Axial Flux Permanent Magnet Brushless Machines

Introduction; 1.1 Scope; 1.2 Features; 1.3 Development of AFPM Machines; 1.4 Types of Axial Flwr PM Machines; 1.5 Topologies and Geometries; 1.6 Rotor Dynamics; 1.7 Axial Magnetic Field Excited by PMs; 1.8 PM Eddy-Current Brake as the Simplest AFPM Brushless Machine; 1.9 AFPM Machines versus RFPM Machines; 1.10 Power Limitation of AFPM Machines; Numerical Examples; 2 Principles of AFPM Machines; 2.1 Magnetic Circuits; 2.1.1 Single-Sided Machines; 2.1.2 Double-Sided Machines With Internal PM DiscRotor; 2.1.3 Double-Sided Machines With Internal Ring-Shaped Core Stator; 2.1.4 Double-Sided Machines With Internal Slotted Stator; 2.1.5 Double-Sided Machines With Internal Coreless Stator; 2.1.6 Multidisc Machines; 2.2 Windings; 2.2.1 Three-Phase Windings Distributed in Slots; 2.2.2 Toroidal Winding; 2.2.3 Coreless Stator Winding; 2.2.4 Non-Overlap (Salient Pole) Windings; 2.3 Torque Production; 2.4 Magnetic Flux; 2.5 Electromagnetic Torque and EMF; 2.6 Losses and Efficiency; 2.6.1 Stator Winding Losses; 2.6.2 Stator Core Losses; 2.6.3 Core Loss Finite Element Model; 2.6.4 Losses in Permanent Magnets; 2.6.5 Rotor Core Losses; 2.6.6 Eddy Current Losses in Stator Conductors; 2.6.7 Rotational Losses; 2.6.8 Losses for Nonsinusoidal Current; 2.6.9 Efficiency; 2.7 Phasor Diagrams; 2.8 Sizing Equations; 2.9 Armature Reaction; 2.10 AFPM Motor; 2.10.1 Sine-Wave Motor; 2.10.2 Square-Wave Motor; 2.11 AFPM Synchronous Generator; 2.11.1 Performance Characteristics of a Stand Alone Generator; 2.11.2 Synchronization With Utility Grid; Numerical Examples; 3 Materials and Fabrication; 3.1 Stator Cores; 3.1.1 Nonoriented Electrical Steels; 3.1.2 Amorphous Ferromagnetic Alloys; 3.1.3 Soft Magnetic Powder Composites; 3.1.4 Fabrication of Stator Cores; 3.2 Rotor Magnetic Circuits; 3.2.1 PM Materials; 3.2.2 Characteristics of PM Materials; 3.2.3 Operating Diagram; 3.2.4 Permeances for Main and Leakage Fluxes; 3.2.5 Calculation of Magnetic Circuits With PMs; 3.2.6 Fabrication of Rotor Magnetic Circuits; 3.3 Windings; 3.3.1 Conductors; 3.3.2 Fabrication of Slotted Windings; 3.3.3 Fabrication of Coreless Windings; Numerical Examples; 4 AFPM Machines With Iron Cores; 4.1 Geometries; 4.2 Commercial AFPM Machines With Stator Ferromagnetic Cores; 4.3 Some Features of Iron-Cored AFPM Machines; 4.4 Magnetic Flux Density Distribution in the Air Gap; 4.5 Calculation of Reactances; 4.5.1 Synchronous and Armature Reaction Reactances; 4.5.2 Stator Leakage Reactance; 4.6 Performance Characteristics; 4.7 Performance Calculation; 4.7.1 Sine-Wave AFPM Machine; 4.7.2 Synchronous Generator; 4.7.3 Square-Wave AFPM Machine; 4.8 Finite Element Calculations; Numerical Examples; 5 AFPM Machines Without Stator Cores; 5.1 Advantages and Disadvantages; 5.2 Commercial Coreless Stator AFPM Machines; 5.3 Coreless Stator AFPM Microgenerators; 5.4 Performance Calculation; 5.4.1 Steady-State Performance; 5.4.2 Dynamic Performance; 5.5 Calculation of Coreless Winding Inductances; 5.5.1 Classical Approach; 5.5.2 FEM Approach; 5.6 Performance Characteristics; 5.7 Performance of Coreless Non-Overlap Winding AFPM Machines; 5.8 Eddy Current Losses in the Stator Windings; 5.8.1 Eddy Current Loss Resistance; 5.8.2 Reduction of Eddy Current Losses; 5.8.3 Reduction of Circulating Current Losses; 5.8.4 Measurement of Eddy Current Losses; 5.9 Armature Reaction; 5.10 Mechanical Design Features; 5.10.1 Mechanical Strength Analysis; 5.10.2 Imbalanced Axial Force on the Stator; 5.11 Thermal Problems; Numerical Examples; 6 AFPM Machines Without Stator and Rotor Cores; 6.1 Advantages and Disadvantages; 6.2 Topology and Construction; 6.3 Air Gap Magnetic Flux Density; 6.4 Electromagnetic Torque and EMF; 6.5 Commercial Coreless AFPM Motors; 6.6 Case Study: Low-Speed AFPM Coreless Brushless Motor; 6.6.1 Performance Characteristics; 6.6.2 Cost Analysis; 6.6.3 Comparison With Cylindrical Motor With Laminated Stator and Rotor Cores; 6.7 Case Study: Low-Speed Coreless AFPM; Brushless Generator; 6.8 Characterist