Below is examples of various commutation forms different driving ways of a brushless motor:

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Such a motor can be BLDC or PMSM. My question is: imagine we set the motor position to a fixed stationary non moving angle so that the shaft is not rotating after it arrived to the set position. In this case(when the shaft is fixed and not moving) does that mean the voltages across the field windings will be constant? And if it is BLDC with 6 step commutation does that mean the driver can only set the position at 6 different positions or can it provide more positions by varying the voltage levels at the windings?


It depends on the driver. Sometimes the driver provides a holding current that is lower than the drive current, to help ensure the motor doesn't move when you don't want it to.

Yes, the 6 step type is limited to 6 steps. It can't create more than that because this is saying the driver is only capable of supplying 6 different voltages. More goes into it than that, but that is the simple version.


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