Analysis of Current Mode in High Power Density Boost Converters with Magnetic Coupling

Abstract

In general, a boost converter requires a high current because of applications such as HEVs. It is well known that the multiphase method is downsizing approach for a smoothing capacitor. Additionally, with the transformer-linked method, it is possible to miniaturize the inductor with high currents and realize a light weight and compact performance. The switching boost converter has three current modes: the continuous current mode, critical current mode, and discontinuous current mode. Moreover, the discontinuous current mode is the most complicated of all of the modes. For this reason, the control design is carried out to avoid the discontinuous current mode. However the discontinuous current mode is unavoidable when the load rapidly changes. In this paper, the discontinuous current mode in a two-phase boost chopper circuit with a transformer-linked inductor is analyzed. In addition, we carry out a comparative study of the proposed circuit and conventional circuits.