6. Control Functions and Parameter Settings
6-77
6-7-4 Exciting current control
The exciting current is controlled to establish the secondary flux. A current reduction process in the
constant output range or during voltage saturation, and high-speed magnetising control to raise the
secondary flux at a high speed are also carried out.
Parameter
No.
Parameter
Function
B32-0
Speed flux control
selection
This is the control selection for magnetising the
secondary flux to a high speed when starting operation.
Select this to increase the motor speed even slightly
when starting operation.
B32-2
Voltage saturation
compensation selection
If the output voltage in control is larger than the voltage
that can be output by the inverter, select this control to
limit the exciting current to prevent the current or torque
from hunting.
Select this when raising the output voltage to near the
input voltage, or when the input voltage changes.
Note that if voltage saturation occurs, some torque ripple
will occur. In this case, lower the B01-9 no-load voltage
setting to avoid voltage saturation.
B33-x
Table reference speed
This is the reference speed for changing the
compensation amount according to the operation speed.
Set as shown below to operate to the constant output
range.
B34-x
M fluctuation
compensation
This compensates the exciting inductance fluctuation
according to the B33 table reference speed.
Set the compensation table so that the output voltage is
constant during no-load operation through the entire
operation range.
*
This is adjusted by the automatic tuning mode 4. (B19-
0)
<Setting the table reference speed>
M' fluctuations greatly immediately after entering the constant output range, so set using the following
diagram as a reference. (The base speed is 1.)
M ' flu ctuation
coefficien t 1 00%
spee d
O pera tio n ran ge
1.4
1.2
1.7
2
1.1
1
0.3
0.6
Setting the reference speed table
