Theoretical and Experimental Investigation of the Influence of Rotor Claw Pole on Electromagnetic Vibration Noise of Alternators

To investigate the electromagnetic vibration and noise of vehicle-mounted alternators during low-speed operation, an analytical model for the electromagnetic force was established. Furthermore, the harmonic characteristics of the electromagnetic force were thoroughly examined. Based on the developed analytical model, a method is proposed to calculate the relationship between surface intercept line of the claw pole and the harmonic components of the electromagnetic force, the influence of the former on the latter is analyzed. An optimization scheme for the rotor claw pole aimed at reducing the electromagnetic force is proposed. The impacts of the rotor claw pole, both prior to and following optimization, on electromagnetic vibration and noise are modeled and analyzed. The results show that, with the rotor claw pole having undergone optimization, the 36th-order acceleration of the electromagnetic vibration has been reduced by 53%, while the electromagnetic noise also decreases significantly. Tests on the developed prototype show consistency with the calculated results. This work can provide a reference for controlling the electromagnetic vibration noise of alternators.