| 摘要 |
The invention relates to a sensorless electric motor and a method of controlling such an electric motor, which motor comprises a permanently magnetic rotor, a stator having at least one winding, and a power stage for influencing the current flowing through the winding. As a function of a predetermined commutation duration (T_K), a commutation period is defined, during which period the direction of the magnetic field generated by current flow through the winding is not modified, during which period a commutation completion operation ( 107 ) and a commutation initiation operation ( 109 ) take place, and which period starts at a first commutation instant (t_K<SUB>N</SUB>) and ends at a second commutation instant (t_K<SUB>N+1</SUB>); preferably, commutation timing is adjusted, based upon a value of induced voltage picked up at a currently non-energized one of the winding strands, during a plateau portion ( 108 ) of a winding voltage trace, located temporally between commutation instants. |
