Danfoss VLT AutomationDrive FC 301 Programming Manual page 147

VLT AutomationDrive FC 301/302
Programming Guide
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
[0]* Linear
[1] S-ramp Const Jerk
[2] S-ramp Const Time
Parameter 3-61 Ramp 3 Ramp Up Time
Table 237: Parameter 3-61 Ramp 3 Ramp Up Time
3-61 Ramp 3 Ramp Up Time
Default value: Size related
Conversion index: -2
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.
t s × n RPM
acc s
Par . 3 − 61 =
ref RPM
Parameter 3-62 Ramp 3 Ramp Down Time
Table 238: Parameter 3-62 Ramp 3 Ramp Down Time
3-62 Ramp 3 Ramp Down Time
Default value: Size related
Conversion index: -2
Enter the ramp-down time, that is the deceleration time from the nominal motor speed n
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.
t s × n RPM
dec s
Par . 3 − 62 =
ref RPM
Parameter 3-65 Ramp 3 S-ramp Ratio at Accel. Start
Table 239: Parameter 3-65 Ramp 3 S-ramp Ratio at Accel. Start
3-65 Ramp 3 S-ramp Ratio at Accel. Start
Default value: 50%
Conversion index: 0
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.
Danfoss A/S © 2022.12
N O T I C E
Description
Acceleration with lowest possible jerk.
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 type: Range, 0.01 - 3600 s
Data type: Uint32
Parameter type: Range, 0.01 - 3600 s
Data type: Uint32
Parameter type: Range, 1 - 99%
Data type: Uint8
Parameter Descriptions
Setup: All setups
Change during operation: True
Setup: All setups
Change during operation: True
to 0 RPM. Select a ramp-down time such
s
Setup: All setups
Change during operation: True
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