Curved Acceleration Characteristic (Sw 4 And Higher) - Siemens SINUMERIK 840C Installation Instructions Manual

10 Axis and Spindle Installation

10.5.4 Curved acceleration characteristic (SW 4 and higher)

10.5.4
When induction motors are used (spindle operation), allowance must be made for their speed-
dependent acceleration capability in position-controlled operation:
TorqueM
Fig. 1 Torque characteristic of induction motor
At speeds (n) above rated speed (n
the speed. Immediately above rated speed nn, there is a range of "constant power" in which
the torque (and thus also the acceleration capability) drop in proportion to 1/n. When speed n
increases further, there is a range ("breakdown limit") immediately above speed nk in which
the torque decreases in proportion to 1/(n*n).
The required parameters are selected and set in the MSD drive unit.
Setpoint
Fig. 2 Speed characteristic during acceleration (thick line)
10–66
More user manuals on
Curved acceleration characteristic (SW 4 and higher)
Constant
torque
Breakdown limit
M = const
Rated speed
), the drive acceleration capability decreases in relation to
n
Speed
n
k
n
n
T1
ManualsBase.com
Constant
power
M 1/n M 1/(n*n)
n n
n k
The obtainable linear ramp-up time constants
increase out of proportion for higher speeds
T2
© Siemens AG 1992 All Rights Reserved
09.95
n
max
Speed n
Time
6FC5197- AA50
SINUMERIK 840C (IA)