ABB ACS2000 AFE 2MVA User Manual page 54

CHAPTER 3 – CONTROL SYSTEM
Direct torque control
—
References
The speed and torque of the motor is controlled by
—
DTC (Direct Torque Control). DTC provides accu-
3-5 Direct torque control
rate speed and torque control, and high dynamic
speed response.
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 refer-
ence controllers.
Depending on the outputs from the hysteresis con-
trollers, the switching logic directly determines the
optimum switch positions every 50 microseconds
and initiates switching whenever required.
Torque reference
or
Speed reference
Actual speed
—
3-5
Torque-
reference
controller
Speed
controller
Peripheral I/O devices
The peripheral input and output devices connected
to the AMC circuit board of the INU include:
• Local CDP control panel
• I/O interfaces for parallel signal transfer to exter-
nal devices
• Optional fieldbus adapters for serial data trans-
fer to a higher-level control system
• PC-based service tools comprising:
®
- DriveWare software tools
®
DriveWare includes software tools such as
the commissioning and maintenance tools
DriveWindow and DriveDebug, and
DriveOPC for data transfer between ABB
drives and Windows
- RCM tool (Option): Tool for Remote Condi-
tion Monitoring.
Torque
Switching
flux
logic
comparator
Switch
positions
Motor
Voltage
model
Current
54
®
-based applications.
M