Lappeenrannan Teknillinen Yliopisto

Abb Schweiz Ag

Lappeenrannan-lahden Teknillinen Yliopisto Lut

Rafal Jastrzebski

Alexander Smirnov

Olli Pyrhönen

Kimmo Tolsa

Tuomo Lindh

Pekko Jaatinen

An electric drive comprises a bearingless electric machine, a converter, and a control device. The stator of the electric machine has a cage winding including bars connected to a conductor ring. The control device controls the converter to supply torque generating current components to the bars so that torque is generated in accordance with electric machine control and to supply levitation current components to the bars so that the rotor of the bearingless electric machine is levitated in accordance with levitation control. The cage winding allows the currents of the bars to be controlled so that different current sheet distributions can be generated so as to generate desired torque and magnetic force.

Control device and a method for controlling an electric drive

An electrical drive includes an electrical machine, a first converter stage connected to terminals of stator phase-windings of the electrical machine, and a second converter stage connected to intermediate points of the stator phase-windings. A control device determines first component currents and second component currents so that torque is generated in accordance with electrical machine control and magnetic levitation force is directed to a rotor of the electrical machine in accordance with levitation control when portions of the phase-windings between the terminals and the intermediate points carry both the first and second component currents and the other portions of the phase-windings carry the first component currents. The reference currents for the first converter stage are determined based on the first and second component currents, and the reference currents for the second converter stage are determined based on the second component currents.

Control device and a method for controlling magnetic levitation and torque generation

A position sensor for sensing position or motion, includes: a ferrite core, and a sensor coil configured to provide a sensor signal. The sensor coil is implemented on a printed circuit board, and the ferrite core is configured to be fitted into the printed circuit board.

Position sensor

The present disclosure presents a method, a sensor comprising printed circuit board (PCB), and a sensor PCB for a capacitive sensor for sensing position or motion of a shaft comprising an electrically conducting part. The method and the sensor utilize the sensor PCB that comprises a mounting hole through which the conducting part of the shaft can be mounted, at least one capacitor electrode formed to the printed circuit board, wherein an electrode surface of the electrode extends parallel to a center axis of the mounting hole and faces the center axis.

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Lappeenranta, Finland

Rafal Jastrzebski