Due to the high power density the interior permanent magnet synchronous motors (IPMSM) are widely used as traction drives. However this machine principle has the disadvantage of low energy efficiency in high speed range. An alternative machine principle is the electrically excited synchronous motor (EESM). It enables an additional degree of freedom to control the motor torque efficiently. In this paper an energy efficient control is implemented for an EESM which is designed for the traction application.