HYBRID VEHICLE

Hybrid vehicle

Hybrid vehicle

Introduction

A hybrid vehicle is any vehicle that utilizes a combination of an internal combustion engine running on traditional fossil fuels and a battery-powered electric motor for propulsion. The most basic and typical configuration is to simply place the electric motor in line with the main drive train, and to have the electric motor draw from battery power and aid the internal combustion engine while the vehicle is undergoing acceleration.

The act of accelerating burns more fuel than just cruising at a constant speed, so the assistance of the electric motor during acceleration acts to conserve fossil fuels. Likewise, as the vehicle undergoes deceleration, the reverse rotation of the electric motor acts to recharge the battery. The electric motor utilized more frequently if the vehicle makes frequent starts and stops; hence, hybrid vehicles tend to have better fossil fuel efficiency in urban driving conditions (Kluger, 1997).

Hybrid Technology

Current vehicles waste significant energy even beyond the low efficiency of their engines. They consume fuel even when no motive power required, as in going downhill, slowing, or stopped in traffic. Energy invested in accelerating the vehicles is lost as heat in braking. The engines consume excessive fuel because they must be large enough to provide peak power that is occasionally required.

Hybrid vehicles use electrical power to greatly reduce these losses without reducing performance. They are more expensive to produce than conventional vehicles; in the United States, the expense is justified by reduced fuel cost, while in Europe, where vehicles are typically driven less, small cars with efficient diesel engines are generally preferred. In hybrid vehicles currently available, all of the power driving the wheels comes eventually from an internal combustion engine. There are two basic designs: series hybrids and parallel hybrids. Both rely on internal combustion engines, electric motors, and batteries to smooth out the power requirements.

In the series arrangement, a gasoline or diesel engine runs a generator that in turn charges batteries and powers electric motors at the wheels. All of the motive power for the wheels comes from the electric motors. For peak loads, the motors call on both the generator and the batteries, so that more power is available than could be obtained from the engine alone. There are losses in converting from mechanical power at the engine to electrical power at the generator and back to mechanical power at the wheels. Many diesel railroad locomotives use this scheme, though without the battery supplement. No series hybrid automobiles are currently manufactured (Koppel, 1999).

Advantage

Hybrids are a makeshift technology between gasoline-powered and electrically powered vehicles. The best-known conception is the proposed Chevrolet Volt, a series hybrid with large batteries that can be charged either from an external electrical power source or from a small gasoline engine on board. The series design makes sense because the electric motor must be powerful enough to power the Volt unassisted. Promised range on battery power is about 40 miles, the power in one gallon of gasoline; since the great majority of trips in the ...