Optimising The Stalling Behaviour - Lenze 8400 StateLine C Reference Manual

5.7.4.4

Optimising the stalling behaviour

Motor stalling due to a torque overload in the field weakening range in sensorless vector
control is prevented by means of an inverter-internal stalling current monitoring. In the
field weakening range, hence at frequencies above the base frequency, it reduces the
maximum current to prevent the motor from stalling. The reduction depends on the
current field frequency, the base frequency, the DC-bus voltage and the maximum current
(C00022). Generally it applies that a higher field frequency causes a stronger limitation of
the maximum current.
The field weakening behaviour of the sensorless vector control depends on the setting of
the reset time Ti of the torque controller (C00074/2).
The following applies to the reset time Ti (C00074/2) > 15 ms:
The behaviour in the field weakening range can be adapted via the override point of field
weakening (C00080). This parameter serves to shift the frequency-dependent maximum
current characteristic:
C00080

– The maximum current characteristic is shifted by the entered frequency to higher
field frequencies.
– The maximally permissible current and the maximum torque increase in the field
weakening range.
– The risk of motor stalling increases.
C00080

– The maximum current characteristic is shifted by the entered frequency to lower
field frequencies.
– The maximally permissible current and the maximum torque are reduced in the field
weakening range.
– The risk of motor stalling is reduced.

Note!
We recommend to keep the Lenze setting (0 Hz).
Firmware ≤ 11.00 - DMS 8.0 EN - 10/2011
Phone: 800.894.0412 - Fax: 888.723.4773 - Web: www.clrwtr.com - Email: info@clrwtr.com
> 0 Hz:
< 0 Hz:
L
8400 StateLine C | Reference manual
Sensorless vector control (SLVC)
Motor control (MCTRL)
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