Abstract: An electric machine includes a stator and a rotor. The stator includes a frame structure and an electromagnetically active part inside the frame structure. The rotor includes a shaft and an electromagnetically active part for producing torque in co-operation with the electromagnetically active part of the stator. The electric machine includes bearings inside the frame structure and arranged to support the rotor rotatably with respect to the stator. A magnetic bearing module for supporting the shaft is attached to an outer surface of the frame structure so that the frame structure and the magnetic bearing module are axially successive. The magnetic bearing module is a replaceable component which is non-destructively detachable from the frame structure. Thus, the electric machine can be adapted to different mechanical loads by selecting a suitable magnetic bearing module.

Abstract: An electric machine includes a stator and a rotor. The stator includes a frame structure and an electromagnetically active part inside the frame structure. The rotor includes a shaft and an electromagnetically active part for producing torque in co-operation with the electromagnetically active part of the stator. The electric machine includes bearings inside the frame structure and arranged to support the rotor rotatably with respect to the stator. A magnetic bearing module for supporting the shaft is attached to an outer surface of the frame structure so that the frame structure and the magnetic bearing module are axially successive. The magnetic bearing module is a replaceable component which is non-destructively detachable from the frame structure. Thus, the electric machine can be adapted to different mechanical loads by selecting a suitable magnetic bearing module.

Abstract: A core element for a magnetic component includes a plurality of ferromagnetic sections for conducting a magnetic flux. Adjacent ones of the ferromagnetic sections are connected to each other with ferromagnetic isthmuses keeping the adjacent ones of the ferromagnetic sections a distance apart from each other, and/or the gaps between the ferromagnetic sections are filled with electrically insulating solid material and adjacent ones of the gaps are connected to each other via openings through the ferromagnetic sections and filled with electrically insulating solid material. The ferromagnetic sections can constitute for example a stack of ferromagnetic sheets or a bundle of ferromagnetic filaments. The core element can be manufactured by three-dimensional printing and thus it is possible to make core elements which are not possible or at least not cost effective to be made by shaping ferromagnetic sheets which are originally planar.

Abstract: Method of controlling a voltage controlled PWM (Pulse Width Modulated) frequency converter comprising a single phase rectifier bridge (10) connectable to a sinusoidal single phase supply, a DC intermediate circuit (11) and a controlled inverter bridge (12) for generating an AC output voltage with varying amplitude and frequency to a load, said inverter bridge (12) having PWM controlled semiconductor switches (V11–V16) and flywheel diodes (D11–D16) connected in inverse-parallel with the semiconductor switches, wherein the DC intermediate circuit (11) is provided with a DC capacitor unit, and wherein the frequency converter is controlled so that the supply line current (Iin) is essentially sinusoidal and in phase with the supply line voltage (Uin).