ABSTRACT
Francis turbines with spiral case, horizontally arranged, operated under the heads from 10 up to 120 m and for outputs up to 5000 kW. In case of larger units the vertical arrangement can be used. These turbines have high efficiencies however they can operate at lower discharge capacity range in comparison with Kaplan units. Control equipment involving speed governing system delivered to the turbine units is usually based on programmable module SAIA. Majority of customers demands the small turbine units for parallel operation into common public grid. Asynchronous generators are simple electric squirrel-cage induction motors, with no possibility of voltage regulation, which operate at a speed directly related to system frequency. The block system allows modifying governor according to the client s demands. This system can be designed either for complete power station control or for governing turbine speed only.
