BONFIGLIOLI ACTIVE Cube ACU 201-01, Operating Instructions Manual, Page: 226 / 292

17.4 Functions of Sensorless Control
The configurations of the sensorless control contain the following additional func-
tions, which supplement the behavior according to the parameterized V/f characteris-
tic.
17.4.1 Slip compensation
The load-dependent difference between the reference speed and the actual speed of
the 3-phase motor is referred to as the slip. This dependency can be compensated by
the current measurement in the output phases of the frequency inverter.
The activation of
Operation mode
660 for the slip compensation enables as speed
control without feedback. The stator frequency and speed are corrected depending
on the load.
The slip compensation is activated during the guided commissioning. The
Stator Re-
sistance
377 is required to ensure a correct function and is measured during the
guided commissioning.
If no guided commissioning is executed, the slip compensation can be activated
manually. In these cases, enter the value for the
Stator Resistance
377 manually
according to the motor data sheet.
Operation mode
660 Function
0 - Off The slip compensation is deactivated.
1 - On The load-dependent slip speed is compensated.
The control behavior of the slip compensation can only be optimized via the parame-
ters in the case of specific applications. The parameter
Amplification
661 determines
the correction of the speed and the effect of the slip compensation proportionally to
the change of load. The
Max. Slip ramp
662 defines the max. frequency change per
second in order to avoid an overload in the case of a load change.
The parameter
Minimum frequency
663 determines the frequency as from which the
slip compensation becomes active.
Parameter Settings
No. Description Min. Max. Fact. sett.
661 Amplification 0.0 % 300.0 % 100.0 %
662 Max. Slip Ramp 0.01 Hz/s 650.00 Hz/s 5.00 Hz/s
663 Minimum Frequency 0.01 Hz 999.99 Hz 0.01 Hz
17.4.2 Current limit value controller
Via a load-dependent speed control, the current limit value controller ensures that
the drive system is not overloaded. This is extended by the intelligent current limits
described in the previous chapter. The current limit value controller reduces the load
on the drive, e.g. during acceleration, by stopping the acceleration ramp. The switch-
off of the frequency inverter which happens when the acceleration ramps have been
set at an excessive gradient is prevented in this way.
The current limit value controller is switched on and off via parameter
Operation
mode
610.
Operation mode
610 Function
0 - Off
The current limit value controller functions and the intelli-
gent current limits have been deactivated.
1 - On The current limit value controller is active.
226 Operating Instructions ACU 06/13