Fast Evaluation of High Frequency Electromagnetic Force and Vibration for Electrical Machines Based on Field Reconstruction Technique

In this paper a semi-analytical method is introduced to calculate the high frequency electromagnetic force and vibration in electrical machines. Firstly, an efficient field reconstruction (FR) technique is utilized to calculate the high frequency magnetic field and force harmonics which are excited by current harmonics, such as the PWM side-band current harmonics in inverter fed machines. Then, the structural transfer function of the machine structure is obtained by static structural analysis and modal analysis. Thereafter, the vibration caused by high frequency current harmonics can be computed instantly by mode superposition. The proposed method is verified by the experiment results at the end of this paper.