Siemens SINAMICS G120 Operating Instructions Manual page 185

Select a suitable control mode
Control mode U/f control with linear or square-law characteristic
Closed-loop con‐
● Typical settling time after a speed change:
trol characteristics
● Typical settling time after a load surge: 500 ms
● The control mode is suitable to address the
● The control mode is insensitive with respect
Application exam‐ ● Pumps, fans, and compressors with flow
ples
Motors that can be
operated
Power Modules
that can be operat‐
ed
Max. output fre‐
quency
Commissioning
● Contrary to vector control, no speed controller
Converter with the CU230P-2 Control Units
Operating Instructions, 09/2017, FW V4.7 SP9, A5E34257946B AE
Flux current control (FCC)
100 ms ... 200 ms
following requirements:
– Motor power ratings < 45 kW
– Ramp-up time 0 → rated speed
(depending on the motor power rating):
1 s (0.1 kW) ... 10 s (45 kW)
– Applications with increasing load torque
without load surges
to imprecise setting of the motor data
characteristic
Induction motors
550 Hz
has to be set
5.5 Quick commissioning with a PC
Encoderless vector control
● Typical settling time after a speed change:
< 100 ms
● Typical settling time after a load surge: 200 ms
● The vector control controls and limits the motor
torque
● Torque accuracy that can be achieved: ± 5% for
15 % ... 100 % of the rated speed
● We recommend vector control for the following
applications:
– Motor power ratings > 11 kW
– For load surges 10 % ... >100 % of the rated
motor torque
● The vector control is necessary for a ramp-up
time 0 → Rated speed (dependent on the rated
motor power): < 1 s (0.1 kW) ... < 10 s (250 kW).
● Pumps and compressors with displacement
machines
Induction, synchronous and reluctance motors
No restrictions
150 Hz with PM330 Power Module
Commissioning
240 Hz
185