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

Advanced commissioning
7.20 Motor control
• Line impedance
• Actual motor torque
The maximum possible output voltage as a function of the input voltage is provided in the
technical data.
7.20.2.2

Selecting the U/f characteristic

Table 7-8 Linear and parabolic characteristics
Requirement Application examples Remark
The required tor‐ Conveyor belts, roller
que is independent conveyors, chain con‐
of the speed veyors, eccentric worm
pumps, compressors,
extruders, centrifuges,
agitators, mixers
The required tor‐ Centrifugal pumps, ra‐
que increases with dial fans, axial fans
the speed
Table 7-9 Characteristics for special applications
Requirement Application examples Remark
Applications with a Centrifugal pumps, ra‐
low dynamic re‐ dial fans, axial fans
sponse and con‐
stant speed
The converter must Drives in the textile sec‐
maintain the motor tor
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.
286
Technical data (Page 411)
-
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 un‐
changed 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.
SINAMICS G115D Wall Mounted distributed drive
Operating Instructions, 07/2023, FW V4.7 SP14, A5E52808211A AA
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 fre‐ p1300 = 5
quency or
characteris‐ p1300 = 6
tic
Adjustable p1300 = 3
characteris‐
tic
Independ‐ p1300 = 19
ent voltage
setpoint