| | Analysis of the Maximum Wind Energy Penetration in the Island |
| | 1,83 | | MB | of Crete |
| | 86 | | stron |
| | 5276 | | ID | University of Strathclyde |
| | 2005 | | rok |
| | CONTENTS |
| | 1 Introduction.9 |
| | 2 Wind Energy in Greece.10 |
| | 2.1 The Electricity System in Greece12 |
| | 2.2 Electricity System in Greek Islands.14 |
| | 2.3 The Development of Renewable Energy Sources in Greece.15 |
| | 2.4 Wind Energy Development in Greece.16 |
| | 2.5 The Case Study of Crete.17 |
| | 2.6 Wind Energy Development in Crete19 |
| | 3 Wind Turbines - technical issues21 |
| | 3.1 Wind Turbine’s Components and Electricity Generation.21 |
| | 3.2 Considerations for Wind Turbines Development.22 |
| | 3.2.1 Small unit sizes.22 |
| | 3.2.2 Wind Variability.22 |
| | 3.2.3 Electrical properties23 |
| | 3.3 Electrical Machines23 |
| | 3.3.1 Synchronous machine24 |
| | 3.3.2 Asynchronous or Induction machine27 |
| | 3.4 Generator Systems used in Wind Industry31 |
| | 3.4.1 Constant speed WT with squirrel cage induction generator (CT).31 |
| | 3.4.2 Variable speed WT with doubly-fed (wound-rotor) induction generator (VTDI).31 |
| | 3.4.3 Variable speed WTs with direct-drive synchronous generator (VTDD)32 |
| | 3.5 Transmission to the Grid.32 |
| | 3.6 The Electrical grid33 |
| | 3.6.1 Frequency control.33 |
| | 3.6.2 Fast frequency control on the level of an individual station: the droop line;.34 |
| | 3.6.3 Integral control to reset the frequency to 50 Hz after an offset has occurred;.35 |
| | 3.6.4 Production switching.35 |
| | 3.6.5 Finally in case of emergency: load shedding, switching of grid sections off the grid.35 |
| | 3.7 Voltage control35 |
| | 3.8 Impact of Connecting Wind Turbines to the Distribution Network.36 |
| | 3.8.1 Voltage flicker.37 |
| | 3.8.2 Harmonics39 |
| | 3.8.3 Voltage Variation39 |
| | 3.8.4 Reverse Power Flows.40 |
| | 3.8.5 Fault Levels.40 |
| | 3.8.6 Thermal Limits40 |
| | 3.8.7 Transient Stability.41 |
| | 3.8.8 Protection.41 |
| | 4 Power Flow Analysis.42 |
| | 4.1 Bus Admittance Matrix.43 |
| | 4.2 Solution of Non-Linear Algebraic Equations.46 |
| | 4.2.1 Gauss–Siedel Method46 |
| | 4.2.2 Newton-Raphson Method.48 |
| | 4.3 Power Flow Solution50 |
| | 4.4 Power Flow Equation.51 |
| | 4.5 Gauss-Seidel Power Flow Solution.52 |
| | 4.6 Line Flows and Losses54 |
| | 4.7 Tap Changing Transformers.55 |
| | 4.8 Power Flow Programs.56 |
| | 4.9 Data Preparation57 |
| | 4.10 Newton-Raphson Power Flow Solution58 |
| | 4.11 Fast Decoupled Power Flow Solution.62 |
| | 5 Methodology and Results66 |
| | 5.1 The Electric Grid in the Island of Crete.66 |
| | 5.2 Demand and Electricity Production in Crete.68 |
| | 5.3 Power Flow Analysis.70 |
| | 5.3.1 Data Preperation.70 |
| | 5.3.2 Newton-Raphson Method.73 |
| | 5.3.3 Gauss-Seidel Method.75 |
| | 5.3.4 Line Flow Analysis and Losses.77 |
| | 5.4 Thermal Limitations.79 |
| | 6 Conclusions80 |
| | 7 References.84 |