Selecting The U/F Characteristic; Advanced Commissioning - Siemens SINAMICS G110M Operating Instructions Manual

Advanced commissioning

6.5 Motor control
The value of the output voltage at the rated motor frequency also depends on the following
variables:
● Ratio between the inverter size and the motor size
● Line voltage
● Line impedance
● Actual motor torque
The maximum possible output voltage as a function of the input voltage is provided in the
technical data.
6.5.1.2

Selecting the U/f characteristic

Table 6- 29 Linear and parabolic characteristics
Requirement Application examples
The required Conveyor belts, roller
torque is inde- conveyors, chain con-
pendent of the veyors, eccentric worm
speed pumps, compressors,
extruders, centrifuges,
agitators, mixers
The required Centrifugal pumps,
torque increases radial fans, axial fans
with the speed
Table 6- 30 Characteristics for special applications
Requirement Application examples
Applications with a Centrifugal pumps,
low dynamic re- radial fans, axial fans
sponse and con-
stant speed
The inverter must Drives in the textile
keep the motor sector
speed constant
under all circum-
stances.
Freely adjustable -
U/f characteristic
U/f characteristic -
with independent
voltage setpoint
180
Technical data (Page 305)
Remark
-
The inverter equalizes the voltage drops
across the stator resistance. Recom-
mended for motors less than 7.5 kW.
Precondition: You have set the motor data
according to the rating plate and have
performed the motor identification after
the basic commissioning.
Lower losses in the motor and inverter
than for a linear characteristic.
Remark
The ECO mode results in additional ener-
gy saving when compared to the parabolic
characteristic.
If the speed setpoint is reached and re-
mains unchanged for 5 seconds, the in-
verter again reduces its output voltage.
When the maximum current limit is
reached, the inverter only reduces the
stator voltage but not the speed.
-
The interrelationship between the fre-
quency and voltage is not calculated in
the inverter, but is specified by the user.
Characteristic
Linear
Linear with Flux
Current Control
(FCC)
Parabolic
Characteristic
ECO mode
Precise fre-
quency charac-
teristic
Adjustable char-
acteristic
Independent
voltage setpoint
Distributed converter for SIMOGEAR geared motors
Operating Instructions, 06/2016, FW V4.7.6, A5E31298649B AG
Parameter
p1300 = 0
p1300 = 1
p1300 = 2
Parameter
p1300 = 4
or
p1300 = 7
p1300 = 5
or
p1300 = 6
p1300 = 3
p1300 = 19