This paper describes a new zero voltage switching (ZVS) bidirectional DC-DC converter (BDC) module. Compared to existing bidirectional DC-DC converter (BDC) modules for the same application, the new BDC module has the advantage of high efficiency, high power density and isolation. These advantages make the new BDC promising for medium and high power fuel cell, solar cell and battery applications where high power density, high efficiency, high reliability and lightweight power converters are needed.

A real world implementation of 384 V to 48 V and 48 V to 384 V BDC is described, implemented and simulated using existing old components and proposed new power components for power level up to 1.65 kW. A new BDC provides a +13.5% increase in efficiency at 10% load, a +3.4% increase at 50% load and a +1.5% increase at 100% load in both forward and backward mode and more than double power density.

The bidirectional DC-DC converter (BDC) along with energy storage has become a promising option for many high power systems, including battery applications in hybrid and electric vehicle, ups, telecom and grid, fuel cell and solar cell applications in renewable energy and so forth. All these high power systems call for high efficiency from light load to full load, high power density and lightweight.