58 Program features
Settings
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Scalar motor control
It is possible to select scalar control as the motor control method instead of DTC
(Direct Torque Control). In scalar control mode, the drive is controlled with a speed or
frequency reference. However, the outstanding performance of DTC is not achieved
in scalar control.
It is recommended to activate scalar motor control mode
• if the nominal current of the motor is less than 1/6 of the nominal output current of
the drive
• if the drive is used without a motor connected (for example, for test purposes)
• if the drive runs a medium-voltage motor through a step-up transformer, or
• in multimotor drives, if
•
the load is not equally shared between the motors,
•
the motors are of different sizes, or
•
the motors are going to be changed after motor identification (ID run)
In scalar control, some standard features are not available.
See also section
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IR compensation for scalar motor control
IR compensation (also known as voltage
boost) is available only when the motor
control mode is scalar. When IR
compensation is activated, the drive
gives an extra voltage boost to the motor
at low speeds. IR compensation is useful
in applications that require a high break-
away torque. In step-up applications,
voltage cannot be fed through the
transformer at 0 Hz, so an additional
breakpoint is available for defining the
compensation near zero frequency.
In Direct Torque Control (DTC), no IR compensation is possible or needed as it is
applied automatically.
Motor voltage
f
(Hz)
IR compensation
No compensation
Summary of Contents for ACS880-x04
Page 1: ... ABB INDUSTRIAL DRIVES ACS880 primary control program Firmware manual ...
Page 4: ......
Page 18: ...18 Using the control panel ...
Page 24: ...24 Control locations and operating modes ...
Page 112: ...112 Application macros ...
Page 496: ...496 Additional parameter data ...
Page 544: ...544 Fault tracing ...
Page 602: ...602 Control chain diagrams ...