A simplistic hybrid energy system is composed of the wind turbine, electrolyzer, and PEM fuel cell stack. in view of the high current demand and fast load changes, the hybrid dynamic simulation shows that the fuel cell may be in risk of oxygen starvation and overheating problems. Regarding the safe operation as well as long lifetime of the fuel cell, the effective control manner is expected to regulate both the stack temperature and oxygen excess ratio in the cathode at the desired level. Under the multi-loop nonlinear predictive control framework, the controlled output variables are specified independently by manipulating air (oxygen) and water flowrates, respectively. The dynamic modeling and control implementation are realized in the Matlab-Simulink (TM) environment. Crown Copyright (C) 2009 Published by Elsevier Ltd on behalf of International Association for Hydrogen Energy. All rights reserved.