ID
Index Name
Unit Description
342
6
CON_FM_SpeedTab
%
342
7
CON_FM_SpeedTab
%
343
CON_FM_ImagTab
Magnetizing current scaling vs. speed
343
0
CON_FM_ImagTab
%
343
1
CON_FM_ImagTab
%
343
2
CON_FM_ImagTab
%
343
3
CON_FM_ImagTab
%
343
4
CON_FM_ImagTab
%
343
5
CON_FM_ImagTab
%
343
6
CON_FM_ImagTab
%
343
7
CON_FM_ImagTab
%
343
8
CON_FM_ImagTab
%
343
9
CON_FM_ImagTab
%
343
10
CON_FM_ImagTab
%
343
11
CON_FM_ImagTab
%
343
12
CON_FM_ImagTab
%
343
13
CON_FM_ImagTab
%
343
14
CON_FM_ImagTab
%
343
15
CON_FM_ImagTab
%
344
0
CON_FM_VConTF
ms
Voltage control filter time constant
345
0
CON_FM_VConKp
A/V
Voltage control gain
346
0
CON_FM_VConTn
ms
Voltage control integration time constant
347
0
CON_FM_VRef
%
Voltage control reference (relative to maximum
voltage)
348
0
CON_FM_SlipCon
%
Slip control gain for field weakening
435
0
CON_FM_FWMode
Mode of field weakening / d-current calculation
(PSM)
436
0
CON_FM_FWSpeedScale %
Speed scaling for field weakening (table mode)
437
0
CON_FM_FWCurrScale
%
q-current scaling for field weakening (table mode)
438
0
CON_FM_
FWMaxBackEMF
V
Maximum back-EMF in field weakening mode
(DC link voltage)
Table 7.24: “Field-weakening” parameters (continue)
MOOG
ID No.: CB40859-001 Date: 11/2020
MSD Servo Drive - Device Help
145
7 Control
ID
Index Name
Unit Description
421
CON_FM_FWTabIdx
Table index for field weakening / reluctance
torque utilization
421
0
CON_FM_FWTabIdx
Speed index
421
1
CON_FM_FWTabIdx
Torque index
422
0
CON_FM_FWTabId
A
d-current table entry
423
0
CON_FM_FWTabIq
A
q-current table entry
Table 7.25: “Field weakening - Interior permanent magnet synchronous motor
(IPMSM)” parameters
7.6.4 Field-weakening of asynchronous motor voltage
controller
The voltage controller is superimposed onto the selected characteristic curve. When
the voltage controller is used, a part of the available voltage is used as a control
reserve. The more dynamic the operation, the more control reserve is required. In
this case it may be that the voltage for rated operation is not sufficient, and also that
the controller starts to oscillate.
The PI voltage controller can be optimized by adaptation of the gain P 345[0] -
CON_FM_VConKp, integral-action time P 346[0] - CON_FM_VConTn and filter time
constant for motor voltage feedback P 344[0] - CON_FM_VConTF. P 347[0] - CON_
FM_VRef sets the voltage reference, though the threshold needs to be reduced in
response to rising demands as this maintains a kind of voltage reserve for dynamic
control processes.
A certain voltage reserve is required for stable operation. This is specified using
P 347[0] - CON_FM_VRef (< 100%). The value should be set high (≤ 90%) where
there are high demands in terms of dynamic performance. When using a lower
dynamic performance instead, the maximum achievable torque can be optimized in
relation to the current by using higher values (> 90%).
