Spectral-field design with respect to minimum cogging torque and maximum output power

In this paper a new method for magnetic circuit design using the knowledge of corresponding harmonics in the magnetic field and the cogging torque is presented. At the beginning, different approaches to reduce cogging torque for machines with embedded permanent magnets which were presented in the last years are investigated and compared qualitatively. Afterwards, the new developed method is introduced including basic knowledge about the magnetic field's harmonics and their corresponding cogging torque frequencies for electrical machines with different slot-/pole-combinations. Furthermore, the method is applied to an existing motor and quantitatively compared to the previously discussed methods by using FE-simulations. Finally, the results are compared and a therefrom derived conclusion and outlook is given.