Full efficiency of energy conversion in small hydropower plants (SHP) can be achieved for power technology with generators working at a variable speed. This paper presents a concept of a energy conversion system dedicated for application in a prototype SHP which is based on a permanent magnet (PM) generators with a propeller turbine integrated with the generator rotors. These PM generators can work at a variable speed and therefore energy produced by the PM generators have to be converted by means of a power electronic unit to fit to the three-phase power grid parameters. The elements of such SHP like PM generator and power electronic unit are described in details.

Full efficiency of energy conversion in small hydropower plants (SHP) can be achieved for power technology with generators working at a variable speed. This paper presents a concept of a energy conversion system dedicated for application in a prototype SHP which is based on a permanent magnet (PM) generators with a propeller turbine integrated with the generator rotors. These PM generators can work at a variable speed and therefore energy produced by the PM generators have to be converted by means of a power electronic unit to fit to the three-phase power grid parameters. The elements of such SHP like PM generator and power electronic unit are described in details.