Baumuller b maXX BM5800 - Page 488

Controllers
Parameter manual b maXX BM5800
Document No.: 5.16029.03 Baumüller Nürnberg GmbH
488
of 814
3.7
Thereby, the inductance Lq accords to the inductance selected for the motor control: In-
ductance of measuring values (Z123.7–) or of motor data (Z107.34– and Z107.30– +
Z107.32–) according to the setting of bit 3 in Z123.10–.
The Ud voltage should not be more than the phase voltage U
ph,Max
. However, it is rec-
ommended to limit the voltage to the 1/2-fold U
ph,Max
.
Thereby the 100% PWM control and the present DC link voltage are considered to calcu-
late U
ph,Max
. This is the reason that at instantaneous reductions of the DC link voltage the
voltage limit and the torque current limit drops.
A limit speed n
E
, is implemented, as display parameter, from which the speed-dependent
torque current limit stronger than the set max. torque current
Z19.8– I
q,Max
the torque
current limits.
The resulting voltage phasor has by I
q,set
= l
q,Max
and n
act
= n
E
an angle of 45° (assuming
the Usq voltage of the field weakening is reduced to (1/
2) * U
ph,Max
). If this angle is
reached by the increase of the lq current there is no increase of the torque at the asyn
-
chronous machine anymore and therefore must be limited.
Factor of breakdown torque
Additionally, the operating speed still can be adjusted by the parameter Z138.17– (factor
at the breakdown torque S
k
). The smaller the factor the smaller the Ud voltage limit and
the greater the distance to the breakdown torque.
At the ASM S
k
may not be greater than 1. At the SM S
k
may be set >1 (but 2). This
way more torque current can be applied but the distance to the breakdown torque is re
-
duced.
The resulting speed-dependent torque current limit of the entered breakdown torque fac-
tor is displayed in parameter Z138.18– "Isq limit breakdown torque". The resulting limit
speed is displayed in "Breakdown torque limit" (Z138.16–).
The available phase voltage
The existent voltage, U
ph,Max
dependent of the field weakening controller mode is deter-
mined as follows:
m Field weakening at the voltage limit
U
d,Max
1
2
-------
U
ph,Max
=
n
E
60
el
2 p
--------------
60 U
d,Max

2 pL
q
I
qMax
 
--------------------------------------------==
U
d.Max
S
k
1
2
-------
U
ph,Max
=
U
ph,Max
1
3
-------
min u
max,
u
lim
=