Physics project (Hybrid Electric Vehicle)

8/14/2019 Physics project (Hybrid Electric Vehicle)

1/26

PHYSICS PROJECT

SUBMITTED TO: Mr. IMTIAZ ALI

SUBMITTED BY:

MUHAMMAD JAWAD RAUF

ENROLLEMENT NUMBER: 01_133092_144

SAJJAD ALI

ENROLLEMENT NUMBER: 01_133092_153

BS-E:1ST SEMESTER


2/26

HYBRID ELECTRIC

VEHICLE(HEV)

CONTENTS:

1)

HISTORY OF HEV2) INTRODUCTION TO HEV

3) WORKING IN HEV

4) COMPONENTS USED IN HEV

5) ADVANTAGES OF HEV

6) DISADVANTAGES OF HEV

7) MODELS OF HEV

1) HISTORY OF HEV:


3/26

In 1901, while employed at Lohner Coach Factory, FerdinandPorsche designed the Mixte, a 4WD series-hybrid version of"System Lohner-Porsche" electric carriage previously appeared in1900 Paris Salon. The Mixte included a pair of generators drivenby 2.5-hp Daimler IC engines to extend operating range. [7][8] TheMixte broke several Austrian speed records, and also wonthe Exelberg Rally in 1901 with Porsche himself driving. The Mixteused a gasoline engine powering a generator, which in turnpowered electric hub motors, with a small battery pack forreliability. It had a range of 50 km, a top speed of 50 km/h and apower of 5.22 kW during 20 minutes.In 1905, H. Piper filed a US patent application for a hybrid vehicle.[9]

The 1915 Dual Power, made by the Woods Motor Vehicle electric

car maker, had a four-cylinderICE and an electric motor. Below15 mph (25 km/h) the electric motor alone drove the vehicle,drawing power from a battery pack, and above this speed the"main" engine cut in to take the car up to its 35 mph (55 km/h) topspeed. About 600 were made up to 1918.The first gasoline-electric hybrid car was released by the WoodsMotor Vehicle Company of Chicago in 1917. The hybrid was acommercial failure, proving to be too slow for its price, and toodifficult to service.

In 1931 Erich Gaichen invented and drove from Altenburg to Berlina 1/2 horsepower electric car containing features laterincorporated into hybrid cars. Its maximum speed was 25 milesper hour (40 km/h), but it was licensed by the Motor TransportOffice, taxed by the German Revenue Department and patentedby the German Reichs-Patent Amt. The car battery was re-charged by the motor when the car went downhill. Additionalpower to charge the battery was provided by a cylinder ofcompressed air which was re-charged by small air pumpsactivated by vibrations of the chassis and the brakes and by

igniting oxyhydrogen gas. An account of the car and hischaracterization as a "crank inventor" can be found in ArthurKoestler's autobiography, Arrow in the Blue, pages 269-271, whichsummarize a contemporaneous newspaper account written byKoestler. No production beyond the prototype was reported.

2) INTRODUCTION TO HEV:
http://en.wikipedia.org/wiki/Ferdinand_Porschehttp://en.wikipedia.org/wiki/Ferdinand_Porschehttp://en.wikipedia.org/wiki/Lohner-Porsche_Mixte_Hybridhttp://en.wikipedia.org/wiki/Hybrid_electric_vehicle#cite_note-6%23cite_note-6http://en.wikipedia.org/wiki/Hybrid_electric_vehicle#cite_note-7%23cite_note-7http://en.wikipedia.org/w/index.php?title=Exelberg_Rally&action=edit&redlink=1http://en.wikipedia.org/wiki/Internal_combustion_enginehttp://en.wikipedia.org/wiki/Electrical_generatorhttp://en.wikipedia.org/wiki/Hub_motorhttp://en.wikipedia.org/wiki/Hybrid_electric_vehicle#cite_note-Victor_Wouk_p70-74-8%23cite_note-Victor_Wouk_p70-74-8http://en.wikipedia.org/wiki/Woods_Motor_Vehiclehttp://en.wikipedia.org/wiki/Internal_combustion_enginehttp://en.wikipedia.org/wiki/Woods_Motor_Vehiclehttp://en.wikipedia.org/wiki/Woods_Motor_Vehiclehttp://en.wikipedia.org/wiki/Ferdinand_Porschehttp://en.wikipedia.org/wiki/Ferdinand_Porschehttp://en.wikipedia.org/wiki/Lohner-Porsche_Mixte_Hybridhttp://en.wikipedia.org/wiki/Hybrid_electric_vehicle#cite_note-6%23cite_note-6http://en.wikipedia.org/wiki/Hybrid_electric_vehicle#cite_note-7%23cite_note-7http://en.wikipedia.org/w/index.php?title=Exelberg_Rally&action=edit&redlink=1http://en.wikipedia.org/wiki/Internal_combustion_enginehttp://en.wikipedia.org/wiki/Electrical_generatorhttp://en.wikipedia.org/wiki/Hub_motorhttp://en.wikipedia.org/wiki/Hybrid_electric_vehicle#cite_note-Victor_Wouk_p70-74-8%23cite_note-Victor_Wouk_p70-74-8http://en.wikipedia.org/wiki/Woods_Motor_Vehiclehttp://en.wikipedia.org/wiki/Internal_combustion_enginehttp://en.wikipedia.org/wiki/Woods_Motor_Vehiclehttp://en.wikipedia.org/wiki/Woods_Motor_Vehicle


4/26

Hybrid electric vehicles (HEVs) use both electricity andhydrocarbon fuels to provide motive power, but the vehicles soleenergy source is the hydrocarbon fuel. Relative to conventionalvehicles in heavy urban traffic, HEVs can achieve around 50%better fuel economy, achieved by the regenerative braking andturning off their internal combustion engine when the vehicle isstopped or moving slowly. In open highway driving these benefitsmatter little, so a HEV will gave fuel consumption similar to anotherwise comparable conventional vehicle.Hybrid-electric vehicles come in two flavours: parallel and series.In parallel HEVs, both the internal combustion engine and electricmotors drive the wheels; usually the electric motor and internalcombustion engine drive the same transaxle. The Toyota Prius isthe familiar example.

In series HEVs, the internal combustion engine only drives agenerator, which supplies power to batteries. The wheel drivemotors are supplied only from the batteries or other onboardstorage. The GM Volt will be a series PHEV [Plug-in HybridElectric Vehicle].

A hybrid electric vehicle (HEV) combines a conventional internalcombustion engine (ICE) propulsion system withan electric propulsion system. The presence of the electric powertrain is intended to achieve either betterfuel economy than

a conventional vehicle, or better performance. A variety of types ofHEV exist, and the degree to which they function as EVs varies aswell. The most common form of HEV is the hybrid electric car,although hybrid electric trucks (pickups and tractors) also exist.Modern HEVs make use of efficiency-improving technologies suchas regenerative braking, which converts the vehicle's kineticenergy into battery-replenishing electric energy, rather thanwasting it as heat energy as conventional brakes do. Somevarieties of HEVs use their internal combustion engine to generateelectricity by spinning an electrical generator(this combination is

known as a motor-generator), to either recharge their batteries orto directly power the electric drive motors. Many HEVs reduce idleemissions by shutting down the ICE at idle and restarting it whenneeded; this is known as a start-stop system. A hybrid-electric

Produces less emissions from its ICE than a comparably-sizedgasoline car, as an HEV's gasoline engine is usually smaller than
http://www.global-greenhouse-warming.com/plug-in-hybrid.htmlhttp://www.global-greenhouse-warming.com/plug-in-hybrid.htmlhttp://en.wikipedia.org/wiki/Internal_combustion_enginehttp://en.wikipedia.org/wiki/Internal_combustion_enginehttp://en.wikipedia.org/wiki/Ground_propulsionhttp://en.wikipedia.org/wiki/Electric_powerhttp://en.wikipedia.org/wiki/Fuel_economy_in_automobileshttp://en.wikipedia.org/wiki/Conventional_vehiclehttp://en.wikipedia.org/wiki/Regenerative_brakinghttp://en.wikipedia.org/wiki/Electrical_generatorhttp://en.wikipedia.org/wiki/Motor-generatorhttp://en.wikipedia.org/wiki/Idle_reductionhttp://en.wikipedia.org/wiki/Idle_reductionhttp://en.wiktionary.org/wiki/shut_downhttp://en.wikipedia.org/wiki/Internal_combustion_enginehttp://en.wiktionary.org/wiki/idlehttp://en.wikipedia.org/wiki/Start-stop_systemhttp://en.wikipedia.org/wiki/Internal_combustion_enginehttp://www.global-greenhouse-warming.com/plug-in-hybrid.htmlhttp://www.global-greenhouse-warming.com/plug-in-hybrid.htmlhttp://en.wikipedia.org/wiki/Internal_combustion_enginehttp://en.wikipedia.org/wiki/Internal_combustion_enginehttp://en.wikipedia.org/wiki/Ground_propulsionhttp://en.wikipedia.org/wiki/Electric_powerhttp://en.wikipedia.org/wiki/Fuel_economy_in_automobileshttp://en.wikipedia.org/wiki/Conventional_vehiclehttp://en.wikipedia.org/wiki/Regenerative_brakinghttp://en.wikipedia.org/wiki/Electrical_generatorhttp://en.wikipedia.org/wiki/Motor-generatorhttp://en.wikipedia.org/wiki/Idle_reductionhttp://en.wikipedia.org/wiki/Idle_reductionhttp://en.wiktionary.org/wiki/shut_downhttp://en.wikipedia.org/wiki/Internal_combustion_enginehttp://en.wiktionary.org/wiki/idlehttp://en.wikipedia.org/wiki/Start-stop_systemhttp://en.wikipedia.org/wiki/Internal_combustion_engine


5/26

a pure fossil-fuel vehicle, and if not used to directly drive the car,can be geared to run at maximum efficiency, further improving fueleconomy.The hybrid-electric vehicle did not become widely available untilthe release of the Toyota Prius in Japan in 1997, followed bythe Honda Insight in 1999. While initially perceived asunnecessary due to the low cost of gasoline, worldwide increasesin the price of petroleum caused many automakers to releasehybrids in the late 2000s; they are now perceived as a coresegment of the automotive market of the future.[3][4] Worldwidesales of hybrid vehicles produced by Toyota reached 1.0 millionvehicles by May 31, 2007, and the 2.0 million mark was reachedby August 31, 2009, with hybrids sold in 50 countries. Worldwidesales are led by the Prius, with cumulative sales of 1.43 million by

August 2009.[1] The second-generation Honda Insight was the top-selling vehicle in Japan in April 2009, marking the first occasionthat an HEV has received the distinction. American automakershave made development of hybrid cars a top priority.
http://en.wikipedia.org/wiki/Fossil-fuel_vehiclehttp://en.wikipedia.org/wiki/Toyota_Priushttp://en.wikipedia.org/wiki/Honda_Insighthttp://en.wikipedia.org/wiki/Automakerhttp://en.wikipedia.org/wiki/Automotive_markethttp://en.wikipedia.org/wiki/Hybrid_electric_vehicle#cite_note-2%23cite_note-2http://en.wikipedia.org/wiki/Hybrid_electric_vehicle#cite_note-3%23cite_note-3http://en.wikipedia.org/wiki/Toyotahttp://en.wikipedia.org/wiki/Hybrid_electric_vehicle#cite_note-KBB1009-0%23cite_note-KBB1009-0http://en.wikipedia.org/wiki/Fossil-fuel_vehiclehttp://en.wikipedia.org/wiki/Toyota_Priushttp://en.wikipedia.org/wiki/Honda_Insighthttp://en.wikipedia.org/wiki/Automakerhttp://en.wikipedia.org/wiki/Automotive_markethttp://en.wikipedia.org/wiki/Hybrid_electric_vehicle#cite_note-2%23cite_note-2http://en.wikipedia.org/wiki/Hybrid_electric_vehicle#cite_note-3%23cite_note-3http://en.wikipedia.org/wiki/Toyotahttp://en.wikipedia.org/wiki/Hybrid_electric_vehicle#cite_note-KBB1009-0%23cite_note-KBB1009-0


6/26

3) WORKING IN HEV:

At the centre of Toyotas hybrid technology is the Hybrid SynergyDrive. This system makes intelligent use of a vehicles electricmotors and gas/petrol engine to take advantage of the keyattributes of the two power sources to ensure that the car operatesat optimum fuel efficiency.

1. At start-off/low-speeds, Hybrid Synergy Drive runs the car onthe electric motors only, since the gas/petrol engine does notperform efficiently. A gas/petrol engine cannot produce high torquein the low r.p.m. range, whereas electric motors can - delivering avery responsive and smooth start.


7/26

2. However, the gas/petrol engine is quite energy efficient forcruising. Power produced by the gas/petrol engine is used to drivethe wheels and also the generator to provide power to the electricmotors or to charge the battery. By making use of theengine/motor dual powertrain, the energy produced by thegas/petrol engine is transferred to the road surface with minimalloss.


8/26

3. Under deceleration or braking, Hybrid Synergy Drive uses thecar's kinetic energy to let the wheels turn the electric motors andrecover regenerative energy to recharge the battery. Energy that isnormally lost as friction heat under deceleration is converted intoelectrical energy, which is recovered in the battery to be reusedlater.

THE HYBRID'S ELECTRIC MOTOR:

The electric motor handles normal stop-and-go travel and initialhighway acceleration. The electric motor also assists the gas ordiesel engine to reduce fuel consumption and emissions. Forexample, it is the electric motor that drives energy-wastingaccessories like the power steering pump and air conditioner.


9/26

THE HYBRID'S GASOLINE MOTOR:

The gasoline- or diesel-powered internal combustion engine kicksin whenever the vehicle gets to higher speeds. Hybrids have asophisticated computer control system that decides when to switchfrom one power source to the other.The gas or diesel engine also can generate power for the electricmotor. At highway speeds, the gasoline engine recharges theelectric motor's battery.

THE HYBRID'S SUPER BATTERY:

The Hybrid's ultracapacitor battery feeds power to the electricmotor. The battery itself is recharged during the times that thevehicle is coasting and braking. (Therefore, Hybrids never need tobe plugged into an outside charging device.) During coasting andbraking, the electric motor switches to "generate" instead of"consume" electricity. Whenever the brake is released, the enginerestarts instantaneously. This process of switching power betweenthe two types of engines saves gas and avoids pollution.Just like the battery under the hood of your current vehicle, a

Hybrid vehicle's electric battery pack may eventually wear out andneed to be replaced. However, auto manufacturers are stating thatthe Hybrid's battery is designed to last the lifetime of the vehicle -somewhere between 150,000 and 200,000 miles. It is simply tooearly to tell.


10/26

4) COMPONENTS USED INHEV:

Essentially, an HEV combines an energy storage system, a powerunit, and a vehicle propulsion system. The primary options forenergy storage includebatteries, ultracapacitors, and flywheels.

Although batteries are by far the most common choice for energystorage, research is still being done in other energy storage areas.Hybrid power unit options are spark ignition engines, compressionignition engines, gas turbines, and fuel cells. Propulsion can comeentirely from an electric motor, such as in a series configuration, orthe engine might provide direct mechanical input to the vehicle

propulsion system in aparallel configuration system.

BATTERY MONITORING UNIT:

The battery-monitoring unit monitors the voltage, current andtemperature of the high-voltage battery.

Conventional battery-monitoring units place only low voltageelements on both sides of the circuit board. DENSO's new battery-monitoring unit places not only low voltage elements but also high

voltage elements on both sides of the circuit board. This, alongwith reducing the number of elements, enables the new battery-monitoring unit to be approximately 65 percent smaller andapproximately 50 percent lighter than conventional products.
http://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#bhttp://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#uhttp://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#fhttp://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#shttp://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#chttp://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#chttp://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#ghttp://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#fhttp://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#mhttp://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#shttp://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#phttp://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#bhttp://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#uhttp://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#fhttp://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#shttp://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#chttp://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#chttp://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#ghttp://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#fhttp://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#mhttp://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#shttp://www1.eere.energy.gov/vehiclesandfuels/resources/fcvt_glossary.html#p


11/26

The battery ECU also detects:

main battery abnormalities degree of the main battery deterioration accidental electrical connection between the high-voltage

part and the body

DENSO provides battery ECUs for nickel metal hydride batteriesas well as lithium ion batteries.

Benefits and Features:

Quick and precise voltage detectiono In 2003, DENSO developed a new voltage detection

circuit that more quickly and precisely detects voltagesthan a conventional circuit, while maintaining theinsulating property between the high-voltage and low-voltage sides in the battery ECU. Compared to aconventional circuit, DENSO achieved anapproximately 50 percent reduction in voltagedetection time and voltage detection error.

Small size and light weight

o The newly developed voltage detection circuit has asimple structure composed only of switching elementsand condensers, significantly reducing the size andweight of the battery ECU.


12/26

DC-DC Converter:

The DC-DC converter converts the main batterys high voltage(200 to 400 volts) to the auxiliary batterys lower voltage (12 volts)and charges the auxiliary battery. The DC-DC converter alsoserves as a power source for 12-volt equipment including

headlamps, windshield wipers and horns.

For its new DC-DC converter, DENSO developed a unique powerconversion circuit that reduces energy loss by half compared to aconventional DC-DC converter, decreasing the amount of heatgenerated during power conversion, and improving fuelconsumption. This enables the DC-DC converter to be cooled byair instead of the conventional method of cooling by water,allowing more flexibility in installation location.

The full-bridge circuit accommodates a wide range of inputvoltages and provides high output. DENSO has minimized sizeand weight by using high-frequency switching and low-profilemagnetic parts.

DENSO Technology Leading the World

In 2000, DENSO launched a compact DC-DC converter thatachieved the worlds largest output current 100 amperes.

Benefits and Features

High reliabilityo Adopting an isolated converter circuit.

Small size and light weight


13/26

INTEGRATED STARTER GENERATOR:

DENSOs small, long-life Integrated Starter Generator (Stop-Starttechnology) allows the engine to instantly and quietly restart afterthe idle stop. It has a life expectancy of more than 10x

conventional technology, allowing around 300,000 re-starts.

ISG Functions:

The ISG instantly and quietly restarts the vehicles engineafter the idle stop.

As a conventional alternator, the ISG produces electricpower when the vehicle is running, and supplies the electricpower to electric devices and/or charges the battery.

The ISG can help to decelerate the vehicle by generatingelectric power, which is called regenerative braking. Theelectric power generated charges the battery, reducing fuelconsumption.

If a clutch disconnects the ISG and the compressor from theengine during the idle stop, the ISG can drive the air-conditioning compressor via a belt.


14/26

CO2 AIR CONDITIONING SYSTEM:

As a leader in the field of air conditioners, DENSO has been at theforefront of environmental technology. In 2002, DENSO introducedthe worlds first carbon dioxide (CO2) air conditioning system for

Toyotas fuel cell hybrid vehicle (FCHV-4). The GWP of CO2 isextremely low about 1/1,300 of that of HFC-134a. DENSOcurrently produces the following components.

COMPRESSOR:

The compressor for the CO2 air conditioning system is unique. It isdesigned to withstand high pressure and reduce its powerconsumption to improve the coefficient of performance (COP)* ofthe system.

The compressor used for Toyotas fuel cell hybrid vehicle (FCHV-4) is a scroll type and is driven electrically rather than by an enginevia a belt. The electric compressor can be made airtight, whichmakes refrigerant leakage unlikely. In addition, since thecompressor can be controlled by a motor regardless of the enginespeed, the CO2 air conditioning system works efficiently in alldriving conditions, providing comfortable air to passengers.

COP = cooling capability/compressor consumption


15/26

GAS COOLER:

The gas cooler corresponds to a conventional condenser andcools the CO2 refrigerant discharged from the compressor at ahigh pressure.

Because of this high pressure, the tubes in which refrigerant flowsand the tank for distributing the refrigerant into the tubes of the gascooler are strengthened compared to a conventional heatexchanger. Specifically, each tube is made five to 10 timesstronger than a conventional tube by optimizing the hole diameterand wall thickness. The tank is reduced in size in order todecrease the area that receives high pressure, without losing thecapability to uniformly distribute the refrigerant into the tubes.

In addition, the gas cooler uses a unique tank structure, whichallows refrigerant to flow more efficiently in the gas cooler toexchange heat with air.

INTERNAL HEAT EXCHANGER:

The CO2 air conditioning system incorporates an internal heatexchanger that is installed between the outlet of the gas coolerand the evaporator. The internal heat exchanger, which is notequipped with the conventional HFC-134a, helps to further coolthe CO2 refrigerant by exchanging heat with refrigerant flowing atthe low-pressure side of the system. The internal heat exchangerincreases the amount of liquid refrigerant flowing into theevaporator to increase the cooling performance, resulting inincreased the coefficient of performance (COP = coolingcapability/compressor consumption) of the system.

The internal heat exchanger is integrated with the accumulatorand the expansion valve so that the structure of the CO2 airconditioning system becomes simple and easy to install.


16/26

ELECRTIC COMPRESSOR:

In 2003, DENSO launched the worlds first small, light-weightelectric compressor for hybrid electric vehicles. The electric

compressor provides comfortable air conditioning even duringidle stops (when the engine shuts down to save fuel andemissions). This maintains cabin comfort while significantlyreducing fuel consumption.

Benefits and Features:

Small size and light weighto By adopting a newly developed motor winding method,

DENSO achieves 30 percent size reduction and 53percent weight reduction of the electric compressorcompared to traditional electric compressors, providingmore space in the vehicle and further improving fuelconsumption.

o High revolution speed (7500 rotations per minute),regardless of the engine speed, reduces thedisplacement (amount of refrigerant discharged fromthe compressor per one rotation) to 18 cm3, allowingthe compressor to be more compact.

High efficiency and quiet operationo The electric compressor combines a scroll compressor

and a DC brushless motor. The optimized scroll formand advanced motor control technology improvesefficiency and reduces noise and vibration.


17/26

Quick startingo DENSOs advanced motor control technology enables

the electric compressor to start at a high revolutionspeed as soon as the air conditioning system is turnedon.

SYSTEM MAIN RELAY:

The system main relay connects anddisconnects electric currents between thehigh-voltage battery and high-voltagesystem by controlling the contact ofmovable and fixed parts. It also shuts off

the high electrical voltage in a collision tosecure the safety of vehicle occupants.

DENSO's newly developed system mainrelay reduces operation noise byapproximately 10 dB by using a structurethat lessens the impact when a movablepart comes into contact with a fixed part,without slowing the speed in shutting offthe high electrical voltage in a collision.DENSO also reduced the number ofcomponents used in the product, makingassembly easier.

BATTERY COOLING SYSTEM:


18/26

In conventional battery cooling systems, the battery blower drawsonly cabin air to cool the hybrid vehicle's main battery. DENSO'snewly developed battery cooling system can use cooled air fromthe cooling unit of the rear air conditioning system as well as cabinair to cool the main battery.

Accordingly, the new battery cooling system provides comparable

cooling performance with approximately half the amount of airrequired by previous models. This reduces noise from blowing airby approximately 30 percent, contributing to quietervehicle interiors

5) ADVANTAGES OF HEV:


19/26

Here some of the advantages of HEV.1) Hybrid Vehicles are good for the environment. They can reducesmog by 90 percent and they use far less gasoline thanconventional cars.2) Hybrid Vehicles are economical. They can get up to 55 to 60mpg in city driving, while a typical SUV might travel 15-20 milesper gallon, or use three times as much gas for the same distance!3) Hybrids are better than all-electric cars because hybrid carbatteries recharge as you drive so there is no need to plug in.

Also, most electric cars cannot go faster than 50-60 mph, whilehybrids can.4) Greater operating efficiency because HEVs use regenerativebraking, which helps to minimize energy loss and recover theenergy used to slow down or stop a vehicle;

5) Lighter engines because HEV engines can be sized toaccommodate average load, not peak load, which reduces theengine's weight;

6) Greater fuel efficiency because hybrids consume significantlyless fuel than vehicles powered by gasoline alone;

7) Cleaner operation because HEVs can run on alternative fuels(which have lower emissions), thereby decreasing ourdependency on fossil fuels (which helps ensure our nationalsecurity)8) Lighter vehicle weight overall because special lightweightmaterials are used in their manufacture.


20/26

6) DISADVANTAGES OF HEV:

Unlike the conventional cars that make use of a single source of

energy, a hybrid car runs on a combination of a battery and a fuelengine. However, these two sources are used alternatively by thecar and are not merged with each other. Hybrid cars are gainingpopularity because of their economical, social, and environmentalbenefits. But, these 'green cars' also have some disadvantageswhich should be kept in mind before considering them for apurchase.

Following are the 5 main drawbacks of a hybrid car:

1) The main shortcoming of a hybrid car that prevents it fromgaining popularity with the masses is its high cost. It has also beenestimated that the price of hybrid cars will increase over the years,inviting more troubles for the buyers. The fuel savings expected ina hybrid car are also believed to be a bit exaggerated, whencompared to the total costs of purchasing and maintaining a hybridcar.

2) Another disadvantage is that the acceleration of most hybrid

cars is not exhilarating. That is, they tend to accelerate at a slowerspeed when compared to the conventional gas-powered cars. Toput in simple words, you would not be able to achieve theanticipated speed within the same time period in a hybrid car, thanyou would in cars that are powered only by gasoline. This featureof a hybrid car will certainly make you feel unsafe while driving asyou would not be able to keep pace with the other normal cars onthe road.

3) The third disadvantage of a hybrid car is the high cost of itsbatteries. Although the battery pack comes with an extendedwarranty, it needs to be replaced on completing 80,000 miles.Depending on the model of your car, this battery pack may cost


21/26

you anything between $5,000 and $8,000. Therefore, if you are afrequent traveler, a hybrid car is definitely not a good choice foryou.

4) In order to facilitate high speeds, hybrid cars are made usinglight-weight body materials and are kept small in size. Owing totheir small size and light weight, they become more vulnerable toserious damage when involved in any accident, small or big.

5) As these cars are new and expensive, their stocks are limitedand are not available in all parts of the country. Also, there are notmany skilled hybrid car repair mechanics. So, you can imagine thekind of troubles you will have to face if you buy an expensivehybrid car from a place far away from your residence, and then,

when required, get it repaired from a local unskilled repairmechanic

Hybrid cars do have the above mentioned disadvantages, but thatdoes not mean they are not worth buying at all. Just like any othernew technology, hybrid cars also have their pros and cons. Theyare environment friendly and help in saving a lot of fuel. So, if youcan really afford to buy and maintain a hybrid car, you shoulddefinitely go for it.

6) MODELS OF HEV:


22/26


23/26


24/26


25/26


26/26

Physics project (Hybrid Electric Vehicle)

Documents

Transcript of Physics project (Hybrid Electric Vehicle)