12-06-2013, 04:10 PM
HYBRID ELECTRIC VEHICLE
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ABSTRACT:-
A hybrid electric vehicle (HEV) is a hybrid vehicle which combines a conventional propulsion system with a rechargeable energy storage system (RESS) to achieve better fuel economy than a conventional vehicle.
Modern mass-produced HEVs prolong the charge on their batteries by capturing kinetic energy via regenerative braking, and some HEVs can use the internal combustion engine to generate electricity by spinning an electrical generator (often a motor-generator) to either recharge the battery or directly feed power to an electric motor that drives the vehicle.
HYBRID ELECTRIC VEHICLE:-
Regular HEVs most commonly use an internal combustion engine(ICE) in tandem with [[electric motor]]s to power their propulsion system. Modern mass-produced HEVs prolong the charge on their batteries by capturing "kinetic energy" via [[regenerative braking]], and some HEVs can use the combustion engine to generate electricity by spinning an [[electrical generator]] (often a [[motor-generator]]) to the fraction of the cause results to the abdomile reswult the vehicle.An HEV's engine is smaller and may be run at various speeds, providing more efficiency.
Regenerative Braking.:-
The electric motor applies resistance to the drive train causing the wheels to slow down. In return, the energy from the wheels turns the motor, which functions as a generator, converting energy normally wasted during coasting and braking into electricity, which is stored in a battery until needed by the electric motor.
Generator –
The generator is similar to an electric motor, but it acts only to produce electrical power. It is used mostly on series hybrids (see below).
Batteries –
The batteries in a hybrid car are the energy storage device for the electric motor. Unlike the gasoline in the fuel tank, which can only power the gasoline engine, the electric motor on a hybrid car can put energy into the batteries as well as draw energy from them.
Transmission –
The transmission on a hybrid car performs the same basic function as the transmission on a conventional car. Some hybrids, like the Honda Insight, have conventional transmissions. Others, like the Toyota Prius, have radically different ones, which we'll talk about later.
WORKING:-
At the centre of Toyota’s hybrid technology is the Hybrid Synergy Drive. This system makes intelligent use of a vehicle’s electric motors and gas/petrol engine to take advantage of the key attributes of the two power sources to ensure that the car operates at optimum fuel efficiency.
Hybrid-car Performance:-
The key to a hybrid car is that the gasoline engine can be much smaller than the one in a conventional car and therefore more efficient. Most cars require a relatively big engine to produce enough power to accelerate the car quickly. In a small engine, however, the efficiency can be improved by using smaller, lighter parts, by reducing the number of cylinders and by operating the engine closer to its maximum load.
The Benefits of a Hybrid Car:-
You might wonder why anyone would build such a complicated machine when most people are perfectly happy with their gasoline-powered cars. The reason is twofold: to reduce tailpipe emissions and to improve mileage. These goals are actually tightly interwoven.
Let's take the example of the California emissions standards, which dictate how much of each type of pollution a car is allowed to emit in California. The amount is usually specified in grams per mile (g/mi). For example, the low emissions vehicle (LEV) standard allows 3.4 g/mi of carbon monoxide. The key thing here is that the amount of pollution allowed does not depend on the mileage your car gets. But a car that burns twice as much gas to go a mile will generate approximately twice as much pollution. That pollution will have to be removed by the emissions control equipment on the car. So decreasing the fuel consumption of the car is one of the surest ways to decrease emissions.
CONCLUSION:
Thus by using hybrid electric vehicle we can save our earth from the hazards like green house effects global warming ,ozone deplication and pollution can be controlled hence hybrid electric vehicles are eco friendly