Mathematical Model Building Of Claw-pole Alternator And Its Performance Optimization

Along with the increasing electric load in the mobile, the requirements for themobile electric system were increasing as well. The performance and efficiency ofthe mobile’s claw-pole alternator could not meet the increasing requirements anymore. So based on the project14V/1kW claw-pole alternator and taking it as theresearch object, the alternator’s mathematical model was established in the paper.The electromagnetic performance of the alternator’s calculation model wassimulated and analyzed by machine design software, the relevant parts of thealternator’s mathematical model was corrected and improved. Parameter analysisand optimization design of the model’s main structure parameters were done byAnsoft, to improve the alternator’s mathematical model as far as possible and tomeet the design requirements of high performance claw-pole alternator.The claw-pole alternator’s electromagnetic field finite element model wasestablished by referring to the basic theory of the electromagnetic field. Combinedwith FFT harmonic decomposition theory, the Back-EMF calculation based onharmonic decomposition in the claw-pole alternator was deduced, and the same asthe rule of waveform distortion. The important effect and the rule of air gapmagnetic field waveform distortion in claw-pole alternator were deduced. The3Dfinite element model used for electromagnetic field analysis was established byMaxwell3D, and the basic electromagnetic field distributions of the alternator’scomplex structure were obtained. Based on Fourier decomposition, the Back-EMFharmonic analysis was emphasized deduced. The air-gap magnetic field and itsharmonic analysis were deduced. The basic theory of optimization design wasquoted and the alternator’s claw pole optimization model was established.Correspondingly, the harmonic composition and size were being compared andanalyzed. Based on it, by comparing and analyzing the harmonic composition andthe ratio in different bevel structure, the extremely bevel of rotor claw wasoptimized. And output performance of the generator, such as efficiency, wasimproved. Finally, the performance test of the project claw-pole alternator wasdone, having it compared with the optimization model’s simulation electromagneticperformance. The correctness of the modeling analysis and optimal selection results was verified in the paper.