Ramp-Function Generator - Siemens SINAMICS G120C Operating Instructions Manual

Advanced commissioning
8.18 Setpoint processing
8.18.6

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.
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).
Table 8-53
Parameter
p1120
p1121
286
Additional parameters to set the extended ramp-function generator
Description
Ramp-function generator, ramp-up time (factory setting: 10 s)
Accelerating time in seconds from zero speed up to the maximum speed p1082
Ramp-function generator, ramp-down time (factory setting: 10 s)
Braking time in seconds from the maximum speed down to standstill
Operating Instructions, 02/2023, FW V4.7 SP14, A5E34263257B AK
SINAMICS G120C Converters