in the name of god
hi every body
what is benefit of brush less dc motor and brush less ac motor. And when we use bldc and when blac? What is different of them? I know that bldcs have trapezial emf and blacs have sin emf.

Point 1: The brushless AC motor (BLAC) is similar to the BLDC motor but the back EMF is sinusoidal rather than trapezoidal.
Point 2:As we know Torque in a permanent magnet motor is produced by the product of the current with the back EMF summed over the three phases.
In a BLDC motor :The BLDC motor has a trapezoidal back EMF and so the strategy is to apply a three phase square wave current to the stator windings.
In a BLAC motor :The stator is driven with a sinusoidal current that is aligned with the back EMF.
The above is the main difference
Hope I have answered your question.
All the best