Siemens Aktiengesellschaft

Marcus Banda

Olaf Michelsson

Roland Röding

Haiko Adolf

Martin Hiller

Zhiyun Chen

Norbert Keyssner

Lothar Trefflich

A regulating device for a brushless excitation system for supplying at least one excitation coil of a rotor of a synchronous machine with excitation current, having a detection device to detect a strength of a magnetic flux; a regulating unit to generate an auxiliary excitation DC current supplied to the main excitation machine by rectifying an auxiliary excitation three-phase current, and to regulate the current strength of the auxiliary excitation DC current such that a magnetic flux generated between the rotor and the stator of the main excitation machine is kept constant independently of the current strength of the excitation current; and an adjusting unit rotationally fixed to a rotor shaft of the synchronous machine to generate the excitation current by rectifying an excitation three-phase voltage generated by the main excitation machine and to regulate the current strength of the excitation current supplied to the rotor of the synchronous machine.

Supplying a synchronous machine with an excitation current

A cooling device for cooling an air-permeable winding braid of an electrical machine is provided. The cooling device includes a baffle and a fan, which is arranged for blowing a stream of cooling air substantially perpendicularly onto a first surface portion of one side of the wind braid, wherein, in the region of a second surface portion of the side of the winding braid, arranged alongside the first surface portion, the baffle is arranged substantially parallel to and that a distance from the surface of the second surface portion such that a partial stream of the stream of cooling air is formed in the channel that is formed by the baffle and the second surface portion, and so, on the side of the winding braid that is opposite from the first-mentioned side, the other partial stream of the stream of cooling air, penetrating the winding braid, flows away from the winding braid without any return flow.

Cooling device for cooling a winding braid of an electrical machine and method for retrofitting the electrical machine with the cooling device

A method for determining a temperature at a predetermined location in a winding of subconductors of an electric machine is provided where each subconductor is encased in electric subconductor insulation. The method includes predetermining the location between one of the subconductors and the associated subconductor insulation; arranging, in said winding, an optical fiber with a sensor material piece that is fixed to the predetermined location, the optical properties of said sensor material piece being temperature-dependent and uninfluenced by stretching; exposing the sensor material piece to light via the optical fiber such that, following an interaction with the sensor material piece, light is emitted from said sensor material piece; measuring the spectrum of the light; and using this spectrum to determine the temperature at the predetermined location.

Method for determining a temperature in a winding of subconductors of an electric machine

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Erfurt, Germany

Marcus Banda