Electric Motor

learnedbawledElectronics - Devices

Nov 24, 2013 (3 years and 11 months ago)

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The New
Standard of
Electric
Automobiles

TESLA ROADSTER

Cara
Hutter

and Tyler Starmack

Overview


Tesla Motors


Technology


Electronic Storage System


Power Electronics Module


The Electric Motor


Comparison


Efficiency


Emissions


Performance


Conclusion

Tesla Motors


Founded in 2003 in
Silicon Valley, California
by J.B.
Straubel

and
Elon

Musk


Exclusively develops and
manufactures electric
cars


Faced many challenges
as a start
-
up company


Has the goal of
transforming the
automobile industry


Introduced the Roadster
to the public in 2008




Technology of the Tesla Roadster


Three main systems

1.
Electronic Storage
System

2.
Power Electronics
Module

3.
Electric Motor

Electronic Storage System (ESS)


Powers the Roadster


990 pounds


Stores 56 kWh electric
energy


Delivers up to 215 kW
electric power


Can travel 200 miles on
a single charge


Can accelerate from 0
to 60 mph in less than
4 seconds

ESS (
cont
)


Made up of 6,831
Lithium
-
ion
cells


Cells distributed into
11 sheets to facilitate
climate control


Many safety systems


Current Interrupt
Device (CID)


Fuses


Microprocessors

Power Electronics Module (PEM)

Power Electronics Module


Acts as an “energy bridge”


Controls current (converts AC to DC and vice versa)


3 main systems


Power stages (
Megapoles
)


Arrays of switches to control whether battery is connected to charge
port or motor


Insulated Gate Bipolar Transistors (IGBT) control amount and type of
current


Controller


Manages the
p
ower stages


Contains the digital signal processor and the secondary signal
processor


Line filter


Contains a series of inductors that filter out electric noise when
charging


The Electric Motor

The Electric Motor


3 phase induction
motor


900 amperes of
current required


Uses alternating
current


Provides instant torque
(unlike an internal
combustion engine)


No gears required


Has large effect on the
Roadster’s efficiency

Well
-
to
-
Wheel Efficiency


Well
-
to
-
wheel efficiency calculation


Fuel source energy content (MJ/kg)


Fuel conversion energy content (MJ/kg)


Vehicle fuel efficiency (km/MJ)


Overall efficiency (km/MJ)



Efficiency Comparison

1993 Honda Civic VX


Gasoline
-
powered


Energy Content


47 MJ/kg


Production Efficiency


81.7%


Vehicle Fuel Efficiency


51 miles
-
per
-
gallon (MPG)


Overall Efficiency


0.52 km/MJ


Most efficient gasoline
-
powered vehicle to date


2008 Tesla Roadster


Electric


Natural gas
-
fired generator


60% efficient


Natural gas processing


87.5% efficient


Lithium
-
ion battery


86% efficient


Vehicle Efficiency


2.53 km/MJ


Overall Efficiency


1.15 km/MJ

Well
-
to
-
Wheel Efficiency

2.21 times more efficient than the Honda Civic VX

2.05 times more efficient than the Toyota Prius

Well
-
to
-
Wheel Emissions


Well
-
to
-
Wheel Emissions Calculation


Fuel source carbon content (g/MJ)


Carbon conversion to carbon dioxide


3.67 grams of carbon per gram carbon dioxide


Overall vehicle efficiency (km/MJ)


Overall carbon dioxide emissions

Emission Comparison

Honda Civic VX


Crude oil carbon content


19.9 g/MJ


Carbon dioxide content


73 g/MJ


Overall efficiency


.52 km/MJ


Overall carbon dioxide
emission


141.7 g/km

Tesla Roadster


Natural gas carbon
content


14.4 g/MJ


Carbon dioxide content


52.8 g/MJ


Overall efficiency


1.15 km/MJ


Overall carbon dioxide
emission


46.1 g/km

Well
-
to
-
Wheel Carbon Dioxide Emissions

3.07 times fewer emissions than the Honda Civic VX

2.84 times fewer emissions than the Toyota Prius

Overall Vehicle Performance


Measured by a combination of torque (horsepower)
production and efficiency


In order to be considered “high
-
performance” a vehicle
must be able to produce torque quickly


Provides rapid acceleration

Performance Comparison

Internal Combustion Engine


Little to no torque production
at low RPM


Limited range of sustained
torque


280
ft
*
lb

from 4,500
-
6,500 RPM


30% of energy in gasoline is
converted to torque


Linear motion must be
converted to rotational


Must idle at 1,000 RPM


Rapid acceleration


High horsepower


P
oor gas mileage


High emissions


Electric Motor


High torque production at low
RPM


Only begins to significantly
decline at around 6,000 RPM


300
ft
*
lb

instantaneously
-
4,500
RPM


Motor is 88% efficient


Converts electricity to power


Direct rotational motion


Rapid acceleration


High horsepower


High efficiency


Low emissions


0
-
60 mph Acceleration

Better acceleration than any high
-
performance, gasoline
-
powered automobile.

5.23 times more efficient and 7.12 times fewer emissions than the Porsche Turbo



The only reason that (electric) car isn't everywhere: it
couldn't go more than 70 miles on a charge. But you make
it 270, game over. Anybody who drives it will never go back
to internal
combustion.”
-
MIT Professor Donald
Sadoway


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