Ramp - Danfoss VLT AutomationDrive EZ FC 321 Programming Manual

VLT® AutomationDrive EZ FC 321
Programming Guide
Enter the proportion of the total ramp-down time (parameter 3-42 Ramp 1 Ramp Down Time) where the deceleration torque decrea-
ses. The larger the percentage value, the greater the jerk compensation achieved, and thus the lower the torque jerks in the applica-
tion.

4.4.4 3-5* Ramp 2

Parameter 3-50 Ramp 2 Type
Table 190: Parameter 3-50 Ramp 2 Type
3-50 Ramp 2 Type
Default value: [1] Linear
Conversion index: –
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 3-51 Ramp 2 Ramp Up Time
Table 191: Parameter 3-51 Ramp 2 Ramp Up Time
3-51 Ramp 2 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 3-52 Ramp 2 Ramp Down Time.
t s × n RPM
acc s
Par . 3 − 51 =
ref RPM
Parameter 3-52 Ramp 2 Ramp Down Time
Table 192: Parameter 3-52 Ramp 2 Ramp Down Time
3-52 Ramp 2 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 3-51 Ramp 2 Ramp Up Time.
114 | Danfoss A/S © 2021.08
Parameter type: Option
Data type: Uint8
N O T I C E
Description
Acceleration with lowest possible jerk.
S-ramp based on the values set in parameter 3-51 Ramp 2 Ramp Up Time and parameter 3-52 Ramp
2 Ramp Down Time.
Parameter type: Range, 0.01 - 3600 s
Data type: Uint32
Parameter type: Range, 0.01 - 3600 s
Data type: Uint32
Parameter Descriptions
Setup: All setups
Change during operation: True
Setup: All setups
Change during operation: True
Setup: All setups
Change during operation: True
to 0 RPM. Select a ramp-down time such
s
AU373327181955en-000101 / 130R1208