Advanced Electric Drives: Analysis, Control, and Modeling Using MATLAB / Simulink

199 Pages·2014·2.27 MB·English

by  Ned Mohan

ADVANCED
ELECTRIC DRIVES

ADVANCED
ELECTRIC DRIVES
Analysis, Control, and Modeling
Using MATLAB/Simulink®
Ned Mohan
Copyright © 2014 by John Wiley & Sons, Inc. All rights reserved.
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Library of Congress Cataloging-in-Publication Data:
Mohan, Ned.
Advanced electric drives : analysis, control, and modeling using MATLAB/Simulink® / Ned
Mohan.
pages cm
Includes index.
ISBN 978-1-118-48548-4 (hardback)
1. Electric driving–Computer simulation. 2. Electric motors–Mathematical
models. 3. MATLAB. 4. SIMULINK. I. Title.
TK4058.M5783 2014
621.460285'53–dc23
2014005496
Printed in the United States of America.
10 9 8 7 6 5 4 3 2 1
CONTENTS
Preface xiii
Notation xv
1 Applications: Speed and Torque Control 1
1-1 History 1
1-2 Background 2
1-3 Types of ac Drives Discussed and the
Simulation Software 2
1-4 Structure of this Textbook 3
1-5 “Test” Induction Motor 3
1-6 Summary 4
References 4
Problems 4
2 Induction Machine Equations in Phase Quantities:
Assisted by Space Vectors 6
2-1 Introduction 6
2-2 Sinusoidally Distributed Stator Windings 6
2-2-1 Three-Phase, Sinusoidally Distributed
Stator Windings 8
2-3 Stator Inductances (Rotor Open-Circuited) 9
2-3-1 Stator Single-Phase Magnetizing
Inductance L 9
m,1-phase
2-3-2 Stator Mutual-Inductance L 11
mutual
2-3-3 Per-Phase Magnetizing-Inductance L 12
m
2-3-4 Stator-Inductance L  12
s
2-4 Equivalent Windings in a Squirrel-Cage Rotor 13
2-4-1 Rotor-Winding Inductances
(Stator Open-Circuited) 13
v
vi CONTENTS
2-5 Mutual Inductances between the Stator and
the Rotor Phase Windings 15
2-6 Review of Space Vectors 15
2-6-1 Relationship between Phasors and Space
Vectors in Sinusoidal Steady State 17
2-7 Flux Linkages 18
2-7-1 Stator Flux Linkage (Rotor
Open-Circuited) 18
2-7-2 Rotor Flux Linkage (Stator
Open-Circuited) 19
2-7-3 Stator and Rotor Flux Linkages
(Simultaneous Stator and
Rotor Currents) 20
2-8 Stator and Rotor Voltage Equations in Terms of
Space Vectors 21
2-9 Making the Case for a dq-Winding Analysis 22
2-10 Summary 25
Reference 25
Problems 26
3 Dynamic Analysis of Induction Machines in Terms
of dq Windings 28
3-1 Introduction 28
3-2 dq Winding Representation 28
3-2-1 Stator dq Winding Representation 29
3-2-2 Rotor dq Windings (Along the Same
dq-Axes as in the Stator) 31
3-2-3 Mutual Inductance between dq Windings
on the Stator and the Rotor 32
3-3 Mathematical Relationships of the dq Windings
(at an Arbitrary Speed ω ) 33
d
3-3-1 Relating dq Winding Variables to Phase
Winding Variables 35
3-3-2 Flux Linkages of dq Windings in Terms
of Their Currents 36
3-3-3 dq Winding Voltage Equations 37
CONTENTS vii
3-3-4 Obtaining Fluxes and Currents with
Voltages as Inputs 40
3-4 Choice of the dq Winding Speed ω   41
d
3-5 Electromagnetic Torque 42
3-5-1 Torque on the Rotor d-Axis Winding 42
3-5-2 Torque on the Rotor q-Axis Winding 43
3-5-3 Net Electromagnetic Torque T on
em
the Rotor 44
3-6 Electrodynamics 44
3-7 d- and q-Axis Equivalent Circuits 45
3-8 Relationship between the dq Windings and
the Per-Phase Phasor-Domain Equivalent
Circuit in Balanced Sinusoidal
Steady State 46
3-9 Computer Simulation 47
3-9-1 Calculation of Initial Conditions 48
3-10 Summary 56
Reference 56
Problems 57
4 Vector Control of Induction-Motor Drives:
A Qualitative Examination 59
4-1 Introduction 59
4-2 Emulation of dc and Brushless dc
Drive Performance 59
4-2-1 Vector Control of Induction-Motor
Drives 61
4-3 Analogy to a Current-Excited Transformer with
a Shorted Secondary 62
4-3-1 Using the Transformer
Equivalent Circuit 65
4-4 d- and q-Axis Winding Representation 66
4-5 Vector Control with d-Axis Aligned with the
Rotor Flux 67
4-5-1 Initial Flux Buildup Prior to t = 0−  67
4-5-2 Step Change in Torque at t = 0+  68
viii CONTENTS
4-6 Torque, Speed, and Position Control 72
4-6-1 The Reference Current i* (t) 72
sq
4-6-2 The Reference Current i* (t) 73
sd
4-6-3 Transformation and Inverse-Transformation
of Stator Currents 73
4-6-4 The Estimated Motor Model for
Vector Control 74
4-7 The Power-Processing Unit (PPU) 75
4-8 Summary 76
References 76
Problems 77
5 Mathematical Description of Vector Control in
Induction Machines 79
5-1 Motor Model with the d-Axis Aligned Along the
(cid:31)
Rotor Flux Linkage λ-Axis 79
r
5-1-1 Calculation of ω   81
dA
5-1-2 Calculation of T   81
em
5-1-3 d-Axis Rotor Flux Linkage Dynamics 82
5-1-4 Motor Model 82
5-2 Vector Control 84
5-2-1 Speed and Position Control Loops 86
5-2-2 Initial Startup 89
5-2-3 Calculating the Stator Voltages to
Be Applied 89
5-2-4 Designing the PI Controllers 90
5-3 Summary 95
Reference 95
Problems 95
6 Detuning Effects in Induction Motor Vector Control 97
6-1 Effect of Detuning Due to Incorrect Rotor
Time Constant τ  97
r
6-2 Steady-State Analysis 101
6-2-1 Steady-State i /i* 104
sd sd
6-2-2 Steady-State i /i* 104
sq sq