Fuel cell systems can produce clean energy and have attracted the interest of both industrial and basic research in the recent years. They are part of a promising benign and environmentally friendly technology and they can be used both in mobile and stationary applications. A dynamic model was constructed and validated using experimental data based on a specific application, consisting of a high temperature PEM Fuel Cell (FC) working at a constant pressure and a Power Conversion Device that controls the current drawn from the FC. An integrated framework that consists of an online maximum power point prediction algorithm and a non-linear model based control scheme is presented. The proposed framework aims to maintain the fuel cell close to the optimum power point and the corresponding oxygen excess ratio level. Simulation studies show that the proposed control framework results in improved performance regarding the efficient and safe fuel cell operation under varying operating conditions.