Siemens Aktiengesellschaft

Olaf Michelsson

Marcus Banda

Martin Hiller

Zhiyun Chen

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 device for increasing fault clearing time is provided having a component part designed to identify a short circuit event and load resistors connectable in the event of a fault such that the turbine power transmitted to the shaft is electrically absorbed by the generator and converted into heat until the grid comes back online.

Growing community of inventors

Arnstadt, Germany

Olaf Michelsson