An LPV control approach for a fuel cell power generator air supply system

In this paper, the control of the air supply system of a fuel cell power generator is addressed. The management of the air dynamic entering the fuel cell is assured by the control of the air flow of a compressor. The air supply subsystem is controlled to keep a desired oxygen excess ratio, this allows to improve the fuel cell performance. Linear Matrix Inequalities (LMI) tools are extensively used in this paper as a solution to the multivariable robust control problem. Robust multivariable H_∞ controllers are considered. A special interest is also given to reduced order controllers, specifically simple PI structures with desired H_∞ performances. The models used for control implementation were identified from measures on a real test-bench set-up. Two control strategies are proposed, first a speed controller for the air compressor is designed; then the problem of a robust control of the system subject to some model uncertainties is solved using the Linear Parameter Varying (LPV) approach. The validation of the closed-loop control strategies is achieved using time-domain simulation analysis and the gain scheduled approach.