Photovoltaic Sources Modeling

Acknowledgements xi

Introduction xiii

Tables of Symbols and Acronyms xv

1 PV Models 1

1.1 Introduction 1

1.2 Modeling: Granularity and Accuracy 1

1.3 The Double-diode Model 2

1.4 The Single-diode Model 4

1.4.1 Effect of the SDM Parameters on the I-V Curve 5

1.5 Models of PV Array for Circuit Simulator 6

1.5.1 The Single-diode Model based on the Lambert W-function 10

1.6 PV Dynamic Models 11

1.7 PV Small-signal Models and Dynamic-resistance Modelling 14

References 17

2 Single-diode Model Parameter Identification 21

2.1 Introduction 21

2.2 PV Parameter Identification from Datasheet Information 21

2.2.1 Exact Numerical Methods 21

2.2.2 Approximate Explicit Solution for Calculating SDM Parameters 24

2.2.3 Validation of the Approximate Explicit Solution 27

2.3 Single-diode Model Simplification 30

2.3.1 Five-parameter versus Four-parameter Simplification 32

2.3.2 Explicit Equations for Calculating the Four SDM Parameters 34

2.4 Improved Models for Amorphous and Organic PV Technologies 37

2.4.1 Modified SDM for Amorphous PV Cells 37

2.4.2 Five-parameter Calculation for Amorphous Silicon PV Panels 38

2.4.3 Modified Model for Organic PV Cells 40

References 43

3 PV Simulation under Homogeneous Conditions 45

3.1 Introduction 45

3.2 Irradiance- and Temperature-dependence of the PV Model 45

3.2.1 Direct Effects of Irradiance and Temperature 45

3.2.2 Equations for "Translating" SDM Parameters 49

3.2.3 Iterative Procedure proposed by Villalva et al. 51

3.2.4 Modified PV Model proposed by Lo Brano et al. 52

3.2.5 Translating Equations proposed by Marion et al. 53

3.2.6 Modified Translational Equation proposed by Picault et al. 53

3.2.7 PV Electrical Model proposed by King et al. 56

3.2.8 Using the King Equation for Estimating the SDM Parameter Drift 59

3.3 Simplified PV Models for Long-term Simulations 61

3.3.1 King Equations for Long-term Simulations 63

3.3.2 Performance Prediction Model based on the Fill Factor 68

3.3.3 PV Modeling based on Artificial Neural Networks 69

3.4 Real-time Simulation of PV Arrays 71

3.4.1 Simplified Models including the Power Conversion Stage 72

3.5 Summary of PV Models 75

References 77

4 PV Arrays in Non-homogeneous Conditions 81

4.1 Mismatching Effects: Sources and Consequences 81

4.1.1 Manufacturing Tolerances 81

4.1.2 Aging 82

4.1.3 Soiling and Snow 83

4.1.4 Shadowing 83

4.1.5 Module Temperature 86

4.2 Bypass Diode Failure 87

4.3 Hot spots and Bypass Diodes 89

4.4 Effect of Aging Failures and Malfunctioning on the PV Energy Yield 90

References 94

5 Models of PV Arrays under Non-homogeneous Conditions 97

5.1 The use of the Lambert W-Function 98

5.2 Application Examples 102

5.2.1 The Entire I-V Curve of a Mismatched PV String 102

5.2.2 The Operating Point of a Mismatched PV String 104

5.3 Guess Solution by Inflection-point Detection 106

5.4 Real-time Simulation of Mismatched PV Arrays 108

5.5 Estimation of the Energy Production of Mismatched PV Arrays 109

References 111

6 PV array Modeling at Cell Level under Non-homogeneous Conditions 113

6.1 PV Cell Modeling at Negative Voltage Values 113

6.1.1 The Bishop Term 113

6.1.2 Silicon Cells Type and Reverse Behavior 115

6.2 Cell and Subcell Modeling: Occurrence of Hot Spots 116

6.2.1 Cell Modeling 117

6.3 Simulation Example 121

6.4 Subcell PV Model 123

6.5 Concluding Remarks on PV String Modeling 124

References 124

7 Modeling the PV Power Conversion Chain 127

7.1 Introduction 127

7.2 Review of Basic Concepts for Modeling Power Converters 129

7.2.1 Steady-state Analysis 132

7.2.1.1 Steady-state Values 133

7.2.1.2 Ripple Magnitudes 133

7.2.2 Converter Dynamics Analysis 134

7.3 Effects of the Converter in the Power Conversion Chain 136

7.3.1 Steady-state Model of the Power Conversion Chain 136

7.3.2 Analysis and Simulation using the Steady-state Model 139

7.3.3 Voltage Ripple at the Generator Terminals 143

7.3.4 I-V Curve of the Power Conversion Chain 148

7.4 Modelling the Dynamics of the Power Conversion Chain 151

7.5 Additional Examples 159

7.5.1 MIU based on a Buck Converter 159

7.5.2 MIU based on a Buck-Boost Converter 161

7.6 Summary 162

References 163

8 Control of the Power Conversion Chain 165

8.1 Introduction 165

8.2 Linear Controller 166

8.3 Sliding-mode Controller 172

8.3.1 Inductor Current Control 173

8.3.2 Capacitor Current Control 179

8.4 Summary 183

References 184

Index 000