Grid-Forming Power Inverters: Control and Applications

Cover
Half Title
Title Page
Copyright Page
Table of Contents
Preface
Editors
Contributors
Introduction
Chapter 1 Introduction to Grid-Forming Inverters
1.1 Overview
1.2 Virtual Synchronous Generator
1.3 GFL and GFM Inverters
1.4 Comparison Between GFLIs and GFMIs
1.5 Framework Modeling
1.6 Methods of GFMI Control
1.7 Challenges of Grid-Forming Inverters
1.8 Discussion
1.9 Conclusion
References
Chapter 2 Requirements and Grid Standards for Grid-Forming Inverters
2.1 Introduction
2.2 System Scarcities and Stability Issues with High Share of IBRs
2.3 Comparison of GFMI, Grid-Following Inverter, and Synchronous Sources: System Services Perspective
2.4 Overview of System Services From GFMIs and Performance Requirements
2.5 Challenges Associated with Large-Scale Integration of GFMI
2.6 Pathways for Wide-Scale Adoption of GFMI in Power System
2.7 State of Play and Advancements in GFMI Grid Codes
2.8 Conclusions
References
Chapter 3 Power System Requirements for Grid-Forming Converters
3.1 Introduction: Background and Driving Forces
3.2 Frequency Response and Control
3.2.1 Inertia
3.2.2 Primary Frequency and Droop Control
3.2.3 Fast Frequency Response
3.2.4 Needs for Energy Reserve/Storage to Enable Grid-Forming Capability
3.3 Active Power Requirements
3.4 Fast Fault Current Injection and Short Circuit Contribution
3.5 Fault Ride-Through
3.5.1 Voltage Ride-Through
3.5.2 Frequency Ride-Through
3.6 Reactive Power Requirements and Voltage Regulation
3.7 Black Start and Island Operation
References
Chapter 4 Toward Performance-Based Requirements and Generic Models for Grid-Forming Inverters
4.1 Introduction
4.2 Operational Similarity Across Different Grid-Forming Control Types
4.2.1 Type B Droop-Based Grid-Forming Control
4.2.2 Grid-Forming Control Comparison
4.3 Toward Performance-Based Interconnection Requirements for Grid-Forming Inverters
4.4 Generic Model Development for Large System Studies
4.5 Conclusion
References
Chapter 5 An Overview of Modeling and Control of Grid-Forming Inverters
5.1 Introduction
5.2 Basic Definition of Grid-Forming Converters
5.3 Modeling of Grid-Forming Converters
5.4 Control of Grid-Forming Converters
5.4.1 General Control Structure of Grid-Forming Converters
5.4.2 Outer Loop: Power Synchronization Loop
5.4.3 Outer Loop: Voltage Profile Management
5.4.4 Inner Loop: Calculation of Modulation Signals
5.4.4.1 Cascade Control by Using Sliding Mode Controller for Current Controller
5.4.4.2 Direct Voltage Control by Using Sliding Mode Controller
5.4.4.3 Direct Voltage Control by Using Fractional-Order Sliding Mode Controller
5.5 Summary
References
Chapter 6 Small-Signal Modeling and Validation Including State-Space and Admittance Models of the Virtual Synchronous Machine
6.1 Introduction
6.2 Introduction of the Studied System and Modeling Method
6.2.1 System Description
6.3 CCM Description
6.4 Small-Signal Modeling of VSM
6.4.1 LCL Filter Model
6.4.1.1 Basic Electrical Model
6.4.1.2 Resonance Frequency Damping
6.4.2 Combined dq – Frame Voltage, Current PI Control, and PWM Delay
6.4.2.1 Current Control Loop
6.4.2.2 Voltage Control Loop
6.4.2.3 Padé Approximation
6.4.2.4 Combined Voltage and Current Control Loop
6.4.3 Shaft Swinging Emulation
6.4.3.1 Swing Equation
6.4.3.2 Power Regulation
6.4.3.3 Low-Pass Filter (LPF)
6.4.3.4 Swing Equation with Power Filter
6.5 Reactive Power Control
6.5.1 Implementation Using the LPF and Droop Control
6.6 Frame Rotation
6.7 Derivation and Validation of the Whole-System Small-Signal Model
6.7.1 Derivation and Validation of the State-Space Model
6.7.1.1 Time Domain Validation
6.8 Derivation and Validation of the Admittance Model
6.9 Conclusion
References
Chapter 7 Grid-Forming Control of Doubly Fed Induction Generators
7.1 Introduction
7.2 System Description
7.3 DFIG Dynamic Model
7.4 DFIG Equivalent Circuit
7.5 DFIG Electromagnetic Torque and Reactive Power
7.6 DFIG Torque Synchronization Loop
7.7 DFIG Rotor Flux Control
7.8 Simulation Results
7.8.1 DFIG Response to a Step in Wind Velocity at Partial Load
7.8.2 DFIG Response to a Step Command in Reactive Power
7.8.3 DFIG Response to a System Load Step
7.8.4 Wind Farm (WF) Response to a Load Step
7.8.5 DFIG Response to the Transition from Grid Connected to Isolated
7.9 Conclusions
Appendix
References
Chapter 8 Damping Power System Oscillations Using Grid-Forming Converters
8.1 Introduction
8.2 System Description and Modeling
8.3 Grid-Forming Converter Stabilizer
8.4 STATCOM Stabilizer
8.5 Stability Analysis
8.5.1 Small-Signal Stability
8.5.2 Time-Domain Response
8.6 Two-Area System
8.6.1 Eigenvalues Loci Under Variation of Parameters
8.6.2 Dynamic Response to a Load Change
8.6.3 Dynamic Response to a Line Tripping
8.7 Conclusions
Appendix A. System Parameters and Operation Points
Appendix B. Linearized Models
Appendix C. Models Parameters
References
Chapter 9 Grid-Forming Dynamic Stability Under Large Fault Events – Application to 100% Inverter-Based Irish Power System
9.1 Grid-Forming Requirements for Future Grids with High Shares of Renewables
9.2 GFMI Modelling, Current Limiting, and Control Design
9.2.1 Droop Control with Inner Cascaded Voltage and Current PI Control Loops
9.2.2 Virtual Synchronous Machine Control
9.2.3 Dispatchable Virtual Oscillator Control-Based Grid-Forming Inverter Modelling
9.2.4 Grid-Forming Inverter Angular Speed Freezing
9.3 Irish Grid Case Study With 100% GFMIs
9.3.1 Urban and Remote Grid Models
9.3.2 Urban Irish Grid with 100% GFMIs (Droop, dVOC Control)
9.3.3 Remote Irish Grid with 100% GFMIs (Current Limiting Strategies and Virtual Angular Speed Freezing)
9.3.3.1 Current Saturation and Virtual Impedance Limiting Control
9.3.3.2 GFMI Transient Stability Enhanced by Virtual Angular Speed Freezing
9.4 Conclusions
References
Chapter 10 Virtual Oscillator-Controlled Grid-Forming Inverters Incorporating Online Parametric Grid Impedance Identification
10.1 Overview
10.2 Introduction
10.3 Conventional VOC
10.4 Proposed Implementation of Online Grid Impedance Estimation for dVOC
10.5 Non-Parametric Grid Impedance Estimation Based on PRBS Injection
10.5.1 Disturbance Injection
10.5.2 Non-Parametric GIE
10.6 Parametric Impedance Based on Complex Curve Fitting
10.7 Simulation Results
10.7.1 Active and Reactive Power Dispatch
10.7.2 Online GIE
10.7.3 Effects of Notch Filter on THD%
10.8 HIL Experimental Results
10.8.1 Active and Reactive Power Dispatch
10.8.2 Online GIE
10.9 Chapter Summary
References
Chapter 11 Grid-Forming Inverters Interfacing Battery Energy Storage Systems
11.1 Introduction
11.2 Inverter Architecture
11.3 Control Architecture for GFM Inverter
11.3.1 GFL Control
11.3.2 GFM Control
11.4 BESS Model
11.4.1 BESS Components
11.4.2 Battery Chemistry Types
11.5 Integrated BESS with GFM Inverter Model
11.5.1 Integrated Model: BESS
11.5.2 Integrated Model: DC/AC Filter
11.5.3 Integrated Model: DC-AC Converter
11.5.4 Integrated Model: Solar (PV) Panel
11.6 Grid-Connected/Islanded Large-Scale Battery Energy Storage Systems
11.7 Application: How to Develop the Model in a Software Platform (e.g., MATLAB/Simulink)
11.7.1 Detailed GFL Architecture
11.7.2 Detailed GFM Architecture
11.8 Simulation Results
11.8.1 Test System 1: BESS with a Single Machine
11.8.2 Cases on Test System 1
11.8.2.1 Case 1: GFL and GFM
11.8.2.2 Case 2: Step Change in Load in GFM with PV Supply
11.8.2.3 Case 3: Fault at PCC in GFM with PV Supply
11.8.3 Test System 2: BESS and PV Integrated with IEEE 13 Bus
11.8.4 Cases on Test System 2
11.8.4.1 Case 1: GFL and GFM
11.8.4.2 Case 2: Step Change in Load in GFM with PV Supply
11.8.4.3 Case 3: Fault at PCC in GFM with PV Supply
11.9 Chapter Summary and Conclusion
References
Chapter 12 Operation of Grid-Forming Inverters in Islanded Mode
12.1 Introduction
12.2 Control Models of the Studied MG Components
12.2.1 Modelling of WTs with Control Structure
12.2.2 Modelling a PV System with a Control Structure
12.2.3 Using Control Structure in ESS Modelling
12.2.4 Using a Control Structure for IPC Modelling
12.3 IPC Control Method Based on FCS-MPC
12.3.1 IPC Control Methods Based on the Studied MG's Operation Modes
12.4 For the Researched MG, an Integrated EMS with Coordinated Control
12.4.1 Mode 1 Operation (Standalone)
12.5 Results and Discussion of the Simulation
12.5.1 Step Change in AC Load with Higher SOC in Islanded Mode
12.5.2 Step Change in AC Load with Lower SOC in Islanded Mode
12.5.3 Regulation of DC Voltage in Rectification Mode with Constant DC Load
12.5.4 Under DC Voltage Variation, DC Voltage Regulation During Rectification
12.5.5 Under Low DC Load Variation, Rectification Mode DC Voltage Regulation
12.5.6 Under High DC Load Variation, Rectification Mode AC Voltage Regulation
12.5.7 Regulating the AC Voltage While Using an Islanded Inverter with a Constant AC Load
12.5.8 Regulation of AC Voltage in Islanded Inverter Mode with Variable AC Load
12.5.9 Under a Non-Linear AC Load, an Islanded Inverter Is Used
12.5.10 Comparison of Load Ripples and THD
12.6 Conclusion
Nomenclature
References
Index