Siemens SINAMICS S120 Function Manual page 206

Vector control
Differences with respect to vector U/f control
Compared with vector U/f control, vector control offers the following benefits:
● Stability for load and setpoint changes
● Short rise times for setpoint changes (→ better control behavior)
● Short settling times for load changes (→ better response to disturbances)
● Acceleration and braking are possible with maximum settable torque
● Motor protection due to variable torque limitation in motor and regenerative mode
● Drive and braking torque controlled independently of the speed
● Maximum breakaway torque possible at speed 0
The basic features and properties of the SERVO and VECTOR control modes are compared
in the following table.
Table 6-1 Comparison: Servo control/vector control
Subject
Typical applications
Maximum number of drives that can
be controlled by one Control Unit
To be observed:
Chapter "Rules for wiring with
DRIVE-CLiQ (Page 845)"
further down in this document
Dynamic response
204
Servo control
● Drives with highly dynamic motion
control
● Drives with high speed and torque
accuracy
(servo synchronous motors)
● Angular-locked synchronism with
isochronous PROFIdrive
● For use in machine tools and clocked
production machines
● High output frequency
● 1 infeed unit + 6 drives
(with current controller sampling times
125 μs or
speed controller sampling times
125 μs)
● 1 infeed unit + 3 drives
(with current controller sampling times
62.5 μs or
speed controller sampling times
62.5 μs)
● 1 infeed unit + 1 drive
(with controller sampling times
31.25 μs or speed controller sampling
times 62.5 μs)
● Mixed operation, servo control with
125 µs with U/f, max.11 drives
High
Vector control
● Speed and torque-controlled drives
with high speed and torque accuracy,
particularly in operation without an
encoder (sensorless operation)
● 1 infeed unit + 3 drives
(with current controller sampling times
250 μs or
speed controller sampling times of
1 ms)
● 1 infeed unit + 6 drives
(with current controller sampling times
400 μs/500 μs or
speed controller sampling times
1.6 ms/2 ms)
● U/f control:
1 infeed unit + 12 drives
(with current controller sampling times
500 μs or
speed controller sampling times
2000 μs)
● Mixed operation, vector control with
500 µs with U/f, max.11 drives
Medium
Function Manual, 06/2019, 6SL3097-5AB00-0BP2
Drive functions