Lenze L-force 8400 BaseLine D - Page 75

Firmware 03.00 - DMS EN 5.0 - 07/2009 L 75
8400 BaseLine D | Software Manual
Motor control (MCTRL)
Selection of the operating mode
In case of the V/f characteristic control, the motor voltage of the inverter is detected by
means of a linear or square-law characteristic depending on the field frequency or motor
speed to be generated. The voltage follows a preselected characteristic.
[5-1] Principle of a linear and quadratic V/f characteristic
Generally, two different characteristic shapes can be defined:
 Linear V/f characteristic for drives with a constantly running and speed-independent
load torque
 Quadratic characteristic for drives with a load torque increasing quadratically with the
speed. Quadratic V/f characteristics are mainly used in centrifugal pumps and fan
drives.
8400vec085 / 8400vec086
01
0
100 %
N
n
n
U
min
U
out
01
0
100 %
N
n
n
U
min
U
out