Cover
Title Page
About the Authors
Preface
About the Book
1 Introduction
1. 1.1 The Energy‐saving Status of an Electric Motor System
2. 1.2 Main Development Ways of Energy Saving for Electric Motor System
3. 1.3 Energy Saving: The Basic National Policy of China
4. 1.4 Main Contents of This Book
2 Overview of Three‐Phase Asynchronous Motors
1. 2.1 Basic Structure and Characteristics of Three‐Phase Asynchronous Motors
2. 2.2 The Principle of a Three‐Phase Asynchronous Motor
3. 2.3 Working Characteristic of Three‐Phase Asynchronous Motors
4. 2.4 Mechanical Characteristics of Three‐Phase Asynchronous Motors
5. 2.5 Start‐up of Three‐Phase Asynchronous Motors
6. 2.6 Energy Efficiency Standards of Three‐Phase Asynchronous Motors
7. 2.7 Mainstream Products of Three‐Phase Asynchronous Motors
8. 2.8 Main Subseries Three‐Phase Asynchronous Motors in China
9. 2.9 Discussion Topics in the Chapter
3 Economic Operation of the Three‐Phase Induction Motor
1. 3.1 Loss Analysis of the Three‐Phase Induction Motor
2. 3.2 Efficiency and Power Factor of the Three‐Phase Asynchronous Motor
3. 3.3 Economic Operation of the Three‐Phase Induction Motor
4. 3.4 Calculation Methods for Energy Saving of the Three‐Phase Induction Motor
5. 3.5 Comparison and Evaluation Method of Motor Energy‐saving Effect
6. 3.6 Discussion Topics of the Chapter
4 The Energy‐saving Principle and Method of the Motor Power and Load Match
1. 4.1 Discussion on the “Lighter Load”
2. 4.2 Energy‐saving Principle of Power Matching
3. 4.3 Double Power Induction Motors and Energy‐saving Principle
4. 4.4 The Energy‐saving Method of the Y‐△ Conversion
5. 4.5 The Energy‐saving Method of Extended △ Winding Switching
6. 4.6 Discussion Topics in the Chapter
5 Energy‐saving Principle and Methods of Speed Matching
1. 5.1 Energy‐saving Principle of Speed Matching
2. 5.2 Energy‐saving Theoretical Analysis of Pump Speed Control
3. 5.3 Control Principle of Constant Pressure Water Supply System
4. 5.4 Application of Variable Frequency Speed Control Energy‐saving Technology
5. 5.5 Principles of Motor’s Pole Changing Speed Control
6. 5.6 Energy‐saving Principles and Applications of Combined Pole Changing Speed Control
7. 5.7 Discussion Topics in the Chapter
6 Energy‐saving Principle and Method of the Mechanical Properties Fit
1. 6.1 Load Characteristics of A Beam‐Pumping Unit
2. 6.2 Energy‐saving Principle of Mechanical Properties Fit
3. 6.3 Energy‐saving Instances of Mechanical Properties Fit
4. 6.4 Discussion Topics in the Chapter
7 The Energy‐saving Principle of Induction Motor Reactive Power Compensation
1. 7.1 Energy‐saving Principle of Induction Motor Reactive Power Compensation
2. 7.2 Capacity Selection for the Compensating Capacitor
3. 7.3 Static Reactive Power Compensation of Induction Motor
4. 7.4 Reactive Power Dynamic Compensation of the Induction Motor
5. 7.5 Hybrid Compensation
6. 7.6 The Discussion Topic of the Chapter
Further Reading
Index
End User License Agreement

List of Tables

Chapter 02
1. Table 2.1 Nameplate of three‐phase asynchronous motors.
2. Table 2.2 IE‐efficiency class.
3. Table 2.3 IE1 standard efficiency stipulated limits (50 Hz) (%).
4. Table 2.4 IE2 high‐efficiency stipulated limit (50 Hz) (%).
5. Table 2.5 IE3 ultra high‐efficiency stipulated limits (50 Hz) (%).
6. Table 2.6 Interpolation coefficients.
7. Table 2.7 American motors (EPACT) efficiency value (%).
8. Table 2.8 EU motors (CEMEP) efficiency value (%).
9. Table 2.9 Efficiency standards for three‐phase asynchronous motors in China (%).
10. Table 2.10 Main technical parameters and features of Y, Y2, and Y3 series.
11. Table 2.11 The efficiency of Y, Y2, and YX3 series three‐phase asynchronous motors.
12. Table 2.12 Technical data of Y2 series 2‐pole three‐phase asynchronous motors.
13. Table 2.13 Technical data of Y2 series 4‐pole three‐phase asynchronous motors.
14. Table 2.14 Technical data of Y2 series 6‐pole three‐phase asynchronous motors.
15. Table 2.15 Technical data of Y2 series 8‐pole three‐phase asynchronous motors.
16. Table 2.16 Categories, characteristics, and applications of main series products deriving from three‐phase asynchronous motors.
Chapter 03
1. Table 3.1 Comprehensive loss and comprehensive efficiency under various load rate.
Chapter 04
1. Table 4.1 All kinds of loss of two electric motors (kW).
2. Table 4.2 Y315M‐8/75kW the change of motor various losses (kW).
3. Table 4.3 The test parameters of the Y200L‐6/22kW motor.
4. Table 4.4 Efficiency and power factor of two kinds of motors.
5. Table 4.5 Input active power, reactive power, the power factor, and efficiency of the ∆ connection motor.
6. Table 4.6 Input active power, reactive power, the power factor, and efficiency of the Y connection motor.
Chapter 05
1. Table 5.1 Comparison of performance, efficiency, cost, and reliability of all kinds of speed control mode.
2. Table 5.2 Comparison table of power consumption.
Chapter 07
1. Table 7.1 The test data of the motor (18.5 kW/4 pole).
2. Table 7.2 The test data of a motor with a compensation capacitor (18.5 kW/4 pole).

List of Illustrations

Chapter 02
1. Figure 2.1 Configuration of squirrel cage three‐phase asynchronous motor. 1, bearing; 2, front end cover; 3, shaft; 4, terminal box; 5, ring; 6, stator core; 7, rotor; 8, stator winding; 9, frame; 10, back end cover; 11, fan housing; 12, fan.
2. Figure 2.2 (a) Stator core and (b) stator slot types.
3. Figure 2.3 The squirrel cage rotor. (a) Cast‐aluminum rotor winding and (b) copper‐cage rotor winding.
4. Figure 2.4 Three‐dimensional sectional drawing of a squirrel cage three‐phase asynchronous machine.
5. Figure 2.5 Explanation of motor type on the nameplate.
6. Figure 2.6 The principle of three‐phase asynchronous motors. (a) Stator winding space diagram, (b) connection diagram of three‐phase stator windings, and (c) three‐phase symmetrical currents.
7. Figure 2.7 Generation of a rotating circular magnetic field in motor. (a) ωt = 0°, i_U = I_m, i_V = i_W = −I_m; (b) ωt = 120°, i_V = I_m, i_W = i_U = −I_m; (c) ωt = 240°, i_W = I_m, i_U = i_V = −I_m; and (d) ωt = 360°, i_U = I_m, i_V = i_W = −I_m.
8. Figure 2.8 Generation of motor’s rotating field with two pairs of poles. (a) ωt = 0°, (b) ωt = 120°, (c) ωt = 240°, and (d) ωt = 360°.
9. Figure 2.9 Working principle schematic diagram of asynchronous motors.
10. Figure 2.10 T equivalent circuit of asynchronous motors.
11. Figure 2.11 (a) No‐load equivalent circuit of asynchronous motors and (b) starting or locked‐rotor equivalent circuit of asynchronous motors.
12. Figure 2.12 Γ equivalent circuit of asynchronous motors.
13. Figure 2.13 Schematic diagram of equivalent circuit’s loss of asynchronous motors.
14. Figure 2.14 Power flowing diagram of asynchronous motors.
15. Figure 2.15 Working characteristic of asynchronous motor.
16. Figure 2.16 Mechanical characteristic of three‐phase asynchronous motors.
17. Figure 2.17 Three‐phase asynchronous motors’ artificial characteristic of reducing voltage.
18. Figure 2.18 Artificial characteristic of connecting symmetrical three‐phase resistances in rotor’s loop.
19. Figure 2.19 Artificial characteristic of variable frequency speed control.
Chapter 03
1. Figure 3.1 The efficiency and power factor curve of Y2‐250M‐4 motor.
2. Figure 3.2 The relationship between the motor efficiency and economic operation.
3. Figure 3.3 The comprehensive efficiency of Y2‐250M‐4.
Chapter 04
1. Figure 4.1 Y280S‐6 efficiency and power factor curves.
2. Figure 4.2 Y100L‐4 efficiency and power factor curves.
3. Figure 4.3 The efficiency curve of two kinds of motors.
4. Figure 4.4 The power factor curve of two kinds of motors.
5. Figure 4.5 The principle of control system of the series dual‐power winding motor.
6. Figure 4.6 The input power curve in the motor windings of ∆ connection and Y connection.
7. Figure 4.7 The principle of control system of the motor winding in Y‐∆ connection.
8. Figure 4.8 The connection principle figure of the extended ∆. (a) ∆ connection and (b) extended ∆ connection.
9. Figure 4.9 The principle of control system of the extended ∆ winding switching.
Chapter 05
1. Figure 5.1 Mechanical characteristic curve of pump.
2. Figure 5.2 A diagram of building water supply system. 1, Motor; 2, pump; 3, check valve.
3. Figure 5.3 Structure diagram of speed control water supply system.
4. Figure 5.4 Energy distribution of the water supply system.
5. Figure 5.5 Pipe network characteristic curve.
6. Figure 5.6 Basic characteristic curve of pump.
7. Figure 5.7 Head and flow characteristic curve of pump.
8. Figure 5.8 Schematic diagram of constant pressure variable frequency speed control water supply system.
9. Figure 5.9 Control principle diagram of constant pressure water supply system.
10. Figure 5.10 Schematic diagram of AC–DC–AC converter circuit.
11. Figure 5.11 Output frequency–voltage characteristics of converter.
12. Figure 5.12 (a)–(d) Wiring diagram of pole changing windings.
13. Figure 5.13 Reverse pole changing method schematic of 2/4 poles. (a) Two poles and (b) 4 poles.
14. Figure 5.14 Four‐/six‐pole changing schematic of reverse method. (a) Four poles and (b) 6 poles.
15. Figure 5.15 The end wiring schematic of motor’s pole changing windings. (a) 2Y/∆, (b) Y/2Y, (c) 2∆/Y, and (d) 2Y/2Y.
16. Figure 5.16 Schematic diagram of multipump injection system.
17. Figure 5.17 Output volume and speed curve. 1, Frequency control; 2, pole changing speed regulation.
Chapter 06
1. Figure 6.1 The structure of a beam‐pumping unit. 1, Pedestal; 2, support; 3, hanging rope; 4, horsehead; 5, wiggle stick; 6, beam bearing; 7, beam; 8, connecting rod; 9, crankpin device; 10, crank device; 11, gear box; 12, brake safety device; 13, brake device; 14, motor; 15, distribution box.
2. Figure 6.2 The working principle diagram of reciprocating pump: (a) Up‐stroke and (b) down‐stroke. 1, Discharge valve; 2, plunger piston; 3, bushing; 4, suction valve.
3. Figure 6.3 The load torque curve of a beam pumping unit.
4. Figure 6.4 The mechanical characteristic curve of the ultra‐high slip motor.
5. Figure 6.5 The winding motor with an adaptive rotor resistance.
Chapter 07
1. Figure 7.1 Simplified equivalent circuit of induction motor.
2. Figure 7.2 Reactive compensation circuit of induction motor.
3. Figure 7.3 Reactive power compensation phasor diagram of induction motor.
4. Figure 7.4 The reactive power curve of 4‐pole motors.
5. Figure 7.5 The reactive power curve of 6‐pole motors.
6. Figure 7.6 The reactive power curve of 8‐pole motors.
7. Figure 7.7 30 kW, 4‐, 6‐, 8‐pole motors’ reactive power curve.
8. Figure 7.8 18.5 kW/4‐pole motor’s reactive power curve before and after compensation.
9. Figure 7.9 Local compensation mode. (a) Contactor control circuit and (b) air switching control circuit.
10. Figure 7.10 Connection mode through contactor. (a) Contactor control circuit and (b) air switching control circuit.
11. Figure 7.11 A connection mode with fuse.
12. Figure 7.12 A connection mode with discharging circuit.
13. Figure 7.13 Connection mode of dash current suppression.
14. Figure 7.14 The circuit theory block diagram of phased transistor dynamic compensation.
15. Figure 7.15 The synchronous phase detecting circuit.
16. Figure 7.16 Thyristor sync pulse trigger circuit.
17. Figure 7.17 The voltage‐type bridge SVG circuit schematic block diagram.
18. Figure 7.18 SVG equivalent circuit and phasor graph. (a) Equivalent circuit, (b) absorb the perceptual reactive power, and (c) absorb the capacitive reactive power.
19. Figure 7.19 SVG equivalent circuit and the phasor graph (the loss including). (a) Equivalent circuit, (b) current advance, and (c) current hysteresis.
20. Figure 7.20 SVG equivalent circuit and the phasor graph (the loss excluding). (a) Current advance and (b) current hysteresis.
21. Figure 7.21 Pumping unit motor active power curve.
22. Figure 7.22 Pumping unit motor reactive power curve.
23. Figure 7.23 Pumping unit motor power factor curve.
24. Figure 7.24 Fluctuation part of the dynamic compensation schematic diagram.
25. Figure 7.25 Fluctuation part of the dynamic compensation circuit schematic.
26. Figure 7.26 For the dynamic compensation part of the diagram.
27. Figure 7.27 Circuit of the dynamic compensation.

This edition first published 2018 by John Wiley & Sons Singapore Pte. Ltd under exclusive licence granted by China Machine Press for all media and languages (excluding simplified and traditional Chinese) throughout the world (excluding Mainland China), and with non‐exclusive license for electronic versions in Mainland China.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by law. Advice on how to obtain permission to reuse material from this title is available at http://www.wiley.com/go/permissions.

The right of Wenzhong Ma and Lianping Bai to be identified as the authors of this work has been asserted in accordance with law.

Registered Offices
John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, USA
John Wiley & Sons Singapore Pte. Ltd, 1 Fusionopolis Walk, #07‐01 Solaris South Tower, Singapore 138628

Editorial Office
1 Fusionopolis Walk, #07‐01 Solaris South Tower, Singapore 138628

For details of our global editorial offices, customer services, and more information about Wiley products visit us at www.wiley.com.

Wiley also publishes its books in a variety of electronic formats and by print‐on‐demand. Some content that appears in standard print versions of this book may not be available in other formats.

Limit of Liability/Disclaimer of Warranty
While the publisher and authors have used their best efforts in preparing this work, they make no representations or warranties with respect to the accuracy or completeness of the contents of this work and specifically disclaim all warranties, including without limitation any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives, written sales materials or promotional statements for this work. The fact that an organization, website, or product is referred to in this work as a citation and/or potential source of further information does not mean that the publisher and authors endorse the information or services the organization, website, or product may provide or recommendations it may make. This work is sold with the understanding that the publisher is not engaged in rendering professional services. The advice and strategies contained herein may not be suitable for your situation. You should consult with a specialist where appropriate. Further, readers should be aware that websites listed in this work may have changed or disappeared between when this work was written and when it is read. Neither the publisher nor authors shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages.

Library of Congress Cataloging‐in‐Publication data applied for

Hardback: 9781118981030

Cover design by Wiley
Cover image: Courtesy of Wenzhong Ma and Lianping Bai

About the Authors

Wenzhong Ma received B.S. and M.S.E. in Electrical Engineering from the Harbin Institute of Technology (1995), and Ph.D. in Electrical Engineering from the Institute of Electrical Engineering, Chinese Academy of Sciences (2006). Since 1995, he has been a faculty member at the China University of Petroleum, where he is a professor in the Department of Electrical Engineering.

He has taught a wide range of courses about electric machinery and power electronics, including Electric Machinery and Drive Systems, AC Variable Speed System, Power Electronics, Electric Circuit Analysis, and Electrical Energy‐saving Systems.

He has done extensive research in electric machine and drives, including motor design, motor drives, converters, electric power‐saving systems, and power electronic systems. From 2002 to 2006, he was involved in a national key project for Shanghai high‐speed maglev train systems, which is the first commercial high‐speed maglev train. He took charge of the commissioning and testing work of the long stator line motor, propulsion system, and power distribution systems. He has fulfilled the optimization of the long stator line motor system which is part of the Key Projects of the National High Technology Research and Development Program of China (863 Program).

He has authored five books: Energy Saving Principle and Technologies of Electric Machinery (China Machine Press, 2012), Electric Machinery and Drive Systems (China University of Petroleum Press, 2009), AC Variable Speed System (China University of Petroleum Press, 2013), Analysis of Advanced Electric Circuit (China University of Petroleum Press, 2010), and Experiment and Learning Guide of Electric Circuit (China University of Petroleum Press, 2007). He has published more than 40 papers, and he is also the inventor of three Chinese patents.

Lianping Bai graduated from Fuxin Mining College in 1982. He received M.S.E. in Electrical Engineering from the Harbin Institute of Technology (1990) and Ph.D. in Electrical Engineering from Xi’an Jiaotong University (2000). He was promoted to professor in 2001.

From 1982 to 1987, he served as a lecturer in Heilongjiang Mining college, where he taught courses on electrical automation in mining.

From 1990 to 1997, and from 2000 to 2005, he served in the China University of Petroleum; he taught a wide range of courses in Electrical Engineering, including Circuit Analysis, Electric Machinery and Drive Systems, Automatic Control System of the Electric Drives, Motor Energy‐saving Technology in Oil Field for undergraduates, Computer Control Technology of Electrical Drives, and Principle and Application of DSP for graduate students.

He has been working at Beijing Information Science and Technology University since 2006. He teaches Electrical Engineering courses, including Circuit Analysis, Motors and Drive, Motor Energy‐saving Technology, and so forth, for undergraduates; and Computer Control Technology of Electrical Drives, Motor Energy‐saving, and Testing Technology for graduate students.

From 1993, Mr. Bai engaged in the research on the principle of motor energy saving in oil fields and published 13 articles in this aspect. He has finished several research projects such as the research on double‐power energy‐saving motor and its control device, the research on energy‐saving technology with pole‐changing motors for water injection pump in an oil field, the research on winding‐type energy‐saving motor and its control device, and the development of on‐site testing technology and software for motors with a beam pumping unit.

He holds two Chinese patents: Beam Pumping Unit Energy‐saving Motor and Double‐Winding Series Energy‐saving Motor. These two patents (CN96249172.1 and CN99220167.5) are now widely applied in the Shengli Oil Field and other oil fields in China.

Preface

China has become a country of greater energy consumption nowadays, and energy supply shortage is getting worse and worse. This situation affects the economic development of the nation. Whatever the shortage is, there are still a lot of low‐usage and waste of energy. Therefore, energy saving is a long‐term policy for our social and economic development, as well as an urgent task for now. The government has set motor energy saving as one of the most important projects in the State Development Planning. This project requires technology and qualified scientists and technicians to implement the projects. Cultivating talents and training qualified personnel should start from university education. So it is necessary to set up a Motor Energy‐saving Course in the Department of Electrical Engineering and Automation. Nevertheless, there is no relevant textbook on this subject, even though a few relevant reference books can be found now. Therefore, the author has written this book based on the handouts of Motor Energy‐saving Technology and more than 10 years of study on motor energy saving. It can also be used as a reference book for workers engaged in this area.

The proportion of the installed capacity of a three‐phase induction motor makes up more than 80% of the total installed capacity of the motor. Consequently, the book mainly discusses the energy‐saving principle and method for three‐phase induction motors. At the same time, as the permanent magnet motor is an important developing direction of efficient motors, the book also introduces the principle and the application of efficient permanent magnet synchronous motors.

People often mention the power waste of motors, such as “big horse pulling small cart.” How can we define these problems? The book studies the variation rule of the motor efficiency and comprehensive efficiency curves, and defines the boundaries of the “big horse pulling small cart.” It also analyzes the variation of induction motor losses in the case of the “big horse pulling small cart.” The book also proposes some new ideas and new methods for induction motor energy saving. For example, the energy‐saving principle of a double power motor, and combined pole‐changing control for motors, and soft characteristics match. The field motor loss test method and the performance evaluation method for operating motors are also discussed. The efficiency reference value of rejection for used motors is also given. It puts forward the method of comparison evaluating for motor energy‐saving effect. It provides the curves of active power and reactive power and power factor for beam pumping unit motor. It puts forward the experimental research methods of motor reactive power compensation, as well as the method of motor hybrid dynamic reactive power compensation.

The book combines the motor energy‐saving principles, methods, techniques, and experience together, which shows the skill and experience to the reader, in order to enable readers to apply what they have learned. The book expounds the motor energy‐saving principle through the power and load match, speed match, and mechanical property match. First, the book introduced the three‐phase induction motor works and energy‐saving principle, then the motor energy‐saving methods with examples, and finally motor testing methods and evaluation methods. National standards are consistently reviewed in the book, in order to enable the reader to grasp the principle of motor energy saving, and in the meantime to be able to understand the standards and the usage of standard basis to follow when the instance and program options.

The motor energy‐saving technique is developed not only to increase the efficiency of the motor itself but also to improve the efficiency of the motor drive system. The motor energy saving is a broad field; the motor drive system involves many aspects. It can be noted that motor energy saving is a complicated system engineering. Improvements have been made in motor energy saving over the past decade, but it still has a long way to go. For instance, research on motor design theory; improving motor manufacturing processes; development of motor manufacturing materials; research on motor control technology; developing the technology of motor drive; and research on motor drive system theory.

Chapters 1, 3, and 4, and Sections 5.1, 5.5, and 5.6 are written by Lianping Bai, from Beijing Information Science & Technology University. Chapters 2, 6, and 7, and Sections 5.2–5.4 are written by Wenzhong Ma, from China University of Petroleum.

We would like to sincerely thank Professor Yanmin Su of Xi’an Jiaotong University for his review and valuable opinion during the preparation of the book. We would also like to thank the authors of references cited in the book. We would like to express our appreciation to Liang Zhang, Chun Zhang, and Yongliang Liang for their contribution to the book.

There may be errors or improper expressions in the book due to the limited knowledge of the authors. We sincerely welcome feedbacks and suggestions, which can be sent to mawenzhong@126.com. Thanks!

Wenzhong Ma and Lianping Bai
June 2016