Abb Schweiz Ag

Mehanathan Pathmanathan

Ghanshyam Shrestha

Pedro Rodriguez

Chenjie Lin

Tuomas Janhunen

Sjoerd Bosga

Yujing Liu

Luca Peretti

Subrat Sahoo

Omer Ikram Ul Haq

Jan Mikael Westerlund

Robert Chin

Eino Silander

Veli-Matti Leppänen

Veli-Matti Leppanen

Pasi Paloheimo

Susanna Bäckström-Andersson

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

Unique systems, methods, techniques and apparatuses of exciterless synchronous machines are disclosed. One exemplary embodiment is a fractional slot synchronous machine comprising a rotor including a first pole pair including a first pole including a first plurality of slots having a first center point and arranged on a first outer surface in a slot pattern; a second pole pair including a second pole including a second plurality of slots having a second center point and arranged on a second outer surface in the slot pattern; energy harvest windings arranged in a winding pattern within a portion of the first plurality of slots and arranged in the same winding pattern within a portion of the second plurality of slots, the energy harvest winding being structured to receive a harmonic power from the stator; and a rectifier structured to receive the harmonic power from the energy harvest winding.

Rotor with asymmetric energy harvest windings

Unique systems, methods, techniques and apparatuses of an exciterless synchronous generator are disclosed. One exemplary embodiment is an exciterless synchronous generator comprising a stator, a rotor, and a startup excitation system. The stator includes a set of stator windings. The rotor includes an energy harvest winding, a DC power supply including a DC bus and coupled to the energy harvest winding, and a field winding coupled to the DC power supply. The startup excitation system comprises one of a magnetic field generation system structured to generate a magnetic field received by the energy harvest winding in response to a rotation of the rotor, wherein the magnetic field is converted to DC power with the DC power supply and transmitted to the field winding; or a rotor DC power source including and diode coupled in series across the DC bus.

Apparatuses, methods, and systems for starting an exciterless synchronous generator

Unique systems, methods, techniques and apparatuses of a rotating DC power supply are disclosed. One exemplary embodiment includes a first and second DC bus rail, a first and second leg, and a discharge resistor. The first leg includes a first semiconductor device and a second semiconductor device coupled in series at a first midpoint connection, the first semiconductor device being coupled to a first point on the first DC bus rail and the first midpoint connection being coupled to a field winding. The second leg includes a third semiconductor device and a fourth semiconductor device coupled in series at a second midpoint connection, the third semiconductor device being coupled to a second point on the first DC bus rail and the second midpoint connection being coupled to the field winding. The discharge resistor is operatively coupled to the first DC bus rail between the first point and the second point.

Rotating direct current power supply for synchronous machines

A method for determining an undesired condition in an electrical drive system including an electrical machine and an electrical drive, wherein the method includes a) obtaining a measured signal of an electrical or mechanical parameter, b) obtaining a frequency spectrum of the measured signal, that contains a measured frequency component, c) determining whether the measured frequency component is within a predetermined distance from a trend line, which trend line is associated with only one specific frequency component of the electrical or mechanical parameter present during a specific undesired condition, d) on the condition that the measured frequency component is within the predetermined distance from the trend line increasing a counter associated with the trend line, e) repeating steps a) to d), wherein in case the counter reaches a predetermined number determining that the electrical drive system is subjected to the undesired condition associated with the trend line.

Method and controller for determining an undesired condition in an electrical drive system

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Västerås, Sweden

Mehanathan Pathmanathan