Baumuller b maXX BM5800, Parameter Manual

Page: 82 / 816

Configuration
Parameter manual b maXX BM5800
Document No.: 5.16029.03 Baumüller Nürnberg GmbH
82
of 814
3.4
Additionally, in the field weakening range the torque is limited by the maximum power.
Therefore, the maximum available torque
Z
138.20
–
is constant in the base speed range.
In the field weakening range it decreases inversely proportional to the speed (see
Z
Fig.
33
–
on page 82).
Symmetric torque limit
The symmetric torque limit M
limit
(
Z
138.22
–
) influences the set value of the torque current
controller, which controls the torque-generating current. The correspondent limit for the
torque-generating current I
sq limit M
will be fit as follows.
with
Flux
setl
Magnetic flux set value in %
Z
146.13
–
Kt
upd
Kt updated
Z
155.24
–
, in Nm/A
Torque limits / torque current limits
Figure 33: a) Asynchronous motor: Torque limit above
Z
138.22
– 
b) Asynchronous motor: Overlap of several limits
If there are several torque limits
Z
138.22
–
, that result from the torque current limits
Z
138.2
–
,
Z
138.3
–
,
Z
138.14
–
,
Z
138.15
–
or from the breakdown torque-current limit op-
erating simultaneously then the smallest limit is decisive (compare
Z
Fig. 33
–
(b)). Note:
In
Z
Fig. 33
–
(b) the "Current mode" is assumed (
Z
138.1
–
bit 3 = 1) with regard to the
parameters
Z
138.2
–
,
Z
138.3
–
,
Z
138.14
–
,
Z
138.15
–
.
Particular case synchronous motor with interior permanent magnet (IPMSM)
The torque is calculated from the characteristic map of the IPMSM and from the currents
according to the following formula:
I
sq limit M
M
limit
Kt
upd
Flux
set
[%]

-------------------------------------------- =
n [min ]
N
107.7
N
-1
N
max mech
107.26
max
M
m
[Nm]
(138.20)
M
n [min ]
N
107.7
N
-1
N
max mech
107.26
max
M
m
[Nm]
(138.20) M
a) b)
5000_0235_rev02_int
Lim
= (Iq ) = f
Lim
(138.22)
Lim
min (138.2,138.3,138.14,138.15)
Lim
(138.22) M
| | | |
f (138.18)
base speed
range
field weakening
base speed
range
field weakening
effective
limits
=
M
Lim bd