Tutorial 1 

8:00am – 12 :15pm, Monday, September 2009

SiC-BASED POWER DEVICES FOR AUTOMOTIVE POWER CONVERSION APPLICATIONS

 Dr. Burak Ozpineci, Power and Energy Systems Group

Oak Ridge National Laboratory

2360 Cherahala Blvd. Knoxville, TN 37932

Tel:865-946-1329, Fax: 865-946-1262

e-mail:  ozpinecib@ornl.gov

This presentation focuses on the research and development of silicon carbide (SiC) in the area of power electronics for transportation and energy applications.  The theoretical advantages that SiC material offers are being realized by using commercial as well as prototype or experimental devices in many different applications ranging from medium voltage to high voltage. The main advantages of using SiC-based devices are reduced thermal management requirements, higher switching frequency, and smaller passive components which result in higher power density. An overview of the SiC research effort for transportation and utility applications is presented.  The processing of the silicon carbide will be discussed as well as the state of the art in SiC Schottky diodes, MOSFETs, JFETs, BJTs, and other power electronic devices. The advantages of silicon carbide (SiC) power electronics, their application, modeling, and high temperature work will also be presented.

There is a growing demand for more efficient, higher power density, and higher temperature operation of the power converters in automotive applications. In spite of the advanced technology, silicon (Si) power devices cannot meet some power electronics requirements. Silicon carbide (SiC) has been identified as a material with the potential to replace Si devices in the near term because of its superior material advantages such as wider bandgap, higher thermal conductivity, and higher critical breakdown field strength. SiC devices are capable of operating at high voltages, high frequencies, and at higher junction temperatures. Significant reduction in weight and size of SiC power converters with an increase in the efficiency is projected. SiC unipolar devices such as Schottky diodes, VJFETs, MOSFETs, etc. have much higher breakdown voltages compared to their Si counterparts which makes them suitable for use in traction applications replacing Si pn diodes and IGBTs. Presently, SiC Schottky diodes are the most mature and the only commercially marketed SiC devices available. These diodes are commercially available up to 1200V and 50A. SiC Schottky diodes have been experimentally proven to have better performance characteristics when compared to their equivalent Si pn diodes, especially with respect to the switching characteristics. SiC devices can also operate at higher temperatures and thereby result in reduced heat sink volume.

This tutorial is proposed to educate people on the SiC device technology and how it can be applied to power electronics for automotive applications taking advantage of the materials superior characteristics. Some of the subjects to be discussed:

1-      What is SiC? Why is it superior to Si? What other wide bandgap materials are available suitable for power device application? High temperature power converters?

2-      SiC Power Devices and their applications

a.       SiC JFETs

b.       SiC Schottky diodes

c.       SiC MOSFETs

3-      Other experimental SiC power devices such as BJTs, Thyristors, IGBTs, etc.

4-      System-level impact of SiC power devices

a.       pfc circuits

b.       dc-dc boost converters

c.       traction inverters

5-      High temperature packaging and high temperature gate drivers for SiC power devices.

Biography:  Burak Ozpineci (S'92 M'02 SM'05) received the B.S. degree in electrical engineering from the Middle East Technical University, Ankara, Turkey, in 1994, and the M.S. and Ph.D. degrees in electrical engineering from the University of Tennessee, Knoxville, in 1998 and 2002, respectively. He joined the Post-Masters Program with the Power Electronics and Electric Machinery Research Center, Oak Ridge National Laboratory (ORNL), Knoxville, TN, in 2001 and became a Full-Time Research and Development Staff Member in 2002 and the Group Leader of the Power and Energy Systems Group in 2008. Presently, he also has an Adjunct Faculty appointment with the University of Arkansas, Fayetteville. He is doing research on the system-level impact of SiC power devices, multilevel inverters, power converters for distributed energy resources and hybrid electric vehicles, and intelligent control applications for power converters.  Dr. Ozpineci was the Chair of the IEEE PELS Rectifiers and Inverters Technical Committee and Transactions Review Chairman of the IEEE Industry Applications Society Industrial Power Converter Committee. He was the recipient of the 2006 IEEE Industry Applications Society Outstanding Young Member Award, 2001 IEEE International Conference on Systems, Man, and Cybernetics Best Student Paper Award, and 2005 UT-Battelle (ORNL) Early Career Award for Engineering Accomplishment..