Optimization for Electromagnetic Noise Reduction in Claw Pole Alternator by Rotor Claw Chamfering

The electromagnetic noise of a claw pole alternator is minimized by rotor claw chamfering in this paper. Taguchi method was first applied to evaluate the importance of all of the six chamfer parameters on the output current and the main magnetic force harmonic, and three strongly influential parameters were later selected. Subsequently, the mathematical models of the output current and the sound power level with respect to the three chamfer parameters were developed using the response surface method. Finally, the three parameters were further optimized using the genetic algorithm. A prototype of the optimally designed claw pole alternator was manufactured and its performance was tested. Results show that the rotor claw chamfer does not decrease the output current but can reduce the noise significantly. The sound power level is decreased by more than 15 dB(A) after optimization. The trailing edge chamfer is better than the leading edge chamfer regarding noise reduction.