In the first part of this paper a stand-alone power system based on a proton exchange membrane fuel cell (PEM) fuel cell stack is designed using a developed tool. The fuel cell power system supplies electricity to the user load without being connected to the electric grid. This kind of power system is developed in the isolated regions. The load analysis, the design requirements and the PEM fuel cell stack design have been performed in the first part of this article. The aforementioned tasks have been implemented by using the Microsoft Excel software. In this way a dedicated design tool has been resulted. The advantages of using this tools are the rapid prototyping the stand-alone fuel cell power systems. The fuel cell power system consist of a reformer, PEM fuel cell stack, battery pack connected with a bidirectional half-bridge dc-dc converter, and power conditioning units (PCU) to give the adequate system topology. The generator sources (battery, fuel cell) are designed to meet the requirements of a user load. During the start-up of the fuel cell process, the user load is powered totally by a battery pack. A proton exchange membrane (PEM) fuel cell is used to keep the system’s reliability at the same level as for the conventional system while decreasing the environmental impact of the whole system. The PEM fuel cell consumes gases which are produced by a reformer to meet the user load demand. Power conditioning units are appropriate for the conversion and dispatch the energy between the components of the system.
