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The thermal management of the batteries in electrical and hybrid vehicles is a major concern for operation safety, battery life, and performance. In the current research, the temperature of the battery is tracked for 10,000 s of operation while using a Ranque–Hilsch vortex tube (RHVT) for the thermal management of the battery. An analytical model is developed and validated to study the impact of the heat generated per unit volume from the battery, the mass ratio for the cold air at the outlet to the total air at the inlet (x), entered air pressure, temperature, and mass flow rate. The peak temperature of the battery can be reduced by increasing the pressure and mass flow rate of the air at the inlet, decreasing the temperature of the air at the inlet, and using four RHVTs instead of a single RHVT. The proposed system significantly decreased the maximum temperature of the battery to 48.12 °C, compared to the battery thermal management method of using direct air, which resulted in a temperature of 75.73 °C. Furthermore, employing four RHVTs to cool the battery further reduced the maximum temperature from 48.12 to 11.23 °C, demonstrating a substantial improvement compared to utilizing a single RHVT. Utilizing the RHVT provides a good solution for the battery thermal management problem because it is cheap, small, and reduces the temperature of the air rapidly. [ABSTRACT FROM AUTHOR]

A revolution is underway in transportation, with a variety of electric vehicles rapidly coming to the fore. The switch from internal combustion engines to electric motors will change the world in many ways and is expected to help reduce the world’s carbon dioxide emissions. Inspired by this vision, leaders in China, France, and Britain have all proclaimed that they will effectively ban cars that aren’t electric by about 2040, while Volvo says all of its vehicles will be powered by electric motors in a few years. Other automakers have also announced that they are headed that way. But how far along is this revolution really? What challenges still need to be overcome to gain truly widespread acceptance on a scale that can combat climate change? Will the costs and the benefits of these new vehicles be equally spread among countries and companies? And while we all benefit in the long term, who will be the winners and the losers in our short-term world where Wall Street thinking predominates? [ABSTRACT FROM PUBLISHER]

Abstract: This paper presents the modeling and supervisory energy management design of a hybrid fuel cell/battery-powered passenger bus. With growing concerns about petroleum usage and greenhouse gas emissions in the transportation sector, finding alternative methods for vehicle propulsion is necessary. Proton Exchange Membrane (PEM) fuel cell systems are viable possibilities for energy converters due to their high efficiencies and zero emissions. It has been shown that the benefits of PEM fuel cell systems can be greatly improved through hybridization. In this work, the challenge of developing an on-board energy management strategy with near-optimal performance is addressed by a two-step process. First, an optimal control based on Pontryagin's Minimum Principle (PMP) is implemented to find the global optimal solution which minimizes fuel consumption, for different drive cycles, with and without grade. The optimal solutions are analyzed in order to aid in development of a practical controller suitable for on-board implementation, in the form of an Auto-Regressive Moving Average (ARMA) regulator. Simulation results show that the ARMA controller is capable of achieving fuel economy within 3% of the PMP controller while being able to limit the transient demand on the fuel cell system. [Copyright &y& Elsevier]

Nearly ten years have passed since the comeback of battery electric vehicles (BEVs). However, the percentage of such vehicles on the roads is still low and there is widespread concern about the long-term success of this technology. On the other hand, vehicles fueled with hydrogen, which it is beginning to be praised by several car companies as the fuel of future, do not yet have broad market acceptance, being even lower than battery electric vehicles and facing significant barriers for a widespread diffusion. In this research work, a novel type-approval test procedure is developed aiming to stablish an impartial simulation-based comparative analysis of technical feasibility, performance, range, and greenhouse gas emissions of two hybrid powertrains that manage electricity stored in a lithium-ion battery and hydrogen in tanks: Plug-In Fuel Cell Hybrid Electric Vehicle (FC-PHEV) and Extended Range Fuel Cell Hybrid Electric Vehicle (FC-EREV). The simulation framework developed considers the barriers and how to avoid them through the implementation of a set of fuel management rules. The findings indicate that hybrid powertrains achieve greater ranges and lower greenhouse gas emissions, opening the door to introduce these vehicles onto the market without the need to wait till the main barrier, the hydrogen refuelling infrastructure, is fully developed. [Display omitted] • Current situation on battery electric and fuel cell vehicles are analyzed. • The develop of hybrid powertrains with battery and hydrogen is justified. • Two powertrains for hydrogen-electricity hybrids are presented. A set of fuel management rules is designed. • A new type-approval test procedure is developed to measure consumption and emissions of hidrogen hybrids. • Extensive simulation campaign is conducted, which shows positive results about the viability of the proposed hybrid powertrains. [ABSTRACT FROM AUTHOR]

This paper focuses on ultracapacitors (electrochemical capacitors) as energy storage in vehicle applications and thus evaluates the present state-of-the-art of ultracapacitor technologies and their suitability for use in electric and hybrid drivelines of various types of vehicles. A key consideration in determining the applicability of ultracapacitors for a particular vehicle application is the proper assessment of the energy storage and power requirements. For hybrid–electric vehicles, the key issues are the useable energy requirement and the maximum pulse power at high efficiency. For a Prius size vehicle, if the useable energy storage is about 125 Wh and needed efficiency is 90–95%, analysis shown in this paper indicate that vehicles can be designed using carbon ultracapacitors (both carbon/carbon and hybrid carbon) that yield high fuel economy improvements for all driving cycles and the cost of the ultracapacitors can be competitive with lithium-ion batteries for high volume production and carbon prices of less than $20 kg-1. The use of carbon/carbon devices in micro-hybrids is particularly attractive for a control strategy (sawtooth) that permits engine operation near its maximum efficiency using only a 6 kW electric motor. Vehicle projects in transit buses and passenger cars have shown that ultracapacitors have functioned as expected and significant fuel economy improvements have been achieved that are higher than would have been possible using batteries because of the higher round-trip efficiencies of the ultracapacitors. Ultracapacitors have particular advantages for use in fuel cell powered vehicles in which it is likely they can be used without interface electronics. Development of hybrid carbon devices is continuing showing energy densities of 12 Wh kg-1 and a high efficiency power density of about 1000 W kg-1. Vehicle simulations using those devices have shown that increased power capability in such devices is needed before full advantage can be taken of their increased energy density compared with carbon/carbon devices in some vehicle applications. Energy storage system considerations indicate that combinations of ultracapacitors and advanced batteries (Wh kg-1>200) are likely to prove advantageous in the future as such batteries are developed. This is likely to be the case in plug-in hybrids with high-power electric motors for which it may be difficult to limit the size and weight of the energy storage unit even using advanced batteries. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Comprehensive evaluation of greenhouse gas emission reductions from alternative vehicle powertrains requires the use of a life cycle assessment methodology, which considers manufacturing, utilization and end-of-life phases of the vehicle and fuel production. However, vehicle powertrain technologies and regional electricity and fuel production characteristics are evolving rapidly, making such studies performed using current data obsolete in few years. For example, regional electricity generation mixes across the Canadian provinces are largely different, and they are likely to evolve with the introduction of renewable electricity. Hence, there is a general need for adaptable and flexible life cycle assessment frameworks for the transportation sector for rapid evaluation of GHG reductions using up-to-date data. The objective of this study is to develop an adaptive life cycle assessment framework for light duty vehicles that can incorporate critical new developments in vehicle powertrain technologies and changes in electricity and fuel supply. Conventional, hybrid, plug-in hybrid, battery electric and fuel cell powertrain types are included in the framework as parametrized models. Critical parameters related to vehicle size and battery capacity, fuel consumption, mileage, battery chemistry, vehicle hybridization, and electricity and fuel emission intensity are incorporated. The framework was demonstrated by applying it in the Canadian context with the analysis of scenarios associated with electricity grid emission intensity, mileage, battery capacity and battery chemistry. [ABSTRACT FROM AUTHOR]

Abstract: CNR-ITAE is involved in projects related to hybrid electric fuel cell vehicles, in which different powertrain configurations (from FC full powertrain to range extender) have been evaluated, in terms of the energy flows and system components size. The principal aim is to develop fuel cell–battery hybrid powertrains to be used in vehicles designed for some niche markets. A traction battery pack, a starting battery pack, a fuel cell power module and the combination of a parallel fuel cell–battery hybrid system have been tested. In this latter configuration, the fuel cell is used as main power source for the powertrain, also providing battery charge. The battery has the role to provide peak power during the starts of the vehicle. The hybrid powertrain has shown a fast response even at extreme and impulsive loads and a wider range compared to a battery vehicle, without compromising the weight limitations on the vehicles. [Copyright &y& Elsevier]

Abstract: Reducing or eliminating the dependency on petroleum of transportation systems is a major element of US energy research activities. Batteries are a key enabling technology for the development of clean, fuel-efficient vehicles and are key to making today''s hybrid electric vehicles a success. Fuel cells are the key enabling technology for a future hydrogen economy and have the potential to revolutionize the way we power our nations, offering cleaner, more efficient alternatives to today''s technology. Additionally fuel cells are significantly more energy efficient than combustion-based power generation technologies. Fuel cells are projected to have energy efficiency twice that of internal combustion engines. However before fuel cells can realize their potential, significant challenges remain. The two most important are cost and durability for both automotive and stationary applications. Recent electrocatalyst developments have shown that Pt alloy catalysts have increased activity and greater durability than Pt catalysts. The durability of conventional fluorocarbon membranes is improving, and hydrocarbon-based membranes have also shown promise of equaling the performance of fluorocarbon membranes at lower cost. Recent announcements have also provided indications that fuel cells can start from freezing conditions without significant deterioration. Hydrogen storage systems for vehicles are inadequate to meet customer driving range expectations (>300miles or 500km) without intrusion into vehicle cargo or passenger space. The United States Department of Energy has established three centers of Excellence for hydrogen storage materials development. The centers are focused on complex metal hydrides that can be regenerated onboard a vehicle, chemical hydrides that require off-board reprocessing, and carbon-based storage materials. Recent developments have shown progress toward the 2010 DOE targets. In addition DOE has established an independent storage material testing center to verify storage capacity of promising materials. These developments point to a viable path to achieving the DOE/FreedomCAR cost and performance goals. The transition to hydrogen-powered fuel cell vehicles will occur over the next 10–15 years. In the interim, fossil fuel consumption will be reduced by increased penetration of battery/gasoline hybrid cars. [Copyright &y& Elsevier]

Abstract: The potential improvement in fuel economy of a mid-size fuel-cell vehicle by combining it with an energy storage system has been assessed. An energy management strategy is developed and used to operate the direct hydrogen, pressurized fuel-cell system in a load-following mode and the energy storage system in a charge-sustaining mode. The strategy places highest priority on maintaining the energy storage system in a state where it can supply unanticipated boost power when the fuel-cell system alone cannot meet the power demand. It is found that downsizing a fuel-cell system decreases its efficiency on a drive cycle which is compensated by partial regenerative capture of braking energy. On a highway cycle with limited braking energy the increase in fuel economy with hybridization is small but on the stop-and-go urban cycle the fuel economy can improve by 27%. On the combined highway and urban drive cycles the fuel economy of the fuel-cell vehicle is estimated to increase by up to 15% by hybridizing it with an energy storage system. [Copyright &y& Elsevier]

Abstract: This paper describes a modelling and dynamic control design process applicable to the development of fuel cell electric vehicles (FCEVs) and hybrid electric vehicles (HEVs). After an introduction to advanced propulsion technologies the development of FCEV at DaimlerChrysler is described, followed by a discussion on hydrogen as a fuel for FCEV and the challenges related to hydrogen storage. It is essential for advanced vehicles to obtain a range comparable to that of mass production vehicles sold today. Thus, there is a strong need to operate such vehicles with high efficiency and maximize the energy stored onboard a vehicle. A stochastic dynamic programming algorithm was developed and applied to the energy management of this FCEV, which allow fuel economy optimisation while keeping a good driveability. [Copyright &y& Elsevier]

This paper deals with power flow management within a hybrid fuel cell-powered vehicle during real-time operation. The aim is the real-time control of the power distribution between the fuel cell and its associated energy storage to optimize the global hydrogen consumption while maintaining drivability. An original concept to convert the electrical power flow into equivalent hydrogen cost is proposed. On that basis, the previously developed control strategy (the equivalent consumption minimization strategy) is used to determine the real-time optimal power distribution by simple minimization of a univariate form. The approach presented has been applied to and implemented on a real fuel cell-supercapacitor-powered vehicle. Experimental and simulation results are presented, demonstrating that this approach provides an improvement of fuel efficiency along with robustness and ease of implementation. [Copyright &y& Elsevier]

Pure electric and hybrid vehicles have differing demands on the battery system of a vehicle. This results in correspondingly different demands on the battery management of a hybrid vehicle. Examples show the differing usage patterns. The consequences for the battery cells and the battery management are discussed. The importance of good thermal management is underlined. [Copyright &y& Elsevier]

This paper proposes a method for the combined estimation of the state of charge (SOC) and state of health (SOH) of batteries in hybrid and full electric vehicles. The technique is based on a set of five artificial neural networks that are used to tackle a regression and a classification task. In the method, the estimation of the SOC relies on the identification of the ageing of the battery and the estimation of the SOH depends on the behavior of the SOC in a recursive closed-loop. The networks are designed by means of training datasets collected during the experimental characterizations conducted in a laboratory environment. The lithium battery pack adopted during the study is designed to supply and store energy in a mild hybrid electric vehicle. The validation of the estimation method is performed by using real driving profiles acquired on-board of a vehicle. The obtained accuracy of the combined SOC and SOH estimator is around 97%, in line with the industrial requirements in the automotive sector. The promising results in terms of accuracy encourage to deepen the experimental validation with a deployment on a vehicle battery management system. [ABSTRACT FROM AUTHOR]