Different methods for reducing detent force in a permanent magnet linear synchronous motor

In almost every permanent magnet (PM) excited machine, detent forces arise, which are caused by the permanent magnets in connection with the iron core. In case of permanent magnet linear synchronous motors (PMLSM), two sources of detent forces have to be taken into account: Cogging forces based on the stator slots and detent forces caused by the end effects. Both forces have a negative influence on the operating behavior of PM motors. Therefore it is necessary and important to consider these effects during the motor design.