Cummins Hybrid yCertification White

P O iPaper Overview

Cummins Hybrid Certification White Paperte ape

Evaluation and certification of hybrids presents unique h llchallenges– Regulatory development efforts in US, EU, and China– One prominent proposal is HILS

Cummins hybrid white paper proposes concept for h b id tifi tihybrid certification– Proposal was developed in response to EPA’s CO2 regulation

development, but may be applicable to EU and China– Hybrid concept builds on HD CO2 regulatory framework

described in Cummins CO2 white paper

2 2

Overview: Hybrid Certification Paper Key PointsPointsCritical Questions:

– What is certified?– What is certified?– How much will be simulated?

Main points of Cummins hybrid white paper– Certify Engine and Hybrid Components as a Set (called

a Powerpack)– Certify the Powerpack for both CO2 and Criteria– Utilize the dyno-based engine test cycle* to certify theUtilize the dyno based engine test cycle to certify the

Powerpack

* Some modifications are required to appropriately account for the dditi l h b id t

3 3

additional hybrid components

Cummins Guiding Principles for Regulation: Conventional & Hybridg y Simplicity: Find the right balance between real world fidelity and regulatory

complexity. Speed: Re-use existing vehicle, engine and component regulations and

protocols. Incentives: Utilize an incentive program to bring CO2 reduction technologies

to the market earlier.T h l U l i d li CO2 d i b d i i Technology: Use regulations to deliver CO2 reductions by driving technology into the vehicle, engine and critical sub-systems. Fairness: Avoid unintended consequences and maintain a level playing

fieldfield. Compliance: Provide for verifiable procedures and results. Feasibility: Ensure the implementation of best available technology with

current lead time and stability requirements.current lead time and stability requirements. Flexibility: Employ flexibility mechanisms in the current emissions program

such as averaging, banking and trading. Phase-In: Provide for a progressive approach to scope and stringency of

4 4

p g pp p g ystandards.

Vocational Market

• Vocational market has a wide range of applications that could b it bl f h b idi tibe suitable for hybridization

• A vehicle based certification program could lead toprogram could lead to significant proliferation of certifications

• Small volumes for many applications could make individual vehicle certifications impractical

5 5

Hybrids are “Active” Part of the System

FuelsReduced carbon intensityBio Diesel, CNG, LNG

Power Supply“Active”

Bio Diesel, CNG, LNG

EnginesEfficiency improvementsReduced Carbon FuelsH b idH b id

VehiclesTransmissions / Axles / TiresA d i

HybridsHybrids / Waste Heat Recovery Power Demand“Passive”

AerodynamicsTractor & Trailer - Smartway

Fleets / OperatorsIncentives for low GHG vehicles

Highways / InfrastructureHighway Construction / Congestion

Incentives for low GHG vehiclesLogistics, Driver training & aids

6 6

g y gSpeed limitsGVW

Key CO2 Reduction Technologies are Engine Dependent and Interdependentg p p

7 7

Hybrids have significant interaction with the engine and significant interaction with other engine-based CO2 reduction technologies

Hybrid CO2 Reduction Results from the Fact that the Engines in Hybrid Systems Operate

Differently than Conventional Diesel Engines

Conventional vs HybridHybrid Decouples Engine Power from Vehicle Power Reduced Cycle Work (from

Regenerative Braking)

St t / St O ti600

800

1000

(Nm

)

BaseHybrid

Start / Stop Operation

Increased Average Load

EngineStart/Stop

200

400

600

Eng

ine

Torq

ue

Opportunity to Manage Transient Load & Exhaust Temperatures640 645 650 655 660 665 670

0

time

The amount of CO2 is dependent upon the engine and upon the interaction of key components within the Hybrid Power Pack:

8 8

Hybrid Should be certified for both criteria and CO2 together.

Decoupling Engine Power from Vehicle Power Could Have Unintended Consequences Existing engine dyno cert assumes engine power matches vehicle

power. If hybrid decouples engine power from vehicle power, FTP cycle no

l i t f h b id i tifi tilonger appropriate for hybrid engine certification. Mis-match between certification & real world operation could lead to

higher criteria emissions, and less than optimal CO2 emissions reductionreduction.

mis

sion

s Existing Cert:Potential In-Use

C it i Li it

Existing Cert:Cert Result

Target Achieved with

Appropriate CertCrit

eria

Em Criteria Limit

9 9

Appropriate Cert

CO2 Emissions

C

Hybrid with Engine Certified Over Traditional FTP may Produce Higher Criteria EmissionsFTP may Produce Higher Criteria Emissions

DOE / NREL chassis test evaluation of hybrid P&D vehicle CO2 & criteria emissions

Eaton hybrid system

P100 van P100 van

CILCC Cycle

In this case hybridization resulted in lower PM emissions,

10 10

In this case hybridization resulted in lower PM emissions,but higher NOx emissions.

Hybrid should be Certified Jointly for Both Criteria and CO2 EmissionsCriteria and CO2 Emissions

on

)

Ensure real world critieria emissions equivalent to conventional

onsu

mpt

iopr

ovem

ent

Maximize opportunities for CO2 reduction

Allow for future technology development

~ 25% (CurrentSystems)

Fuel

Co

(% Im

p

gy(engine electrification & integration with hybrid system)

Alignment of CO2 & criteria certification is consistent with CO2 regulatory concepts for conventional powertrains.

Alignment of CO2 & criteria cert can enable 5-10% additional CO2 reduction that is not available today

11 11

reduction, that is not available todayGreater optimization can also reduce engine hardware cost and

improve reliability of system

Hybrid Certification Should Build on Existing Engine Certification

Existing FTP transient engine dyno test accurately describes hi l i t f id f ti lvehicle power requirements for a wide range of vocational

applications Significant industry experience with FTP procedures and protocols

Conventional Certification

Dyno• Use the normalized engine form of the cycle• Engine torque curve defines actual speed and torque for

Emissions

Work

EngineFuel

actual speed and torque for certification test• Emissions: g/hp-hr• Integrate only positive work (motoring work not included)

Work

Motor

12 12

Hybrid Certification of Pre-Transmission Hybrids Pre-transmission powerpack could utilize existing procedures and

protocols with minor modifications For many hybrid systems this approach would allow hardware

evaluation of engine, motor, battery, etc. One certification, many applications

Uses same simplifying assumptions as conventional certifications

Allow comparative performance evaluation with conventional

DEmissionsHybrid Certification:

Pre-Transmission Hybrid These are actual t ( t

p pengine

Motor /EngineFuel

Dyno

Work

Pre-Transmission Hybrid components (not simulated)• Use the normalized engine form

of the cycle(s)• Pre-transmission system torque

curve defines actual speed andGenEngine

Clutch

PowerMotor

(Regen)

curve defines actual speed and torque for certification test

• Emissions: g/hp-hr• Allow capture of energy during

“motoring” portions of FTPCount only positive work (as with

13 13

Battery PowerElec.

(Regen)• Count only positive work (as with conventional engines)

Post-Transmission Power Pack Certification Pre-transmission powerpack certification not viable for all hybrid p p y

architectures Post-transmission powerpack certification would work for series and other

transmission integrated hybrid systems

Hybrid Certification: Post-Transmission Option

Cycle based on FTP would allow comparative evaluation with conventional and pre-trans hybrid

U li d t

DEmissions

Hybrid Certification: Post-Transmission Option

These are actual t ( t

• Use normalized post-transmission test cycle(s)

• Post-transmission system torque curve

Motor /EngineFuel

Dyno

Work

components (not simulated)

Trans

y qdefines actual speed and torque for certification test

• Emissions: g/hp-hr• Allow capture of

GenEngine

Clutch

PowerMotor

(Regen)

Trans• Allow capture of energy during braking portions of cycle

• Count only positive

14 14

Battery PowerElec.

(Regen)work (as with conventional engines)

Powerpack and HILS

HILS very attractive, but presents some challenges– Development of models for some hybrid components (batteries)

Verification of compliance– Verification of compliance– Test cycle selection, standards for new cycles, and comparison with

conventional certification results

Powerpack is a form of HILS– Aero, rolling resistance, wheels, differential (+transmission in pre-

trans option) all simulated.

Advantages of powerpack concept Advantages of powerpack concept– Certifying powerpack would reduce proliferation– Inclusion of criteria emissions and CO2 allows maximum optimization

Inclusion of hybrid HW enables fast implementation

15 15

– Inclusion of hybrid HW enables fast implementation

Summary

Cummins hybrid white paper– Certify powerpack– Test all hybrid components – Certify for both criteria emissions and CO2– Build on existing experience with engine dyno based g p g y

certification

Questions:– Would powerpack approach be applicable to EU or China?– Is powerpack approach compatible with HILS?– Is powerpack approach compatible with HILS?

16 16

Appendix: Limiting of regen brakingLimiting of regen braking

17 17

Capture of Regen Energy could be Approximated by Capturing Dyno Energy Approximated by Capturing Dyno Energy during Motoring Portions of FTP

FTP torque based on system torque (blue)

600

800

1000

Regen torque based on capability of 60kW motor/gen during motoring

0

200

400

Torq

ue (N

m)

during motoring portions of FTP

-600

-400

-200

0 200 400 600 800 1000 1200

Time (sec)

System Torque Regen Torque

18 18

This strategy would allow capture of energy in a battery,which is a key feature of hybrids.

Definition of a “Vehicle FTP” Will Allow Hybrid Certification of All Hybrid SystemsHybrid Certification of All Hybrid Systems

FTP defines speed andFTP for 260 hp 6.7L ISB

FTP defines speed and torque requirements for engine

1500200025003000

(RPM

)

3500

4500

e (N

m)

Engine speed and torque can be used to determine power going to wheels to accelerate0

50010001500

ngin

e Sp

eed

500

1500

2500

ngin

e To

rque

to wheels to accelerate vehicle

Engine power combined with engine speed can

-1000-500

0 200 400 600 800 1000 1200

Time (seconds)

En

-500

500 En

with engine speed can define vehicle speed

Time (seconds)

Engine Speed Engine Torque

19 19

Engine speed and torque can be used to define vehicle speed.

Definition of a Post Transmission FTP Will Allow Hybrid Certification of All Hybrid SystemsHybrid Certification of All Hybrid SystemsFTP defines speed and torque requirements for engineAcceleration: If engine torque positive, engine speed and torque can be

used to determine power going to wheels to accelerate vehicleused to determine power going to wheels to accelerate vehicle

PMgfVAreaC

onAcceleratiMassForceForce

accessory

VehLoadEngine

2***1

*

Deceleration: Engine torque negativeM

VMgfVAreaC

MVP

Accel

yrollingaird

Eng

***

2

g q g– If engine speed ~ constant assume coasting and calculate deceleration

based on motoring engine torque.– If engine speed decelerates quickly, assume braking.

• At > 15 mph calculate vehicle deceleration based on engineAt > 15 mph, calculate vehicle deceleration based on engine deceleration

• At < 15 mph, decelerate vehicle at 1.5 m/s2

20 20

Engine speed and torque can be used to define vehicle speed.

Definition of a Post Transmission FTP Will Allow Hybrid Certification of All Hybrid Systems

70

80Vehicle FTP Cycle

ISC8.3L, 24947.5kg Beverage TractorISB6.7L, 11793.4kg P&DISB4.5L, 12000kg P&DISB3.8L, 12000kg P&D

“Average” cycle could be defined based on

l l d

50

60

h)

g

calculated vehicle speed for a range of engines &

hi l

30

40

Veh

icle

Spe

ed(m

ph vehicles.

Vehicle speed could also be

20

30 could also be used to calculate maximum regen energy available to ensure

0 200 400 600 800 1000 12000

10

Time(sec)

to ensure powerpack energy capture is realistic.

21 21

Vehicle speed vs. time will be consistent with FTP in terms of engine power requirements.

Strategies to Ensure Representative Regen Energy Capture

1. Allow capture up to capability of system Economics will limit system size, which will limit energy

capturedcaptured

2. Place upper limit on energy captured over cycle based on available brake energy in real world cycles Evaluate range of applications and duty cycles to determine

appropriate level for brake energy

3. Calculate second-by-second available regen torque3. Calculate second by second available regen torque based on FTP

22 22

Allow capture up to capability of system Allo ing energ capt re d ring motoring portions of Allowing energy capture during motoring portions of

FTP results in reasonable matches with real world regen for many systems.

45%

50% Simulation result: Bus w/100 kW hybridManhattan cycle

30%

35%

40%

45%

as %

of

ve W

ork

15%

20%

25%

Rege

n En

ergy

ys

tem

Pos

itiv

Si l ti lt B d li ith

0%

5%

10%

R S Simulation result: Bev delivery withParallel hybrid (50kW) over HD UDDS cycle

23 23

0% 10% 20% 30% 40% 50% 60% 70%

Generator Power as % of System Positive Power

Allow capture up to capability of system

Example of system, engine, and regen torque curves

800

1200

1600

(Nm

)

System torque curve defines positiveFTP torque & speed requirements

-400

0

400

Torq

ue (

Motor & battery capability define-800

800 1300 1800 2300 2800

Speed (RPM)

System Torque Engine Torque Regen Capability

Motor & battery capability defineregen torque curve

During motoring portions of FTP,regen torque curve defines torque

24 24

System Torque Engine Torque Regen Capability

Place upper limit on energy captured over cycle based on available brake energy in real world cycles

45%

50% Bus: Max availableM h tt

30%

35%

40%

45%

as %

of

e W

ork

regen over Manhattan

15%

20%

25%

30%

gen

Ener

gy a

stem

Pos

itive P&D: Max available

regen over HTUF P&D

0%

5%

10%

15%

Re Sys

0%0% 10% 20% 30% 40% 50% 60% 70%

Generator Power as % of System Positive Power

25 25

Strategies to Ensure Representative Regen Energy Capture:gy pCalculation of Available Regen Energy

FTP defines speed & torque – Power– Good match between FTP & real world vehicle power p

requirements

By making an assumption on a typical vehicle for a given torque curve it is possible to calculate a second bytorque curve – it is possible to calculate a second-by-second regen energy limit.

26 26

Methodology

1000

1500

2000

2500

Spe

ed (R

PM

)

1000

1500

2000

2500

Spe

ed (R

PM

)

Modified FTP Engine SpeedOriginal FTP Engine Speed Example:

- Engine FTP Cycle to Vehicle FTP Cycle

0 200 400 600 800 1000 12000

500

Time (sec)

800

1000

0 200 400 600 800 1000 12000

500

Time (sec)

800

1000

- ISC 8.3L, 330hp Engine

- 55000 lbs vehicle

- Assumptions on frontal area, drag coefficient, rolling resistance, first gear

0 200 400 600 800 1000 1200-200

0

200

400

600

Time (sec)

Torq

ue (f

t-lb)

0 200 400 600 800 1000 1200-200

0

200

400

600

Time (sec)

Torq

ue (f

t-lb)

FTP defines speed and torque requirements for engine

coefficient, rolling resistance, first gear & final drive ratio

- Assumption on coasting vs. braking regimes

p q q gAcceleration: If engine torque positive, engine speed and torque can be used to

determine power going to wheels to accelerate vehicle

onAcceleratiMassForceForce *

MV

PMgfVAreaC

MVP

Accel

onAcceleratiMassForceForce

accessoryrollingaird

Eng

VehLoadEngine

2***21

*

27 27

Deceleration: Engine torque negative– If engine speed ~ constant assume coasting and calculate deceleration based on motoring engine

torque.– If engine speed decelerates quickly, assume braking at 1.5 m/s2

MethodologyIdle Speed modified to Engine OFF,

vehicle speed=0mph

Acceleration: Use formula to calculate

vehicle speed

Deceleration: Braking to 0

speed at 1.5m/s2

1000

1500

2000

2500

Spe

ed (R

PM

)

1000

1500

2000

2500

Spe

ed (R

PM

)

Modified FTP Engine SpeedOriginal FTP Engine Speed

p p

50

60

70g y

0 200 400 600 800 1000 12000

500

Time (sec)

800

1000

0 200 400 600 800 1000 12000

500

Time (sec)

800

1000

20

30

40

50

Veh

icle

Spe

ed (m

ph)

Coasting: Use formula to calculate

coasting speed

0 200 400 600 800 1000 1200-200

0

200

400

600

Time (sec)

Torq

ue (f

t-lb)

0 200 400 600 800 1000 1200-200

0

200

400

600

Time (sec)

Torq

ue (f

t-lb)

FTP defines speed and torque requirements for engine0 200 400 600 800 1000 1200

0

10

Time (sec)

FTP defines speed and torque requirements for engineAcceleration: If engine torque positive, engine speed and torque can be

used to determine power going to wheels to accelerate vehicle

onAcceleratiMassForceForce *

MV

PMgfVAreaC

MVP

Accel

onAcceleratiMassForceForce

accessoryrollingaird

Eng

VehLoadEngine

2***21

*

28 28

Deceleration: Engine torque negative– If engine speed ~ constant assume coasting and calculate deceleration based on

motoring engine torque.– If engine speed decelerates quickly, assume braking at 1.5 m/s2

Proposed Vehicle FTP Cycle70

Vehicle FTP Cycle

ISC8 3L 330hp 55000lbs70

Averaged Vehicle FTP Cycle

40

50

60

ed (m

ph)

ISC8.3L,330hp,55000lbsISB6.7L,280hp,46500lbsISB4.5L,182hp,30250lbsISF3.8L,167hp,27750lbs

40

50

60

ed (m

ph)

10

20

30

Veh

icle

Spe

e

10

20

30

Veh

icle

Spe

eAveraged

0 200 400 600 800 1000 12000

10

Time (sec)

0 200 400 600 800 1000 1200

0

10

Time (sec)

B k E % f +

Engine for FTP Vehicle FTP3.8L 39.40

Brake Energy as % of +ve Traction Energy

4.5L 39.726.7L 44.938.3L 45.92Average 42.49

Matches with HD UDDS cycle potential of about 40 to 45% (based on application)

29 29

Conventional Engine FTP Cycle speed and torque can be used to define vehicle speed for Vehicle FTP Cycle

MethodologyIdle Speed modified to Engine OFF,

vehicle speed=0mph

Acceleration: Use formula to calculate

vehicle speed

Deceleration: Braking to 0

speed at 3mph/s

1000

1500

2000

2500

Spe

ed (R

PM

)

1000

1500

2000

2500

Spe

ed (R

PM

)

Modified FTP Engine SpeedOriginal FTP Engine Speed

p p

0

500Vehicle FTP Cycle Traction & Braking Power

0 200 400 600 800 1000 12000

500

Time (sec)

800

1000

0 200 400 600 800 1000 12000

500

Time (sec)

800

1000

Coasting: Use formula to calculate

coasting speed -1000

-500

Pow

er (k

W)

0 200 400 600 800 1000 1200-200

0

200

400

600

Time (sec)

Torq

ue (f

t-lb)

0 200 400 600 800 1000 1200-200

0

200

400

600

Time (sec)

Torq

ue (f

t-lb)

FTP defines speed and torque requirements for engine0 200 400 600 800 1000 1200

-2000

-1500

Time(sec)

FTP defines speed and torque requirements for engineAcceleration: If engine torque positive, engine speed and torque can be used to

determine power going to wheels to accelerate vehicle

onAcceleratiMassForceForce *

MV

PMgfVAreaC

MVP

Accel

onAcceleratiMassForceForce

accessoryrollingaird

Eng

VehLoadEngine

2***21

*

0

0

)**(

)**(

Accelwhen

Accelwhen

VAccelMPowerDriving

VAccelMPowerBraking

30 30

Deceleration: Engine torque negative– If engine speed ~ constant assume coasting and calculate deceleration based on motoring engine

torque.– If engine speed decelerates quickly, assume braking at 1.5 m/s2

Available Regen Torque

500Vehicle FTP Cycle Traction & Braking Power

1000Vehicle FTP Cycle Braking Torque as % of Max. Engine Torque

00

-500

0

W) 600

700

800

900

. Eng

ine

Torq

ue (%

)

60

70

80

90

-1500

-1000Pow

er (k

W

200

300

400

500

ing

Torq

ue a

s %

of M

ax.

Normalized

20

30

40

50

0 200 400 600 800 1000 1200-2000

Time(sec)0 200 400 600 800 1000 1200

0

100

Time(sec)

Bra

ki

0

10

31 31Conventional Engine FTP Cycle speed and torque can be used to define a brake

limit for the Hybrid FTP Cycle