Hydrogenerators

Ansaldo Energia has produced more than 500 hydrogenerators since 1920, and many of them are still in operation – further proof of their reliability.
Hydrogenerators can have an extremely wide rotational speed range (between 50 and 1,200 rpm) depending on site condition. This impacts on the configuration of shaft and bearings, and on the diameter and structure of the rotor: all factors that are determined based on location and specific needs.
Ansaldo Energia currently produces three basic types of hydrogenerators (all can also operate as Synchronous Condenser):

• generators for river flow (low/medium speed);
• generators for high-head plants (medium/high speed);
• motor-generators for pumped storage systems.

They are self-ventilated in open or closed circuit. Air-to-water coolers are equipped with indirectly-cooled stator and rotor winding. The stator winding can be of the lap or wave type, with closed coils or two half-coils. Depending on the generator configuration, the rotor is supported with guide bearings, thrust bearings, combined thrust-guide bearings or pedestal bearings in horizontal arrangement. 
Braking system and high-pressure jacking equipment are supplied to achieve rapid, safe shutdown and to allow rotor lifting during maintenance.