A Novel Bi-Directional Isolated Power Flow Dc–Dc Converter for Hybrid System

In Electrical power systems in future uninterruptible power supplies or electrical vehicles may employ hybrid energy sources, such as fuel cells and super capacitors. It will be necessary to efficiently draw the energy from these two sources as well as recharge the energy storage elements by the dc bus. In this paper, a bidirectional isolated dc–dc converter controlled by phase-shift angle and duty cycle for the fuel-cell hybrid energy system is analyzed and designed. The proposed topology minimizes the number of switches and their associated gate driver components by using two high-frequency transformers that combine a half-bridge circuit and a full-bridge circuit together on the primary side. The voltage doubler circuit is employed on the secondary side. The current-fed input can limit the input current ripple that is favorable for fuel cells This paper describes the operation principle of the proposed converter, the ZVS conditions, and the quasi-optimal design in depth. The fuel input voltage is given to the boost converter, where it is stepped up the voltage fed to the coupled transformer and one more half bridge construct connected with series with dc load to obtain 600-V tested to verify the effectiveness of the presented converter can be simulated by using MATLAB/SIMULINK. It can be used for high power applications. Index Term — Bidirectional dc–dc converter, current-fed, fuel cell (FC), phase shift, super capacitor (SC).