Comparison of air-cored and iron-cored non-overlap winding radial flux permanent magnet direct drive wind generators

In this paper a comparative study of the air-cored and iron-cored direct-drive permanent magnet wind generators is done. The comparative study is based on optimum designed air- and iron-cored wind generators on a 15 kW power level. With the generators designed to have the same power and efficiency performances, mainly mass difference is compared, but other aspects such as performance quality, per unit impedance and magnet demagnetisation, amongst other things, are also compared. Although a high amount of permanent magnet material is used in the air-cored generator, this generator is shown to have very attractive features for converter-fed direct-drive wind generator applications.