Fig. 3-4 Dtc Torque Control - ABB ACS5000 User Manual

ABB
Main circuit breaker
Direct torque control
Torque
reference
or
Speed
reference
Actual speed
Fig. 3-4 DTC torque control
5k A UM
The main circuit breaker (MCB) is an important switching and protection
device of the drive system. Therefore it must only be controlled and
monitored by the drive.
For further information, see:
■ Important note on main circuit breaker
■ Main circuit breaker engineering guideline
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.
Torque-
reference-
controller
Speed
controller
Switching of the semiconductors in the INU 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 microseconds and initiates switching whenever required.
3BHS221906 ZAB E01 Rev. D
Chapter 3 - Control system
Torque-
Switching
flux-
logic
comparator
Switch
positions
Motor
Voltage
model
Current
M
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