Switching and linear power stages evaluation for PEM fuel cell emulation

Abstract

A fuel cell-based power systems emulator designed to test devices and loads intended to interact with real prototypes is presented. The emulator uses a digital processing device and electrical power systems, evaluating the impact of using either switching or linear power stages in the emulator capabilities. A real fuel cell prototype is emulated using a parameterized physical fuel cell model, which is computed online by a digital device. Also, several power stages not previously used specifically for this application, with different efficiencies and performances, were developed and analysed. One of the power stages was based on a two-inductor step-down DC/DC converter for a switching power stage instead of the classical buck structure that is more prone to duty cycle saturation in transients at low output voltages. The other ones used high-power operational amplifiers for a linear power stage and linear regulators for a scalable linear power stage. Finally, the emulation system and the power stages were evaluated and validated using experimental data of a real fuel cell prototype. Copyright © 2010 John Wiley & Sons, Ltd.