Smart Hybrid AC/DC Microgrids

Yunwei Ryan Li, Ph.D., is a Professor at the University of Alberta, Canada. His research interests include distributed generation, microgrids, renewable energy, smart grids, high power converters, and electric motor drives. Dr. Li is a Fellow of IEEE and is recognized as a Highly Cited Researcher by the Web of Science Group. He serves as the Editor-in-Chief for IEEE Transactions on Power Electronics (TPEL) Letters. Farzam Nejabatkhah, Ph.D., is a Senior Research and Development (R&D) Engineer at CYME International T&D, Eaton. His research interests include smart grids, hybrid AC/DC microgrids, power converters, and cyber-physical systems. Hao Tian, Ph.D., is a Postdoctoral Research Fellow at the University of Alberta, Canada. His research interests include microgrids and high-power converters.

• Author Biographies xiiiPreface xvPart I Smart Hybrid AC/DC Microgrids 11 Smart Hybrid AC/DC Microgrids 31.1 Introduction to Microgrids 31.1.1 Concept of Microgrids 31.1.2 Development of Microgrids 41.1.3 Features of Modern Microgrids 61.2 Smart Hybrid Microgrid Configurations 81.2.1 AC-coupled Hybrid Microgrid 81.2.2 DC-coupled Hybrid Microgrid 91.2.3 AC/DC-Coupled Hybrid Microgrid 101.2.4 Examples of Hybrid Microgrids 111.3 Smart Hybrid Microgrid Operations 141.3.1 Distributed Generation and Energy Storage Systems 141.3.2 Smart Interfacing Converters 161.3.3 Cyber Systems 161.3.4 Power Management and Energy Management Systems 171.3.5 Power Quality 171.4 Outline of the Book 18References 202 Renewable Energy, Energy Storage, and Smart Interfacing Power Converters 212.1 Renewable-based Generation 212.1.1 Photovoltaic (PV) Power Systems 212.1.2 Wind Power Systems 292.2 Energy Storage Systems 372.2.1 Battery Energy Storage System 382.2.2 Flywheel Energy Storage System 432.2.3 Superconducting Magnet Energy Storage System 442.2.4 Hydrogen and Fuel Cell Energy Storage 452.3 Integration of Renewable Energy and Energy Storage 492.3.1 Structure of Smart Interfacing Converters (IFCs) 492.3.2 Operation and Coordination 522.4 Summary 54References 543 Smart Microgrid Communications 553.1 Introduction 553.2 Communication Technique for Smart Microgrids 573.2.1 Basic Concepts of Communication Systems 573.2.2 Structures of Communication Networks in Smart Microgrids 593.2.3 Requirements of Communication in Smart Microgrids 613.2.4 Wired Communication Technologies in a Microgrid 623.2.5 Wireless Communication Technologies 653.3 Standards and Protocols in Smart Microgrids 673.3.1 Standards and Protocols for General Communication 673.3.2 Standards and Protocols for Substation Automation 703.3.3 Standards and Protocols for Control Center and Wide Area Monitoring 713.3.4 Standards and Protocols for Distributed Generation and Demand Response 723.3.5 Standards and Protocols for Metering 733.3.6 Standards and Protocols for Electric Vehicle Charging 743.4 Network Cyber-security 753.5 Summary 78References 78Part II Power Management Systems (PMSs) and Energy Management Systems (EMSs) 814 Smart Interfacing Power Electronics Converter Control 834.1 Primary Control of Power Electronics Converters 834.1.1 Basic Control Techniques in Power Converters 844.1.2 Current Control Method 904.1.3 Voltage Control Method 924.2 Virtual Impedance Control of Power Electronic Converters 934.2.1 Internal Virtual Impedance 944.2.2 External Virtual Impedance 964.2.3 Integration of both Internal and External Virtual Impedance 974.3 Droop Control of Power Electronics Converters 994.3.1 Frequency and Voltage Droop Control in an AC Subgrid 994.3.2 Voltage Droop Control in DC Subgrids 1024.3.3 Unified Droop for Interlinking AC and DC Subgrids 1024.3.4 Challenges of Droop Control and Solutions 1054.4 Virtual Synchronous Generator (VSG) Control of Interfacing Power Electronics Converters 1104.4.1 Principles of VSG Control 1114.4.2 Implementation of VSG Control 1124.4.3 Relationship Between Droop Control and VSG Control 1154.5 Unified Control of Power Electronics Converters 1164.6 Summary 118References 1185 Power Management System (PMS) in Smart Hybrid AC/DC Microgrids 1215.1 Introduction 1215.2 Hierarchical Control of Hybrid Microgrids 1225.3 Power Management Systems (PMSs) in Different Structures of Hybrid Microgrids 1255.3.1 PMS of an AC-coupled Hybrid Microgrid 1255.3.2 PMS of a DC-coupled Hybrid Microgrid 1285.3.3 PMS of an AC-DC-coupled Hybrid Microgrid 1305.4 Power Management Strategies During Transitions and Different Loading Conditions 1335.4.1 PMS During Transition Between Grid-Connected and Islanding Operation Modes 1335.4.2 Power Management Strategies Under Different Loading Conditions 1375.5 Implemented Examples of Power Management Systems in Hybrid Microgrids 1375.5.1 PMS Example of an AC-coupled Hybrid Microgrid 1375.5.2 PMS Example of a DC-coupled Hybrid Microgrid 1405.5.3 PMS Example of an AC-DC-coupled Hybrid Microgrid 1435.6 Black Start in Hybrid Microgrids 1465.6.1 General Requirements of Black Start in Microgrids 1475.6.2 Microgrid Black Start Scheme 1475.6.3 Main Issues and Related Measures of Black Starts in Microgrids 1525.7 Summary 153References 1536 Energy Management System (EMS) in Smart Hybrid Microgrids 1556.1 Energy Management in Hierarchical Control of Microgrids 1556.1.1 Hierarchical Control 1556.1.2 Energy Management System 1576.1.3 Communications in an Energy Management System 1626.2 Multi-agent Control Strategy of Microgrids 1626.3 Advance Distribution Management Systems (ADMSs) in Smart Hybrid Microgrids 1656.3.1 Supervisory Control and Data Acquisition (SCADA) 1656.3.2 Geographic Information Systems (GISs) 1676.3.3 Distribution Management System (DMS) 1676.3.4 Automated Meter Reading/Automatic Metering Infrastructure (amr/ami) 1686.3.5 Outage Management Systems (OMSs) 1686.3.6 Distributed Energy Resource Management System (DERMS) 1696.4 Cyber-security in Smart Hybrid Microgrids 1706.4.1 Different Types of Cyber-security Violations 1706.4.2 Impacts of Cyber-security Violations on Smart Microgrids 1726.4.3 Construction of Cyber-security Violations in Smart Microgrids 1736.4.4 Defensive Strategies Against Cyber-attacks 1746.4.5 Case Study Example: Cyber-security Violations in Power Electronics-intensive DC Microgrids 1766.4.6 Future Trends of Microgrid Cyber-security 1816.5 Summary 182References 182Part III Power Quality Issues and Control in Smart Hybrid Microgrids 1857 Overview of Power Quality in Microgrids 1877.1 Introduction 1877.2 Classification of Power Quality Disturbances 1887.2.1 Transients 1887.2.2 Short Duration Variations 1897.2.3 Long Duration Variations 1917.2.4 Voltage Fluctuations 1917.2.5 Voltage Imbalance 1917.2.6 Power Frequency Variations 1927.2.7 Waveform Distortion 1927.3 Overview of Power Quality Standards 1937.4 Mitigation Techniques of Power Quality Problems 1987.4.1 Passive Mitigation Solutions 1987.4.2 Active Mitigation Solutions 2027.5 Power Quality Issues and Compensation in Microgrids 2107.5.1 Power Quality Issues in an AC Microgrid 2107.5.2 Power Quality in a Hybrid AC/DC Microgrid 2137.6 Summary 216References 2168 Smart Microgrid Control During Grid Disturbances 2198.1 Introduction 2198.2 Islanding Detection 2208.2.1 Local Islanding Detection Methods 2218.2.2 Remote Islanding Detection Methods 2258.2.3 Signal Processing Techniques Used in Islanding Detection 2268.2.4 Intelligent Techniques Used in Islanding Detection 2278.3 Fault Ride-through Capability 2288.3.1 Fault Ride-through Requirement 2298.3.2 Ride-through Enhancement 2328.4 Fault Current Contribution and Protection Coordination 2408.4.1 Impact of DG on Fuse-recloser Coordination 2418.4.2 Impact of Reactive Power Injection on Fuse-recloser Coordination 2448.4.3 Example of Inverter Current Control Strategy under RT 2458.5 Summary 250References 2509 Unbalanced Voltage Compensation in Smart Hybrid Microgrids 2539.1 Introduction 2539.2 Control of Individual Three-phase IFCs for Unbalanced Voltage Compensation 2549.2.1 Three-phase IFC Model under Unbalanced Voltage 2559.2.2 Control of Unbalanced Voltage Adverse Effects on IFC Operation 2599.2.3 Adjustable Unbalanced Voltage Compensation with IFC Active Power Oscillation Minimization 2609.3 Control of Parallel Three-phase IFCs for Unbalance Voltage Compensation 2629.3.1 Parallel Three-phase IFCs Model under Unbalanced Voltage 2639.3.2 Parallel Three-phase IFCs Control under Unbalanced Voltage: Redundant IFC for ΔP Cancelation 2679.3.3 Parallel Three-phase IFCs Control under Unbalanced Voltage: All Parallel IFCs Participate in ΔP Cancelation 2719.4 Control of Single-phase IFCs for Three-phase System Unbalanced Voltage Compensation 2769.4.1 System Model with Embedded Single-phase IFCs under Three-phase Unbalanced Voltage 2769.4.2 Reactive Power Control of Single-phase IFCs for Three-phase AC Subgrid Unbalanced Voltage Compensation 2809.5 Summary 288References 28910 Harmonic Compensation Control in Smart Hybrid Microgrids 29110.1 Introduction 29110.2 Control of Interfacing Power Converters for Harmonic Compensation in AC Subgrids 29210.2.1 Harmonics Compensation with the Current Control Method (CCM) 29610.2.2 Harmonics Compensation with the Voltage Control Method (VCM) 29810.2.3 Harmonics Compensation with the Hybrid Control Method (HCM) 30110.2.4 Comparison of Harmonics Compensation with the CCM, the VCM, and the HCM 30510.3 Control of Low-switching Interfacing Power Converters for Harmonics Compensation in an AC Subgrid 30810.3.1 Low-switching Interfacing Converters Sampling Methods 30910.3.2 Control of Low-switching IFCs for Harmonics Compensation with Feed-forward Strategy 31110.4 Control of Interfacing Power Converters for Harmonics Compensation in a DC Subgrid 31710.4.1 Harmonics Compensation in a DC Subgrid Using DC/AC Interlinking Power Converters 31910.4.2 Harmonics Compensation in a DC Subgrid Using DC/DC Interfacing Power Converters 32010.5 Coordinated Control of Multiple Interfacing Power Converters for Harmonics Compensation 32110.5.1 Autonomous Harmonic Control 32210.5.2 Supervisory Harmonic Control 32210.6 Summary 329References 329A Instantaneous Power Theory from Three-phase and Single-phase System Perspectives 331A. 1 Introduction 331A. 2 Principles of Instantaneous Power Theory 331A. 3 Power Control Using Instantaneous Power Theory from a Three-phase System Perspective 333A.3. 1 Reference Current Focusing on Unbalanced Condition Compensation 333A.3. 2 Reference Current Focusing on Active and Reactive Power Oscillation Cancelation 335A. 4 Power Control Using Instantaneous Power Theory from a Single-phase System Perspective 336A. 5 Discussion 338A.5. 1 Example 1: Only Positive Sequence Active Current Injection 338A.5. 2 Example 2: Only Negative Sequence Active Current Injection 340A. 6 Summary 340References 341B Peak Current of Interfacing Power Converters Under Unbalanced Voltage 343B.1 Introduction 343B.2 Peak Currents of Interfacing Converters 343B.2.1 Individual Interfacing Converters 343B.2.2 Parallel Interfacing Converters 346B.3 Maximizing Power/Current Transfer Capability of Interfacing Converters 348B.3.1 Individual IFCs Peak Currents in the Same Phase as the Collective Peak Current of Parallel IFCs 350B.3.2 Individual IFCs Peak Currents In-phase with the Collective Peak Current of Parallel IFCs 357B. 4 Summary 358References 358C case Study System Parameters 359Index 367