Possibilities to increase power and efficiency of hydro generating unit

Abstract

Within the scope of preparation and planning the revitalization, efforts are made in order to increase the output power and efficiency of generator and turbine. Thereby, it is necessary to carry on analysis of possible power increase of the whole unit without changing its physical dimensions. Possibilities to increase power one may find at the fact those previous series of generators were designed and built from materials, comparing to nowadays materials, with modest dialectical, magnetic and thermal characteristics. By using modern materials to replace active generator's parts, a revitalized generator becomes oversized for former power rating. On a turbines, as well, during the replacement of worn-off active mechanism and parts (of counter flow assembly), a possibility usually arise to, with minor applicable changes, increase flow and/or efficiency without changing physical dimensions. Alongside of efforts to rebuild unit with increased power, a trial to run the old unit on a higher power ratio even before revitalization has been made. Within analysis of possibilities to increase output power, no matter if power increase is before or after revitalization, it is necessary to: recalculate electromagnetic values and parameters of the generator, its thermal conditions for its designed rated mode and also for 5% to 20% overload; verify the calculated data experimentally, considering the temperature rises and the vibration conditions of unit during tests for most important data; confirm the possibility of the turbine to deliver adequate power to the generator. In this paper the methodology of analyzing the power increase possibilities, as some of the results that were achieved over the last few years, has been presented.