Lenze 8200 motec frequency inverter 0.25kW-7.5kW - Manual (Page 75)

Function library
Selection of control mode, optimisation of operating behaviour
7−4
L
EDB82MV752 EN 5.2
7.1.1 V/f characteristic control
Description
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.
·
Linear characteristic for drives with constant load torque over the speed.
·
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!
– If your pump or fan drive cannot be used for the operation with a quadratic V/f
characteristic, the linear V/f characteristic or vector control mode must be used.
C0015
V [V]
out
f [Hz]
V
(100 %)
rmot
C0015
V [V]
out
f [Hz]
V
(100 %)
rmot
8200vec540 8200vec539
Fig. 7−2 Linear and square−law V/f characteristic
Codes for parameter setting
Code Possible settings IMPORTANT
No. Name Lenze Selection
C0014
v
Operating mode 2 2 V/f characteristic control V ~ f
(linear characteristic with constant V
min
boost)
·
Commissioning is possible without
identifying motor parameters
·
Advantage of identification with C0148:
– Improved smooth running at low
speeds
– V/f rated frequency (C0015) and slip
(C0021) are calculated and saved.
They must not be entered
^ 7−2
3 V/f characteristic control V ~ f 2
(square−law characteristic with constant V
min
boost)
4 Vector control In case of the first selection enter the
motor data and identify them with
C0148
Otherwise, commissioning is not
possible
When C0014 = 5, C0019 must be set = 0
(automatic DC injection brake is
deactivated)
5 Sensorless torque control with speed limitation
·
Torque setpoint via C0412/6
·
Speed limitation via setpoint 1 (NSET1−N1) if
C0412/1 is assigned, otherwise via maximum
frequency (C0011)
C0015
uSEr
V/f rated frequency 50.00 7.50 {0.02 Hz} 960.00
·
C0015 is calculated and stored under
C0148 when the motor parameters are
identified
·
Setting applies to all mains voltages
permitted
^ 7−4
^ 7−8
C0016
uSEr
V
min
boost а 0.00 {0.01 %} 40.00 а Depending on the controller
Setting applies to all mains voltages
permitted
^ 7−4