6.5.2.6
Ramp-function generator
The ramp-function generator in the setpoint channel limits the rate change of the speed setpoint
(acceleration). A reduced acceleration reduces the accelerating torque of the motor. As a
consequence, the motor reduces the stress on the mechanical system of the driven machine.
The extended ramp-function generator not only limits the acceleration, but by rounding the
setpoint, also acceleration changes (jerk). This means that the motor does not suddenly
generate a torque.
Extended ramp-function generator
The ramp-up and ramp-down times of the extended ramp-function generator can be set
independently of each other. The optimal times depend on the application, and can lie in the
range from a few 100 ms to several minutes.
5DPSXSWLPH
5DPS
GRZQWLPH
(IIHFWLYHUDPSXS
WLPH
(IIHFWLYHUDPSGRZQ
WLPH
0D[LPXP
VSHHG
\
W
[
[
\
W
[
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[
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W
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Initial and final rounding permit smooth, jerk-free acceleration and braking.
The ramp-up and ramp-down times of the motor are increased by the rounding times:
● Effective ramp-up time = p1120 + 0.5 × (p1130 + p1131).
● Effective ramp-down time = p1121 + 0.5 × (p1130 + p1131).
Advanced commissioning
6.5 Setpoints and setpoint processing
SINAMICS G120X converter
Operating Instructions, 06/2019, FW V1.01, A5E44751209B AC
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