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.