Danfoss VLT AutomationDrive FC 302 Programming Manual page 70

Parameter Descriptions
Speed
Ramp (X) S-Ramp
Ratio at Accel.End
3 3
Ramp (X) Linear
S-Ramp
Ratio at
Accel.End
Illustration 3.26 Linear Ramping Times
3-40 Ramp 1 Type
Option:
[0] Linear
*
[1] S-ramp
Const Jerk
[2] S-ramp
Const
Time
NOTICE
If [1] S-ramp Const Jerk is selected and the reference
during ramping is changed the ramp time may be
prolonged to realise a jerk-free movement, which may
result in a longer start or stop time.
Additional adjustment of the S-ramp ratios or switching
initiators may be necessary.
3-41 Ramp 1 Ramp Up Time
Range:
Size [ 0.01
related - 3600
*
s]
3-42 Ramp 1 Ramp Down Time
Range:
Size [ 0.01
related - 3600
*
s]
68
VLT
Ramp (X) S-Ramp
Ratio at Dec.End
Jerk compensated
Ramp (X)
Ramp (X)
Up Time
Down Time
Function:
Select the ramp type, depending on
requirements for acceleration/deceleration.
A linear ramp gives constant acceleration
during ramping. An S-ramp gives non-linear
acceleration, compensating for jerk in the
application.
Acceleration with lowest possible jerk.
S-ramp based on the values set in
parameter 3-41 Ramp 1 Ramp Up Time and
parameter 3-42 Ramp 1 Ramp Down Time.
Function:
Enter the ramp-up time, i.e. the acceleration
time from 0 RPM to the synchronous motor
speed n . Select a ramp-up time such that
S
the output current does not exceed the
current limit in parameter 4-18 Current Limit
during ramping. The value 0.00 corresponds
to 0.01 s in speed mode. See ramp-down
time in parameter 3-42 Ramp 1 Ramp Down
Time.
tacc s x ns RPM
Par . 3 − 41 =
ref RPM
Function:
Enter the ramp-down time, that is, the
deceleration time from the synchronous
®
AutomationDrive FC 301/302 Programming Guide
3-42 Ramp 1 Ramp Down Time
Range:
Ramp (X)
S-Ramp
Ratio at
Dec.End
3-45 Ramp 1 S-ramp Ratio at Accel. Start
Range:
50 % [ 1 - 99
*
%]
3-46 Ramp 1 S-ramp Ratio at Accel. End
Range:
50 % [ 1 - 99
*
%]
3-47 Ramp 1 S-ramp Ratio at Decel. Start
Range:
50 % [ 1 - 99
*
%]
3-48 Ramp 1 S-ramp Ratio at Decel. End
Range:
50 % [ 1 - 99
*
%]
MG33MI02 - Rev. 2013-11-20
Function:
motor speed n to 0 RPM. Select a ramp-
s
down time such that no overvoltage arises
in the inverter due to regenerative operation
of the motor, and such that the generated
current does not exceed the current limit set
in parameter 4-18 Current Limit. The value
0.00 corresponds to 0.01 s in speed mode.
See ramp-up time in parameter 3-41 Ramp 1
Ramp Up Time.
tdec s x ns RPM
Par . 3 − 42 =
ref RPM
Function:
Enter the proportion of the total ramp-up time
(parameter 3-41 Ramp 1 Ramp Up Time) in
which the acceleration torque increases. The
larger the percentage value, the greater the
jerk compensation achieved, and thus the
lower the torque jerks occurring in the
application.
Function:
Enter the proportion of the total ramp-up time
(parameter 3-41 Ramp 1 Ramp Up Time) in
which the acceleration torque decreases. The
larger the percentage value, the greater the
jerk compensation achieved, and thus the
lower the torque jerks in the application.
Function:
Enter the proportion of the total ramp-down
time (parameter 3-42 Ramp 1 Ramp Down Time)
where the deceleration torque increases. The
larger the percentage value, the greater the
jerk compensation achieved, and thus the
lower the torque jerks in the application.
Function:
Enter the proportion of the total ramp-down
time (parameter 3-42 Ramp 1 Ramp Down Time)
where the deceleration torque decreases. The
larger the percentage value, the greater the
jerk compensation achieved, and thus the
lower the torque jerks in the application.