Abstract
This paper considers the design of a high efficiency small-size generator for micro-hydroelectric energy production. Different generator designs are compared in order to identify the best solution to be adopted in such installations. Due to the small power rating, the same generator is considered in different installations, with different net heads and water flow. This allows to improve the cost-effectiveness of the system. This is achieved operating the generator at different frequencies in various conditions, being the grid connection achieved by means of an inverter. Therefore, the performance of the designed generators are evaluated considering also operations at different speed.