A current-controlled fuel cell system with short-time storage for grid feeding application

For generation of required voltages and controlled energy transfer from fuel cell stacks, appropriate converter topologies are necessary. The stability of the stack against degradation and thus the possible lifetime does not meet the requirements for most applications yet. Dynamic fluctuations of the FC output power can accelerate the degradation process. Only a limited fuel cell current is allowed to prevent faster degradation of the FC-stack. A favorable topology for the combination of a fuel cell with a short time energy storage will be discussed. A fast AC-load response is possible in order to balance fluctuated consumer profiles and to improve the quality of the power fed into the grid.