Design of a PM-generator for a straight flow counter-rotating micro-hydro turbine

This paper presents the design and the measurement of two identical PM-generators driven by an axial counter-rotating micro-turbine, called DuoTurbo-microturbine. This prototype for drinking water networks has been jointly developed by the HES-SO Valais//Wallis, the EPFL-Laboratory for Hydraulic Machines and industrial partners. The modular in-line “plug & play” technology requires low investment, reaching economic feasibility with an available power between 5 kW and 25 kW. One stage of the microturbine consists of two axial counter-rotating runners that form a compact independent unit. Each runner of the turbine holds its own rim generator, the DuoTurbo-configuration involving that each hydraulic runner is integral with each electrical rotor [1].