**3. Experimental Model (EXM)**

In this section, we will determine the static and the dynamic behaviour of the Ballard Nexa 1200 fuel cell module, which has a rated power of 1.2 kW. To this end, an experimental bench was built, as shown in Figure 7; it consists—in addition to the fuel cell, with its monitoring software—of three metal hydride canisters from Heliocentris with storage capacities of 800 NL hydrogen, an H2 connection Kit 15 bar for connecting the metal canisters, a Nexa 1200 DC/DC converter, a power supply from BK Precision used for the fuel cell starter, Hall effect sensors to measure the voltage and current variables, a programmable DC electronic load from BK Precision and power resistors to make load changes, and a MicroLabBox-dSPACE with Control Desk software plugged into a personal computer for signal acquisition. *Micromachines* **2021**, *12*, x 9 of 15 for the fuel cell starter, Hall effect sensors to measure the voltage and current variables, a programmable DC electronic load from BK Precision and power resistors to make load changes, and a MicroLabBox-dSPACE with Control Desk software plugged into a personal computer for signal acquisition.

**Figure 7.** View of the experimental bench. **Figure 7.** View of the experimental bench.

Ifccurrent (A) 55 56 57 58 59 60 Vfcvoltage 22.89 22.64 22.34 22 21.6 21.13

**Current probe**

### *3.1. Static Characteristics(i–v) of the Fuel Cell 3.1. Static Characteristics(i–v) of the Fuel Cell*

Several points representing the current and the voltage under static conditions of the fuel cell were determined, and are listed in Table 1. The obtained current–voltage characteristics are illustrated by Figure 8. Several points representing the current and the voltage under static conditions of the fuel cell were determined, and are listed in Table 1. The obtained current–voltage characteristics are illustrated by Figure 8.

Ifccurrent (A) 11 12 13 14 15 16 17 18 19 20 Vfcvoltage 28.34 28.16 28 27.86 27.74 27.62 27.52 27.41 27.31 27.21 Ifccurrent (A) 22 23 24 25 26 27 28 29 30 31 Vfcvoltage 27 26.9 26.79 26.68 26.56 26.44 26.32 26.19 26.07 25.94 Ifccurrent (A) 33 34 35 36 37 38 39 40 41 42 Vfcvoltage 25.68 25.55 25.42 25.3 25.17 25.05 24.93 24.82 24.71 24.6 Ifccurrent (A) 44 45 46 47 48 49 50 51 52 53 Vfcvoltage 24.39 24.29 24.19 24.09 23.98 23.88 23.75 23.62 23.47 23.31

**Table 1.** Experimental data of the fuel cell current and voltage.


**Table 1.** Experimental data of the fuel cell current and voltage.

### *3.2. Dynamic Behaviour of the NEXA 1200Fuel Cell 3.2. Dynamic Behaviour of the NEXA 1200Fuel Cell 3.2. Dynamic Behaviour of the NEXA 1200Fuel Cell*

Using a programmable DC electronic load and power resistors, a fuel cell current step change is operated from 13A to 33A after 65.1s. The resulting fuel cell current and voltage are shown in Figure 8 and Figure 9, respectively. Using a programmable DC electronic load and power resistors, a fuel cell current step change is operated from 13A to 33A after 65.1 s. The resulting fuel cell current and voltage are shown in Figures 8 and 9, respectively. Using a programmable DC electronic load and power resistors, a fuel cell current step change is operated from 13A to 33A after 65.1s. The resulting fuel cell current and voltage are shown in Figure 8 and Figure 9, respectively.

mining the parameters of the equivalent electric model RL, and using the experimental responses shown in Figures 8 and 9, we obtained the results listed in Table 2. Figure 10 shows a comparison between the experimental voltage of the fuel cell and that obtained

mining the parameters of the equivalent electric model RL, and using the experimental responses shown in Figures 8 and 9, we obtained the results listed in Table 2. Figure 10 shows a comparison between the experimental voltage of the fuel cell and that obtained

**() (**ષ**) (**ષ**) (s (**∆ **(V(**∆ **(V(**∆ **(V(**∆ **(A (**∆ 20 6.11 3.03 0.98 36.7 154 151.5 4.94

**() (**ષ**) (**ષ**) (s (**∆ **(V(**∆ **(V(**∆ **(V(**∆ **(A (**∆ 20 6.11 3.03 0.98 36.7 154 151.5 4.94

**Figure 9.** Fuel cell current step change. **Figure 9.** Fuel cell current step change. **Figure 9.** Fuel cell current step change.

*3.3. RL Model Parameters*

*3.3. RL Model Parameters*

**Voltage V**

**fc (V)**

**Table 2.** RL circuit parameters.

**Table 2.** RL circuit parameters.

from the RL model. One can show a good fit for the proposed RL model.

from the RL model. One can show a good fit for the proposed RL model.

*Micromachines* 
