Commissioning
Operating mode
V/f characteristic control
6
6.8
6.8.1
6.8-4
EDSVF9333V EN 3.0-06/2005
6.8.1 V/f characteristic control
The output voltage of the controller follows a defined characteristic. At low
output frequencies, the characteristic can be boosted. It can be adapted to
different load profiles.
ƒ Linear characteristic for drives with constant load torque over the
speed.
ƒ Quadratic characteristic for drives with quadratic load torque over the
speed:
– Quadratic V/f characteristics are preferably used in centrifugal pump
and fan drives. However, it must be checked whether your pump or
fan drive can be operated in this operating mode!
–Ifyourpumporfandrivecannotbeusedfortheoperationwitha
quadratic V/f characteristic, the linear V/f characteristic or vector
control mode must be used.
01
0
C0089
C0090
100 %
N
n
n
U
min
U
out
01
0
C0089
C0090
100 %
N
n
n
U
min
U
out
9300vec085 9300vec086
Fig. 6.8-3 Linear and square-law V/f characteristic
Codes for parameter setting
Code Possible settings IMPORTANT
No. Name Lenze Selection
C0006
OP MODE 5
Selection of the operating mode
forthemotorcontrol
1 vector ctrl Vector control
without or with
speed feedback
In case of the first selection enter
the motor data and identify them
with C0148.
6.8-8
5 V/f V/f characteristic
control
Commissioning without
identification of the motor data is
possible
z Advantage of identification
with C0148: Improved smooth
running at low speeds
6.8-4
C0014 V/f charact. 0
Characteristic in the V/f
characteristic control mode
8.2-25
0 Linear Linear V/f characteristic
1 square Square V/f characteristic
C0015 Rated freq 50 10 {1 Hz} 5000 V/f-rated frequency
In C0015 you can set a base
frequency which differs from the
rated motor frequency (C0089)
z Lenze setting: C0015 = C0089
z Changing C0086 or C0089
overwrites the value in C0015
8.2-25
Description