energy storage technology, markets and applications

Ultracapacitors Microelectronics High-Voltage Capacitors 26 April 2007

Energy Storage Technology, Markets and Applications,

Ultracapacitor’s in Combination with Lithium-ion

Dr. John M. MillerMaxwell Technologies, Inc

IEEE Rock River Valley, IL, Section

Ultracapacitors Microelectronics High-Voltage Capacitors Slide 2

Abstract

Ultracapacitors are becoming widely accepted in the energy storage industry in both standalone and in combination with batteries. Standalone applications, once niche, are now rapidly expanding as the technical and economic benefits of this power dense component become more widely understood. Combination examples continue toproliferate, primarily in battery electric and hybrid electric commercial transportation segments such as transit buses and trains. The ultracapacitor offers a fast energy buffer to advanced chemistry energy reservoirs such as nickel metal hydride and lithium batteries and offer an opportunity for truly energy optimized battery systems. Thispresentation will discuss trends in energy storage systems, advanced chemistry batteries such as nickel-hydrogen and lithium-ion and why such components would benefit from working in combination with carbon capacitors.


Outline

• Primary Energy: Our Motivation• Ultracapacitor Energy Storage Mechanism

• Electrostatic vs. Electrochemical• Markets for Energy Storage Systems and 2007 Outlook

• Diverse, best applied where existing energy storage is low• Challenges for Lithium that Ultracapacitors Benefit

• Low temperature, high rates, long calendar & cycle life• Application Examples:

• Commercial, • Industrial, • Transportation

• Wrap-up


Source of all Primary Energy

• Solar radiation intercepted by earth’s disk is 178 PW(Tera = 1012, Peta = 1015, Exa = 1018)

178 PW

Solar

30% Albedo, or 52 PW reflected to space

32TW fromTerrestal(core)

3 TW tidalSun-moon-Earth interact

Of 178 PW, only 40 TW is absorbed into plantsGlobally.40 TW x 600 MYr => present fossil fuel supply


Where Does the Energy Go?

• Consider a 1 vehicle household in the U.S (equiv. gasoline)• Electricity consumption in average home = 1000 kWh/mo

• Vehicle having 25 mpg on average and 15,000mi/yr consumes:

• Total energy consumption of 1 vehicle household in U.S. in equivalent gasoline usage:

• = (2.941 + 2.06)= 5.00 metric tons of gasoline per household/year!

• Gasoline combusted generates ~3.14 kg CO2/kg• => 15.7 metric tons of CO2/household/year !

kggalkg

mpgmiVeh 206043.3

25000,15

=⎟⎟⎠

⎞⎜⎜⎝

⎛=>

kgMJ

gasolinekgh

scoaleffyrmo

mokWhHousehold 2941

2.43_3600

34.0_121000 =⎟

⎠⎞

⎜⎝⎛⎟⎠⎞

⎜⎝⎛⎟⎠⎞

⎜⎝⎛⎟⎟⎠

⎞⎜⎜⎝

⎛=>


Primary Energy Summary

• A single household with one vehicle consumes the equivalent of 5,000 kg of gasoline/year.• = 216 GJ of energy/household/year • 100M households consume 21.6 EJ

• U.S. energy supply breakdown (in Quad ~=EJ)• Coal…………22.6 • Gas….………23.1 • Oil……………40.6 • Nuclear……….8.2• Hydro…………2.7• Alternative……3.6

Total…………100 Quad = 104.5 EJ


What is going on ? Mega-trends

• Rising global awareness that we need more carbon free energy sources:• No viable non-carbon alternative can meet the energy demands of

1010 people in the near future, 2050.• Globally, 6.3B people, 12.8 TW (U.S. @ 25% =3.3 TW) now 28

TW in 2050• The right people are working on this, but have not been heard.

• Climate change is now positively linked to anthropogenic activities with very high confidence.• Net effect of human activity since 1750 has been one of warming.

• Hydrogen economy is a myth, will never happen! Yes, for niche applications.• Electricity from fuel cell costs 4x grid delivered electricity• It would take 400 Gen IV nuclear plants to equal hybridizing trans.

• Electricity is the energy carrier of the future.


What is an Ultracapacitor?• Invented in U.S. by Robert A. Rightmire of SOHIO

company.• U.S. Patent 3,288,641 “ELECTRICAL ENERGY STORAGE APPARATUS:

This invention relates generally to the utilization of an electrostatic field across the interphase boundary between an electron conductor and an ion conductor to promote the storage of energy by ionic adsorption at the interphase boundary.”Nov. 29, 1966

• Electrochemical storage batteries and capacitors have been in existence for over 200 years (Baghdad battery BC), Volta “pile” 1800, to Ben Franklin 1848 who coined the term “battery”.

• Battery stores energy in chemical bonds that follow reduction-oxidation (REDOX) reactions. Mass transfer is involved.

• Capacitors store energy in electrostatic fields between ions in solution and a material. No mass transfer involved – hence no electrochemcial wearout.

Source: Joel Schindall, “Concept and Status of Nano-sculpted Capacitor Battery,” Presented at 16th Annual Seminar on Double Layer Capacitors and Hybrid Energy Storage Devices December 4-6, Deerfield Beach, Florida


Ultracapacitor Material and Electrode• On cost of ultracapacitors is dominated

by carbon.• Raw material – coconut shells =>

• Carbon is the cost driver • Resin based – high purity, high mat’l costs• Natural product based – (coconut, wood,

coal, peat, etc.) lower cost, higher impurities

Grind

Activated carbon powderActivated carbon powder

Activation

Electrodefabrication

CoatingRolling/Kneading/Pasting

Source: Prof. Katsuhiko Naoi, Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology,Recent Advances in Capacitors and Hybrid Power Sources in Japan, presented to DOE Basic Energy Sciences Wkshp, 3-4 March 2007


Ions and Pores Model

• Pore sizes must be controlled to provide access for both ion species. AC

Conducting agents（ KB, AB ）

Al

Adsorped ions（anions, cations）

Solvents

Micro pores（ < 2 nm）

Meso pores（2 ~ 50 nm ）

Macro pores（ > 50 nm ）

CC

binder( PTFE )

Electrode for EDLC

Inset from: Prof. Katsuhiko Naoi, Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology,Recent Advances in Capacitors and Hybrid Power Sources in Japan,presented to DOE Basic Energy Sciences Wkshp, 3-4 March 2007


The Fundamentals

• Basics of the electronic double layer, i.e., ultracapacitor• An electronic charge accumulator having extreme capacitor plate specific

area and atomic scale charge separation distance.

Graphic: IEEE Spectrum, Jan 2005


Ultracapacitor Basics• The ultracapacitor model commonly applied is that of the series combination of two

DLC’s at the electrode - solvent compact layer.• The compact layer interface between the carbon particles and electrolyte ions,

the Helmholtz layer, is on the order of 1 atom thickness.

_ ++ _

Helmholtz layersSeparator

ElectrodeElectric conductivity

+_

++

++

_

_

_

_

_

_

+

++

+

ElectrodeElectric conductivity

ElectrolyteIonic conductivity

+_

+

+ +

+

__

_

_

++++++++

________

__

++_

Electrical Resistance:Collector foil +Foil to Carbon+C-particle toC-particle

Ionic ResistanceSeparator + electrolyte

Helmholtz layers


The Compact Layer• Evolution of electrochemical capacitor modeling theory:

• Helmholtz

• Gouy-Chapman

• Stern’s model

Helmholtz model:ε~78 for organic electrolyted~ 0.2nm for solvent moleculeC 340 uF/cm2, is 10x experimentC is not voltage dependent.

Known as the diffuseModel. Works well at low potential, over estimates C for higher potentials.

Improves on Gouy-Chapman by retaining Helmholtz compact layer of adsorbed ions and Gouy-Chapman diffuse layer of point charges, but modifies situation to include physical size to the ions.


Ultracapacitor Example• The model looks simple – but it could be tricky.• Consider:

• Carbon at 75 F/g (i.e., Farads of capacity per gram of carbon)• Total mass of carbon per device = 187g (as example)• Therefore: 75 (F/g)x 187g = 14,025 F (this is a huge number!)

• However:• Each unit consists of a pair of electrodes (1/2 total mass each)• AND 2 each electrode Double Layer Capacitors are in series.

_ _ ++Double Layer Cap Double Layer Cap

Ccell( )12

9

23

10*10

)(103

Scale

gm

dSC −==

εε

Ultra =


Ultracapacitor Example

• Completing the example.• Given that total Farads, Ftot = 14,025

FF

C

CCC

CCC

FC

totcell

e

CCCcell

tote

e

35064025,14

4

2

2

2121

21

===∴

=+

=

=

==

++Double Layer Cap Double Layer Cap

Ccell

CeCe


Ultracapacitor Cells

• Ultracapacitor cell design: Minimize ESR!• Trends are for ESR*C = τ <1s and PML 10 kW/kg

C = 650 1200 1500 2000 2600 3000 FESRac = 0.6 0.44 0.35 0.26 0.21 0.20 mΩESRdc = 0.8 0.58 0.47 0.35 0.31 0.30 mΩτ = 0.52 0.696 0.705 0.700 0.806 0.900 sIrms = 105 110 115 125 130 150+ Arms

Micro-Hybrid Industrial Applications Heavy Transportation


Maxwell’s Ultracapacitor Cell Model

• Electrical equivalent circuit model- Maxwell’s moment matched x-line• The three time constant model accounts for the highly distributed effects of

electrode “macro”, “meso” and “micro” pores.

#

C

Rtran1

#

C1

Rtran2 Rtran3

# C2

X Y

XY_LINT1X Y

XY_LINT2

X Y

XY_LINT3

0.4C(v 0.44C(v 0.16C(v

0.3R 0.2R 0.5R

mRsd

560 Ohm

Macro Meso Micro


Constant Current Efficiency of Ultracap

• Efficiency is dictated by materials (Umx, ESR) and Usage:• Efficiency, carbon loading, application requirements for SOC window.

• Ultracapacitor efficiency is partly owned by the manufacturer, and

• in part by the customer in terms ofapplication demands.

• The Maxwell ultracapacitor model accounts for electrode transmission line characteristic, C(U), and ESR(T,I)

⎥⎦

⎤⎢⎣

⎡⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎟⎠

⎞⎜⎜⎝

⎛+

=

⎟⎟⎠

⎞⎜⎜⎝

⎛

−−

+

=

xmx

c

MCI

Uxyxy

T

SOC

0

021

1

21

1)(ττ

η


Ultracapacitor Equivalent Circuit

• The Maxwell moment matched equivalent circuit model is used in this work.• Capacitance is SOC dependent: C(U) = Co + kuU• ESR = ESR(T,I) = Relectronic + Rionic

++Re Ri Re

C(U) C(U)

#

C

R1 Rtran1

#

C1

Rtran2 Rtran3

#

C2X YX Y

XY_LINT1X YX Y

XY_LINT2X YX Y

XY_LINT3

0.4C(v) 0.414C(v) 0.16C(v)

0.3R 0.2R 0.5R

Power MC2600-Cell Transmission Model

+ V

VM1

100

0.000018 Ohm

1.5 V

{ } )(02001

0)(1)( TTkTeRbTTRbTESR −−+−−= γ


Constant Power Model

• Analytical model and result• The result: 1st order, 2nd degree, nonlinear differential equation.

• Apply KVL and substitution ic = -CdU/dt yields for discharge case:

+C0

R

P0(t)

Uc(t) Uo(t)ic(t)

01

0

02 =++CP

UUU ccc ττ&&


Analytical Solution for CP Loading• Using this substitution plus some identities and a little algebra results in the

final expression for ultracapacitor internal voltage, Uc(t), under constant power loading:

• Two things to note:1. Under constant power, Po, the ultracapacitor internal voltage, Uc(t) cannot be

separated from time. 2. Time is now a parameter – hence the transcendental nature of the solution, and

the explicit relationship of ultracap internal potential with time.• However, this solution leads directly to the correct interpretation of ultracap

response to constant power loading:• Voltage – time (Uc(t),t) pairs exhibit squared, square root, and logarithmic inter-

relationships.

⎟⎟

⎠

⎞

⎜⎜

⎝

⎛ −++−−

−=

0

02

02

0

2

0 24)()(

ln4)(4

)()(4

11RP

RPtUtURPtU

RPtUtU

RPt cc

cc

cτ


Analytical Solution for CP Loading

• Illustration of constant power voltage and current• Measured

• Tf = 178.8s

• Analytical Result• Approx => time error!• ESR = Ro• C(U) = Co• tf = 184.4s• => small error!

Constant Power Voltage & Current

0

0.5

1

1.5

2

2.5

3

0 20 40 60 80 100 120 140 160 180 200

Time, s

Cel

l Pot

entia

l, V

-45-40-35-30-25-20-15-10-50510

Cel

l Cur

rent

, A

7.177)5.7(2)8.2(340

2

22

0

2

2

0

===

≅

PCU

t

CUtP

mxf

mxf

Constant Power Voltage & Current Modeled

0.000

0.500

1.000

1.500

2.000

2.500

3.000

0 20 40 60 80 100 120 140 160 180 200

Time, s

Cel

l Pot

entia

l, V

-45-40-35-30-25-20-15-10-50510

Cel

l Cur

rent

, A


Constant Power Efficiency

• Results for D Cell

D Cell Constant Power Efficiency

0.50.55

0.60.65

0.70.75

0.80.85

0.90.95

1

0 0.5 1 1.5 2 2.5 3Voltage, V

Ener

gy E

ffic

ienc

y c

ccd

dc

tPEtiRE

EE

00

20

0

1

==

−=η

d

ddd

dd

tPEtiRE

EE

00

20

0

1

1

==

+=η


Operating RangesRagone plot

10s100s1'000s

0.1 s

10'000s

0.0

0.1

1.0

10.0

100.0

1,000.0

1 10 100 1,000 10,000 100,000 1,000,000

Power density [W/kg]

Ener

gy d

ensi

ty [W

h/kg

]

PbNiMH

Li Ion

0.01s

ULTRACAPACITORS

1s

Film CAPACITORS

BATTERIESLarge Ultracaps

Small Ultracaps

Normal Range

Abuse ToleranceRapid discharge

The same for batteries


Ultracapacitors: Where to Next?• Fundamental need - understand solvent-salt structure and physical properties.• Performance - create a fundamental understanding of link between device

performance and bulk/interfacial molecular interactions.

• Develop new EDLC materials and architectures that will dramatically boost energy and power.

• Electrode materials with controlled pore size and surface area deposited in ordered geometries with intimate contact to current collectors

Excerpted from: Bruce Dunn, Yury Gogotri, Plenary Closing Session Remarks, DOE Basic Research Needs Workshop on Electrical Energy Storage, Washington, D.C., 4 April 2007


Markets for Energy Storage Systems

• Very diverse range of markets• Aerospace, industrial, transportation, utility, consumer electronics

• Energy Storage System (ESS) attributes• Regenerative braking and energy recuperation in bus, train, subway, etc. • Cold engine starting aide for standby power, UPS, truck, bus…• Burst power for wind turbine blade pitch systems, shipyard cranes,

material handling trucks, etc. • Bridge power for telecommunications, medical office, etc.• Voltage sag compensators for utility interconnects to restore voltage and to

smooth distribution voltage• Consumer applications in everything from camera’s, car audio, and cell

phones to fast heat coffee makers.• Virtually any application that demands high peak power.



Ford fuel cell concept vehicle

Honda FCX fuel cell vehicle

Saab biodiesel hybrid GM Autonomy fuel cell concept vehicle

ISE Hybrid Bus

Bombardier train

Toyota fuel cell concept with wheel motors

• More, and higher levels of electrification:• Cars, trucks, buses, trains…



Value today is in transportation, industrial and consumerTarget is the automotive market Hybrid drive trains, board net stabilization, distributed power

Fork lift, cranes

ApplicationMarket

AMR

UPS/Power quality

Telecom

Digital cameras, PDA’s, laptop, mobile phonesConsumer

Actuators (doors, valves etc.)

Pitch systemsIndustry

Buses

Trains, tramsTransportation


The Future of Transportation is Electric

• Vehicle applications for ultracapacitors are now beginning to emerge as ultracapacitor costs decrease below 1c/F.

• Vehicle PowerNet stabilization example is Alcoa-Maxwell APM• Micro-hybrid energy recuperation again, Alcoa-Maxwell APM• Strong hybrid propulsion and supporting subsystems

100F to 350F “C” and “D” sizeElectric steering, brakes, audioPowerNet stabilization

500F to 1000FBelt ISG, engine cold cranking,Micro hybrid recuperation

1000F to 4000F large cellsCI engine cold startingStrong hybrid energy storage


Challenges for Lithium that Ultracapacitors Benefit

• A value proposition must be made for the combination of ultracapacitors and lithium battery technology:• For a viable business case model, and• For application in mild, strong, and plug-in hybrids

Difficult algorithm for SOC, SOHEase of SOC and SOH monitoringLithium δSOC<50%Very wide SOC windowSensitive to rapid chg/dchgAbuse and rapid discharge tolerantEnergy mgm’t: Cell equalizationEnergy mgm’t: cell over voltageC<100 (at best)High power: C-rates >1000Moderate eff: 95% to 85%High efficiency: 98% to 92%-20oC to +40oC-40oC to +65oCElectrochemical, Faradaic deviceElectrostatic, non-Faradiac

BatteryUltracapacitor


Future Role of Ultracap’s in HEV & PHEV

• As merger of power dense component with energy dense component.• Technologies are complimentary.

SOC100%90%80%

30%20%

SOCWindowLi only

Goal SOC loadingLithium + UC Chevy Volt, eFlex

Lithium-ion packE = 16 kWhP = 136 kWSOCmx = 80%SOCmn = 30%Euseable = 8kWh


Lithium Technology Limitations

• Temperature and rate limits above 80% SOC• Temperature and rate limits below 30% SOC• PHEV’s and battery-EV require >70% SOC window

0 20 40 60 80 100State of charge (SOC)

D

C

ChargeRate

DischargeRate

Ultracapacitor

Lithium

State-of-charge Window, Theoretical ~70%

State-of-charge Window, Practical ~50%

Tail regions


Advanced Battery Characteristics

• Comparison of different cathode materials:(Vergleich unterschiedlicher Kathodenmarterialien)

Source: Andreas Jossen, “Lithium Akkumulatoren, -Grundlagen, aktuelle Entwicklungen, Einsatz –”Energiespeicher für Bordnetze und Antriebssysteme, Haus der Technik, Essen 14.02.2007


Lithium Cell Charge/Discharge Mgm’t• Charge and discharge rates must be managed in lithium.

Sicherheitsmanagement (Safety and security)

Source: Andreas Jossen, “Lithium Akkumulatoren, -Grundlagen, aktuelle Entwicklungen, Einsatz –”Energiespeicher für Bordnetze und Antriebssysteme, Haus der Technik, Essen 14.02.2007

Active circuit protectionPassive circuit protectionPassive cell component

Over chargeUnder chargeShort circuitOver temperature


Energy Storage System Roadmap• Lithium for energy storage systems continues to displace nickel metal

hydride technology. • Ultracapacitor technology must improve its cost picture – for energy, and

for energy throughput (Wh-cycles). AltairNano claim is <5x MXWL.

JCS 2.5*103 1.4x105

A123 5*103 2.8x105

AltairNano 15*103 8.4x105

750.5070Lithium

4*103

1.5x105750.6544NiMH

3*102

7x103800.1230VRLA

>106

4x1061216

(3000F cell at module level)

5Ultracap

Cycle Capability at 80% DOD# Cycles (Wh-cycles)

Power specific cost ($/kW)

Energy specific cost ($/Wh)

Specific Energy(Wh/kg)

ESS Component


DOE Perspective on Lithium Cost

Source: Tien Duong, “Research Needs: A Transportation Perspective – Applied Problems Can Be Addressed in a Fundamental Way,”Presented to Workshop on Basic Research Needs for Electrical Energy Storage, 2 April 2007, Washington, D.C.


Hybrid Energy Storage Systems• The new combination!

• The strengths of both.• High power density component plus• High energy density component


Lithium+Ultracapacitor Storage System

• The fast buffer and power cache branch must match or exceed the efficiency of lithium only:• Much higher matched load power than battery only• Far faster power delivery = low time constant of ultracap• High efficiency at higher power levels from ultracap

Energy ReservoirLithium Battery

Power CacheUltracapacitor

Fast bufferEMS Strategy

Hybrid Energy Storage System (HESS)

Power


Partitioning Power & Energy

Battery Pack

= Energy

UltraCap Pack=dynamics

Vehicle Loads

Characterize by timePdmx

Pcmx

Reference: Potential Ultracapacitor Roles for Hybrid Electric Vehicles Supercapacitor Seminar, 12/10/03Matthew Zolot, Tony Markel, Keith Wipke, and Ahmad Pesaran National Renewable Energy Laboratory

• Lithium pack with ultracapacitor combination


Defining the Opportunity

• Drive cycle determines peak charge and discharge power

cmx

dmx

dmxmnid

cmxmxic

PPr

RPUUUU

CQU

RPUUUU

=

−+==

=

++==

421

21

421

21

200

0

200

Pdmx

Pcmx

Uc(t)Umx

Uo

Umn

Ultracapacitor Voltage Swing

δSOCchg

δSOCdchg mnmx

mnmx

UrUUrUU

++

=22

0

Set initial state of charge (Uo) of the ultracapto match voltage swing (Pdmx/Pcmx)

Ref: Mark W. Verbrugge, Ping Liu, “Analytic Solutions and Experimental Data for Cyclic Voltammetry and Constant Power Operation of Capacitors Consistent with HEV Applications,” Journal of the Electrochemical Society, 153 (6) A1237-A1245 (200), pgs A1237 – A1245


Active Parallel Configuration

• Ultracapacitor energy flows controlled via energy management strategy to minimize battery cycling• Dc-dc converter efficiency at 96%• Ultracap efficiency must remain >95%• Converter plus ultracapacitor branch should maintain >92%

• Relative to matched load: 0.4PML for 1s, 0.25PML for 2s, 0.1PML for 8s

Batt

DLC"ultracapacitor"

PowerElectronicConverter

Active Parallel HESSCP Efficiency 3000F UC (0.1, 0.25, 0.4Pml)

0.40

0.50

0.60

0.70

0.80

0.90

1.00

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00Time, s

Eff


Illustration of Li Ion System for HEV

Reference: SAFT


Integrated Power Solutions

• Ultracapacitor and battery combinations are under investigation by MXWL and others.

• Architectures fall into either direct parallel or active parallel configurations.

BattDLC"ultracapacitor"

Passive Parallel HESS

Batt

DLC"ultracapacitor"

PowerElectronicConverter

Active Parallel HESS

Source: Prof. Juan Dixon EVS22 paper, Yokohama, Japan, Oct. 22-28 2006Originally developed and published by R. King, GE Global Research

Active parallel configuration being implemented by many investigators and companies


Ultracap’s in Combination with Batteries

• It is well known that ultracapacitors in combination with lead acid batteries improve performance and extend life.

• Recuperative systems (hybrid) are essentially battery –ultracapacitor combination systems and are available.• Siemens 14+x or Valeo StARS system.


Application Examples: Commercial

• Uninterruptible Power Supply

• Utility Voltage Restorer

• Wind Turbine


UPS demandsReliability for power back-up’sGraceful power downBackup power in emergency situationsShort term bridge power Short-term power as the transition is made to backup generation power

230 V, 50 HzDC Link 24 V Pb Battery BOOSTCAPTechnology 2*12 V, 7 Ah 10*650 FVolume [l] 2 2Weight [kg] 5 2Backup time 6 min 10 sLifetime [y] 2 10

RECTIFIER INVERTER

S-CAPSYSTEM

DC Link

SOURCE DRIVE

Power Quality and Power Reliability


ClearwellProtected

Loads~400 kW

Diesel Back-up1000 kW

Diesel Back-up750 kW

Palmdale Water District Power System

SCE UtilityGrid

Wind Turbine950 kW

Static switch

Water TreatmentPlant Loads

~500 kW

PQM

PQM

ClearwellOther Loads

~350 kW

Hydro250 kWHydro

250 kW

MM

ATS

PQMMM

EnergyBridge™ EB 450

MM

PQM

ATS

Utility meter

Power quality meter

Automatic transfer switch

Circuit breaker

Legend

Ultracapacitors

Power conversion

450 kW

EnergyBridgeTM UPS, Palmdale


One Line Diagram

SeriesInductance

Ls

FastSwitch

S1

BypassBreaker

CB3 (Optional)

IsolationBreaker

CB2

IsolationBreaker

CB1

BidirectionalInverter

BidirectionalDC to DCConverter

UltracapacitorBank

3

ToUtilityGrid

ToCriticalLoads

InductorL3

ElectrolyticCapacitor Bank

Sub-system 2: Shunt Power Conversion

Sub-system 1: Series Components

DSP Controller

EnergyBridgeTM UPS - One-line Diagram

Sub-system 3: Energy Storage

UPSUPS


Voltage Restorer System

Nominal voltage 800 V DC# of Ultracapacitors 640Energy stored 3 MJMax. power 263 kWOperational temperature –25 to 50 °C

System layout

Electronic Shock Absorber (ESA), an innovative grid stabilizing device


Wind Turbine Pitch Control Systems

Modern wind turbines consist of three-bladed variable speed turbines

Independent electro-mechanical propulsion units (pitch systems) control and adjust the rotor-blades for optimum power output

Latest technology uses the wind not only to produce wind energy but also for its own safety

To enhance the level of safety, each of the pitch systems is equipped with an emergency power supply


Case Studies: Wind Turbine

• Wind Turbine• Primarily in pitch control systems to

replace hydraulics

•• Telecommunications

• Mainly repeater tower local energy storage as bridge power for <2s outages

V90-3.0 MW wind turbine Vestas Wind Systems A/S; www.vestas.com

P o w e r c o n v e r s i o n & P o w e r t r a n s m i s s i o n

W i n d p o w e rP o w e r c o n v e r t e r

( o p t i o n a l )

M e c h a n i c a l p o w e r

P o w e r c o n v e r s i o n & c o n t r o l

P o w e r t r a n s m i s s i o n

S u p p l y g r i dR o t o rG e a r b o x

( o p t i o n a l )

E l e c t r i c a l P o w e r

P o w e r t r a n s f o r m e r

P o w e r c o n v e r s i o n & c o n t r o l

G e n e r a t o r

Graphic: Z. Chen, F. Blaaberg, Aalborg Univ., Institute for Energy Tech,Aalborg East, Denmark. IEEE Pwr Elect. Society Vol. 18, Nr. 3, 2006


Wind Turbine with Rotor Pitch

Rotor Blade

Hub

GearboxGenerator

Pitch Drive

Shaft

Yaw Motor


BOOSTCAP Backup Pitch Drive

Switchedmode power supply

Energystorage

Motor Inverter

AC Pitch Motor Turbine hub showing the three independent pitch systems


World’s Largest Wind Turbines

Ultracapacitor emergency power supply systems for MW class wind turbines using large ultracapacitors, e.g. 2700F cells

Enercon E-112 in Wilhelmshafen: First wind mill mounted with 4.5 MW• Rotor diameter 114 m• Hub height 124 m


Medium Size Wind TurbinesUltracapacitor emergency power supply systems for 250 kW to 2 MW class wind turbines using 350 F D cell ultracapacitors

Enercon E-48: Wind mill with 800 kW• Rotor diameter 48 m• Hub height 50 to 76 m


Market data

Economics of wind turbines~$5/MWh and $1.35/W installedTo date globally, $100B invested in 74 GW of capacity

Today>60’000 wind turbines operating worldwide74 GW of installed capacity<1% of the total world electricity supply

2012180 GW of installed capacity>2% of the total world electricity supplyMarket will be worth $150 billion US

2020Goal of 20% of the electricity supply covered by renewable energies


Application Examples: Industrial

• Material handling trucks• Trend from Pb-acid (3 packs) to hydrogen fuel cell

• Ship yard cranes• Opportunity for >30% emissions reductions from diesel gen sets• Downsized engine


Case Studies: Industrial

• Material handling trucks – forklift trucks

• Uninterruptible power supplies - UPS


Industrial Application: Forklift Truck

• Still Fork Truck Example• Drive motor: 15 kW• Lift motor: 20kW peak• Pb-acid battery base

• 80V 500Ah• 80V 775Ah• 80V 930Ah

• Battery pack mass• 1860 kg (4100#)• 2178 kg (4800#)

• Carrying capacity• 3500 kg R60-35• 4000 kg R60-40


General Hydrogen & Hydrogenics

Fuel Cell Power Pack fits existing Battery Space

Fuel Cell

Ultracapacitor Hybrid system

Radiator H2 Storage Tank 1.8kg at 5000 psi)

Class 1 Hydricity Pack


Application Examples: Transportation

• Heavy transportation• Transit bus• Shuttle vans• Refuse trucks

• Light commercial vehicles• Passenger car hybrids• Mild (Honda) and Strong (Toyota, Ford)• Power split architectures


Maxwell ProductsTransportation Ultracapacitor Applications

Gasoline Hybrid Bus Diesel Hybrid Bus

Hydrogen Fuel Cell BusHydrogen Hybrid Bus

Source: ISE Corporation, San Diego



• Hybrid transit bus (ISE)• 288 cell pack (144s x 2p) of 2600F, 2.7V cells• Max power 200 kW• Engine driven generator 175 kW

• 2002 - First ultracapacitor bus goes into revenue service in the US• Omnitrans in San Bernardino, CA

• Maximum speed: 62 mph• Maximum grade @ GVW: 18% w/o rollback• Acceleration @ GVW: 0 – 31mph : 17 sec




• Energy Flows

M1

M2CGB

Engine Fuel

GENMOT1

AUXMOT2

EnergyStorage

AC

GEN

M PS AIR

Accessories

ACCESSORIESSIEMENS ELFA SYSTEM

Inverter 1

Inverter 2

Air Conditioning Motor Power Steering Air Compressor

Generator

Motor 1

Motor 2

Auxiliary

400VAC

400VAC

230VAC

367-667VDC

AC/DC

230VAC Braking Resistors




• ISE Corporation – ThunderPack II• 0.324 kWh @ 360 Vdc• Assembled Pack

• 144 Maxwell BCAP0010 2600F cells in series.

• Tested pack ESR: 0.06 Ohm• Integrated cooling system• Integrated voltage, isolation, and

temperature monitoring• SAE J1939 communications

• Two Thunderpack II™ ultracapacitorpacks are connected in series.

• 0.12 Ohm tested ESR• 0.650 kWh stored energy at 720Vdc• 0.448 kWh usable energy



The Situation with Hybrids: CO2

• GHG emission reduction requires an overall reduction in fuel consumption.• Breaking 140 g/km CO2 is proving to be difficult

165165

186

140140

110

130

150

170

190

1996 2000 2004 2008 2012

CO2 (g/km)Total A.C.E.A Total A.C.E.A actualactual

A.C.E.A. selfA.C.E.A. self--commitmentcommitment

162162

Source: Renault

Hybrids notNeeded to reachACEA goal

Hybrids are Necessary to makeFurther progress

(4.37 T/yr)

(3.71 T/yr)

Demands 25%CO2 reduction

OEM Goal is120 g/km


How Much Fuel Can be Saved?• Hybrid functions:

• Stop/start (non-idling for reduction of CO2)

• Launch and boost (acceleration assist)

• Regenerative braking (subject of hybrid tax credit)

• Electric only range (may incur additional incentives)

Stop/Start

Regen

Loads

Wgt

% Improvement

14V (12V) 42V (36V) 150V (144V) 330V (288V) Conventional PowerNet Mild Hybrid Full Hybrid

Base Veh Crankshaft IMA THS& Belt ISG ISG

Generator Efficiency Improvements

Idle/Stop/Start

Soft boost/recuperation

Energy recuperation

Acceleration support

Energy recuperation

Electric onlyrange

High Voltage SystemsIsolation Requirements

Fuel economy gains from idle-stop (drive cycle dependent) and Regeneration (drive cycle, electric power rating, and efficiencydependent)

In the strong hybrid regeneration is >30% FE improvement due to higher power levels and greater efficiency (higher voltages).

Fuel economy loss from electrical loads (PowerNet) and incrementalVehicle weight incurred from hybridizing (generally the battery).

Electrical loads ( x Watts/ y% FE loss)Weight (+10% weight/-8% FE loss)

3% to 7%

5% micro hybrid, 8% to 13% mild hybrid


Strong Hybrid Ultracap Application

• Power flows are computed for a selected engine control strategy:• Engine strategy is fixed for both moderate and aggressive drive cycles• Energy management strategy of battery + ultracapacitor

• Battery supports auxiliary electrical loads: base + electric steering + eA/C• Ultracapacitor is the focal point of driveline power flows• Ultracapacitor energy is circulated to maintain battery per EMS strategy

Atkinson cycle I4110 kW with torsion damper

Chain drive of HSD replacedWith gear drive train

Est. 4.05:1 final driveIPM GeneratorMG1 est. 30 kW

IPM Traction MotorMG2 est. 50kW

Engine driven O/P

Compound Planetary

Source: David Hermance, SAE Hybrid Symposium 2006


eCVT Operational Strategy

• Engine power in the eCVT splits into an electric path and a direct mechanical path to the wheels.

R

C1 C2

S1 S2

ICE

M/G1 M/G2

RX400h SUV Hybrid

400 kW V8

109 kW Gen 123 kW Motor

FD

Batt

45 kW Battery& Converter

Pg

Pb

Pg+Pb

PePe-Pg

Pg+Pb

Pe+Pb

DualPlanetary

Total Engine

Generator

EngineDirect toWheels

Battery

P

Pow

er

TractionMotor

Tota

l Driv

e Po

wer

Power Split eCVTPower Flows

PePg

Pb

PmPe-Pg

Pe+Pb

Example of motor speed requirements:Vehicle speed, V = 97 mph and rw = 0.332m given Gfd=4.05Planetary gear E2 has k2 = 2.478 therefore:Ωmg2 = k2*Gfd*V/rw = 1310 rad/s (12,518 rpm)If V=147mph (autobahn) Ωmg2 = 1986 rad/s (18,971 rpm)

Note: WOT speed is 112 mph N.A. and124 mph Autobahn,via longer FD on RX400h.


Power Split Hybrid System Evaluated

• RX 400h SUV• Needs are:• Engine damper• Engine driven oil

pump via through shaft

• Gear vs chain to final drive

• Compound planetary

• GS450h• Hybrid sequential

shift-matic single mode eCVT

• Simple input planetary and Ravigneauxoutput

• High: 1.9:1• Low: 3.9:1• L110 eCVT mass is

132 kg

Excerpt from Dr. Takehisa Yaegashi Int’l Wkshp on HEV, Seoul, Korea Aug. 19, 2005


Strong Hybrids

• Available today

• Ford Escape Hybrid Toyota RX400h Toyota Prius-II• 2.3L L4 99 kW 3.0L V6 1.5L L4 57 kW• 330V 70 kW motor 650V 123 kW motor 500V 50 kW motor• 5.5 Ah 250 cell(Sanyo) 6.5 Ah 240 cell (Panasonic) 6.5 Ah 168 cell• Tz60 = 11.5 s 7.4 s 10.5 s


Permanent Reluctance Motor (PRM)

• Toyota hybrid power split motor of choice• MG1: 0.5 kg NdFeB• MG2: 1.0 kg NdFeB

• Manufacturing constraints• All in line high tolerance

• Operational constraints• OC, OT demag• Magnet retention at high

speeds• Prius I: 5,000 rpm• Prius II: 6,500 rpm• RX400h: 12,400 rpm• Camry: 14,500 rpm

Photo courtesy ofJ-N-J Miller, PLC

Clear Trend Up


Lexus LS600h

• $104,715 tag on the hybrid version• 2295 kg curb, 21 mpg M-H• Engine: 5.0liter V8, 290 kW, 522 Nm• Electrics: eCVT 165 kW traction motor, 650V• Battery: 288V, 36kWpk, 30kW cont. NiMH• Propulsion power: 347 kW total

Single mode eCVT


Toyota Hybrid Vehicle Trends

• Toyota is the industry leader in high power density permanent magnet electric machines.

8.95.27.310.512.5stz60650650650500274VSystem244288288201.6274V~2536362121kW3045452525kW*Battery

140/6000218/6000155/560057/500052/4500kW/rpm2.4 L43.5 V63.3 V61.5 L41.1 L4LitersEngine2006.52006.2200520031997CYYear intro

CamryGS450hRX400hPrius, THS-IIPrius THS-IUnitsComponent

Trend #1: Continuous increase in system voltage for reduced power electronics cost.Trend #2: Battery terminal potentials converging to 220V to 240V


Toyota Hybrid Vehicle Trends

• Toyota leads industry in electric machine power density nearing 4 kW/kg

Resin injectionAdhesive retention, gravity dripPM ret.1402541917873kWMax Pwr

13,00013,000+13,00010,0006000Rpm~601341092912kWMG1

14,50014,40012,40065005600Rpm

2700-1500

2750-3840

3330-1500

4000-1200

3500-400

Nmrpm

1054500

1475600-13,000

1234500

501200-1500

331040-5600

kWrpm

MG2

650650650500274VSystemCamryGS450hRX400hPrius, THS-IIPrius THS-IUnitsComponent

Trend #3: dramatic increase in M-G power without increase inPermanent Magnet mass. Still ~1.0kg MG2 and ~0.5kg MG1


Revival of the Batt-EV

• Tesla and Phoenix Motors are pioneering a new wave of electrics.• Roadster @ $92,000 each (381 sold)• 1180 kg (394kg battery)• Tz60 < 4s• MG1 185kW into 2spd transmission• Vwot = 210 kph• Battery: 400 km AER, 3.5h recharg• 200,000km life (5 yrs)

• White Star• 4 seater MY2010• $50,000 each


Ultracapacitor’s are about Power!

When it absolutely, positivelymust respond fast ---

This helps


Maxwell TechnologiesThe Ultracapacitor Company

Thank You!


… and what can Ultracaps do to your car???

Photo courtesy ofhttp://www.techeblog.com/index.php/tech-gadget/street-legal-jet-powered-vw-beetle

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