Divided into five parts, this book is focused on ultra-capacitors and their applications in power conversion systems. It discusses ultra-capacitor analysis, modelling and module design from a macroscopic (application) perspective. It also describes power conversion applications, interface dc-dc converter design and entire conversion system design. It covers the background of energy storage technologies, as well as system design aspects in detail, and offers a case study of controlled electric drive applications.
Preface ix
1 Energy Storage Technologies and Devices 1
1.1 Introduction 1
1.1.1 Energy 1
1.1.2 Electrical Energy and its Role in Everyday Life 1
1.1.3 Energy Storage 2
1.2 Direct Electrical Energy Storage Devices 3
1.2.1 An Electric Capacitor as Energy Storage 3
1.2.2 An Inductor as Energy Storage 8
1.3 Indirect Electrical Energy Storage Technologies and Devices 11
1.3.1 Mechanical Energy Storage 11
1.3.2 Chemical Energy Storage 15
1.4 Applications and Comparison 19
References 21
2 Ultra-Capacitor Energy Storage Devices 22
2.1 Background of Ultra-Capacitors 22
2.1.1 Overview of Ultra-Capacitor Technologies 22
2.2 Electric Double-Layer Capacitors—EDLC 24
2.2.1 A Short History of the EDLC 24
2.2.2 The Ultra-Capacitor’s Structure 24
2.2.3 The Ultra-Capacitor’s Physical Model 24
2.3 The Ultra-Capacitor Macro (Electric Circuit) Model 27
2.3.1 Full Theoretical Model 27
2.3.2 A Simplified Model 36
2.3.3 A Simulation/Control Model 39
2.3.4 Exercises 41
2.4 The Ultra-Capacitor’s Energy and Power 42
2.4.1 The Ultra-Capacitor’s Energy and Specific Energy 42
2.4.2 The Ultra-Capacitor’s Energy Efficiency 43
2.4.3 The Ultra-Capacitor’s Specific Power 44
2.4.4 The Electrode Carbon Loading Limitation 45
2.4.5 Exercises 45
2.5 The Ultra-Capacitor’s Charge/Discharge Methods 47
2.5.1 Constant Resistive Loading 47
2.5.2 Constant Current Charging and Loading 47
2.5.3 Constant Power Charging and Loading 51
2.5.4 Exercises 57
2.6 Frequency Related Losses 59
2.6.1 The Current as a Periodic Function 60
2.6.2 The Current as a Nonperiodic Function 64
2.7 The Ultra-Capacitor’s Thermal Aspects 65
2.7.1 Heat Generation 65
2.7.2 Thermal Model 66
2.7.3 Temperature Rise 66
2.7.4 Exercises 69
2.8 Ultra-Capacitor High Power Modules 72
2.9 Ultra-Capacitor Trends and Future Development 74
2.9.1 The Requirements for Future Ultra-Capacitors 74
2.9.2 The Technology Directions 75
2.10 Summary 76
References 76
3 Power Conversion and Energy Storage Applications 78
3.1 Fundamentals of Static Power Converters 78
3.1.1 Switching-Mode Converters 78
3.1.2 Power Converter Classification 80
3.1.3 Some Examples of Voltage-Source Converters 80
3.1.4 Indirect Static AC–AC Power Converters 81
3.2 Interest in Power Conversion with Energy Storage 84
3.2.1 Definition of the Problem 84
3.2.2 The Solution 85
3.2.3 Which Energy Storage is the Right Choice? 86
3.2.4 Electrochemical Batteries versus Ultra-Capacitors 87
3.3 Controlled Electric Drive Applications 90
3.3.1 Controlled Electric Drives from Yesterday to Today 90
3.3.2 Application of Controlled Electric Drives 93
3.3.3 Definition of the Application Problems 93
3.3.4 The Solution 97
3.4 Renewable Energy Source Applications 102
3.4.1 Renewable Energy Sources 102
3.4.2 Definition of the Problem 107
3.4.3 Virtual Inertia and Renewable Energy ‘Generators’ 111
3.4.4 The Solution 113
3.5 Autonomous Power Generators and Applications 113
3.5.1 Applications 113
3.5.2 Definition of the Problem 118
3.5.3 The Solution 120
3.6 Energy Transmission and Distribution Applications 121
3.6.1 STATCOM Applications 121
3.6.2 Definition of the Problems 122
3.6.3 The Solution 126
3.7 Uninterruptible Power Supply (UPS) Applications 128
3.7.1 UPS System Applications 128
3.7.2 UPS with Ultra-Capacitor Energy Storage 130
3.8 Electric Traction Applications 131
3.8.1 Rail Vehicles 132
3.8.2 Road Vehicles 134
3.8.3 A Generalized Traction System 141
3.9 Summary 145
References 147
4 Ultra-Capacitor Module Selection and Design 149
4.1 Introduction 149
4.1.1 The Analysis and Design Objectives 149
4.1.2 Main Design Steps 150
4.1.3 The Ultra-Capacitor Model 151
4.2 The Module Voltage Rating and Voltage Level Selection 152
4.2.1 Relation between the Inner and Terminal Voltages 153
4.2.2 Maximum Operating Voltage 154
4.2.3 Minimum Operating Voltage 155
4.2.4 The Ultra-Capacitor Intermediate Voltage 156
4.2.5 The Ultra-Capacitor Rated Voltage 160
4.2.6 Exercises 162
4.3 The Capacitance Determination 164
4.3.1 Energy Storage/Recovery Capability 164
4.3.2 Conversion Efficiency 164
4.3.3 End-of-Life Effect on the Capacitance Selection 171
4.3.4 Exercises 172
4.4 Ultra-Capacitor Module Design 173
4.4.1 Series/Parallel Connection 173
4.4.2 Current Stress and Losses 176
4.4.3 String Voltage Balancing 178
4.4.4 Exercises 186
4.5 The Module’s Thermal Management 189
4.5.1 The Model’s Definition 190
4.5.2 Determination of the Model’s Parameters 192
4.5.3 The Model’s Parameters—Experimental Identification 193
4.5.4 The Cooling System Design 194
4.5.5 Exercises 197
4.6 Ultra-Capacitor Module Testing 207
4.6.1 Capacitance and Internal Resistance 208
4.6.2 Leakage Current and Self-Discharge 212
4.7 Summary 214
References 215
5 Interface DC–DC Converters 216
5.1 Introduction 216
5.2 Background and Classification of Interface DC–DC Converters 216
5.2.1 Voltage and Current Source DC–DC Converters 218
5.2.2 Full Power and Fractional Power Rated Interface
DC–DC Converters 220
5.2.3 Isolated and Non-Isolated Interface DC–DC Converters 220
5.2.4 Two-Level and Multi-Level Interface DC–DC Converters 222
5.2.5 Single-Cell and Multi-Cell Interleaved Interface
DC–DC Converters 222
5.3 State-of-the-Art Interface DC–DC Converters 223
5.3.1 Two-Level DC–DC Converters 223
5.3.2 Three-Level DC–DC Converters 225
5.3.3 Boost-Buck and Buck-Boost DC–DC Converters 226
5.3.4 Isolated DC–DC Converters 226
5.3.5 Application Summary 227
5.4 The Ultra-Capacitor’s Current and Voltage Definition 229
5.5 Multi-Cell Interleaved DC–DC Converters 231
5.5.1 Background of Interleaved DC–DC Converters 231
5.5.2 Analysis of a Two-Cell Interleaved Converter 233
5.5.3 N-Cell General Case Analysis 239
5.6 Design of a Two-Level N-Cell Interleaved DC–DC Converter 254
5.6.1 ICT Design: A Two-Cell Example 254
5.6.2 The Filter Inductor Design 261
5.6.3 DC Bus Capacitor Selection 268
5.6.4 Output Filter Capacitor Selection 274
5.6.5 Power Semiconductor Selection 277
5.6.6 Exercises 286
5.7 Conversion Power Losses: A General Case Analysis 295
5.7.1 The Origin of the Losses 295
5.7.2 Conduction Losses 297
5.7.3 Switching Losses 297
5.7.4 Blocking Losses 299
5.7.5 Definition of the Moving Average and RMS Value 299
5.8 Power Converter Thermal Management: A General Case Analysis 299
5.8.1 Why is Thermal Management Important? 299
5.8.2 Thermal Model of Power Semiconductors 300
5.8.3 Thermal Model of Magnetic Devices 306
5.8.4 Thermal Model of Power Electrolytic Capacitors 309
5.9 Summary 313
References 314
Index 317