Fuel cell high-power applications

Fuel cells (FCs) hold great promise as a clean energy conversion technology. A large research effort is underway to develop the FC for applications ranging from small portable electronic devices to automotive transport, as well as residential combined heat and power supplies. These applications have a large emerging market and widespread adoption should lead to a reduced dependence on fossil fuels as well as encourage the development of a hydrogen economy. FCs produce low DC voltage, so that it is most often connected to electric networks through a step-up DC/DC converter. This article first introduces electrical characteristics, power electronic requirements, and different types of FCs and is then followed by a discussion of the various topologies of step-up DC/DC converters used for FCs´ power-conditioning system. The examinations of several different approaches to power-conditioning systems for single and multiple FC combinations have been reviewed. High-power DC distributed power systems supplied by FC invokes the need to parallel power modules with interleaving technique. By method of the parallel converter modules with interleaving algorithm for an FC generatorfor high-power applications, inductor size (ferrite core and Litzwire) are simple to design and fabricate, and the FC ripple current can be virtually reduced to zero. As a result, the FC mean current is nearly equal to the FC rms current. The main drawback of the multiphase approach is added circuit complexity, requiring measurement and balancing of each phase current as the larger number of control components illustrates.