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

Power ElectronicsTechnology : Current Status

Power Electronics Team LeadOak Ridge National Laboratory

Madhu Chinthavali

2 Madhu Chinthavali

1.7 kV SiC MOSFET-Based 50-kW Air-cooled Inverter

Power Block Gate Driver

Voltage Sensors

Inverter-side Inductors

AC Capacitors

Grid-side Inductors

Controller Board

Power density: 16 W/in3 CEC efficiency: 98. 2% (SOA 97.5% –

98.5%. IEEE 1547 grid support functions

Inverter Power Density : 16 W/in3

SiC MOSFETs (Bare Die )

SiC Diodes (Bare Die )

Heatsink

Power stage Power Density : 75 W/in3

~ 50 % of WBG PE converter system cost and volume: components other than

Semiconductors

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PE Design Framework

Pow

er E

lect

roni

cs

Syst

em

POWER STAGE SUBSYSTEM

SEMICONDUCTORS

MAGNETICS

POWER MODULE CONTROLLERS

CAPACITORS

THERMAL MANAGEMENT SUSBYSTEM

CONTROL & PROTECTION SUBYSTEM

4 Madhu Chinthavali

Limitations of SOA WBG Devices: Scaling the device to realize higher power

Toyota Prius’10Module

[1] L. Tolbert, F. Wang, M. Chinthavali etc. “Wide bandgap devices for electric vehicles”, DOE report

• Current sharing in WBG power modules

• Current density of devices

• Stable operation over a temperature range – smaller die size

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Limitations of SOA WBG Devices: WBG Module Packaging and Thermal Designs

Double-side cooled packages are being pursued as the solution for realizing the attributes of the WBG technology

• Low parasitic and high temperature packages for high voltage devices

• Top metallization needed for die attach

• Localized electric field failures without proper filler material

• CTE mismatch with multi layered structure

• Reliability :Reduced die area size and thickness

• Lack of standards for WBGToyota LS600 Module

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Limitations of SOA WBG Devices: WBG Module Gate Driver and Protection Technology Issues

• Commercially available gate drive solutions are for discrete devices and modules with limited functions

• Also the number of components used will decrease the power density of the system

• Lack of IPM based solutions from device manufacturers• Short Circuit protection for devices and modules• Noise Immunity for high power systems

Requirements for Active Protection Schemes

Single-event Short Circuit

RepetitiveShort Circuit

Noise Immunity

4

6

8

10

12

14

16

350 450 550 650 750 850

tsc (μs)

DC Voltage Vdc (V)

CREE_2G_SCWT @200 oC

Tem

pera

ture

(o C)

0 5 100

200

400

600

800

1000

1200

Time (μs)

-50

150

350

550700

Dra

in-S

ourc

e (V

)

200-202468

10

Time (ns)

100 800 900Det

ectio

n Si

gnal

(V)

ProtectionThreshold

CREE_2G @25 oC

[1] Z. Wang, 2015.

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• Several layers control required to co-ordinate multiple power stages

• Fast switching WBG devices : the time scales at different layers challenge

• Adapting the control to grid standards

Limitations of SOA WBG Devices: Control

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Interconnects, Breakers and Sensors

Auxiliary power supply(isolated) : 1000 V -24 V dc

AC/DC Contactorsfor >1 kV

High bandwidth high voltage Sensors > 1 kV,High current

Terminal blocks AC/DC

High voltage Bus-Bars, Connectors & Fuses

9 Madhu Chinthavali

DOE-OE Gap Analysis: Structure and Example• Identify gaps and synergies for

different PE applications• Sponsored by DOE-OE: Kerry

Cheung• ORNL and SNL joint effort

Example of Semiconductors

(voltage, current, and switching frequency

range )

Pow

er E

lect

roni

cs S

yste

m

POWER STAGE SUBSYSTEM

SEMICONDUCTORS

MAGNETICS

POWER MODULE CONTROLLERS

CAPACITORS

THERMAL MANAGEMENT SUSBYSTEM

CONTROL & PROTECTION SUBYSTEM

10 Madhu Chinthavali

Thank you !