Danfoss FC 300 Design Manual page 155

FC 300 Design Guide
the jerk compensation achieved, and thus the
lower the torque jerks in the application.
3-5* Ramp 2
Choosing ramp parameters, see 3-4*.
3-50 Ramp 2 Type
Value:
Linear
S-ramp
Function:
Select the ramp type, depending on requirements
for acceleration/deceleration. A linear ramp will
give constant acceleration during ramping. An S-
ramp will give non-linear acceleration, compen-
sating for jerk in the application.
NB!
If S-ramp [1] is selected and the ref-
erence 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
way.
Additional adjustment of the S-ramp
ratios or switching initiators may be
necessary.
3-51 Ramp 2 Ramp up Time
Value:
0.01 - 3600.00 s
Function:
Enter the ramp-up time, i.e. the acceleration time
from 0 RPM to the rated motor speed n
1-25). Choose a ramp-up time such that the out-
put current does not exceed the current limit in
par. 4-18 during ramping. The value 0.00 corre-
sponds to 0.01 sec. in speed mode. See ramp-
down time in par. 3-52.
t x
acc
Par
. 3 − 51 =
3-52 Ramp 2 Ramp down Time
Value:
0.01 - 3600.00 s.
factory setting
How to Programme
[0]
[1]
(par.
M,N
par
η . 1 − 25
norm
sec
ref RPM
∆
() display text []
MG.33.B7.02 - VLT is a registered Danfoss trademark
Function:
Enter the ramp-down time, i.e. the deceleration
time from the rated motor speed n
to 0 RPM. Choose a ramp-down time such that no
over-voltage arises in the inverter due to regen-
erative operation of the motor, and such that the
generated current does not exceed the current
limit set in par. 4-18. The value 0.00 corresponds
to 0.01 s in speed mode. See ramp-up time in par.
3-51.
t
Par
. 3 − 52 =
Ramp 2 S-ramp Ratio at Accel.
3-55
Start
Value:
1 - 99%
Function:
Enter the proportion of the total ramp-up time
(par. 3-51) in which the acceleration torque in-
creases. The larger the percentage value, the
greater the jerk compensation achieved, and thus
the lower the torque jerks in the application.
3-56 Ramp 2 S-ramp Ratio at Accel. End
Value:
1 - 99%
Function:
Enter the proportion of the total ramp-up time
s (par. 3-51) in which the acceleration torque de-
creases. The larger the percentage value, the
greater the jerk compensation achieved, and thus
the lower the torque jerks in the application.
Ramp 2 S-ramp Ratio at Decel.
3-57
Start
Value:
1 - 99%
Function:
Enter the proportion of the total ramp-down time
(par. 3-52) where the deceleration torque increa-
ses The larger the percentage value, the greater
the jerk compensation achieved, and thus the
lower the torque jerks in the application.
s
value for use in communication via serial communication port
(par. 1-25)
M,N
x par
η . 1 − 25
dec norm
ref RPM
∆
sec
50%
50%
50%
155