Transcript Building an Electric Vehicle: Components and Construction Part 1: Volkswagen Conversion Part 2: Electric Go-Kart Race Michael D.

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 Education
Department of Computer and Information Technology
(4) Lead Genomic Scientist
Bindley Bioscience Center at Discovery Park
Purdue University
West Lafayette, Indiana, USA
evw.tech.purdue.edu
Problems with EV propulsion
1. range: function of energy density of the battery.
Compare gasoline @ 12,000 (theo.) / 2600 Wh/kg
with 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 life — batteries priced @ $4,000 to $8,000
lasting about 2 years
Specific Energies of Battery Chemistries
lead acid
NiCd
NaS
NiMH
Li ion
gasoline
(Wh/kg)
35
45
80
90
150
12,000
(MJ/kg)
0.13
0.16
0.28
0.32
0.54
43
NOTE: 1 Wh/kg storage capacity equals about 1 mile driving range
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: $1,500
Batteries: $700
Electronics: $2,000
Batt Chargers: $500
Mechanical: $300
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 an
internal combustion engine.
Contactor: A relay that closes the “drive batteries”
circuit (i.e. turns the vehicle “on”)
Throttle Box
Shunt
Controller
Throttle and Controllers
Throttle Controls
Configuration:
5 k ohm sealed pot without 3-terminal
microswitch
Configuration
:
5 k ohm sealed pot with 3-terminal microswitch
Conection:
4 foot long, 2-wire unshielded, #22
AWG cable
Connectons:
Stroke:
Spring-returned lever arm drilled for
variable throw distances
Potentiometer: 4 ft. long, 2-wire unshielded,
#22 AWG cable
Microswitch: Three 0.188" X 0.018" tabs
Stroke:
Metal Parts:
Corrosion-resistant stainless steel
Spring-returned lever arm drilled for variable
throw distances
Dimensions:
3.75" H X 4.00" W X 2.06" D
Metal Parts:
Corrosion-resistant stainless steel
Dimensions:
3.75" H X 4.00" W X 2.06" D
Batteries : 6 x 12V lead-acid deep-cycle AND 1 x 12V for accessories
Controller
Used in the EV
Go-Kart
Used in the
VW conversion
Controller (Programmable through Software)
Electric Motor
Electric Motor Mount
Gauges
TESLA
$110,000
270 hp
EV-Bug
$5,000
27 hp
Tesla Battery
The 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 for
precise 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.
Chassis
Motor mount added to rear
Battery mounts
added to sides
of cart.
5 x 12V AGM Deep-cycle batteries in parallel
Some carts used lithium iron phosphate batteries (3.3 V)
Contactor
Fuses
Controller
Power Switches
60V system with top speed of about 40 mph, endurance at about 40 laps.
Technology and Innovation
1)
2)
3)
4)
Remote desktop to cart PC
Alter power settings during the race to optimize power/performance
Video feed sent to Jumbotron (entertainment)
Audio communications with driver
On-board Camera
GPS (speed)
Lap-top to controller
Blue-tooth helmet