Baumuller b maXX BM5800, Руководство по параметрам

Страница: 499 / 816

Description of the Software Modules and Parameters
Parameter manual b maXX BM5800
Document No.: 5.16029.03
499
of 814
3
3.7.7 Controller adaptations
Several adaptations and compensations are available to the controller. Some can be set
in the parameter (controller adaptations-) mode
Z
155.1
–
. The status of the controller ad-
aptations are shown in the parameter (controller adaptations-) status
Z
155.2
–
.
In general the controller can operate without adaption (compensation) from the deviating
operating conditions relative to nominal operation or from values deviating from the data
sheet. An adaption makes the manual setting of the controller parameters easier and
more reliable. On the other hand the adaption can improve the accuracy of some second-
ary variable display parameters (such as the motor voltage) and the encoderless model-
based processes.
Linear functions are preferred.
Refer to the following listing of factors that effect the controller.
Field weakening effects
At asynchronous motors in the field weakening the "system gain" Ks and the electro-mo-
toric force (EMF) of the motor drop when the magnetic flux falls (in contrast to the nominal
point).
Temperature effects
If the motor temperature rises the electric resistance value in the motor increases.
At synchronous machines with permanent magnets an increase of the motor temperature
causes a reversible weakening of the magnetic force. This produces a reversible drop of
the Kt-, Ke- and the Ks factors with the increasing motor temperature.
Saturation effects
In order to profit of the asynchronous motor normally the main inductance is brought to
the saturation point at the nominal point. In the field weakening with falling field current
the main inductance departs from the saturation. Due to this the value of the main induc-
tance increases and therewith the ratio of magnetic flux and the magnetizing current.
Generally, synchronous motors operate until standstill current lo in the linear range of the
torque current characteristic (or in the linear range of the Lq inductance, which means that
Lq is constant). In case of heavily loaded motors the Lq inductance is led to the saturation
limit. The torque per torque current and the Lq inductance drop similarly.
Load changing effects
If the load inertia changes considerably, then the actual "system gain" will strongly differ
from the used system gain (Ks factor
Z
18.40
–
) in the controller. At some applications the
changes can be preassigned. The controller can be adjusted during operation.
Fabrication tolerances
The motor data can differ in contrast to the data sheet with regard to the fabrication. For
instance the Kt factor of the synchronous motor can differ about ±8% (contact the motor
manufacturer concerning this matter).