Single-PhaseHigh-Power Fuel Cell Converter With Direct Double-Frequency Ripple Current Control

Abstract

This project proposes a direct double-frequency ripple current control in a single-phase high-power fuelcell converter that can accomplish low-frequency ripple-free input current without using large electrolytic capacitors.Such a ripple current may reduce fuel cell life span. It tends to decrease the fuel cell output capacity because the fuelcell controller trips under instantaneous over-current condition. In this proposed method the content of ripples incurrent is reduced without requirement of extra switching devices. A fuel cell power system that contains a dc–acinverter tends to draw an ac ripple current at twice the output frequency. Such a ripple current may reduce input celllifespan an advanced active control method is proposed to incorporate a current control loop in the dc–dc converter forripple reduction.