Danfoss VLT AutomationDrive FC 301 Programming Manual page 455

VLT AutomationDrive FC 301/302
Programming Guide
Op- Name Description
tion
A
B
C
The DC level during [4] Kinetic backup equals parameter 14-11 Mains Fault Voltage Level x 1.35. If the mains does
not return, U
coasts. If the mains returns while in kinetic back-up mode, U
Voltage Level x 1.35. This is detected in 1 of the following ways:
•
If U
DC
• If the speed is above the reference. This is relevant if the 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 in point 1,
and the drive tries to reduce U
speed. This cannot be done as the mains cannot be lowered.
• If running mechanically. The same mechanism as in point 2 applies, but the inertia prevents the speed from
going above the reference speed. This leads to the motor running mechanically until the speed is above
the reference speed and the situation in point 2 occurs. Instead of waiting for that criterion, point 3 is intro-
duced.
[5] Kinetic The difference between kinetic back-up with and without trip is that the latter always ramps down to 0 RPM
back- and trips, regardless of whether mains returns or not. The function does not detect if mains returns. This is the
up, trip reason for the relatively high level on the DC link during ramp-down.
U [V]
DC
790 V
U
DC
SP-11*1.35
n [RPM]
Ref
0
Illustration 84: Kinetic Back-up Trip
A
B
[6] Alarm
[7] Kin. This option is valid in VVC+ only. Kinetic back-up with recovery combines the features of kinetic back-up and
back- kinetic back-up with trip. This feature makes it possible to select between kinetic back-up and kinetic back-up
up, trip with trip, based on a recovery speed, configurable in parameter 14-15 Kin. Back-up Trip Recovery Level. If mains
w re-
does not return, the drive ramps down to 0 RPM and trips. If mains returns while in kinetic back-up at a speed
covery
above the value in parameter 14-15 Kin. Back-up Trip Recovery Level, normal operation is resumed. This is equal
to [4] Kinetic Back-up. The DC level during [7] Kin. back-up, trip w recovery is parameter 14-11 Mains Fault Voltage
Level x 1.35.
U [V]
DC
U
DC
SP-11*1.35
n [RPM]
Ref
SP-15
Illustration 85: Kinetic Back-up Trip w/Recovery, Mains Returns Above Parameter 14-15 Kin. Back-up Trip Recovery Level
Danfoss A/S © 2022.12
Normal operation
Mains failure
Kinetic back-up
is maintained as long as possible by ramping the speed down towards 0 RPM. Finally, the drive
DC
> parameter 14-11 Mains Fault Voltage Level x 1.35 x 1.05.
to parameter 14-11 Mains Fault Voltage Level x 1.35 by increasing the
DC
A B C D
t [S]
t [S]
Normal operation
Mains failure
A B C D A E
t [S]
t [S]
Parameter Descriptions
D Mains return
E Normal operation: Ramping
increases above parameter 14-11 Mains Fault
DC
C Kinetic back-up
D Trip
AU275636650261en-000101 / 130R0334 | 455