Source : Webster's Revised Unabridged Dictionary (1913)

Turbogenerator \Tur`bo*gen"er*a`tor\, n. [See {Turbine}, and
   {Generator}.]
   An electric generator or dynamo which is combined on one
   frame with a turbomotor, by which it is driven.

Source : WordNet®

turbogenerator
     n : generator consisting of a steam turbine coupled to an
         electric generator for the production of electric power