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15.8.3.2
Current-control
For improving the startin, the stopping as well as the travelling with a slow speed, the motor will be
energised with a minimum current (Parameter
Controller/I_IxR
). With the parameters FADE1 and
FADE2 the current can be set depending on the frequency (f) of the rotating
fi
eld in the stator.
f < FADE1:
If the frequency of the rotating
fi
eld in the stator is less than FADE1 the motor will be energised with
100% of I_IxR.
f > FADE2:
If the frequency of the rotating
fi
eld in the stator is greater than FADE2 the current I_IxR is 0
FADE1 < f < FADE2:
If the frequency of the rotating
fi
eld is between FADE1 and FADE2 the current-control depends on the
characteristic curve: the higher the frequency the lower is the current impression.
The characteristic curve is de
fi
ned by the values for FADE1 and FADE2.
I_IxR
FADE1
f
100 %
FADE2
Fader-function for the current-control
15.8.3.3
Slip-compensation
With asynchronous motors the slip (difference between synchronous speed and asynchronous
speed) is proportional to the load of the motor and therefore porportional to the motor current. This
leads to different travel speeds in upwards and downwards direction with the same load.
Example:
The nominal speed of a motor is 1430 rpm. With empty car in downwards direction the speed is
1430 rpm. In upwards direction the speed is 1570 rpm.
The difference of 140 rpm will be settled by the slip-compensation.
The slip-compensation will be activated with the parameter
Controller/s_COMP=On
.
Control
|
-
"
s_COMP
On
|
-
"
On
U/F: Slip comp.
Functionality:
The motor current is recorded by a
fi
lter (parameter "s_FIL"). Proportional to the measured motor
current:
•
the slip-frequency will be added or subtracted to the output frequency of the U/f-characteristic curve
•
voltage will be added dto the output voltage of the U/f-characteristic curve
Original operating instructions
ZAdyn4B 110-180
Special functions
R-TBA15_01-GB 2014 Index 005
Part.-No. 00163453-GB
171/200
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