Siemens SINAMICS GM150 - Page 165

Speed limitation
The speed limitation is used to limit the maximum permitted speed for the complete drive train.
The drive and the load machine / process are protected from damage caused by overspeed.
Table 8-7 Parameter
Parameter Setting
p1082 Maximum speed, both directions of rotation
p1083 Speed limit in positive direction of rotation
p1086 Speed limit in negative direction of rotation
You can find additional information in function diagrams 1550 and 3050.
Ramp-function generator
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. Parameter p1115 can be used to select two ramp-function generators.
To improve the control properties with regard to load surges, set additional rounding times in
the lower and upper speed range.
The rounding times achieve the following:
● They protect mechanical components, such as shafts and couplings.
● The overshoot of the actual speed while approaching the setpoint is avoided. The control
quality is improved.
The ramp-up and ramp-down times each refer to the maximum speed (p1082).
Note
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;
When the rotational direction is reversed, the ramp-function generator output is reduced to
zero using the following parameters:
● The initial rounding
● The ramp-down time
● The final rounding
The new inverted setpoint is approached using the following parameters:
● The initial rounding
● The ramp-up time
● The final rounding
Operation
8.4 Functions
SINAMICS GM150 6SL3815-2LN41-4AA2
Operating Instructions 04/2017 165