Scalar Control; Settings; Ir Compensation For A Scalar Controlled Drive; Programmable Protection Functions - ABB ACS355 User Manual

144 Program features

Scalar control

It is possible to select scalar control as the motor control method instead of vector
control. In the scalar control mode, the drive is controlled with a frequency reference.
It is recommended to activate the scalar control mode in the following special
applications:
• In multimotor drives: 1) if the load is not equally shared between the motors,
2) if the motors are of different sizes, or 3) if the motors are going to be changed
after the motor identification.
• If the nominal current of the motor is less than 20% of the nominal output current
of the drive.
• When the drive is used for test purposes with no motor connected.
The scalar control mode is not recommended for permanent magnet motors.
In the scalar control mode, some standard features are not available.

Settings

Parameter 9904 MOTOR CTRL MODE

IR compensation for a scalar controlled drive

IR compensation is active only when the motor
control mode is scalar (see section
control on page 144). 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 high break-
away torque. In vector control, no IR
compensation is possible/needed.
Settings
Parameter 2603 IR COMP VOLT

Programmable protection functions

AI<Min
AI<Min function defines the drive operation if an analog input signal falls below the
set minimum limit.
Settings
Parameters 3001 AI<MIN
LIMIT
Scalar
FUNCTION, 3021 AI1 FAULT LIMIT
Motor voltage
IR compensation
No compensation
and 3022 AI2 FAULT
f (Hz)