High-efficiency fuel cell power conversion system

This study presents a newly designed topology for a fuel cell energy source conversion in order to supply a highly reliable utility power. Because the fuel cell has the power quality of low voltage as well as high current due to the electrochemical reaction, a high step-up DC-DC converter is utilized for boosting the fuel cell voltage up to a constant DC-bus voltage for the utilization of later inverter. Moreover, a current-source sine-wave voltage inverter is designed in the sense of voltage-clamping and soft-switching techniques. In this power conversion scheme, the output voltage has the salient features of lower distortion, fast dynamic regulating speed and insensitivity to load variation, even under nonlinear loads. In addition, experimental results via an example of a PEM fuel cell generation system with 250 watts nominal power rating are given to demonstrate the effectiveness of the proposed power conversion strategy.