A new high efficiency isolated bi-directional DC-DC converter for DC-bus and battery-bank interface

A new bi-directional DC-DC converter is designed and analyzed in this paper. This new topology and its control strategy have completely solved voltage spike issues present in traditional bi-directional DC-DC converters which also have limited power capability and efficiency. This converter can serve as battery bank and DC-bus interface and work in both directions (charging-battery direction and supporting-bus direction) with high efficiency. Operation principles of each block of the circuit and system implementation have been analyzed. Experimental results show high efficiency is able to be achieved in both directions. A 300W in (charging battery) 1500W out (supporting bus) prototype proposed is able to charge battery at 92.9% efficiency (300W) and support bus at 93.6% efficiency (1500W). Higher power level can be easily achieved by reconfiguration or paralleling.