Speed Control Mode; Torque Control Mode; Frequency Control Mode; Dc Voltage Control Mode - ABB ACS880 Firmware Manual

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Speed control mode

The motor follows a speed reference given to the drive. This mode can be used either
with estimated speed as feedback, or with an encoder or resolver for better speed
control accuracy.
Speed control mode is available in both local and external control. It is also available
both in DTC (Direct Torque Control) and scalar motor control modes.
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Torque control mode

Motor torque follows a torque reference given to the drive. Torque control is possible
without feedback, but is much more dynamic and accurate when used in conjunction
with a feedback device such as an encoder or a resolver. It is recommended that a
feedback device is used in crane, winch or lift control situations.
Torque control mode is available in DTC motor control mode for both local and
external control locations.
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Frequency control mode

The motor follows a frequency reference given to the drive. Frequency control is only
available in scalar motor control mode.
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DC voltage control mode

This mode is intended especially for off-grid applications where the inverter unit is
connected to a generator and the supply unit creates an AC supply network.
The inverter unit adjusts the DC voltage by controlling generator torque. Based on the
DC circuit capacitance either from an internal database or user input parameter, and
measured DC voltage, the PI controller outputs a power reference. The power
reference is then converted to a torque reference.
The settings of the DC voltage control chain are available in parameter group
Voltage reference chain.
DC voltage control mode is only available with drives with a BCU control unit.
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Special control modes

In addition to the control modes mentioned above, the following special control
modes are available:
• Process PID control. For more information, see section
66).
• Emergency stop modes Off1 and Off3: Drive stops along the defined deceleration
ramp and drive modulation stops.
• Jogging mode: Drive starts and accelerates to the defined speed when the
jogging signal is activated. For more information, see section
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Control locations and operating modes 23
Process PID control
29
(page
Jogging (page 55).