Implementation and Efficiency Calculation of Fuel-Cell Vehicles Using a Bidirectional DC/DC Converter with ZVS

Fuel-cell (FC) vehicles are attracting much interest due to their advantages. In FC-powered vehicles, the application of DC/DC converters is for interfacing between the FC and the DC bus. Due to some of the inherent characteristics of FCs, such as large variations in the output voltage, efficiency improvement for different operation points is vital for optimal performance. Moreover, the bidirectional operation can be useful, for example, to charge supercapacitors in electric vehicles (EVs). In this article, the role of a DC/DC converter is as part of the interface system, and efficiency analysis is performed for an EV application. The design and application of the DC/DC converter are optimised based on the EV application's use case scenario. First, the converter's efficiency is analysed for a range of switching frequencies, input voltages, and duty cycles, with basic operations considered later. All the required relations and operating conditions are explained, and simulation results confirm the theoretical analysis.