in this section not used power back to the next voltage level without
producing a not allowed voltage increase inside the section. Therefore the nominal power
of the transformer has to be one and a half higher than the backfed power out of the sec-
tion, so that also the harmonic and reactive components of the current can be transmitted.
In the network section displayed in figure 3.4.2 these conditions are checked up, even if
the other loads are switched off.
Is the backfed power in the order of the nominal power of the transformer, it's impedance
voltage has to be small enough (max. 6%) to limit the voltage increase in the section.
The operation of the power feedback unit in combination with an adjusting transformer
(e.g. in the case of a braked slip-ring induction motor) is only allowed, if the quotient ra-
tio of feedback-power and nominal power is much smaller than one
M
M
R
Tr
10kV
0,4kV
100kVA
60kW
20kW
20kW
FC
REVCON
Figure 2.6.2