A Bidirectional Partial Power Processing DC-DC Converter with Voltage Step-Up/Down Capability

As the power level of battery energy storage systems is gradually increasing, traditional full power processing bidirectional dc-dc converters are facing a series of problems such as efficiency, power density, and cost. To address these challenges, this paper presents a soft-switching (ZVS-ZCS) voltage step-up/down bidirectional partial power processing dc-dc converter (ZVS-ZCS SUD BPPC), which improves the converter efficiency and reduces the voltage and current stress. The modulation strategy of the topology in four operating modes was studied to achieve smooth switching between each operating mode and ZVS or ZCS of the power switch. A 300V/1000W prototype are implemented and evaluated, experimental results show that the efficiency can reach more than 99%.