Analysis and control of bidirectional DC/DC converter for PEM fuel cell applications

Since the fuel cell system has a slow dynamics by nature, it is recommended to have an additional auxiliary power such as ultra-capacitors or battery during transients to improve system performance in stationary power and transportation applications. Using ultracapacitors and bidirectional converter with fuel cell system can be a possible solution to the problem of slow dynamics of the fuel cell system. In this paper, we present a combined small signal ac equivalent circuit model consisting of a bidirectional converter, a PEM fuel cell, and an ultracapacitor for the purpose to design an appropriate controller for the bidirectional converter. Transient performance of the whole system including fuel cell model, ultracapacitor and bidirectional converter was simulated in Matlab Simulink environment.