1 defining the v/f characteristic, Defining the v/f characteristic, 5motor interface – Lenze 9400 User Manual
Page 182
5
Motor interface
5.6
V/f control (VFCplus)
182
Lenze · Servo-Inverter 9400 HighLine · Reference manual · DMS 10.0 EN · 11/2013 · TD05/06
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5.6.1.1
Defining the V/f characteristic
Linear/square-law characteristic
serves to select the shape of the characteristic to adjust the characteristic to different load
profiles:
• Linear characteristic for drives with constant load torque over the speed.
• Square-law characteristic for drives with a linear or square-law load torque over the speed:
• Square-law V/f characteristics are mostly used in centrifugal pump and fan drives. However,
it must be checked in each individual case if your pump or fan drive can be used in this
operating mode!
• If your pump or fan drive is not suitable for operation with a square-law V/f characteristic,
you have to use the linear or user-definable V/f characteristic or the sensorless vector control
instead of the V/f control.
[5-16] Linear/square-law V/f characteristic
• The calculation of the characteristic considers the rated motor voltage (
) and the V/f
base frequency (
).
Short overview: Parameters for V/f characteristic
C00090: Rated motor voltage
C00951: V/f base frequency
0
0
C00951
f
soll
0
0
C00951
f
soll
U
C00090
U
C00090
Parameter
Info
Lenze setting
Value Unit
VFC: V/f characteristic shape
Linear (V/f)
VFC: V/f base frequency
50 Hz
VFC: Frequency interpol. point n
VFC: Voltage interpol. point n
VFC: Activat. interpol. point n