Shipboard propulsion, power electronics, and ocean energy

Shipboard Propulsion,

Power Electronics,

and Ocean Energy

Mukund R. Patel

K14071

Shipboard Propulsion, Power Electronics, and Ocean Energy fills the

need for a comprehensive book that covers modern shipboard propulsion

and the power electronics and ocean energy technologies that drive it.

With a breadth and depth not found in other books, it examines the power

electronics systems for ship propulsion and for extracting ocean energy,

which are mirror images of each other.

Comprised of sixteen chapters, the book is divided into four parts:

• Power Electronics and Motor Drives explains basic power

electronics converters and variable-frequency drives, cooling

methods, and quality of power

• Electric Propulsion Technologies focuses on the electric

propulsion of ships using recently developed permanent magnet

and superconducting motors, as well as hybrid propulsion using

fuel cell, photovoltaic, and wind power

• Renewable Ocean Energy Technologies explores renewable ocean

energy from waves, marine currents, and offshore wind farms

• System Integration Aspects discusses two aspects—energy

storage and system reliability—that are essential for any large-scale

power system

This timely book evolved from the author’s 30 years of work experience at

General Electric, Lockheed Martin, and Westinghouse Electric and 15 years

of teaching at the U.S. Merchant Marine Academy.

As a textbook, it is ideal for an elective course at marine and naval

academies with engineering programs. It is also a valuable reference for

commercial and military shipbuilders, port operators, renewable ocean

energy developers, classification societies, machinery and equipment

manufacturers, researchers, and others interested in modern shipboard

power and propulsion systems.

Naval Science & Navigation

Shipboard Propulsion,

Power Electronics,

and Ocean Energy

K14071_Cover_mech.indd 1 1/17/12 11:21 AM

Shipboard Propulsion,

Power Electronics,

and Ocean Energy

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CRC Press is an imprint of the

Taylor & Francis Group, an informa business

Boca Raton London New York

Shipboard Propulsion,

Power Electronics,

and Ocean Energy

Mukund R. Patel

Cover illustration courtesy of Azipod® Propulsion System (With permission from ABB Marine.).

CRC Press

Taylor & Francis Group

6000 Broken Sound Parkway NW, Suite 300

Boca Raton, FL 33487-2742

© 2012 by Taylor & Francis Group, LLC

CRC Press is an imprint of Taylor & Francis Group, an Informa business

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Version Date: 20120106

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To Anthony, Patricia, and Malena

for enhancing our family

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vii

Contents

Preface.................................................................................................................... xiii

Acknowledgments....................................................................................................xv

About the Author ...................................................................................................xvii

About This Book.....................................................................................................xix

Systems of Units and Conversion Factors...............................................................xxi

Part A Power Electronics and Motor Drives

Chapter 1 Power Electronics Devices...................................................................3

1.1 Diode .........................................................................................7

1.2 Thyristor.................................................................................. 12

1.3 Power Transistor...................................................................... 14

1.4 Hybrid Devices........................................................................ 16

1.5 Di/Dt and Dv/Dt Snubber Circuits.......................................... 17

1.6 Switching Power Loss ............................................................. 21

1.7 Device Application Trends......................................................24

1.8 Device Cooling and Rerating ..................................................25

Problems.............................................................................................26

Questions............................................................................................27

Further Reading .................................................................................27

Chapter 2 DC-DC Converters.............................................................................29

2.1 Buck Converter........................................................................29

2.2 Boost Converter.......................................................................36

2.3 Buck-Boost Converter..............................................................38

2.4 Flyback Converter (Buck or Boost).........................................38

2.5 Transformer-Coupled Forward Converter...............................40

2.6 Push-Pull Converter ................................................................ 41

2.7 Inductor-Coupled Buck Converter........................................... 41

2.8 Duty Ratio Control Circuit...................................................... 42

2.9 Load Power Converter............................................................. 42

2.10 Power Supply ...........................................................................44

Problems.............................................................................................46

Questions............................................................................................ 47

Further Reading ................................................................................. 47

viii Contents

Chapter 3 AC-DC-AC Converters.......................................................................49

3.1 AC-DC Rectifier......................................................................49

3.2 AC-AC Voltage Converter....................................................... 62

3.3 DC-AC Inverter .......................................................................64

3.4 Frequency Converter ............................................................... 74

3.5 Thyristor Turnoff (Commutation) Circuits..............................79

3.6 Other Power Electronics Applications .................................... 81

3.7 Common Converter Terms......................................................83

3.8 Notes on Converter Design......................................................84

Problems.............................................................................................87

Questions............................................................................................88

Further Reading .................................................................................89

Chapter 4 Variable-Frequency Drives ................................................................ 91

4.1 Pump Performance Characteristics.........................................92

4.2 Pump Energy Savings with VFD ............................................94

4.3 Shipboard Use of VFDs ..........................................................98

4.4 VFD for Medium-Size Motor..................................................98

4.5 Constant V/f Ratio Operation ................................................ 101

4.6 Commutation and Control Methods...................................... 107

4.7 Open-Loop Control System................................................... 109

4.8 Vector Control Drives............................................................ 109

4.9 Propulsion with a Twelve-Pulse VFD ................................... 111

4.10 Special VFD Cables.............................................................. 111

4.11 Variable-Voltage DC Motor Drive......................................... 114

4.12 Variable-Speed Drive in Metro Trains.................................. 116

4.13 VFD as Large-Motor Starter................................................. 117

4.14 Converter Topologies Compared........................................... 118

4.15 Notes on VFDs...................................................................... 119

Problems........................................................................................... 121

Questions.......................................................................................... 122

Further Reading ............................................................................... 122

Chapter 5 Quality of Power .............................................................................. 123

5.1 Power Quality Terminology .................................................. 123

5.2 Electrical Bus Model............................................................. 125

5.3 Harmonics .............................................................................128

5.4 Power Quality Studies........................................................... 140

5.5 Harmonic Reduction.............................................................. 141

5.6 Ieee Standard 519 ................................................................ 151

5.7 International Standards ......................................................... 153

Problems........................................................................................... 153

Questions.......................................................................................... 155

Further Reading ............................................................................... 156

Contents ix

Chapter 6 Power Converter Cooling ................................................................. 157

6.1 Heat Transfer by Conduction................................................. 157

6.2 Multiple Conduction Paths.................................................... 159

6.3 Convection and Radiation ..................................................... 162

6.4 Thermal Transient ................................................................. 164

6.5 Water Cooling........................................................................ 165

Problems........................................................................................... 173

Questions.......................................................................................... 174

Further Reading ............................................................................... 175

Part B Electric Propulsion Technologies

Chapter 7 Electric Propulsion Systems............................................................. 179

7.1 Current Status of Electric Propulsion.................................... 180

7.2 Integrated Electric Propulsion............................................... 185

7.3 Azimuth Z Drive ................................................................... 186

7.4 Azimuth Pod Drive................................................................ 187

7.5 Advantages of Electric Propulsion ........................................ 189

7.6 Electric Propulsion Architecture........................................... 194

7.7 Motor Drives and Speed Control........................................... 197

7.8 Power Electronics Converters for Vfd................................. 198

7.9 Propulsion Power Requirement .............................................203

Questions..........................................................................................207

Further Reading ...............................................................................207

Chapter 8 Propulsion Motors............................................................................209

8.1 Synchronous Motor ............................................................... 210

8.2 Induction Motor..................................................................... 211

8.3 Permanent Magnet Motor...................................................... 212

8.4 Superconducting Synchronous Motor ................................... 214

8.5 Superconducting Homopolar Motor...................................... 217

8.6 Other Motor Types ................................................................ 221

8.7 Other Components.................................................................223

8.8 Notes on Propulsion Motors..................................................223

Questions..........................................................................................224

Further Reading ...............................................................................224

Chapter 9 Superconductors in Navy Ships........................................................225

9.1 Superconductivity..................................................................225

9.2 Degaussing Coil.....................................................................226

9.3 Synchronous Machines..........................................................229

9.4 Superconducting Energy Storage .......................................... 231

x Contents

9.5 Industry Applications............................................................234

9.6 Research Applications........................................................... 235

9.7 Critical B, J, T of the Superconductor................................... 237

9.8 Coil Design and Cooling ....................................................... 239

Questions.......................................................................................... 241

Further Reading ............................................................................... 241

Chapter 10 Fuel Cell Power ................................................................................243

10.1 Electrochemistry ...................................................................244

10.2 Electrical Performance..........................................................247

10.3 Common Fuel Cell Types......................................................250

10.4 Present and Future Use.......................................................... 252

10.5 Present Development Issues .................................................. 257

Questions..........................................................................................258

Further Reading ...............................................................................258

Chapter 11 Hybrid Propulsion ............................................................................ 261

11.1 Environmental Regulations................................................... 261

11.2 Hybrid Tugboat...................................................................... 262

11.3 Hybrid Ferry..........................................................................264

11.4 Hybrid Automobile................................................................ 267

11.5 Magnetohydrodynamics Propulsion in Ships........................268

Questions.......................................................................................... 271

Further Reading ............................................................................... 271

Part C Emerging Ocean Energy Technologies

Chapter 12 Ocean Wave Power........................................................................... 275

12.1 Wave Power Estimate ............................................................ 275

12.2 Power Generation Schemes................................................... 278

Questions..........................................................................................286

Further Reading ...............................................................................286

Chapter 13 Marine Current Power......................................................................287

13.1 Speed and Power Relations ...................................................288

13.2 Present Developments ...........................................................295

Questions..........................................................................................298

Further Reading ...............................................................................298

Chapter 14 Offshore Wind Power.......................................................................299

14.1 Wind Power Theory ..............................................................300

14.2 Offshore Advantages.............................................................304

Contents xi

14.3 Power Transmission to Shore ................................................304

14.4 Ac versus Dc Cable..............................................................306

14.5 Offshore Foundations............................................................308

14.6 Farshore Foundations ............................................................ 312

14.7 Installations and Maintenance............................................... 313

14.8 Forces on Structure................................................................ 315

14.9 Materials and Corrosion........................................................ 315

14.10 Offshore Wind Power Trends................................................ 317

14.11 Environmental Regulations................................................... 319

14.12 International Safety Regulation............................................. 319

Questions..........................................................................................320

Further Reading ............................................................................... 321

Part D System Integration Aspects

Chapter 15 Large-Scale Energy Storage............................................................. 325

15.1 Electrochemical Battery........................................................ 325

15.2 Supercapacitor .......................................................................326

15.3 Rotating Flywheel ................................................................. 328

15.4 Superconducting Coil ............................................................ 333

15.5 Compressed Air..................................................................... 334

Questions.......................................................................................... 336

Further Reading ............................................................................... 336

Chapter 16 System Reliability Fundamentals..................................................... 337

16.1 Failure Mechanisms .............................................................. 337

16.2 Aging of Power Electronics Devices..................................... 338

16.3 Failure Rate in Time.............................................................. 338

16.4 Random Failures.................................................................... 339

16.5 Fundamental Theorems of Reliability................................... 341

16.6 Series-Parallel Reliability...................................................... 341

16.7 Redundancies.........................................................................344

16.8 Failure Rate Statistics............................................................346

16.9 Mil-Hdbk-217......................................................................... 347

16.10 Part Count Method of Reliability Estimate...........................348

16.11 Derating for Reliability..........................................................349

16.12 Quick Estimate of Failure Rate .............................................349

16.13 Failure Modes, Effects, and Criticality Analysis.................. 350

Questions.......................................................................................... 350

Further Reading ............................................................................... 350

Index ...................................................................................................................... 351

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xiii

Preface

The marine industry demand for larger cargo and cruise ships with higher speed,

lower life-cycle cost, lower environmental impact, and greater maneuverability, reli￾ability, and safety has been rapidly growing. The conventional ship today can deliver

transatlantic cargo in 2 to 3 weeks. Fast cargo ships being designed today would

deliver the same freight in a week at about one-fifth the cost of airfreight. Moreover,

high emissions from the land and air transportation on congested routes are now

favoring marine transportation, which is mostly away from the population. Among

large passenger cruise ships built today, the 339-m long, 38.6-m wide Freedom-class

cruise of the Royal Caribbean International takes 4375 passengers and 1365 crew

members with a diesel-electric power plant approaching 100 MWe rating that com￾pares in size with some small power plants on land.

No other technology than power electronics has brought a greater change in

the electrical power industry—on ship or on land—and still holds the potential to

bring future improvements. The power electronics equipment prices have declined

to approximately one-tenth in cost since the 1990s, fueling rapid growth in their

applications throughout the power industry. Most cruise ships and many icebreak￾ers today use electric propulsion, which uses power electronics in abundance. The

navies of the world have undertaken electric propulsion with power electronics as

their next goal for numerous benefits it offers.

Shipbuilders around the world have added requirements to minimize noise and

vibration and maximize usable space. This allows larger combat weapons in navy

warships and more paying passengers in passenger cruise ships, where the premium

on space is the greatest. The integrated electrical power system makes the navy ship

reconfigurable for greater survivability. The Office of Naval Research has been pro￾viding research funding for developing electric propulsion with an integrated elec￾trical power system. The research is conducted by the Electric Ship Research and

Development Consortium, which includes Florida State University, Massachusetts

Institute of Technology, Mississippi State University, Purdue University, the U.S.

Naval Academy, University of South Carolina, and the University of Texas–Austin.

For these reasons, shipboard power systems have undergone significant new

developments since 2000 and will continue to do so at an even faster rate in the

current decade. Today’s shipbuilders of both commercial and navy ships, along with

their support industries, are now taking an active part in research and development to

advance shipboard electric propulsion and power electronics systems, both of which

are covered at length in this book.

New high-power density permanent magnet and superconducting motors devel￾oped to fit the confines of propulsion pods are discussed in this book. Potential appli￾cations of the recently developed high-temperature superconductors in degaussing the

ship and in energy storage to provide pulse power on combat ships are also discussed.

It is in this light that modern commercial and military shipbuilders are looking

for electrical power and power electronics engineers to meet their rapidly growing

xiv Preface

need for large, fast, efficient, reconfigurable, and economical ships to compete in

the growing international trade and national defense. Until now, there was no single

book available that covered the entire scope of shipboard power and propulsion sys￾tems. The industry professionals had been relying on limited publications presented

at various conferences and a few books with short sections with sketchy coverage of

this vast subject.

This book is a companion to Shipboard Electrical Power Systems by the same

author published by CRC Press in 2011. It is the first comprehensive volume of its

kind that focuses on the shipboard electric propulsion and power electronics systems,

in addition to the renewable ocean energy technologies, in which marine engineers

will gradually become involved. As such, the electrical power system for extracting

ocean energy is the exact reverse of the variable-frequency motor drive already in

wide use for ship propulsion.

It is hoped that this book is a timely addition to the literature and a one-volume

resource for students at various marine and naval academies around the world and a

range of industry professionals.

Mukund R. Patel

Kings Point, New York