Ramp-Function Generator - Siemens SINAMICS S150 Operating Instructions Manual

Setpoint channel and closed-loop control
7.2 Setpoint channel
7.2.5

Ramp-function generator

Description
The ramp-function generator limits the rate at which the setpoint changes when the drive is
accelerating or decelerating. This prevents excessive setpoint step changes from damaging
the drive train. Additional rounding times can also be set in the lower and upper speed
ranges to improve control quality and prevent load surges, thereby protecting mechanical
components, such as shafts and couplings.
The ramp-up and ramp-down times each refer to the maximum speed (p1082). The rounding
times that can be set can prevent the actual speed value from being overshot when the
setpoint is approached, thereby improving control quality.
Notice: if rounding times are too long, this can cause the setpoint to be overshot if the
setpoint is reduced abruptly during ramp-up. Rounding is also effective in the zero crossover;
in other words, when the direction is reversed, the ramp-function generator output is reduced
to zero via initial rounding, the ramp-down time, and final rounding before the new, inverted
setpoint is approached via start rounding, the ramp-up time, and end rounding. Rounding
times that can be set separately are active in the event of a fast stop (OFF3). The actual
ramp-up/ramp-down times increase with active rounding.
The rounding type can be set using p1134 and separately activated/deactivated using
p1151.00 in the zero passage.
Signal flow diagram
Figure 7-3
Function diagram
FP 3060
FP 3060
264
Signal flow diagram: Ramp-function generator
Simple ramp-function generator
Extended ramp-function generator
Drive converter cabinet units
Operating Instructions, 07/07, A5E00288214A