Advances in Energy System Optimization (eBook)

Preface 6
Contents 8
Part I Demand Response and Distribution Grids 10
An Evolutionary Algorithm for the Optimization of Residential Energy Resources 11
1 Introduction 12
2 Methodology 13
3 Simulation Results 18
4 Conclusion 23
References 24
Comparison of Control Strategies for Electric Vehicles on a Low Voltage Level Electrical Distribution Grid 25
1 Introduction 26
2 Network Model and Load Profiles 27
3 Control Strategies 28
3.1 Direct Control with a Central Aggregator 28
3.2 Indirect Control via a Static Time of Use (TOU) Tariff 30
3.3 Autonomous Control Implementing Reactive Power to Voltage Control 31
4 Results and Discussion 32
4.1 Without Connected Plug-In Electric Vehicles (PEVs) 33
4.2 Direct Control with Perfect Foresight 34
4.3 Indirect Control via a Single Time of Use (TOU) Tariff 34
4.4 Autonomous Control via Reactive Power to Voltage Control 34
5 Conclusion 35
References 35
Part II Optimizing Transmission Grid Operation 37
Optimal Storage Operation with Model Predictive Control in the German Transmission Grid 38
1 Introduction 39
2 Problem Formulation 39
2.1 Time-Constrained Optimal Power Flow 40
2.2 Model Constraints 42
2.3 Solving the Problem 42
3 The German Transmission Grid 43
3.1 Costs 43
4 Reference Solution 46
4.1 Computation 46
4.2 Results 46
5 Model Predictive Control 47
5.1 Computation 47
5.2 Scenarios 48
5.3 Results 48
6 Critical Review 49
7 Conclusion 50
8 Outlook 51
References 51
Security-Constrained Optimization Framework for Large-Scale Power Systems Including Post-contingency Remedial Actions and Inter-temporal Constraints 53
1 Introduction 53
2 Modeling 54
2.1 Area Definitions 54
2.2 Power Flows 54
2.3 Constraints 54
2.4 Degrees of Freedom 56
2.5 Objective Function 58
3 Solution Methodology 60
3.1 Successive Linear Algorithms for OPF Problems 60
3.2 Linearization of Variable Quadripole Parameters 61
3.3 Optimization Problem Speed-Up 62
4 Exemplary Results 66
5 Critical Review 67
6 Conclusions 68
References 68
Part III Flexibility, Storage and Uncertainty Quantification 70
Dispatch of Flexibility Options, Grid Infrastructure and Integration of Renewable Energies Within a Decentralized Electricity System 71
1 Introduction 72
2 Scenario Definition and Methodology of the Two Case Studies 73
2.1 Consideration of Grid Restricitons in Electricity System Modeling 73
2.2 Methodology of the Dispatch Model PowerFlex-Grid 74
2.3 Description of the BMBF Project ``Transparency of Transmission Grid Planning'' and Scenario Definition 75
2.4 Description of the BMWi Project ``D-Flex'' and Scenario Definition 77
3 Results of the Two Case Studies 81
3.1 Results of the BMBF Project ``Transparency of Transmission Grid Planning'' 81
3.2 Results of the BMWi Project ``D-Flex'' 86
4 Critical Review 87
5 Conclusions 88
6 Outlook 89
References 89
Dynamic Decision Making in Energy Systems with Storage and Renewable Energy Sources 91
1 Introduction 91
2 Problem Formulation 93
2.1 State and Exogenous Information 93
2.2 Decisions 94
2.3 State Transition 95
2.4 Objective 96
3 Fundamental Classes of Policies 96
4 The Competing Policies 98
4.1 Policy Function Approximation 98
4.2 Cost Function Approximation 98
4.3 Value Function Approximation 98
4.4 Lookahead Policy 99
5 Selecting the Best Policy 100
5.1 Problem Variations 100
5.2 Computational Results 101
6 Conclusions 104
References 105
Part IV Challenges in Microgrids 106
An Optimal Investment Model for Battery Energy Storage Systems in Isolated Microgrids 107
1 Introduction 109
2 BESS Investment Framework 110
2.1 Model I: Optimal BESS Investment 112
2.2 Model II: Optimal Microgrid Operation 118
3 Results and Analysis 119
3.1 Microgrid Test System 119
3.2 Optimal BESS Investment 120
3.3 Optimal BESS and Microgrid Operations Schedule 121
4 Conclusions 122
References 123
A Dynamic Programming Approach to Multi-period Planning of Isolated Microgrids 124
1 Introduction 125
2 State of the Art 125
3 Problem Definition 126
3.1 Graph Formulation of the Problem 126
3.2 Objective Function and Constraints 127
3.3 Input Data 128
4 Problem Decomposition and Tool Structure 129
4.1 Network Routing 129
4.2 Network Sizing 130
4.3 Constraints Verification and Transition Costs 130
4.4 Investment Timing with Dynamic Programming 131
4.5 Global Structure of the Planning Tool 132
5 Case-Study 132
6 Discussion 136
7 Conclusion 136
References 137
Part V Renewable Energy and Power Grid Expansion Planning 139
Curtailing Renewable Feed-In Peaks and Its Impact on Power Grid Extensions in Germany for the Year 2030 140
1 Introduction 140
2 Input Data and Scenarios 141
2.1 Scenarios of Different RES Integration 141
2.2 Inputdata 142
3 Optimal Transmission Extensions Using Benders Decomposition 144
3.1 Sequential Transmission Capacity Increase 144
3.2 Configuration of the Global Model 144
3.3 Benders Decomposition (BD) 147
3.4 Karush--Kuhn--Tucker-System (KKT-system) for Derivation of the Marginals 149
3.5 Parallel SP for Determing the KKT-marginals 150
3.6 Installation of New HVDC Lines 152
4 Impact of Curtailing Different RES Technologies on Grid Extensions, Overall Costs and Curtailed Energy 152
5 Critical Appraisal 154
6 Conclusion 155
7 Nomenclature 156
References 157
Simulation of Distribution Grid Expansion Costs and the Impact of Load Shifting 159
1 Introduction 159
2 Simulation of the Distribution Grid System in Baden-Württemberg 160
2.1 Regions 161
2.2 Grid Topology 162
2.3 Electricity Demand and Generation 163
2.4 Load Flow 163
2.5 Line Extensions 165
2.6 Use of Load Shifting to Prevent Line Extension 166
3 Scenarios 166
4 Required Line Extension 166
5 Costs of the Grid Extension 168
6 Critical Review 168
7 Conclusion and Outlook 170
References 170
Part VI Data Provision for Power Grid Modeling 172
Structure Analysis of the German Transmission Network Using the Open Source Model SciGRID 173
1 Introduction 174
2 Power Data in OSM and the SciGRID Model 175
2.1 OpenStreetMap 175
2.2 The SciGRID Model 176
2.3 The German Transmission Network 176
3 Structure of the German Transmission Grid 177
3.1 Complexity Reduction 179
3.2 Discussion 181
4 Conclusions 183
References 183
Modeling of the Transmission Grid Using Geo Allocation and Generalized Processes 185
1 Introduction 185
2 Public Grid Data Sets 186
2.1 Data Sets of Existing Transmission Lines 187
2.2 Future Grid Projects 188
2.3 Geo Allocation and Merging into Standardized Lists 189
3 Process Model 190
3.1 Definition of a Generalized Process 190
3.2 General Approach 191
3.3 Modification for the Integration of Grid Processes 191
3.4 Assumptions for Grid Processes 192
3.5 Implementation in a Database Environment 193
4 Integration of Grid Data in Energy System Models 193
4.1 Nodal Allocation of Load and Production Data 194
4.2 Virtual Network in Peripheral Regions 195
5 Resulting Transmission Grid Model 197
6 Critical Review 199
7 Conclusion and Outlook 199
References 200
Regionalizing Input Data for Generation and Transmission Expansion Planning Models 201
1 Introduction 202
2 Selected Approaches in Power Generation and Transmission Planning and Their Handling of Regionalized Input Data 203
3 The Developed Approach for a Dynamic Assignment of Generation and Load Data to Varying Topologies of the Transmission Grid 204
4 Case Study: Regionalization of Input Data for the Transmission Network Planning in Germany 207
5 Conclusions and Outlook 211
References 212
Part VII Convex Versus Nonconvex Approaches for Power Flow Analysis 214
Convexity/Nonconvexity Certificates for Power Flow Analysis 215
1 Introduction 215
2 Convexity of Quadratic Transformations 216
3 Certificates of Convexity/Nonconvexity 217
4 Numerical Results 219
5 Conclusions and Future Work 223
References 223
A Convex Model for the Optimization of Distribution Systems with Distributed Generation 225
1 Introduction 225
2 Steady-State Representation of PDS 227
2.1 Representation of Voltage Violation 227
2.2 Representation of Power Losses 228
2.3 Representation of Generators 229
3 Optimization Model 230
3.1 Constraints 231
4 Tests and Results 232
4.1 DG as a PV Bus 234
4.2 DG as a PQ Bus 235
4.3 Determination of the DG Operation Point 236
5 Conclusions 237
References 239