Kinetic Buffering (Vdc_Min Controller) - Siemens MICROMASTER 440 Operating Instructions Manual

Issue 10/03
3.17.2

Kinetic buffering (Vdc_min controller)

Parameter range:
Warnings
Faults
Function chart number:
Brief line supply failures can be buffered using the kinetic buffering function
(enabled using P1240). Line supply failures are buffered using the kinetic energy
(i.e. moments of inertia) of the driven load. In this case the prerequisite is that the
driven load has a sufficiently high moment of inertia - i.e. has sufficient kinetic
energy.
Using this technique, the frequency is controlled (closed-loop), so that energy is fed
to the drive inverter from the regenerating motor thus covering the system losses.
The losses during the line supply failure still remain which means that the motor
speed decreases. When using kinetic buffering it has to be taken into consideration
that the motor speed reduces.
100 %
P1245
V
KIB active
r0056
Bit 15
Fig. 3-63
When the line supply returns, the energy feed is again from the line side and the
output frequency of the drive inverter returns to the selected setpoint along the
ramp defined by the ramp-function generator.
MICROMASTER 440 Operating Instructions
6SE6400-5AW00-0BP0
P1240
r0056 bit 15
P1245, r1246, P1247
P1250 – P1253
P1256, P1257
A0503
F0003
FP4600
V
DC
Power failure
dc_min
1
0
I I
f
f
1
f
2
Kinetic buffering (Vdc_min controller)
3 Functions
2 ⋅ P 0210
P1245
⋅ ⋅
2 P 0210
100
5 %
Power restoration
t
t
f -
f
1 2
= ⋅
P1120
t
b
P1082
t
t
b
151