Permanent magnet technology in wind power generators

Permanent magnet technology offers a large variety of different machine design concepts. Neodymium Iron Boron magnets dominate the market. The magnet properties and prices are nowadays acceptable but the designer must understand how to select and utilize safely the magnet materials. The use of permanent magnet generators (PMGs) is gaining popularity also in wind power generation. In practice, there are three PM wind generator alternatives: 1) direct-drive (DD) generators (10 - 20 min^-1), 2) medium-speed (MS) generators (100 - 300 min^-1) and 3) high-speed (HS) generators (1000 - 2000 min^-1).