Abstract: In a plant containing a turbo-generator the magnetic circuit of the turbo-generator is included in an electric generator which directly supplies a high supply voltage of 20-800 kV, preferably higher than 36 kV. The insulation of the generator is built up of a cable (6) comprising one or more current-carrying conductors (31) with a number of strands (36) surrounded by outer and inner semiconducting layers (34, 32) and intermediate insulating layers (33). The outer semiconducting layer (34) is at earth potential. The phases of the winding are Y-connected. The Y-point may be insulated and protected from over-voltage by means of surge arresters, or else the Y-point may be earthed via a suppression filter.

Abstract: The magnetic circuit of a generator in a hydro-generator plant is arranged to directly supply a high supply voltage of 20-800 kV, preferably higher than 36 kV. The generator is provided with solid insulation and its winding includes a cable (6) comprising one or more current-carrying conductors (31) with a number of strands (36) surrounded by at least one outer and one inner semiconducting layer (34, 32) and intermediate insulating layers (33). The outer semiconducting layer (34) is at earth potential. The stator winding may be produced with full or fractional slot winding, the phases of the winding being Y-connected. The Y-point may be insulated and protected from over-voltage by means of surge arresters, or else the Y-point may be earthed via a suppression filter. The invention also relates to a hydro-generator plant, a generator included in the plant and a procedure for building such a plant.

Abstract: For a method of operating of a synchronous compensator including a rotating electric machine including a rotor and a stator with at least one winding with a solid insulation enclosing the electric field, relevant parameters for temperature conditions in the rotor are determined, and during over-excited operation, to temporarily enlarge the field of operation of the synchronous compensator, cooling of the rotor is forced depending on a rotor temperature value determined from the parameters. The synchronous compensator measures parameters relevant for the temperature conditions of the rotor. A mechanism is also provided to force the cooling of the rotor depending on rotor temperature values determined from the parameters during over-excited operation of the electric machine.