Vacon 100 flow Applications Manual page 162

vacon • 160 Monitoring value and parameter descrip-
PMS Motor
When the value of parameter P3.1.2.2 (Motor type) parameter is changed to , the
parameters P3.1.4.2 (Field weakening point frequency) and P3.1.4.3 (Voltage at field weakening
point) will be automatically extended up to the limits of the drive's full output voltage, retaining the
defined U/f-ratio. This internal extension is done to avoid running the PMS motor in the field
weakening area because the PMS motor nominal voltage is typically much lower than the full output
voltage capability of the drive.
PMS motor nominal voltage typically represents the motor's back-EMF voltage at nominal
frequency, but depending on the motor manufacturer, it may represent e.g. the stator voltage at
nominal load.
This parameter gives an easy way to adjust the drive's U/f curve near to the motor's back-EMF curve
without needing to change several U/f curve parameters.
The Stator voltage adjust parameter defines the drive's output voltage in percent of the motor's
nominal voltage at the motor's nominal frequency.
The U/f curve of the drive is typically tuned slightly above the back-EMF curve of the motor. The
motor current increases the more the drive's U/f-curve differs from the motor's
back-EMF -curve.
U [V]
Stator Voltage Adjust
(50..200 %)
Field Weakening
Point Voltage
Motor Nominal
Voltage
Zero Frequency
Voltage
f [Hz]
Field
Motor Nominal
Weakening
Frequency
Point
9208.emf
Figure 48. Principle of Stator voltage adjustment
P3.1.3.1 M (ID 107)
OTOR CURRENT LIMIT
This parameter determines the maximum motor current from the AC drive. The parameter value
range differs from size to size.
When the current limit is active, the drive output frequency is decreased.
NOTE! This is not an overcurrent trip limit.
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