Design of a Direct Drive Permanent Magnet Vernier Generator for a Wind Turbine System

In this study, a novel method for design of a direct drive(DD) PM vernier generator (PMVG) is proposed for a gearless, high power and lightweight wind turbine system. In the proposed design method, the base and maximum speeds of the generator are firstly obtained from the nature of aerodynamic power, and then the electrical circuit parameters of the generator are scoped with consideration of the control strategy of PM machines. To determine the generator geometries using the scoped parameters, the relational equations between the parameters and geometries of a PMVG with concentrated windings are derived. A systematic method for design using the derived equations and the parameters is developed, and the 5kW PMVG with outer rotor is designed through the proposed method. The performance characteristics of the designed generator are analyzed with FE simulations and compared with analytically predicted results.