H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 1Public

POWERTRAIN SOLUTIONS FOR

ELECTRIFIED TRUCKS AND BUSES

PDiM 2017

(Heimo Schreier)Burak Aliefendioglu

Fredrik Haag

AVL

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 2Public

TRUCK & BUS ELECTRIFICATIONDRIVERS

GHG / CO2 LIMITS ZERO NOISE / EMISSION DRIVING IN CITY ZONES

CO2

URBAN ACCESS REGULATIONS IN EUROPE

FOCUS

OF CURRENT

PRESENTATION

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 3Public

NEXT GENERATION ELECTRIC TRUCKS WILL CONSIST OF SPECIFIC E-POWERTRAIN

Increasing Production Volumes

Integration of existing components

▪ Low development cost▪ Low validation cost▪ Low production investment▪ Higher product cost

Specific component developments (battery & e-axle)

CURRENT PRODUCTS

NEXT GENERATION

▪ Low product cost▪ Medium development cost▪ Medium validation cost▪ Medium production investment▪ Value-creation in-house

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 4Public

Modular Battery

Integrated Electric Axle

CONTENT

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 5Public

BATTERY CHALLENGES IN TRUCK & BUS APPLICATIONS

Charging @ >> P

Discharging @ >> P

Cell Technology

PackDesign

ThermalManagement

BMS

Durability

Volume

Weight

Cost

Range

Energy

Modularity & Scalability

VehicleIntegration

CrashRequirements

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 6Public

BATTERY CELL TECHNOLOGY

SOP Wh/kg Wh/L

2015 175 - 225 400 - 500

2020 225 - 275 500 - 600

2025 275 - 325 600 - 750

Performance Prognosis of Li-Ion Cells

▪ Li-Ion will remain major technology by mid-term

▪ Li-Sulfur might be an interesting alternative in future

Trends for Automotive-Cell Technology

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 7Public

BEST COST AND HIGHEST FLEXIBILITY BY MODULAR RACK DESIGN

from cell to moduleRACK SYSTEM ENABLES:▪ Scalability▪ Modularity▪ Ease of assembly▪ Re-usability with different

modules▪ Flexible pack design and

vehicle integration

(a) Longitudinal (b) Transverse (c) Sideways (d) Inverted

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 8Public

BEST COST AND HIGHEST FLEXIBILITY BY MODULAR RACK DESIGN

CoolingPlates

RackStructure

LargeRack

SmallRack

Scalable and modular pack concept

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 9Public

E/E CONCEPT MODULARITY IN VOLTAGE AND ENERGY

Configuration with 432 cells

36 modules in series with 12 cells each

6S2P = 800V

3S4P = 400V

Configuration with 864 cells

72 modules in series with 12 cells each

3S4P = 800V

5x + 3x

3x

VARIABLE MODULE CONFIGURATION ALLOW EASY VOLTAGE ADJUSTMENT12S1P - 6S2P - 4S3P - 3S4P

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 11Public

MOST EFFECTIVE COOLING IS KEY FOR HIGH PERFORMANCE BATTERIES

Highway Transport Cycle

• Temperature spread kept <10K

• Pack temperature kept at 30°C

Urban Transport Cycle

• Temperature spread kept <<10K

High Performance Charging

• 15°C increase at 1.5C charge rate

Vehicle Load Cycle

System Simulation

Battery System Response

THERMAL SİMULATİON RESULTS

REQUIRES PRECISE

THERMAL MANAGEMENT

& SMART CONTROLS

Current [A] Electrical Power [kW] SoC [%] Voltage [V]

Cell

Tem

peratu

re [

°C

]

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 12Public

MODULAR BATTERY MANAGEMENT SYSTEM

AVL MCU & AVL BMS (3rd generation)

▪ MOST ACCURATE BATTERY/CELL STATE CONTROL - for highest performance & durability

▪ MODULAR PLATFORM & MODEL BASED CONTROLS – for efficient handling of variants

▪ FLEXIBLE ADAPTION TO CUSTOMERS REQUIREMENTS including open-source SW

Function Overview – AVL BMS

CORE BATTERY FUNCTIONS

▪ State of Charge (SOC)

▪ State of Health (SOH)

▪ Balancing

▪ State of Function (SOF)

▪ Cell failure / wear detection

AUXILIARY FUNCTIONS

▪ Start-up / Shutdown

▪ Signal acquisition / actuator control

▪ Main contactor control

▪ Pre-charge function

▪ Thermal management

INTERFACE & COMMUNICATION

▪ Vehicle interface

▪ Diagnosis interface

▪ Logistic-information

▪ Actuator control (external)

▪ Re-programming

SAFETY & DIAGNOSIS

▪ Isolation detection

▪ HV interlock

▪ Safety monitoring

▪ Diagnosis functions

▪ Error-management

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 13Public

EXAMPLES OF A BATTERY PACK FAMILY FOR LD & MD TRUCK

LD Pack

MD Pack

Number of modules - 36 72

Module configuration - 6S2P 3S4P

Cell weight kg 374 748

Pack weight kg 575 1.150

Nominal voltage V 800 800

Installed energy kWh 112 223

Usable energy kWh 78 156

Power – continuous kW 235 420

Power - peak kW 400 715

LD Battery Pack112 kWh

MD Battery Pack223 kWh

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 14Public

Modular Battery

Integrated Electric Axle

CONTENT

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 15Public

SELECTION OF E-AXLE ARCHITECTURE

OBJECTIVES / BOUNDARIES:

▪ Small packaging space for battery

▪ High system efficiency avoid bevel-gear set

▪ Low cost & weight

▪ High integration level

▪ Low number of interfaces reliability, assembly complexity

Center Drive

Axle Integrated

Drive

WheelSelective

Drive

Most Suitable e-Axle architectures for HD Truck

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 16Public

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Gross Vehicle Weight: 16 tons

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Gross Vehicle Weight: 16 tons

gear 2 (cont.)

gear 1 (cont.)

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Gross Vehicle Weight: 16 tons

gear 2 (cont.)

gear 1 (cont.)

gear 1 (peak)

▪ Definition of continuous power of E-motor

▪ Gradeability: 2.2% at 80kph

▪ Good performance also for city highways

▪ Resulting continuous power of E-machine: 148kW

▪ Definition of number of gears

▪ Maximum vehicle speed: 88kph

▪ City highways

▪ Reduced E-motor speed for 80kph

▪ Maximum gradeability: 16% + 0.3m/s² acceleration

▪ Relevant urban transport routes

▪ Artificial ramps

▪ Resulting number of gears: 2 gears

SYSTEM SPECIFICATION:E-MOTOR POWER AND NUMBER OF GEARS

2.2%@80kph

max. 18.8%= 16 % + 0.3 m/s² acceleration

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 17Public

SELECTION OF E-MOTOR TYPE

Parameter IM PSM

Power / torque density 0 ++

Overload capability + 0

Cost + -

Robustness ++ 0

Failure torque + -

Efficiency at high speed + 0

Efficiency at mid speed - +++

High Efficiency Areas

Torque

Speed

PSM

IM

PSM technology show overall best performance for this application

Comparison of efficiency maps

Induction vs. Permanent Synchronous Motor

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 18Public

HIGH E-MOTOR PERFORMANCE BY DIRECT OIL-COOLING OF STATOR

▪ E-Motor is typically laid-out / designed for peak power

▪ Continuous power depends on effectiveness of cooling system

▪ AVL direct oil-cooling of stator enables highest continuous-power densities

Uncooled,Free

convection

Aircooled

Water jacket

Forced air

convection

Direct oil-

cooling

Peak Power

Continuous-power output of different cooling concepts

continuous-power output

E-M

oto

r P

ow

er

AVL direct oil-cooling of windings

Integration of AVL e-motor into e-axle

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 19Public

DEFINITION OF E-MOTOR SPEED

Inverter▪ Suitable inverter output

frequency

Transmission▪ Standard components▪ Suitable ratios without

additional gear mesh

E-Motor▪ Low torque => high speed

▪ Low cost▪ Compact packaging

E-Motor

Continuous power (kW) 148

Maximum speed (rpm) 16.000

Continuous torque (Nm) 265

Number of pole-pairs (-) 3

Corner speed ratio (-) 1:3

Inverter

Inverter output frequency (Hz) 800

Transmission

Ratios (1st gear/2nd gear) ~50/30

gear meshes (incl. differential) 3

Technology (bearings, seals) Standard

Balance

of

Parameters

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 21Public

▪ Mechanical and thermal integration for high vibration

environment

▪ Usage of standard semiconductor modules

(1.200 V IGBT, max. 600 A / phase)

▪ High efficiency by specific DC-link capacitor design

▪ Modular / scalable platform

▪ Easy adaption to available packaging

▪ Easy assembly & service

▪ EMC advantages due to bus bar AC- & DC-connections

▪ Transmission control integrated in power electronics

▪ Electronics fully integrated in axle body

(cost, weight and reliability advantage)

INVERTER DESIGN

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 22Public

TRANSMISSION DESIGN

TRANSMISSION OPTIONS:

▪ Layshaft

▪ Planetary

▪ Combination of both

TARGETS / EVALUATION CRITERIA:

▪ Suitable gear ratios

▪ Small packaging / short axial length

▪ Highest efficiency

▪ Lowest cost

▪ Variable arrangement / modularity

Selected Topology:

▪ Layshaft arrangement

▪ 2 speeds

▪ 3 gear meshes

▪ Conventional differential

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 23Public

CHALLENGES:

▪ Different temperature levels required for inverter, e-motor and transmission

▪ Reliable lubrication of high-speed transmission

COOLING & LUBRICATION SYSTEM

Oil Circuit 1 (externally cooled)

Oil Circuit 2

M

Heat transfer to environment

Heat transfer to environment

Heat transfer trough axle body

SOLUTION:

▪ Separate oil circuits for

▪ Lubrication of transmission

▪ Cooling of inverter and e-motor

ADVANTAGES

▪ Optimized component temperatures (Efficiency)

▪ Reliable lubrication of high-speed transmission

▪ High-performance transmission oil possible

▪ Compact design

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 24Public

E-MACHINE

Type PSM

Voltage level [V] 800

Continuous power [kW] 148

Max. continuous torque [Nm] 265

Max. speed [rpm] 16.000

Cooling systemDirect statorOil-cooling

TRANSMISSION

Transmission type Layshaft

Number of gears 2

Max. output torque [Nm] 13.200

148 KW ELECTRIC AXLE FOR 16 TON ELECTRIC URBAN TRUCK

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2nd gear - continuous

1st gear - continuous

2nd gear - peak

1st gear - peak

Vehicle Performance - 16 ton Truck (4x2)

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 25Public

▪ Demand for zero-emission transport solutions will further increase

▪ Next generation e-trucks and e-buses will implement specific CV-systems

▪ Frame-integrated batteries improve crash-safety, cost and weight

▪ Integrated electric axles provide space for battery packaging and improve efficiency, cost and weight

▪ Modularity & scalability is key to cover different applications

CONCLUSIONS

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 26Public

FULLY INTEGRATED E-DRIVE FOR SUVHIGHLY EFFICIENT AND HIGHLY INTEGRATED

SPECIFICATIONS

Highlights ▪ Full integrated power inverter

▪ High efficient oil stator cooling

▪ PSM – high speed concept with 20.000 rpm

▪ EMC optimized

Operating voltage 800 V

Power (cont./peak) 150 kW / 230 kW

Torque (cont./peak) 240 Nm / 360 Nm

Dimensions 544 x 387 x 280 mm

Weight overall (approx.) < 100 kg

Power to weight ratio > 2.3 kW/kg

Cooling concept Oil, water or combined

H. Schreier, B Aliefendioglu, F. Haag | PDIM 2017 | 30 November 2017 | 27Public

ZERO-EMISSION SOLUTIONS FOR URBAN TRANSPORT

THANK YOU FOR YOUR ATTENTION