Saturation Current Calculation for Asymmetric Common Mode Choke in Dual-Mode EMI Filter

To enable the CM choke to function as both CM and DM, a dual-mode filter, an asymmetric CM choke is utilized to increase the leakage inductance thereby enhancing the DM performance. The aim of this work is to establish a calculation process for the saturation current to prevent core saturation. A coupling turns n is proposed to account for imperfect coupling. The product nN of the number of coupling turns and the number of winding turns is used to calculate the saturation current of the leakage inductance. The proposed calculation process is verified with experimental measurements.