Controllers
Parameter manual b maXX BM3000
Document no.: 5.12001.07 Baumüller Nürnberg GmbH
500
of 820
4.7
The output voltage effective U
max
is calculated by the complete PWM control and the
present DC link voltage.
Activation
The breakdown torque can be activated by Z138.1– bit 2. If the breakdown torque limit
is not activated then l
sq k limit
Z138.18– = l
sq Max
Z19.8–.
Breakdown torque adaption
To compensate moderate discrepancies in the motor parameters or compensate negligi-
ble effects to calculate the Ud voltage limit U
d,Max
an easy controlled adaption with a par-
allel comparison model (MRAS, Model Reference Adaptive System) can be activated
(
Z138.1– bit 5 to 1). Due to compatibility causes in general the adaption is not active. It
is recommended to activate the adaption at the activated breakdown torque, as well. The
operating principle of the adaption is presented in
ZFig. 166–.
Figure 166: Examples in regard to constant speed and moderate discrepancies in the motor parameters:
a) Too low without adaption and breakdown limit: Voltage limit Value is lower than calculated;
b) Including adaption although there are discrepancies, Value of the voltage limit as calculated: Breakdown limit okay.;
c) Without adaption and breakdown limit is too high: Value of the voltage limit is higher than calculated.
Difficulties and proceedings
If the values of speed, output frequency, torque current, motor inductances are high and
if the motor apparent voltage has reached its limit it should be checked if the d-,q-currents
still are properly controlled. If this is not the case it could be that the voltage of the con
-
troller is too low.
The voltage is determined by two variables at the motor. On the one side is the speed by
the EMC voltage (in the q-component of the motor voltage), on the other side the torque
by the torque current and the available impedance L
q
*
e
(L
*
e
at the ASM) in the d-com-
ponent of the motor voltage.
1 If the value of the Usd voltage Z47.21– is below the (1/2)-fold of the available phase
voltage U
ph,Max
it should be checked if the field weakening controller applies the re-
quired field weakening current (and at the ASM - if the magnetic flux weakening is suf-
ficient). If the latter is not the case it could be that the field weakening controller does
not apply the field weakening current quickly enough. However, the field weakening
controller can be adjusted more dynamically or support the controller by the field weak
-
ening characteristic. Another cause of an insufficient field weakening is that the SM
reached its limit (field current specification at the SM
Z19.9–). In general, the field cur-
5000_0365_rev01
0
0
a)
t
V
138.18
0
0
t
V
138.18
A
0
0
t
V
138.18
d,Max
U
b) c)
AA
sq,K,limit
i
sq,K,limit
i
sq,K,limit
i
isq-act 47.3 isq-act 47.3isq-act 47.3
usd-set 47.21 usd-set 47.21usd-set 47.21
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