hybrid vehicles
DESCRIPTION
hybrid vehicles hybrid vehiclesTRANSCRIPT
Aims and Objectives
Aim
•To be able to describe the operation of a vehicles hybrid system
Objectives
•To recognize the need for alternative fuels• To be able to describe the operation of a hybrid system•To be able to comment on the use of hybrid systems
Hybrid VehiclesBy Waqas CH
Why do we need alternative fuels?
We need alternative fuels as our supply of fossil fuels (that make petrol and diesel) are becoming less and less.
To make an effort to reduce our carbon footprint.
To reduce the amount of harmful gases produced by vehicles.
Hybrid Vehicles
Question
In pairs discuss some other reasons why we might benefit from alternative fuels.
Hybrid Vehicles
Alternative Fuels
Ethanol
Reduces the green house gases produced by vehicles, is commonly mixed with petrol to run motor vehicles:-
E10 10% Ethanol 90% PetrolE85 85% Ethanol 15% Petrol
(no difference in performance to the two)
Hybrid VehiclesBy Waqas CH
Alternative Fuels
Ethanol Plus points
•Lower Emissions•More resistance to engine knock•Added vehicle cost is minimal
Ethanol Negative points
•Flex fuel vehicle •Lower energy content•Limited Availability
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Alternative Fuels
Bio Diesel
Is made up of crops, or even old restaurant oilCan be used on its own or blended with petrol
Hybrid Vehicles
Alternative Fuels
Bio Diesel Plus points
•Can be utilised in most diesel engines•Less air pollutants•Biodegradable•Non-toxic•Safer to handle
Bio Diesel Negative points
•May not be approved by the manufacture•Lower fuel economy •More nitrogen oxide•Not suitable in lower temperature•Concerns over engine durability
Hybrid Vehicles
Alternative Fuels
Natural Gas
Can be used to fuel the car as a gas or a liquidCan be utilised within duel fuel vehiclesStored in high pressure tanks (therefore two fuelling systems are required within the vehicle)
Hybrid Vehicles
Alternative Fuels
Natural Gas Plus points
•60-90% less smoke producing emissions•30-40% less Green House gasses emitted•Less expensive
Natural Gas Negative points
•Fewer miles per tank•Less available •Limited to the type of vehicles it is available on
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Alternative Fuels
Propane LPG
Clean burning fossil fuelContains fewer toxinsMust have a separate fuelling system for the two fuels (petrol and LPG)
Hybrid Vehicles
Alternative Fuels
Propane Plus points
•Fewer toxins and smog emitting pollutants•Less expensive
Propane Negative points
•Not currently readily available on newer models•Fewer miles available per tank of fuel
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Alternative Fuels
Hydrogen
Hydrogen is been readily looked at as an alternative for petrol/diesel.Environmentally friendly fuel, however, there are challenges that stop this fuel being currently widely used.
Hybrid Vehicles
Alternative Fuels
Hydrogen Plus points
•Produced from several sources•No air pollutants produced•Produces only NOX
Hydrogen Negative points
•Expensive•Fuel cells can be expensive•Lower energy density then fuel
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Alternative Fuels
Questions
Give two advantages and disadvantages of hydrogen fuel?
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Hybrid Vehicles
Can be split into two sections:-Series and Parallel
SeriesThe vehicles Engine will drive the generator which in turn powers the vehicle.
ParallelEngine and motor can be used to drive the vehicle, this system employs brake energy regeneration. This is the most favoured amongst manufactures.
Hybrid Vehicles
Question
What are the two sections that hybrid vehicles can be split into?
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Hybrid Vehicles
The main components include:-
MotorHigh Voltage BatteryPower drive UnitDC converter (direct current)
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Toyota Prius
Uses a Power Split system
1)the high voltage battery provides power to the motor to drive the wheels
2)Wheels are driven by engine to power splitting device. The generator is driven by planetary gears to provide the motor with electricity to drive the wheels
3)During de-acceleration energy is recovered at the wheels, the energy in converted to mechanical energy to charge the vehicles high voltage battery
Hybrid Vehicles
Hybrid Vehicles
Toyota Prius
Power Splitter
Is a epicycle gear box, that transmits energy in main components.
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Toyota Prius5 Operating Modes
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Question
Name one of the five modes that hybrid vehicles use.
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Hybrid Vehicles
Toyota Prius
Start up
Under normal conditions the motor will start the engineUnder poor start up conditions the 12v starting system will start the vehicle
Hybrid Vehicles
Hybrid Vehicles
Toyota Prius
Acceleration
DC is converted to AC via the power drive unitThis is used as supply to the motorIt is also used to supplement engine output
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Hybrid Vehicles
Toyota Prius
Cruise
Engine drives the motor (which acts as a generator) The output current drives the motorConverted to 12v DC supplies the vehicles charging system
Hybrid Vehicles
Hybrid Vehicles
Toyota Prius
Deceleration Motor is driven by the wheels under deceleration conditions, regeneration takes placePower drive unit converts AC current to DC current to charge the batter module. Some energy is then used to charge the 12v electrical system.If ABS senses wheel lock up, a signal is sent to the ECU and re-generation stops to prevent interference.
Hybrid Vehicles
Hybrid Vehicles
Toyota Prius
Idle
The flow of energy is similar to that of cruisingIf the charge of the battery is low, the ECU will raise the vehicles idle speed to compensate for this.
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Summary - have we ?
Recognized the need for alternative fuels ?
Can we describe the operation of a hybrid system ?
Are we able to comment on the use of hybrid system ?
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Any Questions ?
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