[brian_]

I am new to electric cars so this question might appear childish (Sorry for that). I hope a positive answer from the community.
Which type of motor is more recommended, dc brushless or induction? I would like a technical answer. and which one is more efficient and recommended?

Some basic education is in order, and I'm not convinced that this sort of discussion is the way to do it, but...

Brushless motors are fundamentally AC, although that's the start of an argument about terminology. Perhaps you could clarify what you think a "DC brushless" motor means.

If you are asking about the difference between

• a synchronous 3-phase AC motor with permanent magnet (PM) rotor, and
• an asynchronous 3-phase AC motor with induction rotor

then I think the consensus of all EV manufacturers is that PM is a bit more efficient, but also more expensive to manufacture. While details of control are different, inverters are essentially the same and the logic controllers are comparable in cost and complexity. The induction motor is fundamentally always slipping a bit (the rotor does not rotate as fast as the magnetic field from the stator windings, which is why it is "asynchronous"), and losing some power as a result.

If by "DC brushless" you mean a motor which is driven with square-wave power on three input terminals (not 3-phase sinusoidal AC), then that will certainly be less efficient and less effective than a normal 3-phase AC motor. This probably doesn't matter, because unless you are building something small (light motorcycle, for instance), you're unlikely to find a motor of this type with adequate power.