ABB ACS5000 User Manual page 50

Direct torque control
The speed and torque of the motor is controlled by DTC (Direct Torque
Control). The DTC motor control platform is unique to ABB and has been
proven in all variable speed drives of the ACS product range. DTC provides
accurate speed and torque control, and high dynamic speed response.
DTC is implemented on the AMC circuit board of the INU.
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(1) Torque reference
(2) Speed reference
(3) Actual reference
(4) Speed controller
(5) Torque reference controller
(6) Torque-flux comparator
Switching of the semiconductors i is directly controlled in accordance
with the motor core variables flux and torque.
The measured motor currents and DC link voltages are inputs to an
adaptive motor model. The model produces exact values of torque and
flux every 25 microseconds. Motor torque and flux comparators compare
the actual values to reference values which are produced by the torque
and flux reference controllers.
Depending on the outputs from the hysteresis controllers, the switching
logic directly determines the optimum switch positions every 50 ms and
initiates switching whenever required.
Parameters
The control system is configured, customized, and tuned with a set of
application parameters. The application parameters are organized in
functional groups and have factory-set default values.
The default parameter values are adjusted during commissioning to the
specific application of the drive in order to activate the specific control,
monitoring and protection functions for the driven process, and to define
the signals and data transferred between drive and external equipment.
3BHS799208 E01 REV E
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Figure 3-13 DTC torque control
ACS5000 WATER-COOLED USER MANUAL
03 POWER ELECTRONICS AND CABINET FEATURES
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(7) Motor model
(8) Switching logic
(9) Switch positions
(10) Voltage
(11) Current
(12) Motor
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