Danfoss VLT AutomationDrive FC 301 Programming Manual page 67

Parameter Descriptions
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.
3-51 Ramp 2 Ramp Up Time
Range: Function:
Size Enter the ramp-up time, i.e. the acceleration
related [ 0.01 time from 0 RPM to the rated motor speed n
*
- 3600
Select a ramp-up time such that the output
s] current does not exceed the current limit in
4-18 Current Limit during ramping. The value
0.00 corresponds to 0.01 s in speed mode.
See ramp-down time in 3-52 Ramp 2 Ramp
Down Time.
Par . 3 − 51 =
3-52 Ramp 2 Ramp Down Time
Range: Function:
Size Enter the ramp-down time, i.e. the
related [ 0.01 deceleration time from the rated motor speed
*
- 3600 n to 0 RPM. Select a ramp-down time such
s
s]
that no overvoltage arises in the frequency
converter due to regenerative operation of the
motor, and such that the generated current
does not exceed the current limit set in
4-18 Current Limit. The value 0.00 corresponds
to 0.01 s in speed mode. See ramp-up time in
3-51 Ramp 2 Ramp Up Time.
Par . 3 − 52 =
3-55 Ramp 2 S-ramp Ratio at Accel. Start
Range: Function:
50 % [ 1 - Enter the proportion of the total ramp-up time
*
99 %] (3-51 Ramp 2 Ramp Up Time) in which the
acceleration torque increases. The larger the
percentage value, the greater the jerk compen-
sation achieved, and thus the lower the torque
jerks in the application.
3-56 Ramp 2 S-ramp Ratio at Accel. End
Range: Function:
50 % [ 1 - Enter the proportion of the total ramp-up time
*
99 %] (3-51 Ramp 2 Ramp Up Time) in which the
acceleration torque decreases. The larger the
percentage value, the greater the jerk compen-
sation achieved, and thus the lower the torque
jerks in the application.
®
VLT AutomationDrive FC 301/302 Programming Guide
s
t acc s x n s RPM
ref RPM
t dec s x n s RPM
ref RPM
MG33MH02 - Rev. 2013-09-30
3-57 Ramp 2 S-ramp Ratio at Decel. Start
Range: Function:
50 % [ 1 - Enter the proportion of the total ramp-down
*
99 %] time (3-52 Ramp 2 Ramp Down Time) where the
deceleration torque increases The larger the
percentage value, the greater the jerk compen-
sation achieved, and thus the lower the torque
jerks in the application.
3-58 Ramp 2 S-ramp Ratio at Decel. End
Range: Function:
50 % [ 1 - Enter the proportion of the total ramp-down
*
.
99 %] time (3-52 Ramp 2 Ramp Down Time) where the
deceleration torque decreases. The larger the
percentage value, the greater the jerk compen-
sation achieved, and thus the lower the torque
jerks in the application.
3.5.5 3-6* Ramp 3
Configure ramp parameters, see 3-4* Ramp 1.
3-60 Ramp 3 Type
Option: Function:
Select the ramp type, depending on
requirements for acceleration and deceleration.
A linear ramp gives constant acceleration
during ramping. An S-ramp gives non-linear
acceleration, compensating for jerk in the
application.
[0] Linear
*
[1] S-ramp Accelerates with lowest possible jerk.
Const Jerk
[2] S-ramp S-ramp based on the values set in 3-61 Ramp 3
Const Time Ramp up Time and 3-62 Ramp 3 Ramp down
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.
3-61 Ramp 3 Ramp up Time
Range: Function:
Size [ 0.01 Enter the ramp-up time, i.e. the
related - 3600 acceleration time from 0 RPM to the rated
*
s] motor speed n
such that the output current does not
exceed the current limit in 4-18 Current
Limit during ramping. The value 0.00
corresponds to 0.01 s in speed mode. See
. Select a ramp-up time
s
65
3 3