Design and Development of a Novel High Voltage Gain, High-Efficiency Bidirectional DC-DC Converter for Storage Interface

A novel bidirectional dc-dc converter having high voltage gain capability with high efficiency is proposed in this paper for interfacing storage in a range of applications. The proposed converter steps up (boost) the voltage in one direction while stepping it down (buck) in the other direction of operation. An attractive feature of the proposed converter is the symmetry of its operating modes. It also has inherent soft-switching capability during turn ON of the switches, enabling high switching frequency operation. This, coupled with the fact that the proposed converter uses only one coupled inductor for both boost and buck modes, leads to a compact system. A clamped capacitor network is used to recover the leakage energy. Circuit description, design, and loss calculations for both buck and boost modes are explained. The bidirectional converter is designed for a voltage gain of 10 and (1/10) in the boost and buck modes, respectively. A 500 W laboratory prototype of the proposed converter has been developed and tested under rated conditions. Even for a large voltage gain of 10, a peak efficiency in excess of 94% is achieved, which is not possible with conventional converters. All the results of this work are included.