Miniscale Energy Miniscale Energy GenerationGeneration

Peter C. Gravelle, Borce Gorevski, Peter C. Gravelle, Borce Gorevski, Nick IevaNick Ieva

Sponsor/Advisor: Dr. S. Lyshevski, Sponsor/Advisor: Dr. S. Lyshevski, Electrical Engineering Electrical Engineering

DepartmentDepartment

The TeamThe Team

Left to Right:Left to Right:Nick Ieva, Peter C. Gravelle , Borce Nick Ieva, Peter C. Gravelle , Borce GorevskiGorevskiAdvisor/Sponsor: Dr. S LyshevskiAdvisor/Sponsor: Dr. S Lyshevski

ObjectiveObjective

To design and prototype a self-To design and prototype a self-sufficient mini-scale generator.sufficient mini-scale generator.

Block Diagram/RoadmapBlock Diagram/Roadmap

Velocity of Water

Angular velocity of

turbine

Velocity of magnets over

windings

Current in windings

(AC)

Rectifier (AC-DC)

Is voltage

too high?

Zener diode burns excess

energy

Yes

Store in supercapacitor

NoDC-DC

conversion (increase voltage)

Load

GoalsGoals

Sub-20 cmSub-20 cm33 volume volume At least 0.1 W/cmAt least 0.1 W/cm33

We want to exceed theseWe want to exceed these Turbine (Runner) with permanent Turbine (Runner) with permanent

magnetsmagnets Salt-water resistant (nautical/sharks)Salt-water resistant (nautical/sharks)

Output voltage greater than 7VOutput voltage greater than 7V

Design ChoicesDesign Choices

GeneratorGenerator TurbineTurbine MagnetsMagnets WindingsWindings

ElectronicsElectronics Energy storageEnergy storage Energy harvesting circuitryEnergy harvesting circuitry

HousingHousing

TurbineTurbine

PeltonPelton Turbine Turbine FrancisFrancis Turbine Turbine

We Picked a Pelton-like We Picked a Pelton-like wheelwheel

Technical Details: Technical Details: TurbineTurbine

Diameter of turbine: <2.5cmDiameter of turbine: <2.5cm Material: plasticMaterial: plastic

Nylon (reinforced or not?)Nylon (reinforced or not?) Magnets mounted on wheel using Magnets mounted on wheel using

water-proof epoxy.water-proof epoxy.

MagnetsMagnets

SmCoSmCo Corrosion resistantCorrosion resistant More expensiveMore expensive WeakerWeaker

NdFeBNdFeB Very highly magneticVery highly magnetic Low costLow cost Very corrodibleVery corrodible

Magnet Feasibility GraphMagnet Feasibility Graph

Humidity Resistance Field Strength Salt Environment Small Pieces Cost

T1 T2 T T4 E1 sm

NdFeB 1 3 1 3 3 11

SmCo 3 2 3 1 1 10

Feasibility Chart: Magnets

0

1

2

3T1

T2

T3T4

E1

NdFeB

SmCo

We’re using NdFeBWe’re using NdFeB

Dr. Lyshevski recommended itDr. Lyshevski recommended it CheaperCheaper StrongerStronger More easily machined into small partsMore easily machined into small parts

Small arcs required for our designSmall arcs required for our design Corrosion can be dealt with by plastic Corrosion can be dealt with by plastic

coatingcoating Right now looking at ring magnets with OD Right now looking at ring magnets with OD

= 0.625”, ID = 0.250”, and thickness of = 0.625”, ID = 0.250”, and thickness of either 0.250” or 0.375”either 0.250” or 0.375”

Field Simulation for N35 Field Simulation for N35 grade NdFeB (3mm dia, grade NdFeB (3mm dia,

1mm thick disc)1mm thick disc)

Dens ity P lot: |B |, Tes la

6.942e-001 : > 7.279e-0016.605e-001 : 6.942e-0016.268e-001 : 6.605e-0015.931e-001 : 6.268e-0015.594e-001 : 5.931e-0015.257e-001 : 5.594e-0014.920e-001 : 5.257e-0014.583e-001 : 4.920e-0014.246e-001 : 4.583e-0013.909e-001 : 4.246e-0013.572e-001 : 3.909e-0013.235e-001 : 3.572e-0012.898e-001 : 3.235e-0012.561e-001 : 2.898e-0012.224e-001 : 2.561e-0011.887e-001 : 2.224e-0011.550e-001 : 1.887e-0011.213e-001 : 1.550e-0018.759e-002 : 1.213e-001< 5.389e-002 : 8.759e-002

WindingsWindings

Winding wire will be supplied by Dr. Winding wire will be supplied by Dr. Lyshevski Lyshevski

Axial motor winding patternAxial motor winding pattern Pattern will be made of plastic (see Pattern will be made of plastic (see

below)below)

Energy StorageEnergy Storage BatteriesBatteries

High energy densityHigh energy density Limited charge cyclesLimited charge cycles Lower voltageLower voltage Temperature sensitivityTemperature sensitivity

SupercapacitorsSupercapacitors High (but lower than batteries) energy densityHigh (but lower than batteries) energy density Unlimited charge cyclesUnlimited charge cycles Higher voltageHigher voltage Temperature insensitive ( -40C to 70C)Temperature insensitive ( -40C to 70C)

Batteries vs. Batteries vs. SupercapacitorsSupercapacitorsFeasibility Assessment: Energy Storage

0

1

2

3T1

T2

T3

T4

T5

T6

T7

T8

S1

E1 Li-ion BatteriesSupercapacitors

EnergyDensity

Power Density Size

Max Voltage Life

Charging Discharging

CircuitOperating

Temp Self-DischargeH2O

Safety Cost

T1 T2 T3 T4 T5 T6 T7 T8 S1 E1 sum

Li-ion Batteries 3 1 1 1 1 1 2 3 1 1 15

Supercapacitors 2 3 3 3 3 3 3 1 3 1 25

We picked We picked SupercapacitorsSupercapacitors

Smaller sizeSmaller size Greater cycle lifeGreater cycle life Will not ignite in waterWill not ignite in water Greater power densityGreater power density High voltage densityHigh voltage density

Feasibility for Feasibility for SupercapacitorsSupercapacitors

 Capacit

anceNom.

VoltageMax

Current Size ESR  Row Total

Column Total

Row + Column

Relative Weights

Capacitance   \ - \ \   1.5   1.5 0.2

Nom. Voltage     \ \ | 1 0.5 1.5 0.2

Max Current       | | 0 0.5 0.5 0.066667

Size         - 1 2 3 0.4

ESR               1 1 0.133333

Sum 7.5 1

Feasibility for Super Feasibility for Super CapacitorsCapacitors

Rel

ativ

e W

eig

hts

HP

SK

0G10

3ZL

(fl

at)

FS

0H22

3Z (

cyl)

FS

0H47

3Z (

cyl)

FT

0H10

4Z (

cyl)

FT

0H22

4Z (

cyl)

FA

0H47

3Z (

cyl)

FE

0H47

3Z (

cyl)

FE

0H10

4Z (

cyl)

PC

5 (f

lat)

PC

5-5

(fla

t)

GW

2 1

3D (

flat

)

B49

100A

1503

Q00

0 (f

lat)

B49

100B

1104

Q00

0 (f

lat)

Capacitance 0.2 1 1 2 3 3 2 2 3 5 4 4 4 5Nom. Voltage 0.2 3 5 5 5 5 5 5 5 2 4 4 1 1Max Current 0.066667 5 3 3 3 3 5 5 5 5 5 5 4 5

Size 0.4 4 5 5 5 4 3 4 3 2 0 1 2 1ESR 0.133333 1 2 2 3 3 3 3 4 5 5 5 5 5Sum 2.866667 3.666667 3.866667 4.2 3.8 3.333333 3.733333 3.666667 3.2 2.6 3 2.733333 2.6

Normalized Sum 0.68254 0.873016 0.920635 1 0.904762 0.793651 0.888889 0.873016 0.761905 0.619048 0.714286 0.650794 0.619048

Energy Harvesting: AC-Energy Harvesting: AC-DCDC

Standard bridge rectifierStandard bridge rectifier Takes AC input and turns it into DC Takes AC input and turns it into DC

outputoutput We will be using a capacitor for We will be using a capacitor for

additional smoothingadditional smoothing

Harvesting Circuitry: Harvesting Circuitry: Voltage RegulationVoltage Regulation

Switched-capacitor DC-DC voltage converterSwitched-capacitor DC-DC voltage converter Efficiency: 88-96%Efficiency: 88-96% Doubles input voltageDoubles input voltage Max output current: 200mAMax output current: 200mA

Step-up (boost) converterStep-up (boost) converter Has an efficiency of 60-90%Has an efficiency of 60-90% But needs more parts (volume, cost)But needs more parts (volume, cost) Adjustable output voltage/currentAdjustable output voltage/current More robustMore robust

Voltage/thermal/current protectionsVoltage/thermal/current protections Max output current: 1AMax output current: 1A

Voltage Conversion Feasibility

0

0.5

1

1.5

2

2.5

3T1

T2

T3

T4T5

T6

T7

Switched Capacitor

Boost Conversion

EaseOf

Design Efficiency Tunable RobustMax

CurrentOperating

temperature EMI Volume

T1 T2 T3 T4 T5 T6 T7 T8 sum

SwitchedCapacitor 3 3 1 1 1 2 3 3 17

BoostConversion 1 1 3 3 3 3 1 1 16

Housing DesignHousing Design

House DesignHouse Design

This This cylindrical cylindrical casing was casing was designed so designed so we can save we can save on volumeon volume

Housing DesignHousing DesignOur final design has Our final design has

the codename: the codename: Windmill -please Windmill -please note the extended note the extended shaftshaft

The idea came from a The idea came from a meeting with Dr. meeting with Dr. LyshevskiLyshevski

Questions and CommentsQuestions and Comments