SEPIC converter with an LC regenerative snubber for EV applications

A Single-Ended Primary-Inductor Converter (SEPIC) converter with an Inductor-Capacitor (LC) regenerative snubber is proposed to reduce Electromagnetic Interference (EMI) for Electric Vehicle (EV) applications. The switching energy is transferred through a capacitor to an inductor which is coupled to SEPIC inductors. This technique reduces the number of components and also returns some of switching energy to SEPIC converter. The mathematical analysis and optimization of LC snubber with respect to number of turns is also presented. Spice simulations and experimental results are provided to verify its performance. The proposed LC regenerative snubber reduces the peak voltage by 16 V on the switching transistor during the switching transient. It is also indicated that 8 dB reduction is achieved in the EMI measurements at ringing frequency and 10 dB reduction at high frequency band.