Advanced Control Strategies for the Oxygen in the Cathode

Abstract

This chapter presents two advanced control strategies based on model predictive control to control the oxygen level in the cathode of a PEM fuel cell system. The objectives are to achieve a better efficiency and to maintain the necessary level of the oxygen in the cathode to prevent short circuit and membrane damage. First, a methodology of control based on Dynamic Matrix Control is proposed. This strategy includes a stationary and dynamic study of the advantages of using a regulating valve for the cathode outlet flow in combination with the compressor motor voltage as manipulated variables in a PEMfuel cell system. The influence of this input variable is exploited by implementing a predictive control strategy based on dynamic matrix control (DMC), using these manipulated variables. The objectives of this control strategy are to regulate both the fuel cell voltage and oxygen excess Ratio in the cathode. Second, a methodology of control based on adaptive predictive control with robust filter (APCWRF) is proposed. The APCWRF is designed for controlling the compressor motor voltage. Because of the wide working range the algorithm isimproved with three different zones supported by three nominal linear models.