Control of electrical drives / Werner Leonhard.

CONTENIDO
Introduction 1
1. Elementary Principles of Mechanics 7
Newtons Law 7
Moment of Inertia 9
Effect of Gearing 11
Power and Energy 12
Experimental Determination of Inertia 14
2. Dynamics of a Mechanical Drive 17
Equations Describing the Motion of a Drive with Lumped Inertia 17
Two Axes Drive in Polar Coordinates 20
Steady State Characteristics of Motors and Loads 22
Stable and Unstable Operating Points 26
3. Integration of the Simplified Equation of Motion 29
Solution of the Linearised Equation 29
Start of a Motor with Shunt-type Characteristic at No-load 30
Starting the Motor with a Load Torque Proportional to Speed 32
Loading Transient of the Motor Initially Running at No-load Speed 33
Starting of a DC Motor by Sequentially Short-circuiting Starting Resistors 35
Analytical Solution of Nonlinear Differential Equation 38
Numerical and Graphical Integration 39
4. Thermal Effects in Electrical Machines 43
Power Losses and Temperature Restrictions 43
Heating of a Homogeneous Body 44
Different Modes of Operation 48
Continuous Duty 48
Short Time Intermittent Duty 48
Periodic intermittent Duty 49
5. Separately Excited DC Machine 51
Introduction 51
Mathematical Model of the DC Machine 54
Steady State Characteristics with Armature and Field Control 56
Armature Control 57
Field Control 58
Combined Armature and Field Control 61
Dynamic Behaviour of DC Motor with Constant Flux 64
6. DC Motor with Series Field Winding 69
Block Diagram of a Series-wound Motor 70
Steady State Characteristics 73
7. Control of a Separately Excited DC Machine 77
Introduction 77
Cascade Control of DC Motor in the Armature Control Region 79
Cascade Control of DC Motor in the Field-weakening Region 90
Supplying a DC Motor from a Rotating Generator 93
8. Static Converter as a Power Actuator for DC Drives 97
Electronic Switching Devices 97
Line-commutated Converter in Single-phase Bridge Connection 102
Line-commutated Converter in Three-phase Bridge Connection 119
Line-commutated Converters with Reduced Reactive Power 130
Control Loop Containing an Electronic Power Converter 133
9. Control of Converter-supplied DC Drives 139
DC Drive with Line-commutated Converter 139
DC Drives with Force-commutated Converters 148
10. Symmetrical Three-Phase AC Machines 163
Mathematical Model of a General AC Machine 164
Induction Motor with Sinusoidal Symmetrical Voltages in Steady State 176
Stator Current, Current Locus 176
Steady State Torque, Efficiency 182
Comparison with Practical Motor Designs 186
Starting of the Induction Motor 187
Induction Motor with Impressed Voltages of Arbitrary Wave-forms 190
Induction Motor with Unsymmetrical Line Voltages in Steady State 202
Symmetrical Components 202
Single-phase Induction Motor 206
Single-phase Electric Brake for AC Crane-Drives 209
Unsymmetrical Starting Circuit for Induction Motor 211
11. Power Supplies for Adjustable Speed AC Drives 215
Pulse width modulated (PWM) Voltage Source Transistor Converter (IGBT) 218
Voltage Source PWM Thyristor Converter 225
Current Source Thyristor Converters 232
Converter Without DC Link (Cycloconverter) 236
12. Control of Induction Motor Drives 241
Control of Induction Motor Based on Steady State Machine Model 242
Rotor Flux Orientated Control of Current-fed Induction Motor 252
Principle of Field Orientation 252
Acquisition of Flux Signals 260
Effects of Residual Lag of the Current Control Loops 262
Digital Signal Processing 265
Experimental Results 268
Effects of a Detuned Flux Model 269
Control of Voltage-fed Induction Motor 275
Field Orientated Control of Induction Motor with a Current Source Converter 281
Control of an Induction Motor without a Mechanical Sensor 289
Machine Model in Stator Flux Coordinates 289
Example of an "Encoderless Control" 291
Simulation and Experimental Results 296
Control of an Induction Motor Using a Combined Flux Model 298
13. Induction Motor Drive with Reduced Speed Range 303
Doubly-fed Induction Machine with Constant Stator Frequency and Field-orientated Rotor Current 303
Control of a Line-side Voltage Source Converter as a Reactive Power Compensator 317
Wound-Rotor Induction with Slip-Power Recovery 323
14. Variable Frequency Synchronous Motor Drives 329
Control of Synchronous Motors with PM Excitation 331
Synchronous Motor with Field- and Damper-Windings 342
Synchronous Motor with Load-commutated Inverter (LCI-Drive) 349
15. Some Applications of Controlled Electrical Drives 363
Speed Controlled Drives 364
Linear Position Control 373
Linear Position Control with Moving Reference Point 383
Time-optimal Position Control with Fixed Reference Point 389
Time-optimal Position Control with Moving Reference Point 396
Bibliography 402
Index 455