Siemens SINAMICS S120 Installation And Start-Up Manual page 26

System Overview
Comparison: servo <-> vector
Table 1-1
Motor identification
(third-party motors)
and speed
controller
optimization
V/f control
Sensorless torque
control
Field-weakening
range for induction
motors
Maximum output
frequency with
closed-loop control
Note:
Note the derating characteristics in the Equipment Manuals.
Response during
operation at
thermal limit of
motor
Speed setpoint
channel
(ramp-function
generator)
Parallel connection
of Power Modules
1-26
Servo versus vector, continued
Servo
No
Diagnosis mode
No
v 16 * field-weakening threshold
speed (with encoder)
v 5 * field-weakening threshold
speed (without encoder)
650 Hz with 125 µs / 4 kHz
Reduction of current setpoint or
shutdown
Optional (reduces the number of
drives from 6 to 5 Motor Modules
with a sampling time for current
controller of 125 µs / speed
controller 125 µs)
No
SINAMICS S120 Installation and Start-Up Manual, 12/04 Edition
Vector
Yes
Yes (different characteristics)
Yes (controlled at low speeds)
v 5 * rated motor speed
300 Hz with 250 µs / 4 kHz or
with 400 µs / 5 kHz
Reduction of pulse frequency
and/or current setpoint or
shutdown (not with parallel
connection/sinusoidal filter)
Standard
Booksize:
No
Chassis:
Yes
E Siemens AG, 2004. All rights reserved
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