Effect of PM parameters variability on the operation quantities of a wind generator

Permanent magnet machines magnetic losses and output characteristics are directly related to the permanent magnet material characteristics. In this paper we study the effect of variability in these characteristics on the operation quantities of a low speed permanent magnet wind generator. The variability itself can emerge as the result of misuse of the generator or as the consequences of the manufacturing process, which makes the characteristics different from the nominal ones. The investigations are carried out with transient finite element analysis. The results show that the most affected quantities are the power factor and the copper losses. The iron losses are slightly affected too. All these effects are shown to be the consequence of the change in the air gap flux density, which is one of the most important design parameter of the machine.