Intelligent Vehicle Electrical Power Supply System with Central Coordinated Protection

The current research of vehicle electrical power supply system mainly focuses on electric vehicles（EV） and hybrid electric vehicles（HEV）.The vehicle electrical power supply system used in traditional fuel vehicles is rather simple and imperfect;electrical/electronic devices（EEDs） applied in vehicles are usually directly connected with the vehicle＇s battery.With increasing numbers of EEDs being applied in traditional fuel vehicles,vehicle electrical power supply systems should be optimized and improved so that they can work more safely and more effectively.In this paper,a new vehicle electrical power supply system for traditional fuel vehicles,which accounts for all electrical/electronic devices and complex work conditions,is proposed based on a smart electrical/electronic device（SEED） system.Working as an independent intelligent electrical power supply network,the proposed system is isolated from the electrical control module and communication network,and access to the vehicle system is made through a bus interface.This results in a clean controller power supply with no electromagnetic interference.A new practical battery state of charge（So C） estimation method is also proposed to achieve more accurate So C estimation for lead-acid batteries in traditional fuel vehicles so that the intelligent power system can monitor the status of the battery for an over-current state in each power channel.Optimized protection methods are also used to ensure power supply safety.Experiments and tests on a traditional fuel vehicle are performed,and the results reveal that the battery So C is calculated quickly and sufficiently accurately for battery over-discharge protection.Over-current protection is achieved,and the entire vehicle＇s power utilization is optimized.For traditional fuel vehicles,the proposed vehicle electrical power supply system is comprehensive and has a unified system architecture,enhancing system reliability and security.

A comparative study of hybrid electric vehicle fuel consumption over diverse driving cycles

Environmental pollution and declining resources of fossil fuels in recent years,have increased demand for better fuel economy and less pollution for ground transportation.Among the alternative solutions provided by researchers in recent decades,hybrid electric vehicles consisted of an internal combustion engine and an electric motor have been considered as a promising solution in the short-term.In the present study,fuel economy characteristics of a parallel hybrid electric vehicle are investigated by using numerical simulation.The simulation methodology is based on a fast forward facing simulation model of a parallel hybrid and an internal combustion engine powertrains.The objective of this study is to present the main parameters which result in an optimum combination of hybrid powertrain components in order to obtain a better fuel economy of hybrid powertrains regarding different driven cycles and hybridization factors.Then,the fuel consumption of the parallel hybrid electric vehicles are compared considering various driven cycles and hybridization factors.The results showed that the better fuel economy of hybrid powertrains increases by decreasing average load of the test cycle and the point of the best fuel economy for a particular average load of the cycle moves towards higher hybridization factors when the average load of the test cycle is reduced.

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 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.

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.

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.

GB/T 26779-2021《燃料电池电动汽车加氢口》标准分析

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.

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.

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.

Techno-economic Analysis of Wind Curtailment/Hydrogen Production/Fuel Cell Vehicle System with High Wind Penetration in China

Wind curtailment/hydrogen production/fuel cell vehicle system(WCHPFCVS)is the use of curtailment to electrolyze water to produce hydrogen,which then provides energy for hydrogen fuel cell vehicles.In this paper,a techno-economic analysis of WCHPFCVS is proposed using the HOMER software.Large-scale wind power penetration is expected to lead to serious wind curtailment,and therefore,the hydrogen fuel cell vehicle will play an important role in future renewable energy storage,energy internet sharing,and electric transport areas.A system model of wind curtailment/hydrogen production/fuel cell vehicle is presented and analyzed using HOMER software to optimize the capacity and cost of the system.An annual revenue and profit of the system is then calculated and analyzed for energy conservation,emissions reduction,and environmental benefits.A technoeconomical evaluation of the system when cost of producing hydrogen and hydrogen load(fuel cell vehicle quantities)changes is also presented,taking into consideration the future progress of the technology and its market development.Techno-economic analysis of WCHPFCVS is shown as an effective method through a case study using actual data of curtailment from a wind farm in Jilin province in northeast China.

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.

Failure mode investigation of fuel cell for vehicle application

The durability of proton exchange membrane fuel cells （PEMFCs） has been posing a key technical challenge to commercial spread of fuel cell vehicles （FCVs）. To improve the durability, it is necessary to optimize the fuel cell system （FCS） design against failure modes. The fuel cell durability research method at FCS scale was exhibited, and the failure modes of fuel cell were experimentally investigated in this paper. It is found that the fuel cell dry operation, start/stop cycle and gas diffusion layer （GDL） flooding are typical failure modes of fuel cells. After the modifications against the failure modes, the durability of FCSs is improved to over 3000 h step by step.

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.

Predicting vehicle fuel consumption patterns using floating vehicle data

The status of energy consumption and air pollution in China is serious. It is important to analyze and predict the different fuel consumption of various types of vehicles under different influence factors. In order to fully describe the relationship between fuel consumption and the impact factors, massive amounts of floating vehicle data were used.The fuel consumption pattern and congestion pattern based on large samples of historical floating vehicle data were explored, drivers＇ information and vehicles＇ parameters from different group classification were probed, and the average velocity and average fuel consumption in the temporal dimension and spatial dimension were analyzed respectively.The fuel consumption forecasting model was established by using a Back Propagation Neural Network. Part of the sample set was used to train the forecasting model and the remaining part of the sample set was used as input to the forecasting model.

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.

Application potential of high performance steels for weight reduction and efficiency increase in commercial vehicles

The fast-growing economy and the gradually established highway system have boosted the road trans- portation for both passenger and cargo over the last decade in China. From 2000 to 2010 Chinese GDP increased by around 10.15% annually and the sales of medium and heavy trucks by around 18.87% （sales increased from 0.2 million in 2000 to 1.3 million in 2010） according to the National Bureau of Statistics of People＇s Republic of China. Today commercial vehicles consume almost the same amount of fuel as pas- senger cars in China although the number of commercial vehicles is only about one fourth of passenger cars. It is estimated that around 50% of imported fuel to China each year will be consumed by vehicle transportation. This si- tuation will worsen fuel shortage problems in the long run and at the same time it is partially responsible for the ever- worsening air pollution in China. Due to the widespread overloading in China, lightweight development in commer- cial vehicles has fallen far behind that of passenger cars with the consequences that Chinese commercial vehicles consume in average about 20% more fuel, especially the heavy trucks, compared to European models. Under these circumstances it is essential to reduce the vehicle fuel consumption and in- crease the transport efficiency. The key solution thereby is to implement lightweight design in commercial vehicles as it has been successfully practiced over the last decade in the passenger cars. This paper summarizes highlights given in presentations during the ＂International seminar on the ap- plication of high strength steels in light weight commercial vehicles＂ with the focus on the development and application of Nb alloyed high performance steels made for lightweight commercial vehicles.

Performance Improvement of a Centrifugal Compressor for the Fuel Cell Vehicle by Tip Leakage Vortex Control

Heightened interests have been laid at the preliminary design and optimization of the centrifugal compressor for the fuel cell vehicle.The centrifugal compressor for fuel cell vehicle is driven by a high-speed motor;however,the limit of the motor speed makes the flow passage of the impeller long and narrow,which leads to a serious tip leakage loss.Serious tip leakage loss deteriorates the compressor performance.In this paper,3-D numerical simulations were carried out with the aim of investigating the tip leakage loss in a prototype centrifugal compressor for a 100 kW fuel cell stack.The results revealed that the mixing loss caused by the interaction between the tip leakage vortex and the downstream tip leakage flow contributed to the major part of the tip leakage loss.The path of the tip leakage vortex almost followed the streamwise direction,while the downstream tip leakage flow exhibited strong circumferential momentum,which referred to the fact that they were nearly orthogonal.Therefore,a flow control approach,which was realized by enhancing the blade loading around the leading edge of blade tips in this paper,was proposed to decrease the interaction angle between the tip leakage vortex and the downstream tip leakage flow and then mitigate mixing loss by changing the flow direction of the tip leakage vortex.The results showed a smaller interaction angle was achieved in the optimized impeller compared with the baseline one.Meanwhile,the efficiency was also improved by 1.30%at design condition and the maximum efficiency improvement could be up to 10%at large mass flow condition of 92000 r/min.Being manufactured and tested,the optimized compressor was proved to achieve an isentropic efficiency of 75.84%at design condition.

Energy Security Planning for Hydrogen Fuel Cell Vehicles in Large-Scale Events:A Case Study of Beijing 2022 Winter Olympics

Energy security planning is fundamental to safeguarding the traffic operation in large-scale events.To guarantee the promo-tion of green,zero-carbon,and environmental-friendly hydrogen fuel cell vehicles(HFCVs)in large-scale events,a five-stage planning method is proposed considering the demand and supply potential of hydrogen energy.Specifically,to meet the requirements of the large-scale events’demand,a new calculation approach is proposed to calculate the hydrogen amount and the distribution of hydrogen stations.In addition,energy supply is guaranteed from four aspects,namely hydrogen produc-tion,hydrogen storage,hydrogen delivery,and hydrogen refueling.The emergency plan is established based on the overall support plan,which can realize multi-dimensional energy security.Furthermore,the planning method is demonstrative as it powers the Beijing 2022 Winter Olympics as the first“green”Olympic,providing both theoretical and practical evidence for the energy security planning of large-scale events.This study provides suggestions about ensuring the energy demand after the race,broadening the application scenarios,and accelerating the application of HFCVs.

Air-Side Fin Geometry of a Tube-Strip Heat Exchanger for Fuel Cell Vehicles

Fuel cell vehicles(FCVs)are facing severe heat dissipation challenges because fuel cell stacks are required to operate at a narrower temperature range and higher heat dissipation than those in the internal combustion engine.This study conducts a numerical analysis of a tube-strip heat exchanger applied in a high-performance FCV.The typical unit cell of the tube-strip heat exchanger is selected to numerically optimize the cell-level thermal performance of the heat exchanger.Effects of structural parameters and operational conditions are investigated.The optimal structure is obtained by focusing on the heat transfer rate and fan power at the air side,where the overall heat transfer rate of heat exchanger is determined by the effectiveness number of transfer unit method and the theoretical framework of volume averaging.The results show that the heat exchanger with rectangular fins exhibits a greater heat transfer rate than those with trapezoidal and triangular fins at an inlet air velocity of 4 m/s.Compared with the fin without a louver,the heat exchangers equipped with louvers parallel and vertical with the air flow achieve heat transfer rates of 33.1 and 42.8 kW,respectively,which increase by 2.0 kW(6.4%)and 11.7 kW(37.5%)in heat transfer rate.For high-power heat dissipation,the louvered heat exchanger with a fin pitch of 2 mm shows the best thermal performance given the same fan power.