The Eddy Current Loss Calculation And Analysis Of Claw Pole Rotor And Performance Optimization For Alternator

Along with the increasing power load in car, and the more comfort and energy saving requirement for car, so the claw-pole alternator should meet the higher and more reliable’s performance. Due to its light weight, small size, simple structure and other characteristics, it was widely used in car. But, the special structure of claw-pole rotor in alternator made that it had some disadvtange:low efficiency, big magnetic flux leakage and electromagnetic noise. So, it was very necessary to make electromagnetic analysis and reasonable parameter optimization design.The research object of the paper was based on practual claw-pole alternator of 14V/lkW, and the three-dimensinonal finite element model was established based on the basic theory of electromagnetic field. For the established model, the article applied finite element software to calculate and analyse the motor’s magnetic distribution under no-load and load respectively, and the Fourier decomposition was made for air-gap magnetic field. The rotor Eddy-current loss was calculated and the distribution of Eddy-current density was analysed, and the iron loss was calculated at rated speed, then the iron loss was analysed under different speed, at last the iron loss curve is obtained. According to the relationship of the claw pole size and appling to the theory and method of electric and electronic’s, the pole tip pole arc and pole root pole arc coefficient were selected as optimization variables, and the efficient and electromagnetic noise were selected as optimization object, then the optimization model was established and it made optimization select for rotor size. The efficient and the air-gap magnetic field of different model was calculated and analysed in the 3D finite element electromagnetic field, then the optimal model is obtained by conparison and analysis, which improved the output performance of the alternator.