Abb Schweiz Ag

Abb Research Ltd.

Abb Technology Ag

Yujing Liu

Darren Dale Tremelling

Dezheng Wu

Steven Englebretson

Se Young Yoon

Simon E Mushi

Christer Hallin

Sjoerd Bosga

Peter Löfgren

Mehanathan Pathmanathan

Robert Chin

Veli-Matti Leppänen

Pierluigi Tenca

Peter L&ouml;fgren

Veli-Matti Leppanen

Chun Yuan Gu

Wenliang Chen

Hongyang Zhang

Djordje Savinovic

Frédéric Tholence

Djorde Savinovic

Jan-Eric Lethagen

A commutation circuit includes a coil connected to an H bridge, the H bridge including four main switches for reversing polarity and a resulting coil current in the coil. The commutation circuit further includes a voltage source configured to generate a bypass current, and at least one auxiliary switch for controlling the bypass current to thereby decrease a switch current through at least one of the main switches. By generating an appropriate bypass current with help of a voltage source, a switch current through a desired main switch in a leading state can be decreased and eventually brought to zero. Zero current in its turn enables the use of thyristors as main switches as it results in the thyristors to be turned off automatically. Furthermore, decreased switch current at the switching moment reduces switching losses even in different types of switches such as GTOs and IGBTs.

High efficiency commutation circuit

A rotating electrical machine including a stator or rotor including a plurality of serially connected switching cells. Each switching cell includes a winding subsection and a current reverser arranged to controllably alter a current direction through the winding subsection, and each current reverser includes a capacitor arranged to form a resonant circuit in cooperation with the winding subsection.

Rotating electrical machine and corresponding method

Rotating machines and rotors therefor are disclosed. The bearings may be magnetic bearings configured to magnetically levitate the rotor. The rotors may include a hollow fiber-reinforced composite shaft and a magnetic bearing rotor core disposed on the shaft and configured for use with the magnetic bearing. In some examples, the rotating machines may be electrical machines.

Rotors for rotating machines with hollow fiber-reinforced composite shaft

Rotors for electrical machines and methods of fabricating the same are disclosed. Electrical machine rotors may include a hollow non-magnetic shaft, an active region, and a plurality of coolant passages extending within the active region. The hollow non-magnetic shaft may extend along an axis and have an exterior surface that defines a shaft space extending along the axis. At least a portion of the active region may be disposed within the shaft space.

Electrical machine rotors

A synchronous electrical motor includes a rotor with a DC field winding. An exciter is configured to energize the DC field winding by generating a DC current in a first direction across the DC field winding when activated. A control system is configured to control a current flow across the DC field winding, the control system including a field discharge resistor and a by-passing circuitry. The by-passing circuitry is configured to implement a first by-passing to electrically by-pass the field discharge resistor during a current flow in the first direction across the DC field winding, and to implement a second by-passing to electrically by-pass the field discharge resistor during a current flow in a second direction across the DC field winding. The control system is able to direct all the DC current generated by the exciter to flow across the DC field winding.

System and method for controlling a synchronous motor

A device for heat treatment of an object comprises a susceptor ( ) having walls ( ) surrounding an inner room ( ) adapted to receive the object and Rf-field radiating means ( ) arranged outside the walls and adapted to heat the walls and by that said object. Said means comprises at least two coils ( ) with at least one turn each following upon each other in a longitudinal direction of the susceptor and a current source ( ) arranged to cause a current to flow in each coil in a direction of rotation around the susceptor walls opposite to that of the other coil for heating said walls.

Device and a method for heat treatment of an object in a susceptor

A device for epitaxial growth of objects by Chemical Vapor Deposition on a substrate comprises a susceptor adapted to receive the substrate and members for heating walls of the susceptor surrounding the substrate and thereby the substrate and a gas mixture fed to the substrate for the growth. The device comprises also members for holding the substrate in the path of the gas mixture through the susceptor at a distance from internal walls thereof.

Method and a device for epitaxial growth of objects by chemical vapor

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Ojersjo, Sweden

Yujing Liu