Programming Guide | VLT® AutomationDrive FC 360
Option Name Description
[4] Kinetic back-up Kinetic back-up ensures that the drive
keeps running as long as there is energy in
the system due to the inertia from motor
and load. This is done by converting
the mechanical energy to the DC link
and thereby maintaining control of the
drive and motor. This can extend the
controlled operation, depending on the
inertia in the system. For fans, it is typically
several seconds, for pumps up to 2 s and
for compressors only for a fraction of a
second. Many industry applications can
extend controlled operation for many
seconds, which is often enough time for
the mains to return.
The DC-level during [4] Kinetic back-up
is parameter 14-11 Mains Fault Voltage
Level x 1.35. If the mains does not return,
UDC is maintained as long as possible by
ramping the speed down towards 0 RPM.
Finally, the drive coasts.
If mains returns while in kinetic back-up,
UDC increases above parameter 14-11
Mains Fault Voltage Level x 1.35. This is
detected in 1 of the following ways:
• If UDC >parameter 14-11 Mains Fault
Voltage Level x 1.35 x 1.05.
• If the speed is above the reference. This
is relevant if mains comes back at a
lower level than before, for example,
parameter 14-11 Mains Fault Voltage
Level x 1.35 x 1.02. This does not fulfill
the criterion above, and the drive tries
to reduce UDC to parameter 14-11
Mains Fault Voltage Level x 1.35 by
increasing the speed. This does not
succeed as mains cannot be lowered.
• If running motoric. The same
mechanism as in the previous point,
but where the inertia avoids the speed
from going above the reference speed.
This leads to the motor running motoric
until the speed is above the reference
speed, and the above situation occurs.
Instead of waiting for that, the present
criterion is introduced.
Danfoss A/S © 2024.01 AU275649936274en-001401 / 130R0507 | 233
To Next Page
Loading...
