PERMANENT-MAGNET-EXCITED ELECTRIC MACHINE OPERATED WITHOUT A SENSOR, IN PARTICULAR FOR A FUEL CELL UNIT OF A MOTOR VEHICLE, AND A METHOD OF OPERATING A PERMANENT-MAGNET-EXCITED ELECTRIC MACHINE OPERATED WITHOUT A SENSOR

摘要

The invention relates to a permanent-magnet-excited electric machine (1) operated without a sensor, in particular for a fuel cell unit of a motor vehicle, in particular an automobile, having a stator (2) comprising a stator winding (3) and a rotor mounted rotationally movably relative to the stator (2), which rotor comprises at least one permanent magnet with a north pole region and a south pole region, and having an open- and/or closed-loop control means (5), which is coupled to the stator winding (3) and is designed to energize the stator winding (3), wherein the open- and/or closed-loop control means (5) is designed to energize the stator winding (3) when the electric machine (1) is at a standstill and the rotor may be fixed in a neutral angular position other than a dead center position as a result of said energization when at a standstill.