description of parameters
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2.5.5
Voltage at field weakening point
Above the frequency at the field weakening point, the output voltage remains at the set
maximum value. Below the frequency at the field weakening point, the output voltage
depends on the setting of the U/f curve parameters. See parameters
(nominal voltage and nominal frequency of the
motor) are set the parameters 2.5.4 and 2.5.5 are automatically given the
corresponding values. If you need different values for the field weakening point and the
maximum output voltage, change these parameters after setting the parameters 2.1.1
and 2.1.2.
2.5.6
U/f curve, middle point frequency
If the programmable U/f curve has been selected with the parameter
parameter defines the middle point frequency of the curve. See Figure 7.
2.5.7
U/f curve, middle point voltage
If the programmable U/f curve has been selected with the parameter
parameter defines the middle point voltage of the curve. See Figure 7.
2.5.8
Output voltage at zero frequency
If the programmable U/f curve has been selected with the parameter
parameter defines the zero frequency voltage of the curve. See Figure 7.
2.5.9 Switching
frequency
Motor noise can be minimised using a high switching frequency. Increasing the
switching frequency reduces the capacity of the frequency converter unit.
The range of this parameter depends on the size of the frequency converter:
2.5.10 Overvoltage
controller
2.5.11 Undervoltage
controller
These parameters allow the under-/overvoltage controllers to be switched out of
operation. This may be useful, for example, if the mains supply voltage varies more
than –15% to +10% and the application will not tolerate this over-/undervoltage. In this
case, the regulator controls the output frequency taking the supply fluctuations into
account.
Note: Over-/undervoltage trips may occur when controllers are switched out of
operation.
0 Controller switched off
1 Controller switched on
2.5.12.
Measured RS voltage drop
Measured Voltage drop at stator resistance between two phases of the motor with
nominal current of motor.
