Aiming at finding a way to improve commutation and decrease the level of the spark for low-voltage high-current vehicle generators, using asymmetric pole structure, non-uniform commutating pole, single wave windings and oblique brush. This paper concludes the distribution of the flux line and the wave of the air gap magnetic field, analysis on the loading and no loading inner magnetic field with the method of finite element. The results reveal that although the asymmetric structure, the magnetic field created by the main poles is still symmetric and uniform, thus it ensures the provision of suitable medium space for mechanical and electrical energy conversion. It concludes that the commutating pole decreases the magnetic induction contrast to the generator without commutating pole, according to the curve of the gap magnetic field and the distribution of the inner magnetic field. It shows that the EMF has decrease on average by 58.25% under the influence of commutating pole, it have a demonstrable effect on improving commutation. The results show that it can provide the key technical program to the development of low-voltage high-current generator, improve commutation, decrease the level of spark, and inhibit the electromagnetic interference; it will help improve the generator run stability and reliability.
