12/16
Operating Instructions ACU
123
11.2.3
Magnetizing Current
The
Rated Magnetising Current
716
is a measure of the flux in the motor and thus of the voltage
which is present at the machine in no-load condition depending on the speed. The guided
commissioning determines this value at approx. 30% of the
Rated Current
371
. This current can be
compared to the field current of an externally excited direct current machine.
In order to optimize the sensorless field-oriented control system, the machine must be operated
without load at a rotational frequency which is below the
Rated Frequency
375
. The accuracy of the
optimization increases with the adjusted
Switching Frequency
400
and when the drive is in no-load
operation. The flux-forming actual current value
Isd
215
to be read out should roughly match the
set
Rated Magnetising Current
716
.
The field-oriented control with speed sensor feedback uses the parameterized
Rated Magnetising
Current
716
for the flux in the motor.
The dependence of the magnetizing on the frequency and voltage at the corresponding operating
point in question is taken into account by a magnetizing characteristic. The characteristic is
calculated via three points, in particular in the field weakening area above the rated frequency. The
parameter identification has determined the magnetizing characteristic and set the parameters
Magnetising Current 50% Flux
713
,
Magnetising Current 80% Flux
714
and Magnetising Current
110% Flux
715
.
Parameter
Setting
No.
Description
Min.
Max.
Factory setting
713 Magnetizing current 50%
1.00 %
50.00 %
31.00 %
714 Magnetizing current 80%
1.00 %
80.00 %
65.00 %
715 Magnetizing current 110%
110.00 %
197.00 %
145.00 %
716 Rated magnetizing current
0.01
I
FIN
o
I
FIN
0.3
I
FIN
11.2.4
Rated slip correction factor
The rotor time constant results from the inductance of the rotor circuit and the rotor resistance. Due
to the temperature-dependence of the rotor resistance and the saturation effects of the iron, the
rotor time constant is also dependent on temperature and current. The load behavior and thus the
rated slip depend on the rotor time constant. The guided commissioning determines the machine
data during the parameter identification and sets the parameter
Rated Slip Correction Factor
718
accordingly. For the fine adjustment or a check of the rotor time constant, proceed as follows: Load
the machine at fifty percent of the
Rated Frequency
375
. As a result, the voltage must be
approximately fifty percent of the
Rated Voltage
370
with a max. deviation of 5%. If this is not the
case, the correction factor must be changed accordingly. The larger the correction factor is set, the
stronger the voltage drop when the machine is loaded. The software-calculated rotor time constant
value can be read via actual value
Act. Rotor Time Constant
227
. The adjustment should be done at
a winding temperature which is also reached during normal operation of the motor.
Parameter
Setting
No.
Description
Min.
Max.
Factory setting
718 Rated slip correction factor
0.01 %
300.00 %
100.00 %
Summary of Contents for active cube 201
Page 1: ...ACTIVE CUBE Operating Instructions Frequency inverter 230 V 400 V 0 25 kW 132 kW...
Page 2: ......
Page 45: ...12 16 Operating Instructions ACU 45...
Page 181: ...12 16 Operating Instructions ACU 181...
Page 284: ......