Singh, N.P(PhD)Hayato, Jemal2018-07-062023-11-282018-07-062023-11-282011-07http://etd.aau.edu.et/handle/12345678/7080Micro hydro power plants are stand alone renewable energy sources and free from emission of green house gases. It is an appropriate choice for rural electrification where supplying grid electricity is not economical. In Ethiopia, we have several irrigation dams, streams and running rivers which have considerable hydropower potential. Micro hydropower plants can be installed on the existing irrigation dam with less investment and time. Nowadays, electronic load controller is used to control the frequency of micro hydropower plants. However, electronic load controller wastes big amount of water during low power demand which can be diverted at high head for irrigation purposes. In addition, micro hydropower plants are characterized by parameter variations like damping constants where fixed control does not provide the desired performance under different operating conditions. Thus, development of an appropriate control scheme for micro hydropower seems inevitable to obtain the desired performance under different operating conditions. This thesis proposes fuzzy logic controller to tune the parameters of PI controller for frequency control of a micro hydropower plant and to supervise the energy dissipated on the ballast load. A detail dynamic model of micro hydropower plant is developed to design the proposed controller. Genetic algorithm is used to optimize the membership functions of the fuzzy logic controller. To meet a sudden consumer demand of power, 0.25p.u. power is dissipated on the ballast loads under steady state condition. It is observed from the simulation results that the average overshoot for 30% load change is 4.6% and the settling time is 7.5 seconds with the proposed fuzzy logic controller while overshoot is 8.9% and 13.5% and settling time is 11 seconds and 29 seconds with PI load control and PI flow control, respectively. Moreover, even for 70% load rejection, overshoot is only 11.6% and the settling time is 11 seconds. It is further observed that the change in energy wasted on ballast load from the desired value is always around zero at steady state conditions. Key Words: Micro Hydropower, Irrigation Dams, PI Controller, Fuzzy Logic Controller, Genetic Algorithm Chapter OneenMicro HydropowerIrrigation DamsPi ControllerFuzzy Logic ControllerGenetic AlgorithmThesis