High performance direct driven hydroelectric generators for mini-micro power stations

Mini-Micro hydro power plants are widely used as they represent the best tradeoff among energy requirements, limited environmental-social impact, high system efficiency and reduced investments. The hydro generators are an essential part of the system and their performances effect the overall power plant quality goals. The direct-drive configuration (turbine and generator running at the same mechanical speed) will increase the system efficiency, save space in the hydro station, reduce maintenance, preserve the environment by limiting the lubricant usage in the power station. Adequate mechanical arrangements are necessary to match speed/stress constraints as well as electric/high efficiency performance requirements. In the paper a description on the possible solutions for mini hydroelectric generators is proposed.