Current source converter topology selection for low frequency ripple current reduction in PEM fuel cell applications

In single phase fuel cell applications normal operation of the power conditioning converter introduces a significant second harmonic current ripple that reduces the power availability of the stack up to 20%, increases heating and reduces stack life. A similar effect can be observed in three phase applications operating under unbalanced loads. Current source dc-dc converter topologies can reduce this problem due to their inherent low frequency filtering capability. In this paper a comparison is made between two candidate current source topologies for fuel cell power conditioners. It is shown through analysis and simulations that the current source full bridge converter shows superior performance in a footprint of reduced size and weight.