Modeling and Design of the Planar Magnetic Integration for Dual-Stage EMI Filters

A planar magnetic integration method of dual-stage electromagnetic interference (EMI) filters is proposed. Common-Mode (CM) inductors, CM and differential-mode (DM) capacitors are integrated into a single planar EIE-type magnetic core, DM inductors are provided by the leakage inductance of CM inductors. A planar magnetic integrated dual-stage EMI filter (IDSEF) is built and tested on the PLECS simulation platform to verify the feasibility of the proposed method. A GaN single-phase inverter and a test platform are developed. Compared with a discrete single-stage EMI filter (DSSEF), the discrete dual-stage EMI filter (DDSEF) achieves weight and volume reductions of 22.57% and 24.42%, respectively. Furthermore, the proposed IDSEF achieves additional reductions of 33.64% in weight and 29.16% in volume relative to the DDSEF. The proposed IDSEF delivers comparable EMI attenuation performance to the DDSEF while significantly reducing the weight and volume of the filter and enhancing the power density of the inverter system.