PHEV TestingSAE J1711-revision

Session 2A: Initial Standards and Requirements

Mike Duoba, Richard “Barney” Carlson, Ted Bohn, Daniel Bocci, Steve Gurski

Argonne National LaboratoryAdvanced Powertrain Research Facility

Vehicle Technologies Program

ver.2

2

Background SAE J1711

Original J1711First Approved in 1999Included PHEV testing, but never validated with PHEV hardware

Consensus Changes to Original J1711 to dateDo not combine fuel and electricity into a composite MPG Result– Report both MPG and AC Wh/mi (from plug)

Baseline charging assumption: 1 charge per day– Missed charge = Opportunity charging

Retain “Utility Factor” method of combining depleting with sustainingEmissions certification may not be the same procedure as fuel economy determination

3

Today’s Test Procedure For HybridsFTP and HWY

U U H H

U = UDDS CycleH = Highway Fuel Economy Test Cycle

10min rest, key off

15s rest, key stays on

Max 3h rest

prep test“cold-start”test

“hot-start”test

12-36h restU

prep

Requirement: Beginning SOC = Ending SOCWithin a battery energy tolerance of1% of cycle fuel energy

Weighted Urban Results = 0.43(cold-start) + 0.57(hot-start)

Step 1: Prep Step 2: Urban Test Step 3: Highway Test

4

Components of a PHEV Test

1. Full Charge Test (FCT) - Start fully charged, repeat cycle until car behaves like a charge-sustaining hybrid

2. Charge-Sustaining Test - Run test same as current charge-sustaining hybrids (in sustaining mode)

Challenges:1. Limitations of test cell hardware / software: 2. Vehicle initial conditions conflict with conventional vehicle procedures3. Compatibility with existing test procedures, conditions, and calculations

“Full Charge Test”(FCT)

Charge-Sustaining Test

(Full Charge)

Cycle 1 Cycle 2 Cycle 3 Cycle 4

until charge-sustaining

Cycle n..

5

J1711 Test Procedure Approach

Start

Default Test Method

Procedure(limited number of options)

Calculations(many viable options)

Option #1 Option #2

Option #3

Facility-Limited Method

Option #1 Option #2

Option #3

6

PHEV FCT Procedure for FTP

U U

Full

U U U U

10m

in

10m

in

10m

in

20To

30min

char

ge

U U U12h to

36h

Prep

?

U U

10m

in

U U U U U U U U

Full

10m

in

10m

in

10m

in

10m

in

10m

in

10m

in

10m

in

Best interpretation of FCT, but may not be possible for many test facilities

If above option is not possible, run this test

Test facility limitations require two test sequence choices.

U – Urban Dynamometer Drive Cycle (UDDS)

For Blended or AER Capable Vehicle

Day Before Test

20To

30min

20To

30min

7

PHEV Highway Cycle FCT Procedure

H H

char

ge

H H H12h to

36h

Prep

?

Full

H H H H H HH H

Full

H H H HFall-Back Option (test cell limited)

Prefer to run as many tests in a row as possible

Day Before Test

Remember the Conventional HWY Test

20to

30 min

20To

30 min

20To

30 min

Again, facility limitations require two options.

H – Highway Cycle

H H

15s rest, key stays on

prep test

8

Emissions Testing

J1711 to include emissions– emissions calculations same as fuel consumption– purposes of inventory predictions or other needs

For emissions certification Up to EPA procedures, not in scope of J1711 – worst case emissions, may be Depleting or Sustaining

test results

– OEMs demonstrate worst case

9

“Utility Factor”Utility Factor is used to Calculate aWeighted Fuel Consumption that Corresponds to Distribution of National Daily Miles Driven

10

SAE J2841Technical Information Report

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 10 20 30 40 50 60 70 80 90 100

Distance [miles]

Util

ity F

acto

r [%

]

“Definition of the Utility Factor for Plug-In Hybrid Electric Vehicles Using US DOT National Household Travel Survey Data”

63% of drivers have charge depletion capable distance of 40 miles

11

Testing PHEVs in the Advanced Powertrain Research Facilityat Argonne National Laboratory

12

ANL PHEV TestingTo Aid In J1711 Development

Prius Conversions1. Hymotion (Kokam) Prius (highly instrumented)2. HybridsPlus Prius (highly instrumented)3. Hymotion (A123 ver.1) Prius (AVTA)4. EnergyCS Prius ver.1 and ver.2 (AVTA)5. Hymotion (A123 ver.2) Prius (owned by A123)Escape Conversions6. Electrovaya Escape (AVTA / NYSERDA)7. Hymotion Escape (AVTA / NYSERDA)8. HybridsPlus Escape (AVTA / NYSERDA)Aug08OEM9. Renault Kangoo– OEM PHEV Mule (NDA-protected)– Extensive instrumentation/testing of OEM– More OEM PHEVs – Fall 2008

1 2

43

6

9

5

7

13

Example PHEV Test Results

Hymotion Escape

Supplemental battery– 8kWh rated– 6.2 kWh usable (from testing)– A123 cells– DC/DC converter supplements

stock NiMH battery

Electrovaya Escape

Supplemental battery– 12 kWh rated– 5 kWh usable (from testing)– Electrovaya cells– Series Pass Regulator

supplements stock NiMH battery

14

Hymotion Escape and Electrovaya Escapehave Different Rates of Depletion

Hymotion EscapeMPG (during CD) = 56AC Wh/mi (during CD) = 233(Constant Rate of Depletion)6.2 DCkWh usedPetroleum Displacement = 46%Actual Depleting Range = 35mi

Electrovaya EscapeMPG (during CD) = 43AC Wh/mi (during CD) = 183(Decreasing Rate of Depletion)5 DCkWh usedPetroleum Displacement= 34%Actual Depleting Range = 53 mi

15

Energy Management - Depletion Rate: A Tradeoff Of Fuel And Electricity

Charge Sustaining (stock Escape)

Electrovaya Escape

Hymotion Escape

Any well-designed control strategy will roughly fall on line

Faster depletion Less efficient operation

More efficient

Theoretical EV Wh/mi consumption

16

Entire Full Charge Test (FCT)Hymotion Escape

Cold-Start

Charge-DepletingTransitional Cycle

Charge Sustaining

Charge-balance window

Nearly ConstantDepletion Rate

17

Entire Full Charge Test (FCT)Electrovaya Escape

Cold-Start

Charge-Depleting

Charge Sustaining

Charge-balance window

DecreasingDepletion Rate

18

Let’s Explore PHEV MPG RatingsWith Utility Factors

UF weighting makes it advantageous to deplete as quickly as possible

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 10 20 30 40 50 60 70 80 90 100

PHEV Electric Range (Miles)

Max

% V

MT

on E

lect

rici

ty

Hymotion EscapeMPG (during CD) = 56.3AC Wh/mi (CD) = 233Depleting Range = 35miUF = 0.59

Bulk MethodUF-Weighted

MPG and Whr/mi= 44.1 MPG= 142 AC Whr/mi

Electrovaya EscapeMPG (during CD) = 42.7AC Wh/mi (CD) = 183Depleting Range = 53 miUF = 0.72

Bulk MethodUF-Weighted

MPG and Whr/mi= 39.4 MPG= 137 AC Whr/mi

1/ MPGUF = UF * Σ (1/MPGCD ) + (1-UF) * 1/MPGCS

Charge-depleting Charge-sustainingUF equation

19

Entire Full Charge Test (FCT)Hymotion Escape

Bulk Method UF WeightedFuel Consumption and Electrical Energy Consumption

Charge-balance window

20

Entire Full Charge Test (FCT)Electrovaya Escape

Charge-balance window

Bulk Method UF WeightedFuel Consumption and Electrical Energy Consumption

21

Piece-Wise Utility Factor Calculation

Piece-Wise Calculation applies a UF to each cycleThe minimum resolution is one cycle– Transition cycle is consider to be

part of the depletion operationThis method is gaining acceptance and may prevail as the preferred method

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 10 20 30 40 50 60 70 80 90 100

PHEV Electric Range (Miles)

Max

% V

MT

on E

lect

rici

ty

SOC

T1 T2 T3 T4 T5 T6 T7 T8

ZEV CDH CS

CD Cycles CS CyclesTests:

ΣMPG =

1

UFi (1/MPGCD)i + (1- Σ UFi )(1/ MPGCS)i=1

maxCD

i=1

maxCD

ΣUFi (AC Wh/miCD)i + (1- Σ UFi )(AC Wh/miCS)i=1

i=1

maxCD

AC Wh/mi =

UDDSDistance

[mi]Cummulative

UFCycle

UFCycle #1 7.5 0.1770 0.1770Cycle #2 15.0 0.3236 0.1466Cycle #3 22.4 0.4404 0.1167Cycle #4 29.9 0.5330 0.0927Cycle #5 37.4 0.6059 0.0729

22

Compare PHEV MPG RatingsWith the Two UF Calculations

Hymotion EscapeMPG (during CD) = 56.3AC Wh/mi (CD) = 233Depleting Range = 35mi

Bulk Method UF-Weighted= 44.1 MPG= 142 AC Whr/mi

Piece-Wise UF-Weighted= 44.1 MPG= 145 AC Whr/mi

Electrovaya EscapeMPG (during CD) = 42.7AC Wh/mi (CD) = 183Depleting Range = 53 mi

Bulk Method UF-Weighted= 39.4 MPG= 137 AC Whr/mi

Piece-Wise UF-Weighted= 39.7 MPG= 149 AC Whr/mi

23

Currently Addressing Final Challenges

Actual Charge-Depleting Range - Rcda"Electric Range Fraction” Equations

– SAE: ERF = 1- (FCcd / FCcs), FC=fuel consumption (units=?)– CARB: ERF = (Mass CO2cs - Mass CO2cd) / Mass CO2cs, (units = grams)

"Full Charge Test” (charge depleting) emissions compliance– Ywtd, g/mi = 0.43* Ycs/Dcs + 0.57* Sum of Yhs/Dhs results

Appropriate form of Voltage data for Net Energy Change calculation (NEC)HWY Cold-Start Correction Factor1% of Fuel Energy Window for charge sustaining acceptance criterion. AC Charging Sensitivity StudiesSensitivity to Soak Time Between Tests in FCT

24

We would like to gratefully acknowledge the sponsorship of Pat Davis, Acting Program Manager and Lee Slezak, Manager, Advanced Vehicle Systems Simulation & Evaluation Team, Office of Vehicle Technologies Program, U.S, Department of Energy.

Thank You

Vehicle Technologies Program

25

Backup Slides

26

Downloadable Dynamometer Database “D3”A Website To Download APRF Test Data

Easy search functionsBasic operational dataComprehensive data available upon requestMore features, reports uploaded in futurePHEV’s and HEV’s

https://webapps.anl.gov/vehicle_data

27

Utility Factor (UF) – Explanation

Daily driving distances determine ratio of depleting to total milesUS DOT National Highway Transportation Survey, 2001

Depleting range= 40mi

80% depleting, 20% sustaining

67% depleting, 33% sustaining

50% depleting, 50% sustaining

50

60

80

40

30

100% depleting, 0% sustaining

1 2 3 4 5

100% depleting, 0% sustaining

Vehicle:

distance driven on sample day

= sustaining

= depleting

UF(40) = ----------------------30+40+40+40+40

30+40+50+60+80

Depleting miles

Total miles

( )

∑

∑

∈

∈=

Rdk

Rdk

k

k

d

DdDUF

,min)(

28

SAE J1711

J1711

29

How Many Depleting Miles Experienced by All is the Utility Factor

If vehicle has 40mi depleting range, 63% of all miles drivenare in depleting mode

2001 NHTS Survey Data• 84,916 vehicles• 366,083 trips• 3,297,712 miles

Area under line is UF fraction

40mi

30

Defining a Plug-In HEV

EV Mode

SOC

Sustain Mode

Historically, PHEVs were defined as EV capable until battery depleted, then conventional HEV operation.“PHEV20” – 20mi EV range“PHEV60” – 60mi EV range x

miles EV range

SOC

Depleting Mode

SustainMode

Blended PHEVs do not require a “full performance” electric drive system. Engine operation needed during test cycle. But can deplete and displace a significant amount of fuel use.

= Engine-on

(start of day)

(start of day)

xmiles CD

range

“Charge-Sustaining”

“Charge-Depleting”

“Charge-Sustaining”

“Charge-Depleting”

31

Summary of “Electrified Vehicles”Vehicle Type Electric

PowerElectric Storage

Grid Connected

Electric Driving

Mild HEV Low Low No No

Full HEV Med Low No Very limited

ConversionPHEV

Med Med Yes Limited

AER- Capable

PHEVMed+ Med Yes UDDS

cycle

E-REVPHEV

High High Yes FullPerformance

BEV High High Yes Full Performance

Civic HEV

Escape HEVPrius HEV

Adapted from GM paper: “The Electrification of the Automobile: From Conventional Hybrid, to Plug-in Hybrids, to Extended-Range Electric Vehicles,” SAE 2008-01-0458

Toyota PHEV

GM Volt

RAV-4 EVEV1

VUE HEV

Hymotion Prius

AER = All Electric Range

32

E-REV

“Urban-Capable”

Blended

04 Prius Max Acceleration

PHEV– Differentiated by Electric Power

Whe

el k

WW

heel

kW

Both AER-Capable

33

Future of J1711

CARB PHEV Test Procedures and J1711 are linkedCARB staff must present final rule in October to BoardCARB will finish procedures this monthAs such, J1711 will also finish this summerJ1711 Committee now addressing final 8 testing issuesData from OEMs will help in this last stepEPA Label Fuel Economy still a difficult task – not in scope of J1711