A preformed coil of a rotor of a synchronous generator of a gearless wind power plant is provided. The preformed coil may be arranged around a pole shoe defining a central axis. The preformed coil has a plurality of windings and is made up of laminations.

In a method for producing a rotor for a synchronous machine suitable for a rotational speed of more than 1000 r.p.m, a plurality of electrically conductive rectangular sub-conductors are loosely joined in parallel to one another lengthwise to form a conductor. The conductor is wound so as to form a winding and thereby form an exciter coil. Directly after winding, the sub-conductors of the conductor are continuously soldered together while the sub-conductors are positioned and/or held together by a forming facility, so that the exciter coil is solid and the conductor rigid.

In a method for producing a rotor for a synchronous machine suitable for a rotational speed of more than 1000 r.p.m, a plurality of electrically conductive rectangular sub-conductors are loosely joined in parallel to one another lengthwise to form a conductor. The conductor is wound so as to form a winding and thereby form an exciter coil. Directly after winding, the sub-conductors of the conductor are continuously soldered together while the sub-conductors are positioned and/or held together by a forming facility, so that the exciter coil is solid and the conductor rigid.

A reluctance motor has: a stator provided with drive coils to which multiphase drive currents are inputted; and a rotor provided with a plurality of salient poles which receive primary rotating force when magnetic fluxes generated in the drive coils are interlinked with the rotor, and the rotor has: inductor pole coils which are placed on magnetic paths on which spatial harmonic components superimposed on the magnetic fluxes generated in the drive coils are interlinked with the rotor side so that induced currents can be generated in the inductor pole coils due to the spatial harmonic components of the magnetic fluxes; rectifier elements which rectify the induced currents generated in the inductor pole coils; and electromagnet coils as defined herein, and the inductor pole coils and the electromagnet coils do not serve for each other's purposes but are placed on the rotor individually.

An externally excited electric synchronous machine may include a machine rotor, a machine stator, and a signal transmission device for contactless transmission of an operating signal corresponding to a DC voltage to the machine stator. The machine rotor may include a rotor shaft and a machine rotor coil. The machine rotor coil may be supplied with DC voltage and may provide a magnetic rotor field. The machine stator may include a machine stator coil that is fixed relative to the machine stator. The machine stator coil may provide a magnetic stator field, which may interact with the magnetic rotor field such that the machine rotor rotates. The signal transmission device may include (i) on the machine rotor, a signal coil connected in series with the machine rotor coil and (ii) on the machine stator, a magnetic field sensor that detects a magnetic field provided via the signal coil.

An externally excited electric synchronous machine may include a machine rotor, a machine stator, and a signal transmission device for contactless transmission of an operating signal corresponding to a DC voltage to the machine stator. The machine rotor may include a rotor shaft and a machine rotor coil. The machine rotor coil may be supplied with DC voltage and may provide a magnetic rotor field. The machine stator may include a machine stator coil that is fixed relative to the machine stator. The machine stator coil may provide a magnetic stator field, which may interact with the magnetic rotor field such that the machine rotor rotates. The signal transmission device may include (i) on the machine rotor, a signal coil connected in series with the machine rotor coil and (ii) on the machine stator, a magnetic field sensor that detects a magnetic field provided via the signal coil.

An inductively electrically excited synchronous machine is disclosed. The synchronous machine includes a rotor including at least one rotor coil for generating a magnetic rotor field, a stator, on which the rotor is rotatably mounted about an axis of rotation, and including at least one stator coil for generating a magnetic stator field, and a rotary transformer for inductively transmitting electrical energy to the at least one rotor coil. The rotary transforming includes at least one stator-fixed transformer primary coil and at least one rotor-fixed transformer secondary coil. A machine controller is coupled to the stator coil and to the at transformer primary coil for operation as a motor and/or as a generator. A demagnetizing circuit is provided that includes at least one dynamo winding arranged on the stator. The demagnetizing circuit has at least one switching device for activating and deactivating the demagnetizing circuit.

An inductively electrically excited synchronous machine is disclosed. The synchronous machine includes a rotor including at least one rotor coil for generating a magnetic rotor field, a stator, on which the rotor is rotatably mounted about an axis of rotation, and including at least one stator coil for generating a magnetic stator field, and a rotary transformer for inductively transmitting electrical energy to the at least one rotor coil. The rotary transforming includes at least one stator-fixed transformer primary coil and at least one rotor-fixed transformer secondary coil. A machine controller is coupled to the stator coil and to the at transformer primary coil for operation as a motor and/or as a generator. A demagnetizing circuit is provided that includes at least one dynamo winding arranged on the stator. The demagnetizing circuit has at least one switching device for activating and deactivating the demagnetizing circuit.

An electric rotary transformer for inductive energy transmission is disclosed. The rotary transformer includes a rotary transformer stator including a transformer primary coil and a rotary transformer rotor, rotatable during operation relative to the rotary transformer stator about an axially running rotation axis, including a transformer secondary coil. The transformer secondary coil and the transformer primary coil interact inductively during operation for generating a transformer voltage in the transformer secondary coil. The transformer secondary coil and/or the transformer primary coil has at least one electric conductor, through which a flow path of a fluid is guided. During operation a fluid flows along the flow path and cools the rotary transformer.

Provided is a rotating electrical machine wherein it is possible to sufficiently cool an electronic device attached to a rotor by means of a liquid refrigerant. A rotor for a rotating electrical machine is provided with a shaft supported in a rotatable manner, a rotor core secured to the shaft, an electronic device disposed so as to rotate along with the shaft and the rotor core, a coil wound around the rotor core and connected to the electronic device, and a cooling structure for sequentially cooling the electronic device and the coil by means of a liquid refrigerant supplied from the shaft.