Fuel Cell Electric Vehicle Applications Research Articles

Review of Fuel-Cell Electric Vehicles

This paper presents an overview of the status and future prospects of fuel-cell electric vehicles (FC-EVs). As global concerns about emissions escalate, FC-EVs have emerged as a promising substitute for traditional internal combustion engine vehicles. This paper discusses the fundamentals of fuel-cell technology considering the major types of fuel cells that have been researched and delves into the most suitable fuel cells for FC-EV applications, including comparisons with mainstream vehicle technologies. The present state of FC-EVs, ongoing research, and the challenges and opportunities that need to be accounted for are discussed. Furthermore, the comparison between promising proton-exchange membrane fuel cell (PEMFC) and solid oxide fuel cell (SOFC) technologies used in EVs provides valuable insights into their respective strengths and challenges. By synthesizing these aspects, the paper aims to provide a comprehensive understanding and facilitate decision-making for future advancements in sustainable FC-EV transportation, thereby contributing to the realization of a cleaner, greener, and more environmentally friendly future.

Modeling, simulation, and experimental studies of a novel battery charger for fuel cell applications based on a new high step‐up DC‐DC converter

SummaryDuring winter, the proton exchange membrane fuel cell (PEMFC) faces operational challenges, potentially leading to ice formation in membranes and gas technology. To achieve favorable operational conditions and output voltage, suitable power electronic devices are indispensable. Consequently, the fuel cell module links to the battery through a DC‐DC converter. Addressing the necessity for an efficient battery charger in fuel cell electric vehicle applications, this article introduces a new high step‐up DC‐DC converter. It employs a boosting structure, incorporating a coupled inductor to elevate voltage gain while substantially reducing voltage and current stresses on components, a fitting attribute for PEMFC electric vehicle battery chargers. Additionally, the proposed converter boasts high efficiency and a minimal component count. Moreover, the study meticulously explores various operating modes of the converter, offering comprehensive analyses and operational relationships. To evaluate dynamic behavior and ensure stability, the study employs small signal modeling and devises a controller based on the maximum power point tracking principle. MATLAB simulations validate the converter's performance, while a laboratory‐built prototype (48 V input, 220 V output, 500 W) substantiates its characteristics, aligning with theoretical projections. Finally, a comparative analysis between simulation, experimentation, and theoretical calculations validates the converter's functionality. Ultimately, this work emphasizes the critical role of a well‐designed high‐efficiency DC‐DC converter in the context of PEMFC electric vehicle battery charging during challenging winter conditions. The proposed converter's innovative design, minimal componentry, efficiency, and validated performance through simulation, experimentation, and theory underscore its potential significance in enhancing fuel cell electric vehicle technology.

Reliability improvement of multi-phase interleaved DC-DC converters for fuel cell electric vehicle applications

This paper suggests a fast and low-cost method that can be applied in several DC/DC converter topologies for detecting open circuit faults (OCFs) and short circuit faults (SCFs). The suggested method may identify the faults of several power switches even if they occur simultaneously in multi-phase interleaved boost converters (MPh-IBC) by using just the sensors needed to control the converter. This fault detection method (FDM) is based mainly on comparing the measured inductor current and two fault detection thresholds, one for OCFs detection and the other for SCFs detection. This method combined with a corrective strategy to mitigate the negative impacts of OCFs, particularly the significant rise in the ripple of the DC bus voltage and the fuel cell (FC) current, which reduces FC aging and converter reliability. The simulation findings indicate the FDM's excellent performance and speed, as well as its usefulness in detecting defects of many power switches in the converter, with a fault detection time of up to 1.7 µs. The acquired findings further show the excellent effectiveness of the corrective strategy in reducing these ripples in the event of one or two faults.

A non‐isolated high quadratic step‐up converter for fuel cell electric vehicle applications

SummaryThe fuel cell electric vehicles require a dc‐dc converter as a power interface to match the fuel cell voltage to the dc bus. By considering the soft characteristics of the fuel cell source, this work introduces a non‐isolated high quadratic step‐up (HQSU) converter with a wide‐range voltage gain and continuous source current. The proposed converter comprises two synchronously operated active switches and two inductors; it adopts a switched capacitor cell to improve the voltage gain and reduce the voltage stress of the output side components. Further, this work discusses the HQSU converter in terms of operation, steady‐state analysis, design considerations, and non‐ideal and dynamic analysis. In addition, the comprehensive comparison with recent quadratic converters suggests that the proposed HQSU converter has the advantages of higher voltage gain, high effectiveness index, low total voltage stress, and lower SDP rating, along with common ground and non‐inverted output. Furthermore, a 200 W laboratory prototype is fabricated to validate the theoretical findings. The experimental results confirm the good steady‐state and dynamic behavior of the proposed HQSU converter, which achieved an efficiency of 94.2% at rated power.

A Novel High Quadratic Gain Boost Converter for Fuel Cell Electric Vehicle Applications

This work has adopted the concept of asymmetric inductor magnetization to develop a new quadratic converter with the advantages like a wide range quadratic voltage gain and low source current ripple. In addition, the proposed high quadratic converter has achieved reduced voltage stress due to the presence of switched capacitor cell at the output side. Initially, the operation of the converter and steady-state analysis, including efficiency calculations, are explained. In addition, the design and selection of converter components are presented along with a small-signal analysis. Further, a comprehensive comparison with recent high quadratic gain converters is presented. The comparison is made with regard to the total component count, voltage conversion ratio, effectiveness index, electric stress, current ripple, switching device power (SDP) rating, and input current ripple factor. Furthermore, the 150 W laboratory prototype is used to verify the performance of the proposed converter in terms of operation, dynamic response, and efficiency, and the corresponding experimental findings are reported. The wide range voltage gain, low current ripple, and low electric stress features of the proposed converter highlight its superiority in fuel cell electric vehicle applications.

Multirate DAE-simulation and its application in system simulation software for the development of electric vehicles

This work is devoted to the efficient simulation of large multi-physical networks stemming from automated modelling processes in system simulation software. The simulation of hybrid, battery and fuel cell electric vehicle applications requires the coupling of electrical, mechanical, fluid, and thermal networks. Each network is established by combining the connection structure of a graph with physical equations of elementary components and resulting in a DAE (differential algebraic equation). To speed up the simulation a non-iterative multirate time integration co-simulation method for the system of coupled DAEs is established. The power of the multirate method is shown via two representative examples of battery powered electric vehicle with a cooling system for the battery pack and a three phase inverter with a cooling system. This work is an extended version of (Kolmbauer et al. in Scientific Computing in Electrical Engineering (SCEE 2020), Springer, Cham, pp. 231–240, 2021).

Construction of Stable Wide-Temperature-Range Proton Exchange Membranes by Incorporating a Carbonized Metal-Organic Frame into Polybenzimidazoles and Polyacrylamide Hydrogels.

Proton exchange membrane fuel cells (PEMFCs) are promising devices for clean power generation in fuel cell electric vehicles applications. The further request of high-efficiency and cost competitive technology make high-temperature proton exchange membranes utilizing phosphoric acid-doped polybenzimidazole be favored because they can work well up to 180°C without extra humidifier. However, they face quick loss of phosphoric acid below 120°C and resulting in the limits of commercialization. Herein UiO-66 derived carbon (porous carbon-ZrO2 ), comprising branched poly(4,4'-diphenylether-5,5'-bibenzimidazole) and polyacrylamide hydrogels self-assembly (BHC1-4) membranes for wide-temperature-range operation (80-160°C) is presented. These two-phase membranes contained the hygroscopicity of polyacrylamide hydrogels improve the low-temperature proton conductivity, relatively enable the membrane to function at 80°C. An excellent cell performance of BHC2 membrane with high peak power density of 265 and 656mWcm-2 at both 80 and 160°C can be achieved. Furthermore, this membrane exhibits high stability of frequency cold start-ups (from room temperature to 80°C) and long-term cell test at 160°C. The improvement of cell performance and stability of BHC2 membrane indicate a progress of breaking operated temperature limit in existing PEMFCs systems.

A comparison of real-time energy management strategies of FC/SC hybrid power source: Statistical analysis using random cycles

This paper presents a comparative study of two promising real-time energy management strategies for fuel cell electric vehicle applications: adaptive equivalent consumption minimization strategy (A-ECMS), and stochastic dynamic programming (SDP). An off-line algorithm –classic dynamic programming - provides reference results. On-line and off-line strategies are tested both in simulation and using a dedicated test bench completely consistent with an electric scooter powertrain.The hybrid power source combines a fuel cell, a supercapacitor pack and two related power converters. The system model is carefully calibrated using experimental data. This allows meaningful identification of parameters of the various strategies. The model data is determined using a motorcycle certification driving cycle.The robustness of each strategy is then analyzed using a large number of random driving cycles. Experimental and simulation results show that a specific SDP approach, based on Markov chain modeling, has the best overall performance in real-world driving conditions. It achieves the minimum average hydrogen consumption while respecting the state-sustaining constraint. Conversely, the A-ECMS results lack robustness and show poor performance indexes when facing unknown real world power demand profile. In conclusion, the present results indicate SDP is an interesting approach for future hybrid source energy allocation.

Powering the Future through Hydrogen and Polymer Electrolyte Membrane Fuel Cells

To date, the world has been making a massive shift away from fossil fuels towards cleaner energy sources. For the past decade, polymer electrolyte membrane fuel cells (PEMFCs) powered by hydrogen have attracted much attention as a promising candidate for eco-friendly vehicles, i.e. fuel cell electric vehicles (FCEVs), owing to their high power density, high efficiency and zero emission features. Since the world’s first mass production of Tucson ix35 FCEV by Hyundai in 2013, global automotive original equipment manufacturers (OEMs) have focused on commercialising FCEVs. In 2018, Hyundai also unveiled the second generation of the mass-produced FCEV (i.e. Nexo) with improved performances and durability compared with its predecessor. Since then, the global market for PEMFCs for a variety of FCEV applications has been growing very rapidly in terms of both passenger vehicles and medium- and heavy-duty vehicles such as buses and trucks, which require much higher durability than passenger vehicles, i.e. 5000 h for passenger vehicles vs. 25,000 h for heavy-duty vehicles. In addition, PEMFCs are also in demand for other applications including fuel cell electric trains, trams, forklifts, power generators and vessels. We herein present recent advances in how hydrogen and PEMFCs will power the future in a wide range of applications and address key challenges to be resolved in the future.

A Family of Three-Port Three-Level Converter Based on Asymmetrical Bidirectional Half-Bridge Topology for Fuel Cell Electric Vehicle Applications

In this paper, a family of three-port three-level converters (TPTLC) composed of asymmetrical bidirectional half-bridge modules is proposed, which offers the benefits in terms of a simple control scheme, extended soft switching over a wide range of operating conditions, and reduced voltage stress across switches. The proposed converters take advantage of a pulsewidth modulation plus phase shift control technique to regulate the output voltage as well as to control the power flow between different ports independently. A stacked TPTLC is taken as an example to be introduced in detail to gain a thorough insight into the proposed family of converters. The stacked TPTLC can provide a high voltage gain along with a wide voltage gain range without using any transformer, resulting in the improvement in the power density. In order to minimize the conduction loss and reduce the current stress of switches, the root-mean-square current of the inductor and the boundary condition of the phase-shift controller in different operation scenarios are studied. Finally, the feasibility of the proposed concept and effectiveness of the design approach are validated based on the experimental results of a 1-kW, 100-kHz prototype of the stacked TPTLC using gallium nitride switches.

(Invited) Advanced Components Development for Electrochemical Ammonia Synthesis

Ammonia is an essential industrial chemical for agricultural fertilizer, medical intermediates, and energy storage. For fuel cell electric vehicle applications, it can be used as a fuel directly or as a means of hydrogen storage due to its high energy density in the liquid state. Conventional ammonia production using Haber-Bosch processes require high pressure and temperature, which is energy intensive. In addition, approximately 1.9 tons of carbon dioxide is released per ton of ammonia produced, because fossil fuels are used as the energy source in the ammonia industry. Meanwhile, renewable energy sources like solar and wind have significantly penetrated into the energy market in the past decade. During off-peak times, a large portion of this renewable energy cannot be utilized and an economically viable technology has to be used to store this surplus, “stranded” energy. The strong need to store off-peak renewable energy provides an unprecedented opportunity to utilize electrochemically synthesized ammonia as a means of accumulating hydrogen equivalents and stranded energy. Our work aims to design and implement advanced components (e.g. catalyst and membrane) to transform electrochemical synthesis of ammonia (EAS) 1-2 and to integrate this process with off-peak renewable energy. The reactants are nitrogen and water that are immediately available and abundant. Novel metal oxide and metal nitride catalysts for the nitrogen reduction reaction (NRR) have been designed and synthesized, which may boost the ammonia production rate by at least an order of magnitude; the developed catalyst can also effectively suppress competing hydrogen evolution reaction. Second, high temperature anion exchange polymer membrane and composite ceramics electrolyte have been explored to further enhance process stability and ammonia production rate; they also enable the EAS at a wide temperature range, from 80 ℃ to 350 ℃. Techno-economic analysis (TEA) of the EAS system integrated with renewable energy will be analyzed to evaluate the cost feasibility. Faradic efficiency and overall electrical efficiency in the context of capital cost and operations cost will also evaluated. Acknowledgement: ARPA-E REFUL Program under award # DE_AR000814 Reference: Marnellos, G., and M. Stoukides, “Ammonia synthesis at atmospheric pressure,” Science, 282(2), 98-100 (1998). Licht, S, Cui, B., Wang, B., Li, F-F, Lau, J., and Liu, S., “Ammonia syhthesis by N2 and steam electrolysis in molten hydroxide suspensions of nanoscale Fe2O3”, Science, 345, 637-640 (2014)

FPGA based fault-tolerant control on an interleaved DC/DC boost converter for fuel cell electric vehicle applications

In recent years, the effects of high-frequency current ripple coming from DC/DC converters on Proton Exchange Membrane Fuel Cell (PEMFC) have gained a growing interest from the international scientific community. Currently, the durability is one of the major technical challenges to PEMFC commercialization. Basing on the existing literature, the high-frequency current ripple leads up to long-term degradations on PEMFC, particularly on its lifetime. Accordingly, in order to enhance the PEMFC lifetime, new DC/DC converter topologies have been developed, such as Interleaved DC/DC Boost Converter (IBC). Despite this topology can minimize drastically the current ripple, the loss of one leg in case of power switch fault leads up to the drastic increasing of the current ripple and consequently long-term degradations on the PEMFC. In order to cope with this issue, solutions have to be developed. Within the framework of this research work, an efficient Fault-Tolerant Control (FTC) implemented on an FPGA board has been developed to solve this issue. The latter consists in changing the PWM gate control signal according to the faulty leg given by a fault detection algorithm. The obtained experimental results between a PEMFC and an IBC topology allows demonstrating the ability of the FTC to reduce drastically the current ripple in case of power switch faults.

Systematic Analysis for the Effects of Atmospheric Pollutants in Cathode Feed on the Performance of Proton Exchange Membrane Fuel Cells

This paper describes how primary contaminants in ambient air affect the performance of the cathode in fuel cell electric vehicle applications. The effect of four atmospheric pollutants (SO2, NH3, NO2, and CO) on cathode performance was investigated by air impurity injection and recovery test under load. Electrochemical analysis via polarization and electrochemical impedance spectroscopy was performed for various concentrations of contaminants during the impurity test in order to determine the origins of performance decay. The variation in cell voltage derived empirically in this study and data reported in the literature were normalized and juxtaposed to elucidate the relationship between impurity concentration and performance. Mechanisms of cathode degradation by air impurities were discussed in light of the findings.

A Novel Soft-Commutating Isolated Boost Full-Bridge ZVS-PWM DC–DC Converter for Bidirectional High Power Applications

A soft-commutating method and control scheme for an isolated boost full bridge converter is proposed in this paper to implement dual operation of the well-known soft-switching full bridge dc/dc buck converter for bidirectional high power applications. It provides a unique commutation logic to minimize a mismatch between current in the current-fed inductor and current in the leakage inductance of the transformer when commutation takes place, significantly reducing the power rating for a voltage clamping snubber and enabling use of a simple passive clamped snubber. To minimize the mismatch, the method and control scheme utilizes the resonant tank and freewheeling path in the existing full bridge inverter at the voltage-fed side to preset the current in the leakage inductance of the transformer in a resonant manner. Zero-voltage-switching is also achieved for all the switches at the voltage-fed side inverter in boost mode operation. The proposed soft-commutating method is verified through boost mode operation of a 3-kW bidirectional isolated full bridge dc/dc converter developed for fuel cell electric vehicle applications. The tested result verified the isolated boost converter can operate at an input voltage of 8.5–15V and an output voltage of 250–420V with a peak efficiency of 93% and an average efficiency of 88% at 55-kHz switching frequency with 72 $^circ$ C automotive coolant.