Controlling the DC‐bus Voltage 9.2 Controlling the Power 9.3 Simulation Results 9.4 Experimental Results 9.5 Summary Chapter 10: Control of a DFIG Based Wind Turbine as a VSG (DFIG‐VSG) 10.1 Introduction 10.2 DFIG Based Wind Turbines 10.3 Differential Gears and Ancient Chinese South‐pointing Chariots 10.4 Analogy between a DFIG and Differential Gears 10.5 Control of a Grid‐side Converter 10.6 Control of the Rotor‐Side Converter 10.7 Regulation of System Frequency and Voltage 10.8 Simulation Results 10.9 Experimental Results 10.10 Summary Chapter 11: Synchronverter Based Transformerless Photovoltaic Systems 11.1 Introduction 11.2 Leakage Currents and Grounding of Grid‐tied Converters 11.3 Operation of a Conventional Half‐bridge Inverter 11.4 A Transformerless PV Inverter 11.5 Real‐time Simulation Results 11.6 Summary Chapter 12: Synchronverter Based STATCOM without an Dedicated Synchronization Unit 12.1 Introduction 12.2 Conventional Control of STATCOM 12.3 Synchronverter Based Control 12.4 Simulation Results 12.5 Summary Chapter 13: Synchronverters with Bounded Frequency and Voltage 13.1 Introduction 13.2 Model of the Original Synchronverter 13.3 Achieving Bounded Frequency and Voltage 13.4 Real‐time Simulation Results 13.5 Summary Chapter 14: Virtual Inertia, Virtual Damping, and Fault Ride‐through 14.1 Introduction 14.2 Inertia, the Inertia Time Constant, and the Inertia Constant 14.3 Limitation of the Inertia of a Synchronverter 14.4 Reconfiguration of the Inertia Time Constant 14.5 Reconfiguration of the Virtual Damping 14.6 Fault Ride‐through 14.7 Simulation Results 14.8 Experimental Results 14.9 Summary
12 Part III: 2G VSM: Robust Droop Controller Chapter 15: Synchronization Mechanism of Droop Control 15.1 Brief Review of Phase‐Locked Loops (PLLs) 15.2 Brief Review of Droop Control 15.3 Structural Resemblance between Droop Control and PLL 15.4 Operation of a Droop Controller as a Synchronization Unit 15.5 Experimental Results 15.6 Summary 16 Robust Droop Control 16.1 Control of Inverter Output Impedance 16.2 Inherent Limitations of Conventional Droop Control 16.3 Robust Droop Control of R‐inverters 16.4 Robust Droop Control of C‐inverters 16.5 Robust Droop Control of L‐inverters 16.6 Summary 17 Universal Droop Control 17.1 Introduction 17.2 Further Insights into Droop Control 17.3 Universal Droop Controller 17.4 Real‐time Simulation Results 17.5 Experimental Results 17.6 Summary 18 Self‐synchronized Universal Droop Controller 18.1 Description of the Controller 18.2 Operation of the Controller 18.3 Experimental Results 18.4 Real‐time Simulation Results from a Microgrid 18.5 Summary 19 Droop‐Controlled Loads for Continuous Demand Response