Passive-rotor disk-shaped transverse-flux permanent-magnet generator for small wind turbine application

A disk-shaped transverse-flux permanent-magnet generator with passive-rotor is investigated in this paper. The main advantage of this structure is its modular bulk iron made rotor core while coil and permanent-magnets are placed on stator that results in more reliable and rigid machine. Configuration and principles of the proposed structure are introduced and a typical machine is simulated by a 3D-finite element tool. The parametric analysis on two main geometrical parameters of the machine structure is performed. The optimization goal is reducing the cogging torque while keeping the induced no-load voltage almost constant. Finally, performance characteristics for the optimal design are presented.