Lenze 8400 motec Series, Software Manual, Page: 92 / 376

8400 motec | Software Manual
Motor control (MCTRL)
V/f control (V encoder)
92
L
Firmware
≤
02.00 - DMS 2.1 EN - 03/2011
Controller limitation
The max. influence of the slip regulator is limited via the controller limitation ( C00971/1 ).

The controller can be limited depending on the application.

It is recommended to limit the maximum influence to double the rated slip of the
motor.

The rated slip is calculated as follows:
[5-4] Calculation of the rated slip
Slip limitation
In addition to limiting the slip regulator, the field frequency to be injected can also be
limited by another limiting element, the slip limitation ( C00971/2 ).

A slip limitation to, for instance, double the rated slip of the motor prevents the motor
from stalling in very dynamic processes.

Motor stalling is caused by:
– High overcurrent at very steep speed ramps
– very quick load-related speed variations, e.g. sudden stopping of the drive when
travelling against a limit stop or a standing load.
f
Slip
Rated
Hz [ ] f
Rated
Hz [ ]
n
Motor
Rated
rpm
[ ]
60
------------------------------------------ p
Number of pole pairs
⋅
⎝ ⎠
⎛ ⎞
– =

Note!
The setting C00971/1 = 0 Hz deactivates the slip regulator. In this case, the
structure of the V/f control corresponds to the structure of the V/f characteristic
control without feedback.