EVS28KINTEX, Korea, May 3-6, 2015

Power Rating of Hybrid ElectricPower Rating of Hybrid Electric Vehicles for Vehicle Classification

Dongseok Choi1, Kihyeon Ryu, Jaewan Lee and Jaeseung Shin1Author 1 (corresponding author) TS Korea Automobile Testing and Research Institute, ( p g ) g ,

200 Samjon-Ro, Songsan-Myun, Hwasung-Si, Gyeonggi-Do, 445-871, dsechoi@ts2020.kr

Introduction

Current situation>- Mass production of HEVs and PHEVs for energy efficiencyp gy y- Increased Electric Fraction of (P)HEVs for longer EV range- Clear demand from WLTP-SG-EV (P-to-M ratio, Downscaling Method, Gear Shift Model)

Problems>- Representative power for HEVs and PHEVs- Vehicle classification and Taxation (vehicle occupation tax)Vehicle classification and Taxation (vehicle occupation tax)- Not defined terminology on (P)HEV’s power

Suggested solution>Suggested solution>- Concept of system power

2

Motivation – Concept of system power

“What is the system power? “ The power is measured at the end side of the powertrain

without tires. The power obtained the relationship between wheel torque

and ehicle speedand vehicle speed.PowertrainEnergy Storage

Energy Converter(ICE, E-Motor, Fuel cell, …)

Drivetrain

Wheel torque Wheel torque

3

Wheel torque Wheel torque< Defined by UN/WP.29/GRPE/ VPSD IWG >

Objective“ System power ”

HEVsICE power E-Motor power

E-MotorICE

P, T

P

, T

E MotorICE

P

T T

P

Vehicle

P

T

P, T

P, T T

VN N

d

4

V : vehicle speedN : speedP : power T : torque

Background – Related standards

SAE J1491 : Vehicle Acceleration Measurement (2006)- Measuring launch response and acceleration performance- Passenger cars and light-duty trucks- Field test procedure- Uncertainty about test result- Uncertainty about test result-- Effect of ambient conditions on tire pressure and temperature-- Track coefficient of static and dynamic friction-- Non standard instrumentation-- Driver difference-- Track temperature

SAE J2908 : HEV System Power Ratings (on going)P i i (Wh l d P )

-- Track temperature

- Powertrain power rating (Wheel torque and Power)- Electric assist- Electric-only power rating

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Electric only power rating- Regen power rating

Powertrain test bed Test bed

Dynamometer spec.• Max power : 290 kW @1100 ~ 3000 rpm• Max torque : 2500 Nm @ ~ 1100 rpm

(40% overload : 3500 Nm)• Wheel base : 1.8 ~ 3.8 m

Control jig for accelerator pedal

• Thread : 1.2 ~ 2.2 m

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Test vehicles

Specification of powertrain for test vehicles

ItemsTestVehicles

PowerDrivetrainType

Electric Fraction(EF)

[%]ICE[kW]

E-Motor[kW]Vehicles [%][kW] [kW]

HEV 1 133.2 15 AT(6) 10.1

HEV 2 110.4 30 AT(6) 21.4

HEV 3 72.9 60.4 e-CVT 45.3

PHEV 72.9 60.4 e-CVT 45.3

HEV 4 116.3 105.2 e-CVT 47.5

EF =Motor power

(ICE power + Motor power)X 100

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Development process

x,

V max

V min

V hi l i Test c cleVehicle warming Test cycle

ssin

g ta

pro

ces

8

Da

Test procedure and test method

@ 90 ± 10 km/h for 20min

@ 90 ± 10 km/h for 10min

RLadapted = RLtrack – Fpowertrain loss

9

Determination of max system power How to determine max system power?

: 5% error bar

Criterion for max power : < COV 2%

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Criterion for max power : < COV 2%

Test result of HEV 1 (EF = 10.1%)Max. power : 103.4 kW

ICE (133.2 kW) AT Wheel

Motor (15 kW)

Belt

Test No.

MaxSystem

M.S.Pdifference

Vehicle Speed

V.S.difference

Power (kW) (%) (km/h) (%)

1 103.4 -0.4 139 0.5

2 103.0 -0.8 137 -1.0

3 105.0 1.2 139 0.5

Avg. 103.8 - 138 -

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Test result of HEV 2 (EF = 21.4%)

Max. power : 103.2kWICE (110.4kW)

Motor(30kW)AT Wheel

Test No.

MaxSystem

M.S.Pdifference

Vehicle Speed

V.S.difference

Power (kW) (%) (km/h) (%)

1 102.4 -0.4 147 0.7

2 102.7 -0.1 146 0.0

3 103.2 0.4 145 -0.7

Avg. 102.8 - 146 -

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Test result of HEV 3 (EF = 45.3%)Max. power : 74.4kWICE (72.9 kW)

Motor (60.4 kW)e-CVT Wheel

Test No.

MaxSystem

M.S.Pdifference

Vehicle Speed

V.S.difference

Power (kW) (%) (km/h) (%)

1 74.1 -0.1 139 0.2

2 74.1 -0.1 137 -1.2

3 74.4 0.3 140 1.0

Avg. 74.2 - 139 -

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Test result of PHEV (EF = 45.3%)Max. power : 78.9kWICE (72.9 kW)

Motor (60.4 kW)e-CVT Wheel

( )

Test No.

MaxSystem

M.S.Pdifference

Vehicle Speed

V.S.difference

Power (kW) (%) (km/h) (%)

1 78.9 0.3 150 -1.7

2 78.5 -0.2 156 2.2

3 78.6 -0.1 152 -0.4

Avg. 78.7 - 153 -

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Test result of HEV 4 (EF = 47.5%)Max. power : 119.7kWICE (116.3 kW)

Motor (105 2 kW)e-CVT Wheel

Motor (105.2 kW)

Test No.

MaxSystem

M.S.Pdifference

Vehicle Speed

V.S.difference

Power (kW) (%) (km/h) (%)

1 119.7 0.6 117 2.0

2 115.6 -2.9 113 -1.5

3 121.8 2.3 114 -0.6

Avg. 119.0 - 115 -

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Conclusions and future work

Conclusions

System power means the power is measured at the end side of the powertrain without a tire.

For the determination of max system power, the criterion was the less than COV 2%.

The test procedure for system power measurement was developed and the test result had a good repeatability within ±3 percent.

Future work To validate the test procedure for various types of vehicles such as

plug-in hybrid vehicles and electric vehicles with in-wheel motors

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p g y

Acknowledgements

This research was supported by the Ministry of Land, Infrastructure and Transport.It was also supported by the Korea Agency for Infrastructure Technology AdvancementIt was also supported by the Korea Agency for Infrastructure Technology Advancement

(Project No. : 13PTSI-C054118-05).

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