Bahram Amin Induction Motors Analysis and Torque Control With 41 Figures and 50 diagrams (simulation plots) Springer
1 Main Parameters of Induction Motors 1.1 Introduction 1 1.2 Structural Elements of Induction Motors 2 1.3 Parameter Calculation 7 2 Electromagnetic Space Vectors and General Equivalent Circuits 2.1 Introduction 13 2.2 Magneto-Motive Forces and Currents 14 2.3 Magnetic Energy Stored In the Machine - Magnetizing Energy 22 2.4 Torque 24 2.5 Voltage Equations 25 2.6 General Equivalent Circuits 26 2.7 Power Considerations 29 3 Steady-State Three-Phase Induction Motors 3.1 Introduction 33 3.2 Statement of the Problem 33 3.3 Determination of the Equivalent Circuit Parameters 38 3.4 Magnetizing Energy and Torque 41 3.5 Input Impedance and Admittance - Current-Transfer Ratio...41 3.6 Voltage-Source Line-Fed Induction Motors Under Steady- State Conditions 44 3.6.1 Phase Currents 44 3.6.2 Torque 45 3.6.3 Magnetizing Energy 46 3.6.4 Full-Load Regime 47 3.6.5 Order of Magnitude of Variables in a Voltage-Source Line-Fed Induction Motor 49 3.6.6 Line-Fed Induction Motors at Start-up 51 3.7 Power Considerations 52 3.8 Current-Source Line-Fed Induction Motors 54 3.8.1 Magnetizing Energy 54
3.8.2 Torque 55 3.8.3 Order of Magnitude of Variables in a Current-Source Line-Fed Induction Motor 57 3.8.4 Current-Source Line-Fed Induction Motors at Start- Up 58 3.9 Negative-Sequence Applied Voltages 59 3.10 Induction Motors Fed from Unbalanced Voltage Source...62 3.10.1 Phase Currents 64 3.10.2 Magnetizing Energy 64 3.10.3 Torque 64 3.11 Asymmetric Three-Phase Induction Motors in Steady- State Regimes 67 4 Steady-State Single-Phase Induction Motors 4.1 Introduction 77 4.2 Equations for Single-Phase Motors 79 4.2.1 Stator Currents 80 4.2.2 Rotor Currents 80 4.2.3 Magnetizing Energy 81 4.2.4 Torque 82 4.3 Line-Fed Single-Phase Induction Motors 83 4.3.1 Line Voltage 83 4.3.2 Magnetizing Energy and Torque 85 4.3.3 Phase Current 87 4.4 Equivalent Circuit 87 4.5 Determination of the Equivalent Circuit Parameters 91 5 Induction Motors in Transient Regimes 5.1 Introduction 95 5.2 Operating Equations in Transient Regimes 96 5.3 Transient Analysis in the Time Domain 96 5.3.1 Electromagnetic Transients with Rapidly Changing Angular Velocity 97 5.3.2 Electromagnetic Transients with Slowly Changing Angular Velocity 98 5.3.3 Transient Analysis of Inverter-Fed Induction Motors 100 5.4 Transient Analysis in the Frequency Domain 102 5.5 Examples of Simulation 104 5.5.1 Start-Up from Standstill 104
XI 5.5.2 Take-Over of a De-Energized Motor 105 5.5.3 Inverter-Fed Induction Motors with Frozen Power Switches 105 6 Inverter-Fed Induction Motors 6.1 Introduction 109 6.2 Voltage-Source Inverters 110 6.3 Natural Pulse Pattern of Inverters 112 6.3.1 Natural Pulse Pattern of a Two-Level Inverter 112 6.3.2 Natural Pulse Pattern of a Three-Level Inverter 113 6.4 Scanning Modes...115 6.4.1 Periodic Scanning Modes - Output Waveforms 115 6.5 Spectral Analysis of Periodic Waveforms - Total Harmonic Distortion 117 6.6 Space Vector Modulation 118 6.6.1 Basic Idea 118 6.6.2 Uniform Waveforms Obtained Using Space Vector Modulation 121 6.6.3 Required Switching Frequency 122 6.6.4 Output Current Waveforms 123 6.7 Voltage Space Vector Applied Across the Load 124 6.7.1 Y-Connected Load 124 6.7.2 A-Connected Load 124 6.8 Harmonics 125 6.9 Voltage Harmonics 126 6.9.1 Harmonic Components of Single-Pulse Waveforms 126 6.9.2 Harmonic Components of P-Pulse Waveforms 128 6.9.3 Harmonic Components of Uniform Waveforms 130 6.9.4 Harmonic Components of Quasi-Uniform Waveforms 137 6.9.5 Harmonic Components of Modulated Waveforms.. 142 6.10 Current Harmonics 148 6.10.1 Current Harmonics in Various Load Phases 148 6.10.2 Current Harmonics of Input Lines 149 6.11 Current-Source Inverters 150 7 Induction Motors Torque Control 7.1 Introduction 157 7.2 Vector Control 158
XII Contents 7.2.1 Principle of the Computed Charge Acceleration Method (C.C.A.M) 159 7.2.2 Implementation of the C.C.A.M 162 7.2.3 Other Vector Control Approaches 168 7.2.4 Vector Control Simulation Results 170 7.3 Scalar Control 179 7.3.1 Scalar Control Principle 180 7.3.2 Scalar Control Operating Conditions 182 7.3.3 Scalar Control Simulation Results 190 7.4 Evaluation of the Statorand Rotor Resistance 198 7.5 Principle of Speed Calculation 202 7.6 Speed Regulation 203 Appendix A Field-Oriented Control A.1 Introduction 205 A.2 Preliminary Investigations 205 A.3 Field-Oriented Control 207 Appendix B Direct Torque Control B.1 Introduction 213 B.2 Direct Torque Control Principle 213 Appendix C Double-Cage Induction Motors C.1 Introduction 217 C.2 Voltage Equations in Double-Cage Induction Motors 217 C.3 General Equivalent Circuit of Double-Cage Induction Motors 219 C.4 Steady-State Equivalent Circuit of Double-Cage Induction Motors 222 Appendix D Transient Analysis in Single-Phase Induction Motors D.1 Introduction 225 D.2 Transients in Three-Phase Induction Motors 225 D.3 Transients in Single-Phase Induction Motors 227
XIII Appendix E Synchronous Motors Torque Control E.1 Introduction 229 E.2 Operating Equations of Cylindrical-Rotor Synchronous Motors 230 E.3 Torque Control of Cylindrical-Rotor Synchronous Motors 233 E.4 Examples of Simulations 234 E.5 Operating Equations for Salient-Pole Synchronous Motors 237 E.6 Torque Control of Salient-Pole Synchronous Motors 239 E.7 Operating Equations for Synchronous Machines with Damper Cages and Field Winding 242 E.7.1 Cylindrical-Rotor Synchronous Machines 244 E.7.2 Salient-Pole Synchronous Machines 252 References 257 Subject Index 259