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Control and Filter Design of Single-Phase Grid-Connected Converters
A state-of-the-art discussion of modern grid inverters
In Control and Filter Design of Single-Phase Grid-Connected Converters, a team of distinguished researchers deliver a robust and authoritative treatment of critical distributed power generation technologies, grid-connected inverter designs, and renewable energy utilization. The book includes detailed explanations of the system structure of distributed generation (DG)-grid interface converters and the methods of controlling DG-grid interface voltage source converters (VSCs) with high-order filters.
The authors also explore the challenges and obstacles associated with modern power electronic grid-connected inverter control technology and introduce some designed systems that meet these challenges, such as the grid impedance canceller.
Readers will discover demonstrations of basic principles, guidelines, examples, and design and simulation programs for grid-connected inverters based on LCL/LLCL technology. They will also find:
* A thorough introduction to the architectures of DG-grid interfacing converters, including the challenges of controlling DG-grid interfacing VSCs with high-order filters
* Comprehensive explorations of the control structure and modulation techniques of single-phase grid-tied inverters
* Practical discussions of an LLCL power filter for single-phase grid-tied inverters
* Fulsome treatments of design methods of passive damping for LCL/LLCL-filtered grid-tied inverters
Perfect for researchers, postgraduate students, and senior level undergraduate students of electrical engineering, Control and Filter Design of Single-Phase Grid-Connected Converters will also benefit research & development engineers involved with the design and manufacture of power electronic inverters.
List of contents
Author Biography xiii
Preface xvii
Part I Background 1
1 Introduction 3
1.1 Architecture of DG Grid-Connected Converter 3
1.1.1 Power Conversion Stage 5
1.1.1.1 Switching Network 5
1.1.1.2 Output Filter 6
1.1.2 Control Stage 7
1.2 Challenges for Controlling DG Grid-Connected VSCs with High-Order Power Filter 8
1.2.1 Intrinsic Challenges 8
1.2.1.1 Filter Parametric Sensitivities 9
1.2.1.2 Digital Delay 10
1.2.2 Extrinsic Challenges 10
1.2.2.1 Grid Impedance Variation 10
1.2.2.2 Disturbances at the PCC 10
1.3 Methods for Controlling DG Grid-Connected VSCs with High-Order Power Filter 12
1.3.1 Methodologies to Assess the Stability of DG Grid-Connected VSCs 12
1.3.1.1 Eigenvalue-Based Analysis 12
1.3.1.2 Impedance-Based Stability Analysis 12
1.3.1.3 Application Issue Related to Impedance-Based Stability Analysis 13
1.3.2 Methods to Mitigate Filter Resonance 14
1.3.2.1 Online Grid Impedance Estimation 14
1.3.2.2 Inherent Damping 15
1.3.2.3 Passive Damping 15
1.3.2.4 Active Damping 17
1.3.2.5 Hybrid Damping 19
1.3.3 Harmonic distortion Mitigation Methods 20
1.4 Supplementary Note 21
References 22
2 Control Structure and Modulation Techniques of Single-Phase Grid-Connected Inverter 29
2.1 Control Structure of Single-Phase Grid-Connected Inverter 29
2.1.1 Natural Frame Control 30
2.1.2 Synchronous Reference Frame Control 32
2.1.3 Grid Synchronization Methods 33
2.1.3.1 Zero-Crossing Method 33
2.1.3.2 Filtering of Grid Voltages 34
2.1.3.3 PLL Technique 34
2.2 Modulation Methods 35
2.2.1 Unipolar Modulation Method 35
2.2.1.1 Continuous Unipolar Modulation 36
2.2.1.2 Discontinuous Unipolar Modulation 36
2.2.2 Bipolar Modulation Method 39
2.3 Summary 40
References 41
Part II LCL/LLCL Power Filter 43
3 An LLCL Power Filter for Single-Phase Grid-Connected Inverter 45
3.1 Introduction 45
3.2 Principle of Traditional LCL Filter and Proposed LLCL Filter 46
3.3 Parametric Design of LCL and LLCL Filters 49
3.3.1 Constraints and Procedure of Power Filter Design 49
3.3.2 Saving Analysis on the Grid-Side Inductance 53
3.3.3 Specific Design Consideration for a Simple Passive Damping Strategy 53
3.4 Design Examples for LCL and LLCL filters 54
3.5 Experimental Results 56
3.5.1 Experimental Results 57
3.5.2 Analysis and Discussion 58
3.6 Summary 59
References 59
4 Modeling and Suppressing Conducted Electromagnetic Interference Noise for LCL/LLCL-Filtered Single-Phase Transformerless Grid-Connected Inverter 61
4.1 Introduction 61
4.2 Conducted EMI Noise Analysis 62
4.2.1 CM and DM Voltage Noises 62
4.2.2 Spectrum of DM and CM Voltage Noise for GCI Using DUPWM 64
4.2.3 Spectrum of DM Voltage Noise for GCI Using BPWM 67
4.3 Modified LLCL Filter to Fully Suppress the Conducted EMI Noise for GCI Using DUPWM 68
4.3.1 Modified Solution for LLCL Filter 68
4.3.2 Improved Parameter Design of LLCL filter 72
4.3.3 Constraints on Harmonics of the Grid-Injected Current and EMI Noise Within 150 kHz to 1 MHz 72
4.3.3.1 Constraints on Leakage Current 73
4.3.4 Experimental Verification 74
4.3.4.1 Power Spectrum of the Grid-Injected Current 75
4.3.4.2 M
About the author
Weimin Wu is a Professor in the Department of Electrical Engineering at the Shanghai Maritime University in China.
Frede Blaabjerg is a Professor in the Department of Energy at Aalborg University in Denmark.
Henry Chung is Chair Professor of Electrical Engineering at City University of Hong Kong, China.
Yuanbin He is Associate Professor in the School of Automation at Hangzhou Dianzi University in China.
Min Huang is a Lecturer in the Department of Electrical Engineering at the Shanghai Maritime University in China.
