New high power - high ratio non isolated DC-DC boost converter for Fuel cell applications

We present a new structure of a non isolated DC-DC converter, named interleaved double dual boost (IDD boost), applied in the concept of the power electronic interface for fuel cell stationary applications. In the first part, the operation of the structure is highlighted. The interleaving technique is introduced to solve the problem of high current — low voltage and low current ripple imposed by FC, to reduce the average current, to minimize components losses and to facilitate inductors manufacture. The structure coupling offers a high transformer ratio without degrading much the efficiency which is always a limit of non isolated structures. It also reduces the dimensioning voltage and permits a flexible choice of semiconductors and capacitors. In the second part, in the aim of looking for an optimal converter structure, the study begins by the presentation of all possible system configurations. Then, components losses models are built. A systematical losses evaluation gives us a global view on the interesting features of the IDD boost, the interests and limits of the interleaving technique, the components choice strategy and the optimal system architecture.