Design SolutionsSponsored by: National Science Foundation

Advisors: Abdullah Eroglu, Hosni Abu-Mulaweh, Hossein Oloomi

Team Members: Mitchell Eilerman, Leandra Lee, Charles McIntosh, Josh Weaver, Andres Cobos, Austin Swihart

March 19, 2015

IPFW Electric Vehicle

Project Overview

Electrically powered vehicle with solar recharge

Uses data and equipment from previous senior design

projects

Bipolar DC-DC converter with four quadrant topology

Solar Panel

Mini-Baja frame

Project Overview

Project’s Final Goals:

Reach speed of 10 mph in 15 seconds

time

Achieve Driver Controlled Speed

Design Cooling System

Provide information display

Stay within $1000 budget

Project Diagram

Solar Panel

Battery

Battery

DC-DC Converter

Arduino

DC-DC Converter

Motor

Heat Dissipation

Tra

nsm

issi

on

Subsystems

DC-DC Converter

Control System

Cooling System

Charging System

DC-DC Converter Concepts

Decoupling capacitors

Decoupling capacitors and shielding

Decoupling capacitors, shielding, separate Arduino from MOSFET

drivers, and reduce the length of the wires

Concept 1: Decoupling capacitors

Advantages: Drastically reduces switching noise Relatively simple design

 

Disadvantages: Consume more space High Cost

+15VConverter

+9VConverter

+5VConverter

+24 V +15 V +9 V +5 V

Concept 2: Decoupling capacitors & shielding

Advantages:

Least expensive solution

No relocation of components

Disadvantages:

Consumes space

System more unwieldy

Wires

Arduino microcontroller

Concept 3: Decoupling capacitors, shielding, separate Arduino from MOSFET drivers, and reduce the length of the wires

Advantages: Less affected by interference from MOSFET drivers May be placed closer to any needed sensors

 

Disadvantages: There may not be space Longer wires cause additional power loss Longer wires introduce additional noise

MOSFET drivers

Arduino microcontroller

Control System Concepts

Pedal press linear with speed

Pedal press linear with voltage

Two-state system: acceleration and constant speed

Concept 1:Pedal press linear with speed

Advantages:

More accurate control of speed

Pedal scheme relatively easy to learn

Disadvantages:

Significant testing required

Concept 2: Pedal press linear with voltage

Advantages:

Control code already designed for application

Disadvantages:

Harder for driver to control vehicle speed

Concept 3: Two-state system: Acceleration and constant speed

Advantages:

Accelerates at set rate

Easier to maintain speed

Disadvantages:

Cannot directly control acceleration

Steep learning curve

Cooling system

Forced convection by use of fans

Radiator with a water jacket

Fin and fan combination

Concept 1: Forced convection by use of fans

Advantages:

Simple and easily implemented

Reliable, low maintenance and inexpensive

Can affect a large area of components

Free convection changed to forced convection

Can remove variable amount of heat

Disadvantages:

Relies on the ambient air

Concept 2: Radiator with a water jacket

Advantages:

High capacity for heat removal

More easily controlled

 Disadvantages:

Components will require a partial disassembly to maintain

Potential safety issues

Requires large amount of energy from batteries

More complicated and more maintenance

Concept 3: Fin and Fan combination

Advantages:

Low maintenance

Localized heat removal

Low cost

Disadvantages:

Relies on ambient air temperature

Charging System Concepts

Use existing 48V booster

Replace booster with 24V booster

Include AC option with either of the previous

ideas

Concept 1: Use Existing 48V booster

Advantages:

No additional purchasing of parts

Allows batteries to reach peak voltage

Disadvantages:

The charge time of the batteries will be increased

Power will be lost

System is dependent on light available

Concept 2: Replace booster with 24V booster

Advantages:

Higher efficiency

Charges the batteries faster

Disadvantages:

Purchase of a new booster is necessary

System is dependent on light available

Concept 3: Include AC option with either of the previous ideas

Advantages:

Charges more quickly if an AC power source available.

Can be charged without light source. 

Disadvantages:

No longer solely dependent on solar energy

Control system must be developed

Additional space is needed for the system

Cross’s Matrix - DC-DC Converter

DC-DC Converter

Cost x 9 1 9 9

Ease of Design 1 x 1 9 9

Size 9 9 x 9 9

Safety 1 1 1 x 1

Reliability 1 1 1 9 x

0.12 0.20 0.04 0.36 0.28

Cross’s Matrix - Control System

Control System

Cost

Ease

of D

esign

Safe

ty

Mainte

nanc

e

Relia

bility

Cost

Ease

of D

esign

Aesth

etics

Size

Weig

ht

Safe

ty

Mainte

nanc

e

Relia

bility

Ease

of D

esign

Safe

ty

Mainte

nanc

e

Relia

bility

Cost

Ease

of D

esign

Size

Safe

ty

Relia

bility

Ease of Design x 9 9 9

Safety 1 x 1 4

Maintenance 1 9 x 9

Reliability 1 4 1 x

0.05 0.38 0.19 0.38

Cross’s Matrix - Cooling SystemCooling System

Cost

Ease

of D

esign

Safe

ty

Mainte

nanc

e

Relia

bility

Cost

Ease

of D

esign

Aesth

etics

Size

Weig

ht

Safe

ty

Mainte

nanc

e

Relia

bility

Ease

of D

esign

Safe

ty

Mainte

nanc

e

Relia

bility

Cost

Ease

of D

esign

Size

Safe

ty

Relia

bility

Cost x 9 1 1 9 9 4 9

Ease of Design 1 x 1 1 4 9 1 9

Aesthetics 9 9 x 9 9 9 9 9

Size 9 9 1 x 9 9 9 9

Weight 1 4 1 1 x 9 1 9

Safety 1 1 1 1 1 x 1 1

Maintenance 4 9 1 1 9 9 x 9

Reliability 1 1 1 1 1 9 1 x

0.09 0.15 0.03 0.05 0.15 0.23 0.09 0.20

Cross’s Matrix - Charging System

Charging System

Cost

Ease

of D

esign

Safe

ty

Mainte

nanc

e

Relia

bility

Cost

Ease

of D

esign

Aesth

etics

Size

Weig

ht

Safe

ty

Mainte

nanc

e

Relia

bility

Ease

of D

esign

Safe

ty

Mainte

nanc

e

Relia

bility

Cost

Ease

of D

esign

Size

Safe

ty

Relia

bility

Cost x 9 4 9 9

Ease of Design 1 x 4 4 9

Safety 4 4 x 1 4

Maintenance 1 4 9 x 9

Reliability 1 1 4 1 x

0.08 0.20 0.23 0.16 0.34

Design Decisions

Control System

Decision Factors

Line

ar w

/ Spe

ed

Line

ar w

/ Voltage

Acce

l. Pr

ofile Decision

Factors

Fins

& Fan

s

Fans

Water

Jack

etDecision Factors

Deco

uplin

g Cap

acito

rs

Shielding

Dista

nce Ar

duino

Decision Factors

Exist

ing 4

8 V Bo

oster

24 V Boo

ster

Optio

nal A

C So

urce

Engineer

Andres 2.8 3.3 3.1

Austin 3.0 3.0 2.0

Charles 2.8 3.6 2.6

Leandra 3.1 2.3 3.2

Mitch 2.4 3.2 3.0

J osh 3.0 3.6 3.3

Weighted Scores 2.85 3.17 2.87

DC-DC Converter

Line

ar w

/ Spe

ed

Line

ar w

/ Voltage

Acce

l. Pr

ofile Decision

Factors

Fins

& Fan

s

Fans

Water

Jack

etDecision Factors

Deco

uplin

g Cap

acito

rs

Shielding

Dista

nce Ar

duino

Decision Factors

Exist

ing 4

8 V Bo

oster

24 V Boo

ster

Optio

nal A

C So

urce

Engineer

Andres 3.6 3.3 3.1

Charles 2.7 3.3 3.3

Mitch 3.4 3.0 2.6

Weighted Scores 3.23 3.20 3.00

Design Decisions (cont.)

Cooling System

Line

ar w

/ Spe

ed

Line

ar w

/ Voltage

Acce

l. Pr

ofile Decision

Factors

Fins

& Fan

s

Fans

Water

Jack

etDecision Factors

Deco

uplin

g Cap

acito

rs

Shielding

Dista

nce Ar

duino

Decision Factors

Exist

ing 4

8 V Bo

oster

24 V Boo

ster

Optio

nal A

C So

urce

Engineer

Austin 2.9 2.5 2.9

Leandra 3.8 3.2 2.5

J osh 2.9 2.7 2.8

Weighted Scores 3.20 2.80 2.73

Charging System

Line

ar w

/ Spe

ed

Line

ar w

/ Voltage

Acce

l. Pr

ofile Decision

Factors

Fins

& Fan

s

Fans

Water

Jack

etDecision Factors

Deco

uplin

g Cap

acito

rs

Shielding

Dista

nce Ar

duino

Decision Factors

Exist

ing 4

8 V Bo

oster

24 V Boo

ster

Optio

nal A

C So

urce

Engineer

Andres 3.6 3.5 2.4

Charles 3.0 2.7 3.2

Mitch 3.3 3.0 3.2

Weighted Scores 3.31 3.08 2.92

Final Design Decision

Primary Concept Secondary Concept

Control System Pedal press linear with voltage Pedal press linear with speed

DC-DC Converter Decoupling Capacitors between sources Shielding wires leading to Arduino

Cooling System Fins and fans Water jacket

Charging System 48 V booster 24 V booster

Questions?