Transformer-less Boost DC-DC Converter with High Gain and Low Current Ripples for Fuel Cell Vehicles

Around the world, fuel cell generation system has attracted more attention in many applications such as electric vehicle and the utilization of distributed renewable energy source. Nevertheless, the output voltage of the fuel cell terminal is comparatively low, and cannot be supplied forthwith to the power grid or local load. With the object of raising its lower output voltage to a higher DC voltage upon 400V, a transformer-less interleaved DC-DC converter with a high step-up is proposed in this present study. It has the ensuing features: (1) all semiconductors only bear half as much the output voltage. (2) The inherent interleaved structure of the converter can efficaciously diminish the input current ripples to stretch the operation life of a fuel cell. (3) The leakage current can be eliminated greatly due to the common ground structure, which enhances the security and dependability of the system. This paper discusses the functional principle and steady-state characteristics of the given converter thoroughly in CCM & DCM, severally. A 400W experimental model is ultimately established to confirm the correctness of the mentioned conceptual analyses and the possibility of practical application.