Selecting The U/F Characteristic - Siemens SINAMICS G115D Operating Instructions Manual

6.18.1.2

Selecting the U/f characteristic

Table 6- 5 Linear and parabolic characteristics
Requirement Application examples Remark
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- 6 Characteristics for special applications
Requirement Application examples Remark
Applications with a Centrifugal pumps,
low dynamic re- radial fans, axial fans
sponse and con-
stant speed
The converter must Drives in the textile
maintain the motor sector
speed constant for
the longest possi-
ble time.
Freely adjustable -
U/f characteristic
U/f characteristic -
with independent
voltage setpoint
Additional information on U/f characteristics can be found in the parameter list and in the
function diagrams of the List Manual.
SINAMICS G115D distributed drive
Operating Instructions, 12/2020, FW V4.7 SP13, A5E48681219B-002
-
The converter equalizes the voltage drops across
the stator resistance. Recommended for motors
less than 7.5 kW.
Precondition: You have set the motor data accord-
ing to the rating plate and have performed the
motor identification after quick commissioning.
Lower losses in the motor and converter than for a
linear characteristic.
If the speed setpoint is reached, and remains
unchanged for 5 seconds, then the converter
reduces its output voltage.
As a consequence, the ECO mode saves energy
with respect to the parabolic characteristic.
When reaching the maximum current limit, the
converter only reduces the output voltage, but
not the frequency.
-
The interrelationship between the frequency and
voltage is not calculated in the converter, but is
specified by the user.
Advanced commissioning
6.18 Motor control
Character- Parameter
istic
Linear p1300 = 0
Linear with p1300 = 1
Flux Cur-
rent Con-
trol (FCC)
Parabolic p1300 = 2
Character- Parameter
istic
ECO mode p1300 = 4
or
p1300 = 7
Precise p1300 = 5
frequency or
characteris- p1300 = 6
tic
Adjustable p1300 = 3
characteris-
tic
Independ- p1300 = 19
ent voltage
setpoint
257