Design and simulation of a coreless axial flux synchronous generator

Axial steady permanent magnet synchronous generators are an important alternative to wind turbine generators today due to their high torque / mass ratio and the fact that they are suitable for direct drive systems at low speeds. Since the stators of such generators are in circular disc shaped, they can be designed as multi-pole with having high power density. Because of these superiority, they have an important area of low-speed applications such as wind turbines because they allow energy to be generated even at low speeds below 2 m/s of wind speed. In this study, the design and simulation of a permanent magnet axial flux coreless synchronous generator were actualized. The generator was designed as two stators and three-rotors, and also by placing permanent magnets onto the single edge of the side-rotors and double edges of the middle-rotor to provide a homogeneous flux distribution and to obtain maximum power from the generator. Also, no core was used in the stator of designed generator. Thus, the generator was provided with both reduced iron losses and lighter weight. For three-dimensional electromagnetic analysis of the designed generator, the output parameters of the generator were optimized by using the finite element method. As a result of the analysis and optimization processes of the designed generator, it was concluded that the most efficient results were obtained at 500 rpm; in this case the effective output voltage per phase of the generator is 84.84 V, the effective output power is 1.8 kW and the efficiency was calculated as 93,28%.