Siemens SINAMICS G120C - Selecting the Control Mode

Commissioning
4.2 Commissioning with BOP-2 operator panel
SINAMICS G120C converter
Getting Started, 04/2014, FW V4.7, A5E34264105B AA
35
4.2.2
Selecting the control mode
Criteria for selecting either V/f control or vector control
U/f control or FCC (flux current control)
Vector control without an encoder
Application
examples
• Pumps, fans, and compressors with flow
characteristic
• Wet or dry blasting technology
• Mills, mixers, kneaders, crushers, agitators
• Horizontal conveyor technology (conveyor
belts, roller conveyors, chain conveyors)
• Basic spindles
• Pumps and compressors with displacement
machines
• Rotary furnaces
• Extruder
• Centrifuge
Motors that can be
operated
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
• The closed-loop control is insensitive to
inaccurate motor data settings, e.g. the
motor temperature
• Can be commissioned with just a few
settings.
• Responds to speed changes with a typical
settling time of 100 ms … 200 ms
• Responds to load surges with a typical
settling 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 increasing load
torque without load impulses
• The vector control makes highly efficient use of
the power module, the motor and the
mechanical system (95% of the line voltage).
• 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 settling time of 20 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
– For heavy duty starting using ≤ 90 % of the
stall torque of the motor
• Vector control typically achieves a torque
accuracy of ± 5 % for 10 % … 100 % of the
rated speed
Max. output
frequency
240 Hz 200 Hz