Integration of Distributed Generation in the Power System

The integration of new sources of energy like wind power, solar-power, small-scale generation, or combined heat and power in the power grid is something that impacts a lot of stakeholders: network companies (both distribution and transmission), the owners and operators of the DG units, other end-users of the power grid (including normal consumers like you and me) and not in the least policy makers and regulators. There is a lot of misunderstanding about the impact of DG on the power grid, with one side (including mainly some but certainly not all, network companies) claiming that the lights will go out soon, whereas the other side (including some DG operators and large parks of the general public) claiming that there is nothing to worry about and that it's all a conspiracy of the large production companies that want to protect their own interests and keep the electricity price high. The authors are of the strong opinion that this is NOT the way one should approach such an important subject as the integration of new, more environmentally friendly, sources of energy in the power grid. With this book the authors aim to bring some clarity to the debate allowing all stakeholders together to move to a solution. This book will introduce systematic and transparent methods for quantifying the impact of DG on the power grid.

Auteur

MATH H.J. BOLLEN, PhD, is Senior Specialist with STRI AB,
Gothenburg, Sweden; Professor in Electric Power Engineering at
Luleå University of Technology, Skellefteå, Sweden; and a
technical expert with the Energy Markets Inspectorate in
Eskilstuna, Sweden. He is a Fellow of the IEEE.

FAINAN HASSAN, PhD, is with the Alstom Grid (previously Areva
T&D), Research & Technology Centre, Stafford, United
Kingdom. A member of the IEEE, she has also worked as a
seniorengineer for STRI AB, Gothenburg, Sweden.

Texte du rabat

A forward-thinking power-system viewpoint on the increased integration of distributed generation into the grid

Alternative, renewable sources of energy are often referred to as "distributed generation" (DG). The electric power system plays an essential role in transporting and allowing the use of this energy, and much controversy surrounds the question of the true hosting capacity of the grid when it comes to DG. This book introduces systematic and transparent methods for quantifying the effect of DG on the power system, either at a specific grid location or in the grid as a whole. It shows how to calculate—and increase—the hosting capacity for different types of networks and various types of DG, with emphasis on wind power, solar power, and combined heat and power.

This book is the first to explain the background of the "hosting capacity approach"—using the existing power system as a starting point and considering how DG changes the performance of the system when no additional measures are taken—and to provide numerous examples. The heart of the book outlines the problems surrounding the integration of DG in detail: increased risk of overload and increased losses; increased risk of overvoltages; increased levels of power-quality disturbances; incorrect operation of the protection; and the impact on power-system stability and operation. Specific solutions are discussed, ranging from building more lines and using power-electronics control to smart grids and microgrids. Theoretical models and research results are also presented.

This is also the first book to go into detail on both the "shallow" and "deep" impact of DG; it describes the impact of small generation on the distribution system and on the operation of the transmission system. Emphasizing that the introduction of DG should not result in unacceptable performance of the power grid, the authors discuss several improvements that could be made in the network, on either the production or consumption side, to enable this.

Integration of Distributed Generation in the Power System is an important resource for engineers and researchers working on power systems and the connection/integration of DG to the power system; equipment manufacturers; wind-power developers; government regulators; and undergraduate and postgraduate students in the power engineering and energy fields.

Contenu
PREFACE xi ACKNOWLEDGMENTS xiii

CHAPTER 1 INTRODUCTION 1

CHAPTER 2 SOURCES OF ENERGY 6

2.1 Wind Power 7

2.1.1 Status 7

2.1.2 Properties 7

2.1.3 Variations in Wind Speed 8

2.1.4 Variations in Production Capacity 10

2.1.5 The Weibull Distribution of Wind Speed 20

2.1.6 Power Distribution as a Function of the Wind Speed 22

2.1.7 Distribution of the Power Production 26

2.1.8 Expected Energy Production 29

2.2 Solar Power 30

2.2.1 Status 30

2.2.2 Properties 31

2.2.3 Space Requirements 32

2.2.4 Photovoltaics 33

2.2.5 Location of the Sun in the Sky 35

2.2.6 Cloud Coverage 39

2.2.7 Seasonal Variations in Production Capacity 42

2.2.8 Fast Variations with Time 46

2.3 Combined Heat-and-Power 50

2.3.1 Status 50

2.3.2 Options for Space Heating 51

2.3.3 Properties 52

2.3.4 Variation in Production with Time 53

2.3.5 Correlation Between CHP and Consumption 56

2.4 Hydropower 59

2.4.1 Properties of Large Hydro 60

2.4.2 Properties of Small Hydro 61

2.4.3 Variation with Time 61

2.5 Tidal Power 65

2.6 Wave Power 66

2.7 Geothermal Power 67

2.8 Thermal Power Plants 68

2.9 Interface with the Grid 71

2.9.1 Direct Machine Coupling with the Grid 72

2.9.2 Full Power Electronics Coupling with the Grid 73

2.9.3 Partial Power Electronics Coupling to the Grid 75

2.9.4 Distributed Power Electronics Interface 79

2.9.5 Impact of the Type of Interface on the Power System 80

2.9.6 Local Control of Distributed Generation 81

CHAPTER 3 POWER SYSTEM PERFORMANCE 84

3.1 Impact of Distributed Generation on the Power System 84

3.1.1 Changes Taking Place 84

3.1.2 Impact of the Changes 85

3.1.3 How Severe Is This? 86

3.2 Aims of the Power System 87

3.3 Hosting Capacity Approach 88

3.4 Power Quality 91

3.4.1 Voltage Quality 92

3.4.2 Current Quality 92

3.4.3 Multiple Generator Tripping 93

3.5 Voltage Quality and Design of Distributed Generation 95

3.5.1 Normal Operation; Variations 96

3.5.2 Normal Events 96

3.5.3 Abnormal Events 97

3.6 Hosting Capacity Approach for Events 98

3.7 Increasing the Hosting Capacity 100

CHAPTER 4 OVERLOADING AND LOSSES 102

4.1 Impact of Distributed Generation 102

4.2 Overloading: Radial Distribution Networks 105

4.2.1 Active Power Flow Only 105

4.2.2 Active and Reactive Power Flow 108

4.2.3 Case Study 1: Constant Production 109 4.2.4 Case Study 2: Wind Power 110</p&gt...