Characteristics of a novel topology of a DC-AC Converter for Fuel Cells

This paper proposes a novel DC-AC converter topology for fuel cells. The proposed circuit topology has no need smoothing circuit because boosted voltage from first step provides directly to PWM inverter. The notice point is that the output voltage from isolating step (third step) is pulsed waveform, and pulse voltage is also made from DC at the converting step. As the result, the smoothing step will be able to be cut if the demanded voltage in one switching period provides to converting AC step within pulse voltage is output. Furthermore, this topology is expected to achieve ZVS of the PWM switches because pulsed voltage has certainly zero voltage periods in the switching period. As the results, it will be possible to reduce the size of this component. Moreover, input current-ripple is damaged to the life span of fuel cells. Using the topology, the method of input current-ripple reduction is shown. This paper shows the advantage the converter by the experimental results.