A Novel Method for the Application of the ECMS(Equivalent Consumption Minimization Strategy)to Reduce Hydrogen Consumption in Fuel Cell Hybrid Electric Vehicles

Fuel cell hybrid electric vehicles are currently being considered as ideal means to solve the energy crisis and global warming in today’s society.In this context,this paper proposes a method to solve the problem related to the dependence of the so-called optimal equivalent factor(determined in the framework of the equivalent consumption minimum strategy-ECMS)on the working conditions.The simulation results show that under typical conditions(some representative cities being considered),the proposed strategy can maintain the power balance;for different initial battery’s states of charge(SOC),after the SOC stabilizes,the fuel consumption is 5.25 L/100 km.

Interpretation of GB/T 26779-2021,Hydrogen fuel cell electric vehicles refueling receptacle

With the development of fuel cell electric vehicle industry in China,the 70-MPa hydrogen storage cylinders have been widely applied on vehicles in recent years.The revised standard,GB/T 26779-2021,Hydrogen fuel cell electric vehicle refueling receptacle,was released on March 9,2021 with added stipulations for the 70-MPa hydrogen refuelling receptacle.The main technical contents of GB/T 26779-2021 and its similarities and differences with GB/T 26779-2011 are discussed in this paper.

Theoretical On-Board Hydrogen Redox Electric Power Generator for Infinite Cruising Range Fuel Cell Vehicles

The development of hydrogen redox electric power generators for infinite cruising range electric vehicles represents a true technological breakthrough. Such systems consist of a polymer electrolyte membrane hydrogen electrolytic cell equipped with an electrostatic-induction potential-superposed water electrolytic cell that provides a stoichiometric H2-O2 fuel mixture during operation of the vehicle. This generator functions with zero power input, zero matter input and zero emission due to the so-called ＂zero power input＂ electrostatic-to-chemical energy conversion occurring in the electrolytic cell. Here, theoretical simulations were performed to verify the target performance of such generators, assuming a pair of FC （fuel cell） and electrolytic cell stacks, both of which are commercially available.

Comparison of the Mutagenicity of Exhaust Emissions From Motor Vehicles Using Leaded and Unleaded Gasoline as Fuel

While Unleaded gasoline has the advantage of eliminating lead from automobile exhaust, its potential to reduce the exhaust gas and particles, merits further examination. In the present studies,the concentrations of hydrocarbons (HC) and earbon monoxides (CO) in emissions were analyzed on Santana engine Dynamometer under a standard test cycle, and total exhaust particles were collected from engines using leaded and unleaded gasoline. It was found that unleaded gasoline reduced the emissions of CO and HC, and decreased the quantity of vehicle exhaust particulate matters by 60%.With the unlead gasoline, only 23 kinds of organic substances, adsorbed in the particles, were identified by gas chromatography/mass spectrometer (GC/MS) while 32 components were detected using the leaded gasoline. The results of in vitro Salmonella/ microsomal test and micronucleus induction assay in CHL cells indicated that both types of gasoline increased the number of histidine-independent colonies and the frequencies of micronucleus induction; no significant differellce was found in their mutagenicity.

A New Topology of a Variable Output-Voltage DC-DC Converter for Fuel Cell Vehicles

The aim of this paper is to present a new topology of a DC-DC power converter for conditioning the current and voltages behaviors of embarked energy sources used in electrical vehicles. The fuel cells in conjunction with ultra-capacitors have been chosen as the power supply. The originality of the proposed converter is to use a variable voltage of the DC bus of the vehicle. The goal is to allow a better energy management of the embedded sources onboard the vehicle by improving its energy efficiency. After presenting and explaining the topology of the converter, some simulation and experiments results are shown to highlight its different operation modes.

Analysis on carbon emission reduction intensity of fuel cell vehicles from a life-cycle perspective

The hydrogen fuel cell vehicle is rapidly developing in China for carbon reduction and neutrality.This paper evaluated the life-cycle cost and carbon emission of hydrogen energy via lots of field surveys,including hydrogen production and packing in chlor-alkali plants,transport by tube trailers,storage and refueling in hydrogen refueling stations(HRSs),and application for use in two different cities.It also conducted a comparative study for battery electric vehicles(BEVs)and internal combustion engine vehicles(ICEVs).The result indicates that hydrogen fuel cell vehicle(FCV)has the best environmental performance but the highest energy cost.However,a sufficient hydrogen supply can significantly reduce the carbon intensity and FCV energy cost of the current system.The carbon emission for FCV application has the potential to decrease by 73.1%in City A and 43.8%in City B.It only takes 11.0%–20.1%of the BEV emission and 8.2%–9.8%of the ICEV emission.The cost of FCV driving can be reduced by 39.1%in City A.Further improvement can be obtained with an economical and“greener”hydrogen production pathway.

Correlation between carbon emissions,fuel consumption of vehicles and speed limit on expressway

This paper aimed to investigate the correlation between carbon emissions,fuel consumption,and speed limit.A theoretical model was derived based on the energy conservation law,which expresses the relationship between vehicle's fuel consumption and speed.Subsequently,a total of 40 sets of fuel consumption data were collected through field tests to verify the accuracy of the theoretical model at different speeds and different road longitudinal slope combinations.The fuel consumption was then converted to carbon emissions according to the carbon emission factors specified by Intergovernmental Panel on Climate Change(IPCC).In the field experiment,two types of cars and trucks,which are most common on the expressways in China,were selected.Finally,the travel speed under different posted speed limits was obtained through the previously established model,and the carbon emission changes of different vehicle types at different limited speeds are calculated.The results show that the speed limit has a significant impact on fuel consumption and carbon emissions.When the speed limit increased from 80 to 120 km/h,average vehicle speeds increased about 21%-27%,and fuel consumption and carbon emissions increased from approximately 33%-38%.Another interesting result was that the vehicle's fuel consumption and carbon emissions are only affected by speed.The results of the study explore the effect of speed limits on carbon emissions and provide evidence for road managers to set reasonable speed limits.

Distributed Bio-Hydrogen Refueling Stations

Hydrogen fuel cell cars are now available for lease and for sale. Renewable hydrogen fuel can be produced from water via electrolysis, or from biomass via gasification. Electrolysis is power-hungry with high demand from solar or wind power. Gasification, however, can be energy self-sufficient using a recently-patented thermochemical conversion technology known as I-HPG （indirectly-heated pyrolytic gasification）. I-HPG produces a tar-free syngas from non-food woody biomass. This means the balance of plant can be small, so the overall system is economical at modest sizes. This makes it possible to produce renewable hydrogen from local agricultural residues; sufficient to create distributed refueling stations wherever there is feedstock. This work describes the specifics of a novel bio-hydrogen refueling station whereby the syngas produced has much of the hydrogen extracted with the remainder powering a generator to provide the electric power to the I-HPG system. Thus the system runs continuously. When paired with another new technology, moderate-pressure storage of hydrogen in porous silicon, there is the potential to also power the refueling operation. Such systems can be operated independently. It is even possible to design an energy self-sufficient farm where all electric power, heat, and hydrogen fuel is produced from the non-food residues of agricultural operations. No water is required, and the carbon footprint is negative, or at least neutral.

Data-driven modeling and fault diagnosis for fuel cell vehicles using deep learning

The reliability and safety of fuel cell vehicle are crucial for the daily operation. Insulation resistance serves as a crucial index of vehicle reliability, especially when fuel cells operate at high voltages. Low insulation resistance can lead to vehicle malfunctions, exposing the operator to the risk of electric shock. In this study, long-term insulation resistance data from thirteen vehicles equipped with three different types of fuel cell systems are analyzed to diagnose possible low insulation resistance issues. For this purpose, a robust locally weighted scatterplot smoothing method is utilized to filter the original data. In this research, an insulation variation model is developed using a data-driven long short-term memory neural network to identify insulation resistance value anomalies caused by deionizer failure. The results indicate that the coefficient of determination of the failure model is 99.78 %. Moreover, current model efficiently identifies insulation faults resulting from reliability issues, such as conductivity issues of cooling pipes and erosion of vehicle wiring harnesses.

Interpretation of GB/T 24549-2009 Fuel Cell Electric Vehicle—Safety Requirements

The national standard GB/T 24549—2009 Fuel Cell Electric Vehicle—Safety Requirements specifies the general safety requirements for whole vehicle and key parts of Fuel Cell Electric Vehicle (FCEV).It is of great significance for the development of FCEV in china.This paper discusses the main contents and the background of its development.

Simulation of FCV Fuel Consumption Using Stationary PEMFC

In the near future, the use of FCVs （fuel cell vehicles） is expected to help mitigate environmental problems such as exhaustion of fossil fuels and greenhouse gas emissions. Manufacturers publish an FCV＇s specific fuel consumption, but not its dynamic characteristics such as fuel consumption ratio and motor power ratio. Thus, it is difficult to reflect the dynamic characteristics of FCVs in lifecycle system evaluation. To solve this problem, we propose a fuel-consumption simulation method for FCVs using a 1.2 kW stationary PEMFC （proton exchange membrane fuel cell）. In this study, the specific fuel consumption under driving cycles such as the Japanese 10-15 and the JC08 modes are determined and compared with the FCV simulation results obtained using fuel consumption ratios derived from the stationary PEMFC. In the simulation, the specific fuel consumption was found to be 1.16 kg-H2/100-km for the base case under the Japanese 10-15 driving cycle.

Function approximation reinforcement learning of energy management with the fuzzy REINFORCE for fuel cell hybrid electric vehicles

In the paper,a novel self-learning energy management strategy(EMS)is proposed for fuel cell hybrid electric vehicles(FCHEV)to achieve the hydrogen saving and maintain the battery operation.In the EMS,it is proposed to approximate the EMS policy function with fuzzy inference system(FIS)and learn the policy parameters through policy gradient reinforcement learning(PGRL).Thus,a so-called Fuzzy REINFORCE algorithm is first proposed and studied for EMS problem in the paper.Fuzzy REINFORCE is a model-free method that the EMS agent can learn itself through interactions with environment,which makes it independent of model accuracy,prior knowledge,and expert experience.Meanwhile,to stabilize the training process,a fuzzy baseline function is adopted to approximate the value function based on FIS without affecting the policy gradient direction.More-over,the drawbacks of traditional reinforcement learning such as high computation burden,long convergence time,can also be overcome.The effectiveness of the proposed methods were verified by Hardware-in-Loop ex-periments.The adaptability of the proposed method to the changes of driving conditions and system states is also verified.

Machine learning modeling for fuel cell-battery hybrid power system dynamics in a Toyota Mirai 2 vehicle under various drive cycles

Electrification is considered essential for the decarbonization of mobility sector, and understanding and modeling the complex behavior of modern fuel cell-battery electric-electric hybrid power systems is challenging, especially for product development and diagnostics requiring quick turnaround and fast computation. In this study, a novel modeling approach is developed, utilizing supervised machine learning algorithms, to replicate the dynamic characteristics of the fuel cell-battery hybrid power system in a 2021 Toyota Mirai 2nd generation (Mirai 2) vehicle under various drive cycles. The entire data for this study is collected by instrumenting the Mirai vehicle with in-house data acquisition devices and tapping into the Mirai controller area network bus during chassis dynamometer tests. A multi-input - multi-output, feed-forward artificial neural network architecture is designed to predict not only the fuel cell attributes, such as average minimum cell voltage, coolant and cathode air outlet temperatures, but also the battery hybrid system attributes, including lithium-ion battery pack voltage and temperature with the help of 15 system operating parameters. Over 21,0000 data points on various drive cycles having combinations of transient and near steady-state driving conditions are collected, out of which around 15,000 points are used for training the network and 6,000 for the evaluation of the model performance. Various data filtration techniques and neural network calibration processes are explored to condition the data and understand the impact on model performance. The calibrated neural network accurately predicts the hybrid power system dynamics with an R-squared value greater than 0.98, demonstrating the potential of machine learning algorithms for system development and diagnostics.

Lightweight Design of Automobile Drive Shaft Based on the Characteristics of Low Amplitude Load Strengthening

There are two kinds of internationally recognized approaches in terms of lightweight design.One is based on fatigue accumulated damage theory to achieve better reliability by optimal structural design; another is to use high performance lightweight materials.The former method takes very few considerations on the structural strengthening effects caused by the massive small loads in service.In order to ensure safety,the design is usually conservative,but the strength potential of the component is not fully exerted.In the latter method,cost is the biggest obstacle to lightweight materials in automotive applications.For the purpose of light weighting design on a fuel cell vehicle,the new design method is applied on drive shafts.The method is based on the low amplitude load strengthening characteristics of the material,and allows the stress,corresponding to test load,to enter into the strengthened range of the material.Under this condition,the light weighting design should assure that the reliability of the shaft is not impaired,even maximizes the strength potential of machine part in order to achieve the weight reduction and eventually to reduce the cost.At last,the feasibility of the design is verified by means of strength analysis and modal analysis based on the CAD model of light weighted shaft.The design applies to the load case of half shaft in independent axle,also provides technological reference for the structural lightweight design of vehicles and other machineries.

Abating transport GHG emissions by hydrogen fuel cell vehicles： Chances for the developing world

Fuel cell vehicles, as the most promising clean vehicle technology for the future, represent the major chances for the developing world to avoid high-carbon lock-in in the transportation sector. In this paper, by taking China as an example, the unique advantages for China to deploy fuel cell vehicles are reviewed. Subsequently, this paper analyzes the greenhouse gas （GHG） emissions from 19 fuel cell vehicle utilization pathways by using the life cycle assessment approach. The results show that with the current grid mix in China, hydrogen from water electro- lysis has the highest GHG emissions, at 3.10 kgCO2/km, while by-product hydrogen from the chlor-alkali industry has the lowest level, at 0.08 kgCO2/krn. Regarding hydrogen storage and transportation, a combination of gas-hydrogen road transportation and single compression in the refueling station has the lowest GHG emissions. Regarding vehicle operation, GHG emissions from indirect methanol fuel cell are proved to be lower than those from direct hydrogen fuel cells. It is recommended that although fuel cell vehicles are promising for the developing world in reducing GHG emissions, the vehicle technology and hydrogen production issues should be well addressed to ensure the life-cycle low-carbon performance.

Rare earths (Ce, Y, Pr) modified Pd/La2O3-ZrO2-Al2O3 catalysts usedin lean-burn natural gas fueled vehicles

14%REO-2.5%LaO-33.5%ZrO-50%AlO(RE = Ce, Y, Pr) composites were prepared by a coprecipitation method. The Pd catalysts were obtained by an aqueous solution of Pd(NO)loaded on the rare earths modified composites with an initial wet impregnated method. The experiment results show that catalytic activity of the rare earths modified Pd/LaO-ZrO-AlOcatalysts is better than bare sample for methane oxidation. The structural characterization results reveal that the rare earths modified Pd catalysts increase amounts of surface active oxygen species by X-ray photoelectron spectroscopy(XPS) analysis and improve the dispersion of active component from H2-temperature programmed reduction(H2-TPR) measurement compared with bare sample. Especially,Pd/14%YO-2.5%LaO-33.5%ZrO-50%AlOsample exhibits highly active stability, it is related to the Pd particles highly dispersion,which was observed by transmission electron microscope(TEM) images.

Control and Communication Network in Hybrid Fuel Cell Vehicles

This paper describes the control and communication network in fuel cell vehicles, including both the protocol and the hardware. Based on the current protocol (ISO-11898 and SAE J1939), a new practical protocol is proposed and implemented for the control and communication network in fuel cell vehicles. To improve the re-liability of data communication and to unify the network management, a new network system based on dual-port RAM is also implemented.

Experimental Study on Hydrogen Leakage and Emission of Fuel Cell Vehicles in Confined Spaces

Hydrogen safety is one of the most important safety indicators in fuel cell vehicles(FCVs)(unlike in other types of alternative energy vehicles).This indicator in FCVs is directly related to the user’s personal safety in daily vehicle usage.This paper analyzes the safety standards of FCVs in confined spaces.A sealed test chamber and an appropriate test method are devel-oped to evaluate vehicle safety based on specific test requirements.Two FCVs are subjected to static hydrogen leakage and hydrogen emission testing performed in a confined space.The results reveal that the hydrogen concentration in the vicinity of the vehicles approximates 0.0004%which is much lower than 1%while parked for 8 h during the hydrogen leakage test.In the hydrogen emission test under operating conditions,the concentration of the hydrogen gas emitted from the vehicles exceeds 2300 ppm in the vicinity,which requires careful consideration.Based on experiment and analysis,recommendations for the hydrogen safety standards of FCVs in confined spaces are proposed.

Review of DC-DC Converter Topologies Based on Impedance Network with Wide Input Voltage Range and High Gain for Fuel Cell Vehicles

The development of fuel cell vehicles(FCVs)has a major impact on improving air quality and reducing other fossil-fuel-related problems.DC-DC boost converters with wide input voltage ranges and high gains are essential to fuel cells and DC buses in the powertrains of FCVs,helping to improve the low voltage of fuel cells and“soft”output characteristics.To build DC-DC converters with the desired performance,their topologies have been widely investigated and optimized.Aiming to obtain the optimal design of wide input range and high-gain DC-DC boost converter topologies for FCVs,a review of the research status of DC-DC boost converters based on an impedance network is presented.Additionally,an evaluation system for DC-DC topologies for FCVs is constructed,providing a reference for designing wide input range and high-gain boost converters.The evaluation system uses eight indexes to comprehensively evaluate the performance of DC-DC boost converters for FCVs.On this basis,issues about DC-DC converters for FCVs are discussed,and future research directions are proposed.The main future research directions of DC-DC converter for FCVs include utilizing a DC-DC converter to realize online monitoring of the water content in FCs and designing buck-boost DC-DC converters suitable for high-power commercial FCVs.

Advancing green energy solution with the impetus of COVID-19 pandemic

The global energy system needs a revolutionary transition from today’s fossil fuel to a low carbon energy system by having deep carbonization in all energy demand sectors.Especially in the transport sector,fossil fuel-based vehicles contribute to a more massive amount of greenhouse gas emissions(GHG),mainly carbon dioxide(CO_(2))and particulate matter(PM2.5),affecting human health,society,and the climate system.Hydrogen and fuel cell technology is a promising low carbon transition pathway that supports GHG mitigation and achieves sustainable development.Although hydrogen and fuel cells are assuring,fuel cell vehicle expensiveness and the high cost of hydrogen production with the low carbon footprint are significant hindrances for its widespread deployment.Besides the situation above,the present corona virus(COVID-19)has devastated our global economy and ramps down the future of fossil fuel.It provides opportunities to rethink and reshape our energy system to a low carbon footprint.By utilizing the situation,governments and policymakers need to eliminate fossil fuel and invest in the hydrogen and fuel cell technologies deployment as future energy systems.This review article provides a technical overview of a low carbon energy system,production,and end-use service in a hydrogen economy perspective for developing a sustainable energy future.The techno-economic analysis of the different hydrogen production routines and fuel cell vehicles and their infrastructures are primarily focused.Finally,a long-term policy alignment was outlined to advance the hydrogen energy system for post-COVID-19 in the United Nation’s(UN)sustainable development goals framework.