Variable speed generator with constant voltage and frequency esp. for wind-power applications, comprises rotor enclosed within stator, itself rotatable on shaft concentrically enclosing rotor's

摘要

The rotor shaft (2) is driven, eg. by wind turbine, through an endpulley (3). This end runs in a bearing in the machine's fixed frame (24). At the other end, the rotor field winding (9) is connected (8), through a central passage (6) in a shaft extension (4), to sliprings (10) with brushgear completing the external circuit (25). The extension runs in a bearing (15) set centrlaly in the end-bell (13) of the stator (12), itself supported on a bearing (23) in the frame, while at the driven end a bearing on the rotor shaft supports the stator. The end-bell is integral with a hollow shaft (14,20) which encloses the rotor shaft extension up to the sliprings. The annular space between these shafts (16) accommodates the stator winding connections (17); these end on a second set of sliprings (19) with associated brushgear (26). A cooling fan (27) is located on the rotor shaft at the driven end. The stator's rotational freedom is controlled by an eg. electromagnetic powder coupling (22) to the fixed frame at the end-bell support bearing (23). This can be energized or deenergized by an electronic controller to maintain a constant speed differential between rotor and stator over a selected range of turbine speed variation. Two variants are described.