PM Wind Generator with Reduced Amount of Rare-Earth Magnet Material

This paper presents a new rotor for permanent magnet wind generators aimed to reduce the amount of rare-earth materials. The new rotor configuration has been used for the design of a 10 MW PM generator for direct drive wind turbines in order to reduce their magnet costs. In order to prove its effectiveness, also a conventional PMSG with surface magnets rotor is considered as reference machine for comparison. Using the same geometry and electrical constrains the both PMSGs are developed following an analytical iterative procedure and afterwards using FEA. According to the preliminary results, the new rotor design requires significantly less magnet material compared with the conventional rotor. Investigations done on the 10 MW PMSG shows that with the proposed design the magnet weight can be reduced for about 2.7 tons.