Hybrid vigour [hybrid electric vehicles]

In this paper, the author reports on the theory and practice behind cars powered by a combination of petrol engine and electric motor. The operating principles and future possibilities for hybrid electric vehicles are outlined     

Hybrid pioneers [hybrid electric vehicles]

In this paper, the author argues that hybrid vehicles remain a niche product for now, but they look set to change the future of the motor industry. In the longer term, this could lead to the jettisoning of the internal combustion (IC) engine and the wholesale switch to fuel cells as the primary automotive power source.     

Propulsion system design of electric and hybrid vehicles

There is a growing interest in electric and hybrid-electric vehicles due to environmental concerns. Efforts are directed toward developing an improved propulsion system for electric and hybrid-electric vehicles applications. This paper is aimed at developing the system design philosophies of electric and hybrid vehicle propulsion systems. The vehicles' dynamics are studied in an attempt to find an optimal torque-speed profile for the electric propulsion system. This study reveals that the vehicles' operational constraints, such as initial acceleration and grade, can be met with minimum power rating if the power train can be operated mostly in the constant power region. Several examples are presented to demonstrate the importance of the constant power operation. Operation of several candidate motors in the constant power region are also examined. Their behaviors are compared and conclusions are made     

Mechatronic design and control of hybrid electric vehicles

The work in this paper presents techniques for design, development, and control of hybrid electric vehicles (HEV). Toward these ends, four issues are explored. First, the development of HEV is presented. This synopsis includes a novel definition of degree of hybridization for automotive vehicles. Second, a load-leveling vehicle operation strategy is developed. In order to accomplish the strategy, a fuzzy logic controller is proposed. Fuzzy logic control is chosen because of the need for a controller for a nonlinear, multidomain, and time-varying plant with multiple uncertainties. Third, a novel technique for system integration and component sizing is presented. Fourth, the system design and control strategy is both simulated and then implemented in an actual vehicle. The controller examined in this study increased the fuel economy of a conventional full-sized vehicle from 40 to 55.7 mi/h and increased the average efficiency over the Federal Urban Driving Schedule from 23% to 35.4%. The paper concludes with a discussion of the implications of intelligent control and mechatronic systems as they apply to automobiles     

A novel thermal management for electric and hybrid vehicles

Assuring the right temperature in battery compartments of an electric or hybrid vehicle is crucial for the safe operation and the achievement of optimal performance of the batteries. This paper is about the design, fabrication, and testing of a novel system for thermal management for electric/hybrid vehicles. This system is based on Peltier-effect heat pumps. The experiment results show the applicability of this type of technology for the thermal management for this type of vehicles.     

Top 10 tech cars [hybrid electric vehicles]

A number of new hybrid electric vehicle owners have expressed their disappointment with their purchase because of poor mileage. Official ratings for fuel use, based on the outdated driving patterns of US government test, turned out to be a poor predictor for what typical buyers could expect. Still, though hybrids are hot, no single vehicle is likely to make as much of a splash this year as the revamped Prius did in 2004. The closest thing to a recurring theme in 2005 will be electronic stability control. Among concept cars, hybrid electrics are still going strong, and more of them are being built with lithium-ion batteries rather than the standard nickel-metal hydride. Lithium-ion, now used mostly in consumer electronics, offers close to twice the energy density of nickel-metal hydride. The widest lithium-ion vehicle so fat has to be the luxury-sedan concept Elica from Japan. This paper presents the top ten hybrid cars from different countries.     

Hybrids to the rescue [hybrid electric vehicles]

Whilst pure electric vehicles have floundered, hybrid electric vehicles (HEVs) have been making major gains and could soon make their mark. This article discusses the failings of pure electric vehicles and how HEVs get round the problems. The development and introduction of HEVs is briefly mentioned. The tax incentives for buying HEVs in Japan are discussed and the situation in the USA outlined.     

The state of the art of electric and hybrid vehicles

In a world where environment protection and energy conservation are growing concerns, the development of electric vehicles (EV) and hybrid electric vehicles (HEV) has taken on an accelerated pace. The dream of having commercially viable EVs and HEVs is becoming a reality. EVs and HEVs are gradually available in the market. This paper will provide an overview of the present status of electric and hybrid vehicles worldwide and their state of the art, with emphasis on the engineering philosophy and key technologies. The importance of the integration of technologies of automobile, electric motor drive, electronics, energy storage, and controls and also the importance of the integration of society strength from government, industry, research institutions, electric power utilities, and transportation authorities are addressed. The challenge of EV commercialization is discussed     

Iterative learning control of antilock braking of electric and hybrid vehicles

Hybrid electric vehicles (HEVs) use multiple sources of power for propulsion which provides great ease and flexibility to achieve advanced controllability and additional driving performance. In this paper, the electric motor in HEV and electric vehicle (EV) propulsion systems is used to achieve antilock braking performance without a conventional antilock braking system (ABS). The paper illustrates that the antilock braking of HEV can be easily achieved using iterative learning control for various road conditions. A vehicle model, a slip ratio model, and a vehicle speed observer were developed to control the antilock performance of HEV during braking. Through iterative learning process, the motor torque is optimized to keep the tire slip ratio corresponding to the peak traction coefficient during braking. Simulations were performed on a compact size vehicle to validate the proposed control method. The control algorithm proposed in this paper may also be used for the ABS control of conventional vehicles.