advances in automotive electrical systems- for any body who wants to know

7/29/2019 Advances in Automotive Electrical Systems- for any body who wants to know.

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PSG College of Technology

RECENT TRENDS IN AUTOMOTIVEELECTRICAL SYSTEMS

BY,Prof. M . AdimurthyBLDEAs college of Engg. And TechnologyBijapur 586103


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AGENDA Basic Electrical Terminology

Different Electrical Loads in a Vehicle

Battery

Technology Today 42 V Technology

Integrated Starter Generator

Electromagnetic Valves

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BASIC ELECTRICAL TERMINOLOGY CURRENT: The flow of electrons through a conductor

caused by the application of a potential differencebetween its ends.

VOLTAGE: It is the force or pressure that causes the

electrons to flow through the conductor.

RESISTANCE: It is the factor that resists the flow ofcurrent through a conductor.

POWER: power is defined as the rate of doing work.P = V x I

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WATER ANOLOGY OF ELECTRIC CIRCUIT

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WATER ANOLOGY OF ELECTRIC CIRCUIT

The rate of flow of water (current (I)) is measured by theflow meter (ammeter (A)).

The rate at which water flows through the pipe depends

on the pressure (voltage (V)), is indicated by pressuregauge (voltmeter).

Power required to run the water motor (starter motorP=VI) is directly proportional to the rate of flow (voltage

(V)) and the quantity of water in the pipe (current (I)).

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THE 12V ELECTRICAL SYSTEM

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Head light 12 V, 60/55 W

Indicator light 12 V, 21 W

Tail / Brake light 12 V, 21 W

Number plate light 12 V, 5 W

Room light 12 V, 5W

Starter motor 300 400 Amps (starting)Parking light 12 V, 21 W

ELECTRICAL LOADS - MARUTI 800

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Head light 12 V, 35 W

Indicator light 12 V, 10 W

Tail / Brake light 12 V, 10/5 W

City lamp 12 V, 3.4 W

Starter motor 12 V, 5 Amps.

ELECTRICAL LOADSMAX 100 R

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BATTERY - TYPES

(i) Lead Acid Battery

(ii) Nickel Cadmium Battery

(iii) Nickel Iron Battery

(iv) Nickel Metal Hydroxide Battery

(v) Zinc Bromine Battery

(vi) Sodium Sulfur Battery

(vii) Sodium Nickel Chloride Battery

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BATTERYTYPES (Contd..)

The most successful battery in terms of reliability, life

expectancy and cost is the lead acid battery. A 12 V battery which has 6 cells producing 2V each.

Lead acid battery still being used in EVs, moreresearches are going on advanced lead acid batteries.

Nickel cadmium battery longer life, good lowtemperature performance, high power capacity.

Disadvantage - High cost and toxic nature of cadmium.

Nickel iron battery longer cycle life than lead acidbattery

High Maintenance

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ELECTRIC VEHICLE BATTERYREQUIREMENTS

High specific energy

High specific power

High efficiency

Longer cycle time

Reasonable recharge time

Recyclable material

Low cost

Safety

Reliability and low maintenance

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BATTERY CHARACTERISTICS

Specific power (W/Kg) An indicator of the maximumpower that the battery can deliver instantaneously(decides EVs acceleration and hill climbing)

Specific energy (Wh/Kg) Energy capacity per unitweight of the battery (decides driving range)

Energy density (Wh/m3) How much energy per unitvolume of the battery can store (decides space on the

vehicle) Cycle life measured in number of cycles.

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COMPARISON OF BATTERYTECHNOLOGIES (RELATIVE TO LEAD-ACID)

BatteryTechnology

SpecificPower (W/Kg)

EnergyDensity Wh/l

SpecificEnergy Wh/Kg

Cycle life

Lead-acid 35 300 50 90 15 45 300 600

Nickel-iron 70 130 60 100 35 60 400 1200

Nickel-cadmium

100 200 60 100 30 60 1000 1500

Nickel-metal 140 200 100 210 55 80 1000

Sodium sulfer 90 120 75 110 80 120 250 500

Sodium nickelchloride

150 160 100 500

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CHARGING SYSTEM The alternator is a device which generates

alternating current to charge the battery as well as tocater the various electrical loads when the engine isrunning.

It works on the principle of electromagneticinduction.

The alternator takes its drive from the enginecrankshaft.

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STARTING SYSTEM

The starter motor (self starter) converts theelectrical energy stored in the battery intomechanical energy to crank the engine.

The cranking motor consumes a very high currentduring cranking the engine.

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TECHNOLOGY TODAY 6 Volt systems were used till 1950

In the 1950s, The implementation of high power headlights,radios, and high compression V8 engines, which requiredhigher ignition energy, created the need to move away fromthe 6-volt battery system to A 12-volt system.

12 to 14 volt systems are being used today

Most, if not all of the accessories are currently dependingupon on engine power.

With the planned implementation of advanced electronicsystems, a shift away from the current 14-volt electricalsystem to a new 42-volt electrical system is required.

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42 VOLT TECHNOLOGY HISTORY Vehicle electrical demand has doubled over the last 20

years

On research from 1980s

Rapidly emerging as the technical solution forimproved fuel consumption and higher electrical powerrequirements

Keeping wiring harnesses small and light weight are adefinite advantage in manufacturing and long term fueleconomy

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42 VOLT TECHNOLOGY HISTORY (contd..) MERCEDES BENZ has been studying the feasibility

from the early 1990s

MIT The mastermind for this technology

34 countries to introduce the technology soon

JAPAN will be the first to introduce this technology

42 Volts and its resulting higher power will be the

enabler for a range of new technologies like EPS,water pumps, door closes and advanced braking andsuspension system

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CURRENT TECHNOLOGIES THAT WILLBENEFIT FROM 42-VOLT SYSTEM

Technology Benefits

Electric power steering More power, improved fuel economy

Heated catalytic converter Lower emissions, quicker light off time

Mobile multimedia More power for video, navigationsystem, fax, amplifiers, cell phones

Fuel pumps Reduced size and increasedperformance

Heated seats More power, improved fuel economy

HVAC Smaller and lighter units, betterpackaging

Power windows, seats, lift gates Reduced size of motors, moreefficient operation

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42V - ADVANTAGES

Based on one of the basic laws of electricity i.e. thehigher the voltage, the more current will flow through aconductor. So through a small size cable, it is able toconduct more current.

So we moved from 6 V to 12 V

in future 12 V to 42 V

It supports more powerful electrical devices like micro

contollers, mind blowing sound system, luxuries suchas heated seats, heated steering wheels, heads-updisplays and navigations systems.

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42VADVANTAGES (Contd..) Electrical power generation by charging system

requires lot of fuel.

It saves 15% of fuel for every 1 KW of power

produced by the alternator.

It can significantly reduce vehicle wiring size andweight compared to existing 14-volt configurations.

In 12 V system the resistance in an electricalconnector will cause change in current flow whichcause computer to receive wrong inputs.

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42VADVANTAGES (Contd..) Since 42 V technology has the ability to overcome

resistance in wire connections, ECMs receives rightsignals at right time.

The improved performance that are possible under a42-volt system

1. Decrease of the amount of power drained off thepower train by belt driven components andaccessories. (fuel consumption is reduced)

2. Flexibility to accommodate driver assistancetechnologies like collision avoidance systems, parkingassistance etc.

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SINGLE 42 VOLT SYSTEM

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SINGLE 42 VOLT SYSTEM The simplest design on paper, but its the hardest to

put into production,

It requires that all of the electrical components in thevehicle be redesigned to operate on 42-volts.

A single 42-volt system would avoid cost, weight andpackaging problems created by a second battery.

Because of the high initial costs of implementing asingle 42-volt system, a dual-voltage architecture ispreferred.

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INDUSTRIAL IMPACT

The list of 12-volt products and systems that will feel adirect impact by the shift to 42-volt standards is quiteextensive.

More obvious are the mechanical devices and systemsthat can readily be replaced by electronic versions:water pumps, air conditioning compressors, and the like.

Within 10 years we will see a move to 42-volt systems inan attempt to improve fuel consumption, decreaseemissions and provide consumers with more options.

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INDUSTRIAL IMPACT Falling revenue and a shrinking market will inevitably

affect investment in new mechanically driven productsand the processes that produce them.

As the auto industry changes over to the 42 voltstandard, and begins eliminating belt-drivencomponents, companies that are not ready for radical

changes in engine technology, will find themselves ata competitive disadvantage.

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HOW TO USE CURRENT 12 V SYSTEM

COMPONENTS IN 42 V SYSTEM?

Modules will convert 42 V of charging system into12 V, so 12 V system component can be used with

42 V technology. A common module will be located at the centre of

the vehicle powering several 12 V systemcomponents.

Advances in electronics may allow each 12 Vdevice to have its own module.

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DISADVANTAGES

Safety is a concern with 42 V power systems.

In 42 V, arcing effect can generate temperatures

above 1000oC Fire hazard develops.

By mistake or accidentally a car ownerdisconnects a live wire or a switch becomesfaulty - Fire hazard develops.

Costly.

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AUTO ANCILLARY MANUFACTURES

CHALLENGES Higher power relays, switches, standardized

components such as connectors, fuses andsemiconductor devices are need to be developed for

this system. Due to the enormous 14-V component infrastructure, the

first 42-volt systems will be dual voltage systems.

Manufacturers will also have to consider how to handlethe aftermarket items that consumers add, like foglamps, radar detectors, etc.

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INTEGRATED STARTERGENERATOR(ISG)

It replaces the conventional starter motor andalternator (generator).

Apart from its two basic function (starter and

alternator), an auxiliary one, as a convenientautomatic vehicle start stop system for improved fuelefficiency.

The electronic control system switches off the engineat zero load (when standing at traffic light) and

automatically restarts using the ISG very rapidly whenthe accelerator pedal is pressed.

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INTEGRATED STARTERGENERATOR (ISG)

(Contd..)

During braking the ISG can convert the Kinetic Energy (KE)into Electrical Energy (EE) and them feed this power back intoelectrical system.

As it fully supports the stop and start operation, electric drive-

off, acceleration and recycling of braking energy the ISGhelps to reduce both fuel consumption and emissions.

The compact dimensions of the ISG allow it to be placeddirectly on the crankshaft between the engine and thetransmission.

The ISG electro-magnetically transmits its force to thecrankshaft when the key is turned and starts the engine at afraction of the time it would take a conventional starter.

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INTEGRATED STARTERGENERATOR (ISG)

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INTEGRATED STARTER - GENERATOR

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ISG - NECESSITY To eliminate starter which is only a passive component

during engine operation.

To replace belt and pulley coupling between thealternator and the crankshaft.

To eliminate slip rings and brushes used in alternators.

ISG acts as a bi-directional power converter, changingmechanical energy into electrical energy and vice

versa.

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ADVANTAGES Because of its start-stop and the recuperative braking capability

and higher voltage makes the ISG more efficient than a

conventional generator resulting in upto 20% reduced overallfuel consumptions.

Because using ISG no fuel enrichment is necessary to start theengine lower start emissions can be achieved, especially duringthe cold start period.

It can achieve noise and vibration reduced operation improvingcomfort.

The components of the ISG system are not subject to wear andtear and are maintenance-free because of the systems

brushless design. ISG Can be integrated with most of actual car models, therefore

is no need to develop a new car model or significantly modifyan existing car. Thus it is very cost-efficient system.

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CHALLENGES High starting torque at most unfavorable operating

conditions.

Wide speed range in generator mode.

High efficiency in wide speed range (600 8000 rpm).

Vibrations of up to 20 g in crankshaft mounted systems.

Cycle life over 250 000 stop/start cycles in 10 years.

Good serviceability, high reliability, acceptable cost, etc.

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ELECTROMAGNETIC VALVES (EMV) Used in camless valve actuation

Electromagnetic valves (EMV) would be actuated by

sending current pulses through spring-loaded solenoids

with the valve stems as their cores Therefore they could be opened and closed without regard

to crankshaft position.

This would allow each valve to be controlled independently

for timing, profile, and liftgiving far more flexibility than

any crankshaft driven variable valve timing system.

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ELECTRICALLY HEATED CATALYTICCONVERTER

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ELECTRICALLY HEATED CATALYTICCONVERTER

The electrically heated catalytic converter is another newkind of load on the battery.

The electric heater will get the catalytic converter up to

temperature quickly, which is important because aconverter can reduce nitrogen emissions (NOX) only whenit is hot.

Another proposal calls for preheating the catalytic converter

from a dedicated battery before start-up. Such heaterscould eliminate a large source of pollution--emissions fromcold engines.

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ELECTRICAL ACTIVE SUSPENSION

Active suspension system, will keep the passengercompartment on a flat trajectory (constant ride height) as thecar wheels encounters a bump, bounce over potholes andrough roads.

The system senses a vehicle's vertical accelerations and

energize electromechanical actuators to counter them. Although active suspension is available today on some high-

end luxury vehicles, it does not have the bandwidth of a fullyelectrical system and therefore does not achieve its fullpotential.

Expensive, heavy, and power-intensive, an active suspensionsystem will need very high voltages to operate efficiently.

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SUSPENSION BY WIRE Hydraulically operated but electronically

controlled

Road profile is sensed

Other method is calculating vertical wheelheight

Coil springs also present for more comfort

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ELECTRIC POWER STEERING

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ELECTRIC POWER STEERING The current mechanical power steering system continually

place a small load on the engine even when steering assistis not required.

A small permanent-magnet motor powered by the vehicle

battery supplies the effort necessary instead of a hydraulicjack powered by a pump.

The systems steering effort is correlated to vehicle speed,steering torque and steering position.

An advanced feature of EPS systems can actually helpenhance the return ability characteristics of the steeringwith its assisted return-to-center feature.

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ELECTRIC POWER STEERING Some manufacturers like Honda currently offers EPS on

their niche products like the NSX, S2000, and the Insighthybrid.

The disadvantage under the current 14-volt systems is theirlarge current requirement during low speed maneuvers,which makes them only applicable in small to midsizevehicles.

The move to 42-volt will allow the use of EPS on all cars,

SUVs, and light commercial vehicles.

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ELECTROMECHANICAL BRAKES

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ELECTROMECHANICAL BRAKES (EMB) Electromechanical Brakes (EMB) dispense with the

master cylinder, vacuum servo, all hydrauliccomponents, and hydraulic fluid found in aconventional brake system.

With an EMB system, Functions such as Anti-lockBraking System (ABS), Traction Control System (TCS),vehicle stability, and Panic Brake Assistance alsopossible.

So this system demands a new 42V system to beimplemented in the future cars.

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ELECTRIC WATER AND OIL PUMPS To improve the mileage, the only solution is transition of

engine driven water pump and oil pump to the systemsrun on electricity.

With the implementation of 42-volt, the engine

management system can be designed to control anindependently driven electric water pump to efficientlyprovide cooling demand while allowing forimprovements in fuel efficiency.

The electric load and speed variation needed toimplement these electric pumps can only be providedby a 42-volt system.

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ELECTRIC AIR-CONDITIONING

In contemporary A/C configurations, the compressor isdriven off of the accessory belt, via an electro-magnetically clutched pulley on the compressor.

When the engine is shut off at a stop there is an

electro-magnetic clutch on the crankshaft instead of thecompressor, which disengages.

At this point the Starter/Generator spins the accessorybelt. This system is only electrically driven when the

engine is not running.

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MOTORS AND ACTUATORS In a 12 V system, motors lose 15% of their energy in

the brushes alone.

Many automakers favor 42 V DC, which can readilybe handled by power MOSFETs made by thestandard 60-V process.

42V motors can be made comparatively smaller insize, which could mean thinner doors that offer morepassenger room, or even additional storage spaceunder seats.

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STEER BY WIRE TECHNOLOGY

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EMBEDDED

SYSTEMS play aimpotant role.

DELPHI and BMWare working togetherfor years.

Reaction time is muchquicker than

HYDRAULICSCIRCUIT

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THROTTLE BY WIRE TECHNOLOGY Eliminates the mechanical elements of a throttle

substituted with fast responding electronic circuits

Greater accuracy of data improves the drivability of the

vehicle Reduces the number of moving parts

There is no possible wear in parts

Thus less maintenance and more life

Reduces the drivers fatigue.

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BRAKE BY WIRE TECHNOLOGY Dry electrical components systems replaces conventional

actuators with electrical motor-driven units

ADVANTAGES

Connects with emerging systems, such as ABS and

Adaptive Cruise Control (ACC)

Reduces system weight to provide improved vehicleperformance requirements

Supports better control over the brake even in hill roads

also Removes mechanical components for freedom of design

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SAFETY IMPROVEMENT USE OF ADVANCED


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SAFETY IMPROVEMENT USE OF ADVANCEDELECRICAL TECHNOLOGIES

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PROPOSED SYSTEMARCHITECTURE

Single 42-volt systems

Dual Alternator Dual voltage

o

Dual Alternatoro Dual starter

o DC/DC Converter

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ON GOING PROJECTS IN ELECTRICALS AND


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ON GOING PROJECTS IN ELECTRICALS AND

ELECTRONICS

Investigate the design and control of high-poweralternators incorporating power electronic controls.

Investigate the application of a new composite magneticmaterial to the development of new permanent magnetmachines that can achieve higher performance at lowercost for automotive applications.

Modelling and controlling energy flow in advancedautomotive electrical system.

Investigate advanced topics in fault detection andcorrection in dual-voltage systems.

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THANK YOU

advances in automotive electrical systems- for any body who wants to know

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