Danfoss FC 300 Programming Manual page 57

Parameter Descriptions
3.5.4 3-5* Ramp 2
Choosing ramp parameters, see 3-4*.
3-50 Ramp 2 Type
Option: Function:
Select the ramp type, depending on require-
ments for acceleration/deceleration. A linear
ramp will give constant acceleration during
ramping. An S-ramp will give non-linear
acceleration, compensating for jerk in the
application.
[0] Linear
*
[1] S-ramp Acceleration with lowest possible jerk
Const Jerk
[2] S-ramp S-ramp based on the values set in
Const Time par. 3-51 Ramp 2 Ramp up Time and
par. 3-52 Ramp 2 Ramp down Time
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.
3-51 Ramp 2 Ramp up Time
Range: Function:
Applica- Enter the ramp-up time, i.e. the acceleration
tion [Applica- time from 0 RPM to the rated motor speed n
depend- tion Choose a ramp-up time such that the output
ent depend-
* current does not exceed the current limit in
ant]
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. 3-52 Ramp 2 Ramp down Time.
Par
. 3 − 51 =
3-52 Ramp 2 Ramp down Time
Range: Function:
Applica- Enter the ramp-down time, i.e. the decelera-
tion [Applica- tion time from the rated motor speed n
depend- tion RPM. Choose a ramp-down time such that no
ent depend- over-voltage arises in the inverter due to
*
ant] 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. 3-51 Ramp 2 Ramp up
Time.
Par
. 3 − 52 =
FC 300 Programming Guide
50 %
50 %
50 %
.
s
50 %
t acc s x n s RPM
ref RPM
3.5.5 3-6* Ramp 3
Configure ramp parameters, see 3-4*.
to 0
s
[0]
t dec s x n s RPM
[1]
ref RPM
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3-55 Ramp 2 S-ramp Ratio at Accel. Start
Range: Function:
[Application Enter the proportion of the total ramp-up
*
dependant] time (par. 3-51 Ramp 2 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.
3-56 Ramp 2 S-ramp Ratio at Accel. End
Range: Function:
[Application Enter the proportion of the total ramp-up
*
dependant] time (par. 3-51 Ramp 2 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.
3-57 Ramp 2 S-ramp Ratio at Decel. Start
Range: Function:
[Application Enter the proportion of the total ramp-
*
dependant] down time (par. 3-52 Ramp 2 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.
3-58 Ramp 2 S-ramp Ratio at Decel. End
Range: Function:
[Application Enter the proportion of the total ramp-
*
dependant] down time (par. 3-52 Ramp 2 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.
3-60 Ramp 3 Type
Option: 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.
Linear
*
S-ramp Accelerates with lowest possible jerk.
Const Jerk
3 3
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