building an electric vehicle

7/29/2019 Building an Electric Vehicle

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Building an Electric Vehicle:

Components and Construction

Part 1: Volkswagen Conversion

Part 2: Electric Go-Kart Race

Michael D. Kane, PhD(1) Associate Professor of Bioinformatics(2) University Faculty Scholar

(3) Chair of Graduate EducationDepartment of Computer and Information Technology

(4) Lead Genomic ScientistBindley Bioscience Center at Discovery Park

Purdue UniversityWest Lafayette, Indiana, USA

evw.tech.purdue.edu
http://bioinformatics.tech.purdue.edu/http://bioinformatics.tech.purdue.edu/


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1. range: function of energy density of the battery.

Compare gasoline @ 12,000 (theo.) / 2600 Wh/kgwith the lead-acid battery @ 175 (theo.) / 35 Wh/kg

2. time to refuel: charge 40 kWh in 5 minutes?

220 V 2200 A!!!

When you pump gasoline @ 20 /min,

your energy transfer rate is about 10 MW!(Hint: energy density of gasoline is 10 kWhth/.)

3. cost:

(a) light but safe means higher materials costs,

e.g., less steel, more aluminum; and higher processing costs,

e.g., fewer castings, more forgings...(b) to reduce load on the battery requires high efficiency appliances = costly

(c) low cycle lifebatteries priced @ $4,000 to $8,000

lasting about 2 years

Problems with EV propulsion


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Specific Energies of Battery Chemistries

(Wh/kg) (MJ/kg)

lead acid 35 0.13

NiCd 45 0.16

NaS 80 0.28

NiMH 90 0.32

Li ion 150 0.54gasoline 12,000 43

NOTE: 1 Wh/kg storage capacity equals about 1 mile driving range


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Specifications & Performance:

http://evw.tech.purdue.edu

Drive system: 72 volts (lead acid)Top Speed: 40 mph

Distance: 25 miles

Cost: $5,000 (total)

Vehicle: $1,500Batteries: $700

Electronics: $2,000

Batt Chargers: $500

Mechanical: $300


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Original VW Motor: 150 pounds (70 kg)55 hp

Conversion to Electric Motor: 70 pounds (30 kg)27 hp*200 pounds (90 kg) in batteries.

Conversion is +120 pounds (55 kg)

* The electric motor used in the conversion is rated at 15 hp (peak),but calculating horse-power in an electric motor is different than aninternal combustion engine.


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Contactor: A relay that closes the drive batteries

circuit (i.e. turns the vehicle on)

Throttle Box

Controller

Shunt


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Throttle and Controllers


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Configuration: 5 k ohm sealed pot without3-terminal

microswitch

Conection: 4 foot long, 2-wire unshielded, #22AWG cable

Stroke: Spring-returned lever arm drilled forvariable throw distances

Metal Parts: Corrosion-resistant stainless steel

Dimensions: 3.75" H X 4.00" W X 2.06" D

Configuration

:

5 k ohm sealed pot with 3-terminal microswitch

Connectons: Potentiometer: 4 ft. long, 2-wire unshielded,#22 AWG cableMicroswitch: Three 0.188" X 0.018" tabs

Stroke: Spring-returned lever arm drilled for variablethrow distances

Metal Parts: Corrosion-resistant stainless steel

Dimensions: 3.75" H X 4.00" W X 2.06" D

Throttle Controls


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Batteries : 6 x 12V lead-acid deep-cycle AND 1 x 12V for accessories


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Controller

Used in theVW conversion

Used in the EV

Go-Kart


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Controller (Programmable through Software)


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Electric Motor


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Electric Motor Mount


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Gauges


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TESLA$110,000

270 hp

EV-Bug$5,000

27 hp


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Tesla BatteryThe pack weighs 990 pounds, stores 56 kWh of electric energy, and delivers up to 215 kW of electric power,

375 volts. Battery cost is about $30,000

Each cell is 18mm in diameter by 65mm length, The small cell size enables efficient heat transfer, allows forprecise charge management, improves reliability, and extends battery pack life. Each cell is enclosed in a

steel case which effectively transfers heat away from the cell. The small size makes the cell essentially

isothermal, and its large surface area allows it to shed heat to the ambient environment.

Sixty-nine cells are wired in parallel to create bricks. Ninety-nine bricks are connected in series to create

sheets, and 11 sheets are inserted into the pack casing. In total, this creates a pack made up of 6,831 cells.


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Chassis

Motor mount added to rear

Battery mountsadded to sides

of cart.


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5 x 12V AGM Deep-cycle batteries in parallel


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Some carts used lithium iron phosphate batteries (3.3 V)


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Controller

Power Switches

Fuses

Contactor


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60V system with top speed of about 40 mph, endurance at about 40 laps.


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Technology and Innovation

On-board CameraGPS (speed)Lap-top to controllerBlue-tooth helmet

1) Remote desktop to cart PC2) Alter power settings during the race to optimize power/performance3) Video feed sent to Jumbotron (entertainment)4) Audio communications with driver


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building an electric vehicle

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