Baumuller b maXX BM5800 - Page 721

Description of the Software Modules and Parameters
Parameter manual b maXX BM5800
Document No.: 5.16029.03
721
of 814
3
Figure 190: Continuous current limit characteristic by current supporting points and interpolation (see ZFig.
187– on page 718)
Continuous current limit characteristic by approximation of the iron losses
This option serves as an alternative by the current supporting points and interpolation
method if the information of the maximum continuous current as function of the speed is
not available. It can be activated by speed-dependent modes
Z6.43– bits 0 to 2, value =
2 and contains the approximation of the iron losses in dependence of the speed to calcu-
late the l
2
value. Thereby the iron losses are calculated using the standstill current
(
Z107.10–), the nominal current (Z107.9–), the nominal speed (Z107.7–) and the
smoothed effective speed (Z18.22–) and are added to the effective l
2
value. The stand-
still current is used as a reference for the continuous current, as well (the iron losses are
assumed zero at standstill). In case one of these values is not available (value equals ze
-
ro) the option cannot be activated. This option is specific to the motor standstill current >
motor rated current only. Between standstill and rated speed this method applies to the
continuous current characteristic quite accurate (within motor manufacturing tolerances);
from speeds greater than the rated speed the accuracy decreases steadily with increas
-
ing speed but in a conservative manner (a rather small continuous current is permitted
than permitted depending on the motor data).
Figure 191: Continuous current limit characteristic by approximation of the iron losses (see ZFig. 187– on
page 718)
N
D
N
D
107.72[0] ... 107.72[10]
n
18.22
5000_0359_rev01.cdr
Ref
I
Continuous current limit curve
I
act
'
Speed act. value
I value
2
N
D
N
D
N
D
N
D
N
N
o
I
2
o
I
N
I

22
Ref
I
o
I
107.10
107.7
18.22
107.9
N
I
if
o
I
N
I
,
if
o
I
N
I

,0
{
N
I
,
max()
o
I

5000_0360_rev01.cdr
Standstill current
Nominal speed
Speed actual value
Nominal current
I value
2
I
act