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:
Function:
Application
dependent
*
[Application
dependant]
Enter the ramp-up time, i.e., the
acceleration time from 0 RPM to
the rated motor speed n
s
.
Choose a ramp-up time 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 sec. in speed
mode. See ramp-down time in
3-62 Ramp 3 Ramp down Time
.
3-62 Ramp 3 Ramp down Time
Range:
Function:
Application
dependent
*
[Application
dependant]
Enter the ramp-down time, i.e., the
deceleration time from the rated
motor speed n
s
to 0 RPM. Choose a
ramp-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
4-18 Current Limit
. The
value 0.00 corresponds to 0.01 sec. in
speed mode. See ramp-up time in
3-61 Ramp 3 Ramp up Time
.
Par. 3 − 62 =
tdec s x ns RPM
ref RPM
3-65 Ramp 3 S-ramp Ratio at Accel. Start
Range:
Function:
50 %
*
[Application
dependant]
Enter the proportion of the total
ramp-up time (
3-61 Ramp 3 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.
3-66 Ramp 3 S-ramp Ratio at Accel. End
Range:
Function:
50 %
*
[Application
dependant]
Enter the proportion of the total
ramp-up time (
3-61 Ramp 3 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.
3-67 Ramp 3 S-ramp Ratio at Decel. Start
Range:
Function:
50 %
*
[Application
dependant]
Enter the proportion of the total
ramp-down time (
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.
3-68 Ramp 3 S-ramp Ratio at Decel. End
Range:
Function:
50 %
*
[Application
dependant]
Enter the proportion of the total
ramp-downdecel time (
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.
3.5.6 3-7* Ramp 4
Configure ramp parameters, see 3-4*.
3-70 Ramp 4 Type
Option:
Function:
Select the ramp type, depending on
requirements 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.
[0]
*
Linear
[1]
S-ramp
Const Jerk
Accelerates with lowest possible jerk.
[2]
S-ramp
Const Time
S-ramp based on the values set in
3-71 Ramp
4 Ramp up Time
and
3-72 Ramp 4 Ramp Down
Time
.
Parameter Descriptions
FC 300 Programming Guide
3-40
MG33MD22 - VLT
®
is a registered Danfoss trademark
3
3
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