Tpp on hybrid to rait

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B.V.C.O.E MECHANICAL ENGINEERING

SR.NO TOPIC PAGE NO.

1. ABSTRACT

2 INTRODUCTION

3. HOW DOES HYBRID WORKS

4. ADVANTAGES

5. DISADVANTAGES

6. RECENT TREND

7. CHALLENGES TODAY

8. CONCLUSION

ABSTRACTTPP on HYBRID PAGE NO Prepared by:-

ADIL AKHTAR KHAN

AMAR.K. BHOR

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This technical paper presentation has the detailed summary of various possible

method of using different fuel for Automobile thus called as HYBRID ELECTRIC

VEHICLE(HEV).

The report contains various aspects, basic ideas on the operation of the hybrids and

trends in Automobile industries are also shown how efficient is the new methods. All

the main topic required forHYBDIRhave also been explained in detail.

This article will focus on fuel economy analysis of HEVs and discuss highly

efficient advanced systems of HEVs in the future. It also holds the mathematical

formula, comparison chart of power output, application and various latest trend in this

method and future challenges today for this HYBRID

I sincerely hope that all my efforts put forward recording this technical paper

presentation being useful to all fellow students in future to guide them in an extreamly

latest trend in automobile field, occupy by other field operation.

Contact Detail :- Adil Akhtar Khan

Phone :- 9869871667.

Email :- [email protected]

HYBRID ELECTRIC VEHICLE

TPP on HYBRID PAGE NO Prepared by:-

ADIL AKHTAR KHAN

AMAR.K. BHOR


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Introduction

Automobiles that combine two or more types of engines are called as hybrids. A

typical hybrid is an electric motor with batteries that are recharged by a generator run

by a small gas or diesel powered cycle. Basic ideas on the operation of the hybrids

were discussed related to energy saving. Currently, vehicles are equipped with

engines that function with 30-40% of thermal efficiency. Because hybrid electric

vehicle (HEV) runs on I.C Engine as well as an electric motor; they make less

pollution and save fuel, they are expected to become more commonplace despite the

added complexity. Current (HEVs) give about 80-97 km per litre. Demand for

alternative energy, energy efficiency, reduction in CO2 emissions, has lead to the

development and commercialization of the HEVs. The article will therefore focus on

fuel economy analysis of HEVs and discuss highly efficient advanced systems of

HEVs in the future.

How does a Hybrid work?

In a traditional hybrid vehicle, it includes an electric motor to provide all of the power

to the wheels, as well as batteries to supply the motor with electricity. HEVs have a

completely separate gasoline engine powering a generator. The purpose for this


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engine is to provide enough power for the car at its cruising speed. During times of

acceleration, the battery provides the extra necessary power. When the car is

decelerating or standing still, the batteries recharge. The motor of an electric car

harnesses the batteries electrical energy by converting it to kinetic energy. The driver

simply switches on the power, selects Forward or Reverse with another switch

and steps on the accelerator pedal.

While the Internal Combustion engine of a conventional car has many moving

parts and must convert the linear motion of the pistons into rotary motion of the

wheels, an electric motor only has a single rotating element. Like a gasoline powered

car, an electric car has a system (called a power train) of gears and shafts that

transmits motion from the motor to the car wheels. Most HEVs do not have clutches

or multispeed transmissions. In order to go backward, the flow of electricity through

the motor is reversed, changing the rotation of the motor and causing the power train

to make the wheels rotate in other direction.

The earliest examples of HEVs , such as the Honda Insight and the Toyota

Prius used electric motors to supplement engines that are smaller and more fuel

efficient than they would be if they had provided all the power alone. These cars using

both gasoline and electricity require more complicated transmissions and other

systems that add weight. Some systems even use the gasoline engine to drive the rear

wheels and electric power at the front wheels for a form of four wheel drive.

Advantages

The best way to understand the advantages of a hybrid vehicle is to think about a car

traveling down a highway at a posted speed on a level ground. In this case the engine

is doing three operations:-

1. It is overcoming rolling resistance in the drive train.

2. It is overcoming air resistance.

3. It is powering accessories like the alternator, the power steering pump and the

air conditioner.


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The engine might need to produce no more than 10-20 HP to carry this load. The

reason why cars have 100-200 HP engines is to handling acceleration from a standing

stop, as well for passing and hill climbing. We only use the maximum HP rating for

1% of our driving time. The rest of the time, we are carrying around the weight and

friction of the much larger engine, which wastes a lot of energy. The purpose of this

small efficient engine is to provide enough power for the car at cruising speeds.

During times of acceleration, the battery provides the extra power necessary. The

advantage is that the small efficient gasoline engine gives great mileage.

Recover energy and store in the battery

Whenever we step on the brakes in the car, we are removing energy from the car. The

fast a car is going, the more kinetic energy it has. The brakes of the car remove this

energy and dissipate in the form of heat. A hybrid car can capture some of this energy

and store it in the battery to use later. It does this by using Regenerative Breaking

The vehicle consumes fuel to generate power to accelerate the vehicle. Deceleration

on the other hand requires air resistance, rolling resistance as well as braking. It is

only the energy accumulated by using the foot break that can be used to generate

energy. Energy could be accumulated during deceleration using electric power,

pressure, and flywheel. The graph given below shows the percentage of energy

required for acceleration. It was derived using the same vehicle that was used in fig.1,

acceleration up to 40 km/hr from a stop and decelerating at a fixed rate. The

transmission at deceleration was at neutral. The figure shows three curves atTPP on HYBRID PAGE NO Prepared by:-

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AMAR.K. BHOR


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efficiencies at 100%, 77%, and 60%.The figure also shows the percentage of

regeneration to the amount of effort required for acceleration. Thus the recovery

percentage of the amount energy required is more affected by deceleration than

acceleration. Therefore, in this mode the electric motor acts as a generator and

charges the batteries when the car is slowing down.

Analysis of fuel economy

Fuel consumption analysis on four modes of vehicle operation is to be considered.

They are as follows: - rest, acceleration, constant speed, and deceleration. The

following describes the potential for improvement in fuel efficiency by mode of

operation.

The fuel efficiency of HEVs can be estimated if motion driven energy for

electric

vehicles, power generation, charging and discharging efficiencies, and specific fuel

consumption of the power generation engine are known.

Formulae

Fuel Efficiency of HEV = motor driven energy for EV (kWh/km) x specific fuel

consumption (g/kWh) / power generation and power charging and discharging

efficiency (%)/100

Fuel Efficiency (km/l) = 1/ fuel efficiency (g/km) x density (kg/l)/1000

Fig. 6 compares the fuel economy of HEVs and gasoline vehicles. The fuel economy

of HEVs running in 10-15 mode driving cycle was derived by setting the thermal

efficiency of the power generating engine at 35%.The results show that the heavier

the weight, the greater the effect achieved by introducing HEVs. As shown in the

diagram, increased efficiency in power generation, charging and discharging, as well

as thermal efficiency of the power generating engine, contribute directly to the

enhanced fuel economy of the HEVs.


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Overall effect of improved fuel economy of the hybrid system

The hybrids run at the best fuel economy in both high and low load conditions by

running it as an electric vehicle, when the efficiency is lower than the multiplied total

of the thermal efficiency, and by providing power through the internal combustion

engines in the former. The typical low load driving conditions for a vehicle engine is

idling and constant low speed running. The specific fuel consumption rate is derived

from the fuel economy derived from the flat surface and by running resistance.

Discharging efficiency of HEV is 60% when the speed is below 50km/hr. It is 77%

when the driving speed is below 80km/hr.HEVs performed slightly better then

gasoline engines, when the speed was below 20km/hr.Thus in all the scenarios HEVs

fared better than other engines.

Power output


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Instantaneous maximum power of the motor such as during acceleration is determined

by the power output of the motor, and the electric current is provided by the battery.

The sequential top speed for HEVs is determined by the balance between the output

power of the engine generator and the traction power required for running resistance.

The basic concept of the HEVs is to run the power generating at its best thermal

efficiency i.e. 30-50% of the rated speed or 80-90% of torque, therefore output of the

same power engine running at best thermal efficiency would be 25-45%.Therefore

this would not lead to drastic downsizing of the engine when driving at the lowest fuel

economy.

Disadvantages

Despite the advantages of more efficient energy use, Hybrid cars have not been

widely adopted. Pure HEVs are impractical with the current battery technology. It

limits the distance, it can travel before the battery is exhausted, thus affecting the fuel

economy. They also require charging stations, special equipment that can recharge the

battery quickly and efficiently. This special equipment could be installed in home

garage or in the trunk of the car. And accessories such as air conditioning or radios

drain the battery even more quickly. Another problem of the traditional hybrid car is

the weight. The car has to carry the weight of the electric motor, the generator, the

gasoline engine and the batteries.

The weakness of the battery has led to the failures of some of the pioneering HEVs

such as the Toyota Prius, which was launched in 1997.

Recent trends

Use of advanced aerodynamics to reduce drag

Engine performs most of the work to push the car through the air. This force is known

as aerodynamic drag. This drag force can be reduced in a variety of ways. One of the

ways is to reduce the frontal area of the car.


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Use of low rolling resistance tires

The tires on most of the cars are optimized to give a smooth ride, minimizing noise,

and to provide good traction. But they are rarely optimized for better efficiency.

HEVs use special tires which are stiffer and inflated to a higher pressure than

conventional tires. The result is that they cause about half of the drag of the regular

tires.

Use of lightweight materials

Reducing the overall weight of the car is one easy way of increasing the mileage. A

lighter vehicle gives better fuel consumption. Composite materials such as Carbon

fiber or lightweight materials such as aluminum and magnesium can be used to reduce

the weight.

Fuel Cell technology

These HEVs represent an interim step, taking advantage of clean electric power, but

also of proven internal combustion technology. A fuel cell is a specialized form of

battery that combines hydrogen with oxygen in a chemical reaction that produces

electricity and water vapour. A fuel cell does not run down or require charging; it

operates as long as fuel and an oxidizer are supplied from the outside. This is the

future of HEVs.

Challenges Today

Automakers today anticipate more government regulations designed to reduce air

pollution emission and fuel consumption. Consequently they are designing a wide

range of new technologies some experts predict that carmakers will produce large

HEVs that can transport large nos. of people on long distance trips. Engineers have

improved the efficiency of hybrid vehicles with lightweight structures, low drag

aerodynamics. As HEVs conform to the norms of the Kyoto Protocol, they surely are

the car of the future.


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AMAR.K. BHOR


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Conclusion

The Hybrid Electric Vehicle is a highly efficient system with great potential. Such

vehicles require an amalgamation of combustion engines and electric vehicle

technology, as well as hardware and software. New ideas, such as appropriatematerials in the appropriate place in power plants are expected. We hope that the

views of this paper will be of some help in selecting alternative fuels and vehicle

power systems for the next century.


ADIL AKHTAR KHAN

AMAR.K. BHOR

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