Hi there, I´m with some troubles controlling a bldc sensorless motor. I would like to know if anyone knows how to preposition de motor in order to start from a position that some magnets are aligned with the coils of the motor to execute the sequences perfectly.
Thanks!

 

The Motor should naturally "Cog", ( stick to ), each pole as it is rotated with no Power.

There may be from 3 to 12 poles in the Motor, some have even more.

Temporarily connecting Power to only a single Winding, will cause the Motor to
instantly align with the Poles, if it is not already aligned with them at rest.

If You need the Motor-Shaft to go to a specific "Rotational-Position",
this is more complex,
and will require some kind of Sensor on the Shaft of the Motor.
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I assume you are looking to implement commutation using a sensorless method, typically done by initially exercising the rotor slightly in order to detect rotor position.
From then on, the rotor is synchronized.
I have only ever done sensored commutation, but I think Picmicro/Microchip etc, has some application notes on it.