P No.
Index Name
Unit Description
344
0
CON_FM_VConTF
ms
Time constant of voltage controller actual value
filter
345
0
CON_FM_VConKp
A/V
Voltage controller gain factor Kp
346
0
CON_FM_VConTn
ms
Voltage controller integral-action time Tn
347
0
CON_FM_VRef
%
Voltage controller reference (as % of the current
DC link voltage) If the value 0 % is set, the
controller is not active.
458
0
MOT_SNom
rpm Motor rated speed
Table 7.26: “Voltage controller” parameters
NOTE
l
If the control reserve is too small, the Servo Drive typically shuts
off with an overcurrent error.
MOOG
ID No.: CB40859-001 Date: 11/2020
MSD Servo Drive - Device Help
146
7 Control
7.7 Field weakening and LookUpTable (LUT),
synchronous motor
LookUp Table, LUT
For better control of motors with a torque reluctance component. For motors with
different inductances on the d and q axis, a reluctance torque can contribute to
obtaining better utilization of the overall torque. The d and q current have feed
forward control in dependence on the target torque and the actual speed by means
of tables (LUT). As this approach also subjects the d component of the current to
feed forward control in exactly the same manner as the field weakening designed to
achieve higher speeds as described below, the LUT usually considers both the
torque and the field weakening simultaneously for the d current.
Field weakening
Synchronous motors can also be operated above their rated speed at rated voltage
by reducing their voltage consumption through the injection of a current component.
Features
l
The method is relatively robust against parameter fluctuations.
l
The voltage controller can only follow rapid speed and torque changes to a
limited degree.
l
A non-optimized voltage controller may cause oscillation; the controller must
be optimized.
