48V E-Motor and Inverter

Solutions for CO2 Reduction and Traction AssistThomas Hackl, Magna Powertrain

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What is Driving 48 V?

LegislationEnd Consumers

Global OEMs

Which Functional Trends will Impact 48 V?

Seite 3

• Redundant power source• Enables high computer power• 48 V power actuation -> safety

increase

• No derating of functions• Additional high power functions• Improved Start Stop Comfort

48 V enables much more than only CO2 Reduction

48 V

Increasingnumber of

simultaneousfunctions

Automateddriving

CO2 andexhaust

emission, performance

• 48 V Hybrid• 48 V Turbo charger • 48 V Rear Axle Drive

ChassisComfort

4

48V Motor Generations with high speed concept

Advanced

Gen 1n = 50.000 rpmPpeak = 19kW3,22kW/kg(Benchmark 1,6kW/kg)

Platform development

Gen 2n = 35.000 rpmPpeak = 25kW3,52kW/kg

Scalable platform development

2016 2017 2018 2019 2020

Gen 2 scalablen = 21.000 - 35.000 rpmPpeak = 17 - 25kW

Platform EM D125 EM D153

Stator Outer

Diameter125 mm 153 mm

P4

P3 HPP3 CE

P2.5

P4 co-ax

Stator cooling

Rotor cooling

Advanced development 48V Gen 1 e-Axle

n=50.000 rpmPSM 3 phase Double planet 3-step

gearseti≈60T > 1200 Nm

High speed concept 50.000 rpm with PSM+ High power density / better package / less weight+ Material advantage (magnets, copper, steel)

Challenges of high speed concept-Mechanical stress rotor (LV147)-Sealings-Bearings-NVH gears-Thermal management

PSM concept

Active length 120 mm

Stator OD 97 mm

Rotor OD 54 mm

Air gap 0.5 mm

Poles 4

Stator slots 24

Turns per coil 4

Parallel wires per coil 4

Wire diameter 0.95 mm

PSM concept

Peak torque 22 Nm @ 5.500 rpm

Peak power 19 kW

Max. phase current 500 Arms

Max. operating speed 50000 rpm

Burst speed 70000 rpm (LV147)

Copper weight 0.96 kg

Stator lamination weight 3.33 kg

Rotor lamination weight 1.35 kg

Magnet weight 0.30 kg

Total weight active parts 5.84 kg

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Advanced development 48V Gen 1 motor details

System Test bench

– Function tests

– Performance, efficiency

and drag torque

– Acoustics

– Short durability 230 h

Transmission

– lubrication and breather test

– Back to back durability

Engineering tests / simulation correlations:

– Efficiency and drag torque

– Cooling / thermal management

– NVH

– Rotor dynamics

– Rotor burst done (>70.000 rpm)

Methods fine-tuned for critical topics

All eMotor tests fullfilled functional requirements

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Advanced development 48V Gen 1 e-Axle

Efficiency e-Axle upto 90%

Engineering Methodology

Multi-Objective / Multi-Physics Design Optimization

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• Multi-objective, multi-physics optimization framework

Optimization Objectives:– EMAG design / efficiency / max torque

– Thermal situation / losses

– Mechanics / Rotor strength

– Torque ripple / acoustics

– Dynamic run-up simulation

– Cost model

– Cycle Efficiency

• Highly parallelized direct/genetic/ANN (artificial neuronal network) optimization

• Generate efficiency maps

• Generate motor model for system- and thermal simulation

• Calculate torque ripple as excitation for subsequent NVH simulation

Hybrid genetic and ANN

optimization algorithm

CFD

SPH

Gen 1 Gen 2 platform

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Typical Benchmark GEN 1 GEN 2

Machine TypePSM PSM

3 phasesPSM

6 phases

Max. SpeedCircumferential speed

18.000 rpm85,8 m/sec

50.000 rpm141 m/sec

35.000 rpm141 m/sec

Peak torque 55Nm 22Nm 45Nm

Peak power (gen) 16 kW 19,1 kW 25 kW

Weight (active Parts) 10 kg 5.9 kg 7,1 kg

Power Density(active parts) [kW peak/kg act]

1.6 kW/kg 3,22 kW/kg 3,52 kW/kg

D=

97

mm

D=1

25

mm

Applicationswith hollowshaft

Applicationsw/o hollowshaft

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Application specific part

Interface part w/ platform feature

Common parts

Part categories

• Common parts:

– Inverter

– Motor – active parts

– Planetary gear set – 1st stage

– Decoupling unit

Example offset w/o hollow shaft

Example co-axial with hollow shaft

Gen 2 platform approach

Gen 2: Verification

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Gearbox Durability TestLubrication / Speed Principle Testing Gearbox Lubrication Test

Continuous / Peak Curve Test (75°C cooling water)System Efficiency Test (25°C cooling water)

• Testing performed, high speed bearings and sealings evaluated• Component selection for A-sample build up performed

• Testing in horizontal position and with inclinations performed• Conclusion Rework for satisfactory lubrication / build up of

optimized A- sample units

• Durability run performed successfully• Conclusion ok, gearing strength, load capacity of oil confirmed

• SW parametrization performed• Efficiency map measured with good correlation

• Continuous- and Peak- curve measurement with 48V and 75°Ccooling water temperature performedthermal performance OK

System NVH Testing

• NVH testing performed, results evaluated• Airborne noise compared to specification for electric axle drives

OK• Structure-borne noise vs. spec. slightly outside borderlines

OK

Description

Features/Specifications

ContactInnovation Pillars

eRAD 48 Volt Traction Assist

The 48 Volt torque assist eAxle with a high-speed

eMachine offers significant CO2 reduction potential due to

high recuperation capability and a minimized efficiency

chain.

• Extended Mild Hybrid functions ( Mild Hybrid plus)

due to high power and torque to wheel to touch on

full hybrid functions.

Integrated Decoupling unit for increased torque to wheel

and optimized efficiency.

• Efficiency improvements up to 23% CO2 @ WLTP

• Max. power 25 kW

• Inverter up to 36-52 Vdc, up to 350 Arms

SMARTER CLEANER

BMW 550i with 48V ePower Split

High Performance Transfer Case

• Features/Specifications– BMW 550i

– Engine Type: 4.4 l gasoline

– Engine Power: 340 kW

– Engine Torque: 650 Nm

– Transmission: 8 speed automatic transmission

– Ratio FA: 2.81

– Ratio RA: 3.23

– Magna Powertrain Technology• 48V ePower Split

• High Performance Transfer Case

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Gen 2 Scalability

17kW

17kW

D=1

25

mm

D=1

53

mm

25

kW

25

kW

Gen 2 Scalable:• Package options

• D= 125mm /35.000 rpm• D= 153mm /21.000 rpm

• Co-ax option with hollow shaft• Cooling options EM

• Water• Oil

• Peak power options• 17kW• 25kW

• High speed concept up to 35.000 rpm with PSM

– High power density / better package / less weight

– Material advantage (magnets, copper, steel)

Challenges of high speed concept

– Mechanical stress rotor (LV147)

– Sealings

– Bearings

– NVH gears

– Thermal management

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Gen 2 Scalability Platform decisions

CFDSPH

• Insertion winding

– Very good flexibility scalability

– Low high frequency losses (skin and proximity effects)

– Synergies with MPT HV platform

Challenges of insertion winding

– Maximum torque

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Gen 2 Scalability Platform decisions

• 6 phase control

– Low phase current

– Low capacy of DC link due to low current ripple in DC link

– Robust MosFet load (no parallel MosFets)

– Good scalability up to 25kW

Challenges of 6 phase control

– Control algorithm 2x3 phases

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Gen 2 Scalability Platform decisions

MPT eDS48V Product Overview

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FWD / AWDTransversal Architecture

RWD / 4WDLongitudinal Architecture

eDS48V 4WD HPEM153

eDS48V P4EM153

eDS48V RWD / AWD CE

EM153 & EM125

Platform EM D125 EM D153

Stator Outer

Diameter125 mm 153 mm

Vehicle Segments:B, C, D

Vehicle Segments:C, D, E

Gen 2 scalable

eDS48V P3 CEEM125

7HDT 48V P2.5EM153

MPT eDS48V System Platform

Approach MPT eDS Platform Approach

MPT platform approachconsiders 2 individual geometrical designs with same scalable power requirements. Based on these designs the complete MPT 48V product portfolio will be supplied.

EM125Application: P3aPeak Power: 17 - 25[kW]Dimension (D x L): 125 mmPower Electronics: bolt onCooling: waterStatus: B-Sample

EM153wApplication: P4Peak Power: 17 - 25[kW]Diameter: 153 mmPower Electronics: bolt onCooling: waterStatus: Design Study

EM153oApplication: P2.5Peak Power: 17 - 25[kW]Diameter: 153 mmPower Electronics: separatedCooling: oilStatus: A-Sample

MPT platform approach considers 2 power electronic concepts (bolt on and separated to system). The core components shall be identical for all applications. Costumer interfaces (plugs & housings) will be adapted according costumer requirements.

48.1Power electronic direct attached to system

48.2Power electronic separated from system

• Platform 25kW E-Motor − Peak torque 75Nm

− Max. rotor speed 21.000 rpm

• Platform Power Electronics

• Scalable Gearbox− Gear ratio 16,8 – 21,1

− Max. axle torque 1.200 Nm – 1.500 Nm

− Max. coupled axle speed 995 rpm – 1.250 rpm

• Decoupling (normally open)− Via dog clutch and 48V solenoid for actuation

• Total weight <35kg (oil filled)− Excl. DC cables

− Excl. vehicle bearing rubber

− Excl. side flange shaft with cv-joint

− Excl. bracket for vehicle integration

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eDS48V-P4 co-ax Product Features

System incl. Gearbox (19.5kg)Inverter (4.5kg)

Motor (11.0kg)

48V E-Motor and Inverter

Solutions for CO2 Reduction and Traction AssistThomas Hackl, Magna Powertrain

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