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
converter either reaches the motor current, or the DC link voltage in the converter
becomes too high.
– Extend the ramp-down time if the motor is braked too quickly or the converter 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.
❒
6.5.2.7
Dual ramp function
Overview
When operating at low speeds, pumps, e.g. submersible pumps, cannot be adequately
lubricated or cooled. This causes the pump to wear out more quickly.
To reduce wear, you can use the "dual ramp function". The "dual ramp function" shortens the
time it takes for the pump to operate below a critical speed.
Precondition
Before enabling the dual ramp function, adjust the ramp function generator.
Function description
Enabling
Connect the outputs of the dual ramp function with the scaling inputs of the ramp-function
generator
● Set p1138 = r29576
● Set p1139 = r29577
● Set p29580 = 1
Ramp up
● Converter starts ramp-up using ramp time from p1120 · p29570.
● When the actual speed r0063 > p29571, switch to ramp time from p1120 · p29572.
Ramp down
● Converter starts ramp-down using ramp time from p1121 · p29573.
● When the actual speed r0063 < p29574, switch to ramp time from p1121 · p29575.
Advanced commissioning
6.5 Setpoints and setpoint processing
SINAMICS G120X converter
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Operating Instructions, 06/2019, FW V1.01, A5E44751209B AC
