Hybrid Electric Vehicle (HEV)

Hybrid Electric Vehicle (HEV)

Abstract

The automobile industry is becoming increasingly more global each year. Companies from all around the world are merging with other companies to compete in the global market.

It is no accident that the most fuel efficient vehicles in some classes for the 2004 model year are hybrid-electric vehicles (HEVs). Hybrids can be configured in many different ways to achieve a variety of different objectives. They combine the best features of the internal combustion engine with an electric motor and can significantly improve fuel economy without sacrificing performance or driving range. HEVs may also be configured to provide electrical power to auxiliary loads such as power tools

There are two types of hybrid vehicle, parallel and series. In the parallel hybrid, electricity is obtained from a small Diesel generator set with an optimized constant turning system and power which allows the vehicle to travel at low speed. Additional power needed for acceleration and start-off is provided by a set of batteries which are recharged while braking and when the vehicle is stationary.

There are two alternatives in the electric vehicle design stage, designers may adapt conventional vehicles (conversion design) or specifically design a new vehicle, optimizing the integration of electrical equipment from the outset (purpose design). In the latter case, lighter materials can be used which compensating for the extra weight of the batteries and thereby improving vehicle speed and range

These alternative motors have various advantages over the standard design in terms of weight, system efficiency, power to volume ratios and torque. Developments in battery technology will facilitate the wider introduction of new designs for battery driven electric vehicles

INTRODUCTION

Any vehicle is a hybrid when it combines two or more sources of power. In fact, many people have probably owned a hybrid vehicle at some point. For example, a mo-ped (a motorized pedal bike) is a type of hybrid because it combines the power of a gasoline engine with the pedal power of its rider. Hybrid vehicles are all around us. These include Giant mining trucks, Submarines, diesel-electric buses, locomotives etc.

The gasoline-electric hybrid car is just that a cross between a gasoline-powered car and an electric car. Hybrid electric vehicles (HEVs) combine the internal combustion engine of a conventional vehicle with the battery and electric motor of an electric vehicle, resulting in twice the fuel economy of conventional vehicles. This combination offers the extended range and rapid refueling that consumers expect from a conventional vehicle, with a significant portion of the energy and environmental benefits of an electric vehicle. The practical benefits of HEVs include improved fuel economy and lower emissions compared to conventional vehicles. The inherent flexibility of HEVs will allow them to be used in a wide range of applications, from personal transportation to commercial hauling.

The flexibility in the design of hybrid vehicles comes from the ability of the control strategy to manage how much power is flowing to or from each component. There are many (often conflicting) objectives desirable for HEVs, the primary ones being:

• Maximize fuel economy
• Minimize emissions
• Minimize propulsion system cost to keep overall vehicle cost affordable to the consumer market
• Do all of the above while maintaining or improving upon acceptable performance (acceleration, range, handling, noise, etc.)

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