*2.2. Power System*

The electrical output of the fuel cell is not regulated, the voltage depends on the electrical load and the *H*2 inlet flow. However, the electrical applications need a stable input voltage to improve its operation. Figure 3 shows the general power system diagram, where a power converter connects the output of the fuel cell and the electrical application.

It is necessary to emphasize that this kind of power converter controls the output voltage, and the electrical power becomes the most important variable to be controlled. This power depends on the *H*2 inlet flow.

**Figure 3.** Power system control to stabilize the cell output.
