Comparative Evaluation of Three-Phase Si and SiC AC-AC Converter Systems

420 Pages·2011·16.17 MB·English

Diss. ETH No. 19194
Comparative Evaluation of
Three-Phase Si and SiC
AC-AC Converter Systems
A dissertation submitted to
ETH ZURICH
for the degree of
DOCTOR OF SCIENCES
presented by
THOMAS FRIEDLI
Dipl.-Ing., M.Sc. ETH Zurich
born 27th February 1979
citizen of Seeberg, Switzerland
accepted on the recommendation of
Prof. Dr. Johann W. Kolar, examiner
Prof. Dr. Robert D. Lorenz, co-examiner
2010

Abstract
In academia, for more than thirty years, Matrix Converters have been
considered as one of the future converter concepts for variable speed
drives for industry and more recently also for More Electric Aircraft or
renewable energy applications. However, despite intensive research for
the last decades, Matrix Converters have until now only achieved low
market penetration. In industry, the most widely used bidirectional,
low-voltage ac-ac converter topology is the two-level Voltage Source
Back-to-Back Converter.
The main objective of this PhD thesis is to derive and investigate the
key criteria required for a systematic comparative evaluation of ac-ac
converter systems. Based on a suggested set of criteria, a comprehensive
comparison of the Voltage Source Back-to-Back Converter, the Current
Source Back-to-Back Converter, the Indirect Matrix Converter, and the
Conventional (direct) Matrix Converter is performed for a 15kW per-
manent magnet synchronous motor drive.
The comparison involves the investigation of the required silicon chip
area for a defined maximum admissible thermal loading of the power
semiconductors, the passive components including the EMI input fil-
ter, the total losses and achievable efficiency, and a prediction of the
resulting converter volume. A particular focus is on the experimental
investigation and performance analysis of normally-on SiC JFET pro-
totype devices, which are close to commercialization.
With this comparativeevaluation, a systematic procedure is presented
that ultimately enables to identify advantageous application areas of the
considered converter topologies.

Kurzfassung
Seit nunmehr dreissig Jahren wird der Matrixumrichter in der akade-
mischen Gemeinschaft intensiv erforscht und als eine vielversprechende
Schaltungstopologie für zukünftige effiziente und kompakte Antriebs-
systeme für Industrie- und Luftfahrtanwendungen diskutiert. Trotz in-
tensiver Forschung konnte sich der Matrixumrichter in kommerziellen
Antriebssystemen bisher jedoch nicht etablieren. Der industriell am
weitesten verbreitete bidirektionale dreiphasige Umrichter für Nieder-
spannungsantriebe ist der Zweipunkt-Spannungszwischenkreisumrichter.
Das Hauptziel dieser Dissertation liegt im Eruieren und Herleiten
verschiedener Schlüsselkriterien und Vergleichsmethoden und dem an-
schliessenden Durchführen einer systematischen und ganzheitlichen Be-
wertung verschiedener dreiphasiger Umrichtersysteme. Basierend auf
den gefundenen Bewertungskriterien wird ein umfassender Vergleich
zwischen dem Spannungs- und Stromzwischenkreisumrichter, dem In-
direkten Matrixumrichter und dem Direkten Matrixumrichter zur Spei-
sung eines 15kW Antriebs mit einer Permanentmagnet-Sychnronma-
schine präsentiert. Der Vergleich umfasst die Bestimmung der benötigten
Chipfläche der Leistungshalbleiter für einen gegebenen Arbeitspunkt,
die Prädiktion der leitungsgebundenen elektromagnetischen Störaussen-
dung, die Modellierung der passiven Komponenten einschliesslich des
EMV Eingangsfilters,die Berechnung des erreichbaren Gesamtwirkungs-
grads und die Vorhersage des resultierenden Umrichtervolumens. Ein
besonderes Augenmerk wird dabei auf die Untersuchung von selbstlei-
tenden SiC JFET-Prototypenhalbleitern gelegt, welche kurz vor der
Markteinführung stehen und einer vergleichenden Bewertung mit Si
IGBTs neuster Generation. Verschiedene Hardwareprototypen wurden
implementiert, um das Betriebsverhalten der betrachteten Umrichter
experimentell zu untersuchen und die Modelle zu parametrieren und
viii Kurzfassung
zu verifizieren. Mit dieser Vergleichsstudie wird ein systematisches Ver-
fahren aufgezeigt, welches ermöglicht, die Anwendungsfelder der unter-
suchten Umrichterkonzepte zu bestimmen und analytischzu beschreiben.
Damit wird implizit die Basis für eine technisch-kommerzielle Bewer-
tung verschiedener Schaltungstopologienund Komponententechnologien
für Umrichtersysteme gelegt.
Acknowledgments
The first person I would like to express my sincere gratitude is Pro-
fessor Johann W. Kolar, Head of the Power Electronic Systems (PES)
Laboratory of ETH Zurich, for his wide ranging support, expertise, en-
couragement, and trusting belief in me throughout my PhD. He did not
only provide me with a challenging and incentive working environment,
but also enabled me to participate in various international conferences
and to broaden my mind and professional knowledge through interna-
tional industry research collaboration.
I also wish to express my appreciation to Professor Robert D. Lorenz
from the University of Wisconsin-Madison, USA, for kindly accepting
our invitation to take part in the PhD defense as a co-examiner and his
interest in this work.
Special thanks are due to Dr. Simon D. Round for his assistance
with reviewing publications and supervising my industry projects during
the first two years of my PhD, before he started his new job at ABB
Switzerland.
My keen appreciation goes to Dr. Peter Friedrichs from SiCED-Infi-
neon, Germany, for providing us with numerous silicon carbide JFET
prototype devices and his expertise in silicon carbide semiconductor
technology. Without these devices, the analysis and implementation of
silicon carbide power converters would not have been possible.
I am also indebted to Serge Bontemps from Microsemi, France, for
his valuable information and support in semiconductor and packaging
technology.
Sincere thanks are extended to Mario Schweizer for his elaborate re-
design and implementation of the control platform for the Ultra Sparse
Matrix Converter during his master thesis research.
x Acknowledgments
I also wish to thank my friends and colleagues both within and out-
side ETH Zurich, especially my present and former office mates Daniel
Aggeler, Mario Schweizer, John E. Pellegrini, André S. Franchiosi, Frank
Schafmeister, Marcelo L. Heldwein, and Guanghai Gong for their friend-
ship, support, and vital technical assistance throughout the different
stages of this work.
Many other characters, in particular from PES Laboratory, contri-
buted to my PhD research. Therefore, I would like to thank all people
who have given any technical, administrative, or educational help dur-
ing the course of my work, and therewith contributed to an agreeable
and efficient working environment. Special thanks go to the staff mem-
bers of the electronics laboratory, Peter Seitz, Hansueli Altorfer, and
Dominik Hassler, who have always been constructing and implementing
sophisticated, industry-oriented hardware prototypes, which I believe is
essential to perform what we call “state-of-the-art” research in Power
Electronics.
I also wish to express my appreciation to Peter Albrecht for steadily
maintaining our electronics equipment and for his efforts in finding dis-
tributors for our sometimes special electronic component requirements.
I am also indebted to all of our present and former administrative
staff members namely Roswitha Coccia, Monica Kohn, Anita Scherrer,
Priska Maurantonio, Gabriella Speck, Isabelle von Niederhäusern, and
Dr. Beat Seiler for coordinating my industry projects, organizing trips to
conferences, updating web pages, doing accounting and billing, filling in
customs forms, etc. for simply keeping the administrative system alive.
Last but not least, I gratefully record the parts played by our IT
systems administrators Claudia Stucki and Markus Berger who have
always been endeavored to keep our desktop PCs and simulation server
arrays safe and up-to-date and to solve our software problems.
Finally, but most importantly I would like to express my heartiest
thanks to my family for providing me with a stable, loving, and stimulat-
ing upbringing, and for supporting me in many different ways through-
out my life, my studies, and my PhD.