Hydro turbine driven generators have a running speed in the range of
187rpm to 1800rpm. In case of hydro turbine generators, the performance
requirements will be unique depending on the type of hydro turbine, grid
and power house conditions. Generally, these machines are located in
remote places where accessibility is very poor and due to such
conditions, there is a requirement for high reliability. Further, in
case of weak grid conditions, they would require generators to be
specially designed for high inertia requirements to absorb frequent
tripping and should further have a rugged design to transfer all the
forces to foundation smoothly. The rotor assembly requires specialized
design, assembly and balance to operate at high runaway speeds.The
generators are designed and manufactured for various types of hydro
turbines, such as Kaplan turbines, Francis turbines and Pelton turbines.
Each of these three turbines has different design requirements with
respect to the generators.