Torque Generation - ABB DCS 600 MultiDrive Manual

3.7 Torque Generation

Interface between SDCS-AMC-DC 2 board and
DC control board SDCS-CON-2
The major signals exchanged each 2 ms between CON-
2 and AMC-DC 2 are:
speed actual value from
SPEED_ACTUAL
CON-2
active torque reference to
TORQ_USED_REF
CON-2
In addition, the calculated torque limits are read from
the CON-2 each 8 ms:
TC_TORQMAX
TC_TORQMIN
The addition of the torque correction TQ_CORR
from an analogue input of CON-2 is done by the
CON-2 software.
Armature voltage Control
This controller enables operation in the field weaken-
ing range. It generates the field current reference. At low
speeds the field current is constant and armature volt-
age is roughly proportional to the speed. At higher
speeds (≥ base speed) the field current reference is
reduced so that the armature voltage doesn't exceed its
reference.
Field Current Control
Two field exciters can be operated simultaneously for
two different motors.
The first field exciter can be operated with fixed current
reference, in field weakening or with a reduced refer-
ence for field heating.
The second field exciter has a fixed current reference
(no field weakening possible). However, it may be
reduced for field heating purposes.
A field reversal control is available for the first field
exciter.
Optitorque is a special control method where the flux
is reduced at small torque reference. This is available for
drives with and without field reversal.
Armature Current Control
The armature current reference is calculated from torque
reference and flux. Then it is processed by a ramp,
limitation and speed dependent limitation.
The actual value of the armature current is the meas-
ured mean value between two firing pulses.
The armature voltage reference is generated by a PI
controller.
The firing angle is calculated from this voltage reference
depending on the actual line voltage and the conduc-
tion time (adaptation between continuous and discon-
tinuous state of the converter current).
A simplified scheme of the armature current control is
given in diagram fig. 3.8/3.
3ADW000072R0501_DCS600_System_description_e_e
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