Siemens SINAMICS G120D Series - Selecting the Control Mode

Commissioning
5.2 Preparing for commissioning
5.2.2
Selecting the control mode
Suitable applications and typical control properties
U/f control or FCC (flux current con-
trol) without an encoder
Vector control without an encod-
er
Vector control with encoder
Application
examples
• Horizontal conveyor technology
(conveyor belts, roller conveyors,
chain conveyors)
• Pumps, fans, and compressors
with flow characteristic
• Horizontal conveyor technol-
ogy (conveyor belts, roller
conveyors, chain conveyors)
• Extruder
• Centrifuges
• Pumps and compressors with
displacement machines
• Vertical conveyor technolo-
gy (conveyor belts, roller
conveyors, chain convey-
ors)
• Lifters/Lowerers
• Stacker cranes
Motors that
can be oper-
ated
Induction motors Induction motors
Encoderless 1FK7 synchronous
motors
Reluctance motors
Induction motors
The rated current of the motor must lie in the range of 13 % … 100 % of the rated current of the inverter.
Properties of
closed-loop
motor control
• Responds to speed changes with
a typical settling time of
100 ms … 200 ms
• Re-
spond
s to
load
surg-
es
with a
typical
set-
tling
time of 500 ms
• U/f and FCC are suitable for the
following cases:
– For power-up times 0 → rated
speed > 2 s
– For applications with increas-
ing load torque without load
impulses
• The closed-loop control is insensi-
tive to inaccurate motor data set-
tings, e.g. the motor temperature
• The vector control responds to speed changes with a typical
settling time of < 100 ms.
• The vector control responds to
load impulses with a typical set-
tling time of 200 ms.
• The vector control is required in
the following cases:
– For power-up times 0 → rated
speed < 2 s
– For applications with fast and
high load impulses
• Typically achieves a torque
accuracy of ± 5 % for 15
% … 100 % of the rated
speed
• Extends the torque accura-
cy of ± 5 % to speeds
< 15 % of the rated speed.
Max. output
frequency
550 Hz 240 Hz
Torque con-
trol
Closed-loop torque control not possi-
ble
Torque control for speeds >
15 % of the rated speed
Torque control from speeds = 0.
Converter with control units CU240D-2
68 Operating Instructions, 04/2015, FW V4.7.3, A5E34262100B AB