Abstract: A controller, a wind turbine and a method of operating an electrical synchronous machine, includes a rotor and a stator having a first winding set, the method including: using a first position observer configured to observe the first winding set in order to observe a first value of the rotor position; synchronizing the machine based on the first observed value or an external initial value of the rotor position.

Abstract: Provided is an arrangement for producing electric energy, including: a generator having plural winding sets; plural converters each connected to one of the winding sets; at least two transformers, each connected at a low voltage side to output terminal of at least one converter; and a control portion connected to control the converters.

Abstract: Provided is a method of controlling a converter, in particular of a wind turbine, the converter including a first converter portion connected to a generator, a DC-link, and a second converter portion connected to a utility grid. The method including: controlling the first converter portion and the second converter portion by a first control signal and a second control signal, respectively, both being derived based on a requested power signal, in particular requested active power signal, and a generator rotational speed, wherein the first control signal indicates substantially constant generator torque for rotational speed variations of the generator rotational speed above a frequency threshold.

Abstract: A spool-less system for deployment, recovery and manipulation of a traversable road covering track. The system includes an arcuate guide member detachably coupled to a retaining member; the guide member and retaining member defining a volume for receiving a roll of traversable road covering; the guide member arranged to contact the roll along a first arcuate range and the retaining member configured to contact the roll along a second arcuate range; and wherein the guide member and retaining member are detachably coupleable having, a first position in which, the guide member and retaining member are separated at a first diameter whereby the roll of traversable road covering may be deployed or recovered when the host machine is in motion, and a second position in which, the guide member and retaining member are separated at a second diameter in which the roll of traversable road covering is retained.

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 an arrangement for producing electric energy, including: a generator having plural winding sets; plural converters each connected to one of the winding sets; at least two transformers, each connected at a low voltage side to output terminal of at least one converter; and a control portion connected to control the converters.

Abstract: A spool-less system for deployment, recovery and manipulation of a traversable road covering track is provided. The system includes an arcuate guide member detachably coupled to a retaining means; the guide member and retaining means defining a volume for receiving a roll of traversable road covering; the guide member arranged to contact the roll along a first arcuate range and the retaining means configured to contact the roll along a second arcuate range; and wherein the guide member and retaining means are detachably coupleable having, a first position in which, the guide member and retaining means are separated at a first diameter whereby the roll of traversable road covering may be deployed or recovered when the host machine is in motion, and a second position in which, the guide member and retaining means are separated at a second diameter in which the roll of traversable road covering is retained.

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: A method of controlling a power unit having a plurality of converter modules coupled in parallel, is configured to convert DC into AC voltages or AC into DC voltage. The method includes (a) receiving a control value for each phase of each converter module, (b) obtaining a set of phase current values for each converter module, (c) generating a compensation value for each phase of each converter module based on the set of phase current values and a set of stored data, the set of data representative of non-linearity characteristics of the converter modules as functions of phase current value, (d) generating a compensated control value for each phase of each converter module based on the corresponding control value and compensation value, and (e) supplying the compensated control values to the respective converter modules. A controller, power unit, wind turbine, computer program and computer program product are similarly configured.

Abstract: A method of controlling a power unit having a plurality of converter modules coupled in parallel, is configured to convert DC into AC voltages or AC into DC voltage. The method includes (a) receiving a control value for each phase of each converter module, (b) obtaining a set of phase current values for each converter module, (c) generating a compensation value for each phase of each converter module based on the set of phase current values and a set of stored data, the set of data representative of non-linearity characteristics of the converter modules as functions of phase current value, (d) generating a compensated control value for each phase of each converter module based on the corresponding control value and compensation value, and (e) supplying the compensated control values to the respective converter modules. A controller, power unit, wind turbine, computer program and computer program product are similarly configured.

Abstract: A method of operating an inverter for converting a DC power into AC power by use of a pulse width modulation switching scheme is provided is disclosed. The inverter is controlled by use of the pulse width modulation switching scheme to provide an alternating current based on a current demand signal defining an alternating current provided by the inverter. An upper current threshold and a lower current threshold are provided. An instantaneous value of the alternating current is measured. When the instantaneous value of the alternating current overshoots the upper current threshold or undershoots the lower current threshold, the pulse width modulation switching scheme is replaced by an amended switching scheme which controls the instantaneous value of the alternating current to be between the upper current threshold and the lower current threshold. The upper current threshold and the lower current threshold oscillate with at least one alternating phase.

Abstract: A controller device for controlling a power converter device of an electrical generator during rotation of the electrical generator includes a signal converter which is configured to receive an angle signal and in response hereto transposes a current feedback onto two axes of a rotating d, q-reference frame. Further, a current controller has a regulator receiving a d-axis feedback and a d-axis demand and provides in response hereto a d-axis response operative in reducing the difference between the d-axis feedback and the d-axis demand. An error unit provides an error signal indicative of an angle error of the rotating reference frame on the basis of the d-axis response of the d-axis regulator.

Abstract: A controller device for controlling a power converter device of an electrical generator during rotation of the electrical generator includes a signal converter which is configured to receive an angle signal and in response hereto transposes a current feedback onto two axes of a rotating d, q-reference frame. Further, a current controller has a regulator receiving a d-axis feedback and a d-axis demand and provides in response hereto a d-axis response operative in reducing the difference between the d-axis feedback and the d-axis demand. An error unit provides an error signal indicative of an angle error of the rotating reference frame on the basis of the d-axis response of the d-axis regulator.

Abstract: A method of operating an inverter for converting a DC power into AC power by use of a pulse width modulation switching scheme is provided is disclosed. The inverter is controlled by use of the pulse width modulation switching scheme to provide an alternating current based on a current demand signal defining an alternating current provided by the inverter. An upper current threshold and a lower current threshold are provided. An instantaneous value of the alternating current is measured. When the instantaneous value of the alternating current overshoots the upper current threshold or undershoots the lower current threshold, the pulse width modulation switching scheme is replaced by an amended switching scheme which controls the instantaneous value of the alternating current to be between the upper current threshold and the lower current threshold. The upper current threshold and the lower current threshold oscillate with at least one alternating phase.