Research of high-efficiency DC-DC boost type converter circuits for fuel cell electric vehicles and development of a suitable converter

The voltage obtained from the fuel cell output in Fuel Cell Electric Vehicles (FCEVs) is constantly changing, and this variable output voltage needs to be converted to the appropriate voltage for power transfer in FCEVs. In this study, a new double inductor DC-DC boost converter is proposed that can increase the voltage varying between 25-48V at the output of a 1 kW fuel cell to the 96V level required for power transfer in FCEVs. The main feature of the proposed structure is that it has two inductors and 1 switch. Thanks to this structure, the input and output of the circuit can be converted in a way that is directly proportional to the square of the duty cycle. If this conversion ratio was to be obtained with the traditional single coil boost converter circuit topology, two converters had to be connected in series. By using this structure, both higher voltage conversion gain with low duty periods and similar efficiency to the traditional boost converter were obtained. First of all, the simulation model design and virtual environment analyses of the proposed double inductor DC-DC boost converter were performed. The results obtained from the analysis showed that the efficiency was 92% when the input voltage was 25V and 96% when the input voltage was 48V. Then, the designed converter was also implemented experimentally. The measurements taken from the implemented design were compared with the analysis results obtained from the simulation environment. The results obtained from the experimentally implemented circuit show that the proposed converter operates with 89% efficiency when the input voltage was 25V and with 92.3% efficiency when the input voltage was 48V. It was observed that the efficiency values obtained from the implemented circuit and the efficiency values obtained from the simulation environment were close to each other. These results show that this circuit is also applicable in practice. In the first stage, a 100W initial sample design was made in order to check the applicability of the design. For this reason, simulations were also performed in this direction and the components used in the simulation model were selected according to this power level. It is thought that this structure, which can be used in power transmission applications in FCEVs, can be used in many applications, especially electric and hybrid energy vehicles, by increasing its power with scaling.