hybrid electric vehicles, the story so far!

Hybrid Electric Vehicles Systems

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Hybrid Electric Vehicles, the story so far!

The emergence of hybrid vehicles is due to two major factors.Environmental problems caused by exhaust emissions, andthe decline in hydrocarbon based fuel reserves. What we needare green cars.

Explanation of Terms

The term "Hybrid" as such meansa mix or a combination. Withrespect to vehicle engineering,this term means that acombustion motor with standarddrive technology has beencombined with elements of anelectrical vehicle in one vehicle.

The Progression from Conventional Vehicles to Electric


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Categories of High Voltage Vehicles

Electric Vehicle (EV) / Battery Electric Vehicle (BEV):A vehicle powered solely by energy stored in an electrochemical device, generallyelectricity provided by batteries. An EV/BEV is not a hybrid electric vehicle

Extended Range Electric Vehicle (EREV):An electric vehicle equipped with an electrical generator (powered by an InternalCombustion Engine or ICE) that supplements the electrical propulsion system and extendsthe vehicle’s operating range

Hybrid Electric Vehicle (HEV):A vehicle powered by two or more energy sources and energy converters, one of which iselectricity. HEV’s usually combined the engine and fuel of a conventional vehicle with thebatteries and electric motor of an electric vehicle in a single drive train.Note: The term “Hybrid” may encompass vehicles with “Micro-hybrid” technology (whichrefers primarily to vehicles with “Start/stop” systems). Micro-hybrid vehicles are not HighVoltage Vehicles.

Plug-in Hybrid Electric Vehicle (PHEV):Hybrid vehicles that can charge their batteries from an external source in the same fashionas electric vehicles


Hybrid technology has three stages of complexity:

• The Micro Hybrid• The Mild Hybrid• The Full Hybrid Technology.


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Despite technical differences, all the technologies have the same working principle in thatthe battery used is charged by recovering the braking energy.

Hybrid Categories: Typical Specifications

Micro-Hybrid

Micro-Hybrids are usually equipped with a standard combustion motor, a Start Stopfunction and a braking energy recovery (regeneration) system.

• Typical motor/generator power 1 – 2 kW• Hybridisation ratio of < 4 %• Belt driven or crankshaft operation• Usually confined to engine start/stopoperation

In contrast, Mild Hybrids also have an additbattery. The electrical auxiliary drive is onlygreater power development when overtaking, th

• Typical motor/generator power 5 – 20 kW• Hybridisation ratio of 3 – 20 %• Typically with crankshaft mounted E machine• Torque assist and useful regenerative braking• No electric only mode• Medium to high voltage system, at least 42V D

• Limited regenerative braking capability

ional (small) electro-motor and a powerfulused as a support when starting and fore so-called “boost".

C

• Typical working voltage 14V DC


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Full/Strong Hybrids can not only "boost", they can also drive purely on electricity. To thisend, they are fully equipped with an electrical powertrain. However this requires a muchmore powerful battery than a mild hybrid.

Motor/generator power above 25 Kw Hybridisation ratio of 20 – 40 % High torque boost available High regenerative braking Electric only mode usually available High voltage system, typically over 200V DC

Plug-in-HybridOne of the Full Hybrid options is the "Plug-in-Hybrid". This is able to charge the batteriesovernight.The positive side effect of this type of vehicle is that the passenger compartment can bequickly brought to the required temperature allowing the vehicle to be ready for use againthe following morning.


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Hybrid Categories: Typical Specifications


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Mild and Strong Hybrid Electric Vehicle (HEV)

Plug-in Hybrid Electric Vehicle (PHEV)


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Additional descriptions of power distribution are:

Series Parallel Power split

Series Hybrid

In a series system, an internal combustion engine drives a generator which in turn drivesan electric motor which propels the vehicle.

Parallel Hybrid

In a Parallel System, the engine and electric motor can both power the vehicle.


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Power Split Hybrid

The Power Split System has advantages, however it is more complex.

Component Identification

Most Hybrid Systems use IMA(Integrated Motor Assist)

VW Touareg with IMA(Integrated Motor Assist)

hybrid electric vehicles, the story so far!

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