Advanced commissioning
7.9 Setpoint calculation
SIMATIC ET 200pro FC-2 converter
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Operating Instructions, 04/2018, FW V4.7 SP10, A5E34257324B AF
3.
Evaluate your drive response.
–
If the motor accelerates too slowly, then reduce the ramp-up time.
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.
–
If the motor accelerates too fast, then extend the ramp-up time.
–
Increase the initial rounding if the acceleration is jerky.
–
In most applications, it is sufficient when the final rounding is set to the same value as
the initial rounding.
4.
Switch off the motor.
5.
Evaluate your drive response.
–
If the motor decelerates too slowly, then reduce the ramp-down time.
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 inverter either reaches the motor current, or the DC link voltage in the
inverter becomes too high.
–
Extend the ramp-down time if the motor is braked too quickly or the inverter goes into
a fault condition when braking.
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.
❒
Changing the ramp-up and ramp-down times in operation
The ramping up and down time of the ramp-function generator can be changed during
operation. The scaling value can come, e.g. from the fieldbus.
Table 7- 23 Parameters for setting the scaling
Parameter
Description
p1138
Up ramp scaling (factory setting: 1)
Signal source for scaling the acceleration ramp.
p1139
Deceleration ramp scaling (factory setting: 1)
Signal source for scaling the deceleration ramp.