Lenze 8400 motec Series, Software Manual, Page: 74 / 376

8400 motec | Software Manual
Motor control (MCTRL)
V/f characteristic control (VFCplus)
74
L
Firmware
≤
02.00 - DMS 2.1 EN - 03/2011
5.5.3.3 Optimising the Imax controller
Using the Lenze setting of the current limitation controller, the drive is stable:
Most applications do not require optimisation.
The setting of the current limitation controller must be adapted if

power control including great moments of inertia is performed.
– Recommendation: Increase of the reset time Ti (
C00074 ) of the I
max
controller.

vibrations occur in the V/f control (V encoder) mode during the intervention of
the current limitation controller.
– Recommendation: Increase of the reset time Ti (
C00074 ) of the I
max
controller.

overcurrent errors occur due to load impulses or too high acceleration ramps.
– Recommendation: Reduction of the gain Vp (
C00073 ) and reset time Ti ( C00074 ) of
the I
max
controller

Note!
V
min
boost is automatically calculated by the motor parameter identification
using the data specified on the motor nameplate so that a no-load current of
approx. 0.8 I
rated motor
results at the slip frequency of the machine.
V/f control (V encoder)
If V/f control (V encoder) is selected, we recommend a decidedly lower
V
min
boost:
• In this case, select a V
min
boost which ensures that approx. 50 % of the rated
motor current flows at slip frequency when the motor is idling.
Parameter Info Lenze setting
Value Unit
C00073 VFC: Vp Imax controller 0.25
C00074 VFC: Ti Imax controller 65 ms