PHEV Energy St

Drive Cyc

7th Advanced Automotive B

Lo

Tony Markel and A

(Tony_

National Renewable 

FreedomCAR and Veh

Office of Energy Efficien

NREL/PR-540-42026
• Background - Summary of Previous • Key Messages of this Study • Real-World Drive Cycles• PHEV Recharge Options• Operational Impacts on

— Pulse Power — State of Charge

• Conclusions
Key Messages o

• Petroleum Consumption

— The fuel displacement benefits of PH

influenced by the frequency of rechar

• Pulse Power Attributes

— PHEVs are likely to encounter long p

events during real-world duty cycles

— PHEV experiences similar power leve

longer pulses than HEV

• State of Charge

— Time at specified state of charge vari

with platform and recharge scenario
Standard and Real-World D

• Standard drive cycles used for certification/compar

— UDDS, HWFET, US06, SC03— Japan-1015— NEDC

• These drive cycles are meant to be representative 

— Fuel economy labeling under revision and likely to 

broader set of cycles to address differences betwconsumer experience

• Real-world driving patterns provides insight on in-u

acceleration characteristics

— PHEV recharge scenarios and grid impacts can b

with time of day information

Drive cycle Vehicle Simulations

Fuel Econom

Fuel Cost

Power Nee

Energy Nee

Vehicle 

attributes
• Key insights

— Speed and acceleration distributions— Time of day usage for recharge analysis— Combined impact of speed and grade— Location and duration of stops for recharge o

Real-World Drive Cycle 

• Driving/travel survey is ongoing in many cities (e• Augmenting these surveys with GPS information 

vehicles provide details needed for simulation

• 1Hz data collected 

— Time of day— Speed— Altitude— Latitude— Longitude
Sample Real World 

0

5 10 15 20 

0

20406080

Speed (mph)

Time (hr)

0

5 10 15 20 25 30 35 4

0

20406080

Speed (mph)

Distance (mi)
PHEVs Reduce Fuel Consum

On Real-World 

Vehicle in-use activity pattern and simulated fuel consumption

— In-use bars show morning, 

midday and evening usage peaks; at most 12% of vehicles in use at once

— Cumulative fuel 

consumption lines consider entire fleet using specified architecture

Assumption• PHEVs b

charge u

• Gasoline 

$0.09/kW(purchas

St. Louis Data Samp
Four Potential Daily Recharg

Immediate End of Travel Day

3 ways to control a single daily charge Multiple cha
Recharge Scenario Impacts on P

Consum

Oppo

Cha

(PHE

No Charg

(PHEV20)

Opportunity charge: connect PHEV charger to grid any time t

Base Case 

assumes one full 

charge per day
• Background - Summary of Previous • Key Messages of this Study • Real-World Drive Cycles• PHEV Recharge Options• Operational Impacts on

— Pulse Power — State of Charge

• Conclusions
Two Ways to Analyze Battery Po

• Power Pulse event

— Start - first non-zero— End – next non-zero

• Attributes

— Peak power and peak power duration— Energy equivalent average power an

• Provides detail on specific events• Moving window approach 

— Integrate power profile over a specifie

find net, positive only, and negative opowers

— Captures interaction between multipl
Characteristics of an Individual Puls

0

5 10 15 20 

0

204060

Speed (mph)

0

5 10 15 20 

0

0.5

1

SOC (--)

0

5 10 15 20 

-50

0

50

100

Power (kW)

Distance (mi)
0 5 

0

204060

Speed (mph)

0 5 

0

0.5

1

SOC (--)

0 5 

-50

0

50

100

Power (kW)

Characteristics of an Individual Puls
Expanding window captures 

event interactions

Moving Window Analysis of ESS 

Quantifies Interaction Between Ind

• • 
0 50 100 150 200 

-30-20-10

0

102030405060

Average Power Pulse Duration (s)

Maximum Average Power Pulse (kW)

Max. Moving Window PowerMin. Moving Window PowerAvg. Power of EventsPeak Power of Events

Detailed Pulse Power Analysis of Rea

Identifies Most Chal

SLpMin 

Curve higher than points

Highlights event interaction
HEV Conv.

Pulse Power Characteristic

Opera

UDDS CDE

Total Event Duration

Power

Time

Peak Pulse Power Duration

Ene

Pu

Charge depleting electric (CDE) is likely to have 

events and moderate long duration energy 
HEV Conv.

Pulse Power Characteristic

Opera

Vehicles designed as CDE on UDDS are l

as CDH on real-world duty cy

UDDS CDE

Total Event Duration

Power

Time

Peak Pulse Power Duration

Ene

Pu

Charge depleting electric (CDE) is likely to have 

events and moderate long duration energy 

Charge depleting hybrid (CDH) will have lower b

and slightly lower energy equiv. pulse powe

Low CDH
HEV Conv.

Pulse Power Characteristic

Opera

Vehicles designed as CDE on UDDS are l

as CDH on real-world duty cy

UDDS CDE

Total Event Duration

CDH

Power

Time

Peak Pulse Power Duration

Ene

Pu

Low CDH

Charge depleting electric (CDE) is likely to have 

events and moderate long duration energy 

Charge depleting hybrid (CDH) will have lower b

and slightly lower energy equiv. pulse powe

In CDH lower power case, the Peak and 

Pulse Powers may have similar leve
Pulse Power from Simulated P

on 227 Real-World 

0 20 40 60 80 100 120 140 160 180 

-30-20-10

0

102030405060

Pulse Power Duration (s)

Max. Energy Equiv. Pulse Power (kW)10th Percentile 50th Percentile 90th Percentile

• Components sized for AER on UDDS (CD

encounter long duration energy equiv. pow

Ma

spec

Typically specified

at 2S and 10S 

Midsize Car PHEV20 w/AER on UDDS
Pulse Power Analysis Methods Ca

to Both Simulation Results a

0 50 

-30-20-10

0

102030405060

A

Maximum Average Power Pulse (kW)

PHEV Research Vehicle Urban Driving Data
PHEV Time At SOC Impacted by Cha

0

102030405060708090

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 

State of Charge Zone

% of Day at State of Charge

Will differences in Time 

at SOC affect battery 

life?

Based on Simulation of 227 duty cycles 

from St. Louis
C

• Pulse Power Analysis Methods

— Moving window allows evaluation of interaction 

• Petroleum Consumption Relative to Convent

— PHEV20 with single daily charge saves about 5— PHEV20 without charging similar to HEV (~35%— PHEV20 with opportunity charge saves 75%

• Pulse Power Attributes

— Real-world pulse power events have longer dur

test cycles

— PHEV similar power levels but much longer pul— CDH peak power is lower but duration is longer — CDH energy equiv. power is slightly lower with 

• State of Charge

— No charge leads to long periods of battery at lo— Single charge leads to mixture of high and low — Multiple charges leads to more time at high SO
• Use battery models representative in bot

duration pulses

• Determine key aspects affecting battery l• Continue to use travel data to assess imp

technology, especially on batteries

— Charge-depleting electric and charge-deple

operating scenarios

— PHEV10 scenario— Affect of ambient conditions on fuel displac— Assess battery usage under V2G scenario— Emissions impacts of engine operation— Use travel data from five other municipalitie

• Collect on-road data with PHEV research 

vehicle using several battery options and compare with simulation results
Acknowl

• Programmatic Support of FreedomC

Vehicle Technologies Program of th

— Tien Duong, Vehicle Technologies 

— David Howell, Energy Storage Sys— Lee Slezak, Vehicle Systems 

• Technical Support from East West C

Governments (St. Louis, Missouri)

— Todd Barat