Energy Source For Electric Vehicles Research Articles

A Nonisolated Multiinput Multioutput DC–DC Boost Converter for Electric Vehicle Applications

A new nonisolated multiinput multioutput dc-dc boost converter is proposed in this paper. This converter is applicable in hybridizing alternative energy sources in electric vehicles. In fact, by hybridization of energy sources, advantages of different sources are achievable. In this converter, the loads power can be flexibly distributed between input sources. Also, charging or discharging of energy storages by other input sources can be controlled properly. The proposed converter has several outputs with different voltage levels which makes it suitable for interfacing to multilevel inverters. Using of a multilevel inverter leads to reduction of voltage harmonics which, consequently, reduces torque ripple of electric motor in electric vehicles. Also, electric vehicles which using dc motor have at least two different dc voltage levels, one for ventilation system and cabin lightening and other for supplying electric motor. The proposed converter has just one inductor. Depending on charging and discharging states of the energy storage system (ESS), two different power operation modes are defined for the converter. In order to design the converter control system, small-signal model for each operation mode is extracted. The validity of the proposed converter and its control performance are verified by simulation and experimental results for different operation conditions.

Improved Lithium Sulfur Battery Performance through Attaching Nanosilica on the Backside of Nickel Foam

Lithium Sulfur (Li-S) battery has a theoretically high specific capacity of 1675 mAh g-1, which one of the most promising energy source for electric vehicles (EVs), hybrid electric vehicles (HEVs) and energy storage system (ESS). However, Li-S batteries have crucial problem resulting from the polysulfides dissolution which is called ‘Shuttle Effect’. This shuttle effect causes overpotential and lowers its Coulomb efficiency. Also, a loss of active material by dissolution makes capacity fading. So the prevention of the polysulfides dissolution is the main issue of sulfur batteries. To solve the polysulfides dissolution we use nanosilica material on the current collector of cathode. It is reported that nanosilica has a characteristics of absorbing polysulfides. Zhang. et. al reported that they could control the shuttle mechanism by using nanosilica on the separator. However, the polysulfides accumulated on the separator hinder Li ion transport, leading to low capacity values compared to pristine Li-S batteries. In our research, nickel foam based sulfur cathode with silica coated on backside is investigated. Silica on the backside absorbs polysulfides, eventually suppressing the shuttle effect and reducing the quantity of the polysulfides on the separator. As a result, the coulomb efficiency and the capacity of the Li-S battery has increased comparing the uncoated Li-S battery. The examination was conducted by comparing between the pristine and the silica coated sample. Cells were tested at the current densities of 0.1 C rate with limited voltage of 1.8 to 2.8V. The morphology of the samples was observed on a field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM). The structure of the samples was characterized by X-ray diffraction (XRD) spectroscopy. The result was analyzed by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV).[1] S.S.Zhang, D.T.Tran, Electrochim. Acta, 114, 296 (2013).

Design methodology of hybrid electric vehicle energy sources: Application to fuel cell vehicles

This paper presents a methodology to optimize the sizing of the energy and power components in a fuel cell electric vehicle from the driving mission (which includes driving cycles, a specified acceleration and autonomy requirements). The fuel cell and the Energy Storage System associated (battery or/and ultra capacitor) design parameters are the numbers of series and parallel branches respectively Nsi and Npi. They are set so as to minimize the objective function that includes mass, cost, fulfilling the performance requirements and respect the technological constraints of each power component through a penalty function. The methodology is based on a judicious combination of Matlab-Simulink® for the global simulation and a dedicated software tool Pro@Design®. Both are well suited to treat inverse problems for the optimization. An application for a fuel cell/battery powertrain illustrates the feasibility of the proposed methodology.

Lithium−Air Battery: Promise and Challenges

The lithium−air system captured worldwide attention in 2009 as a possible battery for electric vehicle propulsion applications. If successfully developed, this battery could provide an energy source for electric vehicles rivaling that of gasoline in terms of usable energy density. However, there are numerous scientific and technical challenges that must be overcome if this alluring promise is to turn into reality. The fundamental battery chemistry during discharge is thought to be the electrochemical oxidation of lithium metal at the anode and reduction of oxygen from air at the cathode. With aprotic electrolytes, as used in Li-ion batteries, there is some evidence that the process can be reversed by applying an external potential, i.e., that such a battery can be electrically recharged. This paper summarizes the authors’ view of the promise and challenges facing development of practical Li−air batteries and the current understanding of its chemistry. However, it must be appreciated that this perspective ...

Development of a new type of electric off-road vehicle powered by microwaves transmitted through air

Needless to say, we are now facing a critical state in the global environment, i.e. global warming. We have to change our way of thinking and our economic systems from those dependent on fossil resources to those dependent on renewable energy resources, such as solar energy. In our field of research, electric vehicles are considered the best choice for reducing carbon dioxide emissions. A battery is not an adequate energy source for electric vehicles, because batteries quickly get depleted because of its low energy and power density. A fuel cell is a more favorable alternative to the battery; however, it has large mass and can only replace the internal combustion engine, but the power transmission mechanisms are still necessary. The new concept of an electric off-road vehicle proposed here is entirely different from those mentioned above. The vehicle has neither a combustion engine nor a battery but only electric motors. Energy to drive the motors is transmitted through air as microwaves at 2.45 GHz. This technology was developed at the Research Institute for Sustainable Humanosphere, Kyoto University, as a method for transmitting electricity from a large-scale solar power station (SPS) orbiting in space to the Earth. We have constructed some models of electric off-road vehicles and investigated their adoptability to microwave power transmission. In this paper, some experimental results on the use of microwave power transmission for powering the vehicles are presented, and some problems such as low energy transmission efficiency are also discussed.

Hybridization of energy sources in electric vehicles

Hybridization of energy sources in electric vehicles

Development of Polymer Electrolyte Fuel Cell Cogeneration Systems for Residential Applications

From the viewpoint of environmental protection, the polymer electrolyte fuel cell (PEFC) cogeneration system, which contributes to the reduction of CO2 and NOx emission, is drawing attention as the next-generation residential power source. In recent years, automobile manufacturers have been energetically developing PEFC as the energy source of electric vehicles on account of its good start-up performance due to a relatively low operating temperature and its high power density [1‐3]. PEFC is also promising for residential cogeneration systems when combined with a small-scale natural gas fuel processor [4]. In this review, the current status of the development of PEFC cogeneration systems for residential use including the fuel processor is reported.

Hybridization of energy sources in electric vehicles

At the present status of electric vehicle (EV) technologies, none of the available energy sources can solely fulfill all the demands of EVs to enable them to compete with gasoline powered vehicles. In this paper, an energy management system, adopting the so-called hybridization of energy sources, is proposed to coordinate multiple energy sources for EVs. Hence, the unique advantages of various EV energy sources can be fully utilized, leading to optimized fuel economy while fulfilling the expected driving range and maintaining other EV performances. The proposed optimization is performed by tuning two ratios, namely the mass ratio and the hybridization ratio.

Energy and environmental costs for electric vehicles using CO 2-neutral electricity in Sweden

Electric vehicles (EVs) may provide an alternative for CO 2-neutral transportation services. This article analyses the cost of energy and emissions from using electricity produced from Swedish renewable energy sources in electric vehicles, and compares it with the cost of an alternative in which biomass-based methanol is used in internal combustion engine vehicles (ICEVs). These costs do not include vehicle and battery costs. Cost estimates of electricity, calculated using a marginal cost perspective, include production costs as well as the cost of distribution and vehicle recharging. The energy cost per km for vehicles using electricity is calculated to be 30–70% of the cost of biomass-based methanol, depending on the general level of electricity demand, the need for grid upgrading, and the assumed cost of biomass-based methanol. A high general electricity demand in society would require expensive condensing plants to supply the vehicles, whereas with a lower demand, cheaper cogeneration and wind power plants could be utilised. An electric vehicle, used as the average Swedish car, would, during its lifetime, have energy and environmental costs 30 000–40 000 SEK ($4000–5400) lower than the current state-of-the art ICEVs using biomass-based methanol. An electric vehicle used mainly in the city centre might have energy and environmental costs which are 130 000–140 000 SEK ($17 000–19 000) lower than a current methanol-fuelled car. With future improvements in the energy efficiency and environmental performance of ICEVs the difference will be significantly reduced. If battery costs were included in the cost calculations, EVs would not be cost competitive with future ICEVs, even if battery costs are reduced to $100/kWh.

00/00453 An overview of energy sources for electric vehicles

00/00453 An overview of energy sources for electric vehicles

An overview of energy sources for electric vehicles

With ever increasing concerns on energy efficiency, energy diversification and environmental protection, electric vehicles (EVs) have launched a revenge for road transportation. Among those multidisciplinary EV technologies, energy sources are the key technology for possible commercialization and popularization of EVs. This paper not only reviews the current status of EV energy sources, but also assesses their suitability and potentiality. Moreover, the concept of multiple energy sources for EVs is identified, hence the corresponding near term and long term measures are discussed.

Study of the softening of the positive active-mass in valve-regulated lead-acid batteries for electric-vehicle applications

Abstract Valve-regulated lead-acid (VRLA) batteries have been proposed as energy sources for electric vehicles because of their good power performance and low price. Unfortunately, however, intensive utilization of the positive active-mass causes softening of this material and, thereby, reduces battery cycle-life. Experimental cells have been developed and used in order to understand the mechanism of softening. The evolution kinetics of the β-PbO 2 has been studied with very dynamic discharge profiles: different steps of the β-PbO 2 life have been explored. The experimental results have been compared and correlated with positive active-material used in electric vehicles (field tests). Scanning electron microscopy reveals a continuous growth of the β-PbO 2 microstructure throughout the cycle-life of the active mass (from ∼1 to ∼2 μm). This is confirmed by a decrease in the specific surface area (from 4 to 2.5 m 2 g −1 ). Powder X-ray diffraction reveals similar changes in the nanostructure (from ∼20 to 90 nm): the crystallites, as microstructure particles, grow with the number of cycles. These results also show the difference between the active material bound to the electrode and the β-PbO 2 crystallites which have lost contact with the plate; the latter are larger than the former (∼100 nm vs. ∼80 nm). The investigations confirm that the capacity loss of VRLA batteries is strongly linked to a micro- and nano-textural evolution of the β-PbO 2 . This finding supports the theory that there is a progressive expansion of the positive active-material, which leads to a decrease in the contact zones until final shedding of the material takes place. Strategies to overcome this effect have been tested and it appears that electrolyte additives and electrical treatments could be useful in extending battery cycle-life.

The lead-acid battery—Demonstrating the systems design approach to a practical electric vehicle power source

Resurgent interest in electric vehicles has resulted in extensive research and development programs, including government support, to develop a lead-acid battery system which can deliver acceptable range and cycle life. In the last decade, significant gains in energy density, power density, and cycle life have been made. The Improved State of the Art (ISOA) Electric Vehicle (EV) battery developed by the Globe Battery Division of Johnson Controls, Inc., utilizes the leading edge technology responsible for these improvements. The patented electrolyte circulation system is the cornerstone of this design. Emphasis was placed on a systems design approach which included priority consideration for safety and ease of maintenance. Efforts toward achieving the ambitious "Advanced Battery" goals are progressing. Rival exotic energy storage systems require considerable additional development before they might become practical alternatives. The major advantages of the lead-acid system firmly position it as the most practical energy source for electric vehicles, both now and in the near future.