Z A C H M I C H E L , J O N A T H A N S C I S L O WJ A M I E O T T M A R , W E N X I A O Z E N G

HYBRID FORMULA CARSD1115

PROBLEM: CRUDE OIL DEPENDENCY

• The United States is responsible for 25% of the world’s oil consumption

• Major contribution to pollution• 1000 barrels of crude oil extracted every second

• Info from: http://www.oildependency.org/

SOLUTION: HYBRID VEHICLES

• Electric vehicles are a greener alternative• Inconvenience of charging• Technology has come a long way• Hybrid alternatives allow for less pollution while

still having an IC engine

FORMULA HYBRID

Formula Hybrid™ is a design and engineering challenge for undergraduate and graduate college and university students. They must design, build, and compete an open-wheel, single-seat, electric or plug-in hybrid-electric racecar. This car must conform to a formula which emphasizes drive train innovation and fuel efficiency in a high-performance application.

FORMULA HYBRID INTERNATIONAL COMPETITION

• The Society of Automotive Engineers (SAE) established the Formula Hybrid competition in 2006, with the 1st competition held in 2007 featuring only 6 universities• As of December 6, 2011, 27 teams from 3

countries are registered to compete in the 2012 competition.

JUDGED EVENTS

Dynamic Events• Acceleration Runs (electric & unrestricted)

– 75 points each• AutoCross

– 150 points• Endurance Run

– 400 Points

Static Events• Presentation

– 100 points• Design

– 200 points

COMPETITION DESIGN CONSTRAINTS

Design restrictions include:• Each vehicle is allotted 19.5 Mega Joules of

energy (Fuel and Accumulators combined)• Teams cannot spend more than $7,200 on

accumulators (batteries, super-capacitors, etc.)• Other design constraints are also involved for

safety and other reasons

DRIVETRAIN CONFIGURATIONPARALLEL VS. SERIES

Series

• Electric motor provides all power to the wheels.

• Power is received from batteries or a generator driven by a gas engine.

• Batteries may be recharged by generator and regenerative breaking.

• Advantages• Simplest hybrid configuration• Requires small IC engine• Works well in stop-and-go

conditions

• Disadvantages• Requires larger battery capacity

and electric motor.• Expensive configuration

DRIVETRAIN CONFIGURATIONPARALLEL VS. SERIES

• Gas engine and electric motor power the wheels.

• Engine is connected directly to wheels, eliminating inefficient energy conversion

• May use regenerative braking to charge batteries

• Advantages• Requires smaller battery capacity• Eliminates inefficient energy loss• Works well in highway condition

• Disadvantages• Inefficient in stop-and-go

situations.

Parallel

DRIVETRAIN CONFIGURATIONPARALLEL VS. SERIES

• Combines advantages of series and parallel setup.

• Gas engine can directly drive wheels or be disconnected.

• Advantages• Maximum efficiency• Flexibility

• Disadvantages• Computer system is much more

complex.• Requires large battery back and a

generator, which results in a very expensive system

Series-Parallel

3-PHASE AC INDUCTION MOTOR

• Power is supplied to rotor by electromagnetic induction• Speed is easily

controlled• Simple motor setup• High power availability• Smooth power and

control• Generally have lowest

cost among electric motors

AC – 15 ELECTRIC MOTOR

• Manufactured by HPEVS and purchased from Thunderstruck Motors

A CLOSER LOOK

CURTIS 1238R MOTOR CONTROLLER

• Tennant offered to donate a motor controller• The Curtis 1238R was the only controller which

was able to handle the high current requirements• Programmed using Vehicle Control Language• Curtis 1311 Handheld programmer included

CURTIS 1238R CONTINUED

• The Curtis 1238R is able to operate in torque control mode• Perfect for parallel hybrid configuration•Designed for 72-96V systems• 2 minute RMS current rating – 550A•Meets IP65 environmental sealing standard

CURTIS 1238R CONTINUED

BATTERY CHEMISTRY

Lithium-Ion• Very reliable• Can handle high

amounts of current• Ideal for powering

electric motors• Heavier than

lithium-polymer

Lithium-Polymer• Can handle even

more current than lithium-ion• Lightweight• Cheaper cells• Less reliable• Complex charging• Unstable

LITHIUM-ION BATTERIES

• Rechargeable prismatic cells• Reduces cost and

complexity• Safer than other

lithium based batteries• High energy density • Handle high current• Chose to go with

LiFePO4 chemistry

MOLECULAR STRUCTURE

• Molecular formula: LiFePO4

• Li has +1 valence charge• Fe has +2 valence charge• PO4 has -3 valence charge• Used as cathode material in lithium-ion batteries• Inexpensive, non-toxic, and environmentally

friendly• Requires less intense charge monitoring• Slightly lower energy density than other lithium

ion chemistries

BATTERY COMPANIES/DISTRIBUTORS

CONSIDERED

•Flux Power•Thundersky•Calib Power•Valence

•Dow Kokam•LifeBatt•Evolve Electrics•The Battery Shop

FLUX POWER 3.2V 40AH CELLS

• Current:• 400 A Impulse (2 sec)• 200 A Peak (10 sec)• 120 A Continuous

• Voltage:• 3.9 V Maximum• 3.2 V Nominal• 2.5 V Minimum

These batteries can handle all the necessary current requirements for our electric motor, including the momentary initial 300 A discharge.

FLUX POWER 3.2V 40AH CELLS

• High energy density• Ideal for Electric Vehicles• Low internal impedance• 100% factory tested• Rigid plastic exterior• Operating Temperature: -45 to +85

(Celsius)• Expected >5000 cycle life at 70%

discharge

DETERMINING BATTERY CAPACITY

As previously stated, the competition allows each vehicle to have 19.5 Mega Joules of energy onboard. We chose 40Ah cells so the electric portion of total onboard energy is around 40%, allowing us to use more gas for the IC engine.

Joules (J) = (voltage)(battery capacity)(.8)(3600)

Our System:(72 V)(40 Ah)(.8)(3600) = 8.294 MJ 8.294 MJ/19.5 MJ = 42.5% Electric

BATTERY PERFORMANCE

• Able to hold charge well

• At a rate of 1C the batteries will last for over an hour

1C*40Ah = 40A• At a rate of 3C they will last just under 20 minutes

3C*40Ah = 120A

CHARGER

• Delta-Q QuiQ Charger• 1kW Unit• 72V DC output• Max of 100V DC• Universal input (85-265 AC)• 12A charging current• UL compliant• Can be programmed for a wide variety of battery types

CHARGER CONTINUED

• Uses high efficiency, high frequency switching circuit• Digital software control• Housed in fully-sealed enclosure• Can be used onboard vehicle• Safety and reliability are a major design concern

ACCUMULATOR MONITORING SYSTEM

• Required in Formula Hybrid rules• Must be active when car is running or

charging• Automatically take action to prevent

conditions such as over charge and over temperature • Disable HV system under conditions such

as over voltage, under voltage, cell reversal, and over temperature

AMS CONTINUED

•Must remain disabled until manually reset (reset button must not be accessible to driver)• Balancing is a mechanism to equalize state of charge or cell voltage• Bimetallic thermal switches provide over temperature protection

BATTERY MANAGEMENT SYSTEM

Lithiumate Lite Li-Ion BMS for EV conversions

BMS CONTINUED

Lithiumate Lite• Designed specifically for EV conversions • Distributed: cell boards mounted on cells, single

wire to adjacent cell boards • For large packs: up to 160 cells (~ 500 V), in up to 8

banks • Supports all cell form factors, and most Lithium

chemistries • Protects cells from over current, under/over voltage,

under/over temperature • Compatible with most chargers and most motor

drivers

BMS CONTINUED

Measurement •Measures and reports the cell voltages and temperatures in up to 8 banks of cells in a battery pack •Measures and reports the battery pack current (bidirectional load current up to 900 A; charger current up to 30 A)

BMS CONTINUED

Evaluation • Calculates and reports the State Of Charge

of the battery pack

Management • Balances the pack • Passive balancing • Voltage remains balanced for each cell

BMS CONTINUED

Protection • Turns off charger if any cell voltage exceeds

a maximum, or the charging current is excessive • Requests a reduction of motor drive if the

battery is nearly empty • Requests that motor controller be turned off

if any cell voltage drops below a minimum, or the discharging current is excessive

BMS CONTINUED

Protection • Disables charging and/or discharging if

any cell's temperature is outside a specified range • Disables charging and discharging if any

cell board or bank stops reporting • Prevents driving off when the vehicle is

still plugged into the AC outlet

BMS CONTINUED

ELECTRICAL SYSTEM OVERVIEW

• Three-Phase AC Induction Electric Motor• HPEVs AC-15

• Motor Controller• Curtis 1238R

• Handheld Programmer• Curtis 1311

• 24 3.2V LiFePO4 Battery Cells • Flux Power

• 72V Charger• Delta-Q

• Lithiumate Lite Battery Management System• Elithion

• HPEVs AC-15 Electric Motor was ordered from Thunderstruck Motors

• This is in and ready to use

• Curtis 1238R Motor Controller and 1311 handheld programmer donated by Tennant

• These are in and ready to use

PROJECT STATUS

• 24 3.2V LiFePO4 Cells on order from Flux Power

• These should be in and ready to use early next semester

• DeltaQ 72V charger on order from Flux Power

• This should be in and ready to use early next semester

PROJECT STATUS CONTINUED

PROJECT STATUS CONTINUED

• Lithiumate Lite Battery Management system on order from Elithion• This should be in and ready to use early next

semester

TASKS REMAINING

• Wait for batteries to come in• Get additional wiring etc. necessary• Get the Battery Management System working• Connect all of the main components• Get the motor running• Program the motor• Get everything onboard a test vehicle (if we do

bench testing first)• Make adjustments as necessary

TIMELINE

TaskEstimated Date of Completion

Wait for batteries

Hopefully these will be in by the

start of the semester

Get additional wiring, etc. End of January

Finish work on BMS End of February

Connect everything up End of March

Have motor running End of April

Program motor and get everything onboard the

vehicleEnd of May

Make adjustments as necessary

Ongoing until the end of the semester

• Everything will be pushed back if batteries take longer to come (this will be beyond our control)

• It’s very difficult to estimate how long each part will take since we haven’t been able to work with the components yet

• Gave a good amount of time for each part while ensuring the project is finished

• Tasks may take more or less time

• Getting it onboard a vehicle will depend on the Mechanical Engineering team

• No tasks are split up individually since we can and will work as a team on every aspect

UPDATED BUDGET

Part Cost per unit Quantity Total Cost Notes

Electric Motor Controller – Curtis

1238R$1,500 1 0 (Donated)

Donated by Bob Erko from Tennant

Curtis 1311 Motor Controller

Programmer$755 1 0 (Donated)

Also donated by Bob Erko from Tennant

AC Induction Motor (AC-15)

$1,350 1 $1,350Purchased from

Thunderstruck MotorsOn ME budget

Flux Power 3.2V 40Ah Cells

$54.48 24 $1,307.52Purchased direct from

Flux PowerDelta-Q 72V 1kW

Charger$382.86 1 $382.86

Also purchased from Flux Power

eLithion Lithiumate Lite

Battery Management

System

$481 1 $481Purchased through EVolveElectrics.com

Miscellaneous Wiring/Emergency Switches/Safety

~300.00 NA ~300.00We will need various

additional parts for the electrical system.

FINANCIAL OUTLOOK

Our Senior Design budget $400

Remaining Mechanical Engineering Senior Design Team budget $1017

Donation from Phoenix International $2500

Batteries, Charger, and BMSNote: Tax and shipping not included -$2171.38

TOTAL BUDGET REMAINING $1745.62

Items still needed to be purchasedNote: This only includes electrical and the budget will be used for the whole project as

needed

~$300

SUMMARY SLIDE

• We have made very good progress• Despite a limited budget and difficulties in

dealing with companies we have gotten all of the major components required• Batteries will be ordered and in by next semester• Won’t be in competition until next year due to

mechanical problems• Our design requirements remain unchanged• On track to finish our portion of the overall project

IMAGE CREDIT

• http://www.oildependency.org/• http://www.newsmania.com/wp-content/uploads/2011/08/crude-oil-300x293.jpg• http://www.renewableenergyworld.com/assets/images/story/2010/7/30/1332-top-

five-electric-vehicle-developments.jpg• http://upload.wikimedia.org/wikipedia/commons/thumb/e/ed/

Toyota_Prius_III_20090710_front.JPG/250px-Toyota_Prius_III_20090710_front.JPG• http://www.ndspe.org/news/Summer3.jpg• http://www.ndsu.edu/me/sae/images/webformula.jpg• http://www.ndsu.edu/me/sae/images/Formula-Car-1.jpg• http://www.ndsu.edu/me/sae/images/Formula-Car-2.jpg• http://www.nhms.com/images/_03C4015_lg.jpg• http://kelvinslush.com/wp-content/uploads/2010/09/TheRules_Kelvin-480x296.jpg• http://www.melaniewilson.org/.a/6a00d8354abaaa53ef014e88f34393970d-800wi• http://www.toyota-global.com/innovation/environmental_technology/

technology_file/• Image from Tennant presentation

IMAGE CREDIT CONTINUED

• http://hpevs.com/nev/ac-15• Image from Mechanical Engineering design team• http://evolveelectrics.com/PDF/AC%20Motor%20Kit/Curtis_1238_Controller.pdf• http://fluxpwr.com/products/3-2v-cell/• http://upload.wikimedia.org/wikipedia/commons/1/15/Lithium_iron_phosphateV2.png• http://fluxpwr.com/• http://fluxpwr.com/wp-content/pdf/flux_PB_cell_11_21_WEB.pdf• http://www.delta-q.com/products/images/QuiQ-dci_AC_inputcopy_000.jpg• http://www.delta-q.com/products/720-0001_Rev-5_QuiQ_Data_Sheet_compact.pdf• http://elithion.com/img/lithiumate_lite.jpg• http://elithion.com/img/lite_block_charger.jpg• http://www.nappepin.com/LithiumHawk/AC31_01.png• http://evolveelectrics.com/PDF/AC%20Motor%20Kit/Curtis_1238_Controller.pdf• http://fluxpwr.com/products/3-2v-cell/• http://www.delta-q.com/products/images/QuiQ-dci_AC_inputcopy_000.jpg• http://elithion.com/img/lithiumate_lite.jpg• http://elithion.com/img/lite_application.jpg

QUESTIONS?