Analysis of Fuel Cell Electric Vehicle Performance Under Standard Electric Vehicle Driving Protocol

Abstract

The paper studies and analyzes electric vehicle engines powered by hydrogen under the WLTP standard driving protocol. The driving range extension is estimated using a specific protocol developed for FCEV compared with the standard value for battery electric vehicles. The driving range is extended by 10 km, averaging over the four protocols, with a maximum of 11.6 km for the FTP-75 and a minimum of 7.7 km for the WLTP. This driving range extension represents a 1.8% driving range improvement, on average. Applying the FCEV current weight, the driving range is extended to 18.9 km and 20.4 km, on average, when using power source energy capacity standards for BEVs and FCEVs.

1. Introduction

Commercial and private transport represents approximately 30% of global energy consumption in developed countries [1,2,3]. The energy source for transportation mainly derives from fossil fuels, which produce nearly 16.2% of global greenhouse gas (GHG) emissions [4]. The domestic transport GHG emissions steadily increased during the last decade, except for the disruption period of the COVID-19 pandemic [5]. This continuous growth in GHG emissions causes environmental problems, like climate change and global warming, resulting in unexpected natural disasters (flooding, drought) [6,7,8]. Political decisions have been adopted to prevent the risk of excessive atmospheric GHG concentration (Kyoto Protocol, Doha Amendment, Paris World Climate Summit, UN Climate Change Conference (COP26), Glasgow) [9,10,11,12]. Among the proposed measurements, the progressive replacement of an Internal Combustion Engine (ICE) by electric vehicles is the most representative [13,14,15,16]. In this context, electric vehicles powered by batteries or fuel cells appear as a promising solution to the ICE replacement.

Fuel cell engines operate with hydrogen either produced in an electrolyzer or stored in tanks. Despite the recent application of hydrogen fuel cell engines to the transportation sector, the impetus provided by large industrial companies in the automotive area, especially in Japan and South Korea, is causing vehicles powered by hydrogen engines with fuel cells to become increasingly common [17,18,19,20].

Today, the car manufacturers offer two types of electric vehicles, battery-powered and fuel cell. The power source that supplies electric energy to the vehicle is the principal difference between the two types. Battery-powered cars use a lithium battery to generate the electric current that powers the vehicle’s electric engine; fuel cell cars use a hydrogen storage tank to obtain the electric current through a fuel cell that converts the hydrogen into electricity. While electricity generation is a direct process in battery-powered cars, with the battery acting as the energy storage system, in fuel cell vehicles, the system requires an intermediate device, the fuel cell, to produce available electric current from the storage energy system, the hydrogen tank. Therefore, the energy system behavior in delivering energy differs for each power type; consequently, any applied protocol produces different results. Electric vehicle performance has been defined by specific protocols (NEDC, WLTP, FTP-75, JC08) aimed at estimating the electric vehicle driving range under specific driving conditions [21,22,23,24,25,26,27,28]. Nevertheless, these protocols are specifically developed for battery electric vehicles (BEVs) powered by lithium batteries. Because the performance of a lithium battery and a fuel cell is different, it is necessary to characterize the performance of a hydrogen fuel cell engine to adapt the protocol to its specific behavior [29,30,31,32].

Among the existing fuel cells, the Proton Exchange Membrane (PEM) type is the most suitable one for electric vehicles due to its rapid response [33,34,35], although Solid Oxide (SOFC) can also be used [36]. Therefore, we focus on the characterization process of the hydrogen fuel cell engine in a PEM unit.

Table 1. Characteristics of the PEM cells.

Electrolyte	Solid Polymeric Membrane
Operational temperature range (°C)	50–100
Charge carrier	Proton (H+)
Power range (kW)	1–100
Advantages	Quick start Low operational temperature Low corrosion Low maintenance Light Low size
Disadvantages	Expensive catalyzer Sensitive to hydrogen impurities
Efficiency (%)	40–60
Application sector	Transportation Residential use

shows the advantages and disadvantages of the PEM cells.

The study is trying to highlight how fuel cell electric vehicles may not perform as well as expected when subjected to certain standard protocols designed for batteries. This could potentially impact the driving range of these vehicles, which may be lower than what is officially advertised. The paper also focuses on the implications it may have for the future of fuel cell technology in the automotive industry.

Since a protocol for fuel cell electric vehicle performance under specific driving conditions has not been developed, it is necessary to run an analysis on FCEV performance under a standard driving protocol for electric vehicles to determine FCEV behavior regarding driving range, which is a critical parameter for assessing an electric vehicle’s performance in the current standard protocol. It is true that fuel cell technology is not yet widely implemented in electric vehicles, which means that no standard protocols exist for this technology. This situation is problematic for fuel-cell electric vehicles, and we believe the electric vehicle community needs to pay attention to this issue. The existing problem penalizes fuel cell technology using the lithium battery, which, in our opinion, is unfair. We will explain how fuel-cell electric vehicles can perform better than lithium-battery cars if the appropriate driving conditions are fulfilled.

The present study contributes to the current state of the art in evaluating electric vehicle performance by analyzing the specific behavior of fuel cells powering an electric vehicle, focusing on how the fuel cell delivers energy compared with a lithium battery under particular driving conditions imposed by a standard protocol.

2. Materials and Methods

2.1. Protocol Characteristics

Electric vehicle protocols run under different dynamic conditions according to the defined specifications for every case. The tested parameters to evaluate the performance of an electric vehicle are the running time, the maximum distance, the average speed, and the acceleration.

Table 2. Test characteristics for electric vehicle performance driving cycles.

	NEDC	WLTP Class 1	WLTP Class 2	WLTP Class 3	FTP-75	JC08
Time (s)	1180	1611	1800	1800	1877	1204
Distance (km)	11	11.43	22.65	23.27	17.7	8.17
Max. speed (km/h)	120	64.4	123.1	131.3	91.2	81.6
Average speed (km/h)	33.6	26.8	50.4	51.8	33.8	24.4
Max. acceleration (m/s2)	1	0.76	0.96	1.58	1.57	1.56

summarizes the values of the parameters mentioned above for every protocol. In the case of WLTP, three configurations arise depending on the engine power to vehicle weight ratio (PWr), which is measured in W/kg [37]. According to the PWr value, the WLTP protocol is divided in three classes:

• Class 1: Low-power vehicles (PWr < 22);
• Class 2: Medium-power vehicles (22 < PWr < 34);
• Class 3: High-power vehicles (PWr > 34).

Most modern electric vehicles have a PWr value between 40 and 100, matching class 3. However, some of the bus and van models have a PWr matching class 2 [23,24].

2.2. Dynamic Analysis

To analyze the performance of an electric vehicle equipped with a lithium battery or a fuel cell, we decompose the protocol in segments where dynamic conditions, speed or acceleration, remain constant. We assume that every segment follows a linear behavior; therefore, three-segment types arise: acceleration, deceleration, and constant speed.

Using dynamic laws, we define the acceleration as

$$a={\displaystyle \frac{v_f-v_i}{t}}$$

(1)

where v represents the vehicle speed, with sub-indexes i and f for the initial and final state of the segment, and t is the segment time interval.

For a better understanding, we assign I, II, and III to acceleration, constant speed, and deceleration.

Disaggregating the protocol in segments and applying the abovementioned nomenclature, we can represent the protocol as in Figure 1.

To determine the required energy to cover the test distance, we apply the following expression:

$$\xi ={\displaystyle \sum _{i=1}^n{P}_i{t}_i}$$

(2)

where P is the required power at every segment, i, and n is the number of segments in which the protocol is divided.

Power derives from the classical dynamic expression:

$$P_m=F{v}_{av}$$

(3)

where F is the global dynamic force and v_av is the average speed of the corresponding segment.

Global dynamic force is the sum of inertial, drag, rolling, and weight force, mathematically expressed as

$$F=ma+{\displaystyle \frac{1}{2}}{\rho }_{air}{A}_f{C}_x{v}_{av}^2+\mu mg+mg\sin \alpha$$

(4)

where m is the vehicle mass, A_f is the front surface area, C_x is the vehicle aerodynamic coefficient, µ is the rolling coefficient, ρ_air is the air density, and α is the road slope.

Replacing Equations (1) and (4) in Equation (3), applying the definition of average speed, and considering horizontal road, we obtain

$$P_m=m{v}_{av}{\displaystyle \frac{v_f-v_i}{t}}+\kappa v_{av}{\left({\displaystyle \frac{v_f+v_i}{2}}\right)}^2+C{v}_{av}$$

(5)

where

$$\kappa ={\displaystyle \frac{1}{2}}{\rho }_{air}{A}_f{C}_x\hspace{1em};\hspace{1em}C=\mu mg$$

(6)

Mechanic power derives from electric energy through a conversion mechanism. Considering the transmission efficiency as η_tr, we obtain

$$P_m=P_{el}{\eta }_{tr}$$

(7)

Now, expressing the electric power, P_el, in terms of electric current, and combining Equations (5) and (7), we obtain

$${\left.I_j\right|}_{j=I,II,III}={\displaystyle \frac{1}{V_{op}}}{\displaystyle \sum _{j=1}^n\left[m{v}_{av,j}\frac{v_{f,j}-v_{i,j}}{t_j}+\kappa v_{av,j}{\left(\frac{v_{f,j}+v_{i,j}}{2}\right)}^2+C{v}_{av,j}\right]}\hspace{1em}$$

(8)

Equation (8) defines the required electric current to run the vehicle under the specific driving conditions for every route segment.

3. Methodology

To address the existing problem, we apply the standard protocols (NEDC, WLTP, FTP-75, JC08) to a fuel-cell electric vehicle to evaluate the fuel-cell performance and determine the resulting driving range.

The methodological procedure evaluates the fuel cell response at the consecutive steps that every standard protocol includes. The process analyzes the energy demand according to the protocol dynamic driving conditions and how the fuel cell-hydrogen reservoir tank system reacts to this requirement.

We use the same energy capacity for the power source system to develop a fair comparison between fuel cells and lithium batteries so that the available energy is identical for the two configurations. Based on this premise, since the applied protocol is the same for the two power sources, electric battery and fuel cell, we may conclude if the fuel cell performs better than the lithium battery, using the driving range as the evaluation key parameter.

The developed methodology consisted of reproducing the procedures applied by the standard protocols, NEDC, WLTP, FTP-75, and JC08, to the fuel cell electric vehicle, following the standard profile shown in the figures that follow.

The left section of the NEDC protocol, marked as UDC section in Figure 2, corresponds to the urban circuit, while the right section (EUDC) represents the interurban circuit. In the urban circuit, the method involves four repetitive tests under equal driving conditions, each running for one kilometer at a maximum speed of 50 km/h; in the interurban circuit, the running distance is 7 km, with a maximum vehicle speed of 120 km/h.

Figure 3 shows the WLTP protocol profile.

Because the majority of the current electric vehicles belong to class 3, we apply the WLTP protocol to this class; therefore, the only profile used for testing corresponds to the bottom one in Figure 3.

Regarding the protocol FTP-75 (Figure 4), we mention that it is only applicable to light vehicles. We follow the FTP-75 directions, applying the three testing sections: an initial one corresponding to the cold starting (transient process), a second one corresponding to the stabilized process, and a final one for the hot starting.

The methodology used in the testing process corresponds to the time and dynamic conditions shown in Figure 4 to match the FTP-75 protocol.

Finally, we run the JC08 test cycle (Figure 5) under identical conditions for the original protocol, simulating congested urban traffic conditions, and encompassing situations such as idling periods and frequent acceleration and deceleration. Therefore, we performed the test twice: once with a cold engine and once with a warm engine.

In the lithium-battery power system, the process evaluates the performance by calculating the charge extracted from the battery due to the energy requirements, according to the driving conditions. The calculation method computes the percentage of capacity corresponding to every step of the protocol and determines the associated depth of discharge (DOD); the process continues until the battery is completely depleted.

The methodology establishes the driving range from the associated distance for every cycle and the number of cycle repetitions. To obtain a more accurate prediction of the electric vehicle driving range, the method corrects the battery capacity at every step as a function of the discharge rate, which is calculated from the power requirement and operational voltage.

For the fuel cell power system, the method operates similarly, with the only difference being to determine the hydrogen consumed to power the electric vehicle at every step of the protocol since the fuel cell depends on hydrogen supply to operate.

The procedure involves calculating the mass of hydrogen consumed at each step and determining the total mass for a single cycle by subtracting it from the initial mass in the hydrogen tank. This process repeats until the tank is empty. Finally, the driving range is calculated using the corresponding distance for a single cycle and the number of cycle repetitions.

Fuel Cell Design

To design the fuel cell, we establish the operational conditions and the electric vehicle characteristics powered by the fuel cell. We select a Toyota bZ4X 200E Advance 4 × 2 [38] from the 2023 year as a test model for our analysis. The electric engine operates at 355 VDC (continuous current), powered by a lithium-ion battery of 71.4 kWh (energy capacity). The battery weight is 420 kg.

The PEMFC operates with gaseous hydrogen and air, generating water in the liquid or vapor phase.

Table 3. Properties of the tested PEMFC [39].

Fuel	LHV (MJ/kg)	HHV (MJ/kg)	LHV (MJ/m3)	HHV (MJ/m3)	Ignition Energy (MJ)	Self-Ignition Point (°C)	Boling Point (°C)	Freezing Point (°C)
H2	119.9	141.6	10.8	12.7	0.017	585	−252	−260

lists the properties of the PEMFC.

LHV and HHV account for low and high combustion heat.

To obtain the required energy mentioned above, we need the following hydrogen mass:

$$m_{H_2}={\displaystyle \frac{{\xi }_{FC}}{{\left(HV\right)}_{av}{\eta }_{FC}}}$$

(9)

where η_FC is the PEMFC efficiency, and (HV)_av represents the average combustion heat, which is obtained from the following expression:

$$m_{H_2}={\displaystyle \frac{{\xi }_{FC}}{{\left(HV\right)}_{av}{\eta }_{FC}}}$$

(10)

Hydrogen for fuel cells in electric vehicles is currently compressed to reduce the size of the hydrogen tank. Considering a compression pressure of 700 bar, and an average tank size of 87 L, which is a regular size for a SUV [40], the hydrogen mass is as follows:

$$m_{H_2}=V_{H_2}{\rho }_{H_2}{P}_{H_2}=(0.087)(0.09)(700)=5.481\hspace{0.33em}\mathrm{kg}$$

(11)

We use a density of 0.09 kg/m³ for the hydrogen [39].

Considering an average PEMFC efficiency of 50%, which is a current value [41,42], applying data from Table 3 to Equation (10), and replacing in Equation (9), we obtain

$${\xi }_{FC}=m_{H_2}{\left(HV\right)}_{av}{\eta }_{FC}=(5.481)(36.32)(0.5)=99.53\hspace{0.33em}\mathrm{kWh}$$

(12)

The total weight of the PEMFC, including structure, hydrogen, and tank mass [43,44], is as follows:

$$m_{FC}=m_{st}+m_{tk}+m_{H_2}=200+96+5.48=301.48\hspace{0.33em}\mathrm{kg}$$

(13)

Sub-indexes st, tk, and H₂ account for the structure, tank, and hydrogen.

4. Results

Simulation of PEMFC Driving Range

Using the dynamic properties of the selected electric vehicle and considering the designed PEMFC, we obtain the following:

$$m_{EV}=m_{vh}+m_{FC}+m_{aux-bat}=1550+301.48+80=1931.48\hspace{0.33em}\mathrm{kg}$$

(14)

Sub-indexes vh, FC, and aux-bat account for the vehicle, fuel cell, and auxiliary battery.

We added an auxiliary battery to service vehicle ancillary equipment.

Retrieving Equation (6), we have

$$\begin{array}{l}\kappa ={\displaystyle \frac{1}{2}}(1.2)(2.25)(0.29)=0.39\hspace{0.33em}\mathrm{kg}/\mathrm{m}\\ C=(0.025)(1930)(9.8)=472.85\hspace{0.33em}\mathrm{N}\end{array}$$

(15)

We obtain the electric vehicle driving range from the following expression:

$$DR={\displaystyle \frac{{\xi }_{FC}}{{\eta }_{tr}{\displaystyle \sum _{i=1}^n\left[m{v}_{av,j}\frac{v_{f,j}-v_{i,j}}{t_j}+\kappa v_{av,j}{\left(\frac{v_{f,j}+v_{i,j}}{2}\right)}^2+C{v}_{av,j}\right]t_i}}}$$

(16)

Applying the specific driving conditions defined for every protocol according to the protocol profiles, Figure 2, Figure 3 and Figure 4, and 5 for NEDC, WLTP, FTP-75, and JC08, respectively, to Equation (16), we obtain the corresponding driving range.

The energy value and the vehicle mass correspond to the ones obtained in Equations (12) and (14). Coefficients κ and C derive from Equation (15).

Since we do not use the global energy of the power source in every cycle of any protocol, we obtain the driving range, repeating the protocol cycle until the power source is exhausted. Therefore, the driving range corresponds to the standard distance of every cycle multiplied by the number of cycle repetitions.

Retrieving data from the literature, we have the following (

Table 4. Distance for standard protocol test cycle.

Protocol	NEDC	WLTP C3	FTP-75	JC08
Cycle distance (km)	11.0	23.25	17.77	8.0

):

In our case, we have the following data (

Table 5. Number of cycle repetitions.

Protocol	NEDC	WLTP C3	FTP-75	JC08
Fuel Cell	46.645	22.069	28.875	64.138
Battery	45.745	21.643	28.317	62.900

):

The fractional number of the cycle repetitions indicates that the last cycle has not been completed because the power source is exhausted before the cycle ends.

We observe that there is a difference between the fuel cell and battery values for any protocol, 1.97% higher for the fuel cell, showing that the fuel cell power source delivers a higher performance when applying any driving protocol.

Combining data from Table 4 and Table 5, we obtain the results shown in

Table 6. Driving range for the PEMFC electric vehicle.

Protocol	NEDC	WLTP C3	FTP-75	JC08
Driving Range (km)	513.1	472.0	640.0	562.0

and

Table 7. Driving range for the battery electric vehicle.

Protocol	NEDC	WLTP C3	FTP-75	JC08
Driving Range (km)	503.2	464.3	628.4	551.4

.

If we apply the driving protocols to an electric vehicle equipped with a lithium battery of the same energy capacity, we obtain the data shown in Table 7.

Next, we compare the results from Table 6 and Table 7.

Table 6, Table 7 and

Table 8. Driving range extension for the PEMFC electric vehicle.

Protocol	NEDC	WLTP C3	FTP-75	JC08
Driving Range extension (km)	9.8	7.7	11.6	10.6
Driving Range increase (%)	2.0	1.7	1.9	1.9

confirm the fuel cell’s higher performance, with a near 2% extended driving range.

For an improved PEMFC efficiency of 60%, the associated energy with the PEMFC is

$${\xi }_{FC}=m_{H_2}{\left(HV\right)}_{av}{\eta }_{FC}=(5.481)(36.32)(0.6)=119.4\hspace{0.33em}\mathrm{kWh}$$

(17)

The driving range extension and percentage increase are shown in

Table 9. Driving range for the electric vehicle with improved PEMFC.

Protocol	NEDC	WLTP C3	FTP-75	JC08
Driving Range (km)	615.7	566.4	768.0	674.4

,

Table 10. Driving range for the battery electric vehicle.

Protocol	NEDC	WLTP C3	FTP-75	JC08
Driving Range (km)	604.1	557.4	754.3	661.9

and

Table 11. Driving range extension for the electric vehicle with improved PEMFC.

Protocol	NEDC	WLTP C3	FTP-75	JC08
Driving Range extension (km)	11.6	9.0	13.7	12.5
Driving Range increase (%)	1.9	1.6	1.8	1.9

.

Table 9, Table 10 and Table 11 exhibit the same fuel cell performance improvement, but an extended driving range, due to a higher fuel cell efficiency.

We consider for the calculation that the lithium battery energy capacity for the BEV equals the energy of the improved fuel cell.

We do not include changes in the vehicle mass variation due to hydrogen consumption in the calculation because of their negligible influence, currently less than 0.5%.

We notice that using the PEMFC extends the driving range by 9.8 km for the standard fuel cell efficiency and 11.7 km for the improved PEMFC, on average. Regarding the driving range percentage increase, the average value is 1.8% for both standard and improved PEMFC.

The previous simulation results correspond to BEV and PEMFC electric vehicles of equal mass. Nevertheless, the weight of a fuel-cell electric vehicle is lower than a battery electric vehicle because the fuel cell is lighter than the battery for equal energy capacity. Based on the tested power source for the previous simulation and the corresponding mass of a BEV and a PEMFC electric vehicle, we can obtain the global mass as the addition of the vehicle’s empty weight plus the battery weight for the BEV and the vehicle’s empty weight plus the hydrogen tank mass, including the compressed gaseous hydrogen, and the fuel cell mass.

The total mass of a BEV and a PEMFC electric vehicle is, therefore, as follows:

$$\begin{array}{l}\hspace{1em}\hspace{1em}\hspace{1em}\hspace{1em}{m}_{BEV}=m_{wg}+m_{bat}=m_{wg}+{\xi }_{bat}{\sigma }_{bat}^{\xi }\\ m_{PEMFC-EV}=m_{wg}+m_{H_2}+m_{tk}+m_{FC}=m_{wg}+m_{H_2}+m_{tk}+{\xi }_{FC}{\sigma }_{FC}^{\xi }\end{array}$$

(18)

where m_wg, m_H2, and m_tk represent the vehicle empty weight and the mass of the compressed hydrogen and hydrogen tank, respectively; ξ is the energy capacity; and σ^ξ the mass-specific energy, with the sub-indexes bat and FC accounting for the battery and fuel cell.

Considering a light-duty vehicle of 1050 kg, a lithium battery, and a PEMFC, and applying the calculation for the two simulated cases before, we have the following for the first simulation case:

$$\begin{array}{l}\hspace{1em}\hspace{1em}{m}_{BEV}=1050+(1000)(99.53)(0.006)=1653.24\hspace{0.33em}\mathrm{kg}\\ m_{PEMFC-EV}=1050+5.481+100+(99.53)(0.625)=1217.69\hspace{0.33em}\mathrm{kg}\end{array}$$

(19)

and the following for the second one:

$$\begin{array}{l}\hspace{1em}\hspace{1em}{m}_{BEV}=1050+(1000)(119.44)(0.006)=1773.89\hspace{0.33em}\mathrm{kg}\\ m_{PEMFC-EV}=1050+5.481+100+(119.44)(0.625)=1230.13\hspace{0.33em}\mathrm{kg}\end{array}$$

(20)

Considering that simulation results for the BEV correspond to a vehicle of mass defined in Equations (18) and (19), and applying the protocols for the new mass of the PEMFC electric vehicle, we obtain the following data (Table 12, Table 13, Table 14 and Table 15):

(a)

Power source energy capacity: 99.53 kWh

Table 12. Driving range for the new PEMFC electric vehicle.

Protocol	NEDC	WLTP C3	FTP-75	JC08
Driving Range (km)	522.0	480.9	648.9	570.9

Table 12. Driving range for the new PEMFC electric vehicle.

Protocol	NEDC	WLTP C3	FTP-75	JC08
Driving Range (km)	522.0	480.9	648.9	570.9

Table 13. Driving range extension for the new PEMFC electric vehicle.

Protocol	NEDC	WLTP C3	FTP-75	JC08
Driving Range extension (km)	18.8	16.6	20.5	19.5
Driving Range increase (%)	3.7	3.6	3.3	3.5

Table 13. Driving range extension for the new PEMFC electric vehicle.

Protocol	NEDC	WLTP C3	FTP-75	JC08
Driving Range extension (km)	18.8	16.6	20.5	19.5
Driving Range increase (%)	3.7	3.6	3.3	3.5

(b)

Power source energy capacity: 119.44 kWh

Table 14. Driving range for the new electric vehicle with improved PEMFC.

Protocol	NEDC	WLTP C3	FTP-75	JC08
Driving Range (km)	624.4	575.2	776.7	683.2

Table 14. Driving range for the new electric vehicle with improved PEMFC.

Protocol	NEDC	WLTP C3	FTP-75	JC08
Driving Range (km)	624.4	575.2	776.7	683.2

Table 15. Driving range extension for the new electric vehicle with improved PEMFC.

Protocol	NEDC	WLTP C3	FTP-75	JC08
Driving Range extension (km)	20.3	17.8	22.4	21.3
Driving Range increase (%)	3.4	3.2	3.0	3.2

Table 15. Driving range extension for the new electric vehicle with improved PEMFC.

Protocol	NEDC	WLTP C3	FTP-75	JC08
Driving Range extension (km)	20.3	17.8	22.4	21.3
Driving Range increase (%)	3.4	3.2	3.0	3.2

We notice the increase in driving range and driving range extension, absolute and percentage, considering the corrected mass of the PEMFC electric vehicle. The driving range is extended by 18.9 km, 3.5% more, for the lower power source energy capacity (99.53 kWh) and by 20.4 km, 3.2% more, for the high power source energy capacity (119.44 kWh).

The above results show the advantages of using PEMFC electric vehicles running under the same driving protocols as the BEV.

5. Discussion

The article indicates that FCEVs can achieve a longer driving distance than anticipated when using the standard protocols designed for battery-powered vehicles. This situation is advantageous for drivers, who typically expect to travel shorter distances than what is actually possible. However, it is relevant to note that the results derived from these protocols are inaccurate and should be adjusted to align with predicted values.

Due to the results derived from the present research, we realize that the current standard protocols are not appropriate for establishing the performance of a fuel cell electric vehicle; therefore, it is necessary to develop a specific protocol focused on reproducing the current evolution of the fuel cell power system as a function of the driving conditions. The new protocol should consider the vehicle mass reduction due to the lower weight of the fuel cell compared to a lithium battery of the same energy capacity and the behavior of a PEMFC submitted to a specific discharge rate.

Among the applications of the so-developed protocol, we can mention, as the most significant one, the accurate determination of the driving range of a fuel cell electric vehicle. Nevertheless, other applications arise, like helping electric vehicle manufacturers enhance power system design based on the expected driving range. An additional application is to adapt the protocol to specific driving conditions for every geographical area according to regional regulations in force.

6. Conclusions

Fuel cell electric vehicles (FCEVs) of equal mass and power source energy capacity show higher performance than battery electric vehicles (BEVs) when subjected to standard driving protocols (NEDC, WLTP, FTP-75, JC08), resulting in extended driving range.

The driving range is extended by 10 km, averaging over the four protocols, with a maximum of 11.6 km for the FTP-75 and a minimum of 7.7 km for the WLTP when considering an identical vehicle mass and power source energy capacity based on standards for the battery electric vehicle. This driving range extension represents a 1.8% driving range improvement, on average.

If we increase power source energy capacity according to standard characteristics of a fuel cell unit that equips an electric vehicle, the driving range extension due to the higher performance increases to 11.7 km, on average, with a maximum of 13.7 km for the FTP-75 protocol and a minimum of 9 km for the WLTP. The resulting driving range improvement is 1.8% as in the case of an electric vehicle equipped with a power source with energy capacity based on battery electric vehicle standards.

The performance improvement is even higher when considering the current weight of a fuel cell electric vehicle, which is lower than the BEV due to the higher weight of the batteries.

Applying the FCEV current weight, the driving range is extended to 18.9 km and 20.4 km, on average, when using power source energy capacity standards for BEV and FCEV. As in the case of equal vehicle mass, the maximum extension in the driving range corresponds to the FTP-75 protocol, with 20.5 km and 22.4 km, and the minimum to the WLTP, with 16.6 km and 17.8 km.

Performance improvement for the application of current FCEVs is in the 3.2–3.5% range, depending on the power source energy capacity.

Fuel cell electric vehicles represent an alternative to battery electric vehicles due to their higher performance and extended driving range.