AC Machine Systems (eBook)

Abstract 5
Preface 6
Introduction 8
Table of Contents 12
1 Circuit Analysis of AC Machines—Multi-Loop Model and Parameters 15
1.1 Electromagnetic Relations of AC Machine Loops 16
1.1.1 Stator Loops 17
1.1.2 Excitation Loop 18
1.1.3 Damper Loops 18
1.2 Air-Gap Permeance Coefficient of Electric Machines 20
1.3 Air-Gap Magnetic Field Produced by Single Coil and the Corresponding Inductance 22
1.3.1 Air-Gap MMF Produced by Single Coil’s Current 23
1.3.2 Air-Gap Magnetic Field Produced by Single Coil’s Current 25
1.3.3 Self Inductance of Single Coil 27
1.3.4 Mutual Inductance Between Coils 30
1.4 Inductances of Stator Loops 33
1.5 Inductances of Rotor Loops 37
1.5.1 Inductance of Excitation Winding 37
1.5.2 Inductance of Damper Winding 38
1.5.3 Mutual Inductance Between Excitation Winding and Damping Loop 44
1.6 Mutual Inductances Between Stator Loops and Rotor Loops 46
1.7 Influence of Saturation on Parameters 48
1.8 Inductances Produced by Leakage Magnetic Field 51
1.8.1 Inductance Produced by Rotor Leakage Magnetic Field 51
1.8.2 Inductances Produced by Stator Leakage Magnetic Field 52
1.9 Electromagnetic Torque and Rotor Motion Equation of AC Machines 54
1.10 Analysis of Parameters and Performance of Single- Phase Induction Motors 58
1.10.1 Inductances of Single Phase Induction Machine 59
1.10.2 Basic Relations of Single Phase Induction Machine 66
References 70
2 Electromagnetic Relations and Parameters of Synchronous Machines and Analysis of Their Several Operating Conditions at Synchronous Speed 72
2.1 Basic Relations of Synchronous Machines 73
2.1.1 Inductances of Stator Phase Windings 75
2.1.2 Inductances Between Stator and Rotor Windings 82
2.1.3 3-Phase Synchronous Machine Inductances in Accordance with Fundamental Air-Gap Flux 88
2.2 Basic Relations of Synchronous Machines in d, q, 0 Axes 92
2.2.1 Flux-Linkages and Parameters of Stator Phase Windings 92
2.2.2 Flux-linkages and Parameters of Rotor Windings 101
2.2.3 Voltage Equations of Synchronous Machines 102
2.2.4 Park’s Formulas of Synchronous Machines 103
2.3 Per-Unit Systems in Synchronous Machines 103
2.3.1 Per-Unit System of Reversible Mutual Inductances 104
2.3.2 Park’s Per-Unit System of Irreversible Mutual Inductances 110
2.4 Basic Equations in Per-Unit, Operational Reactances and Electromagnetic Torque of Synchronous Machines 114
2.4.1 Basic Equations in Per-Unit of Synchronous Machines 114
2.4.2 Equivalent Circuits and Operational Reactances of Synchronous Machines 116
2.4.3 Output Power and Electromagnetic Torque in Synchronous Machines 123
2.5 3-Phase Sudden Short Circuit and Transient Parameters of Synchronous Machines 125
2.5.1 Original Steady-State Operation Condition 125
2.5.2 Current Components Caused by 3-phase Sudden Short Circuit 131
2.5.3 Currents after 3-phase Sudden Short Circuit of Synchronous Machines 148
2.6 Voltage Dip during Sudden Increase of Load for Synchronous Machines 156
2.7 Transient EMFs of Synchronous Machines 161
2.8 Electromagnetic Torque after 3-Phase Sudden Short Circuit 167
2.9 Suddenly Opening 3-phase Short Circuit of Synchronous Machines 173
References 179
3 Some Special Operation Modes of Synchronous Machine Systems at Constant Speed and Variable Speed 180
3.1 Transformations of Reference Axes Systems and Their Formulas in Synchronous Machines 182
3.2 2-Phases Sudden Short Circuit of Synchronous Machines 194
3.3 Steady-state Asynchronous Operation of Synchronous Machines 217
3.4 Asynchronously Starting of Synchronous Motors 228
3.5 Analysis of Combination System for Synchronous Machine and Capacitances 238
3.6 Mathematic Model and Performance Analysis of Cycloconverter-fed Synchronous Motor Systems with Field-Oriented Control 249
3.6.1 Mathematical Patterns of the Cycloconverter-fed Synchronous Motor System 250
3.6.2 Simulation and Performance Analysis of Cycloconverter-fed Synchronous Motor Systems 256
3.6.3 Design of Damping Winding for Cycloconverter-fed Synchronous Motors with Field-oriented Control 262
3.7 Analysis of Synchronous Generators with AC and DC Stator Connections 263
3.7.1 Mathematical Model of AC-DC Generators and Loads 265
3.7.2 System Equation of ac-dc generator 267
3.7.3 Model of Rectifier Bridge 270
3.7.4 Model of Automatic Voltage Regulator (AVR) 272
3.7.5 Motion Equation of Rotor and Speed Regulators 273
3.7.6 Simulation Procedure of AC-DC Generator System 274
3.7.7 Verification of Simulation Program 275
3.7.8 Simulation Research of Voltage Harmonics of AC-DC Generators 277
References 280
4 Oscillation, Stability and Excitation Regulation of Synchronous Machine Systems 281
4.1 Small perturbation and Linearization of AC Machine Systems 282
4.2 Steady-State Small Oscillation and Torque Coefficients of Synchronous Machine Systems 284
4.3 Static Stability of Synchronous Machine Systems and Influence of Excitation Regulation on Static Stability 315
4.3.1 Basic Relations of Synchronous Machine Systems for Analyzing Static Stability 316
4.3.2 Approximate Analysis of Static Stability for Synchronous Machine Systems 318
4.3.3 Influence of Excitation Regulation on Static Stability 325
4.4 Dynamic Stability and Analysis Methods of Synchronous Machine Systems 329
4.4.1 The Equations Corresponding to Analysis of Dynamic Stability for Synchronous Machine Systems 330
4.4.2 Mathematical Patterns Corresponding to Analysis of Dynamic Stability for Synchronous Machine Systems 339
4.4.3 Calculation Example of Dynamic Stability for Synchronous Machine Systems 340
References 352
5 Electromagnetic Relations of Induction Machine Systems and Analyses of Some Operating Modes 353
5.1 Basic Relations and Parameters of Induction Machines 354
5.1.1 Wound-Rotor Induction Machines 355
5.1.2 Squirrel-cage Rotor Induction Machines 361
5.2 Basic Relations and Parameters of Induction Machines in d, q, 0 Axes 368
5.3 Analysis of the Starting Process of Induction Motors 377
5.3.1 Basic Equations for the Analysis of Starting Process 378
5.3.2 Numerical Calculation of Starting Characteristics 379
5.3.3 Comparison and Analysis of Calculation Results in Two Ways 380
5.4 Transients of Reswitching on Induction Motors 385
5.4.1 Transients of Induction Motors after Disconnection 386
5.4.2 Transients of Induction Motors after Reclosing 395
5.4.3 Transients of Induction Motors after Flux-extinguishing Resistors are Connected in Stator Circuit 398
5.5 Self-Excitation when Connecting Induction Motor in Series with Capacitance and Counting the Inertia Effect in 400
5.5.1 Basic Equations of Induction Machines when Counting the Inertia Effect in 400
5.5.2 Basic Relations of Induction Machines in Steady-state 404
5.5.3 Small Perturbation Equations of Induction Machines 407
5.5.4 Determination of Self-excitation Region for Induction Machines when Counting the Inertia Effect in 409
5.5.5 Effect of Inertia Constant on Self-excitation Region 411
5.6 Dual-Stator-Winding Multi-Phase High-Speed Induction Generator 416
5.6.1 Construction of New Induction Generator 416
5.6.2 MMF of Multi-Phase Induction Generator 417
5.6.3 Circuit Method for the System of Power Winding with Rectifier Load 419
5.6.4 Field Method for the System of Dual-Winding-Stator and Solid Cage Rotor 422
References 425
6 Internal Asymmetric Analysis of AC Machines 426
6.1 Analysis of Rotor Winding Failures of Squirrel Cage 3-Phase Induction Machines 429
6.1.1 Basic Equations of Squirrel Cage Three Phase Induction Machine 430
6.1.2 Calculation of Loop Inductances of Squirrel Cage Three Phase Induction Machine 431
6.1.3 Amending Basic Equations Based on Rotor Failure Condition 433
6.1.4 Calculation of Steady State Loop Currents 435
6.2 Internal Fault Analysis of Stator Winding of Salient Pole Synchronous Machines 445
6.2.1 Mathematic Model of Stator Winding Internal Fault of Salient Pole Synchronous Machine 446
6.2.2 Loop Parameters of Stator Winding Internal Faults of Synchronous Machine 454
6.2.3 Calculation of Steady State for Internal Fault of Salient Pole Synchronous Machine 455
6.2.4 Calculation of Transients for Internal Fault of Salient Pole Synchronous Machine 457
6.2.5 Features of Internal Faults of Salient Pole Synchronous Machine 459
6.3 Internal Fault Analysis of Stator Winding of Non-Salient Pole Synchronous Machines 461
6.3.1 Mathematic Model of Stator Winding Internal Fault of Non-salient Pole Synchronous Machine 462
6.3.2 Calculation and Experiments of Internal Faults of Non-salient Pole Synchronous Machine 464
References 468
Appendix A Air-Gap Permeance Coefficients in Consideration of Slot Effect 469
Appendix B Expressions of Effective Air-Gap 472
Appendix C Inductances Due to Leakage Flux of Stator Winding End 475
Appendix D Heaviside’s Operational Calculus and Its Application to Transients Analysis 488
Appendix E Basic Relations and Equivalent Circuits of Transformers 494
Index 498