1、Motors andDrivesA Practical Technology GuideDave PolkaMD05-front.fm Page iii Tuesday, October 25, 2005 10:07 AMNoticeThe information presented in this publication is for the general education of the reader. Because neither the author nor the publisher have any control over the use of the information
2、 by the reader, both the author and the publisher disclaim any and all liability of any kind arising out of such use. The reader is expected to exercise sound professional judgment in using any of the information presented in a particular application.Additionally, neither the author nor the publishe
3、r have investigated or considered the affect of any patents on the ability of the reader to use any of the information in a particular application. The reader is responsible for reviewing any possible patents that may affect any particular use of the information presented.Any references to commercia
4、l products in the work are cited as examples only. Neither the author nor the publisher endorse any referenced commercial product. Any trademarks or tradenames referenced belong to the respective owner of the mark or name. Neither the author nor the publisher make any representation regarding the av
5、ailability of any referenced commercial product at any time. The manufacturers instructions on use of any commercial product must be followed at all times, even if in conflict with the information in this publication.Copyright 2003 ISAAll rights reserved. Printed in the United States of America. 10
6、9 8 7 6 5 4 3 ISBN 1-55617-800-XNo part of this work may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of the publisher.ISA67 Alexander DriveP.O. Box 12277Res
7、earch Triangle Park, NC 27709Library of Congress Cataloging-in-Publication DataPolka, David. Motors & drives / by David Polka. p. cm. Includes bibliographical references and index. ISBN 1-55617-800-X 1. Electric motors. 2. Electric driving. I. Title:Motors and drives. II. Title. TK2514 .P65 2002 621
8、.46-dc21 2002012843MD05-front.fm Page iv Tuesday, October 25, 2005 10:07 AMMotors and DrivesA Practical Technology GuideMotors&Drives.book Page i Monday, January 10, 2005 1:54 PMMotors&Drives.book Page ii Monday, January 10, 2005 1:54 PMDedicationThis book is dedicated to my wife, Candy, and my daug
9、hter, Korey. Their support, understanding and encouragement has been monu-mental in the creation of this literary work. (Maybe Ill get more projects done around the house, now that my work is complete.)I also dedicate this book to my parents, Chet and Carol, who taught me to stick to my goals, and t
10、hat you cant put a price-tag on the value of education. Teachers are essential to the creation of a well-trained and efficient functioning society. Motors&Drives.book Page v Monday, January 10, 2005 1:54 PMMotors&Drives.book Page vi Monday, January 10, 2005 1:54 PMContents viiContentsAbout the Autho
11、r. ixAcknowledgments . xiIntroduction xiiiChapter 1: What is a Drive? 1Drive Principles of Operation.5Types of Drives, Features and Principles7Chapter Review .14Check Your Knowledge .14Chapter 2: Review of Basic Principles 15Introduction.15Electrical Principles 15Electrical/Electronic Devices 29Mech
12、anical Principles 41Mechanical Devices58Chapter Review .65Check Your Knowledge .67Chapter 3: AC and DC Motors69Introduction.69DC Motors: General Principles of Operation69AC Motors: General Principles of Operation90Servomotors: General Principles of Operation.122Chapter Review .127Check Your Knowledg
13、e .129Chapter 4: AC and DC Drives .131Introduction.131DC Drives .131AC Drives .156Chapter Review .201Check Your Knowledge .203Motors&Drives.book Page vii Monday, January 10, 2005 1:54 PMviii Motors and DrivesChapter 5: Drive Control and Feedback Devices 205Open-Loop Control 205Closed-Loop Control 20
14、6Drive Control Methods: DC . 216Drive Control Methods: AC . 219Sensors and Controls . 226Chapter Review . 228Check Your Knowledge . 229Chapter 6: Drive System Control Methods 231Introduction. 231Coordinated Drive Systems 231DC Systems 246AC Systems 251AC versus DC Drive Systems . 257Chapter Review .
15、 261Check Your Knowledge . 261Chapter 7: Maintenance and Troubleshooting of Drive Systems. 263Routine Drive Maintenance 263General Troubleshooting . 269Chapter Review . 270Check Your Knowledge . 271Chapter 8: Final Review & Closing Remarks. 273What is a Drive? Why Drives are Applied . 273Review of B
16、asic Principles . 273Motors 275Drives. 276Drive Control and Feedback Devices . 278Drive Systems 279Maintenance and Troubleshooting of Drive Systems 280Closing Remarks 280Chapter 9: Check Your Knowledge.283Appendix A: Check Your Knowledge - Answers . 287Appendix B: Formulas and Conversions 301Appendi
17、x C: Drive Enclosure Types . 311Appendix D: Terms and Definitions. 315Bibliography 355Index 359Motors&Drives.book Page viii Monday, January 10, 2005 1:54 PMAbout the AuthorDave Polka has devoted his professional career to training and educa-tion, in the areas of Electronics and Motor Speed Control.
18、He gradu-ated from the University of Wisconsin Stout, Menomonie, WI, with a Bachelor of Science Degree in Industrial Education, and an empha-sis in Electronics and Controls.His first position was with Homestead High School, Mequon, WI, where he spent eight years as an Industrial Education teacher. H
19、is programs included: Basic Electricity and Electronics, Advanced Elec-tronics and Instrumentation, and Broadcast Radio. He held several positions at Allen-Bradleys Drives Division, Mequon, WI. He spent three years as a Technical Writer of operation and maintenance manuals, and seven years as Instru
20、ctor and Supervisor of Drives Training, encompassing sales, service and customer training.Mr. Polka has published several trade journal and website articles, dealing with topics such as: “What is a Drive?” “How to Maintain a VFD” and “Energy Savings with VFDs in Paint Spray Booths.”He currently hold
21、s the Training Center Manager position for ABB Inc, Drives & Power Electronics, in New Berlin, WI. For the past eight years, he has conducted distributor and customer classes on drive - applications, programming and operation, for ABB University.Motors&Drives.book Page ix Monday, January 10, 2005 1:
22、54 PMMotors&Drives.book Page x Monday, January 10, 2005 1:54 PMAcknowledgments xiAcknowledgmentsThere are many people that had a hand in the success of this project. It could not have been created by one person working in a vacuum. I would like to thank the following people for their assistance in m
23、aking this book, what it is.I would be remiss in mentioning the people that inspired me throughout the years to do my best, research until I find answers, and persist in the pursuit of excellence. I began my knowledge base, through the direction and guidance given by those at Allen-Bradley, now Rock
24、well Automation. I especially appreciated the assistance by the late Jim Bonham. His insight into the world of AC and DC drives gave me a foundation from which to grow. I also thank Howard Murphy, Dave Caruana, Scott Patterson, Clar-ence Phipps, Jerry Muehlbauer and Glenn Reinders, for their assista
25、nce throughout my formative years.I also want to thank Ken Graber of Zigman Joseph Stephenson, for his guidance and encouraging me to accept the challenge of writing technical articles, and ultimately, the writing of this book. Ken has injected a shot of “reality” into a rather hectic writing schedu
26、le, both professionally and per-sonally. I want to thank my professional colleagues at ABB Inc. First and foremost, Chuck Clark, for his approval of the use of various written works, as well as photos and graphics. I also thank Roy Coleman and Joe Maloni for allowing me time to pursue my publishing
27、goals. I also acknowledge the following individuals for their proofreading and technical suggestions: Becky Nethery, Mark Kenyon, John Sutschek, Randy Stevens, Dennis Miller, Michael Tews, Jim Nash, Tim Gladd, and Stuart Koym. I thank Jamieson Greig, for his insight into legal aspects of literature.
28、Mike Olson, has been my mentor, and very instrumental in the comple-tion of this literary work. I appreciated his encouragement, proofreading and technical expertise. An accomplished author himself, Mike has always made time for my last minute questions and offered constructive criticism that ultima
29、tely made my written documents more understand-able and technically accurate.I also thank Bill Wagner for his scanning, creation and digital photography techniques, as well as Randy Stevens, for his photo art rework and graph-Motors&Drives.book Page xi Monday, January 10, 2005 1:54 PMxii Motors and
30、Drivesics assistance. I thank those affiliated with ABB, directly or indirectly, including: Chuck Cowie, Todd Vigorito and Walt Dembiczak for their insight, suggestions and comments on previously written material. The people at ISA have been most helpful in guiding me through the maze of writing req
31、uirements. I especially thank Matt Lamoreaux for his encouragement, and Shandra Botts for her schedule keeping. I also thank Joice Blackson, for her assistance in the early stages of this project.Motors&Drives.book Page xii Monday, January 10, 2005 1:54 PMIntroduction xiiiIntroductionTo some, motor
32、speed control is somewhat of a mystical science, a science that causes motors and machines to sometimes operate in unexpected ways. Over 30 years ago, AC drives were considered “new technology.” If a company wanted to have reliable production, it should stick with known, proven technology that of DC
33、 drives and motors. In many cases, the cost of transferring manufacturing machinery to AC technology, would not warrant the lengthy paybacks. It seemed that AC technology had a long way to go, to improve in reliability and reduced cost. In some technicians minds, you would need to have a new, back-u
34、p AC drive, because the first one would probably fail upon start-up.As time marched on, low horsepower AC technology improved to the point where total installed costs, including the motor, were equal to or even less expensive than the DC alternative. The size of the AC drive was equal to or smaller
35、that its DC counterpart. Improvements in power elec-tronics increased the reliability of AC drives, to the point where one would almost never hear of a drive failure upon start-up.This book is intended to de-mystify drive and motor technology, used in todays modern manufacturing processes. The text
36、has roots in the practi-cal side of drive and motor use, with the “design engineering” side of tech-nology, presented in commonly used terms. An attempt is made to help the reader “start from scratch,” gathering and reviewing a collection of basic information from basic electrical principles to DC a
37、nd AC motor principles of operation. The initial cost of a motor only represents about 3% of its total lifetime expense, with operating costs representing the other 97%. Therefore, energy savings with VFDs (variable frequency drives) is a topic that faces many consumers in this day of rising energy
38、costs.From the basics, the reader is lead on a historical path reviewing DC and AC drives that are 10 years old or more. The focus of this section however, points to the new and improved technology, in both types of drives. Motors&Drives.book Page xiii Monday, January 10, 2005 1:54 PMxiv Motors and
39、DrivesFrom that point, the reader is lead into feedback methods and devices, and into closed loop control of drive systems. The concepts reviewed, are the basics of modern industrial and commercial HVAC systems.An overall attempt is made to start with the basics, and move into the more complex conce
40、pts of drive operation and design. The book also com-pares the two technologies, AC and DC, and provides questions and issues to review when making any drive technology decision. The book ends with general principles of drive troubleshooting, and ideas on how to con-duct routine drive maintenance.Su
41、mmary sections and “Test your Knowledge” questions are provided at the end of each chapter, to assist in confirming important points. In addi-tion, the Appendices are offered as a reference section, providing terms and definitions, as well as formulas, conversions and enclosure informa-tion.Many typ
42、es of drives are on the market today ranging from the size of a persons fist to 14 bay cabinets, with the electronics to power thousands of motor horsepower. Open loop (V/Hz) AC drives are the most common drive in use today, with up to 70% use, according to some surveys. Behind the standard open loo
43、p drive, stands several other types of drive products: brush DC servo drives, DC drives, SCR DC drives, stepper drives / motors, AC servo drives, and brushless DC servo drives. Though in smaller percentage of use, encoderless flux vector, closed loop vector, and direct torque control type drives are
44、 gaining in popularity.It is hoped that this book can be used as a resource for those that design, apply or maintain AC or DC motor speed controls. It is meant to be an overall “book of knowledge” on a students, technicians or engineers bookshelf.Motors&Drives.book Page xiv Monday, January 10, 2005
45、1:54 PMChapter 1: What is a Drive? 1What is a Drive?In the most generic sense, a drive is a device that controls speed, torque, direction, and the resulting horsepower of a system. There are many dif-ferent types of drives, and they will be discussed later in this chapter. For now, we will focus on
46、the reasons for drive use in our industrial and com-mercial environments. To appreciate the use and benefits of any type of drive, we need to look at a generic application and determine how the sys-tem could be improved.Figure 1-1 shows a prime candidate for a variable-speed drivea con-veyor in a ma
47、nufacturing plant.In Figure 1-1, we can see that the conveyors main intent is to move prod-ucts from production to the warehouse. A typical way to move products is by means of a motor. The generic motor on this conveyor operates at only one speed. With only one speed of motion, this type of manufact
48、uring sys-tem has its drawbacks.Figure 1-1. Generic conveyor systemProduction WarehouseFixed SpeedMotorMotors&Drives.book Page 1 Monday, January 10, 2005 1:54 PM2 Motors and DrivesThe products can reach the warehouse only in a given timeframe. There is no way to gradually increase the conveyor speed
49、. If it takes the motor a very short time to accelerate, the boxes may fall off the conveyor because of the accelerating forces. We will look at several factors that lead to the use of a variable-speed drive: efficiency gains, process changes and improvements, and system coordination.Efficiency Gains We may view the system in Figure 1-1 as very inefficient. We are locked into whatever efficiencies the motor can provide, given a somewhat vari-able amount of loading. If the motor in Figure 1-1 happened to be an alternating
