ORNL is managed by UT-Battelle, LLC for the US Department of Energy

3D Printing for Power Electronics and Electric Motors

Burak Ozpineci

Leader, Power Electronics and Electric Machinery Group

Manager, Electric Drive Technologies Program

Email: burak@ornl.gov

Phone: 865-946-1329

22

DOE EDT Technical Targets

Power Electronics (PE)

($/kW) (kW/kg) (kW/l)

7.9 10.8 8.7

5 12 12

3.3 14.1 13.4

Electric Motors (EM)

($/kW) (kW/kg) (kW/l)

11.1 1.2 3.7

7 1.3 5

4.7 1.6 5.7

Traction Drive Systems (TDS)

Reduce Cost

Reduce Weight

Reduce Volume

Reduce Energy Storage

Requirements

YearCost

($/kW)

Specific Power

(kW/kg)

Power Density(kW/l)

Efficiency (%)

2010* 19 1.06 2.6 >90

2015** 12 1.2 3.5 >93

2020 8 1.4 4.0 >94

Traction Drive System Requirements: 55 kW peak power for 18 sec; 30 kW continuous power; 15-year life

Impact

Power electronics (APEEM - separate targets)

Electric propulsion system components

Traction Drive System (APEEM)

Not in the program

BatteryOn-Board

Battery

Charger

Bi-directional

Converter

Electric

MotorInverter

DC-DC

Converter

Ancillary

Loads

120 V AC/

240 V AC

Fast

Charger

* 2010 traction drive system cost target met with GM integrated traction drive system; 2015 weight and size targets were also met

** 2015 power electronics cost, power density, and specific power targets met with Delphi advanced inverter with integrated controller

ORNL was one of the main contributors to the Delphi inverter

33

EETT R&D Targets and Status

Current Status$1800*

($12/kW 2015 Target)

2025+$900

($6/kW 2025 Target)

Chevrolet Bolt Future Mobility Design Concept

* Based on 2016 Bolt 150 kW system

Our roadmap defines the pathway to achieving 2025 targets

2025 Targets

Cost ($/kW) 50% reduction

Power Density

(kW/L)

843% increase

Power Level 100% increase

Reliability/lifetime 100% increase

Roadmap: https://www.energy.gov/sites/prod/files/2017/11/f39/EETT%20Roadmap%2010-27-17.pdf

4

Why 3D Printing (Additive Manufacturing- AM)?

• Complexity is free

• Less wasted material.

• Quick prototyping

• Integrated functionality/components

• Reduced part count

• Better designs

55

Examples

66

3D Printing for Power Electronics

• Materials for 3D Printing• Polymers

ABS , Ultem, CF-ABS

• Metals

Titanium, Aluminum, Stainless Steel,

Copper, Brass

• Ceramics

Possible 3D printed components• Heat sinks

• Bus bars

• PCBs

• Packages/Modules

• Inductor cores

• Housing

Multi-material printing is still challenging !

• Rapid prototyping

• Complex structures allowing better-designed, more-

complex cooling systems

• Elimination of interfaces

• More integrated functions and components

• Reduction in component count

• More degrees of freedom: Better optimization

7

1200 V, 100 A SiC MOSFET

single phase module layout

designed at ORNL

Single phase

module gate

driver

ORNL 3D printed

power module design

Power density : 10 kW/1.2 L = 8.1 kW/L

~ 3.1 times higher than the commercial module based design

3D Printed Liquid-Cooled 10 kW Inverter

Multi zone integrated heat sink

built with AM techniques for

increased power density of

traction drive inverter.

Initial proof of concept – subset

pieces made in plastic first,

then aluminum

Chinthavali et. al WiPDA 2014

88

Inverter Assembly

Air cool inverter - 3D Layout Air cool inverter - Prototype

Three sets of phase-leg power modules with 3D-printed heat sinks are fabricated to build

a three phase voltage source inverter.

A dc link busbar with six 40 µF film capacitors is designed to obtain a high form factor.

An air duct is designed and installed at the input and output of heat sinks for low air

pressure drop.

99

Rapid Prototyping for Converters and Inverters

Designed and built a power module based

on a small DBC phase leg, designed a

copper base, and designed a 3D printed

ABS lead frame & package.

Packaging and housing was designed

and 3D printed in-house for this all SiC

Inverter

1010

Inverter Module Lead Frames

• Ultem was chosen in order to

withstand the high temperatures

from soldering.

• The lead frame functions as a “jig”

for ease of assembly, but also is used

to mount the DC and AC tabs, and

mount the DBC firmly to the heat

sink.

11

All-SiC Power Module for Boost Converter 3D Printed Housing DesignKey features implemented

• Custom designed and 3D printed housing for simplified encapsulation process, reliable mechanical supporting, easy power terminals and gate drive integration.

• Evenly distributed force around the power module for good contact with base plate and heat sink and thus low thermal resistance.

Gate Drive Board

Power ModuleHousing

Power module 3D mechanical layout design Fabricated power module

First WBG power module with integrated gate driver based on 3D printing technology

SiC MOSFET (bare die)

SiC Diode(bare die)

Power TerminalGate pinout

1212

Thermal Optimization Parts

13

Genetic Algorithm for 3D Printed Heat Sink Design

Wu, Ozpineci, et.al. APEC 2016

1414

Analysis – Case 1

Laminar Flow Region:

Cooler liquid, Fast distribution

to the bottom

Turbulent Flow Region:

Take advantage of the

liquid, stay longer with

more concentrated channels

90.65°C 68.37°C

22 °C lower junction temperature 30% improvement

Wu, Ozpineci, et.al. APEC 2016

1515

Analysis – Case 2

Outlet

Inlet

141.54°C 102.09°C

Key features:• By-pass channel• “#” target channels• Fewer channels- more concentrated

39.5 °C lower junction temperature 35% improvement

Wu, Ozpineci, et.al. APEC 2016

1616

Material Composition [3]

Aluminum 6061

AdditiveManufactured

Aluminum

Wu, Wereszczak, et.al. 3D-PEIM 2016

1717

Material Composition

Aluminum 6061

AdditiveManufactured

Aluminum

Wu, Wereszczak, et.al. 3D-PEIM 2016

1818

Solution – Post-processes

Annealing Point

- Over the annealing point, the thermalproperty of the Al_AM will permanentlychange, and the gap of material propertiesis erased.

- Rough surface need to be polished atthermal interface layer. However, theroughness can additionally increase thethermal convection performance.

Wu, Wereszczak, et.al. 3D-PEIM 2016

1919

Wall-layout

Cell distribution

Heat Sink Individual

1 2 3 4 5 6 7 8 9

Available types of cell pattern and corresponding numbers:

Meshed design space

Cells

With a wall

Without a wall

“Wall” definition:

Symmetric design

Air-Cooled Heat Sink Design Approach – Cell Matrix Optimization

Wu, Ozpineci, et.al. ITEC 2018

2020

Crossover

Mutation

Mating poolOffspring

Genetic Algorithm Process (Crossover and Mutation)

21

Comparisons

Custom Manufactured

Dimensions: 62mm×36mm×32mm

Surface area: 52840.0 mm²

3D Printed

Dimensions: 57mm×36mm×27mm

Surface area: 55200.0 mm²

Heat Side

15% improvement

in terms of Power density

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Temperature Profile

Custom Manufactured 3D Printed Max junction temperature: 109.3°C

Max junction temperature: 102.0 °C

10% improvement in terms of Thermal

resistance

Wu, Ozpineci, et.al. ITEC 2018

23

Air-cooled heat sink applications

Wu, Ozpineci, et.al. ITEC 2018

2424

3D Printed Air-Cooled 50-kW Inverter Heatsink2015

2016 6 kW/l

Fan

Gate driver 3D printed

Alpha-power block

3D printed air duct DC link capacitor

AC output

DC busbar and input

Mounting

bracket

Heat sink

Chinthavali, et.al. APEC 2018

25

3D Printed Electric Motors

Redesigning the modern motor.

• Complex rotor and stator

structures that can only be

manufactured using 3D

printing.

• Steel grain orientation control

Challenges:

• Printing multiple materials

together

• Laminations or no laminations:

opportunity to eliminate many

manufacturing steps

26

3D Printed Electric Motors

Stator 3D printed with steel,

conventionally wound.

Completed

pieces inserted in

3D printed

housings

Complete

functional

unit

Rotor mag core printed with steel, cast

rotor bars and end rings.

2727

Schematic Illustration of the BAAM Process

MQP isotropic

powder

Nylon-12

Mix, melt

and

extrude

Composite pellets:

65 vol % MQP+ Nylon

BAAM

3D printing

Additively printed

NdFeB bonded magnets

Li, L. et al., Sci. Rep. 6, 36212 (2016)Magnetic Moments, The Economist, Nov. 19, 2016

2828

Big Area Additive Manufacturing (BAAM) of Isotropic NdFeB Nylon Bonded Magnets

Why AM? No tooling required, cost effective

Minimum critical material (rare earth) waste

Rapid prototyping

No limitation in sizes and shapes

(BH)max = 5.31 MGOe; Density = 4.9 g/cm3

-5 -4 -3 -2 -1 00

1

2

3

4

5

6

32

34

36

38

40

42

44

300 320 340 360 380 400

4.0

4.4

4.8

5.2

5.6

BH

(M

GO

e)

H (kOe)

BAAM

(B

H)m

ax

(kJ/m

3)

(BH

)max

(M

GO

e)

T (K)

Li, L. et al., Sci. Rep. 6, 36212 (2016)

2929

Big Area Additive Manufacturing (BAAM)

Source: Ling Li, Angelica Tirado, I.C. Nlebedim, Orlando Rios, Brian Post, Vlastimil Kun, R.R. Lowden, Edgar Lara-Curzio, Robert Fredette, John Ormerod, Thomas A. Lograsso, and M. Parans Paranthaman, “Big Area Additive Manufacturing of High Performance Bonded NdFeB Magnets,” Nature: Scientific Reports (2016).

3030

Successful Demonstration of AM Printed NdFeB Magnets in a DC Motor Configuration

This work has demonstrated the potential of using additively printed NdFeB magnets instead of sintered ferrite magnets in motors

Original motorNew motor

With printed magnet

Jason Pries

3131

Applications – AM NdFeB Magnets in a DC Motor Configuration

Original motorNew motor

With printed magnet

3232

• Additive manufacturing is an enabling technology for design of next generation power electronics and electric motors.

• Emerging materials and integration techniques (e.g. multi-disciplinary optimization) have to be blended into the design and development to reach 100 kW/L power density target.

Conclusion

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Questions

3434

Questions