Baumuller b maXX BM5800, Руководство по параметрам

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Description of the Software Modules and Parameters
Parameter manual b maXX BM5800
Document No.: 5.16029.03
189
of 814
3
3.4.8 Autotuning of position / speed controller
The "system gain" that is determined by the complete inertia of the drive, the motor-torque
constant Kt and the magnetic flux are combined at the rated point in the Ks factor
Z
18.40
–
.
The actual value of the "gain" is calculated in the parameter ""Ks actual value"
Z
155.10
–
.
The inverse of the "Ks actual value"
Z
155.10
–
: (1/Ks
act
), serves in the controller as a
standardization constant between the acceleration value (speed controller output) and
the torque current set value. Therefore, ideally, the parameterization of the posi-
tion/speed controller is independent of the existing controlled system. The speed control-
ler can be parameterized with a symmetric optimum independent of the used motor and
the existing drive inertia.
The optimized values of the speed controller can not be used for all drives. For example,
a great load inertia could cause that the distortion in the torque current set value exceeds
10% of the motor nominal current. The excessive distortion is caused by the speed ripple
(dependent of the encoder type) and amplified by a (1/Ks
act
) which is too great. In this
case the encoder smoothing should be increased (to reduce the ripple) or a smoother set-
ting of the speed controller should be made. ProDrive offers a calculating tool for a
smoother setting.
Automatic identification of controlled system
It is possible to carry out an automatic identification of the controlled system with the con-
troller. The values at the speed controller, the positioning controller Kv factor as well as
at the inertia and the Ks factor are determined. See
Z
Control loop analysis
–
on page 198
for a detailed description.
3.4.8.1 Ks Determination
Refer to
Z
The factor Ks
–
on page 404 for a general description of the factor Ks.
The value of the factor Ks at the nominal point, Ks factor
Z
18.40
–
can be calculated or
measured.
Ks calculation
The Ks factor
Z
18.40
–
can be calculated as follows:
with
Ks factor Parameter
Z
18.40
–
in (degree/s
2
)/A
Flux
nom
100% (according to definition of the Ks factor
Z
18.40
–
)
Kt Kt = Kt factor, in Nm/A
Kt factor Motor Kt in Nm/A
Z
107.44
–
J Torque of the drive in kg m
2
(Attention: Torque inertia parameters of the

controller are shown in kg cm
2
!)
Ks factor
180
o

-----------
Flux
nom
[%]
Kt
J
------
 
=