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BEV POWERTRAIN MODEL VALIDATION

OBJECTIVEVEHICLE CHARACTERISATIONMODEL DECOMPOSITIONINSTRUMENTATION SETUPTEST PLANCOMPONENT CHARACTERISATIONRESULTSDISCUSSIONSIMPACT

AGENDABEV POWERTRAIN MODEL VALIDATION

Bosch Engineering North America | BEG/EPT3-NA | 11/03/2017© 2017 Robert Bosch LLC and affiliates. All rights reserved.

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Systems level validation of a Bosch physics based model

Quantization of accuracy of topology studies for customers

OBJECTIVEBEV POWERTRAIN MODEL VALIDATION

24 kWh

Li-ion

Battery

Power Inverter Module83 kW 3-phase

AC Motor with

Single speed drive

Regenerative Brake Module


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Brake controller

Vehicle Controller

Energy Storage SystemPower Electronics

Model

Transmission Model

Vehicle Model

Driver Model

Auxiliary Power Consumption

VEHICLE MODEL CHARACTERISATIONBEV POWERTRAIN MODEL VALIDATION

Target Creep Speed

Maximum deceleration due to

Regeneration Regeneration Limits

Power-electronics Losses

Accelerator Pedal map

Rolling Resistance


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Battery OCV & Impedance

Battery Current and Power

LimitsMotor Speed and Torque Limits

FD Ratio

CdFrontal AreaTrack

Wheel-base

Auxiliary Power

CoG Height Powertrain

Efficiency

Vehicle mass

Minimum Speed for Regenerative Braking

Brake Blending Velocity

Brake Blending Ratio

MODEL DECOMPOSITIONBEV POWERTRAIN MODEL VALIDATION


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INSTRUMENTATION SETUPBEV POWERTRAIN MODEL VALIDATION


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TEST PLANBEV POWERTRAIN MODEL VALIDATION

ON-ROAD DYNAMOMETER


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BRAKE CONTROLLER Lower threshold for regenerative brake blend out

Regenerative Torque ramp-out rate

Start of blend velocity

Threshold deceleration for regenerative braking

Critical Brake Torque Demand

Regenerative Brake Torque Capacity

BEV POWERTRAIN MODEL VALIDATIONVehicle Speed (kmph)

Start of blend velocity Lower threshold velocity for brake blending

Torqu

e (Nm

)


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BATTERY PACK

Impedance

Using equation,

Vt = Vo - IR

where,Vt = Terminal VoltageVo = Open Circuit VoltageI = CurrentR = Internal Resistance

BATTERY PACKBEV POWERTRAIN MODEL VALIDATION


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VEHICLE CONTROLLER

Creep Velocity

Pedal Mapping

Torque Request Computation

BEV POWERTRAIN MODEL VALIDATION


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Model validation was done over 5 standard drive cycles

Performance metrics analysed:

‒ Energy Consumption (Joules)

‒ Range (km)

RESULTSBEV POWERTRAIN MODEL VALIDATION


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MOTOR POWER

Time (sec)

Powe

r (kW

)


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68.367.0 67.8 67.2

65.1

70.271.4 71.5 71.1 71.9

2.7

6.25.1 5.4

9.5

0.0

5.0

10.0

15.0

20.0

25.0

30.0

30.0

35.0

40.0

45.0

50.0

55.0

60.0

65.0

70.0

75.0

US06 HWFET WLTC NEDC UDDS

Inaccu

racy (

%)

Energ

y (MJ

)

ENERGY CONSUMPTION

Model Actual Inaccuracy



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114.9

163.6155.2

172.5

201.9

109.3

155.2 152.2161.1

182.7

5.2 5.4

2.0

7.1

10.5

0.0

5.0

10.0

15.0

20.0

25.0

30.0

30.0

50.0

70.0

90.0

110.0

130.0

150.0

170.0

190.0

210.0

230.0

US06 HWFET WLTC NEDC UDDS

Inaccu

racy (

%)

Dista

nce (k

m)

RANGE ESTIMATION

Model Actual Inaccuracy



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Systems approach to calibration

Reduced development time by eight to twelve months

Number of prototypes reduced by two - three

Significant cost savings per vehicle program

DISCUSSIONS AND IMPACTBEV POWERTRAIN MODEL VALIDATION


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THANK YOU

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