Lenze 8400 motec - Manual (Page 98)

5 Motor control (MCTRL)
5.5 V/f characteristic control (VFCplus)
98 Lenze · 8400 motec · Reference manual · DMS 4.1 EN · 08/2013 · TD05
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5.5.2 Basic settings
The "Initial commissioning steps" listed in the table below are sufficient for a simple characteristic
control.
• Detailed information on the individual steps can be found in the following subchapters.

Tip!
Information on the optimisation of the control mode and the adaptation to the real
application is provided in chapter " Optimising the control mode ". ( 100)
Parameterisable additional functions are described correspondingly in the chapter
" Parameterisable additional functions ". ( 145)
5.5.2.1 Defining the V/f characteristic shape
In principle, three different characteristic shapes can be stipulated:
1. Linear V/f characteristic:
For drives for a constant, speed-independent load torque.
2. Quadratic V/f characteristic:
For drives with a load torque curve which is quadratic or in relation to speed. Quadratic V/f
characteristics are preferred in the case of centrifugal pumps and fan drives.
[5-1] Principle of a linear and quadratic V/f characteristic
The V/f characteristic shape is defined by selecting the corresponding motor control mode in
C00006 :
• C00006 = "6: VFCplus: V/f linear" for linear characteristic
• C00006 = "8: VFCplus: V/f quadr" for quadratic characteristic
Initial commissioning steps
1. Defining the V/f characteristic shape .
2. Defining current limits (Imax controller) . ( 99)
0 1
0
100 %
N
n
n
U min
U out
0 1
0
100 %
N
n
n
U min
U out