Traditional hydropower plant revamping based on a variable-speed surface permanent-magnet high-torque-density generator

In today´s energy-saving and optimization programs, hydroelectric power plays a key role as it is based on a clean renewable energy source and capable of fulfilling a significant portion of the overall power demand. However, many hydropower plants have been in service for decades and are built with obsolete technology. In order to better exploit their potentialities, they often need large renewal or revamping actions. This paper offers an example showing how a traditional 600-kW run-of-river hydropower plant performance and layout can be enhanced by replacing fixed-speed induction generators with variable-speed permanent-magnet generators suitable for direct coupling with the hydraulic turbine and connected to the grid through an AC/AC power converter.