862 HEIDENHAIN Technical Manual MANUALplus 620
6.16.12 Peculiarities in weakened-field operation with CC 61xx and CC 424
Reduction of the
magnetization
current
Some of the asynchronous spindle motors require a high magnetizing current
at low speeds (n < n
field weakening
). This magnetizing current can, however,
lead to thermal motor problems at the rpm for field weakening n
FW
when
there is no load.
The nominal voltage (and so also the nominal magnetization current) at the
rpm for field weakening n
FW
when there is no load can be reduced with
MP_iCtrlMotVRedFact. The entered reduction results in a nominal voltage
curve as shown in the figure below. The maximum nominal voltage is reached
when n=3·n
field weakening
. The nominal voltage can be reduced by max. 60
% (MP_iCtrlMotVRedFact =60).
If a load is placed on the drive, then the nominal voltage is increased again
automatically in order to improve the dynamics.
Settings in the configuration editor MP number
Axes
ParameterSets
[Key name of the parameter set]
CfgCurrentControl
iCtrlMotVRedFact 401005
n
3 · n
FW
n
FW
MP_iCtrlMotVRedFact
U
nominal