2nd Edition

Variable Speed Generators

By Ion Boldea Copyright 2016
    600 Pages 456 B/W Illustrations
    by CRC Press

    Variable Speed Generators, the second of two volumes in the Electric Generators Handbook, provides extensive coverage of variable speed generators in distributed generation and renewable energy applications around the world. The book delves into the steady state, transients, control, and design of claw-pole-rotor synchronous, induction, permanent-magnet-(PM)-assisted synchronous, and switched reluctance starter alternators for electric hybrid vehicles. It discusses PM synchronous, transverse flux PM, and flux reversal PM generators for low-speed wind and hydro energy conversion. It also explores linear motion alternators for residential and spacecraft applications. Numerous design and control examples illustrate the exposition.

    Fully revised and updated to reflect the last decade’s worth of progress in the field, this Second Edition adds new sections that:

    • Address the ride-through control of doubly fed induction generators under unbalanced voltage sags
    • Consider the control of stand-alone doubly fed induction generators under unbalanced nonlinear loads
    • Detail a stand-alone squirrel cage induction generator (SCIG) with AC output and a low-rating pulse-width modulated (PWM) converter
    • Present a twin stator winding SCIG with 50 percent rating inverter and diode rectifier, and a dual stator winding induction generator with nested cage rotor
    • Examine interior permanent magnet claw-pole-alternator systems for more vehicle braking energy recuperation, and high power factor Vernier PM generators
    • Depict a PM-assisted reluctance synchronous motor/generator for an electric hybrid vehicle, and a double stator switched reluctance generator with segmented rotor
    • Describe the grid to stand-alone transition motion-sensorless dual-inverter control of permanent magnet synchronous generators with asymmetrical grid voltage sags and harmonics filtering

    The promise of renewable, sustainable energy rests on our ability to design innovative power systems that are able to harness energy from a variety of sources. Variable Speed Generators, Second Edition supplies state-of-the-art tools necessary to design, validate, and deploy the right power generation technologies to fulfill tomorrow's complex energy needs.

    Wound-Rotor Induction Generators: Steady State
    Introduction
    Construction Elements
    Steady-State Equations
    Equivalent Circuit
    Phasor Diagrams
    Operation at the Power Grid
    Autonomous Operation of WRIGs
    Operation of WRIGs in the Brushless Exciter Mode
    Losses and Efficiency of WRIGs
    Summary
    References

    Wound-Rotor Induction Generators: Transients and Control
    Introduction
    WRIG Phase Coordinate Model
    Space-Phasor Model of WRIG
    Space-Phasor Equivalent Circuits and Diagrams
    Approaches to WRIG Transients
    Static Power Converters for WRIGs
    Vector Control of WRIG at Power Grid
    Direct Power Control of WRIG at Power Grid
    Independent Vector Control of Positive and Negative Sequence Currents
    Motion-Sensorless Control
    Vector Control in Stand-Alone Operation
    Self-Starting, Synchronization, and Loading at the Power Grid
    Voltage and Current Low-Frequency Harmonics of WRIG
    Ride-Through Control of DFIG under Unbalanced Voltage Sags
    Stand-Alone DFIG Control under Unbalanced Nonlinear Loads
    Summary
    References

    Wound-Rotor Induction Generators: Design and Testing
    Introduction
    Design Specifications: An Example
    Stator Design
    Rotor Design
    Magnetization Current
    Reactances and Resistances
    Electrical Losses and Efficiency
    Testing of WRIGs
    Summary
    References

    Self-Excited Induction Generators
    Introduction
    Principle of Cage-Rotor Induction Machine
    Self-Excitation: A Qualitative View
    Steady-State Performance of Three-Phase SEIGs
    Performance Sensitivity Analysis
    Pole Changing SEIGs for Variable Speed Operation
    Unbalanced Operation of Three-Phase SEIGs
    One Phase Open at Power Grid
    Three-Phase SEIG with Single-Phase Output
    Two-Phase SEIGs with Single-Phase Output
    Three-Phase SEIG Transients
    Parallel Connection of SEIGs
    Direct Connection to Grid Transients in Cage-Rotor Induction Generators
    More on Power Grid Disturbance Transients in Cage-Rotor Induction Generators
    Summary
    References

    Stator-Converter-Controlled Induction Generators
    Introduction
    Grid-Connected SCIGs: The Control System
    Grid Connection and Four-Quadrant Operation of SCIGs
    Stand-Alone Operation of SCIG
    Parallel Operation of SCIGs
    Static Capacitor Exciter Stand-Alone IG for Pumping Systems
    Operation of SCIGs with DC Voltage-Controlled Output
    Stand-Alone SCIG with AC Output and Low Rating PWM Converter
    Dual Stator Winding for Grid Applications
    Twin Stator Winding SCIG with 50% Rating Inverter and Diode Rectifier
    Dual Stator Winding IG with Nested Cage Rotor
    Summary
    References

    Automotive Claw-Pole-Rotor Generator Systems
    Introduction
    Construction and Principle
    Magnetic Equivalent Circuit Modeling
    Three-Dimensional Finite Element Method Modeling
    Losses, Efficiency, and Power Factor
    Design Improvement Steps
    Lundell Starter/Generator for Hybrid Vehicles
    IPM Claw-Pole Alternator System for More Vehicle Braking Energy Recuperation: A Case Study
    Summary
    References

    Induction Starter/Alternators for Electric Hybrid Vehicles
    Electric Hybrid Vehicle Configuration
    Essential Specifications
    Topology Aspects of Induction Starter/Alternator
    ISA Space-Phasor Model and Characteristics
    Vector Control of ISA
    DTFC of ISA
    ISA Design Issues for Variable Speed
    Summary
    References

    Permanent-Magnet-Assisted Reluctance Synchronous Starter/Alternators for Electric Hybrid Vehicles
    Introduction
    Topologies of PM-RSM
    Finite Element Analysis
    dq Model of PM-RSM
    Steady-State Operation at No Load and Symmetric Short Circuit
    Design Aspects for Wide Speed Range Constant Power Operation
    Power Electronics for PM-RSM for Automotive Applications
    Control of PM-RSM for EHV
    State Observers without Signal Injection for Motion Sensorless Control
    Signal Injection Rotor Position Observers
    Initial and Low-Speed Rotor Position Tracking
    50/100 kW, 1350–7000 rpm (600 Nm Peak Torque, 40 kg) PM-Assisted Reluctance Synchronous Motor/Generator for HEV: A Case Study
    Summary
    References

    Switched Reluctance Generators and Their Control
    Introduction
    Practical Topologies and Principles of Operation
    SRG(M) Modeling
    Flux/Current/Position Curves
    Design Issues
    PWM Converters for SRGs
    Control of SRG(M)s
    Direct Torque Control of SRG(M)
    Rotor Position and Speed Observers for Motion-Sensorless Control
    Output Voltage Control in SRG
    Double Stator SRG with Segmented Rotor
    Summary
    References

    Permanent Magnet Synchronous Generator Systems
    Introduction
    Practical Configurations and Their Characterization
    Air Gap Field Distribution, emf, and Torque
    Stator Core Loss Modeling
    Circuit Model
    Circuit Model of PMSG with Shunt Capacitors and AC Load
    Circuit Model of PMSG with Diode Rectifier Load
    Utilization of Third Harmonic for PMSG with Diode Rectifiers
    Autonomous PMSGs with Controlled Constant Speed and AC Load
    Grid-Connected Variable-Speed PMSG System
    PM Genset with Multiple Outputs
    Super-High-Speed PM Generators: Design Issues
    Super-High-Speed PM Generators: Power Electronics Control Issues
    Design of a 42 Vdc Battery-Controlled-Output PMSG System
    Methods for Testing PMSGs
    Grid to Stand-Alone Transition Motion-Sensorless Dual-Inverter Control of PMSG with Asymmetrical Grid Voltage Sags and Harmonics Filtering: A Case Study
    Note on Medium-Power Vehicular Electric Generator Systems
    Summary
    References

    Transverse Flux and Flux Reversal Permanent Magnet Generator Systems
    Introduction
    Three-Phase Transverse Flux Machine: Magnetic Circuit Design
    TFM: The dq Model and Steady State
    Three-Phase FR-PM Generator: Magnetic and Electric Circuit Design
    High Power Factor Vernier PM Generators
    Summary
    References

    Linear Motion Alternators
    Introduction
    LMA Principle of Operation
    PM-LMA with Coil Mover
    Multipole LMA with Coil Plus Iron Mover
    PM-Mover LMAs
    Tubular Homopolar PM Mover Single-Coil LMA
    Flux Reversal LMA with Mover PM Flux Concentration
    PM-LMAs with Iron Mover
    Flux Reversal PM-LMA Tubular Configuration
    Control of PM-LMAs
    Progressive-Motion LMAs for Maglevs with Active Guideway
    Summary
    References

    Biography

    Ion Boldea is a professor of electrical engineering at the University Politehnica Timişoara, Romania. A life fellow of the Institute of Electrical and Electronics Engineers (IEEE), Professor Boldea has worked, published, lectured, and consulted extensively on the theory, design, and control of linear and rotary electric motors and generators for more than 40 years.