This book covers modeling, control and stability aspects of hybrid AC/DC power networks. More specifically, this book provides an in-depth analysis of the stability and control aspects of hybrid AC/DC power grids, with comprehensive coverage of theoretical aspects of conventional stability issues (e.g., small-signal stability, voltage stability and frequency stability), emerging stability issues (e.g., converter associated stability) and control strategies applied in this emerging hybrid AC/DC power grids. This book takes a more pragmatic approach with a unique compilation of timely topics related to hybrid AC/DC networks compared with other books in this field. Therefore, this book provides the reader with comprehensive information on modeling, control and stability aspects which need to consider when modeling and analysis of hybrid AC/DC power grids for power system dynamics and stability studies.
Each chapter provides fundamental stability theories, some worked examples and case studies to explain various modeling, analysis and control concepts introduced in the chapter. Therefore, postgraduate research students, power system researchers and power system engineers benefit from the materials presented in this book and assist them to model and device new control strategies to overcome the stability challenges of the emerging hybrid AC/DC power grid.
Author(s): Lasantha Meegahapola, Siqi Bu, Mingchen Gu
Series: Power Systems
Publisher: Springer
Year: 2022
Language: English
Pages: 284
City: Cham
Preface
Contents
Acronyms
1 Introduction
1.1 Background
1.2 HVDC Transmission Systems
1.2.1 The Key Components of the HVDC
1.2.2 The Advantages and Functionalities of HVDC Systems
1.2.3 HVDC Technology Selection Criteria
1.3 Emergence of Hybrid AC/DC Power Grids
1.3.1 Stability and Operation Challenges of Hybrid AC/DC Power Grids
1.4 Medium Voltage and Low Voltage Hybrid AC/DC Power Grids
1.5 Chapter Summary
References
2 Overview of HVDC Technologies and Power System Stability
2.1 Introduction
2.2 Line Commutated Converter HVDC Technology
2.2.1 LCC HVDC Fundamentals
2.2.2 LCC PQ Capability Diagram
2.3 Voltage Source Converter HVDC Technology
2.3.1 Two-Level Converter
2.3.2 Multi-level Converter with Clamping Circuit
2.3.3 VSC PQ Capability Chart
2.3.4 Modular Multi-level Converter Based HVDC Technology
2.3.5 Comparison of VSC Technologies
2.4 Hybrid LCC–VSC HVDC Systems
2.5 Comparison of LCC and VSC Technologies and Selection Criteria
2.6 An Overview of Power System Stability
2.6.1 Rotor Angle Stability
2.6.2 Voltage Stability
2.6.3 Frequency Stability
2.6.4 Resonance Stability
2.6.5 Converter Driven Stability
2.6.6 Oscillatory Stability
2.7 Chapter Summary
References
3 Modelling and Control of Hybrid AC/DC Power Grids
3.1 Introduction
3.2 Modelling of HVDC Converter Stations
3.2.1 Modelling of Line Commutated Converters
3.2.2 Power Injection Modelling of Voltage Source Converters
3.2.3 Modelling of VSCs in Dq Reference Frame
3.3 Modelling of HVDC Lines
3.4 Control of HVDC and Hybrid AC/DC Networks
3.4.1 Terminal Control
3.4.2 System Level Control
3.4.3 Control Techniques Used in Current and Primary Control Schemes
3.5 AC Grid Representation in Hybrid AC/DC Power Grids
3.6 Modelling and Control of Point-To-Point HVDC Transmission System
3.7 Modelling and Control of MTDC Systems
3.8 Chapter Summary
References
4 Rotor Angle Stability of Hybrid AC/DC Power Grids
4.1 Introduction
4.2 Overview of Rotor Angle Stability
4.2.1 Transient Stability
4.2.2 Small-Disturbance Stability
4.3 Transient Stability Analysis of Hybrid AC/DC Power Grids
4.4 Small-Signal Modelling of Hybrid AC/DC Power Grids
4.4.1 LCC Based HVDC System Modelling
4.4.2 VSC Based HVDC System Modelling
4.4.3 Hybrid AC/DC System Modelling
4.5 Eigenvalue Analysis and Eigenvalue Sensitivity Analysis
4.5.1 Eigenvalue and Eigenvector
4.5.2 Eigenvalue Analysis
4.5.3 Eigenvalue Sensitivity Analysis
4.6 Small-Disturbance Time-Domain Analysis
4.7 Chapter Summary
References
5 Voltage Stability and Control Aspects of Hybrid AC/DC Power Grids
5.1 Introduction
5.2 Voltage Stability Definition and Classification
5.3 AC Large-Disturbance Voltage Stability and Fault Ride-Through
5.3.1 Fault Ride-Through Capability of HVDC Systems
5.3.2 Fault Ride-Through Improvement
5.3.3 Large-Disturbance Stability in AC Network
5.4 AC Small-Disturbance Voltage Stability Analysis of Hybrid AC/DC Power Grids
5.4.1 AC Small-Disturbance Voltage Stability Analysis by Voltage Sensitivity Factor Method
5.4.2 AC Small-Disturbance Voltage Stability Analysis by Maximum Power Curve Method
5.5 DC Small-Disturbance Voltage Stability Analysis and Control of Hybrid AC/DC Power Grids
5.6 Small-Disturbance Voltage Stability Control and Enhancement of Hybrid AC/DC Power Grids
5.7 Advanced Voltage Stability Analysis of Hybrid AC/DC Power Grids
5.7.1 Cumulant Theory Based Analytical Method of Probabilistic Small-Disturbance Voltage Stability Analysis of a Hybrid AC/DC Power System
5.7.2 Multi-point Linearisation Technique
5.7.3 Assessment on Variance Indices of Probabilistic Small-Disturbance Voltage Stability of a Hybrid AC/DC Power System
5.8 Chapter Summary
References
6 Frequency Stability and Control of Hybrid AC/DC Power Grids
6.1 Introduction
6.2 Frequency Stability Classification in Power Grids
6.2.1 Inertial Response
6.2.2 Primary Response
6.2.3 Secondary Response
6.2.4 Tertiary Response
6.3 Frequency Stability Issues in Hybrid AC/DC Power Grids
6.3.1 Frequency Response from Power Sources in the Same Sub-Grid
6.3.2 Frequency Response from Power Sources in Other Sub-grids
6.4 Frequency Control and Stability Improvement Schemes in Hybrid AC/DC Power Grids
6.4.1 Local Frequency Regulator
6.4.2 Coordinated Frequency Regulator
6.5 Chapter Summary
References
7 Low Short-Circuit Strength and Converter Associated Stability Issues
7.1 Introduction
7.2 Overview of Converter Associated Stability Issues and Classification
7.2.1 Instability Due to Weak Grid Conditions
7.2.2 Converter Control Interactions
7.2.3 Converter Control Induced Resonances
7.3 Characterisation of System Strength
7.4 Stability and Operation Issues Under a Low Short-Circuit Strength
7.4.1 Large Voltage Variations and Voltage Swings
7.4.2 Commutation Failure of LCC Based HVDC Stations
7.4.3 Limitations on Maximum DC Power Transfer
7.4.4 PLL and Current Control Loop Stability Issues
7.4.5 Other Stability and Operation Issues
7.5 Strategies to Improve Stability Under Low Short-Circuit Strength
7.5.1 Improved Converter Topology
7.5.2 Enhanced Control Schemes and PLLs
7.5.3 Implementation of Fast Responsive Reactive Power Compensation Devices
7.5.4 Reducing the Thévenin’s Equivalent Impedance
7.6 Converter Control Interactions
7.6.1 Classification of Converter Control Interactions
7.6.2 Assessment and Optimisation of Converter Control Interactions
7.7 Converter Control Induced Resonances
7.7.1 Connection Between Converter Control Induced DDSSO and IGE
7.7.2 Assessment and Mitigation of Converter Control Induced Resonances
7.8 Chapter Summary
References
8 Multi-objective Coordinated Control of Hybrid AC/DC Power Grids
8.1 Introduction
8.2 Multi-objective Coordinated Control Schemes
8.2.1 Frequency and DC Voltage Control
8.2.2 Voltage Regulation and Power Sharing
8.2.3 Loss Minimisation
8.2.4 Oscillation Damping
8.3 MPC-Based Control Schemes
8.3.1 The Structure of the MPC
8.3.2 Discrete Plant Model
8.3.3 Cost Function
8.3.4 Constraints
8.3.5 The Operation Process of MPC
8.3.6 State Estimate Predictive Control
8.4 Chapter Summary
References
Appendix A Coordinate Transformations
Appendix B 16-Machine 68-Node NYPS-NETS Power System
Appendix C The CIGRE B4 DC Grid Test System Data
Index
