A unidirectional boost chopper with snubber energy regeneration using a coupled inductor

This paper proposes a novel soft-switching boost chopper with a lossless LC snubber, suitable for improving the efficiency of the electric propulsion system of vehicles. The snubber circuit is beneficial owing to the following features: zero-current switching turn-on and zero-voltage switching turn-off are achieved regardless of the operating conditions; it requires only one additional switch with smaller current rating compared to the main switch; the additional switch can be controlled by basic arithmetic; and the main switch is free from additional voltage or current stress caused by the soft-switching operation. Along with theoretical discussions, experimental results are also presented on the circuit behavior and the resulting improvement of the energy conversion efficiency. These results show the usefulness of the chopper for improving the efficiency of electric vehicles.