Optimization Design of EMI Filter with Chaotic PWM in DC-DC Converters

摘要

Electromagnetic interference (EMI) filters are usually used to suppress the conducted EMI for power converters, which will increase the volume, weight and cost of power converters a lot. To improve the power density of power converters, the chaotic pulse width modulation (CPWM) method is firstly proposed to optimize the EMI filter design in this paper. With CPWM, the peak values on the EMI spectrum of power converters can be reduced obviously, the EMI filter is further designed based on the chaotic EMI spectrum in this paper. With the same attenuation amplitudes, the EMI filter using CPWM is compared with the filter using the conventional PWM by calculation. Finally, the optimization design of EMI filter is verified by a Boost converter prototype and the volume of the EMI filter goes down to a third by using CPWM.