november 13, 2008 heavy duty hybrid truck 1 development of a hybrid electric heavy duty truck kemal...

November 13, 2008 Heavy Duty Hybrid Truck 1

DEVELOPMENT OF A HYBRID DEVELOPMENT OF A HYBRID ELECTRIC HEAVY DUTY TRUCKELECTRIC HEAVY DUTY TRUCK

Kemal ÇalışkanKemal ÇalışkanProf. Dr. Y. Samim ÜnlüsoyProf. Dr. Y. Samim Ünlüsoy

Varlık KılıçVarlık KılıçDr. Murat YıldırımDr. Murat Yıldırım

Middle East Technical Middle East Technical UniversityUniversity

FORD OTOSANFORD OTOSAN


HYBRID TRUCKSHYBRID TRUCKS

In recent years, heavy commercial In recent years, heavy commercial vehicles are equipped with engines of ever vehicles are equipped with engines of ever increasing power.increasing power.

As an alternative of replacing the engine As an alternative of replacing the engine with a larger one, vehicle performance can with a larger one, vehicle performance can also also be improved by hybridizationbe improved by hybridization..



Heavy commercial vehicles are driven for Heavy commercial vehicles are driven for very long distances during their very long distances during their operational lives and account for a operational lives and account for a significant portion of the overall fuel significant portion of the overall fuel consumption.consumption.

PPossible reduction of fuel consumption ossible reduction of fuel consumption and emissions for these vehicles by the and emissions for these vehicles by the application of hybrid electric propulsion application of hybrid electric propulsion systems systems willwill be significant be significant . .



As opposed to the common objective of As opposed to the common objective of reduced fuel consumption and emissions reduced fuel consumption and emissions by hybridization; this study presents an by hybridization; this study presents an application in which performance application in which performance improvement is the main objective, with improvement is the main objective, with the associated improvement in fuel the associated improvement in fuel consumption and emissions as a consumption and emissions as a secondary benefit.secondary benefit.



Some of the main truck manufacturer Some of the main truck manufacturer companies have already developed companies have already developed medium sized hybrid trucks and they medium sized hybrid trucks and they are working on the development of are working on the development of heavy duty hybrid trucks.heavy duty hybrid trucks.

November 13, 2008 6Heavy Duty Hybrid Truck

HYBRID TRUCKSHYBRID TRUCKSMACK

• Class 8• 2005 US AirForce Prototype• 80kW EM

DAF / EATON

• Class 8• 44kW EM• Release 2009• Li-Ion Battery System

VOLVO

• Class 8• Job#1 2009• 120kW EM• NiMH

PACCAR/AZURE

• Class 7• 2 prototypes• 7.2L diesel• 90kW EM• UCAP


OBJECTIVESOBJECTIVES Main objective :Main objective : tto obtain the performance of a o obtain the performance of a heavy truckheavy truck

equipped with a equipped with a

- - 12.5 liter diesel engine of 12.5 liter diesel engine of 500500 PSPS rated rated power, power,

from a hybrid configuration of a from a hybrid configuration of a

- - 9 liter diesel engine with 9 liter diesel engine with 400400 PSPS rated rated power and a suitably sized electric power and a suitably sized electric

motor.motor.

SSecondary econdary objectives :objectives :

Reduced fReduced fuel uel consumptionconsumption and emission and emissions.s.


TARGET VEHICLETARGET VEHICLE

4x2 Tractor4x2 Tractor

40 ton Loaded40 ton Loaded

9 liter 4009 liter 400 PSPS Diesel EngineDiesel Engine

16 Gear Manual 16 Gear Manual TransmissionTransmission


PRELIMINARY ANALYSISPRELIMINARY ANALYSIS

EExamine xamine and compare and compare the performance the performance of basic hybrid configurationsof basic hybrid configurations..

DetermineDetermine the basic specifications ofthe basic specifications of the electric motorthe electric motor and the battery and the battery forfor the the different different hybrid configurationshybrid configurations to to satisfy the performance objectives.satisfy the performance objectives.

DDetermine the etermine the performance and performance and fuel fuel consumption consumption forfor different different configurationsconfigurations using using standard truck standard truck driving cycles.driving cycles.



For the preliminary simulations of hybrid For the preliminary simulations of hybrid configurations, Nconfigurations, NREL’s publicly available REL’s publicly available vehicle simulation tool, ADVISOR software is vehicle simulation tool, ADVISOR software is used, after being used, after being correctedcorrected and and modifiedmodified for for heavy heavy ccommercial vehicle analysisommercial vehicle analysis::

- Converted to rear wheel drive.- Converted to rear wheel drive.- Trailer hinge loads are included.- Trailer hinge loads are included.- Different hybrid configurations.- Different hybrid configurations.- Some errors were discovered and - Some errors were discovered and

corrected.corrected.

CComponentomponent data we data were confined to those re confined to those available in the data files of Aavailable in the data files of ADVISOR.DVISOR.


Simulation studies indicated Simulation studies indicated that an that an EMEM which is capable which is capable of producing of at leastof producing of at least::

400 Nm 400 Nm torque @torque @ 1600 rpm 1600 rpm,,

and and 70-80 kW 70-80 kW power power in the in the speed range from 1000 to speed range from 1000 to 2200 rpm2200 rpm

must be specified.must be specified.

The The EMEM is to be a shaft is to be a shaft motor with a shaft torque motor with a shaft torque capacity of at least 2000 Nm.capacity of at least 2000 Nm.



It was It was foundfound that a battery group of that a battery group of : :

- - 90Ah capacity at 360V90Ah capacity at 360V

- o- operated within 20% stateperated within 20% state of of

charge (SOC) level (e.g. maxcharge (SOC) level (e.g. max

70% - min 50%) 70% - min 50%)

can feed the electric motor at full can feed the electric motor at full power for five minutes. power for five minutes.



Fuel consumptions of the conventional Fuel consumptions of the conventional and hybrid configurations on a number and hybrid configurations on a number of drive cycles showed that 10-50 % of drive cycles showed that 10-50 % reduction in fuel consumption, compared reduction in fuel consumption, compared to 12.5 liter, can be realized depending to 12.5 liter, can be realized depending on the cycle of interest. on the cycle of interest.

The highest reduction in fuel The highest reduction in fuel consumption is obtained in the cycles consumption is obtained in the cycles which represent low speed profile with which represent low speed profile with considerable idling periods.considerable idling periods.



SELECTION OF HYBRID SELECTION OF HYBRID COMPONENTSCOMPONENTS

The required electric motor specifications The required electric motor specifications are satisfied by a 100 kW rated power are satisfied by a 100 kW rated power (continuous) (continuous) EM EM ..

The required battery specifications The required battery specifications areare satisfied by the custom designed battery satisfied by the custom designed battery pack containing 200 unitspack containing 200 units ( (100100 Series 2Series 2 ParallelParallel)) of 45Ah Li-Ion of 45Ah Li-Ion ccellsells. The total . The total capacity capacity 32.432.4 kWhkWh and n and nomominal operatinginal operating vvoltageoltage is is 360V360V..


PossiblePossibleHybridHybridConfigurationsConfigurations


Selection of ConfigurationSelection of Configuration

OOperation of the hybrid vehicle should peration of the hybrid vehicle should be as similar to the conventional be as similar to the conventional vehiclevehicle as possible. as possible.

SSelection of a certain configuration election of a certain configuration may be dictated by the packaging may be dictated by the packaging requirements for the particular vehicle requirements for the particular vehicle to be hybridized.to be hybridized.

Minimum change in the original vehicle Minimum change in the original vehicle configuration is desired.configuration is desired.



In view of the above criteria, it is decided In view of the above criteria, it is decided to carry out detailed to carry out detailed acceleration, acceleration, gradeability and fuel consumption gradeability and fuel consumption simulations for the three simulations for the three candidate candidate hybrid hybrid configurationsconfigurations..

Parallel hybrid driveline with electric Parallel hybrid driveline with electric motor motor located: located:

- after clutch,- after clutch,

- before clutch, and- before clutch, and

- after transmission.- after transmission.



After the results of the simulation After the results of the simulation studies are obtained, the simulated studies are obtained, the simulated performance of each hybrid driveline performance of each hybrid driveline configuration is compared with those configuration is compared with those of:of:

- conventional with 9 lt, and- conventional with 9 lt, and

- conventional 12.5 lt engines.- conventional 12.5 lt engines.


ACCELERATION PERFORMANCEACCELERATION PERFORMANCE

Order of Order of MeritMerit

55

33

11

11

44


GRADEABILITY [%]GRADEABILITY [%]

Order of Order of MeritMerit

55

11

11

11

44


FUEL CONSUMPTION [lt/100km]FUEL CONSUMPTION [lt/100km]

NYGTC WUINTERUDDSFDV

Reference


Comparison of the Hybrid Comparison of the Hybrid ConfigurationsConfigurations


TheThe two choices, after-clutch and pre- two choices, after-clutch and pre-clutch, do not have any clear advantages clutch, do not have any clear advantages over each other with respect to over each other with respect to performanceperformance, fuel consumption, and , fuel consumption, and required driveline modifications.required driveline modifications.

Before clutch configuration lacks the Before clutch configuration lacks the ability of pure electric drive while the ability of pure electric drive while the after clutch configuration have problems after clutch configuration have problems with idle charging and using EM as the with idle charging and using EM as the starter.starter.



Selection of ConfigurationSelection of Configuration It is decided to employ the “Double Clutch It is decided to employ the “Double Clutch

Parallel Hybrid” configuration. This Parallel Hybrid” configuration. This configuration will include both the before configuration will include both the before clutch and after clutch configurations. clutch and after clutch configurations.

It will thus be possible to observe advantages It will thus be possible to observe advantages and disadvantages of both configurations by and disadvantages of both configurations by disabling one of the clutches at a time.disabling one of the clutches at a time.


PACKAGINGPACKAGING


CHASIS MODIFICATIONSCHASIS MODIFICATIONS

EngineEngine mounts and mounts and locations locations

Fuel tank position Fuel tank position and mountsand mounts

Li-Ion battery pack Li-Ion battery pack mountsmounts

Electric motor Electric motor housing and mountshousing and mounts

Propeller shaftPropeller shaft Rear splash shield Rear splash shield

bracketsbrackets

Brake Pedal SensorBrake Pedal Sensor Electric motor cooling Electric motor cooling

pump, radiator and pump, radiator and hoseshoses

Clutch control system Clutch control system pipes pipes

HV CablingHV Cabling Gear shifting cablesGear shifting cables Brake pipesBrake pipes

Fuel pipesFuel pipes


BRAKING SYTEMBRAKING SYTEM

To satisfy the lTo satisfy the legal requirementegal requirementss for for braking of commercial vehiclesbraking of commercial vehicles a a secondary secondary braking braking system is system is necessarynecessary..

The large and heavy retarder of the The large and heavy retarder of the vehicle is to be replaced with a vehicle is to be replaced with a smaller and lighter intarder coupled smaller and lighter intarder coupled to the transmission.to the transmission.


BRAKING SYTEMBRAKING SYTEM

However, ifHowever, if

- EM size is doubled, and- EM size is doubled, and

- power resistors are used to- power resistors are used to

dissipate the energy when thedissipate the energy when the

batteries are fullbatteries are full

there will be no need for the intarder !there will be no need for the intarder !


CONTROL SYSTEM DEVELOPMENTCONTROL SYSTEM DEVELOPMENT A forward looking simulation model is A forward looking simulation model is

developed in Matlab/Simulink, including developed in Matlab/Simulink, including external and internal motion resistances, external and internal motion resistances, load transfer due to trailer loads, detailed load transfer due to trailer loads, detailed clutch and tire models.clutch and tire models.

VEHICLE SENSORS POWERMANAGEMENT

LONGITUDINALVEHICLE DYNAMICS

EM & BATTERYMODELS

DRIVERMODEL

CONTROL SIGNALto

DRIVE INPUT


CONTROL SYSTEM DEVELOPMENTCONTROL SYSTEM DEVELOPMENT

The forward looking simulation model for The forward looking simulation model for the vehicle performance accepts the the vehicle performance accepts the following commands:following commands:

- g- gas pedalas pedal position, position,- b- brake pedal rake pedal position,position,- i- intarder levelntarder level,,- p- pure electric drive switchure electric drive switch state, state,- i- idle charging switch dle charging switch state. state.

These commands can be directly input or These commands can be directly input or may be determined by a driver model may be determined by a driver model to to let the vehicle trace a cycle velocity let the vehicle trace a cycle velocity profileprofile..


CONTROL SYSTEM DEVELOPMENTCONTROL SYSTEM DEVELOPMENT Modes of the rule based control algorithm:Modes of the rule based control algorithm:

EM only driveEM only drive (engine disengaged) (engine disengaged)

- engine runs inefficiently at very low power,- engine runs inefficiently at very low power,- launch up to a certain speed.- launch up to a certain speed.

Engine only driveEngine only drive (EM freewheeling) (EM freewheeling)

- engine runs efficiently.- engine runs efficiently.

Engine+EM driveEngine+EM drive (power summation) (power summation)

- power demand is more than engine - power demand is more than engine capacity.capacity.

Engine+EM driveEngine+EM drive (power split) (power split)

- engine runs inefficiently at high power.- engine runs inefficiently at high power.


CONTROL SYSTEM DEVELOPMENTCONTROL SYSTEM DEVELOPMENT Modes of the rule based control algorithm:

Engine drive + EM chargingEngine drive + EM chargingengine runs inefficiently at low power.- engine runs inefficiently at low power.

RegenerationRegeneration - friction and intarder braking, - friction and intarder braking, - engine braking for zero throttle.- engine braking for zero throttle.

Pure electric drivePure electric drive (if requested by the driver) (if requested by the driver)

Idle chargingIdle charging (if requested by the driver) (if requested by the driver)

!! The selection and application of the control The selection and application of the control rules depend on the battery rules depend on the battery state of charge state of charge (SOC)(SOC)..


CONTROL SYSTEM DEVELOPMENTCONTROL SYSTEM DEVELOPMENT

VEHICLE SENSORS POWERMANAGEMENT

LONGITUDINALVEHICLE DYNAMICS

EM & BATTERYMODELS

DRIVERMODEL

CONTROL SIGNALto

DRIVE INPUT

Control Signals

PC

Control Unit

Driver commands& Vehicle Response


CONCLUSIONSCONCLUSIONS

Difficulty in finding suitably sized hybrid Difficulty in finding suitably sized hybrid components.components.

Difficulty (in terms of time and cost) in Difficulty (in terms of time and cost) in purchasing these components.purchasing these components.

TThe current battery technology is he current battery technology is still still the the most challenging obstacle for most challenging obstacle for the the development of heavy duty hybrid vehicldevelopment of heavy duty hybrid vehicleses due to their weight, volume, and cost. due to their weight, volume, and cost.


CONCLUSIONSCONCLUSIONS With the conclusion of the project study, a With the conclusion of the project study, a

prototype hybrid truck will be available for prototype hybrid truck will be available for further development by road tests and further development by road tests and studies on the control strategies.studies on the control strategies.

The study may be extended for:The study may be extended for:

-- engine shutdown capability.engine shutdown capability.

-- removal of intarder, starter and alternator.removal of intarder, starter and alternator.

-- adaptation to the anti-idling and adaptation to the anti-idling and reduced emission laws.reduced emission laws.

-- application to trucks of differentapplication to trucks of different

classes.classes.


THE ENDTHE END


It was It was foundfound that a battery group of 90Ah that a battery group of 90Ah capacity at 360V operated within 20% state capacity at 360V operated within 20% state of charge (SOC) level (e.g. max 70% - min of charge (SOC) level (e.g. max 70% - min 50% SOC) can feed the electric motor at full 50% SOC) can feed the electric motor at full power for five minutes. power for five minutes.



BRAKING SYTEMBRAKING SYTEM LLegal requirement for braking of egal requirement for braking of

commercial vehicles is stated ascommercial vehicles is stated as : : maintaining the speed of 30 km/h on a 7% maintaining the speed of 30 km/h on a 7% down gradient for a distance of 6 km down gradient for a distance of 6 km without using the friction brakeswithout using the friction brakes. .

Therefore, a secondary system is necessary to fulfill the legal requirement.

november 13, 2008 heavy duty hybrid truck 1 development of a hybrid electric heavy duty truck kemal...

Documents

heavy truck

medium sized hybrid

vehicle performance

em ucap slide

performance objectives

overall fuel consumption

standard truck driving

different configurations