l
Be calculated internally by the firmware (small table), OR
l
Be specified externally, for example using a higher-order control (large
table), OR
l
Be loaded via the file system (large table)
Two LUTs of different sizes (small and large table) are implemented for this purpose.
Each of these tables has two performance maps, one for the direct axis ref. currente
and one for the q-current reference values. Each are dependent on the actual speed
‘nact’ (x-direction) and the target torque ‘Tset’ (y-direction): field[x*y].
Small table
The small table has a fixed size for the performance map of
[16x40]
table entries. It is
calculated
internally
by the servo drive. Only positive torques.
Activate small LUT: P 435[0] - CON_FM_FWMode =
REL(3)
The inductances of the d and q axis must be known in order to calculate the LUT
values internally.
ID
Index Name / Setting
Unit Function
P 471
0
MOT_Lsig
mH
d axis inductance
P 480
0
MOT_Lsq
mH
q axis inductance
Table 7.29: Specifying the inductances of the d and q axis
The values for the two inductances must be taken from the motor data sheet or can
be determined by means of the motor identification (
MOOG
ID No.: CB40859-001 Date: 11/2020
MSD Servo Drive - Device Help
151
7 Control
Large table
The large table has a variable size for the performance map which can be set for a
minimum of
[3x3] to a maximum of [128x128]
table entries. It is
specified externally
to the servo drive Negative torques are also possible.
Activate large LUT: P 435[0] - CON_FM_FWMode =
LUText(6)
The size of the map in the large table can be adapted using parameter P 1965 -
CON_FM_LUT_Para[0,1].
ID
Index Name / Setting
Unit Function
P 1965
CON_FM_LUT_Para
P 1965
0
LUT: Useof speed
Table size in the speed direction
Factory setting: 121
Minimum: 3
Maximum: 128
P 1965
1
LUT: Useof torque
Table size in the torque direction
Factory setting: 31
Minimum: 3
Maximum: 128
Table 7.30: Specifying the size of the performance map for the large table
The scaling of the map for the d and q current reference results from the nominal
torque TNom and the nominal speed SNom as well as the associated scaling
parameters TMax and SMax.
