Efficiency optimization of small hydro power plant in low power operation

This paper deals with a low power operation of small hydro power plants. It is typical for small hydro power plants on small rivers without reservoirs where the power in low season is less than one-third of nominal power. That is why the efficiency is decreased. The generator has low efficiency in this operation due to constant no load losses. The analysis of losses is presented and possible improvements are suggested. The last part of this paper presents a simple method of reducing no load losses, calculation of the power savings and experimental validation of this method.