Baumuller b maXX BM5800 - Page 489

Description of the Software Modules and Parameters
Parameter manual b maXX BM5800
Document No.: 5.16029.03
489
of 814
3
u
max
, Maximum output voltage RMS, Z142.6–
u
lim
, Voltage threshold for field weakening, Z142.8–
m Permanent field weakening
u
max
, Maximum output voltage RMS, Z142.6–
The output voltage effective U
max
is calculated by the 100% 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 and if breakdown torque controller is not active then
l
sq k limit
138.18 = l
sq Max
Z19.8–.
Breakdown torque adaption
To compensate moderate discrepancies in the motor parameters or compensate negligi-
ble effects to calculate the breakdown torque limit an adaption with an easy parallel com-
parison model (MRAS, Model Reference Adaptive System) can be activated (Z138.1–
bit 5 to 1). Due to compatibility causes the adaption is not active as default. It is recom-
mended to activate the adaption at the activated breakdown torque, as well. The operat-
ing principle of the adaption is presented in ZFig. 130–.
Figure 130: 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 expected; 
b) Including adaption although there are discrepancies, Value of the voltage limit as expected: Breakdown limit okay.; 
c) Without adaption and breakdown limit is too high: Value of the voltage limit is higher than expected.
Problems and proceedings
If the values of speed, output frequency, torque current, motor inductances are high it
should be checked if the d-,q-currents still are properly controlled. If this is not the case it
could be that there is not enough voltage available for the controller.
With regard to the set voltage "PWM total voltage smoothed" Z142.7– the "Maximum to-
tal PWM voltage" Z142.6– can be controlled (by means of the oscilloscope function for
U
ph,Max
1
3
-------
u
max
=
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