Danfoss VLT AutomationDrive FC 301 Programming Manual page 74

Parameter Descriptions
3-28 Master Offset Speed Ref
Range:
3 3
3.4.4 Ramps
3-4* Ramp 1
For each of the 4 ramps (parameter groups 3-4* Ramp 1,
3-5* Ramp 2, 3-6* Ramp 3, and 3-7* Ramp 4) configure the
ramp parameters:
•
Ramp type,
•
Ramping times (duration of acceleration and
deceleration), and
•
Level of jerk compensation for S-ramps.
Start by setting the linear ramping times corresponding to
Illustration 3.25 and Illustration 3.26.
High-limit
Reference
P 4-11
Low limit
Illustration 3.25 Linear Ramping Times
If S-ramps are selected, set the level of non-linear jerk
compensation required. Set jerk compensation by defining
the proportion of ramp-up and ramp-down times where
acceleration and deceleration are variable (that is,
increasing or decreasing). The S-ramp acceleration and
deceleration settings are defined as a percentage of the
actual ramp time.
Speed
Ramp (X) S-Ramp
Ratio at Accel.End
Linear
Ramp (X)
S-Ramp
Ratio at
Accel.End
Illustration 3.26 Linear Ramping Times
72
Function:
ensure compatibility with software versions
48.01 and 48.10, this parameter is only
active when parameter 3-02 Minimum
Reference is set to 0.
RPM
P 4-13
n
s
P 3-*1 P 3-*2
Ramp (X)Up Ramp (X) Down
Time (Acc) Time (Dec)
t
acc
Ramp (X) S-Ramp
Ratio at Dec.End
Jerk compensated
Ramp (X)
Ramp (X)
Up Time
Down Time
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VLT AutomationDrive FC 301/302
3-40 Ramp 1 Type
Option:
[0] Linear
*
[1] S-ramp
Const
Jerk
[2] S-ramp
Const
Time
3-41 Ramp 1 Ramp up Time
Range:
3.00
Time
s
*
t
dec
3-42 Ramp 1 Ramp Down Time
Range:
3.00
s
*
Ramp (X)
S-Ramp
Ratio at
Dec.End
Function:
NOTICE
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.
Extra adjustment of the S-ramp ratios or
switching initiators 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.
Acceleration with lowest possible jerk.
S-ramp based on the values set in
parameter 3-41 Ramp 1 Ramp up Time and
parameter 3-42 Ramp 1 Ramp Down Time.
Function:
[0.01 - Enter the ramp-up time, that is the
3600.00 s] acceleration time from 0 RPM to the
synchronous motor speed n
up time which prevents the output current
from exceeding 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 3-42 Ramp 1 Ramp Down Time.
t s x n RPM
acc s
Par . 3 − 41 =
ref RPM
Function:
[0.01 - Enter the ramp-down time, that is the
3600.00 s] deceleration time from the synchronous
motor speed n to 0 RPM. Select a ramp-
s
down time such that no overvoltage occurs
in the inverter 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 3-41 Ramp 1
Ramp up Time.
t s x n RPM
dec s
Par . 3 − 42 =
ref RPM
. Select a ramp-
S
MG33MO02