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"This book is an in-depth essential reference of rotating electrical machine design theory and application. In the first part of the book the general theory governing the design of an electrical machine is presented; addressing the necessary fundamentals of electromagnetic theory; exploring possible winding arrangements and resistances; describing the behaviour of the magnetic circuit and flux leakage. After this introduction of principles the main body of the book focuses on the design of a rotating electrical machine. The book defines basic characteristics such as machine type (e.g. synchronous, asynchronous, DC and doubly salient reluctance machines) and type of construction (e.g. external pole, internal pole, axial flux and radial flux machines).It then moves on to provide a detailed analysis of the design process and properties of rotating electrical machines including the insulation and heat removal options. The book illustrates the necessary analytical calculations for machine design throughdirect design examples i.e. a permanent magnet motor for normal speeds with rotor surface magnets, traditional squirrel cage induction motor, a low speed high torque fractional slot permanent magnet motor etc. "--
List of contents
Preface xi
About the Authors xiii
Abbreviations and Symbols xv
1 Principal Laws and Methods in Electrical Machine Design 1
1.1 Electromagnetic Principles 1
1.2 Numerical Solution 8
1.3 The Most Common Principles Applied to Analytic Calculation 12
1.3.1 Flux Line Diagrams 16
1.3.2 Flux Diagrams for Current-Carrying Areas 22
1.4 Application of the Principle of Virtual Work in the Determination of Force and Torque 25
1.5 Maxwell's Stress Tensor; Radial and Tangential Stress 32
1.6 Self-Inductance and Mutual Inductance 36
1.7 Per Unit Values 42
1.8 Phasor Diagrams 45
Bibliography 47
2 Windings of Electrical Machines 48
2.1 Basic Principles 49
2.1.1 Salient-Pole Windings 49
2.1.2 Slot Windings 53
2.1.3 End Windings 54
2.2 Phase Windings 54
2.3 Three-Phase Integral Slot Stator Winding 57
2.4 Voltage Phasor Diagram and Winding Factor 64
2.5 Winding Analysis 72
2.6 Short Pitching 74
2.7 Current Linkage of a Slot Winding 81
2.8 Poly-Phase Fractional Slot Windings 94
2.9 Phase Systems and Zones of Windings 97
2.9.1 Phase Systems 97
2.9.2 Zones of Windings 99
2.10 Symmetry Conditions 101
2.10.1 Symmetrical Fractional Slot Windings 101
2.11 Base Windings 104
2.11.1 First-Grade Fractional Slot Base Windings 104
2.11.2 Second-Grade Fractional Slot Base Windings 105
2.11.3 Integral Slot Base Windings 106
2.12 Fractional Slot Windings 108
2.12.1 Single-Layer Fractional Slot Windings 108
2.12.2 Double-Layer Fractional Slot Windings 117
2.13 Single- and Double-Phase Windings 124
2.14 Windings Permitting a Varying Number of Poles 127
2.15 Commutator Windings 129
2.15.1 Lap Winding Principles 133
2.15.2 Wave Winding Principles 136
2.15.3 Commutator Winding Examples, Balancing Connectors 139
2.15.4 AC Commutator Windings 143
2.15.5 Current Linkage of the Commutator Winding and Armature Reaction 144
2.16 Compensating Windings and Commutating Poles 146
2.17 Rotor Windings of Asynchronous Machines 149
2.18 Damper Windings 152
Bibliography 153
3 Design of Magnetic Circuits 155
3.1 Air Gap and its Magnetic Voltage 161
3.1.1 Air Gap and Carter Factor 161
3.1.2 Air Gaps of a Salient-Pole Machine 166
3.1.3 Air Gap of Nonsalient-Pole Machine 172
3.2 Equivalent Core Length 173
3.3 Magnetic Voltage of a Tooth and a Salient Pole 176
3.3.1 Magnetic Voltage of a Tooth 176
3.3.2 Magnetic Voltage of a Salient Pole 180
3.4 Magnetic Voltage of Stator and Rotor Yokes 180
3.5 No-Load Curve, Equivalent Air Gap and Magnetizing Current of the Machine 183
3.6 Magnetic Materials of a Rotating Machine 186
3.6.1 Characteristics of Ferromagnetic Materials 189
3.6.2 Losses in Iron Circuits 194
3.7 Permanent Magnets in Rotating Machines 203
3.7.1 History and Development of Permanent Magnets 203
3.7.2 Characteristics of Permanent Magnet Materials 205
3.7.3 Operating Point of a Permanent Magnet Circuit 210
3.7.4 Demagnetization of Permanent Magnets 217
3.7.5 Application of Permanent Magnets in Electrical Machines 219
3.8 Assembly of Iron Stacks 226
Bibliography 227
4 Inductances 229
4.1 Magnetizing Inductance 230
4.2 Leaka
Report
"The insight gained by this book will provide the reader with an advantage in understanding the inner workings of motors and to be able to optimize designs for maximum efficiency." ( IEEE Electrical Insulation Magazine , 1 November 2014)
