Analysis and Design of Multicell DC/DC Converters Using Vectorized Models E-Book

Thierry Meynard

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 114

Veröffentlichungsjahr: 2015

Beschreibung

Shows how the concepts of vectorization and design masks can be used to help the designer in comparing different designs and making the right choices. The book addresses series and parallel multicell conversion directly, and the concepts can be generalized to describe other topologies.

Leseprobe

Contents

1 General Properties of Multilevel Converters

1.1. Time-domain: multilevel waveform and apparent switching frequency

1.2. Frequency domain: harmonic cancellation

1.3. Transient response

1.4. Conclusion

2 Topologies of Multilevel DC/DC Converters

2.1. Series connection

2.2. Parallel connection

2.3. Series-parallel connection

3 Concept of Vectorization in PLECS

3.1. Vectorized components

3.2. Star-connection block and parallel multicell converter

3.3. Series connection block and series multicell converter

3.4. Generalized multicell commutation cell

3.5. Practice

4 Vectorized Modulator for Multilevel Choppers

4.1. General principle

4.2. xZOH: equalizing multisampler for multilevel choppers

5 Voltage Balance in Series Multilevel Converters

5.1. Basic principles

5.2. Linear circuits

5.3. Nonlinear variants

5.4. Loss-based design

5.5. Vectorized models of balance boosters

6 Filter Design

6.1. Requirements

6.2. Design process

7 Design of Magnetic Components for Multilevel Choppers

7.1. Requirements and problem formulation

7.2. Area product

7.3. Optimal area product of magnetic components for interleaved converters

7.4. Weight-optimal dimensions for a given area product

7.5. Volume-optimal dimensions for a given area product

7.6. Number of turns and air gap

7.7. Accounting for current overload

7.8. Optimal phase sequence for InterCell Transformers

7.9. Vectorized reluctance model of magnetics

7.10. Design process

8 Closed-Loop Control of Multilevel DC/DC Converters

8.1. Principle

8.2. Corresponding PLECS block

8.3. Average model of the macro-commutation cell for transient studies

8.4. Conclusion

Bibliography

Index

First published 2015 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc.

Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the undermentioned address:

ISTE Ltd27-37 St George’s RoadLondon SW19 4EUUK

www.iste.co.uk

John Wiley & Sons, Inc.111 River StreetHoboken, NJ 07030USA

www.wiley.com

© ISTE Ltd 2015The rights of Thierry Meynard to be identified as the author of this work have been asserted by him in accordance with the Copyright, Designs and Patents Act 1988.

Library of Congress Control Number: 2014956808

British Library Cataloguing-in-Publication DataA CIP record for this book is available from the British LibraryISSN 2051-2481 (Print)ISSN 2051-249X (Online)ISBN 978-1-84821-800-0

1

General Properties of Multilevel Converters

Multilevel converters use many different topologies depending on the type of conversion, the power range, etc., but the basic properties are always the same. These properties are reviewed here.

1.1. Time-domain: multilevel waveform and apparent switching frequency

Standard two-level converters use the variation of the duty cycle of these levels to regulate the average power flowing between a current source and a voltage source, which is generally referred to as pulse width modulation (PWM). Multicell converters combine such two-level waveforms to create multilevel waveforms. This is illustrated in with three of these two-level PWM waveforms of the same duty cycle and frequency but with a phase-shift of 120°. When the duty cycle is less than 1/3, the sum of the three is also a square voltage taking values 0 and 1. But when the duty cycle increases, the overlapping creates higher levels as shown in case of a duty cycle of 50% (right). In practice, since each cell handles a fraction of the power, the composition of PWM results generally in an average rather than a sum, and the amplitude is then times smaller. This property gave the name of multilevel converters that is in general used only for series connection and medium-voltage (MV) applications, although the same combinations of waveforms can be found on the current waveforms of parallel multicell converters used in low and very low-voltage (LV) applications.