MAGNETIC COMPONENTS FOR POWER ELECTRONICS

Transcription

1 MAGNETIC COMPONENTS FOR POWER ELECTRONICS

2 MAGNETIC COMPONENTS FOR POWER ELECTRONICS by Alex Goldman Ferrite Technology Worldwide, US.A. SPRINGER SCIENCE+BUSINESS MEDIA, LLC

3 ISBN ISBN (ebook) DOI / Library of Congress Cataloging-in-Publication Data A c.i.p. Catalogue record for this book is available from the Library of Congress. Copyright 2002 by Springer Science+Business Media New York Originally published by Kluwer Academic Publishers in 2002 Softcover reprint ofthe hardcover lst edition 2002 AII rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, mechanical, photocopying, record ing, or otherwise, without the prior written permission of the publisher, Springer Science+Business Media, LLC. Printed on acid-free paper.

4 TABLE OF CONTENTS Preface Acknowledgements xi xiii Chapter I-Applications and Topologies for Power Electronic Systems 1 Introduction-History of Power Electronics Applications for Power Electronics Power Converters Basic Topologies for Power Converters Practical Converter Topologies Flyback Converter Forward Converter Push Pull Converter Converter Strengths and Weaknesses The Hysteresis Loop for Power Materials Switching Power Supplies Ferroresonant Converters Soft Switching in Common Topologies 19 Summary 20 Chapter 2- Main Considerations for Magnetic Component Choice 25 Introduction Considerations Based on Component Function Magnetic Component Choices Components for Power Transformers Ferrite Power Transformers Frequency-Voltage Considerations Frequency-Loss Considerations Choosing the Best Ferrite Power Transformer Material Power Ferrite Core Shapes Component Processing after Assembly High Frequency Applications Metal Strip Power Transformers Amorphous Metal Strip Cores Nanocrystalline-Based Power Transformers Cost Considerations for Magnetic Components Competitive High Frequency Power Materials Design Considerations in Component Choice Ferrites Versus Metallic Magnetic Materials Output Power Inductors Ferrite Versus Metallic Power Inductors Power Factor Correction Cores 46

5 vi MAGNETIC COMPONENTS FOR POWER ELECTRONICS Magnetic Amplifier Cores Pulse Transformers Components for EMI Suppression Materials for EMI suppression Amorphous and Nanocrystalline Materials for EMISuppression Common-Mode Filters 51 Summary 53 Chapter 3- Magnetic Materials for Power Electronics 55 Introduction Soft Ferrites for Power Electronics Ferrite Material Permeabilities Initial Permeabilities Amplitude Permeability Maximum Permeability Permeability-Temperature Dependence Complex Permeability Saturation Induction for Ferrite Materials I-Temperature Dependence of Saturation Core Losses Output Power Considerations-Performance Factor Curie Temperature Resistivity Density Remanence and Squareness Coercive Force Ferrite Power Inductor Materials Magnetic Properties-Ferrite Common-Mode Materials l2- Magnetic Properties of Ferrite EMI Materials Frequency Characteristics of EM I Materials Magnetic Properties of Metallic Strip Materials Permeabilities-Metallic Magnetic Strip Materials Amorphous Metal Magnetic Materials I-Advantages of Amorphous Magnetic Metals Disadvantages ofiron-based Amorphous Alloys Processing of Amorphous Metals Amorphous Metals- High Perm-High Frequency Nanocrystalline Materials Nanocrystalline Materials-High Frequency Power Amorphous-Nanocrystalline Materials for EMI Powder Core Materials-Output Chokes, EMI and PFC Iron Powder Cores NiFe Powder Core Materials Sen dust Powder Material 100

6 TABLE OF CONTENTS vii Chapter 4- Core Shapes for Power Electronics 105 Introduction Ferrite Core Shapes Pot Cores Doube-Slab Cores l.3- RM Cores and PM Cores ECores E-C Cores ETD Cores E-RCores III EP Cores III PQ Cores Toroids EFD Cores Effective Core Properties of Power Core Shapes Measurement of Effective Permeability Inductance Factor, AL Gapped Cores Pre-polarized Cores Low Profile Ferrite Power Cores Surface-Mount Design in Power Ferrites Planar Technology Integrated Magnetics Core Shapes for Metal Strip Materials Core Shapes for Metal Powder Components 125 S ~ m ~ 1 ~ Chapter 5- Core Sizes-Design Considerations in Power Electronics 127 Introduction Determining the Size of the Transformer Core Initial Considerations -Designing Transformer Core Other Area Product Relationships Voltage Regulation in Transformers Other Transformer Design Techniques Winding Loss-Limited Design Regulated Limited Design Saturation Limited Design Core Loss-Limited Design Power ferrite Limited Design from Vendors' Catalogs Philips(Yageo) Epcos (Siemens) A VX (Thomson) TDK Ferrite Component Design-Power Transformers Creepage Allowance Effect of Core Size-Dimensional Resonance 144

7 viii MAGNETIC COMPONENTS FOR POWER ELECTRONICS 5.2-Thennal Characterization-Power Ferrite Cores Winding Losses Completing Transformer Design-Winding Data Very High Frequency Power Ferrite Operation Ferroresonant Transformers Design of Power Inductors Design of an Inductor for a Switching Regulator McLyman Treatment ofinductor Design Flyback Converter Design Swinging Choke Magnetic Amplifier-Multi-Output Design 161 Appendix 5.1- Design Example-McLyman Kg Approach 161 Appendix 5.2- Magnetics Inductor Design Method-Hanna Curves 164 Appendix 5.3- Magnetics Inductor Design for Switching Regulators 165 Appendix 5.4- McLyman Design-Switching Inductor- Kg Approach 168 Appendix 5.5- Output Inductor Design-Metglas R Amorphous Core 171 Appendix 5.6- Output Inductor-LPT E2000Q Nanocrystalline Core 173 Chapter 6-Commercially-Available Components for Power Electronics 181 Introduction TDK Ferrite Power Electronics components TDK Power Ferrite Materials Philips (Yageo) Power Ferrite Components Epcos (Siemens) Power Ferrite Components Magnetics Power Ferrite Components Tokin Power Ferrite Components Fair-Rite Power Electronic Components Ferronics Power Ferrite Components FDK Power Ferrite Components AVX (Thomson) Power Ferrite Components MMG (Neosid) Power Ferrite Materials Kaschke Power Ferrite Materials Vogt Power Ferrite Materials Samwha Power Ferrite Materials Steward Power Ferrite Materials Ferrite International (TSC) Power Ferrite Materials Ceramic Magnetics Power Ferrite Materials Tomita Power Ferrite Materials Iskra Power Ferrite Materials Domen Power Ferrite Materials Hitachi power Ferrite Materials Cosmo Power Ferrite Materials Acme Power Ferrite Materials Hinoday Power Ferrite Materials Isu Power Ferrite Materials Mianyang Power ferrite Materials Hebei Power Ferrite Materials 198 Appendix 6. I-Listing of Catalog Data for Ferrite Suppliers 198

8 TABLE OF CONTENTS ix Magnetics Metallic Magnetic Strio Materials Arnold Metallic Magnetic Strip Materials Honeywell (Metglas) Amorphous Metal Materials Vacuumschmelze Amorphous and Nanocrystalline Alloys Toshiba Amorphous Alloys TDK Amorphous Metal Cores CoreMaster Amorphous and Nanocrystaline Cores Magnetec Nanocrystalline Cores Magnetics Powder Core Materials Arnold Engineering Powder Core Materials Micrometals Powdered Iron Cores Pyroferric Powdered Iron Cores 230 Appendix 6.2-Listing of Catalog Data for Suppliers of Metallic Strip and Powder Cores 230 Summary 250 Chapter 7- Design Aids in Magnetic Component Choice for Power Electronics 251 Introduction Books on Power Electronics Power Electronics Magazines Power Electronics Organizations Power electronics Web Sites Power Electronics Conferences Power Electronics at Universities and Research Labs Power Electronics Web Tutorials Power Electronics Software Power Electronics Short Courses Component Vendors' CDROM and Diskettes Internet Web Sites Magnetic Component Standards 256 Appendix 7. I-Recent Power Electronic on Specific Power Electronic Subjects 257 Appendix 7.2-IEC and ASTM Standards 260 Bibliography 265 Appendix I-Abbreviations and Symbols 269 Appendix 2-Addresses of Major Suppliers Power Electronic Components 275 Appendix 3-Units Conversion from CGS to MKS Systems 283 Index 285

9 Preface Power electronics is a rapidly-growing technology encompassing a large variety of applications including automotive, telecommunications, computers and alternative-energy systems. While the origin of modem power electronics was stimulated by the development of power semiconductor devices for high frequency switching purposes, other important and necessary accompanying component have been magnetic cores for transformers and inductors. This need has been especially true for the square wave features produced by solid-state switches that yield a plethora of higher harmonics. The heart of the new circuitry was the switched mode power supply (SMPS). As this new technology developed, there was an increased demand for miniaturization. Magnetic cores were traditionally the largest component in a solidstate circuit. Operation at higher frequencies was seen as a possible solution, As power semiconductors were designed for higher frequencies, the magnetic component suppliers were able to develop new materials and shapes that were optimized for the new conditions. Ferrites were found to be the most suitable materials for the low to medium wattage power supplies. In my fltst book, Modem Ferrite Technology, I said that "ferrites were the new kids on the block". While ferrites still maintain their dominance as power magnetic materials, "there are newer kids on the block ", namely amorphous and nanocrystalline materials. Although these materials are still in their infancy, they require more than a glancing look. My purpose in writing this book was to review the many changes that have taken place in the past 5-10 years in power magnetic components. Some ofthese changes are; 1. Changes in the management of several of the major magnetic component suppliers. These suppliers included Siemens, Philips, Thomson and Allied- Signal (Metglas ). 2. Changes in the available power magnetic materials to operate at higher frequencies and higher DC bias. 3. Greater use of low-profile and planar core shapes 4. The use of Power Function Correction (PFC), Resonant Converter and Soft-Switching Circuits 5. Greater emphasis on EMI requirements in Power electronic cir cuits. 6. The development of cores using amorphous and nanocrystalline materials. This book will discuss these changes and show how it affects power electronic component choice.

10 xii MAGNETIC COMPONENTS FOR POWER ELECTRONICS The main intent of this book is to advise power electronic design engineers and other magnetic component users as to the considerations that should be made in the choice of an optimum magnetic component for a particular application. This book was not intended to be a manual for the complete circuit design of a power electronic system. There are many other fine books that deal with this subject and some of the are listed in this book under the topic of design aids. Also missing from this book are the sections on basic magnetic theory and the physical, chemical and manufacturing aspects of ferrites. These are found in the author's book, Handbook of Modem Ferromagnetic Materials. There is, however, material-oriented information on the new amorphous and nanocrystalline materials since power components of these materials were not covered elsewhere. Aside from these new materials and ferrites, other metal strip materials and metal powder cores are also discussed. Suppliers of magnetic components may find this book useful as a guide to what properties are desired by the device or system engineer. The frrst chapter deals with the various power electronic topologies including those involved with switched mode power supplies and resonant converters. The second chapter list the considerations encountered in the choice of a magnetic component including the material and shape. The third chapter expands on the material properties while the fourth chapter is involved with component shape including low-profile, planar cores and integrated magnetics. Chapter 5 is involved with the final choice of the size of the core and the windings needed. Included are some examples including the steps in determining the optimum size. These examples include applications for ferrites, amorphous cores and nanocrystalline cores. The sixth chapter contains a compendium of catalog data from the major magnetic component manufacturers in the World. While the data for each individual core are not included (the book would be voluminous), the material parameters and core shapes available are included. The final chapter includes aids for magnetic component design including books, articles, manufacturers CD-ROM's or diskettes and Web sites. Appendices include Tables of Units Conversion, Symbols, IEC and ASTM Standards and Addresses of Major Magnetic Component Suppliers. Alex Goldman

11 ACKNOWLEDGEMENTS I would like to thank Professor Robert W. Erickson for permission to use some material from his recent book, Fundamentals of Power Electronics, 2 nd Edition. I would also like to thank Gordon "Ed" Bloom for permission to use some figures from his book, Modern DC-To-DC Switchmode Power Converter Circuits" and for discussions about this book. Thanks also are due to Colonel Wm. McLyman, a friend of many years for his useful design notes. Joe Huth III provided some photos of ferrite cores. I could not have written this book without the loving understanding of my wife, Adele, and the encouragement of my children, Mark, Beth and Karen.