hev emissions testing -.ppt

8/10/2019 HEV Emissions testing -.ppt

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HEV Emissions testing -

J1711 in a nutshell

Sashi VelnatiEmissions and Fuel Economy Cert. Testing

DaimlerChrysler


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Calculations- Basic Assumptions


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Calculations (contd.)


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Regenerative Braking

If the vehicle has regenerative braking, the

regenerative braking system shall be enabled for

all dynamometer testing. An accurate way to

account for the effect of regenerative braking isto test the vehicle on a four-wheel drive electric

dynamometer. Operating a hybrid vehicle with

regenerative braking on a two-wheel drive

dynamometer will generally overstate the effectof regenerative braking by artificially forcing all

braking to occur on the driven axle.


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Optional SOC correction


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Emissions & FE tests

Exhaust Emissions and Fuel Economy TestsThere are two basic kinds ofexhaust emissions and fuel economy tests used in this document.

partially charged RESS (a Partial-Charge Test; PCT)

fully charged RESS (a Full-Charge Test; FCT)

There are variations of these tests depending on which mode of operation is being

tested and which driving schedule is being used.

The PCT has a variation for HEV Operating Modes and another variation for CVOperating Modes.

The FCT has a variation for HEV Operating Modes and another variation for EVOperating Modes.

a. Partial-Charge Test for HEV Operating Modes (PCTHEV)

b. Full-Charge Test for HEV Operating Modes (FCTHEV)

c. Partial-Charge Test for CV Operating Modes (PCTCV)

d. Full-Charge Test for EV Operating Modes (FCTEV)


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Battery Terminology

RATED AMPERE-HOUR CAPACITY - The manufacturer-rated capacity ofa battery in Ampere-hours obtained from a battery discharged at themanufacturer's recommended discharge rate such that a specified minimumcut-off terminal voltage is reached.

BATTERY STATE OF CHARGE (SOC) - The measured capacity of a

battery, expressed in Ampere-hours (A-h). It may also be expressed as apercent of the battery's maximum-rated A-h capacity.

C/3 CURRENT RATE - The constant current (Ampere-hours) at which thebattery can be discharged from its rated Ampere-hour capacity in 3 h to itsmanufacturer's recommended minimum. The C/3 current rate can be usedto verify battery condition.

CUT-OFF TERMINAL VOLTAGE - The manufacturer-recommendedminimum voltage as a function of load

under which battery damage could occur


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SOC Terminology

SOCuidentifies a SOC value during the UDDS (CITY)

SOCh identifies a SOC value during the HFEDS (HIGHWAY)

SOC6identifies a SOC value during the US06 driving schedule

SOC3 identifies a SOC value during the SC03 driving schedule

For each of these driving schedules, there are additional SOC terms:

SOCu initialidentifies the SOC at the beginning of the first UDDS in a Partial-Charge Test (PCT)

SOCu finalidentifies the SOC at the end of the last UDDS in a PCT.

SOCh initialidentifies the SOC at the beginning of the first HFEDS in a PCT.

SOCh pauseidentifies the SOC at the beginning of the second HFEDS in a PCT. The term pause referstothe 15-s pause between the first and second HFEDSs.

SOCh finalidentifies the SOC at the end of the last HFEDS in a PCT.

SOC6 initialidentifies the SOC at the beginning of the first US06 in a PCT.

SOC6 pauseidentifies the SOC at the beginning of the second US06 in a PCT. The term pause refers to

the 1- to 2-min pause between the first and second US06s. SOC6 finalidentifies the SOC at the end of the last US06 in a PCT.

SOC3 initialidentifies the SOC at the beginning of the first SC03 in a PCT.

SOC3 pauseidentifies the SOC at the beginning of the second SC03 in a PCT. The term pause refers tothe 10-min soak between the first and second SC03s.

SOC3 finalidentifies the SOC at the end of the last SC03 in a PCT.


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PCT-HEV


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PCT-HEV (cont..)


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PCT Details

Purpose of TestThe purpose of the PCTHEV is to measure the exhaust emissions

and fuel economy of an HEV over one or a series of driving schedules in an HEV Operating Mode,while representing the

charging habits of the driver who never supplies off-vehicle charge to the RESS.

ApplicabilityThe PCTHEV applies only to HEV Operating Modes.

Test ProductThe following information will be the product of this testing:

a. Exhaust Emissions and Fuel EconomyThe exhaust emissions and fuel economy of the HEVshall be measured during each test phase in which such measurements are required.

b. Actual Distance TraveledThe actual distance that the dynamometer roll surface traveled shallbe measured during each test phase in which such measurements are required.

c. SOCThe state of charge of the RESS shall be measured at various points in the test in orderto ensure that specified SOC requirements are met.


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UDDS Testing

UDDS Test Procedure, HWY has the same rules

Vehicle Preconditioning - The vehicle shall be preconditioned in the driver-selected operatingmode in which it will be tested. The preconditioning is subject to the requirements of 40 CFR Part86.132, which includes fuel tank drain-and-fill, driving over the UDDS, and a 12- to 36-h vehiclesoak. It is the intent that the RESS provide a minimal contribution toward vehicle propulsion duringpreconditioning.

This intention may be satisfied by initially setting the SOC of the RESS to a level for which the netchange in SOC is equal to or greater than zero over the preconditioning cycle. If, however, it isnot possible to prevent a net decrease in SOC during preconditioning, then the SOC shall beset attempting to minimize the decrease.

Initial SOC - After vehicle preconditioning and while the vehicle is soaking, the SOC of the RESSshall be adjusted to SOCuinitial attempting to achieve SOCufinal equal to SOCuinitial (refer to 3.6for state-of-charge terminology). However, if the only way to adjust the SOC is by operating

the vehicle and the desired SOCuinitial is not achieved at the end of preconditioning, thenany further SOC adjustments shall be made after vehicle preconditioning, and the soakperiod shall begin immediately after the adjustments are made.


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UDDS calculations

Exhaust Emissions Calculations for the UDDS Test Procedure of the PCTHEV - The exhaustemissions data from the first UDDS shall be weighted differently than the results from the secondUDDS, to account for cold/hot-start weighting

YPCTHEV,h = Weighted mass emissions of a particular measured pollutant (e.g., HC, CO, NOx,CO2), in grams per mile in the hth HEV Operating Mode

YUDDS(1) = Mass emissions are measured during the first UDDS, in grams

DUDDS(1) = The measured driving distance during the first UDDS, in miles

YUDDS(2) = Mass emissions are measured during the second UDDS, in grams

DUDDS(2) = The measured driving distance during the second UDDS, in miles

The calculations specified in 40 CFR Part 86.144-94(b)-(e) shall be used in conjunction withabove Equation in measuring each individual pollutant, where appropriate.


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US06 (SC03) Testing

US06 Test Procedure

Vehicle PreconditioningThe consumable fuel shall be drained and the tank refilled unless 1) thevehicle underwent another PCTHEV (in any driving schedule) within the last 72 h in the samedriver selected operating mode as to be tested in the US06 Test Procedure and 2) the vehicle hassince remained under ambient laboratory conditions. No other vehicle preconditioning isnecessary for the US06 Test Procedure.

Initial SOCAfter vehicle preconditioning, if any, the SOC of the RESS shall be adjusted toSOC6initial (subject to the charging requirements of 4.1.2.4) attempting to achieve SOC6finalequal to SOC6pause (refer to 3.6 for state of charge terminology). Adjusting the SOC byoperating the vehicle before the test begins is acceptable.

The challenge in meeting the previous requirement (that is, to attempt to maintain a level SOCover the second US06) is to choose the right value for SOC6initial. However, in addition to thischallenge, it is also the intent of this test that the vehicle be adequately preconditioned throughCFEC operation before the second US06 begins. Therefore, in choosing the initial SOC, it is

recommended (but not required) that SOC6initial be equal to or less than SOC6pause to ensurethat the contribution of the RESS toward vehicle propulsion during the first US06 is minimized.

However, if the only way to achieve SOC6final equal to SOC6pause is by setting the SOC6initialto a level that is not expected to occur under normal operating conditions with no off-vehiclecharging (e.g., 0% SOC or 100% SOC), then SOC6initial shall be set to a level that is equal to orless than the level of SOCuinitial from the UDDS Test Procedure of the PCTHEV with the sameHEV Operating Mode. In this case, the SOC Net Change Tolerances shall not apply.


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HFEDS, US06 and SC03

calculations Exhaust Emissions Calculations for the HFED, US06 and SC03 Test Procedures of the PCT

HEV

HFEDS will be substituted with US06 and SC03 for respective tests

YPCTHEV,h = Weighted mass emissions of a particular measured pollutant (e.g., HC, CO, NOx,CO2), in grams per mile in the hth HEV Operating Mode

YHFEDS(1) = Mass emissions are measured during the first UDDS, in grams

DHFEDS(1) = The measured driving distance during the first UDDS, in miles

YHFEDS(2) = Mass emissions are measured during the second UDDS, in grams

DHFEDS(2) = The measured driving distance during the second UDDS, in miles

The calculations specified in 40 CFR Part 86.144-94(b)-(e) shall be used in conjunction withabove Equation in measuring each individual pollutant, where appropriate.


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US06 & SCO3Test Validity

Test ValidationBoth US06 and SC03

tests are considered invalid if the

difference between SOC6finaland

SOC6pauseviolates the SOC NetChange Tolerances.

The criterion for HFEDS (Hwy) however

remains the same as UDDS, SOC6finaland SOC6initial

hev emissions testing -.ppt

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