Study on Common Mode Current Suppression Method in Motor System

The conducted EMI disturbs the sensitivity device in current mode finally. This paper proposed a new common mode current suppression method after the transfer path of common mode current is analyzed in motor system. The proposed method is that the metal shielding layer with high conductivity is placed between power electronic device and heat sink. The electric field transfer is cut and the parasitical capacitance between the two device and electric field coupling are reduced owing to the metal shielding layer. Suppression of the conducted EMI is achieved by reducing common mode current. The simulation and experiment results indicate the validity of this proposed method. Realization of the proposed method is easily and the cost is very low.