Siemens sinamics G120 Operating Instructions Manual page 222

Advanced commissioning
6.4 Setpoint calculation
Setting the extended ramp-function generator
Procedure
Proceed as follows to set the extended ramp-function generator:
1. Enter the highest possible speed setpoint.
2. Switch on the motor.
3. Evaluate your drive response.
– If the motor accelerates too slowly, then reduce the ramp-up time.
– If the motor accelerates too fast, then extend the ramp-up time.
– Increase the initial rounding if the acceleration is jerky.
– We recommend that you set the final rounding to the same value as the initial
4. Switch off the motor.
5. Evaluate your drive response.
– If the motor decelerates too slowly, then reduce the ramp-down time.
– Extend the ramp-down time if the motor is braked too quickly or the converter goes
6. Repeat steps 1 ... 5 until the drive behavior meets the requirements of the machine or
plant.
You have set the extended ramp-function generator.
222
An excessively short ramp-up time means that the motor will reach its current limiting
when accelerating, and will temporarily not be able to follow the speed setpoint. In this
case, the drive exceeds the set time.
rounding.
The minimum ramp-down time that makes sense depends on your particular
application. Depending on the Power Module used, for an excessively short ramp-
down time, the converter either reaches the motor current, or the DC link voltage in
the converter becomes too high. Depending on the converter setting, the real braking
time exceeds the set ramp-down time, or the converter goes into a fault condition
when braking.
into a fault condition when braking.
Operating Instructions, 01/2016, FW V4.7 SP6, A5E31759476B AE
Converter with CU250S-2 Control Unit