In scalar control, some standard features are not available.
IR compensation for a scalar controlled drive IR stands for voltage.
I (current) × R (resistance) = U (voltage).
IR compensation is active 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 direct torque control (DTC) mode, IR
compensation is automatic and manual adjustment is not needed.
Sensors like absolute encoders and resolvers indicate the rotor position at all times
after the offset between the zero angle of rotor and that of the sensor has been
established. On the other hand, a standard pulse encoder determines the rotor
position when it rotates but the initial position is not known. However, a pulse
encoder can be used as an absolute encoder if it is equipped with Hall sensors,
albeit with coarse initial position accuracy. The Hall sensors generate so-called
commutation pulses that change their state six times during one revolution, so it is
only known within which 60° sector of a complete revolution the initial position is.
The drive monitors the motor status continuously, also during flux braking.
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