The increasing public awareness of energy crisis and environmental protection has led to increased interest in new energy resources. Polymer electrolyte membrane(PEM) fuel cell has been showing up as a promising alternative due to its low operation temperature, solid polymer electrolyte and zero emission in stationary and automotive applications. It is widely accepted that PEM fuel cell only system can't achieve performance similar to internal combustion engines. Fuel cell hybrid power system includes at least one other energy sources with fast dynamics, such as battery or supercapacitor, to compensate the slow dynamics of the fuel cell and collect the regenerate energy. Because of different characteristics of multiple power sources, the efficiency and the life of the hybrid power system mainly depend on the power management strategy. In this thesis, the focal point of the work is the power management strategy of the PEM fuel cell hybrid power system. The main contributions of this thesis include: 1.Firstly, on the basis of the electrochemical principles, a dynamic model of a PEM fuel cell V-I characteristics is proposed. Also, the internal insistence model with temperature effect of the lead-acid battery, the average state model of DC/DC converters, the reduced DC motor model are built in this thesis. 2. Secondly, some simulation results of the dynamics of different PEM fuel cell hybrid system when load is changing are presented in this paper. From these results, we can get the characteristics of different PEM fuel cell hybrid systems. 3. Thirdly, an optimal fuzzy power control and management strategy of the PEM fuel cell/battery hybrid power system is studied. Some key parameters of the member function of the fuzzy controller are optimized. By comparison with other power management strategy, The proposed strategy shows good fuel economy. 4. Fourthly, a real time optimization control strategy for power management in a PEM fuel cell/battery hybrid power system is developed. To reduce the calculation work of the controller, the real time optimization problem is solved in personal computer with MATLAB and the necessary data is exchanged by communication module between the controller and the personal computer.
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