About the Authors xiii
Disclaimer xv
List of Figures xvii
List of Tables xxiii
Foreword xxv
Preface xxvii
Acknowledgments xxix
Acronyms and Abbreviations xxxi
1 Introduction 1
1.1 Why Microgrid Research Requires a Network Approach 5
1.2 NSERC Smart MicroGrid Network (NSMG-Net) - The Canadian Experience 7
1.3 Research Platform 8
1.4 Research Program and Scope 9
1.5 Research Themes in Smart Microgrids 10
1.5.1 Theme 1: Operation, Control, and Protection of Smart Microgrids 10
1.5.1.1 Topic 1.1: Control, Operation, and Renewables for Remote Smart Microgrids 12
1.5.1.2 Topic 1.2: Distributed Control, Hybrid Control, and Power Management for Smart Microgrids 12
1.5.1.3 Topic 1.3: Status Monitoring, Disturbance Detection, Diagnostics, and Protection for Smart Microgrids 13
1.5.1.4 Topic 1.4: Operational Strategies and Storage Technologies to Address Barriers for Very High Penetration of DG Units in Smart Microgrids 13
1.5.2 Theme 2 Overview: Smart Microgrid Planning, Optimization, and Regulatory Issues 14
1.5.2.1 Topic 2.1: Cost-Benefits Framework - Secondary Benefits and Ancillary Services 16
1.5.2.2 Topic 2.2: Energy and Supply Security Considerations 16
1.5.2.3 Topic 2.3: Demand Response Technologies and Strategies - Energy Management and Metering 16
1.5.2.4 Topic 2.4: Integration Design Guidelines and Performance Metrics - Study Cases 17
1.5.3 Theme 3: Smart Microgrid Communication and Information Technologies 18
1.5.3.1 Topic 3.1: Universal Communication Infrastructure 20
1.5.3.2 Topic 3.2: Grid Integration Requirements, Standards, Codes, and Regulatory Considerations 20
1.5.3.3 Topic 3.3: Distribution Automation Communications: Sensors, Condition Monitoring, and Fault Detection 20
1.5.3.4 Topic 3.4: Integrated Data Management and Portals 21
1.6 Microgrid Design Process and Guidelines 21
1.7 Microgrid Design Objectives 23
1.8 Book Organization 23
2 Microgrid Benchmarks 25
2.1 Campus Microgrid 25
2.1.1 Campus Microgrid Description 25
2.1.2 Campus Microgrid Subsystems 27
2.1.2.1 Components and Subsystems 27
2.1.2.2 Automation and Instrumentation 28
2.2 Utility Microgrid 30
2.2.1 Description 30
2.2.2 Utility Microgrid Subsystems 32
2.3 CIGRE Microgrid 33
2.3.1 CIGRE Microgrid Description 33
2.3.2 CIGRE Microgrid Subsystems 35
2.3.2.1 Load 35
2.3.2.2 Flexibility 35
2.4 Benchmarks Selection Justification 36
3 Microgrid Elements and Modeling 37
3.1 Load Model 37
3.1.1 Current Source Based 37
3.1.2 Grid-Tie Inverter Based 38
3.2 Power Electronic Converter Models 39
3.3 PV Model 41
3.4 Wind Turbine Model 43
3.5 Multi-DER Microgrids Modeling 44
3.6 Energy Storage System Model 47
3.7 Electronically Coupled DER (EC-DER) Model 49
3.8 Synchronous Generator Model 50
3.9 Low Voltage Networks Model 50
3.10 Distributed Slack Model 51
3.11 VVO/CVR Modeling 53
4 Analysis and Studies Using Recommended Models 57
4.1 Energy Management Studies 57
4.2 Voltage Control Studies 57
4.3 Frequency Control Studies 58
4.4 Transient Stability Studies 58
4.5 Protection Coordination and Selectivity Studies 59
4.6 Economic Feasibility Studies 59
4.6.1 Benefits Identification 59
4.6.2 Reduced Energy Cost 59
4.6.3 Reliability Improvement 60
4.6.4 Investment Deferral 61
4.6.5 Power Fluctuation 61
4.6.6 Improved Efficiency 61
4.6.7 Reduced Emission 62
4.7 Vehicle-to-Grid (V2G) Impact Studies 62
4.8 DER Sizing of Microgrids 62
4.9 Ancillary Services Studies 62
4.10 Power Quality Studies 63
4.11 Simulation Studies and Tools 63
5 Control, Monitoring, and Protection Strategies 65
5.1 Enhanced Control Strategy - Level 1 Function 65
5.1.1 Current-Control Scheme 66
5.1.2 Voltage Regulation Scheme 68
5.1.3 Frequency Regulation Scheme 68
5.1.4 Enhanced Control Strategy Under Network Faults 68
5.2 Decoupled Control Strategy - Level 1 Function 70
5.3 Electronically Coupled Distributed Generation Control Loops - Level 1 Function 71
5.3.1 Voltage Regulation 71
5.3.2 Frequency Regulation 71
5.4 Energy Storage System Control Loops - Level 1 Function 72
5.4.1 Voltage Regulation 72
5.4.2 Frequency Regulation 74
5.5 Synchronous Generator (SG) Control Loops - Level 1 Function 77
5.5.1 Voltage Regulation 77
5.5.2 Frequency Regulation 77
5.6 Control of Multiple Source Microgrid - Level 1 Function 77
5.7 Fault Current Limiting Control Strategy - Level 1 Function 80
5.8 Mitigating the Impact on Protection System - Level 1 Function 80
5.9 Adaptive Control Strategy - Level 2 Function 81
5.10 Generalized Control Strategy - Level 2 Function 81
5.11 Multi-DER Control - Level 2 Function 83
5.12 Centralized Microgrid Controller Functions - Level 3 Function 84
5.13 Protection and Control Requirements 85
5.14 Communication-Assisted Protection and Control 85
5.15 Fault Current Control of DER 86
5.16 Load Monitoring for Microgrid Control - Level 3 Function 87
5.17 Interconnection Transformer Protection 88
5.18 Volt-VAR Optimization Control - Level 3 Function 89
6 Information and Communication Systems 91
6.1 IT and Communication Requirements in a Microgrid 91
6.1.1 HAN Communications 92
6.1.2 LAN Communications 92
6.1.3 WAN Communications 94
6.2 Technological Options for Communication Systems 94
6.2.1 Cellular/Radio Frequency 95
6.2.2 Cable/DSL 95
6.2.3 Ethernet 95
6.2.4 Fiber Optic SONET/SDH and E/GPON over Fiber Optic Links 96
6.2.5 Microwave 96
6.2.6 Power Line Communication 96
6.2.7 WiFi (IEEE 802.11) 96
6.2.8 WiMAX (IEEE 802.16) 96
6.2.9 ZigBee 97
6.3 IT and Communication Design Examples 97
6.3.1 Universal Communication Infrastructure 97
6.3.2 Grid Integration Requirements, Standard, Codes, and Regulatory Considerations 97
6.3.2.1 Recommended Signaling Scheme and Capacity Limit of PLC Under Bernoulli-Gaussian Impulsive Noise 98
6.3.2.2 Studying and Developing Relevant Networking Techniques for an Efficient and Reliable Smart Grid Communication Network (SGCN) 98
6.3.3 Distribution Automation 98
6.3.3.1 Apparent Power Signature Based Islanding Detection 98
6.3.3.2 ZigBee in Electricity Substations 99
6.3.4 Integrated Data Management and Portals 99
6.3.4.1 The Multi Agent Volt-VAR Optimization (VVO) Engine 99
7 Power and Communication Systems 101
7.1 Example of Real-Time Systems Using the IEC 61850 Communication Protocol 103
8 System Studies and Requirements 105
8.1 Data and Specification Requirements 105
8.1.1 Topology-Related Characteristics 107
8.1.2 Demand-Related Characteristics 108
8.1.3 Economics- and Environment-Related Characteristics 108
8.2 Microgrid Design Criteria 108
8.2.1 Reliability and Resilience 108
8.2.1.1 Reliability 109
8.2.1.2 Resilience 109
8.2.2 DER Technologies 109
8.2.2.1 Electric Storage Systems 109
8.2.2.2 Photovoltaic Solar Power 110
8.2.2.3 Wind Power 111
8.2.3 DER Sizing 112
8.2.4 Load Prioritization 114
8.2.5 Microgrid Operational States 114
8.2.5.1 Grid-connected Mode 114
8.2.5.2 Transition to Islanded Mode 115
8.2.5.3 Islanded Mode 115
8.2.5.4 Transition to Grid-connected Mode 116
8.3 Design Standards and Application Guides 116
8.3.1 ANSI/NEMA 116
8.3.2 IEEE 116
8.3.3 UL 118
8.3.4 NEC 118
8.3.5 IEC 118
8.3.6 CIGRE 118
9 Sample Case Studies for Real-Time Operation 121
9.1 Operational Planning Studies 121
9.2 Economic and Technical Feasibility Studies 122
9.3 Policy and Regulatory Framework Studies 123
9.4 Power-Quality Studies 125
9.5 Stability Studies 125
9.6 Microgrid Design Studies 128
9.7 Communication and SCADA System Studies 129
9.8 Testing and Evaluation Studies 129
9.9 Example Studies 130
10 Microgrid Use Cases 133
10.1 Energy Management System Functional Requirements Use Case 133
10.2 Protection 136
10.3 Intentional Islanding 139
11 Testing and Case Studies 143
11.1 EMS Economic Dispatch 143
11.1.1 Applicable Design on the Campus Microgrid 143
11.1.2 Design Guidelines 144
11.1.3 Multi-Objective Optimization - Example 145
11.1.3.1 System Description 145
11.1.3.2 Optimization Formulation 146
11.1.4 Results and Discussion 149
11.1.4.1 Comparison to Existing Campus DEMS 149
11.1.4.2 Business Case Overview 152
11.2 Voltage and Reactive Power Control 153
11.2.1 VVO/CVR Architecture 153
11.3 Microgrid Anti-Islanding 155
11.3.1 Test System 156
11.3.1.1 Distribution System 156
11.3.1.2 Inverter System 158
11.3.2 Tests Performed and Results 158
11.3.2.1 Nuisance Tripping 159
11.3.2.2 Islanding 160
11.4 Real-Time Testing 166
11.4.1 Hardware-In-The-Loop Real Time Test Bench 167
11.4.2 Real-Time System Using IEC 61850 Communication Protocol 169
12 Conclusion 173
12.1 Challenges and Methodologies 173
12.1.1 Theme 1 - Operation, Control, and Protection of Smart Microgrids 173
12.1.1.1 Topic 1.1 - Control, Operation, and Renewables for Remote Smart Microgrids 174
12.1.1.2 Topic 1.2 - Distributed Control, Hybrid Control, and Power Management for Smart Microgrids 176
12.1.1.3 Topic 1.3 - Status Monitoring, Disturbance Detection, Diagnostics, and Protection for Smart Microgrids 180
12.1.1.4 Topic 1.4 - Operational Strategies and Storage Technologies to Address Barriers for Very High Penetration of DG Units in Smart Microgrids 183
12.1.2 Theme 2: Smart Microgrid Planning, Optimization, and Regulatory Issues 185
12.1.2.1 Topic 2.1 Cost-Benefits Framework - Secondary Benefits and Ancillary Services 185
12.1.2.2 Topic 2.2 Energy and Supply Security Considerations 187
12.1.2.3 Topic 2.3 Demand-Response Technologies and Strategies - Energy Management and Metering 190
12.1.2.4 Topic 2.4: Integration Design Guidelines and Performance Metrics - Study Cases 192
12.1.3 Theme 3: Smart Microgrid Communication and Information Technologies 193
12.1.3.1 Topic 3.1 Universal Communication Infrastructure 194
12.1.3.2 Topic 3.2 Grid Integration Requirements, Standards, Codes, and Regulatory Considerations 195
12.1.3.3 Topic 3.3: Distribution Automation Communications: Sensors, Condition Monitoring, and Fault Detection (Topic Leader: Meng; Collaborators: Chang, Li, Iravani, Farhangi, NB Power) 200
12.1.3.4 Topic 3.4: Integrated Data Management and Portals 202
12.2 Final Thoughts 204
References 205
Index 211
