Variable Speed Generators

Chapter 1: Wound Rotor Induction Generators (WRIGs): Steady State
 1.1 Introduction
 1.2 Construction Elements
  1.2.1 Magnetic Cores
  1.2.2 Windings and Their mmfs
  1.2.3 Slip-Rings and Brushes
 1.3 Steady-State Equations
 1.4 Equivalent Circuit
 1.5 Phasor Diagrams
 1.6 Operation at the Power Grid
  1.6.1 Stator Power vs. Power Angle
  1.6.2 Rotor Power vs. Power Angle
  1.6.3 Operation at Zero Slip (S = 0)
 1.7 Autonomous Operation of WRIG
 1.8 Operation of WRIG in the Brushless Exciter Mode
 1.9 Losses and Efficiency of WRIG

Chapter 2: Wound Rotor Induction Generators: Transients and Control
 2.1 Introduction
 2.2 The WRIG Phase Coordinate Model
 2.3 The Space-Phasor Model of WRIG
 2.4 Space-Phasor Equivalent Circuits and Diagrams
 2.5 Approaches to WRIG Transients
 2.6 Static Power Converters for WRIGs
  2.6.1 Direct AC–AC Converters
  2.6.2 DC Voltage Link AC–AC Converters
 2.7 Vector Control of WRIG at Power Grid
  2.7.1 Principles of Vector Control of Machine (Rotor)-Side Converter
  2.7.2 Vector Control of Source-Side Converter
  2.7.3 Wind Power WRIG Vector Control at the Power Grid
   2.7.3.1 The Wind Turbine Model
   2.7.3.2 The Supply-Side Converter Model
   2.7.3.3 The Generator-Side Converter Model
   2.7.3.4 Simulation Results
   2.7.3.5 Three-Phase Short-Circuit on the Power Grid
   2.7.3.6 Mechanism to Improve the Performance during Fault
 2.8 Direct Power Control (DPC) of WRIG at Power Grid
  2.8.1 The Concept of DPC
 2.9 Independent Vector Control of Positive and Negative Sequence Currents
 2.10 Motion-Sensorless Control
 2.11 Vector Control in Stand-Alone Operation
 2.12 Self-Starting, Synchronization, and Loading at the Power Grid
 2.13 Voltage and Current Low-Frequency Harmonics of WRIG

Chapter 3: Wound Rotor Induction Generators (WRIGs): Design and Testing
 3.1 Introduction
 3.2 Design Specifications — An Example
 3.3 Stator Design
 3.4 Rotor Design
 3.5 Magnetization Current
 3.6 Reactances and Resistances
 3.7 Electrical Losses and Efficiency
 3.8 Testing of WRIGs

Chapter 4: Self-Excited Induction Generators
 4.1 Introduction
 4.2 The Cage Rotor Induction Machine Principle
 4.3 Self-Excitation: A Qualitative View
 4.4 Steady-State Performance of Three-Phase SEIGs
  4.4.1 Second-Order Slip Equation Methods
  4.4.2 SEIGs with Series Capacitance Compensation
 4.5 Performance Sensitivity Analysis
  4.5.1 For Constant Speed
  4.5.2 For Unregulated Prime Movers
 4.6 Pole Changing SEIGs for Variable Speed Operation
 4.7 Unbalanced Operation of Three-Phase SEIGs
 4.8 One Phase Open at Power Grid
 4.9 Three-Phase SEIG with Single-Phase Output
 4.10 Two-Phase SEIGs with Single-Phase Output
 4.11 Three-Phase SEIG Transients
 4.12 Parallel Connection of SEIGs
 4.13 Connection Transients in Cage Rotor Induction Generators at Power Grid
 4.14 More on Power Grid Disturbance Transients in Cage Rotor Induction Generators

Chapter 5: Stator Converter Controlled Induction Generators (SCIGs)
 5.1 Introduction
 5.2 Grid Connected SCIGs: The Control System
  5.2.1 The Machine-Side PWM Converter Control
   5.2.1.1 State Observers for DTFC of SCIGs
   5.2.1.2 The DTFC–SVM Block
  5.2.2 Grid-Side Converter Control
 5.3 Grid Connection and Four-Quadrant Operation of SCIGs
 5.4 Stand-Alone Operation of SCIG
 5.5 Parallel Operation of SCIGs
 5.6 Static Capacitor Exciter Stand-Alone IG for Pumping Systems
 5.7 Operation of SCIGs with DC Voltage Controlled Output
 5.8 Dual Stator Winding for Grid Applications

Chapter 6: Automotive Claw-Pole-Rotor Generator Systems
 6.1 Introduction
 6.2 Construction and Principle
 6.3 Magnetic Equivalent Circuit (MEC) Modeling
 6.4 Three-Dimensional Finite Element Method (3D FEM) Modeling
 6.5 Losses, Efficiency, and Power Factor
 6.6 Design Improvement Steps
  6.6.1 Claw-Pole Geometry
  6.6.2 Booster Diode Effects
  6.6.3 Assisting Permanent Magnets
  6.6.4 Increasing the Number of Poles
  6.6.5 Winding Tapping (Reconfiguration)
  6.6.6 Claw-Pole Damper
  6.6.7 The Controlled Rectifier
 6.7 The Lundell Starter/Generator for Hybrid Vehicles

Chapter 7: Induction Starter/Alternators (ISAs) for Electric Hybrid Vehicles (EHVs)
 7.1 EHV Configuration
 7.2 Essential Specifications
  7.2.1 Peak Torque (Motoring) and Power (Generating)
  7.2.2 Battery Parameters and Characteristics
 7.3 Topology Aspects of Induction Starter/Alternator (ISA)
 7.4 ISA Space-Phasor Model and Characteristics
 7.5 Vector Control of ISA
 7.6 DTFC of ISA
 7.7 ISA Design Issues for Variable Speed
  7.7.1 Power and Voltage Derating
  7.7.2 Increasing Efficiency
  7.7.3 Increasing the Breakdown Torque
  7.7.4 Additional Measures for Wide Constant Power Range
   7.7.4.1 Winding Reconfiguration

Chapter 8: Permanent-Magnet-Assisted Reluctance Synchronous Starter/Alternators for Electric Hybrid Vehicles
 8.1 Introduction
 8.2 Topologies of PM-RSM
 8.3 Finite Element Analysis
  8.3.1 Flux Distribution
  8.3.2 The d–q Inductances
  8.3.3 The Cogging Torque
  8.3.4 Core Losses Computation by FEM
 8.4 The d–q Model of PM-RSM
 8.5 Steady-State Operation at No Load and Symmetric Short-Circuit
  8.5.1 Generator No-Load
  8.5.2 Symmetrical Short-Circuit
 8.6 Design Aspects for Wide Speed Range Constant Power Operation
 8.7 Power Electronics for PM-RSM for Automotive Applications
 8.8 Control of PM-RSM for EHV
 8.9 State Observers without Signal Injection for Motion Sensorless Control
 8.10 Signal Injection Rotor Position Observers
 8.11 Initial and Low Speed Rotor Position Tracking

Chapter 9: Switched Reluctance Generators and Their Control
 9.1 Introduction
 9.2 Practical Topologies and Principles of Operation
  9.2.1 The kW/Peak kVA Ratio
 9.3 SRG(M) Modeling
 9.4 The Flux/Current/Position Curves
 9.5 Design Issues
  9.5.1 Motor and Generator Specifications
  9.5.2 Number of Phases, Stator and Rotor Poles: m, Ns, Nr
  9.5.3 Stator Bore Diameter Dis and Stack Length
  9.5.4 The Number of Turns per Coil Wc for Motoring
  9.5.5 Current Waveforms for Generator Mode
 9.6 PWM Converters for SRGs
 9.7 Control of SRG(M)s
  9.7.1 Feed-Forward Torque Control of SRG(M) with Position Feedback
 9.8 Direct Torque Control of SRG(M)
 9.9 Rotor Position and Speed Observers for Motion-Sensorless Control
  9.9.1 Signal Injection for Standstill Position Estimation
 9.10 Output Voltage Control in SRG

Chapter 10: Permanent Magnet Synchronous Generator Systems
 10.1 Introduction
 10.2 Practical Configurations and Their Characterization
  10.2.1 Distributed vs. Concentrated Windings
 10.3 Airgap Field Distribution, emf and Torque
 10.4 Stator Core Loss Modeling
  10.4.1 FEM-Derived Core Loss Formulas
  10.4.2 Simplified Analytical Core Loss Formulas
 10.5 The Circuit Model
  10.5.1 The Phase Coordinate Model
  10.5.2 The d–q Model of PMSG
 10.6 Circuit Model of PMSG with Shunt Capacitors and AC Load
 10.7 Circuit Model of PMSG with Diode Rectifier Load
 10.8 Utilization of Third Harmonic for PMSG with Diode Rectifiers
 10.9 Autonomous PMSGs with Controlled Constant Speed and AC Load
 10.10 Grid-Connected Variable-Speed PMSG System
  10.10.1 The Diode Rectifier and Boost DC–DC Converter Case
 10.11 The PM Genset with Multiple Outputs
 10.12 Super-High-Speed PM Generators: Design Issues
  10.12.1 Rotor Sizing
  10.12.2 Stator Sizing
  10.12.3 The Losses
 10.13 Super-High-Speed PM Generators: Power Electronics Control Issues
 10.14 Design of a 42 Vdc Battery-Controlled-Output PMSG System
  10.14.1 Design Initial Data
  10.14.2 The Minimum Speed: nmin
  10.14.3 The Number of Poles: 2p1
  10.14.4 The Rotor Configuration
  10.14.5 The Stator Winding Type
  10.14.6 Winding Tapping
  10.14.7 The PMSG Current Waveform
  10.14.8 The Diode Rectifier Imposes almost Unity Power Factor
  10.14.9 Peak Torque-Based Sizing
  10.14.10 Generator to DC Voltage Relationships
  10.14.11 The PM, Ls, Rs Expressions
 10.15 Methods for Testing PMSGs
  10.15.1 Standstill Tests
  10.15.2 No-Load Generator Tests
  10.15.3 Short-Circuit Generator Tests
  10.15.4 Stator Leakage Inductance and Skin Effect
  10.15.5 The Motor No-Load Test
  10.15.6 The Generator Load Tests
 10.16 Note on Medium-Power Vehicular Electric Generator Systems

Chapter 11: Transverse Flux and Flux Reversal Permanent Magnet Generator Systems
 11.1 Introduction
 11.2 The Three-Phase Transverse Flux Machine (TFM): Magnetic Circuit Design
  11.2.1 The Phase Inductance Ls
  11.2.2 Phase Resistance and Slot Area
 11.3 TFM — the d–q Model and Steady State
 11.4 The Three-Phase Flux Reversal Permanent Magnet Generator: Magnetic and Electric Circuit Design
  11.4.1 Preliminary Geometry for 200 Nm at 128 rpm via Conceptual Design
  11.4.2 FEM Analysis of Pole-PM FRM at No Load
  11.4.3 FEM Analysis at Steady State on Load
  11.4.4 FEM Computation of Inductances
  11.4.5 Inductances and the Circuit Model of FRM
  11.4.6 The d–q Model of FRM
  11.4.7 Notes on Flux Reversal Generator (FRG) Control

Chapter 12: Linear Motion Alternators (LMAs)
 12.1 Introduction
 12.2 LMA Principle of Operation
  12.2.1 The Motion Equation
 12.3 PM-LMA with Coil Mover
 12.4 Multipole LMA with Coil Plus Iron Mover
 12.5 PM-Mover LMAs
 12.6 The Tubular Homopolar PM Mover Single-Coil LMA
 12.7 The Flux Reversal LMA with Mover PM Flux Concentration
 12.8 PM-LMAs with Iron Mover
 12.9 The Flux Reversal PM-LMA Tubular Configuration
  12.9.1 The Analytical Model
 12.10 Control of PM-LMAs
  12.10.1 Electrical Control
  12.10.2 The Spark-Ignited Gasoline Linear Engine Model
  12.10.3 Note on Stirling Engine LMA Stability
 12.11 Progressive-Motion LMAs for Maglevs with Active Guideway
  12.11.1 Note on Magnetohydrodynamic (MHD) Linear Generators