An Investigation of Zero-Voltage-Switching Condition in a High-Voltage-Gain Bidirectional DC–DC Converter

This paper analyzes the zero-voltage switching (ZVS) for all switches in a high-voltage-gain bidirectional DC–DC converter in triangular conduction mode (TCM) operation without any auxiliary components. From the ZVS condition, the reverse inductor current can be derived, and the required dead-time duration between the main switches and SR switches can be determined, which leads to a reduction in the duty cycle loss. Moreover, the relationship between switching frequency and load in TCM operation can be determined, which helps to reduce the peak-to-peak inductor current and reduce the conduction loss at light load. An experimental prototype of a high-voltage-gain bidirectional DC–DC converter is implemented with a maximum output power of 48 W. The result shows the peak efficiency of 97% and 96.8% in the forward and reverse directions, respectively.