Alleviation of Electromagnetic Interference Noise Using a Resonant Shunt for Balanced Converters

Balanced converter is an effective way to reduce the CM noise. However, the parasitic capacitance between the switch and heat sink leads to resonant problems, resulting in high noise in certain frequency range. This paper proposes a novel coupled inductor structure based on the balanced technique for the Boost converter to further reduce the CM noise at certain frequency range. A shunt resonant path is adopted to offer a maximum suppression. The analytical estimation for shunt winding's performaPnce is provided for better design. Some simulation and experimental results of this new technique are presented to validate its effectiveness. The experiments about the capacitance unbalance, different load current, and reduction of the CM inductor size are also discussed for better understanding of this technique.