N O T I C E
If
[1] S-ramp Const Jerk
is selected and the reference during ramping is changed, the ramp time may be prolonged 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 ini-
tiators may be necessary.
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.
Option Name
Description
[0]*
Linear
[1]
S-ramp Const Jerk
Acceleration with lowest possible jerk.
[2]
S-ramp Const Time S-ramp based on the values set in
parameter 3-61 Ramp 3 Ramp Up Time
and
parameter 3-62 Ramp
3 Ramp Down Time
.
Parameter 3-61 Ramp 3 Ramp Up Time
Table 198: Parameter 3-61 Ramp 3 Ramp Up Time
3-61 Ramp 3 Ramp Up Time
Default value: Size related
Parameter type: Range, 0.01 - 3600 s
Setup: All setups
Conversion index: -2
Data type: Uint32
Change during operation: True
Enter the ramp-up time, that is the acceleration time from 0 RPM to the nominal motor speed ns. Select a ramp-up time such that
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 3-62 Ramp 3 Ramp Down Time
.
Par . 3 − 61 =
t
acc
s
×
n
s
RPM
ref RPM
Parameter 3-62 Ramp 3 Ramp Down Time
Table 199: Parameter 3-62 Ramp 3 Ramp Down Time
3-62 Ramp 3 Ramp Down Time
Default value: Size related
Parameter type: Range, 0.01 - 3600 s
Setup: All setups
Conversion index: -2
Data type: Uint32
Change during operation: True
Enter the ramp-down time, that is the deceleration time from the nominal motor speed n
s
to 0 RPM. Select a ramp-down time such
that no overvoltage occurs in the drive 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 3-61 Ramp 3 Ramp Up Time
.
Par . 3 − 62 =
t
dec
s
×
n
s
RPM
ref RPM
Parameter 3-65 Ramp 3 S-ramp Ratio at Accel. Start
Table 200: Parameter 3-65 Ramp 3 S-ramp Ratio at Accel. Start
3-65 Ramp 3 S-ramp Ratio at Accel. Start
Default value: 50%
Parameter type: Range, 1 - 99%
Setup: All setups
Conversion index: 0
Data type: Uint8
Change during operation: True
Enter the proportion of the total ramp-up time (
parameter 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 occurring in the
application.
AU373327181955en-000101 / 130R1208
116 | Danfoss A/S © 2021.08
Parameter Descriptions
VLT® AutomationDrive EZ FC 321
Programming Guide
