POWERTRAIN SOLUTIONS FOR AVL ELECTRIFIED TRUCKS AND BUSES

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


TRUCK & BUS ELECTRIFICATIONDRIVERS

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

CO2

URBAN ACCESS REGULATIONS IN EUROPE

FOCUS

OF CURRENT

PRESENTATION

http://www.google.at/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwiFzISE077PAhXCtBQKHde_AEYQjRwIBw&url=http://electrek.co/2016/07/27/daimler-etruck-first-all-electric-truck-125-miles-range/&psig=AFQjCNHYdYzff_W8btEarQZscQZa3uamqg&ust=1475584561249804


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


Modular Battery

Integrated Electric Axle

CONTENT


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


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


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


BEST COST AND HIGHEST FLEXIBILITY BY MODULAR RACK DESIGN

CoolingPlates

RackStructure

LargeRack

SmallRack

Scalable and modular pack concept


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


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

]


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


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


Modular Battery

Integrated Electric Axle

CONTENT


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


0

4

8

12

16

20

24

28

32

36

0 10 20 30 40 50 60 70 80 90

Grad

eab

ilit

y [

%]

Velocity [kph]

Gross Vehicle Weight: 16 tons

0

4

8

12

16

20

24

28

32

36

0 10 20 30 40 50 60 70 80 90

Grad

eab

ilit

y [

%]

Velocity [kph]


0

4

8

12

16

20

24

28

32

36

0 10 20 30 40 50 60 70 80 90

Grad

eab

ilit

y [

%]

Velocity [kph]


gear 2 (cont.)

gear 1 (cont.)

0

4

8

12

16

20

24

28

32

36

0 10 20 30 40 50 60 70 80 90

Grad

eab

ilit

y [

%]

Velocity [kph]


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


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


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


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


▪ 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


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


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


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

0

4

8

12

16

20

24

28

32

36

0 10 20 30 40 50 60 70 80 90

Grad

eab

ilit

y [

%]

Velocity [km/h]

2nd gear - continuous

1st gear - continuous

2nd gear - peak

1st gear - peak

Vehicle Performance - 16 ton Truck (4x2)


▪ 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


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


ZERO-EMISSION SOLUTIONS FOR URBAN TRANSPORT

THANK YOU FOR YOUR ATTENTION

Documents

POWERTRAIN SOLUTIONS FOR AVL ELECTRIFIED TRUCKS AND BUSES