What are the differences between Flying Start-1 and Flying Start-2 in iS7

What are the differences between Flying Start-1 and Flying Start-2 in iS7

1. Flying Start-1
- Older method for Speed Search.
- Speed search is implemented by controlling the output current at or below the speed search current(CON-72) value.
- Advantage : Stable at the low speed below 10Hz if the direction is same.
- Disadvantage : If the direction is different, this method cannot detect the direction.

2. Flying Start-2
- Newer method for Speed Search.
- Speed search is implemented by PI control of ripple current caused by the back electromotive force(EMF).
- Advantage : The Performance of the Speed search is good regardless of the direction. The VFD can find the direction from the back electromotive force.
- Disadvantage : It could be unstable at the low speed below 10Hz~15Hz  due to the back electromotive force being too small.