Study on two-switch Buck-boost converter with coupling inductance

This paper proposes a two-switch Buck-boost converter with coupling inductance to reduce the diodes reverse recover losses. Based on this converter, characteristics of the synchronous and asynchronous control mode have also been analyzed. The experiment result showed that with the same core volume and the same control mode (synchronous control), the converter with coupling inductance can approach higher power than the traditional one holding with nearly the same efficiency. The proposed asynchronous control mode can not only realize smooth transition between steps up and down, reduce the diodes reverse recovery losses and the additional switch on losses, what´s more, but also improve the efficiency by decreasing the equivalent coupling inductance current pulse.