The mechanical effects of short-circuit currents in - Montefiore

Figure 6.3 Converter short-circuit current.
a without smoothing inductor
b with smoothing reactor
c with smoothing inductor
d with rapid-acting control, current limited to
100 A
Figure 6.4 Short-circuit current of fully charged lead-acid battery
with an open-circuit voltage of 25,2 V.
K10 indicates the current capacity for discharge
within 10 hours.
Figure 6.5 Capacitor short-circuit current. Capacitor voltage
before short circuit is 24 V.
99
Figure 6.6 Motor short-circuit current. Rated voltage 24 V, rated
current 31 A, moment of inertia of the motor JM,
overall moment of inertia Jg.
6.2.2. Standardised characteristics of short-circuit
currents and electromagnetic forces
As shown in Figure 6.7, the variety of short-circuit
current characteristics in d.c. systems [Ref 60, Ref 63,
Ref 66, Ref 67, Ref 68, Ref 69, Ref 70, Ref 71, Ref
72, Ref 73, Ref 74, Ref 75] may be approximated by
an exponential rise to the peak short-circuit current i p
and thereafter an exponential drop to the steady-state
short-circuit current I k.
Figure 6.7 Standardised approximation function for the shortcircuit
characteristic i(t) and for the electromagnetic
force per unit length F'(t). Variables ts1, ξs2 and ts will
be required in section 6.3.2.