Multivariable robust control of a proton exchange membrane fuel cell system

This paper applies multivariable robust control strategies to a proton exchange membrane fuel cell (PEMFC) system. From the system point f view, a PEMFC can be modeled as a two-input-two-output system, where the inputs are air and hydrogen flow rates and the outputs are cell oltage and current. By fixing the output resistance, we aimed to control the cell voltage output by regulating the air and hydrogen flow rates. ue to the nonlinear characteristics of this system, multivariable robust controllers were designed to provide robust performance and to reduce the ydrogen consumption of this system. The study was carried out in three parts. Firstly, the PEMFC system was modeled as multivariable transfer unction matrices using identification techniques, with the un-modeled dynamics treated as system uncertainties and disturbances. Secondly, robust ontrol algorithms were utilized to design multivariable H∞ controllers to deal with system uncertainty and performance requirements. Finally, he designed robust controllers were implemented to control the air and hydrogen flow rates. From the experimental results, multivariable robust ontrol is shown to provide steady output responses and significantly reduce hydrogen consumption. 2007 Elsevier B.V. All rights reserved.