**4. Control**

The control consists of two loops; the loop of the voltage or the fast loop and the loop of he PEM or the slow loop. The voltage controller is responsible of controlling the output voltage of the converter, keeping this in a constant value defined by the user even for load variations. The PEM controller is responsible of controlling the operation of the PEM, keeping it in its optimal point that is, producing the electrical power requested by the load with a minimum current and consequently with a minimum of hydrogen consumption. The control structure of the converter as described is represented in Figure 26.

**5. Experimental setup and results**

its stability and dynamics.

**Figure 27.** Experimental setup of the system.

The experimental setup is represented in Figure 27. It is used to test the all system composed by the PEM Mark 1020, the SRC and the load. The load is composed by a set of several resistors connected in series, whose variation is performed by a manual switch. The fuel pressure that provides a PEM stack is monitored by a standard dial pressure gauge, which maintains it constant in the range of 0.3 to 0.5bar. The ventilator is used to inject the oxidant flow necessary into the stack in order to produce the electrochemical reaction. The voltage of 26.06V repre‐

Methodology of Designing Power Converters for Fuel Cell Based Systems: A Resonant Approach

http://dx.doi.org/10.5772/54674

353

The experimental results corresponding to the output voltage and current, the PI controller and the resonant current, are presented in this section to validate experimentally the SRC in

sented by the multimetter corresponds to the open-circuit voltage of the PEM.

**Figure 26.** Control structure of the SRC.
