Danfoss FC 300 Programming Manual page 58

Parameter Descriptions
3-60 Ramp 3 Type
Option:
[2] S-ramp
Const Time
3 3
NOTE
If S-ramp [1] is selected and the reference during
ramping is changed the ramp time may be prolonged in
order to realize 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:
Application
dependent tion
*
dependant]
3-62 Ramp 3 Ramp down Time
Range:
Applica-
tion [Applica-
depend- tion
ent depend-
*
ant]
3-65 Ramp 3 S-ramp Ratio at Accel. Start
Range:
50 % [Application
*
dependant]
58
Function:
S-ramp based on the values set in
par. 3-61 Ramp 3 Ramp up Time and
par. 3-62 Ramp 3 Ramp down Time
Function:
[Applica- Enter the ramp-up time, i.e. the acceler-
ation time from 0 RPM to the rated
motor speed n . Choose a ramp-up time
s
such that the output current does not
exceed the current limit in
par. 4-18 Current Limit during ramping.
The value 0.00 corresponds to 0.01 sec.
in speed mode. See ramp-down time in
par. 3-62 Ramp 3 Ramp down Time.
Function:
Enter the ramp-down time, i.e. the decelera-
tion time from the rated motor speed n
RPM. Choose a ramp-down time such that no
over-voltage 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
par. 4-18 Current Limit. The value 0.00
corresponds to 0.01 s in speed mode. See
ramp-up time in par. 3-61 Ramp 3 Ramp up
Time.
t dec s x n s RPM
Par
. 3 − 62 =
ref RPM
Function:
Enter the proportion of the total ramp-up
time (par. 3-61 Ramp 3 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 in the
application.
MG.33.M9.02 - VLT
FC 300 Programming Guide
3-66 Ramp 3 S-ramp Ratio at Accel. End
Range:
50 % [Application
*
dependant]
3-67 Ramp 3 S-ramp Ratio at Decel. Start
Range:
50 % [Application
*
dependant]
3-68 Ramp 3 S-ramp Ratio at Decel. End
Range:
50 % [Application
*
dependant]
to 0
s
3.5.6 3-7* Ramp 4
Configure ramp parameters, see 3-4*.
3-70 Ramp 4 Type
Option:
[0] Linear
*
[1] S-ramp
Const Jerk
[2] S-ramp
Const Time
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is a registered Danfoss trademark
Function:
Enter the proportion of the total ramp-up
time (par. 3-61 Ramp 3 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 (par. 3-62 Ramp 3 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-
downdecel time (par. 3-62 Ramp 3 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.
Function:
Select the ramp type, depending on require-
ments for acceleration and deceleration. A
linear ramp will give constant acceleration
during ramping. An S-ramp will give non-linear
acceleration, compensating for jerk in the
application
Accelerates with lowest possible jerk.
S-ramp based on the values set in
par. 3-71 Ramp 4 Ramp up Time and
par. 3-72 Ramp 4 Ramp Down Time.