How to smooth start a 3-phase induction motor ?
When we want to smooth the starting of ” AC Induction Motor ” we can use the Electronic Starters where we have 2 possibilities, that are :
– By ” Variable Speed Drive “, or :
– By ” Soft Starter “
The main difference between them is :
with ” Soft Starter ” we can only ” Run & Stop ” smootly the motor, but after running the motor will run absolutly at his nominal speed, where with ” Variable Speed Drive ” we have the same advantage, plus we can after running change the spped of the motor. So, if you don't need to change the speed the best solution is using the ” Soft Starter “, but if you should change the motor's speed you should use the ” Variable Speed Drive “.
Noting that :
– There's up to 630kW-415VAC as ” Soft Starter ” or ” Variable Speed Drive “.
– The Vriable Speed Drives generate the Harmonics.