Simulation and experiment on reducing electromagnetic vibration and noise of claw-pole alternators

Noise of motors is becoming a more and more significant topic of research due to increasing attention to noise pollution and gradual stricter standards. Claw-pole alternators have been used all over the world with an annual production of above 400million. As for reducing electromagnetic vibration and noise of claw-pole alternators, a method of magnet pole edge cutting based pole-arc coefficient theory is proposed to reduce excitation force waves, and a mechanical impedance model is built to calculate resonant frequency of stator core and housing accurately. With guide of simulation, the appropriate pole-arc coefficient can be selected by Fourier Transformation of magnetic flux density. Experimental results show the validity of proposed method to reduce electromagnetic vibration and noise, and there is a strong correlation among magnet pole parameters, pole-arc coefficient and electromagnetic vibration. The study also contributes to the calculation of electromagnetic vibration and noise and the magnet pole optimization of claw-pole alternators.