Guest Editorial: Scanning the Issue

This special issue focuses on electric, hybrid and fuel cell vehicles. Almost all key issues and key technologies in electric, hybrid and fuel cell vehicles are covered, with a special focus on currently popular models of hybrid electric vehicles.     

Powering Sustainable Mobility: Roadmaps of Electric, Hybrid, and Fuel Cell Vehicles

In a world where environmental protection and energy conservation are growing concerns, the development of electric, hybrid, and fuel cell vehicles has taken on an accelerated pace. The dream of having commercially viable electric and hybrid vehicles is becoming a reality. It is important that the automobile companies have both proper technical and commercialization roadmaps hand-in-hand. The company CEOs should take the lead in drawing the technical and commercialization roadmaps. This task should not just be dedicated to the R&D departments or sales departments, since this is a major project that will have major effects on the company and society. In addition to having clear objectives, the senior management should also have holistic and creative thinking to oversee the progress of the project.     

Fuel cells for the long haul, batteries for the spurts [electricvehicles]

Until only a few years ago, when environmentalists, automakers, and other concerned parties spoke about low-emissions vehicles, they were almost always referring to electric vehicles (EVs)-cars, trucks, and buses powered by batteries of one kind or another. Today, having so far failed in their quest for a battery that could make EVs practical, they are looking more and more to hybrid electric vehicles (HEVs), which automakers had hitherto rejected as merely an interim solution. But hybrids based on a combination of electric motors and internal combustion engines are attractive for two main reasons: they require no technology breakthroughs and no new infrastructure. They work with existing batteries since they do not rely on them for primary energy storage; rather, they can obtain fuel at any service station. An alternative to HEVs is fuel cell powered vehicles. The principles of this technology and the associated hydrogen storage issues are discussed. Other alternative fuels are briefly outlined     

Special Section on Vehicular Energy-Storage Systems

The ten papers in this special section focus on state-of-the-art research and development and future trends in the modeling, design, control, and optimization of energy-storage systems for electric vehicles (EVs), hybrid electric vehicles (HEVs), fuel cell vehicles, and plug-in HEVs.     

Engineering the EV future

Continuing environmental concerns are moving electric vehicles (EV) into high gear at development facilities everywhere. The General Motors EV1 and the Ford Ranger EV are old news, the 106 Electric from PSA Peugeot-Citroen is established in France, where more than 1500 have been sold, and Toyota's Prius hybrid electric vehicle has exceeded all expectations in Japan, with plans afoot for an early introduction in the United States. In share-of-market terms, electric vehicles (EVs) are just beginning their infancy, total worldwide sales will be measured in the thousands of cars in 1998, compared with perhaps 20 million vehicles sold in all. But the big companies at long last are taking EVs seriously. The question now seems to be not whether automobiles will go electric but when. Battery, fuel cell and hybrid vehicles are briefly reviewed in this article     

Power Semiconductor Devices for Hybrid, Electric, and Fuel Cell Vehicles

Power semiconductor devices are key components in all power electronic systems, particularly in hybrid, electric, and fuel cell vehicles. This paper reviews the system requirement and latest development of power semiconductor devices including IGBTs, freewheeling diodes, and advanced power module technology in relating to electric vehicle applications. State-of-the-art silicon device technologies, their future trends, and theoretical limits are discussed. Emerging wide bandgap semiconductor devices such as SiC devices and their potential applications in electric vehicles are also reviewed     

Power Electronics and Motor Drives in Electric, Hybrid Electric, and Plug-In Hybrid Electric Vehicles

With the requirements for reducing emissions and improving fuel economy, automotive companies are developing electric, hybrid electric, and plug-in hybrid electric vehicles. Power electronics is an enabling technology for the development of these environmentally friendlier vehicles and implementing the advanced electrical architectures to meet the demands for increased electric loads. In this paper, a brief review of the current trends and future vehicle strategies and the function of power electronic subsystems are described. The requirements of power electronic components and electric motor drives for the successful development of these vehicles are also presented.     

Unified modeling of hybrid electric vehicle drivetrains

Hybridizing automotive drivetrains, or using more than one type of energy converter, is considered an important step toward very low pollutant emission and high fuel economy. The automotive industry and governments in the United States, Europe, and Japan have formed strategic initiatives with the aim of cooperating in the development of new vehicle technologies. Efforts to meet fuel economy and exhaust emission targets have initiated major advances in hybrid drivetrain system components, including: high-efficiency high-specific power electric motors and controllers; load-leveling devices such as ultracapacitors and fly-wheels; hydrogen and direct-methanol fuel cells; direct injection diesel and Otto cycle engines; and advanced batteries. The design of hybrid electric vehicles is an excellent example of the need for mechatronic system analysis and design methods. If one is to fully realize the potential of using these technologies, a complete vehicle system approach for component selection and optimization over typical driving situations is required. The control problems that arise in connection with hybrid power trains are significant and pose additional challenges to power-train control engineers. The principal aim of the paper is to propose a framework for the analysis, design, and control of optimum hybrid vehicles within the context of energy and power flow analysis. The approaches and results presented in the paper are one step toward the development of a complete toolbox for the analysis and design of hybrid vehicles     

Effects of drivetrain hybridization on fuel economy and dynamic performance of parallel hybrid electric vehicles

Hybrid electric vehicles have proved to be the most practical solution in reaching very high fuel economy as well as very low emissions. However, there is no standard solution for the optimal size or ratio of the internal combustion engine and the electric system. The optimum choice includes complex tradeoffs between the heat engine and electric propulsion system on one hand and cost, fuel economy, and performance on the other. Each component, as well as the overall system, have to be optimized to give optimal performance and durability at a low price. In this paper, we look at the effects of hybridization on fuel economy and dynamic performances of vehicles. Different hybridization levels from mild to full hybrid electric traction systems are examined. We also present the optimum level of hybridization for typical passenger cars. This study shows that low hybridization levels provide an acceptable fuel economy benefit at a low price, while the optimal level of hybridization ranges between 0.3 and 0.5, depending on the total vehicle power.     

PSIM-based modeling of automotive power systems: conventional, electric, and hybrid electric vehicles

Automotive manufacturers have been taking advantage of simulation tools for modeling and analyzing various types of vehicles, such as conventional, electric, and hybrid electric vehicles. These simulation tools are of great assistance to engineers and researchers to reduce product-development cycle time, improve the quality of the design, and simplify the analysis without costly and time-consuming experiments. In this paper, a modeling tool that has been developed to study automotive systems using the power electronics simulator (PSIM) software is presented. PSIM was originally made for simulating power electronic converters and motor drives. This user-friendly simulation package is able to simulate electric/electronic circuits; however, it has no capability for simulating the entire system of an automobile. This paper discusses the PSIM validity as an automotive simulation tool by creating module boxes for not only the electrical systems, but also the mechanical, energy-storage, and thermal systems of the vehicles. These modules include internal combustion engines, fuel converters, transmissions, torque couplers, and batteries. Once these modules are made and stored in the library, the user can make the car model either a conventional, an electric, or a hybrid vehicle at will, just by dragging and dropping onto a schematic blank page.     

一种基于Z源逆变器的燃料电池汽车变换器

在燃料电池汽车中,电能转换是一个核心问题。结合燃料电池的特性,简要说明了燃料电池汽车中现有变换器的不足。同时,为了克服传统燃料电池汽车电能变换器两级结构固有的不足,进一步提高其稳定性,提出了一种性能较高的Z源逆变器,分析了该结构的工作原理,采用了一种新型的具有直通零矢量的三相电压空间矢量调制方法,介绍了其工作特点以及直通零矢量的产生方法,进行了相关的仿真实验。仿真结果表明,该电路结构能够达到较高的性能要求,适合在燃料电池汽车上应用。     

An impedance-based approach to predict the state-of-charge for carbon-based supercapacitors

The impedance behavior of supercapacitors is not only a key issue for the parameterize modeling of the supercapacitor, but also an important factor for the design processes of an intelligent energy-management system which monitors the state of the supercapacitor and predicts its performance. In this paper, a simple equivalent circuit model and convolution algorithm based on impedance analysis were presented to assess state-of-charge, terminal voltage and charge/discharge capability of supercapacitors. Furthermore, an impedance function based on the equivalent impedance model was established to simulate the dynamic performance of a supercapacitor. The results can be used to control the reliable prediction of supercapacitors performance in electric vehicles, hybrid electric vehicles, fuel cell vehicles and classical automotive applications.     

Dynamic simulation for analysis of hybrid electric vehicle system and subsystem interactions, including power electronics

Simulation tools for hybrid electric vehicles (HEVs) can be classified into steady-state and dynamic models, according to their purpose. Tools with steady-state models are useful for system-level analysis. The information gained is helpful for assessing long-term behavior of the vehicle. Tools that utilize dynamic models give in-depth information about the short-term behavior of sublevel components. In this paper, a dynamic model of a hybrid electric vehicle that includes fuel cells, batteries, ultracapacitors, and induction machine drives is presented. Simulation results of vehicle configurations with a battery, a fuel cell-battery combination and a fuel cell-ultracapacitor combination are discussed. The focus of the model is a detailed assessment of different subsystem components, particularly component losses.     

Power electronics intensive solutions for advanced electric, hybrid electric, and fuel cell vehicular power systems

There is a clear trend in the automotive industry to use more electrical systems in order to satisfy the ever-growing vehicular load demands. Thus, it is imperative that automotive electrical power systems will obviously undergo a drastic change in the next 10-20 years. Currently, the situation in the automotive industry is such that the demands for higher fuel economy and more electric power are driving advanced vehicular power system voltages to higher levels. For example, the projected increase in total power demand is estimated to be about three to four times that of the current value. This means that the total future power demand of a typical advanced vehicle could roughly reach a value as high as 10 kW. In order to satisfy this huge vehicular load, the approach is to integrate power electronics intensive solutions within advanced vehicular power systems. In view of this fact, this paper aims at reviewing the present situation as well as projected future research and development work of advanced vehicular electrical power systems including those of electric, hybrid electric, and fuel cell vehicles (EVs, HEVs, and FCVs). The paper will first introduce the proposed power system architectures for HEVs and FCVs and will then go on to exhaustively discuss the specific applications of dc/dc and dc/ac power electronic converters in advanced automotive power systems.     

Development of a Hybrid Electric Vehicle With a Hydrogen-Fueled IC Engine

The motivation for the use of hydrogen as fuel is that it can be renewable and can reduce emissions. Hydrogen fuel cell vehicles are still likely to be more of a far-term reality because of their high manufacturing cost. A hybrid electric vehicle (HEV) with a hydrogen-fueled internal combustion (IC) engine has the potential of becoming a low-emission low-cost practical solution in the near future. This paper describes a standard sport utility vehicle (SUV) that has been converted into a hydrogen-powered HEV. The powertrain utilizes compressed gaseous hydrogen as fuel, a boosted hydrogen IC engine, an induction motor, a hydraulic transmission, regenerative braking, advanced nickel-metal hybrid batteries, and a real-time control system. Tests show that the vehicle can deliver higher fuel economy and much lower emissions than those of a traditional SUV without compromises in performance. This paper presents an overview of the prototype vehicle and emphasizes some of the unique features of this energy-saving clean environment solution     

Transportation [Technology 1998 analysis and forecast]

The safety debate has taken a new twist in both the aviation and the rail industries. High-profile aviation disasters and freight train wrecks have prompted demands for another great leap forward in safety. In both industries, new technology is playing a key role. And in the automotive field, public health will be the ultimate beneficiary if electric or hybrid electric vehicles start coming into wider use now that manufacturers have announced significant improvements in range. An enhanced ground proximity warning system for aviation, automatic train control, development of high speed trains, and electric vehicles powered by batteries and fuel cells, are discussed     

Are hybrid vehicles worth it?

In this paper, the author describes how, despite superior fuel economy and low emissions, hybrid electric vehicles (HEVs) cost too much at present to make economic sense     

Top 10 tech cars

This article gives an overview of technical advances in automobiles. It covers such diverse areas as: hybrid vehicle drive trains; white LED lighting; roll stability control; active steering control; electric vehicles; hydrogen powered vehicles; 42 V automotive electrical systems; and fuel cells.     

Energy Storage Systems for Automotive Applications

The fuel efficiency and performance of novel vehicles with electric propulsion capability are largely limited by the performance of the energy storage system (ESS). This paper reviews state-of-the-art ESSs in automotive applications. Battery technology options are considered in detail, with emphasis on methods of battery monitoring, managing, protecting, and balancing. Furthermore, other ESS candidates such as ultracapacitors, flywheels and fuel cells are also discussed. Finally, hybrid power sources are considered as a method of combining two or more energy storage devices to create a superior power source.