Abstract: Provided is a method of controlling a multi-channel multi-phase electrical machine including a plurality of channels each with a set of phase windings connected to a converter, which method includes the steps of operating the converters to electrically phase-shift the channels; computing harmonic injection currents for a dominant harmonic on the basis of electrical quantities in a rotating reference frame; determining harmonic voltage references for the dominant harmonic on the basis of the harmonic injection currents; and regulating the AC output voltages of the channels according to the fundamental voltage references and the harmonic voltage references. Also provided is a control arrangement of a multi-channel multi-phase electrical machine; a wind turbine; and a computer program product.

Abstract: Provided is a stator assembly including: i) a first stator segment, ii) a second stator segment, wherein the first stator segment and the second stator segment being arranged along a circumferential direction of the stator assembly, and wherein the first stator segment and the second stator segment are located adjacent to each other and are separated by a gap. The stator assembly further including: iii) at least one first coil set of a first multi-phase coil system, and iv) at least one second coil set of a second multi-phase coil system, wherein each coil set includes at least one coil for each phase of the respective multi-phase coil system. Each stator segment includes a first busbar arrangement having first busbar elements, and a second busbar arrangement having second busbar elements, each busbar element being assigned to one phase.

Abstract: Provided is an arrangement for an electrical machine having fractional slot topology, including: plural stator segments, each stator segment having plural teeth alternating with plural slots in a circumferential direction, each stator segment having at both circumferential ends a tooth portion; for each phase of plural phases a conductor wound in coils around teeth of the plural teeth, wherein the number of coils of any phase in any stator segment is the same as the number of coils of any other phase in this stator segment.

Abstract: Provided is a stator assembly including: i) a first stator segment, ii) a second stator segment, wherein the first stator segment and the second stator segment being arranged along a circumferential direction of the stator assembly, and wherein the first stator segment and the second stator segment are located adjacent to each other and are separated by a gap. The stator assembly further including: iii) at least one first coil set of a first multi-phase coil system, and iv) at least one second coil set of a second multi-phase coil system, wherein each coil set includes at least one coil for each phase of the respective multi-phase coil system. Each stator segment includes a first busbar arrangement having first busbar elements, and a second busbar arrangement having second busbar elements, each busbar element being assigned to one phase.

Abstract: Provided is a method and arrangement for controlling a multi winding set permanent magnet electrical machine in case of a fault in a first group of the winding sets leaving a second group of the winding sets functional, the method comprising: determining a value of a torque generated by all winding sets; and controlling values of currents of the second group of winding sets based on the value of a torque, in order to reduce a damaging torque and/or a torque oscillation occurring and/or to break the machine.

Abstract: A generator armature including a plurality of laminate sheets stacked to form an annular arrangement of armature teeth, whereby each pair of adjacent armature teeth is separated by an axial winding slot extending a direction essentially parallel to an axis of rotation of the generator; and a plurality of radial cooling channels, whereby a radial cooling channel is realized to transport a cooling medium and extends from an axial winding slot to an interior cavity of the generator, and wherein a radial cooling channel includes a series of aligned notches in the laminate sheets of a laminate stack is provided. A laminate sheet for an armature of a generator, a cooling arrangement, a generator, a wind turbine, and a method of cooling stator windings arranged on an armature of a generator is also provided.

Abstract: A device for limiting a fault current for a generator, in particular of a wind turbine is provided. A first frame is made of a ferromagnetic material, wherein the first frame comprises a first frame section and a further first frame section, wherein a first gap is formed between the first frame section and the further first frame section. A first coil is wound around the first frame section, wherein the first coil is connectable to a first stator winding of a stator of the generator. A further first coil is wound around the further first frame section, wherein the further first coil is connectable to an electronic device. A first permanent magnet element is arranged inside the first gap. The first frame section and the further first frame section are formed with respect to each other such that an electromagnetic interaction between the first coil and the first permanent magnet element and the further first coil and the first permanent magnet element is provided.

Abstract: An electric generator arrangement with a stator being equipped with at least two opposed phase windings, each winding comprising at least two sub-windings in series is provided. The arrangement also comprises a controlled varistor across the connections of the sub-windings of said opposed phase windings. A current imbalance between two opposed phase windings is measured and the varistor is controlled in such a way that the resistance of the varistor is increased when the current imbalance increases.

Abstract: A device for connecting an electric power generator to an HVDC transmission system is provided, the device having (a) a first unit for converting an AC output voltage from the electric power generator to a DC input voltage for the HVDC transmission system, the first unit having a transformer and a full-bridge rectifier, and (b) a second unit for generating control voltages and/or control currents in the transformer and/or in the electric power generator, the second unit having a PWM full-bridge converter adapted to receive the AC output voltage from the electric power generator or an AC voltage based on said AC output voltage. Furthermore, a system and a method are provided.

Abstract: A generator for producing electric power, the generator including a generator unit including a stator) and a rotatably supported rotor, wherein the stator includes a first set of windings and a second set of windings, and the rotor is adapted to induce electrical voltage in the first set of windings and in the second set of windings when the rotor is rotated relative to the stator, the generator further includes a first converter coupled to the first set of windings, the first converter being adapted to convert alternating voltage in the first set of windings into an output DC voltage, a DC output coupled to the first converter to receive the output DC voltage, and a second converter coupled to the second set of windings and to the DC output, the second converter being adapted to generate control voltages and/or control currents in the second set of windings, is provided.

Abstract: A generator armature including a plurality of laminate sheets stacked to form an annular arrangement of armature teeth, whereby each pair of adjacent armature teeth is separated by an axial winding slot extending a direction essentially parallel to an axis of rotation of the generator; and a plurality of radial cooling channels, whereby a radial cooling channel is realized to transport a cooling medium and extends from an axial winding slot to an interior cavity of the generator, and wherein a radial cooling channel includes a series of aligned notches in the laminate sheets of a laminate stack is provided. A laminate sheet for an armature of a generator, a cooling arrangement, a generator, a wind turbine, and a method of cooling stator windings arranged on an armature of a generator is also provided.

Abstract: A cooling arrangement configured to cool stator windings of the stator of a generator, the cooling arrangement including an inflow guiding means for guiding a cooling airflow into axial winding channels, wherein an axial winding channel extends along a gap between adjacent stator windings in a direction essentially parallel to an axis of rotation of the generator, and subsequently into an interior cavity of the stator, and an outflow guiding means for removing the cooling airflow from the interior cavity of the stator is provided. A generator including an outer rotor and an inner stator, the stator including an arrangement of stator teeth about an annular supporting structure and a plurality of windings arranged pair-wise between adjacent stator teeth, and wherein the stator is configured for connection to a cooling arrangement is also provided. A wind turbine and a method is further provided.

Abstract: A device for connecting an electric power generator to an HVDC transmission system is provided, the device having (a) a first unit for converting an AC output voltage from the electric power generator to a DC input voltage for the HVDC transmission system, the first unit having a transformer and a full-bridge rectifier, and (b) a second unit for generating control voltages and/or control currents in the transformer and/or in the electric power generator, the second unit having a PWM full-bridge converter adapted to receive the AC output voltage from the electric power generator or an AC voltage based on said AC output voltage. Furthermore, a system and a method are provided.

Abstract: A generator for producing electric power, the generator including a generator unit including a stator) and a rotatably supported rotor, wherein the stator includes a first set of windings and a second set of windings, and the rotor is adapted to induce electrical voltage in the first set of windings and in the second set of windings when the rotor is rotated relative to the stator, the generator further includes a first converter coupled to the first set of windings, the first converter being adapted to convert alternating voltage in the first set of windings into an output DC voltage, a DC output coupled to the first converter to receive the output DC voltage, and a second converter coupled to the second set of windings and to the DC output, the second converter being adapted to generate control voltages and/or control currents in the second set of windings, is provided.

Abstract: A device for limiting a fault current for a generator, in particular of a wind turbine is provided. A first frame is made of a ferromagnetic material, wherein the first frame comprises a first frame section and a further first frame section, wherein a first gap is formed between the first frame section and the further first frame section. A first coil is wound around the first frame section, wherein the first coil is connectable to a first stator winding of a stator of the generator. A further first coil is wound around the further first frame section, wherein the further first coil is connectable to an electronic device. A first permanent magnet element is arranged inside the first gap. The first frame section and the further first frame section are formed with respect to each other such that an electromagnetic interaction between the first coil and the first permanent magnet element and the further first coil and the first permanent magnet element is provided.

Abstract: An electric generator arrangement with a stator being equipped with at least two opposed phase windings, each winding comprising at least two sub-windings in series is provided. The arrangement also comprises a controlled varistor across the connections of the sub-windings of said opposed phase windings. A current imbalance between two opposed phase windings is measured and the varistor is controlled in such a way that the resistance of the varistor is increased when the current imbalance increases.

Abstract: A rotor magnet engagement assembly includes a rotor base plate, a first magnetic interpole element, and a second magnetic interpole element. The first magnetic interpole element and the second magnetic interpole element are attached to the rotor base plate in such a manner that a gap is provided between the first magnetic interpole element and the second magnetic interpole element. The first magnetic interpole element, the second magnetic interpole element, and the rotor base plate form a recess, wherein the recess is adapted to receive a magnet in such a manner that the magnet is fixed to the rotor base plate. It is further described a method for manufacturing a rotor magnet engagement assembly, a rotor magnet arrangement, a rotor for an electromechanical transducer, and an electromechanical transducer.

Abstract: A flux-switching machine stator comprising two or more C-cores, each C-core having two legs and a back portion joining the legs, and a permanent magnet arranged between legs of adjacent C-cores. Each leg has a main portion and a tip portion further from the back portion characterized in that the tip portion of each leg is angled relative to the main portion of the respective leg.

Abstract: An electrical machine including a permanent magnet and a coil is provided. The coil is arranged to interact with the permanent magnet via an air gap, which located between the two. Electrical power is generated in the coil when the permanent magnet or the coil is moved in their relative position to each other. The permanent magnet includes a surface, which is aligned to the coil and to the air gap so that that magnetic forces of the permanent magnet interact via the surface and the air gap with the coil by a magnetic flux density distribution. The permanent magnet also includes a base plane and a transition area. A first side of the surface is connected with the adjacent base plane via the transition area. The cross-section of the transition between the surface and the adjacent base plane is determined by a Bezier function.

Abstract: An electrical machine including a permanent magnet and a coil is provided. The coil is arranged to interact with the permanent magnet via an air gap, which located between the two. Electrical power is generated in the coil when the permanent magnet or the coil is moved in their relative position to each other. The permanent magnet includes a surface, which is aligned to the coil and to the air gap so that that magnetic forces of the permanent magnet interact via the surface and the air gap with the coil by a magnetic flux density distribution. The permanent magnet also includes a base plane and a transition area. A first side of the surface is connected with the adjacent base plane via the transition area. The cross-section of the transition between the surface and the adjacent base plane is determined by a Bezier function.